@charset "UTF-8";
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h1{font-size:40px;margin-top:45px}.login .panel{margin-top:30px}.login label{display:block;font-size:13px;margin:18px 0}.login .actions{margin-top:25px}.login .actions button{flex:1}#notice{position:fixed;left:50%;bottom:30px;transform:translateX(-50%);background:#234d3c;color:#fff;padding:14px 22px;border-radius:10px;font-size:13px;max-width:90vw;opacity:0;pointer-events:none;z-index:10}#notice.show{opacity:1}#import-preview{margin-top:20px}sup,sub{font-size:.7em;line-height:0}
@media(max-width:900px){.home-grid{grid-template-columns:1fr}.home-grid aside{display:grid;grid-template-columns:1fr 1fr;gap:18px}.topbar{padding:18px 24px;gap:10px}.topbar nav{gap:0}.nav{padding:9px;font-size:12px}.account{max-width:100px}.question-card{padding:28px}.small-stats{display:none}}
@media(max-width:600px){.topbar{flex-wrap:wrap;padding:16px 18px;gap:15px}.brand{font-size:21px}.topbar nav{order:3;width:100%;justify-content:space-between}.account{margin-left:auto}.topbar .nav{flex:1}main{padding:0 14px;margin-top:25px}h1{font-size:27px}.heading{gap:12px;align-items:flex-start}.heading>button{font-size:12px}.panel{padding:19px;border-radius:12px}.home-grid aside{display:block}.chapters{grid-template-columns:1fr 1fr;gap:6px}.chapter{font-size:10px;padding:8px 5px}.chapter small{display:none}.chapter input{width:12px;margin:2px}.section-title{flex-wrap:wrap}.start-row{gap:12px;flex-wrap:wrap}.start-row .primary{width:100%}.question-card{padding:20px 17px;border-radius:12px}.question-card h1{font-size:21px}.question-meta{align-items:flex-start}.stem .en{font-size:20px}.en{font-size:18px}.option{padding:14px 12px;gap:12px}.option.chosen,.option.correct{padding:13px 11px}.option-label{min-width:25px;height:25px}.zh{font-size:13px}.card-actions{gap:8px}.card-actions button{font-size:12px;padding:11px}.card-actions #next{margin-left:0}.source-actions{gap:10px}footer{padding:0 18px;display:block;line-height:1.8}footer span{display:block}.search label{min-width:100px}.search label.keyword{min-width:100%}.search>button{width:100%}.browse-row{gap:10px}.q-number{min-width:35px}.login h1{font-size:34px}.login{margin-top:35px}.metrics{gap:20px}.rationales{padding-left:16px}.answer{padding:18px}.question-card .section-title{gap:6px}.question-card .section-title button{padding:7px 10px}}

.option-raster{display:block;max-width:100%;height:auto}

.report-text{white-space:pre-wrap;overflow-wrap:anywhere;font:14px/1.9 "Microsoft YaHei",sans-serif}

.account{white-space:nowrap}.image-button.formula{width:100%;overflow-x:auto}.option-body{overflow-x:auto}#zoom img{width:auto;min-width:850px;max-width:none}#zoom button{left:0}@media(max-width:600px){.formula img{min-width:700px;max-width:none}.option-raster{min-width:550px;max-width:none}}

.chapter-range{display:flex;align-items:end;gap:12px;flex-wrap:wrap;padding:14px 0}.chapter-range label{flex:1;min-width:110px}.chapter-range>span{padding-bottom:12px}.range-shortcuts{display:flex;gap:14px;align-items:center;flex-wrap:wrap}.scope-description{padding:10px 12px;background:var(--soft,#eef4ee);border-radius:8px;font-size:14px;line-height:1.7}

.option.reference{border-style:dashed;border-color:#a98236;background:#faf6e9}

/* Detailed explanations: normal document flow, readable math, no truncated cards. */
.answer{background:#f8faf6;padding:26px;overflow-wrap:anywhere}.answer-heading .eyebrow{display:block;margin-bottom:5px}.answer-reference{background:#fff;border:1px solid #dce7d9;border-left:4px solid var(--green);padding:18px;border-radius:9px}.answer-reference .en{font-size:17px}.analysis-section{margin-top:27px;padding-top:22px;border-top:1px solid #dde6d8}.analysis-section h3{display:flex;align-items:center;gap:10px;font-size:16px;margin:0 0 15px}.analysis-section h3>span{font-size:11px;font-weight:500;color:#769281;letter-spacing:1px}.answer .concept{font-size:17px;font-weight:600;color:#285b48;margin:0}.explain{white-space:normal}.prose{font-size:14px;line-height:1.95;min-width:0;overflow-wrap:anywhere}.prose p{margin:10px 0;line-height:1.95}.prose>p:first-child{margin-top:0}.prose>p:last-child{margin-bottom:0}.prose strong{color:#214e3d}.prose ul,.prose ol{padding-left:23px}.prose li{margin:8px 0}.prose h4,.assumptions h4{font-size:14px;margin:16px 0 8px}.prose blockquote{margin:16px 0;padding:5px 15px;border-left:3px solid #aac4ac;background:#edf3e9}.prose table{display:block;max-width:100%;overflow-x:auto;border-collapse:collapse;font-size:13px}.prose th,.prose td{padding:9px 12px;border:1px solid #d5dfd1}.prose code{font-size:.94em;background:#eaf0e6;padding:2px 4px;border-radius:3px}.prose pre{overflow:auto;max-width:100%;padding:12px;background:#edf1e8}.assumptions{font-size:13px;color:#5a6d60;padding:1px 15px 8px;margin-top:14px;border-radius:8px;background:#edf3e8}.assumptions ul{padding-left:20px}.assumptions li p{margin:6px 0;font-size:13px}.rationales{list-style:none;padding:0;display:grid;gap:10px;margin:0}.rationales>li{display:flex;align-items:flex-start;gap:12px;border:1px solid #e0e7da;border-radius:9px;background:#fff;padding:14px;margin:0}.rationale-label{display:grid;place-items:center;flex:0 0 27px;height:27px;border-radius:6px;color:#3d6851;background:#edf3e7;font-size:12px}.rationales .prose{flex:1}.pitfalls{background:#fbf7eb;border:1px solid #eadfbd;border-radius:10px;padding:18px}.pitfalls h3{color:#705822}.pitfalls ul{padding-left:20px;margin:0}.pitfalls li{padding-left:3px;margin:12px 0}.pitfalls li::marker{color:#aa843c}.analysis-credit{font-size:11px!important;color:#778472;margin-top:20px}.prose .katex{font-size:1.13em}.katex-display{overflow-x:auto;overflow-y:hidden;max-width:100%;padding:12px 4px;margin:16px 0;background:#fff;border-radius:7px}.katex-display>.katex{display:inline-block;min-width:100%;text-align:center}.math-error{display:inline-block;color:#886621;border-bottom:1px dashed #b99f63;font-size:13px}.review-notes{margin-top:22px}.review-notes .prose{font-size:13px}.review-notes .prose p{font-size:13px}
@media(max-width:600px){.answer{padding:17px 13px;margin:23px -4px}.answer-reference{padding:13px}.analysis-section{margin-top:23px;padding-top:18px}.analysis-section h3{font-size:15px}.rationales>li{padding:12px 10px;gap:9px}.prose{font-size:14px}.pitfalls{padding:15px 12px}.katex-display{font-size:13px}.answer .concept{font-size:16px}}
.answer .prose{font-size:15px}.answer .prose p{font-size:inherit}.answer .review-notes .prose{font-size:13px}
.home-stats{justify-content:flex-end;margin-bottom:20px}.topbar .brand{white-space:normal;text-align:left;line-height:1.5}.login .brand{white-space:normal}
@media(max-width:900px){.home-stats{display:none}}
@media(max-width:600px){.topbar .brand{font-size:20px;flex:1;min-width:0;letter-spacing:0}}