/* Seven-subject extension. All colors come from the shared paper brand tokens. */
.subject-tabs{display:grid;grid-template-columns:repeat(7,minmax(0,1fr));gap:3px}
.subject-tabs button{min-width:54px;white-space:nowrap}
.subject-brief{font-size:13px;line-height:1.8;color:var(--textSecondary);margin:0 0 16px}
.source-label{font-size:12px;line-height:1.8;color:var(--textMuted);margin:0 0 12px}
.source-title{font-family:var(--serif);font-size:26px;font-weight:500;margin:0 0 10px}
.source-question{border-top:1px solid var(--border);margin-top:24px;padding-top:16px}
.source-question h4{font-size:15px;margin:0 0 9px;color:var(--primary)}
.source-question p{margin:0;line-height:1.9}
.source-links{font-size:12px;line-height:2;margin:24px 0 0;color:var(--textMuted)}
.source-links a{text-decoration:underline;text-underline-offset:3px}
.chinese-passage{font-size:17px;line-height:2.1}
.chinese-passage p{margin:18px 0}
.paragraph-number{display:inline-block;font-size:11px;line-height:20px;width:20px;border:1px solid var(--border);border-radius:50%;text-align:center;vertical-align:2px;margin-right:8px;color:var(--textMuted)}
.textual-board{padding:18px 20px;background:var(--background);border-top:2px solid var(--primary)}
.reasoning-stops{display:flex;margin:20px 0 30px;gap:10px}
.reasoning-stops span{flex:1;border-bottom:2px solid var(--border);padding:0 0 10px;font-size:12px;color:var(--textMuted)}
.reasoning-stops .is-current{border-color:var(--primary);color:var(--primary);font-weight:600}
.textual-board blockquote{font-size:21px;line-height:1.95;margin:20px 0 24px}
.textual-board mark{background:var(--highlight);color:var(--textPrimary);box-decoration-break:clone}
.textual-board [data-textual-focus]>p{font-size:14px;line-height:1.9;color:var(--textSecondary);margin:0}
.history-era{display:flex;align-items:center;gap:20px;border-bottom:1px solid var(--border);padding-bottom:14px;margin-bottom:8px}
.history-era>span{font-family:var(--serif);font-size:28px}
.history-era>div{flex:1;font-size:12px;color:var(--textMuted);text-align:center}
.history-card{display:grid;grid-template-columns:26px 1fr auto;gap:12px;align-items:start;padding:14px 10px;border-bottom:1px solid var(--border);transition:background 200ms}
.history-card>span{font-size:15px;color:var(--textMuted)}
.history-card strong{font-size:14px;font-weight:600}
.history-card p{font-size:12px;line-height:1.8;color:var(--textSecondary);margin:5px 0 0}
.history-card small{font-size:10px;padding:3px 6px;color:var(--textMuted);border:1px solid var(--border);white-space:nowrap}
.history-card.is-current{background:var(--accentSoft)}
.history-card.is-current>span,.history-card.is-current small{color:var(--primary)}
.history-card.is-current small{border-color:var(--primary)}
.history-conclusion{padding:16px 0 0;line-height:1.8}
.history-conclusion>span{font-size:11px;color:var(--accentInk)}
.history-conclusion p{font-size:14px;margin:6px 0}
.history-conclusion strong{font-size:13px;font-weight:500}
.history-conclusion small{font-size:12px;color:var(--textSecondary)}
.history-source{padding:16px 0;border-bottom:1px solid var(--border)}
.history-source>span{font-size:12px;color:var(--accentInk)}
.history-source h4{margin:8px 0;font-size:17px}
.history-source p{margin:0;line-height:1.9}
.science-visual{display:block;width:100%;height:255px;margin:12px auto 8px;overflow:visible}
.science-visual text{font-family:inherit;font-size:12px;fill:var(--textSecondary)}
.science-visual .vessel{fill:none;stroke:var(--textPrimary);stroke-width:2}
.science-visual .liquid{fill:var(--accentSoft)}
.science-visual .stone{fill:var(--accent);stroke:var(--accentInk);stroke-width:1}
.science-visual .scale-box{fill:var(--inset);stroke:var(--border)}
.science-visual [data-chem-scale]{font-size:19px;fill:var(--primary)}
.chart-axis{fill:none;stroke:var(--textMuted);stroke-width:1}
.chart-grid,.height-guide{fill:none;stroke:var(--border);stroke-width:1;stroke-dasharray:3 4}
.mass-curve{fill:none;stroke:var(--primary);stroke-width:2.5;stroke-dasharray:1;stroke-dashoffset:1}
.mass-point{fill:var(--primary);stroke:var(--surface);stroke-width:2}
.gas-bubbles circle{fill:var(--surface);stroke:var(--primary);stroke-width:1.3;animation:bubble-rise 1500ms ease-in infinite;animation-play-state:paused}
.gas-bubbles circle:nth-child(2){animation-delay:-500ms}
.gas-bubbles circle:nth-child(3){animation-delay:-1000ms}
#main-demo[data-playing="true"][data-gas-active="true"] .gas-bubbles circle{animation-play-state:running}
#main-demo[data-gas-active="false"] .gas-bubbles{visibility:hidden}
@keyframes bubble-rise{from{transform:translateY(18px);opacity:0}35%{opacity:1}to{transform:translateY(-16px);opacity:0}}
.science-status{display:flex;justify-content:space-between;gap:12px;align-items:baseline;border-top:1px solid var(--border);padding:13px 0;font-size:13px}
.science-status>span{color:var(--textSecondary);font-size:12px}
.science-status strong{font-weight:500;color:var(--primary)}
.mass-equivalence{display:flex;align-items:center;justify-content:space-between;flex-wrap:wrap;gap:8px 20px;padding:16px 18px;background:var(--background);min-height:96px}
.mass-equivalence>span{flex-basis:100%;font-size:12px;color:var(--textMuted)}
.mass-equivalence>strong{font-size:15px;font-weight:500;line-height:1.8}
.mass-equivalence>div{display:flex;flex-direction:column;gap:3px;text-align:center;min-width:80px}
.mass-equivalence>div>span{font-size:13px;color:var(--textSecondary)}
.mass-equivalence>div>strong{font-size:25px;font-weight:500}
.mass-equivalence>p{width:100%;font-size:13px;margin:5px 0 0;text-align:center}
.science-visual .sea{fill:var(--accentSoft)}
.science-visual .mountain{fill:var(--inset);stroke:var(--border);stroke-width:1.5}
.wind-rise,.wind-fall{fill:none;stroke:var(--primary);stroke-width:2.5;stroke-linecap:round;stroke-dasharray:1}
.wind-fall{stroke:var(--accentInk)}
.wind-arrow{fill:none;stroke:var(--primary);stroke-width:2.5;stroke-linecap:round;stroke-linejoin:round}
.fall-arrow{stroke:var(--accentInk)}
.rain-cloud{fill:var(--accentSoft);stroke:var(--primary);stroke-width:1.2}
.rain-strokes{fill:none;stroke:var(--primary);stroke-width:1.5}
.geo-point{fill:var(--surface);stroke:var(--textMuted);stroke-width:1.5}
.geo-point.is-current{fill:var(--primary);stroke:var(--surface);stroke-width:2}
.geo-chain{display:flex;align-items:center;justify-content:center;gap:12px;background:var(--background);font-size:13px;padding:14px 10px;margin:15px 0 0}
.geo-chain b{font-weight:400;color:var(--accentInk)}
#full-material-content .science-visual,.material-page .science-visual{max-width:550px;height:300px}
#full-material-content .wind-rise,#full-material-content .wind-fall,.material-page .wind-rise,.material-page .wind-fall{stroke-dashoffset:0}
.material-page .source-question h4{font-size:18px}
.material-page .reference-analysis{padding:16px 22px;background:var(--background);margin:24px 0}
.material-page .reference-analysis h3{font-size:18px;margin-top:0}
.material-page .reference-analysis li{margin:14px 0;line-height:1.9}
@media(max-width:700px){
  .window-toolbar{display:grid;grid-template-columns:1fr auto;gap:10px;padding:11px}
  .window-brand{grid-row:1;grid-column:1}
  .window-toolbar>.toolbar-tag{grid-row:1;grid-column:2;display:inline;font-size:10px}
  .subject-tabs{grid-row:2;grid-column:1 / -1;width:100%;gap:1px;padding:3px}
  .subject-tabs button{min-width:0;min-height:44px;padding:7px 2px;font-size:12px}
  .subject-brief{font-size:11px;line-height:1.8;margin:0 0 8px}
  .source-label{font-size:10px;margin-bottom:7px}
  .source-title{font-size:23px}
  .chinese-passage{font-size:16px;line-height:2}
  .source-question{margin-top:20px}
  .source-question p{font-size:15px}
  .source-links{font-size:11px}
  .textual-board{padding:10px 12px}
  .reasoning-stops{gap:8px;margin:9px 0 12px}
  .reasoning-stops span{font-size:10px;padding-bottom:7px}
  .textual-board blockquote{font-size:15px;line-height:1.9;margin:10px 0 12px}
  .textual-board [data-textual-focus]>p{font-size:11px;line-height:1.85}
  #main-demo[data-scene="chinese"] .material-pane{height:340px}
  #main-demo[data-scene="history"] .material-pane{height:450px}
  #main-demo[data-scene="chemistry"] .material-pane{height:395px}
  #main-demo[data-scene="geography"] .material-pane{height:365px}
  .history-era{gap:10px;padding-bottom:7px;margin-bottom:3px}
  .history-era>span{font-size:21px}
  .history-era>div{font-size:10px}
  .history-card{grid-template-columns:17px 1fr auto;gap:7px;padding:9px 5px}
  .history-card>span{font-size:12px}
  .history-card strong{font-size:12px}
  .history-card p{font-size:12px;line-height:1.7;margin-top:3px}
  .history-card small{font-size:9px;padding:2px 4px}
  .history-conclusion{padding-top:8px}
  .history-conclusion>span{font-size:10px}
  .history-conclusion p,.history-conclusion strong{font-size:11px;margin:4px 0}
  .history-conclusion small{font-size:10px}
  .science-visual{height:174px;margin:3px auto}
  .science-visual text{font-size:15px}
  .science-status{font-size:11px;padding:9px 0;gap:6px}
  .science-status>span{font-size:10px}
  .mass-equivalence{padding:8px 10px;min-height:59px;gap:3px 10px}
  .mass-equivalence>span,.mass-equivalence>div>span,.mass-equivalence>p{font-size:10px}
  .mass-equivalence>strong{font-size:11px}
  .mass-equivalence>div{min-width:65px}
  .mass-equivalence>div>strong{font-size:18px}
  .geo-chain{font-size:10px;gap:8px;padding:9px 6px;margin:3px 0 0}
  #full-material-content .science-visual,.material-page .science-visual{height:auto}
  #full-material-content .data-table{font-size:11px;table-layout:fixed;width:100%}
  #full-material-content .data-table th{font-size:10px}
  #full-material-content .data-table caption{font-size:11px;text-align:left;margin-bottom:8px}
  .material-page .reference-analysis{padding:14px}
}
@media(prefers-reduced-motion:reduce){
  .gas-bubbles circle{animation:none}
  .history-card{transition:none}
}