:root{--paper:#f7f8f5;--ink:#203832;--muted:#65736c;--line:#e3e8e1;--green:#23644f;--mint:#e9f1e8;--amber:#916521;--blue:#4c658c;--radius:18px}*{box-sizing:border-box}body{margin:0;background:var(--paper);color:var(--ink);font-family:"Microsoft YaHei UI","Microsoft YaHei",system-ui,sans-serif;font-size:14px;line-height:1.65}button,input,select{font:inherit}button,a,input,select{-webkit-tap-highlight-color:transparent}button,a{touch-action:manipulation}button{cursor:pointer}a{color:inherit;text-decoration:none}button{color:inherit}button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible{outline:3px solid #bf8c38;outline-offset:4px}button{transition:background .18s,transform .18s}button:hover{filter:brightness(.98)}.sidebar{width:238px;height:100dvh;position:fixed;inset:0 auto 0 0;background:#fff;border-right:1px solid var(--line);padding:35px 24px 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/* Keep experiment names readable on narrow touch screens. */
.reciprocal-guide{margin-top:20px;background:white;border:1px solid var(--line);border-radius:14px;padding:23px}.reciprocal-actions{display:flex;align-items:center;gap:10px;flex-wrap:wrap;font-size:12px}.reciprocal-actions button{min-height:44px;padding:8px 14px;border:1px solid var(--line);border-radius:8px;background:var(--mint)}.reciprocal-actions label{display:flex;align-items:center;gap:8px;min-height:44px;margin-left:auto}.reciprocal-actions input{width:18px;height:18px;accent-color:var(--green)}.reciprocal-warning{margin-top:15px;padding:12px 15px;border-radius:8px;background:#faf0db;color:#735416;font-size:12px}.reciprocal-learning{display:grid;grid-template-columns:1fr 1fr;gap:25px;margin-top:24px}.reciprocal-learning h3{font-size:14px;margin-bottom:12px}.reciprocal-learning p,.reciprocal-learning li,.reciprocal-summary p{font-size:12px;line-height:1.9;color:var(--muted)}.reciprocal-learning ol{padding-left:20px;margin:0 0 10px}.table-scroll{overflow-x:auto}.reciprocal-table{border-collapse:collapse;width:100%;font-size:12px;margin-bottom:12px}.reciprocal-table th,.reciprocal-table td{text-align:center;padding:9px 6px;border:1px solid var(--line)}.reciprocal-table th{background:var(--mint)}.reciprocal-table caption{text-align:left;color:var(--muted);font-size:10px;margin-bottom:8px}.reciprocal-summary{margin-top:18px;border-top:1px solid var(--line);padding-top:12px}.reciprocal-summary summary{cursor:pointer;min-height:44px;line-height:44px;font-size:13px;color:var(--green)}.reciprocal-summary p{margin:8px 0}.facts strong{text-align:right}.segmented[aria-label="选择实验"]{flex-wrap:wrap}@media(max-width:850px){.reciprocal-learning{grid-template-columns:1fr}.reciprocal-guide{padding:18px}.reciprocal-actions label{margin-left:0}}
.curriculum-context{display:flex;align-items:center;gap:12px;flex-wrap:wrap;margin-bottom:18px;font-size:11px;color:var(--green)}.curriculum-context strong{background:#fff;padding:4px 10px;border-radius:6px;font-size:12px}.curriculum-context small{font-size:10px;color:#6b644e;margin-left:auto}.curriculum-context span{line-height:1.9}
@media(max-width:580px){.segmented[aria-label="选择实验"]{display:grid;grid-template-columns:repeat(3,minmax(0,1fr))}.segmented[aria-label="选择实验"] button{white-space:nowrap;padding:8px 5px}.intro-row{align-items:flex-start;flex-wrap:wrap}.intro-row>.small-link{padding:0;min-height:30px}.filters{flex-wrap:wrap;gap:8px}}
.board-panel:fullscreen{background:white;display:flex;flex-direction:column}.board-panel:fullscreen #board{flex:1;min-height:0;height:calc(100dvh - 125px);aspect-ratio:auto}.formula{font-size:clamp(17px,1.65vw,23px)}