@font-face{font-family:Geist;src:url('assets/geist-latin.woff2') format('woff2');font-style:normal;font-weight:400 700;font-display:swap}
:root{
  --page:#f5f6f3;--surface:#fff;--surface-soft:#f1f4ee;--ink:#24342c;--secondary:#5d6c62;
  --muted:#63705f;--green:#285840;--green-hover:#1c4630;--green-soft:#e8efe4;--line:#e1e6dc;
  --line-strong:#cdd7c6;--warning-bg:#faf5e9;--warning-ink:#7c5c2d;--danger-bg:#f9eee9;--danger-ink:#904728;
  --radius:12px;--layer-header:10;--layer-backdrop:20;--layer-drawer:30;--layer-toast:50;
  --ease:cubic-bezier(.2,.7,.2,1);--font:Geist,"PingFang SC","Microsoft YaHei","Noto Sans CJK SC",sans-serif;
}
*{box-sizing:border-box}html{scroll-padding-top:90px}body{margin:0;background:var(--page);color:var(--ink);font:14px/1.6 var(--font);-webkit-font-smoothing:antialiased}
button,input,textarea,select{font:inherit}button,a,input,textarea,select{-webkit-tap-highlight-color:transparent}button{cursor:pointer;color:inherit}button:disabled{cursor:default;opacity:.4}a{color:inherit;text-decoration:none}button{border:0}button,a{touch-action:manipulation}
button,a,select{transition:background-color 160ms var(--ease),color 160ms var(--ease),border-color 160ms var(--ease),transform 160ms var(--ease)}button:not(:disabled):active,.primary:active,.secondary:active{transform:translateY(1px)}button:focus-visible,a:focus-visible,summary:focus-visible,input:focus-visible,textarea:focus-visible,select:focus-visible{outline:3px solid #8aaa70;outline-offset:3px}
::selection{background:#d7e5c9;color:#213e2a}h1,h2,h3,p{margin:0}h1,h2,h3{text-wrap:balance}p{text-wrap:pretty}img{max-width:100%}.icon{display:inline-block;width:19px;height:19px;fill:none;stroke:currentColor;stroke-width:1.65;stroke-linecap:round;stroke-linejoin:round;flex-shrink:0;vertical-align:middle}.icon-definitions{position:absolute;width:0;height:0;overflow:hidden}.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}[hidden]{display:none!important}
.skip-link{position:fixed;top:10px;left:16px;z-index:var(--layer-toast);padding:12px 18px;background:var(--green);color:#fff;border-radius:6px;transform:translateY(-160%)}.skip-link:focus{transform:translateY(0)}
.app-header{position:sticky;top:0;z-index:var(--layer-header);background:var(--surface);border-bottom:1px solid var(--line)}.header-inner{display:flex;align-items:center;gap:46px;max-width:1480px;margin:auto;padding:0 42px;height:78px}.brand{display:inline-flex;align-items:center;gap:11px;white-space:nowrap;font-size:18px;font-weight:600;letter-spacing:-.5px}.brand-mark{display:inline-flex;align-items:baseline;justify-content:center;width:35px;height:37px;border-radius:9px 9px 9px 2px;background:var(--green);color:#fff;font-size:28px;line-height:35px;font-weight:600;letter-spacing:-3px;padding-right:3px}.brand-mark>span{color:#c4d8ad;margin-left:2px;font-size:25px}.study-nav{display:flex;align-items:center;gap:5px;height:100%}.nav-item{display:inline-flex;align-items:center;justify-content:center;gap:8px;background:none;color:var(--secondary);height:42px;padding:0 13px;border-radius:6px;font-size:13px;white-space:nowrap}.nav-item .icon{width:17px;height:17px}.nav-item b{font-size:11px;line-height:1;padding:4px 5px;border-radius:4px;min-width:21px;text-align:center;font-weight:500;color:var(--muted);font-variant-numeric:tabular-nums}.nav-item.active{color:var(--green);background:var(--green-soft);font-weight:600}.nav-item.active b{background:#d7e4cf;color:#33572f}.nav-item:hover:not(.active){background:var(--page);color:var(--ink)}.header-tools{margin-left:auto;display:flex;align-items:center;gap:5px}.tool-button{height:42px;display:inline-flex;align-items:center;gap:7px;padding:0 11px;border-radius:6px;background:none;color:var(--secondary);font-size:13px}.tool-button:hover{background:var(--page)}.tool-button .icon{width:18px;height:18px}
.workspace{max-width:1480px;margin:auto;padding:0 42px}.workspace-intro{display:flex;justify-content:space-between;align-items:center;gap:40px;padding:36px 0 29px}.breadcrumb{display:flex;align-items:center;gap:12px;font-size:12px;color:var(--muted)}.breadcrumb>span:first-child{font-variant-numeric:tabular-nums;letter-spacing:1.1px;color:var(--secondary)}.breadcrumb strong{font-weight:400}.breadcrumb-divider{color:#929c90}.intro-copy h1{font-size:29px;line-height:1.4;font-weight:600;letter-spacing:-.7px;margin:11px 0 8px}.intro-copy h1>span{font-weight:400;color:#b2bdab;padding:0 2px}.intro-description{font-size:13px;color:var(--secondary)}.study-summary{width:268px;flex-shrink:0;padding-left:26px;border-left:1px solid var(--line-strong)}.summary-numbers{display:flex;align-items:center;gap:33px}.summary-numbers>div{display:flex;align-items:baseline;gap:9px}.summary-numbers strong{font-size:27px;font-weight:500;line-height:1.25;letter-spacing:-1px;font-variant-numeric:tabular-nums}.summary-numbers strong small{font-size:12px;font-weight:400;color:var(--secondary);letter-spacing:0}.summary-numbers>div>span{font-size:11px;color:var(--secondary)}.summary-book{margin-left:auto;color:#8fa380}.summary-book .icon{width:27px;height:27px;stroke-width:1.2}.progress-line{display:flex;justify-content:space-between;margin:14px 0 7px;font-size:11px;color:var(--secondary)}.progress-line b{font-weight:500;color:var(--green);font-variant-numeric:tabular-nums}.progress-track{height:4px;overflow:hidden;border-radius:2px;background:#e0e7da}.progress-track i{display:block;height:100%;background:var(--green);transform-origin:left;width:0}
.bank-toolbar{display:flex;justify-content:space-between;align-items:center;gap:15px;border-bottom:1px solid var(--line-strong)}.type-tabs{display:flex;align-items:center;gap:28px;min-width:0}.type-tab{padding:11px 0 15px;position:relative;display:inline-flex;align-items:center;gap:9px;white-space:nowrap;background:none;color:var(--secondary);font-size:14px;line-height:1.4}.type-tab span{font-size:11px;font-variant-numeric:tabular-nums;font-weight:400;color:var(--muted)}.type-tab:after{content:'';position:absolute;left:0;right:0;bottom:-1px;height:2px;background:transparent}.type-tab.active{font-weight:600;color:var(--green)}.type-tab.active:after{background:var(--green)}.type-tab.active span{color:var(--green)}.type-tab:hover{color:var(--ink)}.text-button{display:inline-flex;align-items:center;justify-content:center;gap:7px;background:none;font-size:12px;color:var(--secondary);padding:9px 7px;border-radius:5px;min-height:38px}.text-button:hover{background:#eaf0e3;color:var(--green)}.text-button .icon{width:16px;height:16px}.random-button{margin-bottom:6px}.filters{display:flex;align-items:center;gap:10px;padding:19px 0 22px}.search{display:flex;align-items:center;gap:10px;flex:1;min-width:0;max-width:540px;background:var(--surface);border:1px solid var(--line);border-radius:7px;padding:0 12px;height:42px}.search:focus-within{border-color:#8da67b;box-shadow:0 0 0 2px #e4ecd9}.search>.icon{width:17px;height:17px;color:var(--muted)}.search input{min-width:0;width:100%;background:none;border:0;outline:none;padding:8px 0;color:var(--ink);font-size:13px}.search input:focus-visible{outline:none}.search input::placeholder{color:#65765b}.search kbd{font:11px var(--font);border:1px solid var(--line);border-radius:3px;padding:0 5px;color:var(--secondary)}.select-field{position:relative;min-width:130px}.select-field select{width:100%;height:42px;border:1px solid var(--line);border-radius:7px;background:var(--surface);color:var(--secondary);padding:0 32px 0 12px;font-size:12px;cursor:pointer;max-width:190px}.topic-filter{min-width:155px}.reset-button{padding:8px 10px}.mobile-catalog-bar{display:none}
.practice-layout{display:grid;grid-template-columns:290px minmax(0,1fr);gap:24px;align-items:start}.question-list-panel{position:sticky;top:100px;min-width:0;align-self:start;background:transparent;border-radius:9px;overflow:hidden}.list-header{display:flex;align-items:center;justify-content:space-between;padding:0 4px 14px}.list-header>div{display:flex;align-items:center;gap:10px}.list-header h2{font-size:13px;font-weight:600}.list-header #resultCount{font-size:11px;color:var(--muted)}#catalogClose{display:none}.question-list{max-height:calc(100dvh - 185px);overflow:auto;overscroll-behavior:contain;scrollbar-width:thin;scrollbar-color:#c9d4c2 transparent;padding:0 6px 5px 0}.question-item{display:grid;grid-template-columns:28px minmax(0,1fr);align-items:start;gap:11px;width:100%;text-align:left;border-left:2px solid transparent;border-radius:0 7px 7px 0;padding:16px 12px 15px 9px;background:transparent;margin:0 0 3px;color:var(--ink)}.question-item:hover{background:#eaf0e5}.question-item.selected{border-left-color:var(--green);background:var(--green-soft)}.item-index{font-size:12px;font-weight:400;line-height:1.5;color:#596f50;font-variant-numeric:tabular-nums;padding-top:2px}.item-body{min-width:0}.item-meta{display:flex;align-items:center;gap:6px;color:var(--secondary);font-size:10px;line-height:1.8}.item-year{font-weight:500;color:#536d45}.item-status{margin-left:auto;display:inline-flex;gap:3px;align-items:center;color:var(--green)}.item-status .icon{width:12px;height:12px}.question-item h3{font-size:13px;line-height:1.65;font-weight:500;margin:5px 0 5px;text-wrap:pretty}.item-tag{font-size:10px;color:var(--secondary)}.catalog-footer{display:flex;align-items:center;gap:6px;color:var(--secondary);font-size:10px;padding:14px 8px 2px}.catalog-footer .icon{width:13px;height:13px}
.question-panel{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);min-width:0;overflow:hidden;min-height:520px;box-shadow:0 3px 12px #263d2403}.question-panel:focus{outline:none}.question-head{padding:27px 32px 22px}.q-meta{display:flex;align-items:center;gap:10px;font-size:11px;color:var(--secondary);line-height:1.5}.year-badge{color:var(--green);background:#edf3e8;border-radius:4px;font-size:11px;padding:4px 8px;font-weight:500}.q-meta-divider{color:#a2af98}.favorite-btn{margin-left:auto;background:transparent;color:var(--secondary);width:36px;height:36px;border-radius:7px;display:flex;align-items:center;justify-content:center;flex-shrink:0}.favorite-btn .icon{width:21px;height:21px}.favorite-btn:hover{background:var(--page);color:var(--green)}.favorite-btn.on{color:var(--green)}.favorite-btn.on .icon{fill:#d6e6c7}.question-head h2{font-size:22px;line-height:1.5;font-weight:600;letter-spacing:-.35px;margin:12px 0 12px}.tags{display:flex;flex-wrap:wrap;gap:7px}.tags span{font-size:11px;line-height:1.5;color:#5c6e53;background:var(--surface-soft);border-radius:3px;padding:3px 7px}.q-source{color:var(--secondary);font-size:11px;margin-top:16px;line-height:1.9}.q-source a{display:inline;color:var(--green);border-bottom:1px solid #c4d4b9;padding-bottom:1px}.q-source .icon{width:11px;height:11px;margin-left:2px;vertical-align:baseline}.question-content{padding:0 32px 28px;min-width:0}.original-paper{border-top:1px solid var(--line);padding-top:21px;min-width:0}.image-hint{margin-bottom:15px;display:flex;align-items:center;justify-content:space-between;font-size:12px;font-weight:600;color:var(--secondary)}.image-hint>span:last-child{font-size:11px;font-weight:400;color:var(--muted)}
.math-content{font-size:16px;line-height:2;color:var(--ink);min-width:0;overflow-wrap:anywhere;word-break:normal}.math-content p{margin:12px 0}.math-content p:first-child{margin-top:0}.math-content strong{font-weight:600;color:var(--ink)}.math-content ol,.math-content ul{padding-left:1.5em;margin:12px 0}.math-content li{padding-left:3px;margin:7px 0}.math-content .katex{font-size:1.05em;max-width:100%}.math-content .katex-display{display:block;overflow-x:auto;overflow-y:hidden;padding:10px 2px 14px;margin:10px 0;text-align:center;scrollbar-width:thin}.math-content .katex-display>.katex{max-width:none}.math-content p>.katex,.math-content li>.katex{display:inline-block;max-width:100%;overflow-x:auto;overflow-y:hidden;vertical-align:middle;padding:3px 0;scrollbar-width:thin}.math-content pre{max-width:100%;overflow:auto;padding:20px;background:#f5f7f1;border:1px solid #e5eadd;border-radius:7px;font-size:13px;line-height:1.95;tab-size:4;scrollbar-width:thin}.math-content pre code{font:inherit;white-space:pre;overflow-wrap:normal;word-break:normal;background:none;padding:0}.math-content :not(pre)>code{font:13px/1.8 ui-monospace,SFMono-Regular,Consolas,monospace;background:#f0f4e9;border-radius:3px;padding:2px 5px;overflow-wrap:anywhere}.heap-diagram{max-width:100%;margin:20px 0;padding:15px;border:1px solid var(--line);border-radius:7px;background:#fff;text-align:center}.heap-diagram img{display:block;width:auto;max-width:100%;max-height:760px;height:auto;margin:auto;cursor:zoom-in}.heap-diagram figcaption{font-size:11px;color:var(--secondary);margin-top:10px}.original-toggle{margin-top:19px;padding-top:11px;font-size:11px;color:var(--secondary)}.original-toggle summary{cursor:pointer;width:fit-content;padding:5px 0;list-style-position:inside}.original-toggle summary:hover{color:var(--green)}.original-scan{margin-top:15px}.source-image{display:block;max-width:100%;width:100%;height:auto;cursor:zoom-in;margin:8px 0 12px}
.bool-options{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin:25px 0 24px}.bool-option{display:flex;align-items:center;gap:12px;min-height:61px;padding:12px 17px;border:1px solid var(--line-strong);background:var(--surface);border-radius:7px;font-size:13px;color:var(--secondary)}.option-key{font-size:19px;line-height:1;font-weight:500;color:var(--ink)}.option-check{margin-left:auto;width:19px;height:19px;opacity:0;color:var(--green)}.bool-option.selected{background:#eff5e9;border-color:#789464;color:var(--green)}.bool-option.selected .option-check{opacity:1}.bool-option:hover{border-color:#8ca37a;background:#f9fbf6}.answer-label{display:flex;align-items:center;justify-content:space-between;gap:12px;font-size:13px;font-weight:500;color:var(--ink);margin:23px 0 10px}.saved-label{display:inline-flex;align-items:center;gap:4px;font-size:10px;color:var(--secondary);font-weight:400}.saved-label .icon{width:12px;height:12px}.response-input,.note-input{resize:vertical;width:100%;min-height:125px;display:block;border:1px solid var(--line-strong);border-radius:7px;padding:14px 16px;background:#fcfdfb;color:var(--ink);font-size:14px;line-height:1.85}.response-input::placeholder,.note-input::placeholder{color:#65765b;font-size:13px}.response-input:focus,.note-input:focus{background:#fff;border-color:#779464}.note-input{min-height:85px}.action-row{display:flex;align-items:center;gap:13px;margin:17px 0 0;flex-wrap:wrap}.primary,.secondary{display:inline-flex;align-items:center;justify-content:center;gap:8px;min-height:43px;line-height:1.5;border-radius:6px;padding:11px 17px;border:1px solid transparent;font-size:12px;font-weight:500;text-align:center}.primary{background:var(--green);color:#fff}.primary:hover{background:var(--green-hover)}.primary .icon,.secondary .icon{width:16px;height:16px}.secondary{background:#fff;color:var(--green);border-color:var(--line-strong)}.secondary:hover{background:var(--surface-soft);border-color:#a8b89d}.action-hint{font-size:11px;color:var(--secondary)}.result-box{padding:15px 17px;background:#edf5e7;border-radius:7px;font-size:13px;color:#365b2a;margin-top:23px;line-height:1.9}.result-box>.icon{margin-right:6px;width:16px;height:16px}.result-box small{display:block;font-size:11px;color:var(--secondary);margin-top:3px}.result-box.wrong{background:var(--danger-bg);color:var(--danger-ink)}.answer-section{margin-top:25px;border-top:1px solid var(--line);padding-top:25px;min-width:0}.answer-section h3{display:flex;align-items:center;gap:8px;font-size:16px;color:var(--green);font-weight:600;margin-bottom:8px}.answer-section h3 .icon{width:18px;height:18px}.answer-section>.muted{font-size:11px;margin-bottom:15px}.answer-section>.muted+.muted{margin-top:-9px}.review-note{padding:15px 17px;background:var(--warning-bg);color:var(--warning-ink);font-size:12px;border-left:2px solid #c9b276;border-radius:0 5px 5px 0;margin:20px 0;line-height:1.9}.review-note strong{display:block;font-size:11px;font-weight:600;margin-bottom:5px}.self-rating{display:flex;gap:8px;flex-wrap:wrap;margin:12px 0}.rating{display:inline-flex;align-items:center;gap:6px;min-height:40px;border:1px solid var(--line-strong);background:var(--surface);border-radius:6px;padding:9px 12px;font-size:12px;color:var(--secondary)}.rating .icon{width:15px;height:15px}.rating:hover{background:#f5f8f0;color:var(--green)}.rating.chosen{background:var(--green-soft);border-color:#9ab28a;color:var(--green)}.question-foot{display:flex;align-items:center;justify-content:space-between;border-top:1px solid var(--line);padding:13px 23px;background:#fcfdfb;gap:8px}.question-foot>span{font-size:11px;color:var(--secondary);font-variant-numeric:tabular-nums}.question-foot button{display:inline-flex;align-items:center;gap:8px;min-height:36px;font-size:12px;padding:7px 9px;border-radius:5px;background:none;color:var(--green)}.question-foot button:hover:not(:disabled){background:var(--green-soft)}.question-foot .icon{width:15px;height:15px}
.empty{padding:70px 28px;text-align:center;color:var(--secondary);font-size:13px;line-height:1.9}.empty h3{font-size:18px;font-weight:500;color:var(--ink);margin-bottom:12px}.empty p{margin:0 auto 21px;max-width:300px}.empty-icon{display:flex;align-items:center;justify-content:center;margin:0 auto 20px;width:55px;height:55px;background:var(--surface-soft);border-radius:50%;color:var(--green)}.empty-icon .icon{width:24px;height:24px;stroke-width:1.4}.question-list .empty{padding:35px 16px;font-size:12px}.site-footer{display:flex;align-items:center;justify-content:space-between;gap:15px;padding:28px 0 35px;color:var(--secondary);font-size:11px}.footer-year{margin-left:10px;font-variant-numeric:tabular-nums;color:#616f5b}
.icon-button{display:inline-flex;align-items:center;justify-content:center;flex-shrink:0;background:var(--surface-soft);color:var(--secondary);width:36px;height:36px;border-radius:7px}.icon-button:hover{background:#e5ecdd;color:var(--green)}.icon-button .icon{width:18px;height:18px}.eyebrow{font-size:11px;font-weight:500;color:var(--green);margin-bottom:7px}.muted{color:var(--secondary);font-size:13px;line-height:1.9}.small{font-size:11px}dialog{border:1px solid var(--line);border-radius:14px;box-shadow:0 22px 100px #263d2424;padding:30px;width:min(600px,calc(100% - 32px));max-height:88dvh;overflow:auto;color:var(--ink);font-family:var(--font)}dialog::backdrop{background:#1f352c70;backdrop-filter:blur(4px)}.dialog-head{display:flex;align-items:center;justify-content:space-between;gap:15px;margin-bottom:17px}.dialog-head h2{font-size:21px;font-weight:600;letter-spacing:-.4px}dialog h3{font-size:14px;font-weight:600;margin:24px 0 12px}.download-grid{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin:24px 0}.download-card{border:1px solid var(--line);border-radius:7px;padding:16px}.download-card strong{display:block;font-size:13px;font-weight:500;margin-bottom:12px}.download-card a{display:inline-flex;gap:6px;align-items:center;font-size:12px;color:var(--green);margin-right:16px;padding:3px 0;border-bottom:1px solid #c5d5b8}.download-card a .icon{width:12px;height:12px}.download-card a:last-child{margin-right:0}.original-row{display:flex;align-items:center;gap:22px;padding:14px 1px;border-bottom:1px solid var(--line);font-size:12px}.original-row>span{margin-right:auto}.original-row a{color:var(--green)}.original-row a .icon{width:11px;height:11px;margin-left:3px}.full{width:100%;margin-top:12px}.file-label{cursor:pointer}.download-help{font-size:11px;text-align:center;color:var(--secondary);margin:8px 0 3px}#resourceDialog>.small{margin:15px 0}#backupMessage{margin-top:15px}#imageDialog{width:min(1100px,96vw);padding:15px}#imageDialog>.icon-button{position:sticky;top:0;float:right}#imageDialog img{display:block;width:100%;min-width:760px;clear:both}.toast{position:fixed;bottom:25px;left:50%;max-width:calc(100% - 32px);transform:translate(-50%,15px);background:#254b36;color:#fff;padding:12px 21px;font-size:12px;border-radius:7px;z-index:var(--layer-toast);opacity:0;pointer-events:none;transition:opacity 160ms var(--ease),transform 200ms var(--ease);box-shadow:0 8px 30px #243d2420}.toast.visible{opacity:1;transform:translate(-50%,0)}.catalog-backdrop{position:fixed;inset:0;z-index:var(--layer-backdrop);background:#22392d60;backdrop-filter:blur(3px)}
@media(min-width:1600px){.workspace,.header-inner{padding-left:54px;padding-right:54px}.practice-layout{grid-template-columns:305px minmax(0,1fr);gap:30px}.question-head{padding:32px 42px 25px}.question-content{padding:0 42px 32px}}
@media(max-width:1200px){.header-inner{gap:24px;padding:0 28px}.workspace{padding:0 28px}.nav-item{padding:0 10px;gap:6px}.nav-item .icon{display:none}.tool-button span{display:none}.tool-button{width:36px;padding:0;justify-content:center}.practice-layout{grid-template-columns:250px minmax(0,1fr);gap:20px}.question-head{padding:25px 25px 20px}.question-content{padding:0 25px 26px}.type-tabs{gap:25px}.study-summary{width:250px}.summary-numbers{gap:24px}.summary-book{display:none}}
@media(max-width:900px){.header-inner{flex-wrap:wrap;justify-content:space-between;gap:0;height:auto;padding:16px 24px 0}.brand{font-size:17px}.brand-mark{width:31px;height:33px;font-size:25px;line-height:32px}.header-tools{margin-left:auto;gap:3px}.tool-button{width:39px;height:38px}.study-nav{order:3;flex-basis:100%;height:55px;gap:24px;margin-top:12px}.nav-item{padding:0;height:55px;border-radius:0;background:none;gap:8px;position:relative;font-size:13px}.nav-item.active{background:none}.nav-item.active:after{content:'';position:absolute;bottom:-1px;left:0;right:0;height:2px;background:var(--green)}.nav-item .icon{display:block;width:16px;height:16px}.nav-item b{background:none;padding:0;min-width:0}.nav-item.active b{background:none}.workspace{padding:0 24px}.workspace-intro{padding:27px 0 25px}.intro-copy h1{font-size:25px}.intro-description{font-size:12px}.study-summary{width:220px;padding-left:20px}.summary-numbers{gap:20px}.summary-numbers>div{gap:7px}.summary-numbers strong{font-size:25px}.summary-numbers>div>span{font-size:10px}.type-tabs{gap:25px}.practice-layout{grid-template-columns:minmax(0,1fr)}.question-head{padding:27px 30px 23px}.question-content{padding:0 30px 28px}.question-panel{min-height:450px}.mobile-catalog-bar{display:flex;align-items:center;justify-content:space-between;gap:10px;margin:0 0 15px}.mobile-catalog-bar>span{font-size:11px;color:var(--secondary);font-variant-numeric:tabular-nums}.mobile-catalog-bar .secondary{padding:8px 11px;min-height:37px;font-size:11px}.mobile-catalog-bar .icon{width:15px;height:15px}.question-list-panel{display:none;position:fixed;inset:0 auto 0 0;width:min(360px,88vw);height:100dvh;z-index:var(--layer-drawer);background:var(--surface);border-radius:0;padding:24px 14px 16px 18px;box-shadow:12px 0 50px #233a2415}.catalog-open .question-list-panel{display:flex;flex-direction:column;animation:drawer-enter 220ms var(--ease)}.catalog-open{overflow:hidden}.question-list{max-height:none;flex:1;min-height:0}.list-header{padding:0 5px 20px}.list-header h2{font-size:17px}.list-header>div{display:block}.list-header #resultCount{display:block;font-size:12px;margin-top:6px}#catalogClose{display:flex}.question-item{grid-template-columns:28px minmax(0,1fr);padding-top:17px;padding-bottom:17px}.question-item h3{font-size:14px}.item-meta{font-size:11px}.item-tag{font-size:11px}.catalog-footer{font-size:11px;padding-top:20px}.search{max-width:none}.filters{padding-bottom:15px}.site-footer{font-size:10px}.app-header{position:relative}.type-tab{font-size:13px}.type-tab span{font-size:11px}}
@media(max-width:600px){.header-inner{padding:15px 18px 0}.brand{font-size:16px;gap:9px}.header-tools{gap:1px}.tool-button{width:36px}.tool-button .icon{width:18px;height:18px}.study-nav{justify-content:space-between;gap:12px;margin-top:9px;height:51px}.nav-item{height:51px;gap:6px;font-size:12px}.nav-item .icon{display:none}.nav-item b{font-size:10px}.workspace{padding:0 18px}.workspace-intro{display:block;padding:25px 0 20px}.breadcrumb{font-size:11px;gap:9px}.intro-copy h1{font-size:25px;letter-spacing:-.8px;margin:10px 0 7px}.intro-copy h1>span{padding:0}.intro-description{font-size:11px;line-height:1.8}.study-summary{display:flex;align-items:center;gap:16px;margin-top:21px;padding:0;width:auto;border:0}.summary-numbers{gap:21px}.summary-numbers>div{gap:7px;align-items:center}.summary-numbers strong{font-size:20px;letter-spacing:-.6px}.summary-numbers strong small{font-size:10px}.summary-numbers>div>span{font-size:10px;white-space:nowrap}.progress-line{display:none}.progress-track{flex:1;max-width:110px;height:3px}.bank-toolbar{gap:8px}.type-tabs{gap:0;flex:1;justify-content:space-between}.type-tab{font-size:12px;gap:4px;padding:11px 0 13px}.type-tab span{font-size:9px}.random-button{padding:7px;min-height:36px;margin-bottom:3px}.random-button>span{display:none}.random-button .icon{width:17px;height:17px}.filters{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1.2fr) auto;gap:9px;padding:15px 0 13px}.search{grid-column:1/-1;width:100%;height:42px}.search input{font-size:13px}.search kbd{display:none}.select-field,.topic-filter{min-width:0}.select-field select{max-width:none;height:39px;padding-left:10px;padding-right:20px;font-size:11px}.reset-button{min-height:39px;padding:7px;font-size:11px}.mobile-catalog-bar{margin-bottom:13px}.question-head{padding:20px 19px 18px}.q-meta{gap:7px;font-size:10px}.year-badge{font-size:10px;padding:4px 7px}.q-meta-divider{display:none}.favorite-btn{width:32px;height:32px}.favorite-btn .icon{width:20px;height:20px}.question-head h2{font-size:19px;line-height:1.6;margin:10px 0 11px;letter-spacing:-.3px;text-wrap:pretty}.tags span{font-size:10px;padding:3px 6px}.q-source{font-size:10px;margin-top:13px;line-height:1.9}.question-content{padding:0 19px 23px}.original-paper{padding-top:18px}.image-hint{font-size:11px;margin-bottom:13px}.image-hint>span:last-child{font-size:10px}.math-content{font-size:16px;line-height:2}.math-content pre{font-size:12px;padding:15px 12px}.math-content .katex{font-size:1em}.bool-options{gap:10px;margin:21px 0 22px}.bool-option{min-height:56px;padding:11px 12px;font-size:12px;gap:10px}.option-key{font-size:18px}.option-check{width:17px;height:17px}.answer-label{font-size:12px;margin-top:22px;gap:7px}.saved-label{font-size:9px}.saved-label .icon{width:11px;height:11px}.response-input,.note-input{font-size:16px;padding:12px;min-height:122px}.response-input::placeholder,.note-input::placeholder{font-size:12px}.note-input{min-height:85px}.action-row{gap:10px}.action-row>.primary{width:100%;min-height:44px;font-size:13px}.action-hint{font-size:10px}.result-box{font-size:12px;padding:13px}.result-box small{font-size:10px}.answer-section h3{font-size:15px}.answer-section>.muted{font-size:10px}.review-note{font-size:11px;padding:13px 14px}.review-note strong{font-size:10px}.rating{font-size:11px;padding:8px 9px;gap:5px}.rating .icon{width:13px;height:13px}.self-rating{gap:6px}.question-foot{padding:11px 11px}.question-foot button{font-size:11px;gap:6px;padding:6px}.question-foot>span{font-size:10px}.question-foot .icon{width:14px;height:14px}.original-toggle{font-size:10px}.heap-diagram{padding:8px}.heap-diagram figcaption{font-size:10px}.site-footer{display:block;padding:25px 4px 30px;line-height:2;font-size:10px}.site-footer>span{display:block}.footer-year{margin-left:8px}.empty{padding:60px 20px}.download-grid{gap:9px}.download-card{padding:13px 12px}.download-card strong{font-size:12px}.download-card a{font-size:11px;margin-right:11px}.download-card .muted{font-size:10px}dialog{padding:23px 20px;border-radius:12px}.dialog-head h2{font-size:19px}.original-row{gap:17px;font-size:11px}.muted{font-size:12px}.toast{bottom:18px;max-width:calc(100% - 36px);width:max-content;font-size:11px;padding:11px 16px}}
@media(max-width:360px){.header-inner,.workspace{padding-left:14px;padding-right:14px}.study-nav{gap:8px}.nav-item{font-size:11px;gap:4px}.intro-copy h1{font-size:23px}.intro-description{font-size:10px}.study-summary{gap:10px}.summary-numbers{gap:16px}.summary-numbers>div{gap:5px}.type-tab{font-size:11px;gap:3px}.type-tab span{font-size:8px}.random-button{padding:5px}.question-head{padding:18px 15px 17px}.question-content{padding:0 15px 20px}.q-meta{gap:5px}.year-badge{font-size:9px}.question-head h2{font-size:18px}.self-rating{gap:5px}.rating{font-size:10px;padding:8px}.action-hint{font-size:9px}}
@keyframes drawer-enter{from{opacity:.5;transform:translateX(-20px)}to{opacity:1;transform:translateX(0)}}
@media(prefers-reduced-motion:reduce){*,*:before,*:after{animation:none!important;transition:none!important;scroll-behavior:auto!important}}
/* Keep progress labels together, and give long solutions a comfortable reading measure. */
.summary-numbers{gap:25px}.summary-numbers>div{flex-shrink:0}.summary-numbers strong,.summary-numbers>div>span{white-space:nowrap}.summary-book{display:none}.math-content{max-width:76ch}
.item-title{display:block;font-size:13px;line-height:1.65;font-weight:500;margin:5px 0;text-wrap:pretty}
@media(max-width:900px){.item-title{font-size:14px}}
@media(max-width:600px){.summary-numbers{gap:21px}}
@media(max-width:360px){.summary-numbers{gap:16px}}
@media(max-width:600px){.workspace-intro{padding-top:20px;padding-bottom:16px}.intro-description{display:none}.intro-copy h1{margin-bottom:0}.study-summary{margin-top:16px}}
.math-inline-group{display:inline-block;max-width:100%;overflow-x:auto;overflow-y:hidden;vertical-align:middle;padding:3px 0;white-space:nowrap;scrollbar-width:thin}
/* Keep the additional outline menu accessible on narrow screens. */
.brand,.header-tools{flex-shrink:0}.study-nav{min-width:0;overflow-x:auto;scrollbar-width:thin}.nav-item{flex-shrink:0}
@media(min-width:901px){.study-nav{flex:1}.header-inner{gap:24px}}
@media(max-width:900px){.study-nav{justify-content:flex-start;gap:22px}.nav-item{flex-shrink:0}}
@media(max-width:600px){.study-nav{gap:18px}}