:root{--bg:#f6f4ed;--paper:#fffef9;--ink:#303c35;--muted:#81867c;--line:#e4e5da;--accent:#536e5d;--soft:#eaf0e7;--gold:#bb9c69;--red:#a85642;--red-bg:#fbefea;font-family:Inter,"Segoe UI","Microsoft YaHei",sans-serif;color:var(--ink);background:var(--bg);font-synthesis:none}
*{box-sizing:border-box}body{margin:0}button,input,select{font:inherit}button,a,label.file-label{-webkit-tap-highlight-color:transparent}button{cursor:pointer}button:disabled{opacity:.45;cursor:not-allowed}button:focus-visible,a:focus-visible,summary:focus-visible{outline:3px solid #b0bf9d;outline-offset:3px}button{color:inherit}a{color:var(--accent)}[hidden]{display:none!important}.sidebar{position:fixed;inset:0 auto 0 0;width:232px;background:#eeeee4;border-right:1px solid var(--line);padding:37px 25px;display:flex;flex-direction:column}.brand{display:flex;gap:13px;align-items:center;text-decoration:none;color:var(--ink);font-size:25px;font-weight:650;letter-spacing:3px}.brand small{display:block;font-size:9px;letter-spacing:2px;margin-top:4px}.brand-mark{display:flex;align-items:center;justify-content:center;position:relative;width:44px;height:46px;border-radius:14px;background:var(--accent);font-family:Georgia,serif;font-size:37px;color:var(--paper);letter-spacing:-5px;padding-right:4px}.brand-mark span{position:absolute;color:#d6b887;font-size:40px;left:27px;top:-20px}.side-label{font-size:11px;color:var(--muted);letter-spacing:1px;margin:28px 0 32px}.nav{border:0;width:100%;background:none;text-align:left;display:flex;align-items:center;gap:12px;font-size:13px;padding:15px 14px;margin-bottom:9px;border-radius:9px;color:#747b70}.nav span{font-size:20px}.nav b{margin-left:auto;font-size:10px;font-weight:500;border-radius:5px;background:#e3e6db;padding:3px 7px}.nav.active{background:#dfe6d8;color:#3e5c49;font-weight:600}.side-deck{margin:35px 12px 0;border-top:1px solid #d8dece;padding-top:24px}.eyebrow{font-size:10px;letter-spacing:1.7px;color:#8b9284;font-weight:600}.side-deck strong{display:block;font-size:13px;margin:13px 0 17px}.progress-line,.round-track{background:#e3e6da;height:4px;overflow:hidden;border-radius:3px}.progress-line i,.round-track i{display:block;background:#849a78;height:100%;width:0;transition:width .3s}.side-deck p{font-size:10px;color:var(--muted);line-height:1.8}.side-bottom{margin-top:auto;padding:25px 12px 0}.little-leaf{font-size:30px;color:#97a185}.side-bottom p{font-family:Georgia,"SimSun",serif;font-size:17px;line-height:1.9;letter-spacing:1px;color:#76806c}.free-pill{font-size:10px;border:1px solid #cfd8c8;padding:5px 10px;border-radius:15px;display:inline-block;color:#718165;margin-bottom:20px}.side-bottom button{display:block;font-size:10px}.workspace{margin-left:232px}.topbar{height:76px;border-bottom:1px solid var(--line);display:flex;justify-content:space-between;align-items:center;padding:0 48px}.breadcrumb{font-size:11px;color:#91958c}.breadcrumb span{margin:0 12px;color:#b4b7ac}.breadcrumb b{font-weight:400;color:#53604f}.top-actions{display:flex;align-items:center;gap:22px}.saved{font-size:10px;color:#829276;letter-spacing:.3px}.icon-button{border:0;background:none;font-size:22px;padding:5px 9px;color:#6e7867}main{max-width:1320px;margin:auto;padding:39px 48px 22px}.page-heading{display:flex;align-items:center;justify-content:space-between;margin-bottom:30px}.page-heading h1{font-family:Georgia,"SimSun",serif;font-size:31px;letter-spacing:2px;font-weight:500;margin:12px 0 12px}.page-heading p{font-size:11px;color:#8b9085;letter-spacing:.8px;margin:0}.day-tag{font-size:10px;color:#979d8e;line-height:2.2;text-align:right}.day-tag strong{display:block;font-size:12px;font-weight:400;color:#6b7863}.deckbar{display:flex;align-items:center;gap:18px;border:1px solid var(--line);background:#f9f8f2;padding:14px 20px;border-radius:10px;font-size:11px;color:#8d9486}.deckbar select{border:0;background:transparent;color:#445641;font-size:12px;font-weight:600;max-width:300px;padding:5px 20px 5px 0;cursor:pointer}.deckbar .divider{width:1px;height:17px;background:var(--line)}.deckbar>button{margin-left:auto}.text-button{border:0;padding:5px 0;background:none;font-size:11px;color:#859078}.text-button:hover{color:#3c6049}.session-line{display:flex;align-items:center;gap:20px;font-size:10px;color:#88917e;margin:24px 2px 17px}.session-line>span{display:flex;align-items:center;gap:9px;white-space:nowrap}.session-line b{font-weight:500}.session-line #roundPosition{color:#9caa8e;margin-left:7px;font-variant-numeric:tabular-nums}.live-dot{width:5px;height:5px;background:#7b956a;border-radius:50%;display:inline-block}.round-track{flex:1;height:3px}.learning-layout{display:grid;grid-template-columns:minmax(0,1.65fr) minmax(275px,1fr);gap:22px;align-items:start}.panel{border:1px solid var(--line);border-radius:14px;background:var(--paper);box-shadow:0 7px 24px #354b3311}.exercise{padding:27px 28px 0}.card-top{display:flex;justify-content:space-between;align-items:center}.card-top .eyebrow{letter-spacing:1.3px;font-size:9px}.tag{background:#eef1e7;color:#859173;border:1px solid #e2e8d7;border-radius:5px;padding:5px 9px;font-size:10px}.prompt{margin:29px 0 25px}.prompt h2{font-family:Georgia,"SimSun",serif;font-size:32px;line-height:1.45;font-weight:600;margin:0 0 12px;letter-spacing:1px}.prompt p{font-size:10px;line-height:1.8;color:#9b9f94;margin:0}.field-label{display:block;font-size:11px;color:#7e8976;margin-bottom:9px}.answer-wrap{position:relative}input{border:1px solid #dce2d3;background:#fcfdf8;border-radius:7px;padding:13px 15px;width:100%;color:#364b3b;outline:0}input:focus{border-color:#8aa17d;box-shadow:0 0 0 3px #849a7810}.answer-wrap input{font-size:20px;padding:13px 110px 13px 15px;height:56px;letter-spacing:.5px}.answer-wrap 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span{display:block}.answer-actions{display:flex;gap:14px;align-items:center;margin:23px 0}.primary,.secondary{border:0;border-radius:7px;padding:13px 20px;font-size:12px;line-height:1.3;display:inline-flex;align-items:center;justify-content:center;gap:25px;background:var(--accent);color:#fff;transition:background .15s}.primary:hover{background:#3d5a48}.primary span{font-size:15px;color:#b6c8af}.secondary{background:#edf1e8;color:#5d7551;border:1px solid #dbe3d4;padding:11px 15px}.answer-actions>.text-button{font-size:10px}.exercise-foot{margin:0 -28px;display:flex;justify-content:space-between;gap:10px;padding:15px 27px;border-top:1px solid #eceee3;background:#fafbf5;border-radius:0 0 14px 14px;font-size:9px;color:#a0aa93}.feedback{font-size:12px;margin-top:16px;padding:13px 14px;line-height:1.9;border-radius:7px;background:#edf3e7;color:#536f45}.feedback.error{background:var(--red-bg);color:var(--red)}.feedback .diff{font-size:17px;letter-spacing:1px;font-family:Consolas,monospace;margin-top:5px}.diff del{color:#b35c49;background:#f6dad1;text-decoration:line-through}.diff ins{color:#5a7e47;background:#e2edd8;text-decoration:none}.right-column{min-width:0}.learning-panel{padding:26px 24px}.intro-title{font-family:Georgia,"SimSun",serif;font-size:23px;font-weight:500;line-height:1.7;margin:18px 0 12px;letter-spacing:1px}.intro-copy{font-size:11px;line-height:2.1;color:#989f8e;margin:0}.mini-stats{display:grid;grid-template-columns:repeat(3,1fr);gap:10px;border-top:1px solid var(--line);border-bottom:1px solid var(--line);margin:25px 0;padding:18px 0;text-align:center}.mini-stats b{display:block;font-family:Georgia,serif;font-size:27px;font-weight:400;color:#5d7352}.mini-stats span{display:block;font-size:9px;color:#9ca58f;margin-top:8px}.steps{list-style:none;margin:0;padding:0}.steps li{display:flex;gap:12px;font-size:10px;color:#8e9982;line-height:1.9;margin:13px 0}.steps li i{display:flex;align-items:center;justify-content:center;flex-shrink:0;width:20px;height:20px;border:1px solid #e0e6d6;border-radius:50%;font-size:9px;font-style:normal;color:#94a086}.steps b{display:block;font-weight:500;color:#6d7e5e}.panel-note{font-size:9px;background:#f3f5ed;padding:12px 13px;border-radius:6px;color:#9da78f;line-height:1.9;margin-top:23px}.review-tip{display:flex;gap:11px;padding:21px 9px;color:#8b977e}.review-tip>span{font-size:22px;color:#9eae8d}.review-tip b{font-size:10px;font-weight:500}.review-tip p{font-size:9px;line-height:2;color:#a3ac98;margin:7px 0 0}.page-footer{display:flex;align-items:center;justify-content:space-between;gap:15px;color:#a6ae9a;font-size:9px;margin:25px 1px 0}.word-heading{display:flex;justify-content:space-between;align-items:center;gap:10px}.word-heading h2{font-family:Georgia,serif;font-size:27px;word-break:break-word;font-weight:400;margin:13px 0}.article{font-size:17px;color:#91a181}.play{border:1px solid 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0}.grammar-core{font-size:12px;color:#6d805f;line-height:1.9}.grammar-detail,.source-detail{font-size:10px;line-height:1.9;color:#96a188;margin-top:15px}.grammar-detail summary,.source-detail summary{cursor:pointer}.grammar-detail table{border-collapse:collapse;width:100%;margin:8px 0;color:#6a805b}.grammar-detail td{padding:5px;border-bottom:1px solid #e9eddf;font-size:11px}.source-detail pre{white-space:pre-wrap;max-height:220px;overflow:auto;font-size:10px;overflow-wrap:anywhere}.pending-note{font-size:9px;color:#a29b7e;line-height:1.9;background:#f7f4e9;padding:9px 11px;border-radius:6px;margin-top:16px}.notice{background:#edeede;border:1px solid #daddc5;padding:12px 16px;border-radius:7px;font-size:12px;line-height:1.8;margin-bottom:20px}dialog{border:1px solid #dce2d2;border-radius:15px;background:var(--paper);color:var(--ink);padding:27px;max-width:620px;width:calc(100% - 30px);max-height:85vh;overflow:auto;box-shadow:0 20px 70px #25341e30}dialog::backdrop{background:#39463166;backdrop-filter:blur(3px)}.dialog-heading{display:flex;justify-content:space-between;align-items:center}.dialog-heading h2{font-size:20px;font-weight:500;margin:0}dialog p{font-size:12px;color:#8a967e;line-height:2}dialog hr{border:0;border-top:1px solid var(--line);margin:22px 0}.button-row{display:flex;gap:12px;flex-wrap:wrap}.file-label{cursor:pointer}.muted{color:#a1aa94!important;font-size:11px!important}.check-label{display:flex;gap:10px;align-items:center;font-size:13px}.check-label input{width:16px}.coverage-grid{display:grid;grid-template-columns:1fr 1fr;gap:10px;margin:20px 0}.coverage-grid div{background:#f1f4e9;border-radius:7px;padding:12px;font-size:10px;color:#89977b}.coverage-grid b{display:block;font-size:23px;font-weight:400;margin-bottom:5px}.round-results{max-height:260px;overflow:auto;margin:20px 0;font-size:12px}.round-results>div{display:flex;justify-content:space-between;padding:9px 0;border-bottom:1px solid var(--line)}
@media(min-width:1500px){main{padding-top:46px}.canvas-wrap{height:215px;background-size:100% 43px}.prompt{margin:36px 0 28px}.prompt h2{font-size:36px}.exercise{padding-top:31px}}
@media(max-width:1150px){.sidebar{width:190px;padding:30px 18px}.workspace{margin-left:190px}main{padding:30px 26px}.topbar{padding:0 26px}.learning-layout{grid-template-columns:minmax(0,1.5fr) minmax(245px,1fr);gap:15px}.exercise{padding:23px 20px 0}.exercise-foot{margin:0 -20px;padding:14px 20px}.learning-panel{padding:23px 18px}.specials>span{display:none}.ink-toolbar small{display:none}.prompt h2{font-size:29px}.answer-actions{gap:10px}.answer-actions .primary{padding:13px 15px}.answer-actions>.text-button{font-size:9px}}
@media(max-width:920px){.sidebar{width:76px;padding:24px 12px;align-items:center}.brand>span:last-child,.side-label,.side-deck,.side-bottom,.nav b{display:none}.sidebar nav{margin-top:35px}.nav{font-size:0;display:flex;justify-content:center;padding:14px 13px}.nav span{font-size:23px}.workspace{margin-left:76px}.page-heading h1{font-size:27px}.page-heading .eyebrow{font-size:9px}.topbar{height:65px}}
@media(max-width:730px){.learning-layout{grid-template-columns:1fr}.right-column{display:flex;flex-direction:column}.learning-panel{padding:23px}.intro-title{margin:8px 0}.mini-stats{margin:17px 0}.steps{display:none}.panel-note{margin-top:15px}.review-tip{padding:15px 5px}.deckbar{gap:11px;padding:11px 14px}.deckbar>label,.deckbar .divider{display:none}.deckbar select{max-width:220px}.deckbar #deckMeta{font-size:9px}.day-tag{display:none}.page-footer{line-height:1.8;align-items:start}.page-footer>span:first-child{white-space:nowrap}.prompt{margin:24px 0}.canvas-wrap{height:185px}.learning-panel .intro-copy{font-size:11px}.learning-panel{box-shadow:none}.top-actions{gap:10px}}
@media(max-width:480px){.sidebar{display:none}.workspace{margin-left:0}.topbar{padding:0 20px;height:57px}main{padding:27px 17px 20px}.page-heading{margin-bottom:23px}.page-heading h1{font-size:26px}.page-heading p{font-size:10px}.saved{font-size:9px}.deckbar select{max-width:190px;font-size:11px}.deckbar #deckMeta{display:none}.session-line{gap:12px;margin-top:20px}.exercise{padding:21px 18px 0}.exercise-foot{margin:0 -18px;padding:14px 18px;font-size:8px}.prompt h2{font-size:30px}.answer-wrap input{padding-right:15px}.answer-wrap>span{display:none}.ink-toolbar{padding:10px}.ink-toolbar>div{gap:10px}.answer-actions{justify-content:space-between}.answer-actions>.text-button{font-size:9px}.primary{font-size:11px;padding:13px 16px;gap:15px}.ink-foot{font-size:8px;line-height:1.8}.page-footer{font-size:8px}.breadcrumb{font-size:10px}}

/* Reading sizes and contrast: keep instructions comfortable during long desktop sessions. */
body{font-size:14px}.topbar{height:66px}main{padding-top:29px}.page-heading{margin-bottom:23px}.page-heading p{font-size:12px;color:#76816f}.side-label{font-size:12px;color:#78826f}.nav{font-size:14px}.side-deck p{font-size:11px;color:#737e69}.side-bottom button{font-size:11px}.breadcrumb{font-size:12px}.saved{font-size:11px}.eyebrow{font-size:11px;color:#76836c}.deckbar{font-size:12px;color:#78856d}.deckbar select{font-size:13px}.text-button{font-size:12px;color:#6c7f60}.session-line{font-size:11px;margin-top:20px}.exercise{padding-top:24px}.card-top .eyebrow{font-size:10px}.tag{font-size:11px;color:#71815f}.prompt{margin:24px 0 21px}.prompt p{font-size:12px;color:#7e8874}.field-label{font-size:12px;color:#728167}.specials>span{font-size:10px;color:#808d73}.ink-toolbar b{font-size:12px;color:#6d7e5c}.ink-toolbar small{font-size:10px;color:#859376}.ink-toolbar button{font-size:11px}.canvas-wrap{height:165px;background-size:100% 41px}#inkPlaceholder{color:#96a485}#inkPlaceholder>span{font-size:10px;color:#8a987a}.ink-foot{font-size:10px;color:#748568}.pen-diagnostics{font-size:10px;color:#879577}.answer-actions{margin:20px 0}.answer-actions>.text-button{font-size:11px}.exercise-foot{font-size:10px;color:#81906e}.intro-copy{font-size:12px;color:#7e8c71}.mini-stats span{font-size:11px;color:#7c8c6c}.steps li{font-size:12px;color:#7d8e6d}.steps b{color:#637a52}.panel-note{font-size:11px;color:#7e9069}.review-tip b{font-size:12px;color:#758963}.review-tip p{font-size:11px;color:#849675}.page-footer{font-size:10px;color:#859773}.word-zh{font-size:13px;color:#7d8b6e}.section-label{font-size:11px;color:#82946f}.word-plural,.content-zh{font-size:12px;color:#7c8c6c}.content-de{font-size:16px}.content-example{font-size:13px}.grammar-core{font-size:14px}.grammar-detail,.source-detail{font-size:12px;color:#7f906d}.grammar-detail td{font-size:13px}.pending-note{font-size:11px;color:#8a815f}.muted{font-size:12px!important;color:#879474!important}.coverage-grid div{font-size:12px;color:#74885d}.page-heading h1{font-weight:600}.learning-panel .intro-title{font-size:25px}dialog p{font-size:13px;color:#7e8d6d}
@media(max-width:1150px){.answer-actions>.text-button{font-size:10px}.ink-toolbar small{display:none}.specials>span{display:none}}
@media(max-width:920px){.nav{font-size:0}.page-heading .eyebrow{font-size:10px}}
@media(max-width:480px){main{padding:24px 17px 20px}.prompt p{font-size:11px}.page-heading p{font-size:11px}.session-line{font-size:10px}.canvas-wrap{height:180px}.saved{font-size:10px}.ink-foot{font-size:9px}.answer-actions>.text-button{font-size:10px}.exercise-foot{font-size:9px}.page-footer{font-size:9px}}
.mobile-nav{display:none}
@media(max-width:480px){.mobile-nav{display:flex;gap:8px;margin:0 0 16px}.mobile-nav .nav{width:auto;margin:0;font-size:11px;padding:9px 15px;flex:1;white-space:nowrap}}

.test-banner{padding:8px 18px;text-align:center;font:12px/1.5 system-ui;background:#eef2ff;color:#334155}.test-banner a{margin-left:10px;color:#334bc1}