.study-page,.study-detail{--study-green:#153f35;--study-ink:#213a32;--study-muted:#6d7b72;--study-line:#dde5dc}.study-hero{background:linear-gradient(125deg,#153f35,#245446);color:#fff;padding:36px 40px;border-radius:24px;margin-bottom:22px}.study-hero .eyebrow{color:#bdceaa}.study-hero h1{font-size:clamp(30px,4vw,43px);margin:12px 0}.study-hero p{color:#dce7da;line-height:1.8;margin-bottom:24px}.study-intents{display:grid;grid-template-columns:repeat(3,1fr);gap:12px}.study-intents button{border:1px solid #6b8a7a;background:#ffffff08;color:#f3f6eb;padding:18px;text-align:left;border-radius:14px;cursor:pointer}.study-intents button strong,.study-intents button span{display:block}.study-intents strong{font-size:19px;margin-bottom:6px}.study-intents span{font-size:13px;color:#d0dfcc}.study-intents button.active{background:#edf1df;color:#183f33;border-color:#edf1df}.study-intents button.active span{color:#58694b}.study-shelves{display:flex;gap:10px;flex-wrap:wrap;margin:24px 0}.study-shelves button{border:1px solid var(--study-line);border-radius:100px;padding:10px 17px;background:#fff;color:var(--study-ink);cursor:pointer}.study-shelves button.active{background:#153f35;color:white;border-color:#153f35}.study-search{display:grid;grid-template-columns:minmax(180px,2fr) repeat(3,minmax(105px,1fr)) auto;gap:10px;align-items:end;margin:20px 0}.study-search label{display:grid;gap:7px;margin:0;font-size:12px;color:var(--study-muted)}.study-search input,.study-search select{width:100%;min-width:0;margin:0;background:white;border:1px solid var(--study-line);padding:11px;border-radius:9px;font-size:14px}.study-search .btn{height:44px}.study-topic-banner{display:flex;justify-content:space-between;align-items:center;gap:18px;background:#edf0e5;border:1px solid #e0e4d3;border-radius:16px;padding:22px 25px;margin:26px 0}.study-topic-banner small{letter-spacing:.08em;color:#657758}.study-topic-banner h2{font-size:22px;margin:7px 0}.study-topic-banner p{font-size:14px;line-height:1.6;color:#63705f;margin:0}.study-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:20px;margin:18px 0 30px}.study-card{display:flex;flex-direction:column;border:1px solid #e1e6df;border-radius:18px;overflow:hidden;background:#fff;box-shadow:0 6px 18px #153f3506}.study-card-open{padding:0;border:0;background:none;color:inherit;text-align:left;cursor:pointer;display:block;width:100%;flex:1}.study-card-open:hover h3{text-decoration:underline;text-underline-offset:4px}.study-thumb{position:relative;background:#132637;aspect-ratio:16/9;overflow:hidden}.study-thumb img{display:block;width:100%;height:100%;object-fit:cover}.study-play{position:absolute;left:16px;bottom:12px;background:#ffffffdf;color:#23463b;border-radius:100px;padding:8px 12px}.study-duration{position:absolute;bottom:12px;right:12px;background:#132637c7;color:white;padding:5px 8px;border-radius:6px;font-size:12px}.study-text-cover{background:linear-gradient(145deg,#e6ebe0,#f1eee5);aspect-ratio:16/9;padding:22px;display:flex;flex-direction:column;justify-content:space-between;color:#476448}.study-text-cover strong{font-size:28px;font-family:serif}.study-text-cover span,.study-text-cover small{font-size:12px}.study-card-body{padding:20px}.study-card h3{font-size:19px;line-height:1.6;margin:9px 0}.study-card p{font-size:14px;line-height:1.7;color:#6d796f;margin:0}.study-card-foot{display:flex;align-items:center;justify-content:space-between;padding:12px 20px;border-top:1px solid #edf0ea;font-size:12px;color:#687b66}.study-coming{border-top:1px solid #dee5d9;padding:20px 0;color:#70816e;font-size:14px;line-height:1.8}.study-home{margin-bottom:25px}.study-home h2{margin-top:6px}.study-home-actions{display:flex;gap:10px;flex-wrap:wrap;margin:15px 0}.study-resume-list{display:grid;gap:10px}.study-resume-list>button{width:100%;border:1px solid #e1e8db;border-radius:13px;background:#f6f7f1;padding:16px;display:flex;align-items:center;gap:14px;text-align:left;cursor:pointer}.study-resume-list strong,.study-resume-list small{display:block}.study-resume-list small{color:#798671;margin-bottom:5px}.study-resume-list strong{line-height:1.55;font-size:15px}.study-resume-icon{width:40px;height:40px;border-radius:10px;display:grid;place-items:center;background:#dee6d7;color:#284f37;flex-shrink:0}.study-resume-list>button>span:last-child{margin-left:auto}.study-review-line{margin:18px 0 0;font-size:14px;color:#6a7963}.study-backline{display:flex;align-items:center;gap:14px;flex-wrap:wrap;margin:4px 0 27px}.study-backline>span{font-size:12px;color:#6b7a6e}.study-backline>button:last-child{margin-left:auto}.study-detail>header h1{font-size:clamp(25px,3.5vw,36px);line-height:1.55;margin:12px 0}.study-lead{font-size:17px;color:#6b776d;line-height:1.9}.study-player{background:#0d1a26;border-radius:18px;overflow:hidden;margin-top:25px;aspect-ratio:16/9}.study-player video{display:block;width:100%;height:100%;object-fit:contain}.study-player-status{display:flex;justify-content:space-between;gap:15px;align-items:center;margin:12px 0;font-size:13px;color:#768270}.study-personal-actions{display:flex;gap:10px;flex-wrap:wrap;margin:20px 0 27px}.study-reading-grid{display:grid;grid-template-columns:minmax(0,1.7fr) minmax(270px,1fr);gap:24px}.study-reading-grid .card{margin-bottom:20px}.study-chapters h2,.study-reading h2,.study-notes h2,.study-checks h2{font-size:22px}.study-chapters>div{display:grid;gap:0}.study-chapters button{display:flex;align-items:center;gap:16px;border:0;border-bottom:1px solid #e7ece3;background:none;padding:13px 0;text-align:left;width:100%;cursor:pointer;color:#344f3a}.study-chapters time{font-size:13px;min-width:37px;color:#7f8b76;font-variant-numeric:tabular-nums}.study-chapters button span:last-child{margin-left:auto}.study-reading p,.study-source p,.study-checks p{font-size:16px;line-height:1.95;white-space:pre-line;overflow-wrap:anywhere}.study-notes textarea{width:100%;resize:vertical;min-height:125px;max-height:450px;background:#fafbf7;border:1px solid #dce4d6;border-radius:11px;padding:13px;font-size:15px;line-height:1.7}.study-note-item{border-top:1px solid #e5ebdf;padding-top:17px;margin-top:18px}.study-note-item p{font-size:15px;line-height:1.8;white-space:pre-wrap;overflow-wrap:anywhere}.study-note-item small{font-size:11px;color:#87917e}.study-no-notes{padding-top:15px}.study-figure{margin:0 0 20px}.study-figure img{width:100%;display:block;border-radius:12px}.study-figure figcaption{font-size:12px;color:#7b8771;margin:8px}.study-checks details{padding:15px 0;border-bottom:1px solid #e6ecdf}.study-checks summary,.study-source summary{cursor:pointer;font-size:15px;color:#34553e;line-height:1.7}.study-related>button{display:flex;justify-content:space-between;gap:12px;padding:13px 0;text-align:left;border:0;border-bottom:1px solid #e4eadf;background:none;color:#325541;font-size:15px;line-height:1.65;cursor:pointer;width:100%}.study-grid .meta{font-size:11px}.study-detail #study-note-status{font-size:12px}.study-grid button:focus-visible,.study-page button:focus-visible,.study-detail button:focus-visible{outline:3px solid #759365;outline-offset:3px}@media(max-width:1150px){.study-search{grid-template-columns:repeat(3,minmax(0,1fr))}.study-search label:first-child{grid-column:span 2}.study-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.study-reading-grid{grid-template-columns:minmax(0,1fr)}}@media(max-width:600px){.study-hero{padding:24px 20px;border-radius:17px}.study-hero h1{font-size:30px}.study-intents{gap:7px}.study-intents button{padding:13px 8px}.study-intents strong{font-size:15px}.study-intents span{font-size:11px;line-height:1.5}.study-shelves{gap:7px}.study-shelves button{padding:8px 11px;font-size:12px}.study-search{grid-template-columns:repeat(2,minmax(0,1fr))}.study-search label:first-child{grid-column:1/-1}.study-search .btn{width:100%}.study-topic-banner{display:block;padding:19px}.study-topic-banner h2{font-size:20px}.study-topic-banner .btn{margin-top:16px}.study-grid{grid-template-columns:minmax(0,1fr);gap:17px}.study-card-body{padding:17px}.study-card h3{font-size:19px}.study-backline{gap:10px}.study-backline>button:last-child{margin-left:0}.study-detail>header h1{font-size:25px}.study-player{border-radius:10px;margin-top:18px}.study-player-status{align-items:flex-start;font-size:12px}.study-personal-actions .btn{padding:10px 12px;font-size:13px}.study-reading-grid{gap:0}.study-lead{font-size:15px}.study-home .section-head{align-items:flex-start;gap:12px;flex-wrap:wrap}.study-home h2{font-size:22px}}

.nav .record-entry{padding:13px 16px;text-decoration:none;border-radius:8px;color:var(--muted);display:flex;gap:13px;align-items:center}
@media(max-width:700px){.nav .record-entry{flex:1;flex-direction:column;justify-content:center;gap:2px;padding:7px 2px;font-size:10px}}
.study-path-steps{display:grid;grid-template-columns:1fr 1fr;gap:18px;margin-top:22px}.study-path-steps button{display:grid;gap:8px;padding:20px;text-align:left;background:var(--white);color:var(--ink);border:1px solid var(--line);border-radius:14px}.study-path-steps strong{font-size:20px}.study-path-steps small,.study-path-steps span{color:var(--muted)}.study-sequence{display:flex;justify-content:space-between;gap:16px;align-items:center;margin:20px 0}.study-sequence>div{display:flex;gap:10px}.study-player{position:relative;overflow:hidden}.study-player video{aspect-ratio:16/9}.study-watermark{position:absolute;z-index:3;pointer-events:none;max-width:72%;padding:4px 8px;border-radius:5px;background:#0000001c;color:#ffffffb8;text-shadow:0 1px 2px #000c;font-size:13px;line-height:1.4;animation:study-mark-move 37s steps(1,end) infinite}.study-fullscreen{position:absolute;right:12px;top:12px;z-index:4;background:#0008;color:white;border:1px solid #fff5;border-radius:7px;padding:6px 12px}.study-player:fullscreen{display:flex;align-items:center;justify-content:center;background:#000}.study-player:fullscreen video{height:100%;width:100%;object-fit:contain}.study-player video::-webkit-media-controls-fullscreen-button{display:none}.study-player video::-webkit-media-controls-download-button{display:none}@keyframes study-mark-move{0%,100%{left:8%;top:15%}25%{left:39%;top:35%}50%{left:12%;top:66%}75%{left:37%;top:77%}}@media(max-width:700px){.study-path-steps{grid-template-columns:1fr}.study-path-steps strong{font-size:18px}.study-sequence{display:grid}.study-sequence>div{flex-wrap:wrap}.study-watermark{font-size:10px;max-width:62%}}

/* R12 audio guided practice — no video fullscreen/watermark chrome */
.study-audio-cover{background:linear-gradient(145deg,#1e3a45,#2d5650);color:#e8f0ea}
.study-audio-cover strong{color:#f3f8f2}
.study-audio-badge{background:#ffffffdf;color:#1e4a3b}
.study-audio-player{margin-top:22px;border:1px solid #d9e3d6;border-radius:16px;background:#f7f9f4;padding:18px 18px 12px}
.study-audio-player audio{display:none}
.study-audio-panel{display:grid;gap:12px}
.study-audio-times{display:flex;justify-content:space-between;font-variant-numeric:tabular-nums;font-size:13px;color:#667866}
.study-audio-seek{width:100%;accent-color:#153f35}
.study-audio-controls{display:flex;flex-wrap:wrap;gap:8px}
.study-audio-hint{margin:4px 0 0;font-size:12px;line-height:1.6}
@media(max-width:600px){.study-audio-player{padding:14px}.study-audio-controls .btn{padding:8px 10px;font-size:12px}}

/* C2 material-scoped help */
.study-help .r16-material-ref code{font-size:.85em;word-break:break-all}
.study-help .btn{min-height:44px;margin:.35rem .35rem 0 0}
@media (max-width:430px){.study-help .btn{display:block;width:100%;margin:.35rem 0}}

/* K6 可及性：移动视口/粗指针下触控目标 ≥44px（WCAG 2.5.5 / Apple HIG） */
@media (max-width: 767px), (pointer: coarse) {
  .study-page button, .study-page .btn,
  .study-detail button, .study-detail .btn,
  .study-shelves button, .study-personal-actions button,
  .study-audio-controls button { min-height: 44px; }
}