@charset "UTF-8";
:root{--bg:#f5f6f2;--paper:#fff;--ink:#22332d;--muted:#7c8781;--line:#e5e9e2;--accent:#246858;--accent-light:#eaf2ec;--side:#fdfdf9;--font-size:18px;--shadow:0 9px 35px #22332d06;--wrong:#ac5549;--wrong-bg:#fff1ee}
*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--ink);font-family:-apple-system,BlinkMacSystemFont,"PingFang SC","Microsoft YaHei",sans-serif;font-size:14px;line-height:1.6}button,input,select{font:inherit;color:inherit}button,select{cursor:pointer}button{border:0;background:none}button:focus-visible,a:focus-visible,select:focus-visible,input:focus-visible,summary:focus-visible{outline:2px solid var(--accent);outline-offset:3px}a{color:var(--accent);text-decoration:none}button:disabled{cursor:default;opacity:.45}.sidebar{position:fixed;inset:0 auto 0 0;width:214px;border-right:1px solid var(--line);background:var(--side);padding:31px 18px;display:flex;flex-direction:column;z-index:10}.brand{display:flex;align-items:center;gap:11px;font-weight:650;font-size:21px;color:var(--ink);letter-spacing:1px}.brand-mark{display:flex;align-items:center;justify-content:center;width:40px;height:44px;border-radius:8px;background:var(--accent);color:#fff;font-family:serif;font-size:27px;font-weight:400}.brand small{display:block;margin-top:2px;color:var(--muted);font-size:10px;font-weight:400;letter-spacing:1px}.library-label{font-size:11px;color:var(--muted);margin:43px 10px 15px;display:flex;justify-content:space-between;letter-spacing:1px}.library-label span{font-size:9px;letter-spacing:2px;color:#a1aaa2}.nav-item{display:flex;align-items:center;text-align:left;gap:11px;width:100%;padding:11px 12px;margin:3px 0;border-radius:7px;font-size:13px;color:#62716a;white-space:nowrap}.nav-item:hover{background:var(--accent-light)}.nav-item.active{background:var(--accent-light);color:var(--accent);font-weight:600}.nav-symbol{font-size:17px;font-weight:400;width:19px;text-align:center}.nav-count{margin-left:auto;font-size:10px;font-variant-numeric:tabular-nums;color:var(--muted);font-weight:400}.side-divider{height:1px;background:var(--line);margin:25px 12px 17px}.side-bottom{margin-top:auto;font-size:10px;line-height:2.2;color:var(--muted);padding:25px 5px 0}.side-bottom a{font-size:9px;color:var(--muted)}.side-bottom button{display:block;padding:5px 0;color:var(--muted);font-size:10px}.status-dot{display:inline-block;width:5px;height:5px;background:#619174;border-radius:50%;vertical-align:middle;margin-right:5px}.workspace{margin-left:214px}.topbar{height:69px;display:flex;align-items:center;justify-content:space-between;padding:0 36px;border-bottom:1px solid var(--line)}.topbar-left,.topbar-tools{display:flex;align-items:center;gap:10px}.breadcrumb{font-size:12px;color:var(--muted)}.breadcrumb span{margin:0 12px;color:#c3cbc5}.breadcrumb b{color:var(--ink);font-weight:500}.icon-button{min-width:30px;height:30px;font-size:13px;border-radius:5px}.icon-button:hover{background:var(--accent-light)}.tool-divider{height:15px;width:1px;background:var(--line);margin:0 5px}.overview{padding:32px 36px 30px;display:flex;justify-content:space-between;align-items:center;gap:20px}.eyebrow{font-size:9px;letter-spacing:2.8px;color:var(--accent);font-weight:600}h1{font-family:"Songti SC","STSong",serif;font-size:27px;font-weight:600;letter-spacing:1px;margin:9px 0 8px}.overview p{color:var(--muted);font-size:12px;margin:0}.stats{display:flex;gap:24px;align-items:center;text-align:center;flex-shrink:0}.stats b{display:block;font-size:25px;letter-spacing:-1px;font-weight:550;font-variant-numeric:tabular-nums}.stats span{font-size:10px;color:var(--muted)}.stats i{height:30px;width:1px;background:var(--line)}.filterbar{padding:0 36px 23px;display:flex;gap:10px;align-items:center}.searchbox{display:flex;background:var(--paper);border:1px solid var(--line);border-radius:7px;align-items:center;flex:1;min-width:180px;height:42px}.searchbox>span{font-size:27px;color:var(--muted);padding:0 12px;line-height:1}.searchbox input{min-width:0;flex:1;border:0;outline:0;background:transparent;font-size:12px;height:100%;padding:0 5px}.searchbox input::placeholder{color:#9da59f}.filterbar select{background:var(--paper);border:1px solid var(--line);border-radius:7px;height:42px;font-size:12px;padding:0 12px;min-width:110px}.searchbox select{border:0;border-left:1px solid var(--line);height:24px;border-radius:0;font-size:11px;min-width:82px;padding:0 7px}.text-button{font-size:11px;color:var(--muted);padding:10px 3px;white-space:nowrap}.text-button:hover{color:var(--accent)}.content-grid{display:grid;grid-template-columns:274px minmax(0,1fr);margin:0 36px;gap:22px;align-items:start}.catalog{background:var(--paper);border:1px solid var(--line);border-radius:9px;overflow:hidden;position:sticky;top:18px;box-shadow:var(--shadow)}.catalog-heading{display:flex;align-items:center;justify-content:space-between;padding:18px 17px 14px;border-bottom:1px solid var(--line)}.catalog-heading h2{font-size:13px;font-weight:600;margin:0}.catalog-heading>span{font-size:10px;color:var(--muted)}.catalog-list{max-height:calc(100vh - 390px);min-height:280px;overflow:auto;padding:8px}.paper-row{display:block;width:100%;text-align:left;border:1px solid transparent;border-radius:6px;padding:13px 12px;margin-bottom:3px}.paper-row:hover{background:var(--bg)}.paper-row.active{background:var(--accent-light);border-color:#d6e5d9}.paper-row .row-title{font-size:12px;line-height:1.8;display:block}.paper-row.active .row-title{color:var(--accent);font-weight:550}.row-tags{display:flex;align-items:center;gap:6px;font-size:10px;color:var(--muted);margin-top:9px}.row-tags .module-tag{font-size:9px;background:var(--bg);padding:1px 5px;border:1px solid var(--line);border-radius:3px}.row-tags .row-count{margin-left:auto}.catalog-note{padding:11px;font-size:9px;color:var(--muted);text-align:center;border-top:1px solid var(--line)}.reader{min-width:0;outline:none}.reader-header{background:var(--paper);border:1px solid var(--line);border-radius:9px 9px 0 0;padding:24px 26px 18px}.reader-meta{display:flex;align-items:center;flex-wrap:wrap;gap:8px;font-size:10px;color:var(--muted)}.reader-meta .pill{background:var(--accent-light);color:var(--accent);border-radius:4px;padding:2px 7px}.reader-header h2{font-size:19px;font-weight:550;line-height:1.7;margin:9px 0 11px}.reader-actions{display:flex;justify-content:space-between;gap:10px;align-items:center;font-size:11px;color:var(--muted)}.reader-actions label{display:flex;gap:5px;align-items:center;white-space:nowrap}.reader-actions input{accent-color:var(--accent)}.reader-actions .all-answers{font-size:11px;color:var(--accent)}.page-strip{display:flex;justify-content:space-between;align-items:center;gap:12px;background:var(--paper);padding:11px 25px;border:1px solid var(--line);border-top:0;font-size:10px;color:var(--muted)}.page-strip select{font-size:10px;background:var(--paper);border:1px solid var(--line);padding:4px;border-radius:4px;max-width:95px}.page-buttons{display:flex;align-items:center;gap:8px}.page-buttons button{border:1px solid var(--line);background:var(--paper);border-radius:4px;padding:3px 9px;color:var(--ink)}.question-card{margin-top:16px;padding:24px 26px;background:var(--paper);border:1px solid var(--line);border-radius:9px;box-shadow:var(--shadow);scroll-margin-top:16px}.question-top{display:flex;justify-content:space-between;align-items:center;gap:10px;margin-bottom:16px}.question-number{display:flex;align-items:center;gap:10px}.question-number>b{display:inline-flex;align-items:center;justify-content:center;border:1px solid var(--line);border-radius:5px;width:28px;height:28px;font-size:12px;font-weight:600}.topic{font-size:10px;color:var(--muted)}.qid{color:var(--muted);font-size:9px;margin-left:auto}.save-button{font-size:20px;color:#89958d;padding:0 2px;line-height:1}.save-button.saved{color:#ad863b}.provenance{font-size:10px;color:var(--muted);margin:-6px 0 14px;border-bottom:1px solid var(--line);padding-bottom:10px}.rich{font-size:var(--font-size);line-height:1.95;overflow-wrap:anywhere}.rich p{margin:6px 0 12px}.rich>br:first-child{display:none}.rich table{border-collapse:collapse;max-width:100%;display:block;overflow:auto}.rich td,.rich th{border:1px solid var(--line);padding:7px}.rich img{max-width:100%;height:auto;object-fit:contain}.rich img.figure{display:block;margin:12px 0;max-height:500px;cursor:zoom-in}.rich img.formula{display:inline-block;vertical-align:middle;max-height:90px;max-width:min(100%,440px);cursor:zoom-in;margin:0 3px}.options{display:grid;gap:9px;margin:20px 0}.option{display:flex;align-items:baseline;gap:12px;text-align:left;padding:11px 15px;border:1px solid var(--line);border-radius:6px;background:var(--paper);width:100%;line-height:1.8;font-size:calc(var(--font-size) - 1px)}.option-label{display:flex;align-items:center;justify-content:center;min-width:23px;height:23px;font-size:11px;border-radius:50%;background:var(--bg);color:var(--muted)}.option .rich{font-size:inherit}.option .rich p{margin:0}.option .rich>br:last-child{display:none}.option:hover{border-color:#9cbbab;background:var(--accent-light)}.option.selected{border-color:var(--accent);background:var(--accent-light)}.option.selected .option-label{background:var(--accent);color:white}.option.correct{border-color:#75a28c;background:var(--accent-light)}.option.incorrect{border-color:#cf978d;background:var(--wrong-bg)}.question-bottom{display:flex;justify-content:space-between;align-items:center;margin-top:19px}.reveal-button{color:var(--accent);background:var(--accent-light);border:1px solid #d8e6da;font-size:11px;padding:8px 13px;border-radius:5px}.question-bottom .hint{font-size:9px;color:var(--muted)}.answer-box{margin-top:18px;border-top:1px dashed var(--line);padding-top:17px}.answer-line{font-size:13px;color:var(--accent);margin-bottom:10px;font-weight:550}.answer-line .result{font-weight:400;margin-left:12px;font-size:11px}.answer-line .wrong{color:var(--wrong)}.analysis-label{font-size:10px;color:var(--muted);margin:16px 0 8px;display:flex;gap:9px;align-items:center}.analysis-label span{font-size:9px;color:var(--muted);font-weight:400}.material{background:var(--paper);border:1px solid var(--line);border-left:3px solid #92ad91;border-radius:7px;margin-top:16px;padding:15px 22px}.material summary{font-size:12px;font-weight:550;color:var(--accent);cursor:pointer}.material .rich{font-size:calc(var(--font-size) - 1px);margin-top:14px}.missing-image{display:inline-block;padding:3px 7px;background:#fff4dc;color:#956c22;font-size:12px;border-radius:4px}.reader-placeholder{text-align:center;border:1px solid var(--line);border-radius:9px;background:var(--paper);padding:85px 25px}.reader-placeholder h2{font-weight:500;font-size:20px}.reader-placeholder p{color:var(--muted);font-size:12px}.large-mark{display:inline-flex;justify-content:center;align-items:center;background:var(--accent-light);color:var(--accent);width:62px;height:70px;border-radius:10px;font-size:35px;font-family:serif}.empty{font-size:12px;color:var(--muted);padding:28px 15px;text-align:center}.error-state{color:var(--wrong)}footer{padding:25px 36px;font-size:9px;color:var(--muted);text-align:right}footer span{margin:0 7px}dialog{border:1px solid var(--line);border-radius:12px;background:var(--paper);color:var(--ink);box-shadow:0 20px 80px #0004;max-width:90vw;padding:35px}dialog::backdrop{background:#172c24a8;backdrop-filter:blur(3px)}.dialog-close{position:absolute;top:8px;right:12px;font-size:27px;line-height:1.2;color:var(--muted);z-index:2}#image-dialog{max-width:95vw;max-height:94vh;text-align:center}#image-dialog img{display:block;max-width:85vw;max-height:78vh;object-fit:contain;background:#fff}#image-dialog p{font-size:11px;color:var(--muted);margin:12px 0 0}#about-dialog{width:530px;font-size:13px;line-height:1.95}#about-dialog h2{font-family:serif;font-size:24px;font-weight:500}#toast{position:fixed;bottom:28px;left:50%;transform:translateX(-50%);background:var(--ink);color:var(--paper);font-size:12px;border-radius:7px;padding:10px 20px;opacity:0;pointer-events:none;transition:opacity .15s;z-index:30}#toast.visible{opacity:1}.mobile-only{display:none}.loading{opacity:.5;pointer-events:none}body.dark{--bg:#17221e;--paper:#1e2b25;--side:#1a2721;--ink:#e0e8df;--muted:#99a69c;--line:#344339;--accent:#a0cbb1;--accent-light:#2c4034;--wrong:#e7ac9f;--wrong-bg:#4a302d;--shadow:none}body.dark .brand-mark{background:#375a46}body.dark .nav-item{color:#a2b1a7}body.dark .paper-row.active{border-color:#4e6d59}body.dark .missing-image{background:#56442b;color:#f1d497}body.dark .reveal-button{border-color:#4e6d59}body.dark .save-button.saved{color:#d4b770}body.dark .option.selected .option-label{background:#557b61}
@media(min-width:1600px){.content-grid{grid-template-columns:310px minmax(0,1fr)}.workspace{max-width:1720px}.reader-header,.question-card{padding-left:38px;padding-right:38px}.overview{padding-top:40px;padding-bottom:34px}}
@media(max-width:1200px){.sidebar{width:185px;padding-left:12px;padding-right:12px}.workspace{margin-left:185px}.topbar{padding:0 22px}.overview{padding:25px 22px}.overview h1{font-size:23px}.stats{gap:15px}.stats b{font-size:21px}.filterbar{padding-left:22px;padding-right:22px}.content-grid{margin:0 22px;grid-template-columns:235px minmax(0,1fr);gap:15px}.reader-header,.question-card{padding:20px}.catalog-list{max-height:calc(100vh - 360px)}.nav-item{font-size:12px;gap:8px;padding:10px}.nav-count{font-size:9px}.brand{font-size:19px}}
@media(max-width:1000px){.sidebar{width:171px;padding-left:8px;padding-right:8px}.workspace{margin-left:171px}.overview{align-items:start}.stats{gap:14px}.stats div:last-child,.stats i:last-of-type{display:none}.content-grid{grid-template-columns:200px minmax(0,1fr);gap:12px}.reader-header,.question-card{padding:18px}.reader-header h2{font-size:17px}.row-tags{gap:4px}.row-tags .module-tag{font-size:8px}.qid{display:none}.question-bottom .hint{display:none}.searchbox select{min-width:76px}.filterbar select{min-width:86px;padding:0 7px}.filterbar{gap:8px}.overview p{font-size:11px}.brand{font-size:18px;gap:7px}.brand-mark{width:34px;height:38px}.nav-item{padding:9px 8px}.side-bottom a{font-size:8px}}
@media(max-width:760px){.sidebar{display:none;top:60px;bottom:0;width:215px;box-shadow:8px 0 30px #0002}.sidebar.open{display:flex}.sidebar .brand,.sidebar .library-label{display:none}.sidebar .side-bottom{padding-top:20px}.workspace{margin-left:0}.mobile-only{display:inline-block}.topbar{height:60px;padding:0 16px}.topbar-left{gap:5px}.overview{padding:23px 17px 20px;display:block}.overview h1{font-size:24px}.stats{margin-top:19px;justify-content:start;gap:22px;text-align:left}.stats b{font-size:20px}.stats div:last-child,.stats i:last-of-type{display:block}.stats span{font-size:9px}.stats i{height:27px}.filterbar{padding:0 17px 17px;display:grid;grid-template-columns:1fr 1fr auto;gap:9px}.searchbox{grid-column:1/-1}.filterbar select{width:100%;height:37px}.searchbox select{width:88px;height:23px}.content-grid{margin:0 17px;display:block}.catalog{position:static;margin-bottom:15px}.catalog-list{min-height:0;max-height:200px;display:grid;grid-template-columns:1fr 1fr;padding:6px;gap:2px}.catalog-heading{padding:11px 14px}.catalog-note{display:none}.paper-row{padding:10px;margin:0;min-height:99px}.paper-row .row-title{font-size:11px}.row-tags{flex-wrap:wrap}.row-tags .row-count{margin-left:0}.question-card,.reader-header{padding:19px}.reader-header h2{font-size:18px}.page-strip{padding:10px 18px}.material{padding:15px}.rich{font-size:calc(var(--font-size) - 1px)}.reader-placeholder{padding:50px 20px}.reader-actions{font-size:10px}.reader-actions .all-answers{font-size:10px}.option{padding:10px;font-size:calc(var(--font-size) - 2px)}footer{padding:20px 17px;font-size:8px;text-align:center}.topbar-tools{gap:4px}dialog{padding:30px 18px}.library-label{margin-top:15px}}
@media print{.sidebar,.topbar,.overview,.filterbar,.catalog,footer,.save-button,.question-bottom,.page-strip,.reader-actions{display:none!important}.workspace{margin:0}.content-grid{display:block;margin:0}.question-card{break-inside:avoid;box-shadow:none}.answer-box[hidden]{display:none}.reader-header{border:0}.rich img.figure{max-height:300px}}

.source-note{font-size:11px;color:var(--muted);border-left:2px solid var(--line);padding:4px 10px;margin:14px 0}

.offline-panel{margin:20px 36px 0;background:var(--paper);border:1px solid var(--line);border-radius:9px;padding:17px 20px}.offline-panel.complete{border-color:#84a891}.offline-heading{display:flex;align-items:center;justify-content:space-between;gap:10px}.offline-heading h2{font-size:14px;margin:0}.offline-heading span{font-size:11px;color:var(--accent)}.offline-panel p{font-size:11px;color:var(--muted);margin:7px 0}.offline-panel progress{display:block;width:100%;height:8px;accent-color:var(--accent);margin:12px 0 8px}.offline-controls{display:flex;align-items:center;justify-content:space-between;gap:12px}.offline-controls span{font-size:10px;color:var(--muted)}.offline-controls button{padding:7px 12px;border-radius:5px;border:1px solid var(--line);font-size:11px;margin-left:6px}.offline-controls button:first-child{background:var(--accent-light);color:var(--accent)}@media(max-width:1200px){.offline-panel{margin-left:22px;margin-right:22px}}@media(max-width:760px){.offline-panel{margin:15px 17px 0;padding:15px}.offline-controls{display:block}.offline-controls div{margin-top:10px}.offline-controls button{margin-left:0;margin-right:7px;min-height:40px}.offline-heading span{font-size:10px}.option{min-height:44px}}

.catalog-more{display:block;width:100%;min-height:44px;color:var(--accent);font-size:12px;border-top:1px solid var(--line);margin-top:5px}