/* Study shelves: subject index, readable notes, and source-linked video segments. */
.youth-page{--y-ink:#223b58;--y-muted:#64768c;--y-accent:#456b58;--y-paper:#fff;--y-canvas:#f3f6fa;--y-soft:#eef4f0;--y-line:#dce4ed;--y-teal:var(--y-accent);--ink:var(--y-ink);--ink-2:#50667e;--muted:var(--y-muted);--mist:var(--y-canvas);--line:var(--y-line);--line-strong:#d3dde9;--medical:var(--y-accent);--font-body:"PingFang SC","Microsoft YaHei",system-ui,sans-serif;--font-display:var(--font-body);background:var(--y-canvas);color:var(--y-ink);font-family:var(--font-body)}
body.clinical-app.youth-page{background-image:none!important}
.youth-page .navbar{position:sticky;top:0;z-index:100;background:#ffffffed;border-bottom:1px solid var(--y-line);box-shadow:none;backdrop-filter:blur(12px)}
.youth-page .user-info{display:flex;gap:8px}.youth-page button,.youth-page input,.youth-page select{font:inherit}.youth-page button{cursor:pointer}.youth-page button:disabled{opacity:.55;cursor:wait}.youth-page [hidden]{display:none!important}
.youth-page :is(a,button,input,select,summary):focus-visible{outline:3px solid #617eaa;outline-offset:3px}
.youth-shell{width:min(1260px,calc(100% - 64px));margin:42px auto 0;padding-bottom:64px}.youth-page-head{padding:0 0 30px;border-bottom:1px solid var(--y-line);margin-bottom:30px}.youth-heading{display:flex;align-items:center;gap:17px}.youth-library-symbol{display:grid;place-items:center;width:52px;height:57px;color:var(--y-accent);background:#e6eee9;border-radius:9px 9px 9px 2px}.youth-library-symbol svg{width:34px;height:34px;transform:translateX(-2px)}.youth-kicker{font-size:11px;font-weight:600;letter-spacing:.12em;color:var(--y-muted);margin:0 0 5px}.youth-page-head h1{font-family:"Songti SC","STSong","Noto Serif SC",serif;font-weight:700;font-size:34px;letter-spacing:.03em;line-height:1.3;margin:0}.youth-page-description{font-size:14px;line-height:1.8;color:var(--y-muted);margin:16px 0 0 69px}
.youth-library-layout{display:grid;grid-template-columns:200px minmax(0,1fr);gap:38px;align-items:start}.youth-sidebar{position:sticky;top:103px;min-width:0}.youth-sidebar-section h2{font-size:12px;font-weight:650;color:var(--y-muted);margin:0 0 13px}.youth-topics{display:flex;flex-direction:column;gap:4px}.youth-topic{display:flex;align-items:center;justify-content:space-between;gap:12px;min-height:42px;padding:10px 13px;border:1px solid transparent;border-radius:7px;background:transparent;text-align:left;color:var(--y-muted);font-size:13px;line-height:1.55}.youth-topic>span{overflow-wrap:anywhere}.youth-topic small{font-family:"SFMono-Regular",Consolas,monospace;font-size:11px;font-weight:400;opacity:.75}.youth-topic:hover{background:#e9eef4;color:var(--y-ink)}.youth-topic.is-selected{background:var(--y-paper);border-color:var(--y-line);color:var(--y-ink);font-weight:650;box-shadow:0 2px 3px #223b5804}.youth-topic.is-selected:before{content:"";height:15px;width:3px;background:var(--y-accent);border-radius:2px;flex:0 0 auto;margin-left:-6px;margin-right:-5px}.youth-topic.is-selected>span{margin-right:auto}
.youth-library-about{border-top:1px solid var(--y-line);margin-top:28px;padding:22px 11px 0}.youth-curator-label{display:flex;align-items:center;gap:7px;color:var(--y-ink);font-size:12px;font-weight:650;margin:0 0 9px}.youth-curator-label span{color:var(--y-accent);font-size:16px}.youth-library-about>p:not(.youth-curator-label),.youth-private-note{font-size:11px;color:var(--y-muted);line-height:1.9;margin:0}.youth-library-about>span{display:block;font-size:10px;color:var(--y-muted);margin-top:12px}.youth-private-note{margin:22px 11px 0;padding-top:18px;border-top:1px solid var(--y-line)}
.youth-library{min-width:0;scroll-margin-top:95px}.youth-section-head{display:flex;justify-content:space-between;align-items:center;gap:16px;margin:0 0 21px}.youth-section-head h2{display:flex;align-items:center;gap:11px;margin:0;color:var(--y-ink);font-size:18px;font-weight:650}.youth-count{display:inline-grid;place-items:center;min-width:26px;padding:2px 6px;border-radius:5px;background:#e6ecf3;font:500 11px/1.6 "SFMono-Regular",Consolas,monospace;color:var(--y-muted)}.youth-section-head .quiet-button{display:inline-flex;align-items:center;gap:7px;min-height:38px;font-size:12px;padding:8px 12px;color:var(--y-ink);border:1px solid var(--y-line);border-radius:7px;background:var(--y-paper);box-shadow:none}.youth-section-head .quiet-button span{font-size:17px;line-height:1}
.youth-controls{display:grid;grid-template-columns:minmax(0,1fr) 175px;gap:15px;padding:18px 20px;background:#e9eef5;border:1px solid #e0e7f0;border-radius:10px}.youth-local-search,.youth-learning-filter{display:flex;flex-direction:column;gap:7px;min-width:0}.youth-control-label{font-size:11px;color:var(--y-muted);font-weight:600}.youth-search-field{position:relative;display:block}.youth-search-field svg{position:absolute;top:12px;left:12px;width:18px;height:18px;color:#8190a1;pointer-events:none}.youth-local-search input,.youth-learning-filter select{width:100%;min-height:43px;border:1px solid #d3dde9;border-radius:6px;background:var(--y-paper);color:var(--y-ink);font-size:13px;padding:10px 12px;box-sizing:border-box;box-shadow:none}.youth-local-search input{padding-left:39px}.youth-local-search input::placeholder{color:#8996a7}.youth-learning-filter select{padding-right:24px}.youth-results-head{display:flex;justify-content:space-between;align-items:center;gap:14px;min-height:52px}.youth-library-status{font-size:11px;line-height:1.8;color:var(--y-muted);margin:13px 0}.youth-text-button{background:transparent;border:0;padding:9px 0;min-height:40px;font-size:11px;color:var(--y-accent);white-space:nowrap;text-decoration:underline;text-underline-offset:3px}.youth-feedback-status{padding:11px 14px;font-size:12px;line-height:1.7;color:var(--y-ink);background:#e7eef9;border-left:3px solid #6b87b2;border-radius:3px;margin:0 0 16px}.youth-feed{display:flex;flex-direction:column;gap:17px}
.youth-entry{background:var(--y-paper);border:1px solid var(--y-line);border-radius:10px;min-width:0;overflow:hidden}.youth-entry-main{padding:24px 25px 20px}.youth-entry-heading{display:flex;justify-content:space-between;align-items:flex-start;gap:15px}.youth-entry h3{font-size:19px;line-height:1.65;letter-spacing:.005em;margin:0;overflow-wrap:anywhere;font-weight:650}.youth-entry h3 a{color:var(--y-ink);text-decoration:none}.youth-entry h3 a:hover{text-decoration:underline;text-decoration-thickness:1px;text-underline-offset:4px}.youth-completed-label{display:inline-flex;align-items:center;gap:4px;flex:0 0 auto;font-size:10px;color:var(--y-accent);background:var(--y-soft);border:1px solid #d9e7dd;border-radius:4px;padding:4px 6px;margin-top:3px;white-space:nowrap}.youth-video-meta{display:flex;flex-wrap:wrap;align-items:center;gap:5px 14px;margin:9px 0 19px;font-size:11px;color:var(--y-muted);line-height:1.8}.youth-video-meta>span{display:inline-flex;gap:5px;align-items:center}.youth-video-meta time{color:#8995a4}.youth-video-meta .youth-platform-label{color:#7b667b}.youth-entry-summary{font-size:13px;line-height:1.95;color:#50667e;margin:0 0 16px;white-space:pre-wrap;overflow-wrap:anywhere}.youth-recommendation{display:flex;gap:12px;align-items:flex-start;padding:12px 14px;background:#f3f6fa;border-radius:5px;margin-bottom:18px}.youth-recommendation>span{font-size:10px;color:var(--y-muted);flex:0 0 auto;margin-top:3px}.youth-recommendation p{font-size:12px;color:#536981;line-height:1.9;margin:0;white-space:pre-wrap;overflow-wrap:anywhere}.youth-entry-tags{display:flex;flex-wrap:wrap;gap:6px;margin:0}.youth-entry-tags span{font-size:10px;line-height:1.6;color:#62778d;padding:3px 7px;border:1px solid #e2e9f1;border-radius:4px;background:#fafbfd}
.youth-study-guide{margin:19px 0 0;border-top:1px solid #e8edf3;padding-top:14px;font-size:12px;line-height:1.9;color:var(--y-ink)}.youth-study-guide summary{display:flex;align-items:center;gap:8px;cursor:pointer;list-style:none;font-weight:600;min-height:28px}.youth-study-guide summary::-webkit-details-marker{display:none}.youth-study-guide summary:before{content:"+";display:grid;place-items:center;width:18px;height:18px;border:1px solid var(--y-line);border-radius:4px;color:var(--y-accent);font-size:14px;font-weight:400}.youth-study-guide[open] summary:before{content:"−"}.youth-study-guide-body{padding:14px 0 0 27px}.youth-study-guide h4{font-size:11px;margin:14px 0 6px;color:var(--y-muted);font-weight:650}.youth-study-guide h4:first-child{margin-top:0}.youth-study-guide ul{margin:0;padding:0 0 0 17px}.youth-study-guide li{padding-left:3px;margin-bottom:4px;overflow-wrap:anywhere}.youth-guide-audience{margin:0 0 12px;font-size:11px;color:var(--y-muted)}.youth-guide-audience b{font-weight:500;margin-right:7px}.youth-timeline{display:flex;flex-direction:column;gap:7px;margin:7px 0 12px}.youth-timeline a{display:flex;align-items:baseline;gap:12px;min-height:34px;text-decoration:none;color:var(--y-ink);padding:4px 0}.youth-timeline a:hover>span:last-child{text-decoration:underline;text-underline-offset:3px}.youth-timeline .youth-timestamp{display:inline-block;flex:0 0 auto;min-width:94px;font:500 10px/1.8 "SFMono-Regular",Consolas,monospace;color:var(--y-accent);padding:4px 7px;border-radius:4px;background:var(--y-soft)}.youth-guide-source{font-size:11px;line-height:1.8;color:var(--y-muted);margin:12px 0 0}
.youth-entry-foot{display:flex;align-items:center;justify-content:space-between;gap:16px;padding:13px 25px;border-top:1px solid #e8edf3;background:#fcfdfe}.youth-basis{font-size:10px;line-height:1.8;color:var(--y-muted)}.youth-watch{display:inline-flex;align-items:center;gap:14px;justify-content:center;min-height:38px;padding:8px 14px;border:1px solid #d2ded5;border-radius:6px;background:var(--y-soft);color:var(--y-accent);font-size:12px;font-weight:600;text-decoration:none;white-space:nowrap}.youth-watch:hover{background:#e2ece5}.youth-watch span{font-size:15px}.youth-learning-actions{display:flex;align-items:center;gap:6px;padding:10px 18px;border-top:1px solid #edf1f6;background:#fff}.youth-learning-actions button{display:inline-flex;align-items:center;justify-content:center;gap:5px;min-height:38px;font-size:11px;color:var(--y-muted);padding:7px 10px;border:1px solid transparent;background:transparent;border-radius:5px}.youth-learning-actions button:hover{background:#f3f6fa;color:var(--y-ink)}.youth-learning-actions button[aria-pressed=true]{border-color:#cbded1;background:var(--y-soft);color:var(--y-accent)}.youth-learning-actions .youth-private-label{margin-left:auto;color:#8a96a4;font-size:10px}.youth-empty{padding:50px 26px;border:1px solid var(--y-line);border-radius:10px;background:#ffffffb8;text-align:center}.youth-empty h3{font-size:17px;font-weight:600;margin:0 0 10px;line-height:1.7}.youth-empty p{font-size:13px;line-height:1.9;color:var(--y-muted);margin:0 auto;max-width:480px}.youth-empty button{margin-top:20px}.youth-source-note{margin:24px 1px 0;font-size:10px;line-height:1.9;color:var(--y-muted)}.youth-loading{border:1px solid var(--y-line);border-radius:10px;padding:27px;background:#fff}.youth-loading span{display:block;height:12px;background:#ecf0f6;border-radius:3px;margin-bottom:17px;width:77%}.youth-loading span:first-child{width:58%;height:18px}.youth-loading span:last-child{width:42%;margin-bottom:0}
@media(min-width:1450px){.youth-shell{width:min(1340px,calc(100% - 96px))}.youth-library-layout{grid-template-columns:220px minmax(0,1fr);gap:48px}.youth-entry-main{padding:27px 30px 23px}.youth-entry-foot{padding-inline:30px}.youth-learning-actions{padding-inline:23px}}
@media(max-width:980px){.youth-shell{width:calc(100% - 40px);margin-top:30px}.youth-library-layout{grid-template-columns:165px minmax(0,1fr);gap:24px}.youth-controls{padding:15px;grid-template-columns:minmax(0,1fr) 145px;gap:12px}.youth-entry-main{padding:21px}.youth-entry-foot{padding-inline:21px}.youth-learning-actions{padding-inline:14px}.youth-private-label{display:none}.youth-entry h3{font-size:18px}}
@media(max-width:720px){.youth-shell{width:calc(100% - 32px);margin-top:26px;padding-bottom:35px}.youth-page-head{margin-bottom:23px;padding-bottom:22px}.youth-heading{gap:13px}.youth-library-symbol{width:44px;height:49px}.youth-library-symbol svg{width:30px;height:30px}.youth-page-head h1{font-size:29px}.youth-kicker{font-size:10px}.youth-page-description{margin:14px 0 0;font-size:12px}.youth-library-layout{display:block}.youth-sidebar{position:static;margin-bottom:25px}.youth-sidebar-section h2{font-size:11px;margin-bottom:10px}.youth-topics{flex-direction:row;flex-wrap:wrap;gap:6px}.youth-topic{min-height:39px;padding:8px 11px;border-color:var(--y-line);font-size:11px;background:#f7f9fc;gap:9px}.youth-topic.is-selected{background:var(--y-ink);color:#fff;border-color:var(--y-ink)}.youth-topic.is-selected:before{display:none}.youth-library-about,.youth-private-note{display:none}.youth-section-head{margin-bottom:16px}.youth-section-head h2{font-size:17px}.youth-section-head .quiet-button{font-size:11px;padding:7px 10px}.youth-controls{grid-template-columns:minmax(0,1fr) 135px;gap:10px;padding:13px;border-radius:8px}.youth-control-label{font-size:10px}.youth-local-search input,.youth-learning-filter select{font-size:12px;min-height:43px}.youth-search-field svg{left:10px}.youth-local-search input{padding-left:34px;padding-right:8px}.youth-results-head{min-height:48px}.youth-library-status{font-size:10px}.youth-text-button{font-size:10px}.youth-entry-main{padding:19px 18px 18px}.youth-entry h3{font-size:17px;line-height:1.7}.youth-entry-heading{gap:9px}.youth-completed-label{font-size:9px;padding:3px 5px}.youth-video-meta{font-size:10px;gap:4px 10px;margin-bottom:15px}.youth-entry-summary{font-size:12px}.youth-recommendation{gap:8px;padding:10px 11px;flex-direction:column}.youth-recommendation>span{font-size:10px;margin-top:0}.youth-recommendation p{font-size:11px}.youth-study-guide{font-size:11px}.youth-study-guide-body{padding-left:0}.youth-timeline a{gap:10px}.youth-timeline .youth-timestamp{min-width:87px;font-size:9px}.youth-entry-foot{padding:12px 18px;gap:10px}.youth-basis{font-size:9px}.youth-watch{font-size:11px;padding:7px 10px;gap:10px;min-height:38px}.youth-learning-actions{padding:9px 10px;gap:2px}.youth-learning-actions button{font-size:10px;padding:7px 8px;min-height:40px}.youth-source-note{font-size:10px}.youth-empty{padding:37px 20px}.youth-profile{display:none!important}}
@media(max-width:390px){.youth-controls{grid-template-columns:minmax(0,1fr)}.youth-learning-filter{display:grid;grid-template-columns:auto minmax(0,1fr);align-items:center;gap:15px}.youth-entry-heading{display:block}.youth-completed-label{margin-top:8px}.youth-entry-foot{align-items:flex-start}.youth-basis{max-width:48%}.youth-learning-actions button{padding-inline:7px}}
@media(prefers-reduced-motion:reduce){.youth-page *{scroll-behavior:auto!important;animation:none!important;transition:none!important}}