.site-footer[data-v-fac1cb98]{font-size:12px;line-height:normal;padding:16px max(28px,calc((100vw - 1380px)/2)) 14px;color:#8490a0;background:#fff;display:flex;flex-direction:column;gap:9px;border-top:1px solid #e2e8f0;margin-top:0}.footer-main[data-v-fac1cb98],.footer-filings[data-v-fac1cb98]{display:flex;align-items:center;justify-content:center;flex-wrap:wrap;gap:8px 24px}.footer-main b[data-v-fac1cb98]{color:#102d50;font-size:15px}.footer-main span[data-v-fac1cb98]{max-width:880px}.footer-main[data-v-fac1cb98]{min-height:54px}.footer-filings[data-v-fac1cb98]{gap:6px 22px}.site-footer a[data-v-fac1cb98]{color:#67758a}.footer-filings img[data-v-fac1cb98]{width:14px;height:14px;vertical-align:-2px;margin-right:4px}@media(max-width:760px){.site-footer[data-v-fac1cb98]:not(.round2-footer){padding:18px 18px 96px;display:grid;gap:5px}}.site-footer.round2-footer[data-v-fac1cb98]{display:block;text-align:center;font-size:11px;line-height:1.7;color:#8995a7;background:transparent;border:0;padding:0;margin-top:30px}@media(max-width:760px){.site-footer.round2-footer[data-v-fac1cb98]{padding-bottom:96px}}.prep-goal-label select[data-v-c2718303]{padding:9px 24px 9px 12px;font-size:13px;font-weight:800;color:#102d50;border-color:#e2e8f0;background:#f7f9fc;border-radius:8px}.prep-goal-label select.csp-goal[data-v-c2718303]{width:140px}@media(max-width:850px){.prep-goal-label select[data-v-c2718303]{font-size:12px;padding:8px}.prep-goal-label select.csp-goal[data-v-c2718303]{width:114px}}@media(max-width:380px){.prep-goal-label select[data-v-c2718303]{max-width:99px;padding-left:4px;padding-right:4px}}.site-header[data-v-a1f17b7b]{background:#fffffff5;-webkit-backdrop-filter:blur(14px);backdrop-filter:blur(14px)}.site-header-inner[data-v-a1f17b7b]{height:71px;min-height:71px;max-width:none;padding:0 max(24px,calc((100vw - 1440px)/2));gap:24px}.brand[data-v-a1f17b7b]{display:flex;align-items:center;flex-shrink:0;padding:0}.brand-logo[data-v-a1f17b7b]{display:block;width:104px;height:32px}.prep-context[data-v-a1f17b7b]{display:flex;align-items:center;flex:1;min-width:0;gap:28px}.site-header nav[data-v-a1f17b7b]{display:flex;gap:20px;flex:0 1 auto;align-self:auto;flex-wrap:nowrap;white-space:nowrap}.site-header nav a[data-v-a1f17b7b]{padding:25px 0 23px;font-size:13px;font-weight:700;color:#64748b;border-bottom:3px solid transparent}.site-header nav a.active[data-v-a1f17b7b]{color:#1d4fbd;border-bottom-color:#2f6fed}.round2-header nav[data-v-a1f17b7b]{line-height:1.7}.mobile-nav-toggle[data-v-a1f17b7b]{display:none;border:0;padding:5px;background:transparent;font-size:20px}.minimal-header[data-v-a1f17b7b]{position:static;-webkit-backdrop-filter:none;backdrop-filter:none;background:#fff}.minimal-header .site-header-inner[data-v-a1f17b7b]{min-height:0;height:auto;padding:18px 24px}.video-noi-link[data-v-a1f17b7b]{margin-left:auto;color:#66758b;font-size:14px}@media(max-width:1200px){.site-header-inner[data-v-a1f17b7b]{gap:18px;padding:0 20px}.prep-context[data-v-a1f17b7b]{gap:20px}.site-header nav[data-v-a1f17b7b]{gap:14px}.site-header nav a[data-v-a1f17b7b]{font-size:12px}}@media(max-width:1050px){.site-header-inner[data-v-a1f17b7b]{gap:14px}.prep-context[data-v-a1f17b7b]{gap:16px}.site-header nav[data-v-a1f17b7b]{gap:12px}}@media(max-width:850px){.site-header-inner[data-v-a1f17b7b]{height:61px;min-height:61px;gap:8px;padding:0 12px}.prep-context[data-v-a1f17b7b]{gap:0}.site-header-inner:not(.navigation-open):not(.noi-header):not(.round2-reading-header) nav[data-v-a1f17b7b]{display:none}.mobile-nav-toggle[data-v-a1f17b7b]{display:block}.navigation-open nav[data-v-a1f17b7b]{display:flex;position:absolute;top:62px;left:0;right:0;padding:14px 20px;background:#fff;box-shadow:0 8px 16px #14223512;border-top:1px solid #e2e8f0;flex-wrap:wrap;gap:8px 20px}.navigation-open nav a[data-v-a1f17b7b]{padding:10px 0}}@media(max-width:650px){.brand-logo[data-v-a1f17b7b]{width:94px;height:30px}.home-header .site-header-inner[data-v-a1f17b7b]{display:grid;grid-template-columns:auto 1fr auto;height:auto;padding-top:10px;padding-bottom:10px;row-gap:8px}.home-header .brand[data-v-a1f17b7b]{grid-column:1;grid-row:1}.home-header[data-v-a1f17b7b] .account-menu{grid-column:2;grid-row:1}.home-header .mobile-nav-toggle[data-v-a1f17b7b]{grid-column:3;grid-row:1}.home-header .prep-context[data-v-a1f17b7b]{grid-column:1 / -1;grid-row:2}.home-header[data-v-a1f17b7b] .prep-goal-label,.home-header[data-v-a1f17b7b] .prep-goal-label select{width:100%;max-width:none}.home-header .navigation-open nav[data-v-a1f17b7b]{top:100%}}@media(max-width:380px){.site-header-inner[data-v-a1f17b7b]{gap:5px;padding:0 8px}}@media(max-width:650px){.minimal-header .brand-logo[data-v-a1f17b7b]{width:104px;height:32px}.noi-header[data-v-a1f17b7b]{display:grid;grid-template-columns:auto 1fr auto;height:auto;padding:8px 14px;gap:4px 6px}.noi-header .brand[data-v-a1f17b7b]{grid-column:1;grid-row:1}.noi-header[data-v-a1f17b7b] .account-menu{grid-column:3;grid-row:1}.noi-header .prep-context[data-v-a1f17b7b]{grid-column:1/-1;grid-row:2;flex-direction:column;align-items:stretch;gap:4px}.noi-header nav[data-v-a1f17b7b]{display:flex;justify-content:space-between;width:100%}.noi-header nav a[data-v-a1f17b7b]{font-size:11px;padding:10px 0 8px}.noi-header .mobile-nav-toggle[data-v-a1f17b7b]{display:none}.noi-header[data-v-a1f17b7b]{font:15px/1.75 -apple-system,PingFang SC,Microsoft YaHei,sans-serif;row-gap:8px;min-height:0}.noi-header .brand-logo[data-v-a1f17b7b]{width:104px;height:32px}.noi-header[data-v-a1f17b7b] .prep-goal-label select{font:800 12px Microsoft YaHei UI,PingFang SC,Arial,sans-serif;padding:8px;width:114px}.noi-header nav[data-v-a1f17b7b]{gap:8px;line-height:1.75}.noi-header[data-v-a1f17b7b] .account-menu{gap:4px}.noi-header[data-v-a1f17b7b] .website-updates-entry{flex-basis:28px;width:28px;height:40px}.noi-header[data-v-a1f17b7b] .account-menu>button:not(.website-updates-entry){font:800 11px Arial;padding:6px 7px}.noi-header[data-v-a1f17b7b] .account-primary,.noi-header[data-v-a1f17b7b] .login-entry{display:block}}.round2-reading-header[data-v-a1f17b7b]{font:15px/1.7 Microsoft YaHei UI,PingFang SC,Arial,sans-serif}.round2-reading-header .brand-logo[data-v-a1f17b7b]{width:104px;height:32px}.round2-reading-header .mobile-nav-toggle[data-v-a1f17b7b]{display:none}.round2-reading-header[data-v-a1f17b7b] .account-primary,.round2-reading-header[data-v-a1f17b7b] .login-entry{display:inline-flex}.round2-reading-header[data-v-a1f17b7b] .website-updates-entry{flex-basis:40px;width:40px;height:40px}.round2-reading-header[data-v-a1f17b7b] .prep-goal-label select{font-size:13px;padding:9px 24px 9px 12px;max-width:none}.round2-reading-header[data-v-a1f17b7b] .prep-goal-label select.csp-goal{width:140px}@media(max-width:850px)and (min-width:521px){.round2-reading-header[data-v-a1f17b7b]{height:71px;min-height:71px;gap:18px;padding:0 20px;flex-wrap:nowrap}.round2-reading-header .prep-context[data-v-a1f17b7b]{gap:20px}}@media(max-width:520px){.round2-reading-header[data-v-a1f17b7b]{display:grid;grid-template-columns:auto 1fr auto;gap:4px 12px;padding:8px 14px;height:auto;min-height:56px}.round2-reading-header .brand[data-v-a1f17b7b]{grid-column:1;grid-row:1}.round2-reading-header[data-v-a1f17b7b] .account-menu{grid-column:3;grid-row:1;margin-left:0}.round2-reading-header .prep-context[data-v-a1f17b7b]{grid-column:1/-1;grid-row:2;flex-direction:column;align-items:stretch;gap:4px;padding-bottom:3px}.round2-reading-header nav[data-v-a1f17b7b]{width:100%;justify-content:space-between;gap:8px}.round2-reading-header nav a[data-v-a1f17b7b]{font-size:11px;padding:8px 0 6px;border-bottom-width:2px}}.browser-learning-panel{margin-bottom:1rem;padding:.6rem .8rem;border:1px solid var(--border, #dbe3ee);border-radius:.6rem;font-size:.9rem}.browser-learning-panel.compact{margin:24px 0 0;padding:0;border-color:transparent;background:transparent;font-size:12px}.browser-learning-panel.compact .browser-learning-heading{justify-content:flex-end}.browser-learning-panel.compact .browser-learning-heading button{border-color:transparent;padding:5px 0;background:transparent;color:#657489;font-size:12px}.browser-learning-panel button{font-size:12px;padding:6px 10px}.browser-learning-heading,.browser-learning-actions{display:flex;align-items:center;gap:.6rem;flex-wrap:wrap}.browser-learning-heading{justify-content:space-between}.browser-learning-actions{margin-top:.6rem}.browser-learning-actions p{flex-basis:100%;margin:.2rem 0}.wrong-book-control{margin-top:.5rem;display:flex;gap:.5rem;align-items:center;flex-wrap:wrap}.wrong-book-control button{font-size:12px;padding:5px 10px}.wrong-book-control.compact{margin:0}.wrong-book-control.compact button{display:grid;place-items:center;width:28px;height:28px;padding:4px;border-color:transparent;background:transparent;color:#8291a8}.wrong-book-control.compact button:hover:not(:disabled){color:#be554a;background:#fff1f0}.wrong-book-control.compact svg{width:16px;height:16px}.wrong-book-control .error{flex-basis:100%}.browser-learning-review{margin-top:.6rem;padding:.5rem .7rem;border-left:3px solid #ba731a;background:#fff6e8}.browser-learning-review p{margin:.2rem 0}@media print{.browser-learning-panel,.wrong-book-control{display:none}}.wrong-book-undo[data-v-da2eea9d]{position:fixed;bottom:24px;left:50%;transform:translate(-50%);z-index:50;display:flex;align-items:center;gap:12px;padding:12px 16px;max-width:calc(100vw - 24px);width:max-content;background:#fff;border:1px solid #d7e3f5;border-radius:12px;box-shadow:0 8px 30px #142e6026}:root{--blue-dark: #1d4fbd;--navy: #102d50;--paper: #f4f7fb}.auth-overlay{position:fixed;inset:0;z-index:100;display:grid;place-items:center;padding:20px;background:#091c3375;-webkit-backdrop-filter:blur(6px);backdrop-filter:blur(6px)}.auth-card{position:relative;width:min(430px,100%);max-height:calc(100dvh - 40px);overflow-y:auto;padding:30px;border-radius:20px;background:#fff;box-shadow:0 24px 70px #091c333d}.recovery-zone{margin-top:22px;padding-top:18px;border-top:1px solid var(--line)}.recovery-zone h3{margin:0 0 7px;font-size:16px}.recovery-hint{color:#64748b;font-size:12px;line-height:1.7;margin:8px 0}.recovery-preview{padding:9px 11px;border:1px solid #efd28c;border-radius:8px;background:#fff8e5;color:#805512;font-size:12px;line-height:1.6}.recovery-tabs{display:flex;gap:6px;padding:4px;background:#f1f5f9;border-radius:10px;margin-top:12px}.recovery-tabs button{flex:1;padding:9px;border:0;border-radius:7px;background:transparent;color:#536276;cursor:pointer;font-weight:700}.recovery-tabs button[aria-pressed=true]{background:#fff;color:var(--blue);box-shadow:0 1px 4px #14284b14}.recovery-code-row{display:flex;gap:8px}.recovery-code-row input{min-width:0;flex:1;letter-spacing:3px}.recovery-code-row button,.recovery-contact-item button{flex-shrink:0;padding:10px 12px;border:1px solid #c9daf7;border-radius:9px;background:#f3f7ff;color:#235bbd;cursor:pointer;font-weight:700}.recovery-code-row button:disabled{opacity:.55;cursor:default}.recovery-notice{margin:8px 0 0;color:#17654b;font-size:12px;line-height:1.7;overflow-wrap:anywhere}.recovery-error:empty,.recovery-notice:empty{display:none}.recovery-forgot{display:block;margin:12px 0 0 auto;padding:5px 0;border:0;background:none;color:var(--blue);cursor:pointer;font-size:13px}.recovery-contact-item{display:flex;align-items:center;justify-content:space-between;gap:12px;padding:12px 0;border-bottom:1px solid var(--line)}.recovery-contact-item strong{font-size:13px;display:block}.recovery-contact-item span{display:block;font-size:13px;color:#64748b;margin-top:5px;overflow-wrap:anywhere}.recovery-overlay{z-index:200}.recovery-account{padding:10px;border-radius:8px;background:#f4f7fb;color:#526176;font-size:13px}@media(min-width:700px){.register-card{width:min(760px,100%)}.register-card .auth-form-layout{display:grid;grid-template-columns:1fr 1fr;gap:26px;margin-top:22px}.register-card .auth-account-fields>label:first-child{margin-top:0}.register-card .recovery-zone{border-top:0;border-left:1px solid var(--line);padding:0 0 0 26px;margin:0}}@media(max-width:480px){.auth-overlay{padding:12px}.auth-card{padding:22px;max-height:calc(100dvh - 24px)}}.auth-card h2{margin:7px 0 8px;font-size:26px}.auth-help{margin:0 0 22px;color:var(--muted);font-size:13px;line-height:1.65}.auth-card label{display:block;margin:15px 0 7px;color:#526176;font-size:12px;font-weight:850}.auth-card input{width:100%;border:1px solid var(--line);border-radius:10px;padding:12px 13px;outline:none}.auth-card input:focus{border-color:#8cb1ff;box-shadow:0 0 0 3px #2f6fed1a}.auth-close{position:absolute;top:13px;right:14px;display:grid;place-items:center;width:34px;height:34px;padding:0;line-height:1;border:0;border-radius:50%;background:#f0f3f7;color:#607086;cursor:pointer;font-size:21px}.auth-submit,.auth-switch{width:100%;border-radius:10px;padding:11px 14px;cursor:pointer;font-weight:850}.auth-submit{margin-top:20px;border:0;background:var(--blue);color:#fff}.auth-submit:disabled{opacity:.55;cursor:wait}.auth-switch{margin-top:9px;border:0;background:transparent;color:var(--blue-dark)}.auth-error{margin:12px 0 0;padding:10px 12px;border-radius:9px;background:#fff0f0;color:#b34545;font-size:12px;line-height:1.5}.account-settings-card{width:min(520px,100%);max-height:calc(100vh - 40px);overflow-y:auto}.account-settings-identity{margin:22px 0;padding:16px;border:1px solid var(--line);border-radius:12px;background:#f8fafc;display:flex;align-items:center;justify-content:space-between;gap:18px}.account-settings-identity span{color:var(--muted);font-size:12px}.account-settings-identity strong{color:var(--navy)}.password-zone{padding:20px;border:1px solid var(--line);border-radius:14px;background:#f8fbff}.password-zone h3{margin:0 0 7px;font-size:17px}.password-zone>p:not(.password-feedback){margin:0 0 14px;color:var(--muted);font-size:12px;line-height:1.7}.password-zone label{margin-top:11px}.password-submit{width:100%;margin-top:17px;border:0;border-radius:9px;padding:10px 14px;background:var(--blue);color:#fff;cursor:pointer;font-weight:850}.password-submit:disabled{opacity:.55;cursor:wait}.password-feedback{margin:12px 0 0;padding:10px 12px;border-radius:9px;font-size:12px;line-height:1.5}.password-feedback.error{background:#fff0f0;color:#b34545}.password-feedback.success{background:#ecfaf3;color:#247553}.feedback-fab{position:fixed;right:22px;bottom:26px;z-index:60;border:1px solid #dbe7fb;border-radius:999px;background:#fff;color:var(--blue-dark);font-size:15px;font-weight:800;padding:14px 24px;cursor:pointer;box-shadow:0 8px 24px #1d32522e}.feedback-toast{position:fixed;left:50%;bottom:96px;transform:translate(-50%) translateY(14px);z-index:90;background:#1f2b3e;color:#fff;font-size:13px;font-weight:700;padding:12px 20px;border-radius:10px;box-shadow:0 10px 28px #14233c47;opacity:0;pointer-events:none;transition:opacity .25s,transform .25s;cursor:pointer;max-width:86vw}.feedback-toast.show{opacity:1;pointer-events:auto;transform:translate(-50%) translateY(0)}.feedback-fab:hover{border-color:var(--blue);background:#f7faff}.feedback-cats{display:flex;flex-wrap:wrap;gap:8px;margin:14px 0 4px}.feedback-cat{border:1px solid var(--line);border-radius:999px;background:#fff;color:#526176;font-size:12px;font-weight:800;padding:7px 13px;cursor:pointer}.feedback-cat.active{border-color:var(--blue);background:#f0f6ff;color:var(--blue-dark)}.feedback-card textarea{width:100%;border:1px solid var(--line);border-radius:10px;padding:12px 13px;outline:none;font:inherit;margin:12px 0 0;resize:vertical;box-sizing:border-box}.feedback-card input{margin-top:10px;box-sizing:border-box}.feedback-context{margin:10px 0 0;color:var(--muted);font-size:12px}.feedback-context code{background:#f1f5fb;border-radius:5px;padding:2px 6px}@media print{.feedback-fab{display:none}}.feedback-tabs{display:flex;gap:8px;margin-bottom:12px}.feedback-tab{flex:1;border:1px solid #d9e2f0;background:#fff;border-radius:8px;padding:8px 10px;cursor:pointer;font:inherit;color:#5b6472}.feedback-tab.active{border-color:var(--blue);background:#edf4ff;color:var(--blue);font-weight:600}.feedback-hint{font-size:12.5px;color:#8a94a6;margin:8px 0 0}.feedback-unread-dot{display:inline-block;width:8px;height:8px;border-radius:50%;background:#e5484d;margin-left:6px;vertical-align:middle}.feedback-msgs{display:flex;flex-direction:column;gap:10px;max-height:300px;overflow-y:auto}.feedback-thread{border:1px solid #e3e8f0;border-radius:10px;padding:10px 12px;margin-bottom:10px;background:#fbfcfe}.feedback-thread>b{display:block;font-size:13px;margin-bottom:8px}.feedback-handled{font-size:11px;color:#2f9e63;background:#e6f6ee;border-radius:6px;padding:1px 6px;margin-left:6px}.feedback-msg{max-width:88%;margin-bottom:6px;padding:7px 10px;border-radius:10px;font-size:13.5px;line-height:1.5}.feedback-msg span{display:block;white-space:pre-wrap;word-break:break-word}.feedback-msg small{display:block;font-size:11px;color:#98a2b3;margin-top:3px}.feedback-msg.admin{background:#eef3fb;border-top-left-radius:3px}.feedback-msg.mine{background:#e6f6ee;border-top-right-radius:3px;margin-left:auto}.feedback-reply{display:flex;flex-wrap:wrap;gap:6px;margin-top:8px}.feedback-reply input{flex:1;min-width:0;border:1px solid #d9e2f0;border-radius:8px;padding:7px 10px;font:inherit;font-size:13px}.feedback-reply>button{border:none;background:var(--blue);color:#fff;border-radius:8px;padding:7px 14px;cursor:pointer;font:inherit;font-size:13px}.feedback-reply>.feedback-images-compose{flex-basis:100%}.feedback-fab-dot{position:absolute;top:-6px;right:-4px;background:#e5484d;color:#fff;border-radius:999px;font-size:11px;font-style:normal;min-width:18px;height:18px;display:grid;place-items:center;padding:0 4px;font-weight:700}.feedback-fab.has-unread{animation:feedback-pulse 2s infinite}@keyframes feedback-pulse{0%,to{box-shadow:0 0 #e5484d00}50%{box-shadow:0 0 0 6px #e5484d40}}.account-menu{gap:8px}.account-menu .website-updates-entry{position:relative;display:inline-flex;align-items:center;justify-content:center;flex:0 0 40px;width:40px;height:40px;border:0;padding:0;background:transparent;color:#596779}.message-envelope{display:block;flex-shrink:0;transform:translateY(1px)}.account-menu .updates-dot{transform:translateY(1px)}.account-menu .website-updates-entry:hover{color:var(--blue)}.updates-dot{position:absolute;top:8px;right:7px;width:6px;height:6px;border-radius:50%;background:#e36b5d;box-shadow:0 0 0 2px #fff;pointer-events:none}.account-divider{width:1px;height:14px;background:#e1e6ed}.account-dropdown-wrap{position:relative}.account-menu button.account-name{display:flex;align-items:center;gap:6px;max-width:140px;padding:7px 5px;background:transparent;font-size:13px;font-weight:400}.compact-topbar .account-name span{display:block;overflow:hidden;text-overflow:ellipsis}.account-name .account-chevron{display:block;align-self:center;color:#8692a2;flex:0 0 12px;width:12px;height:12px}.account-menu button.account-name:hover,.account-menu button.account-name[aria-expanded=true]{background:#f1f4f8}.account-dropdown{position:absolute;top:calc(100% + 8px);right:0;min-width:148px;padding:5px;background:#fff;border:1px solid #e2e7ee;border-radius:12px;box-shadow:0 10px 35px #263d5826;z-index:110}.account-menu .account-dropdown button{display:block;width:100%;text-align:left;border:0;padding:10px 12px;font-size:13px;font-weight:400;border-radius:7px}.account-menu .account-dropdown button:hover,.account-menu .account-dropdown button:focus-visible{background:#f1f5fa;color:#2464b5}.account-menu button:focus-visible,.website-updates-card button:focus-visible{outline:2px solid #4279b9;outline-offset:3px}.website-updates-card{width:min(560px,calc(100vw - 32px));max-height:calc(100dvh - 64px);display:flex;flex-direction:column;border:1px solid #e3e8ef;background:#fff;border-radius:18px;box-shadow:0 24px 80px #10243b33;overflow:hidden}.website-updates-heading{display:flex;align-items:flex-start;justify-content:space-between;padding:25px 28px 18px;border-bottom:1px solid #edf0f4}.website-updates-heading h2{margin:0;font-size:21px;font-weight:600;color:#25364a}.website-updates-heading p{margin:8px 0 0;font-size:13px;color:#8290a0}.updates-close{background:transparent;border:0;color:#8390a0;width:30px;height:30px;font-size:25px;cursor:pointer;border-radius:6px}.updates-close:hover{background:#f1f4f8}.website-updates-list{overflow-y:auto;padding:0 28px}.website-update-item{padding:23px 0}.website-update-item+.website-update-item{border-top:1px solid #edf0f4}.website-update-item time{font-size:12px;color:#8895a5}.website-update-item h3{margin:8px 0 10px;color:#34465c;font-size:16px;line-height:1.6;font-weight:500}.website-update-item p{margin:0 0 13px;font-size:14px;line-height:1.8;color:#69788a}.update-action,.updates-retry,.updates-read-error button{border:0;background:transparent;color:#3274b9;padding:3px 0;cursor:pointer;font-size:13px}.update-action:hover{text-decoration:underline}.updates-state{padding:20px 0;color:#748195;font-size:14px}.updates-retry{margin-bottom:20px}.updates-read-error{margin:0;padding:10px 28px;border-top:1px solid #edf0f4;color:#a05f35;font-size:12px}.question-feedback-entry{padding:0;display:flex;align-items:center;flex-wrap:wrap;gap:6px}.question-feedback-prompt{color:var(--muted);font-size:14px;font-weight:400;line-height:1.5}.question-feedback-link{display:inline-flex;align-items:center;justify-content:center;gap:6px;min-height:36px;max-width:100%;border:0;border-radius:9px;padding:6px 16px;background:var(--blue);color:#fff;font:inherit;font-size:13px;font-weight:850;line-height:1.5;cursor:pointer}.question-feedback-link:hover{background:var(--blue-dark);color:#fff}.question-feedback-link:focus-visible{outline:2px solid var(--blue);outline-offset:3px}.question-feedback-unread{display:inline-block;width:7px;height:7px;margin-left:3px;border-radius:50%;background:#e5484d}@media print{.question-feedback-entry{display:none}}.register-card{width:min(760px,100%)}.register-card .auth-form-layout{display:grid;grid-template-columns:1fr 1fr;gap:26px;margin-top:22px}.register-card .auth-account-fields>label:first-child{margin-top:0}.register-card .recovery-zone{border-top:0;border-left:1px solid var(--line);padding:0 0 0 26px;margin:0}.account-menu.auth-status{flex-wrap:nowrap;gap:8px;flex-shrink:0;margin-left:auto}.account-menu>button{border:1px solid #e2e8f0;background:#fff;color:#536276;border-radius:9px;padding:7px 10px;cursor:pointer;font-size:12px;font-weight:800}.account-menu>button.account-primary{background:#2f6fed;color:#fff;border-color:#2f6fed}.account-menu .website-updates-entry{border:0;background:transparent;padding:0}.account-menu button.account-name{border:0;color:#102d50;border-radius:9px}.account-menu .account-dropdown{z-index:110}.account-menu .account-dropdown button{background:#fff}.auth-card .login-form{display:block}.auth-card .login-form button[type=submit]{width:100%;margin-top:20px;border:0;border-radius:10px;padding:11px 14px;background:#2f6fed;color:#fff;font-weight:850}.auth-card .eyebrow{margin:0}.auth-card h2{line-height:1.4}.auth-card .recovery-forgot{width:fit-content}.website-updates-card{padding:0}.website-updates-heading h2{margin:0;font-size:21px}.feedback-thread-head{display:flex;justify-content:space-between;font-size:12px;color:#64748b;margin-bottom:8px}.feedback-bubble{max-width:88%;margin-bottom:6px;padding:7px 10px;border-radius:10px;font-size:13.5px;line-height:1.5}.feedback-bubble p{margin:0;white-space:pre-wrap;overflow-wrap:anywhere}.feedback-bubble small{display:block;font-size:11px;color:#98a2b3;margin-bottom:3px}.feedback-bubble.admin{background:#eef3fb;border-top-left-radius:3px}.feedback-bubble.user{background:#e6f6ee;border-top-right-radius:3px;margin-left:auto}main:has(>.home-page){max-width:none;padding:0}main:has(>.noi-page),main:has(>.noi-payment-page),main:has(>.noi-video-page){max-width:none;padding:0;min-height:0}main:has(>.stats-page){min-height:0;max-width:none;padding:0}body:has(.programming-workspace.editing) .feedback-fab,body:has(.program-page.coding) .feedback-fab{display:none}body.program-desktop .feedback-fab{display:none}@media(max-width:850px){.account-menu.auth-status{gap:5px}.account-menu .website-updates-entry{flex-basis:44px;width:44px;height:44px}.account-menu .updates-dot{top:10px;right:9px}.account-menu button.account-name{max-width:80px;font-size:12px;gap:3px;padding:7px 3px}.practice-topbar .account-primary{display:none}.website-updates-heading{padding:22px 20px 18px}.website-updates-list{padding:0 20px}}@media(max-width:380px){.account-menu button.account-name{max-width:58px}}@media(max-width:639px){.register-card .auth-form-layout{grid-template-columns:1fr;gap:0}.register-card .recovery-zone{border-left:0;border-top:1px solid var(--line);padding:18px 0 0;margin-top:22px}}@media print{.auth-overlay,.feedback-fab{display:none!important}}.round2-feedback-card{width:min(540px,calc(100vw - 32px));max-height:calc(100dvh - 40px);border:1px solid #e1e8f0;border-radius:18px;padding:26px;color:#142235;box-shadow:0 20px 70px #14223533}.round2-feedback-card h2{font-size:22px;margin:0 0 18px}.round2-feedback-card .auth-close{top:20px;right:20px;border:0;background:transparent;font-size:26px;line-height:1;padding:6px;color:#66758b}.round2-feedback-card .feedback-tabs{border-bottom:1px solid #e1e8f0;padding-bottom:12px;margin-bottom:16px}.round2-feedback-card .feedback-tab{flex:0 0 auto;border:1px solid #d3def0;border-radius:9px;padding:8px 16px;background:#fff;color:#245ac0;font-weight:600}.round2-feedback-card .feedback-tab.active{background:#2f6fed;color:#fff;border-color:#2f6fed}.round2-feedback-card label{display:block;font-size:14px;font-weight:600;margin-top:14px}.round2-feedback-card select,.round2-feedback-card textarea{display:block;width:100%;padding:10px 12px;border:1px solid #ccd7e5;border-radius:9px;margin-top:7px;background:#fff;color:#142235}.round2-feedback-card textarea{max-height:35vh;min-height:70px}.round2-feedback-card .auth-submit{margin-top:8px}.round2-feedback-card .feedback-msgs{max-height:none}.round2-feedback-card .feedback-thread{border:0;border-top:1px solid #e1e8f0;border-radius:0;background:#fff;padding:16px 0}.round2-feedback-card .feedback-bubble{max-width:100%;padding:10px 12px;margin:8px 0;background:#f4f6fa;border-radius:9px}.round2-feedback-card .feedback-bubble.admin{background:#eef4ff}@media(max-width:640px){.round2-feedback-card{padding:20px}}.about-layout>main[data-v-0c6dc938]{max-width:none;margin:0;padding:0;min-height:100vh}@font-face{font-display:block;font-family:KaTeX_AMS;font-style:normal;font-weight:400;src:url(/assets/KaTeX_AMS-Regular-5085d14c.woff2) format("woff2"),url(/assets/KaTeX_AMS-Regular-cc9bd60e.woff) format("woff"),url(/assets/KaTeX_AMS-Regular-d1820025.ttf) format("truetype")}@font-face{font-display:block;font-family:KaTeX_Caligraphic;font-style:normal;font-weight:700;src:url(/assets/KaTeX_Caligraphic-Bold-eafc847d.woff2) format("woff2"),url(/assets/KaTeX_Caligraphic-Bold-4489718b.woff) format("woff"),url(/assets/KaTeX_Caligraphic-Bold-004d7c5d.ttf) format("truetype")}@font-face{font-display:block;font-family:KaTeX_Caligraphic;font-style:normal;font-weight:400;src:url(/assets/KaTeX_Caligraphic-Regular-e2ea347e.woff2) format("woff2"),url(/assets/KaTeX_Caligraphic-Regular-93440fab.woff) format("woff"),url(/assets/KaTeX_Caligraphic-Regular-305fded4.ttf) format("truetype")}@font-face{font-display:block;font-family:KaTeX_Fraktur;font-style:normal;font-weight:700;src:url(/assets/KaTeX_Fraktur-Bold-8bea0fdb.woff2) format("woff2"),url(/assets/KaTeX_Fraktur-Bold-6c0cfe75.woff) format("woff"),url(/assets/KaTeX_Fraktur-Bold-5d9c444d.ttf) format("truetype")}@font-face{font-display:block;font-family:KaTeX_Fraktur;font-style:normal;font-weight:400;src:url(/assets/KaTeX_Fraktur-Regular-9362217a.woff2) format("woff2"),url(/assets/KaTeX_Fraktur-Regular-f175ce1c.woff) format("woff"),url(/assets/KaTeX_Fraktur-Regular-81ff0bab.ttf) format("truetype")}@font-face{font-display:block;font-family:KaTeX_Main;font-style:normal;font-weight:700;src:url(/assets/KaTeX_Main-Bold-b1f7ce88.woff2) format("woff2"),url(/assets/KaTeX_Main-Bold-099b7008.woff) format("woff"),url(/assets/KaTeX_Main-Bold-306a8395.ttf) format("truetype")}@font-face{font-display:block;font-family:KaTeX_Main;font-style:italic;font-weight:700;src:url(/assets/KaTeX_Main-BoldItalic-f10c9dc0.woff2) format("woff2"),url(/assets/KaTeX_Main-BoldItalic-12a522d1.woff) format("woff"),url(/assets/KaTeX_Main-BoldItalic-f3c4f326.ttf) format("truetype")}@font-face{font-display:block;font-family:KaTeX_Main;font-style:italic;font-weight:400;src:url(/assets/KaTeX_Main-Italic-0d580ede.woff2) format("woff2"),url(/assets/KaTeX_Main-Italic-4c2ce066.woff) format("woff"),url(/assets/KaTeX_Main-Italic-3759e9c6.ttf) format("truetype")}@font-face{font-display:block;font-family:KaTeX_Main;font-style:normal;font-weight:400;src:url(/assets/KaTeX_Main-Regular-76d8dbe2.woff2) format("woff2"),url(/assets/KaTeX_Main-Regular-ebf7825a.woff) format("woff"),url(/assets/KaTeX_Main-Regular-32a59bcd.ttf) format("truetype")}@font-face{font-display:block;font-family:KaTeX_Math;font-style:italic;font-weight:700;src:url(/assets/KaTeX_Math-BoldItalic-999ef36c.woff2) format("woff2"),url(/assets/KaTeX_Math-BoldItalic-2263edb0.woff) format("woff"),url(/assets/KaTeX_Math-BoldItalic-775d28df.ttf) format("truetype")}@font-face{font-display:block;font-family:KaTeX_Math;font-style:italic;font-weight:400;src:url(/assets/KaTeX_Math-Italic-2de77004.woff2) format("woff2"),url(/assets/KaTeX_Math-Italic-c0d3ffcf.woff) format("woff"),url(/assets/KaTeX_Math-Italic-1f94eaff.ttf) format("truetype")}@font-face{font-display:block;font-family:KaTeX_SansSerif;font-style:normal;font-weight:700;src:url(/assets/KaTeX_SansSerif-Bold-f5b144b4.woff2) format("woff2"),url(/assets/KaTeX_SansSerif-Bold-db22128e.woff) format("woff"),url(/assets/KaTeX_SansSerif-Bold-8531ea67.ttf) format("truetype")}@font-face{font-display:block;font-family:KaTeX_SansSerif;font-style:italic;font-weight:400;src:url(/assets/KaTeX_SansSerif-Italic-b71f456a.woff2) format("woff2"),url(/assets/KaTeX_SansSerif-Italic-033768fb.woff) format("woff"),url(/assets/KaTeX_SansSerif-Italic-18623275.ttf) format("truetype")}@font-face{font-display:block;font-family:KaTeX_SansSerif;font-style:normal;font-weight:400;src:url(/assets/KaTeX_SansSerif-Regular-c30429e5.woff2) format("woff2"),url(/assets/KaTeX_SansSerif-Regular-92e9fa94.woff) format("woff"),url(/assets/KaTeX_SansSerif-Regular-4da3b851.ttf) format("truetype")}@font-face{font-display:block;font-family:KaTeX_Script;font-style:normal;font-weight:400;src:url(/assets/KaTeX_Script-Regular-f7c0859f.woff2) format("woff2"),url(/assets/KaTeX_Script-Regular-f9c90562.woff) format("woff"),url(/assets/KaTeX_Script-Regular-b9264196.ttf) format("truetype")}@font-face{font-display:block;font-family:KaTeX_Size1;font-style:normal;font-weight:400;src:url(/assets/KaTeX_Size1-Regular-26083f26.woff2) format("woff2"),url(/assets/KaTeX_Size1-Regular-b5f79b67.woff) format("woff"),url(/assets/KaTeX_Size1-Regular-dbb27b9e.ttf) format("truetype")}@font-face{font-display:block;font-family:KaTeX_Size2;font-style:normal;font-weight:400;src:url(/assets/KaTeX_Size2-Regular-f2e1dc7d.woff2) format("woff2"),url(/assets/KaTeX_Size2-Regular-280f5b5c.woff) format("woff"),url(/assets/KaTeX_Size2-Regular-7b80a516.ttf) format("truetype")}@font-face{font-display:block;font-family:KaTeX_Size3;font-style:normal;font-weight:400;src:url(data:font/woff2;base64,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) format("woff2"),url(/assets/KaTeX_Size3-Regular-93ab932a.woff) format("woff"),url(/assets/KaTeX_Size3-Regular-e0a57b34.ttf) format("truetype")}@font-face{font-display:block;font-family:KaTeX_Size4;font-style:normal;font-weight:400;src:url(/assets/KaTeX_Size4-Regular-e5e65c59.woff2) format("woff2"),url(/assets/KaTeX_Size4-Regular-45fb8824.woff) format("woff"),url(/assets/KaTeX_Size4-Regular-d6141bf4.ttf) format("truetype")}@font-face{font-display:block;font-family:KaTeX_Typewriter;font-style:normal;font-weight:400;src:url(/assets/KaTeX_Typewriter-Regular-8eeabe21.woff2) format("woff2"),url(/assets/KaTeX_Typewriter-Regular-b4c52f66.woff) format("woff"),url(/assets/KaTeX_Typewriter-Regular-f721beff.ttf) format("truetype")}.katex{font: 1.21em KaTeX_Main,Times New Roman,serif;line-height:1.2;position:relative;text-indent:0;text-rendering:auto}.katex *{-ms-high-contrast-adjust:none!important;border-color:currentColor}.katex .katex-version:after{content:"0.16.47"}.katex .katex-mathml{border:0;-webkit-clip-path:inset(50%);clip-path:inset(50%);height:1px;overflow:hidden;padding:0;position:absolute;width:1px}.katex .katex-html>.newline{display:block}.katex .base{position:relative;white-space:nowrap;width:-webkit-min-content;width:-moz-min-content;width:min-content}.katex .base,.katex .strut{display:inline-block}.katex .textbf{font-weight:700}.katex .textit{font-style:italic}.katex .textrm{font-family:KaTeX_Main}.katex .textsf{font-family:KaTeX_SansSerif}.katex .texttt{font-family:KaTeX_Typewriter}.katex .mathnormal{font-family:KaTeX_Math;font-style:italic}.katex .mathit{font-family:KaTeX_Main;font-style:italic}.katex .mathrm{font-style:normal}.katex .mathbf{font-family:KaTeX_Main;font-weight:700}.katex .boldsymbol{font-family:KaTeX_Math;font-style:italic;font-weight:700}.katex .amsrm,.katex .mathbb,.katex .textbb{font-family:KaTeX_AMS}.katex .mathcal{font-family:KaTeX_Caligraphic}.katex .mathfrak,.katex .textfrak{font-family:KaTeX_Fraktur}.katex .mathboldfrak,.katex .textboldfrak{font-family:KaTeX_Fraktur;font-weight:700}.katex .mathtt{font-family:KaTeX_Typewriter}.katex .mathscr,.katex .textscr{font-family:KaTeX_Script}.katex .mathsf,.katex .textsf{font-family:KaTeX_SansSerif}.katex .mathboldsf,.katex .textboldsf{font-family:KaTeX_SansSerif;font-weight:700}.katex .mathitsf,.katex .mathsfit,.katex .textitsf{font-family:KaTeX_SansSerif;font-style:italic}.katex .mainrm{font-family:KaTeX_Main;font-style:normal}.katex .vlist-t{border-collapse:collapse;display:inline-table;table-layout:fixed}.katex .vlist-r{display:table-row}.katex .vlist{display:table-cell;position:relative;vertical-align:bottom}.katex .vlist>span{display:block;height:0;position:relative}.katex .vlist>span>span{display:inline-block}.katex .vlist>span>.pstrut{overflow:hidden;width:0}.katex .vlist-t2{margin-right:-2px}.katex .vlist-s{display:table-cell;font-size:1px;min-width:2px;vertical-align:bottom;width:2px}.katex .vbox{align-items:baseline;display:inline-flex;flex-direction:column}.katex .hbox{width:100%}.katex .hbox,.katex .thinbox{display:inline-flex;flex-direction:row}.katex .thinbox{max-width:0;width:0}.katex .msupsub{text-align:left}.katex .mfrac>span>span{text-align:center}.katex .mfrac .frac-line{border-bottom-style:solid;display:inline-block;width:100%}.katex .hdashline,.katex .hline,.katex .mfrac .frac-line,.katex .overline .overline-line,.katex .rule,.katex .underline .underline-line{min-height:1px}.katex .mspace{display:inline-block}.katex .smash{display:inline;line-height:0}.katex .clap,.katex .llap,.katex .rlap{position:relative;width:0}.katex .clap>.inner,.katex .llap>.inner,.katex .rlap>.inner{position:absolute}.katex .clap>.fix,.katex .llap>.fix,.katex .rlap>.fix{display:inline-block}.katex .llap>.inner{right:0}.katex .clap>.inner,.katex .rlap>.inner{left:0}.katex .clap>.inner>span{margin-left:-50%;margin-right:50%}.katex .rule{border:0 solid;display:inline-block;position:relative}.katex .hline,.katex .overline .overline-line,.katex .underline .underline-line{border-bottom-style:solid;display:inline-block;width:100%}.katex .hdashline{border-bottom-style:dashed;display:inline-block;width:100%}.katex .sqrt>.root{margin-left:.2777777778em;margin-right:-.5555555556em}.katex .fontsize-ensurer.reset-size1.size1,.katex .sizing.reset-size1.size1{font-size:1em}.katex .fontsize-ensurer.reset-size1.size2,.katex .sizing.reset-size1.size2{font-size:1.2em}.katex .fontsize-ensurer.reset-size1.size3,.katex .sizing.reset-size1.size3{font-size:1.4em}.katex .fontsize-ensurer.reset-size1.size4,.katex .sizing.reset-size1.size4{font-size:1.6em}.katex .fontsize-ensurer.reset-size1.size5,.katex .sizing.reset-size1.size5{font-size:1.8em}.katex .fontsize-ensurer.reset-size1.size6,.katex .sizing.reset-size1.size6{font-size:2em}.katex .fontsize-ensurer.reset-size1.size7,.katex .sizing.reset-size1.size7{font-size:2.4em}.katex .fontsize-ensurer.reset-size1.size8,.katex .sizing.reset-size1.size8{font-size:2.88em}.katex .fontsize-ensurer.reset-size1.size9,.katex .sizing.reset-size1.size9{font-size:3.456em}.katex .fontsize-ensurer.reset-size1.size10,.katex .sizing.reset-size1.size10{font-size:4.148em}.katex .fontsize-ensurer.reset-size1.size11,.katex .sizing.reset-size1.size11{font-size:4.976em}.katex .fontsize-ensurer.reset-size2.size1,.katex .sizing.reset-size2.size1{font-size:.8333333333em}.katex .fontsize-ensurer.reset-size2.size2,.katex .sizing.reset-size2.size2{font-size:1em}.katex .fontsize-ensurer.reset-size2.size3,.katex .sizing.reset-size2.size3{font-size:1.1666666667em}.katex .fontsize-ensurer.reset-size2.size4,.katex .sizing.reset-size2.size4{font-size:1.3333333333em}.katex .fontsize-ensurer.reset-size2.size5,.katex .sizing.reset-size2.size5{font-size:1.5em}.katex .fontsize-ensurer.reset-size2.size6,.katex .sizing.reset-size2.size6{font-size:1.6666666667em}.katex .fontsize-ensurer.reset-size2.size7,.katex .sizing.reset-size2.size7{font-size:2em}.katex .fontsize-ensurer.reset-size2.size8,.katex .sizing.reset-size2.size8{font-size:2.4em}.katex .fontsize-ensurer.reset-size2.size9,.katex .sizing.reset-size2.size9{font-size:2.88em}.katex .fontsize-ensurer.reset-size2.size10,.katex .sizing.reset-size2.size10{font-size:3.4566666667em}.katex .fontsize-ensurer.reset-size2.size11,.katex .sizing.reset-size2.size11{font-size:4.1466666667em}.katex .fontsize-ensurer.reset-size3.size1,.katex .sizing.reset-size3.size1{font-size:.7142857143em}.katex .fontsize-ensurer.reset-size3.size2,.katex .sizing.reset-size3.size2{font-size:.8571428571em}.katex .fontsize-ensurer.reset-size3.size3,.katex .sizing.reset-size3.size3{font-size:1em}.katex .fontsize-ensurer.reset-size3.size4,.katex .sizing.reset-size3.size4{font-size:1.1428571429em}.katex .fontsize-ensurer.reset-size3.size5,.katex .sizing.reset-size3.size5{font-size:1.2857142857em}.katex .fontsize-ensurer.reset-size3.size6,.katex .sizing.reset-size3.size6{font-size:1.4285714286em}.katex .fontsize-ensurer.reset-size3.size7,.katex .sizing.reset-size3.size7{font-size:1.7142857143em}.katex .fontsize-ensurer.reset-size3.size8,.katex .sizing.reset-size3.size8{font-size:2.0571428571em}.katex .fontsize-ensurer.reset-size3.size9,.katex .sizing.reset-size3.size9{font-size:2.4685714286em}.katex .fontsize-ensurer.reset-size3.size10,.katex .sizing.reset-size3.size10{font-size:2.9628571429em}.katex .fontsize-ensurer.reset-size3.size11,.katex .sizing.reset-size3.size11{font-size:3.5542857143em}.katex .fontsize-ensurer.reset-size4.size1,.katex .sizing.reset-size4.size1{font-size:.625em}.katex .fontsize-ensurer.reset-size4.size2,.katex .sizing.reset-size4.size2{font-size:.75em}.katex .fontsize-ensurer.reset-size4.size3,.katex .sizing.reset-size4.size3{font-size:.875em}.katex .fontsize-ensurer.reset-size4.size4,.katex .sizing.reset-size4.size4{font-size:1em}.katex .fontsize-ensurer.reset-size4.size5,.katex .sizing.reset-size4.size5{font-size:1.125em}.katex .fontsize-ensurer.reset-size4.size6,.katex .sizing.reset-size4.size6{font-size:1.25em}.katex .fontsize-ensurer.reset-size4.size7,.katex .sizing.reset-size4.size7{font-size:1.5em}.katex .fontsize-ensurer.reset-size4.size8,.katex .sizing.reset-size4.size8{font-size:1.8em}.katex .fontsize-ensurer.reset-size4.size9,.katex .sizing.reset-size4.size9{font-size:2.16em}.katex .fontsize-ensurer.reset-size4.size10,.katex .sizing.reset-size4.size10{font-size:2.5925em}.katex .fontsize-ensurer.reset-size4.size11,.katex .sizing.reset-size4.size11{font-size:3.11em}.katex .fontsize-ensurer.reset-size5.size1,.katex .sizing.reset-size5.size1{font-size:.5555555556em}.katex .fontsize-ensurer.reset-size5.size2,.katex .sizing.reset-size5.size2{font-size:.6666666667em}.katex .fontsize-ensurer.reset-size5.size3,.katex .sizing.reset-size5.size3{font-size:.7777777778em}.katex .fontsize-ensurer.reset-size5.size4,.katex .sizing.reset-size5.size4{font-size:.8888888889em}.katex .fontsize-ensurer.reset-size5.size5,.katex .sizing.reset-size5.size5{font-size:1em}.katex .fontsize-ensurer.reset-size5.size6,.katex .sizing.reset-size5.size6{font-size:1.1111111111em}.katex .fontsize-ensurer.reset-size5.size7,.katex .sizing.reset-size5.size7{font-size:1.3333333333em}.katex .fontsize-ensurer.reset-size5.size8,.katex .sizing.reset-size5.size8{font-size:1.6em}.katex .fontsize-ensurer.reset-size5.size9,.katex .sizing.reset-size5.size9{font-size:1.92em}.katex .fontsize-ensurer.reset-size5.size10,.katex .sizing.reset-size5.size10{font-size:2.3044444444em}.katex .fontsize-ensurer.reset-size5.size11,.katex .sizing.reset-size5.size11{font-size:2.7644444444em}.katex .fontsize-ensurer.reset-size6.size1,.katex .sizing.reset-size6.size1{font-size:.5em}.katex .fontsize-ensurer.reset-size6.size2,.katex .sizing.reset-size6.size2{font-size:.6em}.katex .fontsize-ensurer.reset-size6.size3,.katex .sizing.reset-size6.size3{font-size:.7em}.katex .fontsize-ensurer.reset-size6.size4,.katex .sizing.reset-size6.size4{font-size:.8em}.katex .fontsize-ensurer.reset-size6.size5,.katex .sizing.reset-size6.size5{font-size:.9em}.katex .fontsize-ensurer.reset-size6.size6,.katex .sizing.reset-size6.size6{font-size:1em}.katex .fontsize-ensurer.reset-size6.size7,.katex .sizing.reset-size6.size7{font-size:1.2em}.katex .fontsize-ensurer.reset-size6.size8,.katex .sizing.reset-size6.size8{font-size:1.44em}.katex .fontsize-ensurer.reset-size6.size9,.katex .sizing.reset-size6.size9{font-size:1.728em}.katex .fontsize-ensurer.reset-size6.size10,.katex .sizing.reset-size6.size10{font-size:2.074em}.katex .fontsize-ensurer.reset-size6.size11,.katex .sizing.reset-size6.size11{font-size:2.488em}.katex .fontsize-ensurer.reset-size7.size1,.katex .sizing.reset-size7.size1{font-size:.4166666667em}.katex .fontsize-ensurer.reset-size7.size2,.katex .sizing.reset-size7.size2{font-size:.5em}.katex .fontsize-ensurer.reset-size7.size3,.katex .sizing.reset-size7.size3{font-size:.5833333333em}.katex .fontsize-ensurer.reset-size7.size4,.katex .sizing.reset-size7.size4{font-size:.6666666667em}.katex .fontsize-ensurer.reset-size7.size5,.katex .sizing.reset-size7.size5{font-size:.75em}.katex .fontsize-ensurer.reset-size7.size6,.katex .sizing.reset-size7.size6{font-size:.8333333333em}.katex .fontsize-ensurer.reset-size7.size7,.katex .sizing.reset-size7.size7{font-size:1em}.katex .fontsize-ensurer.reset-size7.size8,.katex .sizing.reset-size7.size8{font-size:1.2em}.katex .fontsize-ensurer.reset-size7.size9,.katex .sizing.reset-size7.size9{font-size:1.44em}.katex .fontsize-ensurer.reset-size7.size10,.katex .sizing.reset-size7.size10{font-size:1.7283333333em}.katex .fontsize-ensurer.reset-size7.size11,.katex .sizing.reset-size7.size11{font-size:2.0733333333em}.katex .fontsize-ensurer.reset-size8.size1,.katex .sizing.reset-size8.size1{font-size:.3472222222em}.katex .fontsize-ensurer.reset-size8.size2,.katex .sizing.reset-size8.size2{font-size:.4166666667em}.katex .fontsize-ensurer.reset-size8.size3,.katex .sizing.reset-size8.size3{font-size:.4861111111em}.katex .fontsize-ensurer.reset-size8.size4,.katex .sizing.reset-size8.size4{font-size:.5555555556em}.katex .fontsize-ensurer.reset-size8.size5,.katex .sizing.reset-size8.size5{font-size:.625em}.katex .fontsize-ensurer.reset-size8.size6,.katex .sizing.reset-size8.size6{font-size:.6944444444em}.katex .fontsize-ensurer.reset-size8.size7,.katex .sizing.reset-size8.size7{font-size:.8333333333em}.katex .fontsize-ensurer.reset-size8.size8,.katex .sizing.reset-size8.size8{font-size:1em}.katex .fontsize-ensurer.reset-size8.size9,.katex .sizing.reset-size8.size9{font-size:1.2em}.katex .fontsize-ensurer.reset-size8.size10,.katex .sizing.reset-size8.size10{font-size:1.4402777778em}.katex .fontsize-ensurer.reset-size8.size11,.katex .sizing.reset-size8.size11{font-size:1.7277777778em}.katex .fontsize-ensurer.reset-size9.size1,.katex .sizing.reset-size9.size1{font-size:.2893518519em}.katex .fontsize-ensurer.reset-size9.size2,.katex .sizing.reset-size9.size2{font-size:.3472222222em}.katex .fontsize-ensurer.reset-size9.size3,.katex .sizing.reset-size9.size3{font-size:.4050925926em}.katex .fontsize-ensurer.reset-size9.size4,.katex .sizing.reset-size9.size4{font-size:.462962963em}.katex .fontsize-ensurer.reset-size9.size5,.katex .sizing.reset-size9.size5{font-size:.5208333333em}.katex .fontsize-ensurer.reset-size9.size6,.katex .sizing.reset-size9.size6{font-size:.5787037037em}.katex .fontsize-ensurer.reset-size9.size7,.katex .sizing.reset-size9.size7{font-size:.6944444444em}.katex .fontsize-ensurer.reset-size9.size8,.katex .sizing.reset-size9.size8{font-size:.8333333333em}.katex .fontsize-ensurer.reset-size9.size9,.katex .sizing.reset-size9.size9{font-size:1em}.katex .fontsize-ensurer.reset-size9.size10,.katex .sizing.reset-size9.size10{font-size:1.2002314815em}.katex .fontsize-ensurer.reset-size9.size11,.katex .sizing.reset-size9.size11{font-size:1.4398148148em}.katex .fontsize-ensurer.reset-size10.size1,.katex .sizing.reset-size10.size1{font-size:.2410800386em}.katex .fontsize-ensurer.reset-size10.size2,.katex .sizing.reset-size10.size2{font-size:.2892960463em}.katex .fontsize-ensurer.reset-size10.size3,.katex .sizing.reset-size10.size3{font-size:.337512054em}.katex .fontsize-ensurer.reset-size10.size4,.katex .sizing.reset-size10.size4{font-size:.3857280617em}.katex .fontsize-ensurer.reset-size10.size5,.katex .sizing.reset-size10.size5{font-size:.4339440694em}.katex .fontsize-ensurer.reset-size10.size6,.katex .sizing.reset-size10.size6{font-size:.4821600771em}.katex .fontsize-ensurer.reset-size10.size7,.katex .sizing.reset-size10.size7{font-size:.5785920926em}.katex .fontsize-ensurer.reset-size10.size8,.katex .sizing.reset-size10.size8{font-size:.6943105111em}.katex .fontsize-ensurer.reset-size10.size9,.katex .sizing.reset-size10.size9{font-size:.8331726133em}.katex .fontsize-ensurer.reset-size10.size10,.katex .sizing.reset-size10.size10{font-size:1em}.katex .fontsize-ensurer.reset-size10.size11,.katex .sizing.reset-size10.size11{font-size:1.1996142719em}.katex .fontsize-ensurer.reset-size11.size1,.katex .sizing.reset-size11.size1{font-size:.2009646302em}.katex .fontsize-ensurer.reset-size11.size2,.katex .sizing.reset-size11.size2{font-size:.2411575563em}.katex .fontsize-ensurer.reset-size11.size3,.katex .sizing.reset-size11.size3{font-size:.2813504823em}.katex .fontsize-ensurer.reset-size11.size4,.katex .sizing.reset-size11.size4{font-size:.3215434084em}.katex .fontsize-ensurer.reset-size11.size5,.katex .sizing.reset-size11.size5{font-size:.3617363344em}.katex .fontsize-ensurer.reset-size11.size6,.katex .sizing.reset-size11.size6{font-size:.4019292605em}.katex .fontsize-ensurer.reset-size11.size7,.katex .sizing.reset-size11.size7{font-size:.4823151125em}.katex .fontsize-ensurer.reset-size11.size8,.katex .sizing.reset-size11.size8{font-size:.578778135em}.katex .fontsize-ensurer.reset-size11.size9,.katex .sizing.reset-size11.size9{font-size:.6945337621em}.katex .fontsize-ensurer.reset-size11.size10,.katex .sizing.reset-size11.size10{font-size:.8336012862em}.katex .fontsize-ensurer.reset-size11.size11,.katex .sizing.reset-size11.size11{font-size:1em}.katex .delimsizing.size1{font-family:KaTeX_Size1}.katex .delimsizing.size2{font-family:KaTeX_Size2}.katex .delimsizing.size3{font-family:KaTeX_Size3}.katex .delimsizing.size4{font-family:KaTeX_Size4}.katex .delimsizing.mult .delim-size1>span{font-family:KaTeX_Size1}.katex .delimsizing.mult .delim-size4>span{font-family:KaTeX_Size4}.katex .nulldelimiter{display:inline-block;width:.12em}.katex .delimcenter,.katex .op-symbol{position:relative}.katex .op-symbol.small-op{font-family:KaTeX_Size1}.katex .op-symbol.large-op{font-family:KaTeX_Size2}.katex .accent>.vlist-t,.katex .op-limits>.vlist-t{text-align:center}.katex .accent .accent-body{position:relative}.katex .accent .accent-body:not(.accent-full){width:0}.katex .overlay{display:block}.katex .mtable .vertical-separator{display:inline-block;min-width:1px}.katex .mtable .arraycolsep{display:inline-block}.katex .mtable .col-align-c>.vlist-t{text-align:center}.katex .mtable .col-align-l>.vlist-t{text-align:left}.katex .mtable .col-align-r>.vlist-t{text-align:right}.katex .svg-align{text-align:left}.katex svg{fill:currentColor;stroke:currentColor;display:block;height:inherit;position:absolute;width:100%}.katex svg path{stroke:none}.katex svg{fill-rule:nonzero;fill-opacity:1;stroke-width:1;stroke-linecap:butt;stroke-linejoin:miter;stroke-miterlimit:4;stroke-dasharray:none;stroke-dashoffset:0;stroke-opacity:1}.katex img{border-style:none;max-height:none;max-width:none;min-height:0;min-width:0}.katex .stretchy{display:block;overflow:hidden;position:relative;width:100%}.katex .stretchy:after,.katex .stretchy:before{content:""}.katex .hide-tail{overflow:hidden;position:relative;width:100%}.katex .halfarrow-left{left:0;overflow:hidden;position:absolute;width:50.2%}.katex .halfarrow-right{overflow:hidden;position:absolute;right:0;width:50.2%}.katex .brace-left{left:0;overflow:hidden;position:absolute;width:25.1%}.katex .brace-center{left:25%;overflow:hidden;position:absolute;width:50%}.katex .brace-right{overflow:hidden;position:absolute;right:0;width:25.1%}.katex .x-arrow-pad{padding:0 .5em}.katex .cd-arrow-pad{padding:0 .55556em 0 .27778em}.katex .mover,.katex .munder,.katex .x-arrow{text-align:center}.katex .boxpad{padding:0 .3em}.katex .fbox,.katex .fcolorbox{border:.04em solid;box-sizing:border-box}.katex .cancel-pad{padding:0 .2em}.katex .cancel-lap{margin-left:-.2em;margin-right:-.2em}.katex .sout{border-bottom-style:solid;border-bottom-width:.08em}.katex .angl{border-right:.049em solid;border-top:.049em solid;box-sizing:border-box;margin-right:.03889em}.katex .anglpad{padding:0 .03889em}.katex .eqn-num:before{content:"(" counter(katexEqnNo) ")";counter-increment:katexEqnNo}.katex .mml-eqn-num:before{content:"(" counter(mmlEqnNo) ")";counter-increment:mmlEqnNo}.katex .mtr-glue{width:50%}.katex .cd-vert-arrow{display:inline-block;position:relative}.katex .cd-label-left{display:inline-block;position:absolute;right:calc(50% + .3em);text-align:left}.katex .cd-label-right{display:inline-block;left:calc(50% + .3em);position:absolute;text-align:right}.katex-display{display:block;margin:1em 0;text-align:center}.katex-display>.katex{display:block;text-align:center;white-space:nowrap}.katex-display>.katex>.katex-html{display:block;position:relative}.katex-display>.katex>.katex-html>.tag{position:absolute;right:0}.katex-display.leqno>.katex>.katex-html>.tag{left:0;right:auto}.katex-display.fleqn>.katex{padding-left:2em;text-align:left}body{counter-reset:katexEqnNo mmlEqnNo}:root{--ink: #142235;--muted: #657489;--line: #e2e8f0;--blue: #2f6fed;--site-width: 1440px;font-family:Microsoft YaHei UI,PingFang SC,Arial,sans-serif;font-size:16px;color:var(--ink);background:#f4f7fb;font-synthesis:none;line-height:normal}*{box-sizing:border-box}body{margin:0}a{color:var(--blue);text-decoration:none}button,input,select{font:inherit}button{cursor:pointer;border:1px solid #d4ddea;border-radius:9px;background:#fff;color:#24426b;padding:9px 18px}button:disabled{opacity:.4;cursor:default}button:hover:not(:disabled){border-color:#3872e9}a:focus-visible,button:focus-visible,input:focus-visible,select:focus-visible,summary:focus-visible{outline:3px solid #81adff;outline-offset:3px}.site-header{background:#fff;border-bottom:1px solid var(--line);position:sticky;top:0;z-index:30}.site-header-inner{display:flex;align-items:center;gap:28px;max-width:var(--site-width);margin:auto;padding:0 30px;min-height:72px}.auth-status{margin-left:auto;display:flex;align-items:center;gap:10px;flex-wrap:wrap;font-size:14px}.account-name{max-width:130px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.auth-status button{padding:6px 10px}.auth-status-error{max-width:220px;color:#b42318}.login-card{max-width:440px;margin:20px auto;padding:28px;border:1px solid #e1e7ef;border-radius:14px;background:#fff}.login-card h1{margin-top:0}.login-form{display:flex;flex-direction:column;gap:10px}.login-form input{width:100%;border:1px solid #d4ddea;border-radius:8px;padding:10px 12px}.login-form button[type=submit]{margin-top:12px;background:#235bd8;color:#fff}.login-error{color:#b42318;margin:0}.login-back{display:inline-block;margin-top:20px}.brand{flex-shrink:0;font-size:25px;font-weight:800;letter-spacing:-1px;color:#1e3450}.brand span{color:var(--blue);font-style:italic;margin-right:2px}.site-header nav{display:flex;gap:24px;align-self:stretch;align-items:center}.prep-goal-label{flex-shrink:0}.prep-goal-label select{border:1px solid #d9e1ed;border-radius:8px;background:#f7f9fc;color:#24426b;padding:9px 12px;font-size:13px;font-weight:600;cursor:pointer}.site-header nav a{padding:24px 0 21px;border-bottom:3px solid transparent;color:#607089;font-size:14px;font-weight:600;white-space:nowrap}.site-header nav a.active{color:var(--blue);border-bottom-color:var(--blue)}main{max-width:var(--site-width);margin:0 auto;padding:26px 30px 48px;min-height:75vh}main:has(.practice-blocks),main:has(.question-content),main:has(.paper-blocks){max-width:1120px}footer{text-align:center;color:#8491a5;font-size:13px;padding:25px}.page-heading{display:flex;align-items:center;justify-content:space-between;gap:20px;margin:0 0 25px}.page-heading h1{font-size:30px;line-height:1.4;margin:8px 0}.eyebrow{font-size:12px;letter-spacing:0;font-weight:600;color:#53729b;margin:0}.muted{color:var(--muted);font-size:13px}.page-heading p.muted{font-size:15px;margin:0}.count{color:#55708e;font-size:14px}.filters{display:flex;gap:12px;margin-bottom:26px}.filters input,.filters select{padding:11px 14px;background:#fff;border:1px solid #d9e1ed;border-radius:9px;min-width:0}.filters input{width:100%}.search-label{flex:1}.filters button{background:#2c62d7;color:#fff;border-color:#2c62d7}.catalog{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px}.catalog-card{display:flex;flex-direction:column;gap:18px;min-height:172px;padding:24px;border:1px solid #e0e6ef;border-radius:14px;background:#fff;color:inherit;transition:box-shadow .15s,border-color .15s}.catalog-card:hover{box-shadow:0 7px 20px #2748750d;border-color:#b2c8ef}.catalog-card>div{display:flex;gap:10px;align-items:center;flex-wrap:wrap}.catalog-card h2{font-size:17px;line-height:1.6;margin:0;font-weight:600}.card-action{color:#4775c5;font-size:13px;margin-top:auto;display:flex;justify-content:space-between}.badge{font-size:12px;color:#3d68ad;background:#edf3ff;padding:3px 9px;border-radius:6px}.button-link{display:inline-block;padding:8px 16px;border:1px solid #c7d6ef;border-radius:8px;font-size:14px}.catalog-filters{flex-wrap:wrap}.catalog-filters label{display:flex;align-items:center;gap:10px}.pagination{display:flex;justify-content:center;align-items:center;gap:20px;margin:32px 0;font-size:14px}.status{padding:50px;text-align:center;color:#6a7f9c}.error{background:#fff0ed;border:1px solid #f2c4b9;padding:20px;border-radius:12px;color:#943c29}.detail-toolbar{display:flex;justify-content:space-between;align-items:center;margin-bottom:24px;font-size:14px}.panel{padding:30px;background:#fff;border:1px solid #e0e6ef;border-radius:15px;margin:20px 0}.question-heading{display:flex;align-items:center;gap:12px;margin-bottom:20px}.item-label{font-weight:700;color:#29476c;flex-shrink:0}.markdown{overflow-wrap:anywhere;font-size:15px}.markdown>:first-child{margin-top:0}.markdown p{margin:1em 0}.markdown img{max-width:100%;height:auto;display:block;margin:22px auto}.markdown h1{font-size:24px}.markdown h2{font-size:20px;border-bottom:1px solid #edf0f5;padding-bottom:8px;margin-top:28px}.markdown h3{font-size:17px}.markdown a{overflow-wrap:anywhere}.markdown .katex-display{overflow-x:auto;overflow-y:hidden;padding:5px 0}.markdown table{border-collapse:collapse;margin:20px 0;display:block;overflow-x:auto;width:max-content;max-width:100%}.markdown td,.markdown th{border:1px solid #dbe3ef;padding:8px 13px;text-align:left}.markdown th{background:#f4f7fc}.markdown pre{overflow:auto;background:#f6f8fc;border:1px solid #e5eaf2;border-radius:8px;padding:15px;margin:20px 0;line-height:1.8;font-size:13px}.markdown code{font-family:Consolas,Courier New,monospace}.markdown :not(pre)>code{background:#f0f4fa;border-radius:4px;padding:2px 5px;color:#254876}.code-line{display:flex;min-height:1.8em;white-space:pre}.code-number{color:#93a1b7;min-width:35px;margin-right:15px;border-right:1px solid #e0e7f1;-webkit-user-select:none;user-select:none}.choices{padding:0;list-style:none;display:grid;gap:10px;margin:22px 0}.choices li{display:flex;align-items:flex-start;gap:18px;border:1px solid #e1e7f0;padding:12px 16px;border-radius:9px}.choices li>b{color:#406ba8}.markdown.inline{display:inline-block}.markdown.inline>p{margin:0}.child-question{border-top:1px solid #e3e9f2;margin-top:30px;padding-top:25px;scroll-margin-top:20px}.child-question.focused{outline:2px solid #bbd2fa;outline-offset:12px;border-radius:8px}.solution,.sources{border:1px solid #e0e7f2;border-radius:9px;margin:16px 0;background:#fafcff}.solution summary,.sources summary{cursor:pointer;padding:12px 16px;color:#3a5e94;font-size:14px}.solution-body{padding:8px 20px 20px}.sources ul{margin:0;padding:8px 35px 20px}.sources li{margin:8px 0;font-size:13px}.sources small{display:block;color:#8794a5}.sources p{margin:5px 0}.sample-files{display:flex;gap:12px;flex-wrap:wrap;font-size:13px;margin:20px 0}.sample-files>span{color:#76869b}.paper-blocks{display:flex;flex-direction:column;gap:12px}.paper-question{display:flex;align-items:center;gap:20px;padding:20px 24px;background:#fff;border:1px solid #e0e6ef;border-radius:12px;color:inherit}.paper-question>div{flex:1;min-width:0}.paper-question h2{font-size:16px;margin:0 0 5px}.paper-question:hover{border-color:#9bb9ec}.paper-question .score{font-size:13px;color:#6e819c}.paper-content{padding:18px 24px;background:#fff;border-radius:12px}.paper-content.section{border-left:3px solid #5b81c7}.subitem-scores{display:flex;flex-wrap:wrap;gap:10px;margin-top:8px;font-size:12px;color:#7387a1}.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}@media(max-width:850px){.catalog{grid-template-columns:repeat(2,minmax(0,1fr))}.site-header-inner{flex-wrap:wrap;gap:12px 24px;padding-top:14px}.site-header nav{order:1;flex-basis:100%;gap:24px;overflow-x:auto}.site-header nav a{padding:8px 0 11px}}@media(max-width:560px){main{padding:24px 16px 40px}.site-header-inner{padding-left:16px;padding-right:16px;gap:10px 16px}.site-header nav{gap:18px}.site-header nav a{font-size:13px}.brand{font-size:22px}.prep-goal-label select{padding:7px 8px;font-size:12px}.catalog{grid-template-columns:1fr}.filters{flex-wrap:wrap}.search-label{flex-basis:100%}.filters select{flex:1}.page-heading h1{font-size:24px}.panel{padding:20px 16px}.paper-question{padding:16px;gap:12px;align-items:flex-start}.count{white-space:nowrap}.code-number{min-width:25px;margin-right:10px}}@media print{body{background:#fff}.site-header,footer,.detail-toolbar,.filters,.pagination,.sources,.solution{display:none}.panel{border:0;padding:0}main{max-width:none;padding:0}main:has(.practice-blocks),main:has(.question-content),main:has(.paper-blocks){max-width:none}.child-question{break-inside:avoid}.markdown pre{white-space:pre-wrap}.paper-question,.catalog-card{break-inside:avoid}}.topics-layout{display:grid;grid-template-columns:294px minmax(0,1fr);gap:22px;align-items:start}.topics-sidebar{min-width:0;position:sticky;top:98px;max-height:calc(100vh - 122px);overflow:auto;scrollbar-gutter:stable;overscroll-behavior:contain;border:1px solid var(--line);border-radius:18px;background:#fff;padding:24px;box-shadow:0 10px 34px #1d32520b}.tree-heading{padding:0}.tree-heading h2{margin:7px 0;font-size:22px;line-height:normal}.tree-heading p{margin:0;font-size:12px}.tree-heading .eyebrow{color:#1d4fbd;font-weight:700;font-size:11px}.tree-heading-actions{display:flex;align-items:center;justify-content:space-between;gap:12px;margin:22px 0 9px}.topic-heading>span{color:#78869a;font-size:12px;font-weight:850}.topic-heading>span b{margin-left:6px;color:var(--blue);font-size:10px}.tree-multi{padding:5px 7px;border-radius:8px;font-size:10px;font-weight:850;color:#63748a}.tree-multi[aria-pressed=true]{background:#eaf1ff;border-color:#c8dafc;color:#1d4fbd}.tree-point-label{display:flex;align-items:center;gap:8px;min-width:0}.tree-level-tag{display:inline-block;margin-left:6px;padding:1px 5px;border-radius:5px;background:#f3e8ff;color:#7c3aad;font-size:10px;font-style:normal;font-weight:800;vertical-align:1px}.tree-check{display:grid;place-items:center;flex:0 0 14px;height:14px;border:1px solid #c7d3e3;border-radius:3px;background:#fff;font-size:11px;line-height:1}.tree-check.checked{background:var(--blue);border-color:var(--blue);color:#fff}.tree-link{display:flex;align-items:center;justify-content:space-between;gap:10px;padding:8px 9px;border-radius:8px;font-size:13px;color:var(--ink);line-height:normal}.tree-link:hover{background:#f3f7ff}.tree-link.selected{background:#eaf1ff;color:#1d4fbd;font-weight:850}.tree-link.empty{color:var(--ink)}.tree-count{display:inline-flex;flex:0 0 auto;align-items:baseline;gap:3px;white-space:nowrap;font-size:10px;font-weight:750;color:#93a0b1;font-variant-numeric:tabular-nums}.tree-count b{color:#3b9a7b;font-size:11px}.tree-chapter{border-top:1px solid #edf0f5;margin-top:13px;padding-top:13px}.tree-chapter h3{margin:0 0 7px;font-size:11px;font-weight:800;color:#8a96a7}.tree-empty{font-size:13px;color:var(--muted)}.topics-results{min-width:0}.topic-empty{padding:50px 24px;min-height:240px;display:grid;place-content:center;justify-items:center;gap:12px;text-align:center}.topic-empty strong{font-size:18px}.topic-empty span{color:var(--muted);font-size:13px}.topics-panel{position:relative;background:#fff;border:1px solid var(--line);border-radius:18px;overflow:hidden;box-shadow:0 10px 34px #1d32520b}.topic-updating{position:absolute;right:24px;z-index:1;margin:3px 0 0;padding:3px 9px;border-radius:6px;background:#edf3ff;color:#3267c7;font-size:12px}.topics-panel[aria-busy=true] .topic-question-list{opacity:.6}.wrong-book-panel{--topic-actions-width: 120px}.topic-filters{padding:22px 24px 18px;background:#f9fbfe;border-bottom:1px solid var(--line)}.topic-filter-fields{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:20px}.topic-type-filter{display:grid;gap:7px;min-width:0}.topic-type-filter>span{color:#63748a;font-size:12px;font-weight:700}.topic-filters select,.topic-filters input[type=search]{width:100%;min-width:0;height:40px;padding:8px 10px;border:1px solid #dce5f0;border-radius:8px;background:#fff;color:var(--ink);font-size:13px}.topic-filters select:disabled{color:#8090a5}.topic-filter-secondary{display:flex;justify-content:space-between;align-items:center;flex-wrap:wrap;gap:16px;margin-top:16px}.topic-filter-toggles{display:flex;align-items:center;flex-wrap:wrap;gap:14px 20px}.topic-filter-toggles label{display:inline-flex;gap:8px;align-items:center;font-size:12px;color:#53657d;cursor:pointer;white-space:nowrap}.topic-filter-toggles input{width:15px;height:15px;margin:0;accent-color:var(--blue)}.topic-filter-search{display:flex;gap:6px;margin-left:auto;flex:0 1 280px;min-width:0}.topic-filter-search .search-label{position:relative;min-width:0}.topic-filter-search svg{width:16px;height:16px}.topic-filter-search .search-label svg{position:absolute;left:10px;top:9px;color:#8290a3;pointer-events:none}.topic-filter-search input[type=search]{height:34px;padding:7px 10px 7px 33px;background:transparent;font-size:12px}.topic-filter-search input:focus{background:#fff}.topic-filter-search input::placeholder{color:#77869b}.topic-filter-search button{display:inline-flex;align-items:center;justify-content:center;padding:6px 9px;flex-shrink:0;font-size:12px}.topic-filter-search button[type=submit]{background:#edf3ff;border-color:#dce5f0;color:#2f6fed}.topic-filter-search .filter-reset{border-color:transparent;color:#63748a;background:transparent}.difficulty-filter{display:flex;flex-wrap:wrap;gap:8px}.difficulty-filter button{font-size:12px;border-radius:20px;padding:5px 13px}.difficulty-filter button[aria-pressed=true]{color:#fff;background:var(--blue);border-color:var(--blue)}.difficulty-filter small{margin-left:5px}.topic-results-heading{min-height:66px;padding:11px 22px;border-bottom:1px solid var(--line)}.topic-summary-line{display:flex;align-items:center;justify-content:space-between;gap:12px;min-width:0}.topic-summary-title{display:flex;align-items:center;gap:10px;min-width:0;flex-wrap:wrap}.topic-summary-actions{display:flex;align-items:center;gap:7px;flex-shrink:0}.topic-summary-actions button{padding:10px 15px;font-size:12px;font-weight:800;border:1px solid var(--line);border-radius:9px;background:#fff;color:#1d4fbd}.topic-summary-actions .practice-print-control button{background:var(--blue);color:#fff}.topic-summary-actions{flex-wrap:wrap}.topic-shuffle{color:var(--ink);font-weight:650}.topic-summary-label{flex-shrink:0;font-size:11px;color:#78869a}.topic-shuffle{display:inline-flex;align-items:center;gap:6px;flex-shrink:0;font-size:12px;color:#53657d;cursor:pointer}.topic-shuffle input{appearance:none;position:relative;width:32px;height:19px;border:0;border-radius:20px;background:#c7d0dd;margin:0}.topic-shuffle input:before{content:"";position:absolute;width:13px;height:13px;left:3px;top:3px;border-radius:50%;background:#fff;transition:transform .15s}.topic-shuffle input:checked{background:var(--blue)}.topic-shuffle input:checked:before{transform:translate(13px)}.topic-filter-chips{display:flex;flex-wrap:wrap;gap:6px;min-width:0;align-items:center}.topic-filter-chip{display:inline-flex;align-items:center;gap:3px;max-width:100%;padding:5px 8px;border-radius:999px;border:1px solid #d6e3fb;background:#f2f6ff;color:#42649b;font-size:10px;text-align:left;overflow-wrap:anywhere}.topic-filter-chip:hover{background:#e7effd;border-color:#b9cef0}.topic-filter-chip span{font-size:10px;line-height:normal}.topic-results-heading h1{font-size:14px;margin:0;line-height:1.6;font-weight:600}.topic-goal-badge{flex-shrink:0;border-radius:20px;border:1px solid #d6e3fb;background:#f2f6ff;color:#42649b;padding:5px 8px;font-size:10px}.topic-results-heading .count{font-size:12px;color:var(--ink);white-space:nowrap;flex-shrink:0}.topic-list-columns,.topic-question-row{display:grid;grid-template-columns:36px 112px minmax(0,1fr) 144px;gap:14px;padding:17px 25px;align-items:center}.topic-question-group>summary{list-style:none;cursor:pointer}.topic-question-group>summary::-webkit-details-marker{display:none}.topic-question-group>summary:focus-visible{outline:2px solid var(--blue);outline-offset:-3px}.topic-group-toggle{position:relative;z-index:2;grid-column:5;grid-row:1;justify-self:end;display:inline-flex;align-items:center;justify-content:center;gap:8px;min-width:96px;min-height:28px;border-radius:4px;color:#6b7e99}.topic-group-progress{display:grid;justify-items:end;color:#1d4fbd;font-size:13px;white-space:nowrap}.topic-group-progress small{margin-top:3px;color:#8390a2;font-size:10px;font-weight:700}.topic-question-group>.topic-question-row{grid-template-columns:36px 112px minmax(0,1fr) 100px 112px}.topic-group-toggle:hover{background:#eaf2ff}.topic-group-chevron{width:16px;height:16px}.topic-question-group[open] .topic-group-chevron{transform:rotate(180deg)}.topic-group-children{margin:0 24px 16px 48px;background:#fff;border:1px solid #e0e7f1;border-radius:11px;overflow:hidden}.topic-question-group{background:#f7faff;border-bottom:1px solid #e0e7f1}.topic-question-group>summary{border-bottom:0}.topic-child-row .topic-question-info h2{font-size:13px;font-weight:500}.topic-list-columns{font-size:11px;color:#8291a8;background:#f9fbfe;padding-top:14px;padding-bottom:14px;border-bottom:1px solid var(--line)}.topic-question-row{position:relative;min-height:73px;border-bottom:1px solid #e7edf5;transition:background .15s}.topic-row-link{position:absolute;inset:0;z-index:1;border-radius:6px}.topic-row-actions{position:relative;z-index:2;grid-column:5}.wrong-book-panel .topic-question-row,.wrong-book-panel .topic-list-columns{grid-template-columns:36px 112px minmax(0,1fr) 144px}.topic-question-row:last-child{border-bottom:0}.topic-question-row:hover,.topic-question-row:focus-within{background:#f6f9ff}.topic-progress{display:grid;place-items:center;width:22px;height:22px;border:1px solid #d4dfef;border-radius:50%}.topic-progress svg{width:18px;height:18px}.topic-progress.done{background:#1fa370;border-color:#1fa370;color:#fff}.topic-progress.wrong{background:#e15b5b;border-color:#e15b5b;color:#fff}.topic-question-origin{display:grid;gap:4px;min-width:0}.topic-year{color:var(--blue);font-size:16px;line-height:normal;font-weight:700;font-variant-numeric:tabular-nums}.topic-question-origin .muted{font-size:11px}.topic-question-info{min-width:0;overflow-wrap:anywhere}.topic-question-info h2{font-size:14px;line-height:normal;margin:0 0 4px;font-weight:700}.topic-question-info h2 a{color:var(--ink)}.topic-question-info h2 a:hover{color:var(--blue)}.topic-question-meta{display:flex;flex-wrap:wrap;color:#8291a8;font-size:11px;gap:0 6px}.topic-question-meta>span+span:before{content:"·";margin-right:6px}.topic-question-meta .topic-state-review{color:#98601a}.topic-question-tags{display:flex;flex-wrap:wrap;gap:5px;min-width:0}.topic-question-tags .badge{font-size:11px;border-radius:20px;overflow-wrap:anywhere}.topic-practice-link{font-size:12px;white-space:nowrap;justify-self:end}.context-links{display:grid;gap:8px}.topic-row-actions{display:flex;align-items:center;justify-content:flex-end;flex-wrap:wrap;gap:8px}.context-links .topic-practice-link{white-space:normal}.topics-panel .pagination{margin:0;padding:24px;border-top:1px solid var(--line)}.topics-panel .status{margin:0}.topics-panel .error{margin:16px 24px}@media(max-width:1200px){.topics-layout{grid-template-columns:264px minmax(0,1fr);gap:18px}.topic-list-columns,.topic-question-row{grid-template-columns:26px 74px minmax(0,1fr) 100px 32px;gap:12px;padding-left:20px;padding-right:20px}.topic-row-actions{grid-column:5;justify-self:end}.wrong-book-panel .topic-question-row,.wrong-book-panel .topic-list-columns{grid-template-columns:26px 74px minmax(0,1fr) 100px 32px}.topic-filter-fields{gap:12px}}@media(max-width:850px){.topics-layout{grid-template-columns:220px minmax(0,1fr);gap:14px}.topics-sidebar{padding:20px 12px;top:132px;max-height:calc(100vh - 150px)}.topic-list-columns,.topic-question-row,.wrong-book-panel .topic-question-row,.wrong-book-panel .topic-list-columns{grid-template-columns:24px 66px minmax(0,1fr) 32px}.topic-group-toggle,.topic-row-actions{grid-column:4}.topic-list-columns>:nth-child(4),.topic-question-tags{display:none}.topic-filter-fields{gap:10px}.topic-filters{padding:18px 16px}}@media(max-width:700px){.topics-layout{display:flex;flex-direction:column;gap:16px}.topics-sidebar{width:100%;position:static;max-height:260px;padding:18px 16px;border-radius:14px}.tree-heading{padding-bottom:14px}.tree-heading h2{font-size:18px}.topics-results{width:100%}.topics-panel{border-radius:14px}.topic-filter-fields{grid-template-columns:repeat(2,minmax(0,1fr));gap:14px}.topic-type-filter:first-child{grid-column:1 / -1}.topic-filter-search{flex-basis:100%}.topic-filter-search .search-label{flex-basis:auto}.topic-results-heading{padding:14px 16px}.topic-summary-title{gap:4px 8px;flex-wrap:wrap}.topic-summary-line{flex-wrap:wrap}.topic-shuffle{margin-left:auto}.topic-results-heading h1{font-size:13px}.topic-list-columns{display:none}.topic-question-row{grid-template-columns:22px minmax(0,1fr);gap:5px 12px;padding:16px}.wrong-book-panel .topic-question-row{grid-template-columns:22px minmax(0,1fr)}.topic-progress{grid-row:1 / 4;align-self:start;margin-top:2px}.topic-question-origin{display:flex;align-items:center;gap:8px}.topic-year{font-size:13px}.topic-question-info,.topic-question-tags,.topic-group-toggle,.topic-row-actions{grid-column:2}.topic-question-tags{display:flex;margin-top:3px}.topic-group-toggle{position:absolute;right:12px;top:10px;width:32px;height:32px}.topic-question-group>summary .topic-question-origin{padding-right:32px}.topic-group-children{margin:0 8px 12px 24px}}@media print{.topics-sidebar,.topic-filters,.topic-practice-link{display:none}.topics-layout{display:block}}.topic-child-row,.wrong-book-panel .topic-child-row{grid-template-columns:20px 68px minmax(0,1fr) 140px;gap:10px;min-height:48px;padding:8px 14px}.wrong-book-panel .topic-child-row{grid-template-columns:20px 68px minmax(0,1fr) 110px 28px}.topic-child-row .topic-progress{width:18px;height:18px;grid-row:auto;align-self:center;margin:0;font-size:12px;line-height:1}.topic-child-row .topic-question-origin{white-space:nowrap}.topic-child-row .topic-question-info h2{margin:0;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.topic-child-row .topic-question-tags{flex-wrap:nowrap;overflow:hidden}.topic-child-row .topic-question-tags .badge{padding:0;border:0;background:none;color:#78869a;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}@media(max-width:850px){.topic-child-row,.wrong-book-panel .topic-child-row{grid-template-columns:18px 56px minmax(0,1fr);gap:8px;padding:8px 10px}.wrong-book-panel .topic-child-row{grid-template-columns:18px 56px minmax(0,1fr) 28px}.topic-child-row .topic-question-info{grid-column:3}.topic-child-row .topic-row-actions{grid-column:4}.topic-child-row .topic-question-tags{display:none}}@media(max-width:700px){.topic-summary-actions{margin-left:auto}}.topic-select{position:absolute;left:8px;top:50%;transform:translateY(-50%);z-index:4;width:18px;height:18px}.topic-question-row:has(.topic-select){padding-left:38px}.program-status-label{font-size:12px;color:#397059}.topics-layout .topic-question-info h2{white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.topics-layout .topic-question-tags .badge{border:0;background:#edf4ff;color:#2c61c5;border-radius:999px;padding:6px 9px;font-size:11px;font-weight:850}.topics-layout .topic-child-row .topic-question-tags .badge{border:0;padding:0;background:transparent}.topics-layout .topic-question-row:has(.topic-select){padding-left:25px}.topics-layout .topic-select{left:25px;width:22px;height:22px}.topics-layout .topic-question-row:has(.topic-select)>.topic-progress{visibility:hidden}.topics-layout .wrong-book-panel .topic-question-group>.topic-question-row{grid-template-columns:36px 112px minmax(0,1fr) 100px 112px}.topics-layout .topic-child-row,.topics-layout .wrong-book-panel .topic-child-row{grid-template-columns:20px 88px minmax(0,1fr) 140px}@media(max-width:1200px){.topics-layout{grid-template-columns:250px minmax(0,1fr);gap:22px}.topics-layout .topic-question-row,.topics-layout .topic-list-columns,.topics-layout .wrong-book-panel .topic-question-row,.topics-layout .wrong-book-panel .topic-list-columns{grid-template-columns:28px 86px minmax(0,1fr);padding:17px 25px}.topics-layout .topic-question-group>.topic-question-row,.topics-layout .wrong-book-panel .topic-question-group>.topic-question-row{grid-template-columns:28px 86px minmax(0,1fr) 100px}.topics-layout .topic-group-toggle{grid-column:4}.topics-layout .topic-list-columns>:nth-child(4),.topics-layout .topic-question-tags{display:none}.topics-layout .topic-child-row,.topics-layout .wrong-book-panel .topic-child-row{grid-template-columns:20px 88px minmax(0,1fr);padding:9px 14px}}@media(max-width:700px){.topics-layout{display:grid;grid-template-columns:minmax(0,1fr);gap:22px}.topics-layout .topics-sidebar{max-height:none;overflow:visible;padding:24px;scrollbar-gutter:auto;border-radius:18px}.topics-layout .knowledge-tree{max-height:none;overflow:visible}.topics-layout .topic-tree-chapters{max-height:340px;overflow:auto}.topics-layout .tree-heading{padding-bottom:0}.topics-layout .tree-heading h2{font-size:22px}.topics-layout .topic-question-row,.topics-layout .wrong-book-panel .topic-question-row{grid-template-columns:25px 72px minmax(0,1fr);gap:14px;padding:15px}.topics-layout .topic-question-origin{display:grid;gap:4px}.topics-layout .topic-progress{grid-row:auto;align-self:center;margin:0}.topics-layout .topic-question-info{grid-column:3}.topics-layout .topic-year{font-size:16px}.topics-layout .topic-question-origin .muted{overflow:hidden;white-space:nowrap;text-overflow:ellipsis}.topics-layout .topic-question-group>.topic-question-row,.topics-layout .wrong-book-panel .topic-question-group>.topic-question-row{grid-template-columns:25px 58px minmax(0,1fr) 26px;gap:8px}.topics-layout .topic-group-toggle{position:relative;grid-column:4;top:auto;right:auto;width:26px;min-width:26px;height:28px}.topics-layout .topic-group-progress{display:none}.topics-layout .topic-question-group>summary .topic-question-origin{padding-right:0}.topics-layout .topic-child-row,.topics-layout .wrong-book-panel .topic-child-row{grid-template-columns:18px 56px minmax(0,1fr);gap:8px;padding:9px 10px}.topics-layout .topic-select{left:15px}.topics-layout .topic-question-row:has(.topic-select){padding-left:15px}.topics-layout .topic-child-row .topic-select{left:10px;width:18px;height:18px}}.visually-hidden{position:absolute;width:1px;height:1px;padding:0;overflow:hidden;clip-path:inset(50%);white-space:nowrap}main:has(.question-practice-layout){max-width:var(--site-width)}.question-practice-layout{display:grid;grid-template-columns:minmax(0,1fr) 300px;gap:24px;align-items:start}.question-practice-card{background:#fff;border:1px solid var(--line);border-radius:16px;padding:26px 30px;min-width:0}.question-practice-card .question-return-toolbar button{padding:5px 10px;font-size:12px}.practice-detail-heading .origin-paper{font-size:12px;margin-bottom:16px}.question-practice-card .paper-content{border:0;padding:0;background:transparent}.question-practice-card .practice-blocks{gap:24px}.question-practice-card .markdown pre{font-size:15px;line-height:1.75}.shared-question-layout{display:grid;grid-template-columns:minmax(0,1fr);gap:20px;align-items:start}.shared-material,.shared-answer-panel{min-width:0}.shared-answer-panel{scroll-margin-top:20px}.subquestion-navigation{margin-bottom:12px}.question-practice-card .current-subquestion{padding:16px;border:1px solid var(--line);border-radius:10px}.current-subquestion>.practice-question>.question-heading{background:#f5f8fc;margin:-16px -16px 16px;padding:10px 16px;border-bottom:1px solid var(--line);border-radius:10px 10px 0 0}.subquestion-navigation p{color:var(--muted);font-size:12px;margin:0 0 10px}.subquestion-navigation>div{display:flex;flex-wrap:wrap;gap:8px}.subquestion-navigation a{padding:8px 12px;border:1px solid var(--line);border-radius:8px;color:var(--ink);font-size:13px;text-decoration:none}.subquestion-navigation a.done{background:#edf8f1;border-color:#b8dfc7}.subquestion-navigation a.wrong{background:#fff1f1;border-color:#f2c6c6}.subquestion-navigation a[aria-current=page]{color:var(--blue);border-color:var(--blue);box-shadow:inset 0 0 0 1px var(--blue)}@media print{.shared-question-layout{display:block}.shared-answer-panel{position:static}.subquestion-navigation{display:none}}.question-answer-actions{display:flex;align-items:center;flex-wrap:wrap;gap:10px;margin:16px 0 12px}.question-answer-actions button{font-size:13px;padding:9px 16px}.question-answer-actions .answer-submit{color:#fff;background:var(--blue);border-color:var(--blue)}.question-answer-actions .wrong-book-control{margin:0}.question-verdict{padding:12px 16px;background:#fff5ed;border-radius:8px;color:#92552c}.question-verdict.correct{color:#247553;background:#eff9f3}.verdict-hint{display:inline-block;margin-left:12px;font-size:12px;color:var(--muted)}.question-explanation h3{margin:0 0 12px;font-size:14px}.question-explanation{margin:20px 0;padding:20px;background:#f8faff;border:1px solid var(--line);border-radius:10px}.question-explanation .solution{background:transparent;border:0;margin:0}.draft-status{font-size:12px;color:var(--muted)}.practice-question-nav{display:flex;justify-content:space-between;align-items:center;gap:12px;border-top:1px solid var(--line);padding-top:22px;margin-top:30px}.practice-question-nav span{color:var(--muted);font-size:12px;text-align:center}.practice-question-nav small{display:block;font-size:11px;color:#8c99aa}.related-practice{position:sticky;top:98px;min-width:0;background:#fff;padding:22px;border:1px solid var(--line);border-radius:16px}.related-practice h2{font-size:17px;margin:8px 0}.related-practice .muted{font-size:12px}.related-question{display:block;padding:14px 0;border-bottom:1px solid #edf1f7;color:var(--ink)}.related-question:hover{color:var(--blue)}.related-question strong{display:block;font-size:13px;font-weight:500;overflow-wrap:anywhere}.related-question span{display:block;font-size:11px;color:var(--muted);margin-top:5px}.related-all{display:block;font-size:12px;margin-top:18px}.archive-group{margin:0 0 32px}.archive-group h2{font-size:17px;margin:0 0 12px}.archive-years{display:grid;grid-template-columns:repeat(auto-fill,minmax(190px,1fr));gap:14px}.archive-year-card{display:flex;flex-direction:row;align-items:center;gap:14px;min-height:86px;padding:20px;border-radius:12px}.archive-year-card svg{width:20px;height:20px;flex-shrink:0;color:#6984ac}.archive-year-card strong{font-size:20px;color:var(--ink)}.archive-year-card>span{margin-left:auto;color:#8a9cb5}@media(max-width:1000px){.question-practice-layout{grid-template-columns:minmax(0,1fr) 250px;gap:16px}.question-practice-card{padding:22px}}@media(max-width:700px){.question-practice-layout{grid-template-columns:minmax(0,1fr)}.question-practice-card{padding:18px 16px}.related-practice{position:static}.practice-question-nav button{padding:8px 10px;font-size:12px}.question-explanation{padding:14px}.archive-years{grid-template-columns:repeat(2,minmax(0,1fr));gap:10px}.archive-year-card{padding:16px 12px;gap:10px}}@media print{.related-practice,.practice-question-nav,.question-answer-actions,.question-explanation,.question-verdict,.draft-status{display:none}.question-practice-layout{display:block}.question-practice-card{border:0;padding:0}}.practice-blocks{display:grid;grid-template-columns:minmax(0,1fr);gap:18px}.practice-panel{min-width:0}.practice-question .question-heading{flex-wrap:wrap}.practice-question .child-question{padding-top:24px;margin-top:28px}.practice-note{padding:12px 16px;background:#edf2fa;border-radius:8px;font-size:13px;color:#5a7192}.answer-input{padding:0;border:0;margin:20px 0;min-width:0}.answer-options{display:grid;gap:10px}.answer-options label{display:flex;align-items:baseline;gap:12px;padding:13px 16px;border:1px solid #dfe6ef;border-radius:9px;cursor:pointer;min-width:0}.answer-options label.selected{border-color:#6891e1;background:#eef4ff}.answer-options input{flex-shrink:0;accent-color:#2d65d7}.answer-options .markdown{min-width:0}.boolean-options{grid-template-columns:repeat(2,minmax(0,1fr))}.blank-input{display:grid;gap:8px;margin:16px 0}.blank-input textarea{resize:vertical;width:100%;font:inherit;padding:12px;border:1px solid #ced9e8;border-radius:8px}.answer-result{border-left:4px solid #d49664;background:#fff7ed;padding:16px 20px;margin:20px 0;border-radius:4px;overflow-wrap:anywhere}.answer-result.correct{border-color:#43a582;background:#f0faf5}.answer-result.unavailable{border-color:#92a0b2;background:#f4f6f9}.answer-result p{margin:8px 0;white-space:pre-wrap}.grade-summary{padding:26px;background:#eef4ff;border:1px solid #cddcf6;border-radius:14px;margin:24px 0}.grade-summary h2{font-size:18px;margin-top:0}.grade-number{font-size:26px;color:#285fb8}.practice-submit{position:sticky;bottom:16px;display:flex;align-items:center;justify-content:space-between;gap:16px;padding:14px 20px;background:#fff;border:1px solid #d1dded;box-shadow:0 4px 24px #31486714;border-radius:12px;margin-top:26px;z-index:2}.practice-submit button{color:#fff;background:#2c62d7;border-color:#2c62d7}.practice-submit span{color:#5e7494;font-size:14px}@media(max-width:700px){.practice-submit{bottom:8px;padding:12px}.practice-submit button{padding:8px 12px}}@media print{.answer-result,.practice-submit,.practice-note,.grade-summary{display:none}.practice-blocks{display:block}.practice-panel{margin-bottom:20px}.answer-options input,.blank-input textarea{display:none}.answer-options label.selected{background:none;border-color:#dfe6ef}.blank-input:after{content:"________________________________"}}main:has(>.topics-layout),main:has(>.question-practice-layout){width:min(1380px,calc(100% - 36px));max-width:1380px;margin:26px auto 64px;padding:0}.question-practice-layout{grid-template-columns:minmax(0,1fr) 292px;gap:22px}.question-practice-layout .question-practice-card{padding:30px;border-radius:18px;box-shadow:0 10px 34px #1d32520b}.question-practice-layout .question-return-toolbar .practice-print-control button{border:0;border-radius:9px;padding:9px 13px;background:#eff4fb;color:var(--blue);font-size:13px;font-weight:650;box-shadow:none}.question-practice-layout .program-group-title{margin:12px 0 22px;display:flex}.question-practice-layout .program-group-title>strong{border-radius:999px;padding:8px 12px;background:#edf4ff;color:#1d4fbd;font-size:12px}.question-practice-layout .question-text-panel{border:1px solid var(--line);border-radius:14px;overflow:hidden;background:#fbfcfe}.question-practice-layout .question-text-panel>.markdown{padding:24px;font-size:16px;line-height:1.75;color:#334257}.question-practice-layout .question-text-panel p:last-child{margin-bottom:0}.question-practice-layout .question-text-panel .markdown pre{margin:14px 0;padding:0;border:0;background:#fbfcfe;font:14px/1.65 Consolas,monospace}.question-practice-layout .shared-material .paper-content{margin:0;padding:0}.question-practice-layout .shared-material .paper-content .markdown{padding:24px;font-size:16px}.question-practice-layout .shared-material .paper-content .markdown pre{font-size:14px}.question-practice-layout .question-text-panel .answer-input{margin:0}.question-practice-layout .answer-options{padding:0 24px 24px;background:#fbfcfe}.question-practice-layout .answer-options label{display:grid;grid-template-columns:36px minmax(0,1fr);align-items:start;gap:12px;border:1px solid #dfe5ee;border-radius:11px;padding:13px 15px;background:#fff;transition:border-color .16s,background .16s,box-shadow .16s}.question-practice-layout .answer-options label:hover{border-color:#9cbaf6;background:#f6f9ff}.question-practice-layout .answer-options label.selected{border-color:var(--blue);background:#edf4ff;box-shadow:0 0 0 2px #2f6fed17}.question-practice-layout .answer-options input{position:absolute;opacity:0;width:1px;height:1px}.question-practice-layout .answer-options label:has(input:focus-visible){outline:2px solid var(--blue);outline-offset:3px}.question-practice-layout .answer-options label>b{width:30px;height:30px;display:grid;place-items:center;border-radius:8px;background:#edf1f6;color:#102d50}.question-practice-layout .answer-options label.selected>b{background:var(--blue);color:#fff}.question-practice-layout .answer-options label>.markdown{padding-top:4px;color:#334257;line-height:1.65;font-size:16px;white-space:pre-wrap}.question-practice-layout .boolean-options label{align-items:center}.question-practice-layout .answer-box{border:1px solid var(--line);border-radius:14px;margin-top:20px}.question-practice-layout .answer-box .blank-input{margin:20px}.question-practice-layout .answer-box textarea{font-family:Consolas,Microsoft YaHei UI,monospace}.question-practice-layout .question-answer-actions{padding:20px;margin:0;gap:10px}.question-practice-layout .question-answer-actions button{padding:10px 16px;border-radius:9px;font-size:13px;font-weight:850}.question-practice-layout .answer-reveal:after{content:"";display:inline-block;width:6px;height:6px;margin-left:9px;margin-bottom:3px;border-right:2px solid currentColor;border-bottom:2px solid currentColor;transform:rotate(45deg)}.question-practice-layout .answer-reveal[aria-expanded=true]:after{transform:rotate(225deg);margin-bottom:0}.question-practice-layout .wrong-book-control{display:inline-flex;gap:4px;align-items:center;flex-wrap:wrap}.question-practice-layout .wrong-book-control button[aria-pressed=true]{opacity:1;color:#475569;background:#f1f5f9;border-color:#e2e8f0}.question-practice-layout .wrong-book-control .detail-wrong-remove{border:0;background:transparent;color:#64748b;padding-left:6px;padding-right:6px;font-weight:500;text-decoration:underline;text-underline-offset:3px}.question-practice-layout .question-verdict{margin:0 20px 20px;padding:13px 15px;border-radius:10px;font-size:12px;background:#fff3f3;border:1px solid #f2c9c9;color:#b34545}.question-practice-layout .question-verdict.correct{background:#ecf9f3;border-color:#bde8d6;color:#17724f}.question-practice-layout .question-explanation{margin:0 20px 20px;padding:18px;border-radius:12px;background:#f7f9fc;border:1px solid #d9e1ec}.question-practice-layout .question-explanation .markdown pre{font:13px/1.75 Consolas,Menlo,monospace}.question-practice-layout .current-subquestion{padding:0;border-radius:15px;overflow:hidden}.question-practice-layout .current-subquestion .question-text-panel{border:0;border-radius:0}.question-practice-layout .current-subquestion .answer-box{margin:0 18px 18px}.question-practice-layout .current-subquestion>.practice-question>.question-heading{margin:0;padding:12px 18px;min-height:54px}.question-practice-layout .subquestion-navigation{position:sticky;top:72px;z-index:5;margin:16px 0;padding:10px;border:1px solid var(--line);border-radius:12px;background:#fffffff0;-webkit-backdrop-filter:blur(8px);backdrop-filter:blur(8px)}.question-practice-layout .subquestion-navigation>div{flex-wrap:nowrap;overflow-x:auto}.question-practice-layout .subquestion-navigation a{min-width:38px;height:36px;padding:0 9px;display:grid;place-items:center;border-color:#dce3ed;background:#f8fafc;color:#65748a;font-size:12px;font-weight:900;white-space:nowrap}.question-practice-layout .subquestion-navigation a[aria-current=page]{background:#edf4ff;color:var(--blue);border-color:var(--blue);box-shadow:none}.question-practice-layout .practice-question-nav{margin-top:22px;border:0;padding-top:0}.question-practice-layout .practice-question-nav button{padding:10px 14px}.question-practice-layout .practice-question-nav small{display:inline;margin-left:4px;font-weight:500}.practice-related-column{position:sticky;top:98px;display:grid;gap:16px}.practice-related-column .related-practice{position:static;padding:21px;border-radius:18px;box-shadow:0 10px 34px #1d32520b}.practice-related-column .related-practice h2{font-size:20px;margin:6px 0 16px}.practice-related-column .related-question{padding:13px 3px;border-top:1px solid #edf0f4;border-bottom:0}.practice-related-column .related-question strong{font-weight:700;line-height:1.45}.practice-related-column .related-all{font-size:13px;font-weight:700;padding-top:15px;border-top:1px solid #edf0f4;margin:0}.practice-related-column .material-progress-card{background:#fff;border:1px solid var(--line);border-radius:18px;padding:21px;box-shadow:0 10px 34px #1d32520b}.material-progress-card h2{font-size:20px;margin:6px 0 16px}@media(max-width:1100px){.question-practice-layout{grid-template-columns:minmax(0,1fr)}.practice-related-column{position:static;grid-template-columns:1fr 1fr}}@media(max-width:700px){main:has(>.topics-layout),main:has(>.question-practice-layout){width:min(calc(100% - 20px),680px);margin-top:12px}.question-practice-layout .question-practice-card{padding:20px 16px}.question-practice-layout .question-text-panel>.markdown,.question-practice-layout .shared-material .paper-content .markdown{padding:20px 16px;font-size:15px}.question-practice-layout .answer-options{padding:0 16px 18px}.question-practice-layout .boolean-options{grid-template-columns:1fr}.question-practice-layout .question-answer-actions{gap:6px;padding-left:14px;padding-right:14px}.question-practice-layout .question-answer-actions button{padding:10px 8px;font-size:12px;white-space:nowrap}.practice-related-column{grid-template-columns:1fr}}