:root{color-scheme:light;--paper:#f7f5f0;--ink:#171714;--muted:#67665e;--line:#d8d4ca;--green:#1e4d3a}*{box-sizing:border-box}body{margin:0;background:var(--paper);color:var(--ink);font-family:Inter,-apple-system,BlinkMacSystemFont,'Segoe UI','PingFang SC','Microsoft YaHei',sans-serif;display:flex;flex-direction:column;height:100vh;height:100dvh;-webkit-font-smoothing:antialiased}button,select{font:inherit;color:inherit}button,a,select{-webkit-tap-highlight-color:transparent}button{cursor:pointer;min-height:44px;border:1px solid var(--line);background:transparent;padding:8px 16px;border-radius:6px}button:hover{background:#ebe8df}button:focus-visible,a:focus-visible,select:focus-visible{outline:3px solid #498569;outline-offset:3px}button:disabled{opacity:.35;cursor:default}header{display:flex;align-items:center;justify-content:space-between;gap:12px;padding:8px max(24px,env(safe-area-inset-right)) 8px max(24px,env(safe-area-inset-left));border-bottom:1px solid var(--line);flex-shrink:0}.brand{font-size:13px;font-weight:750;letter-spacing:.06em;color:inherit;text-decoration:none}.brand span{font-family:Georgia,serif;font-style:italic;font-weight:400;letter-spacing:0;margin-left:8px;color:var(--muted);font-size:16px}.languages{display:flex;border:1px solid var(--line);border-radius:7px;padding:3px}.languages button{border:0;min-height:36px;padding:6px 18px}.languages button[aria-pressed=true]{background:var(--green);color:#fff}main{max-width:1440px;width:100%;margin:auto;flex:1;min-height:0;display:flex;flex-direction:column;padding:24px max(32px,env(safe-area-inset-right)) 0 max(32px,env(safe-area-inset-left));touch-action:pan-y pinch-zoom}.topicbar{display:flex;justify-content:space-between;align-items:center;gap:12px;padding-bottom:20px;flex-shrink:0}.eyebrow{font-size:11px;font-weight:700;letter-spacing:.14em;color:var(--green)}h1{font-size:26px;font-weight:500;margin:6px 0 0;letter-spacing:-.02em}.jump{font-size:14px;color:var(--muted);white-space:nowrap}select{max-width:240px;padding:10px;border:1px solid var(--line);border-radius:5px;background:var(--paper);font-size:14px}.sheet{display:grid;grid-template-columns:minmax(0,2.3fr) minmax(220px,1fr);min-height:0;flex:1;border-top:1px solid var(--line)}.qa,aside{overflow:auto;overscroll-behavior-y:contain;scrollbar-width:thin;padding:20px 28px 30px 0}.qa{padding-right:32px}aside{border-left:1px solid var(--line);padding-left:28px;padding-right:0}h2{font-size:12px;letter-spacing:.09em;color:var(--green);font-weight:600;margin:0 0 16px}h2 span{color:var(--muted);margin-left:8px}.question{font-family:Georgia,'PingFang SC','Microsoft YaHei',serif;font-size:clamp(20px,2.1vw,28px);line-height:1.4;margin-bottom:24px}.answer-heading{display:flex;align-items:center;justify-content:space-between;gap:10px;border-top:1px solid var(--line);padding-top:10px;margin-bottom:10px}.answer-heading h2{margin:0}#answer-toggle{font-size:12px;border:0;padding:6px;min-height:32px;color:var(--muted)}#answer{font-size:clamp(17px,1.5vw,21px);line-height:1.65}#answer p{margin:0 0 1em}.pinyin{display:block;font-family:inherit;font-size:12px;line-height:1.55;color:var(--muted);font-weight:400;margin-top:5px;letter-spacing:0}#answer .pinyin{font-size:13px}dl{margin:0}dt{font-size:17px;line-height:1.4;font-weight:600}dd{font-size:14px;color:var(--muted);margin:7px 0 20px;padding-bottom:20px;border-bottom:1px solid var(--line)}dd:last-child{border:0;margin:0}footer{display:flex;align-items:center;justify-content:space-between;border-top:1px solid var(--line);padding:8px max(24px,env(safe-area-inset-right)) max(8px,env(safe-area-inset-bottom)) max(24px,env(safe-area-inset-left));flex-shrink:0}.position{text-align:center;display:flex;align-items:center;gap:18px}.position strong{font-size:15px;font-variant-numeric:tabular-nums;color:var(--green)}.position span{font-size:12px;color:var(--muted)}#next{background:var(--green);color:white;border-color:var(--green)}dialog{background:var(--paper);color:var(--ink);border:1px solid var(--line);border-radius:12px;width:min(480px,calc(100% - 32px));padding:24px}dialog::backdrop{background:#17171480}.dialog-head{display:flex;justify-content:space-between;align-items:center}.dialog-head h2{font-size:20px;letter-spacing:0;margin:0}dialog p{font-size:14px;line-height:1.6;color:var(--muted)}.download{display:flex;justify-content:space-between;gap:10px;color:var(--green);text-decoration:none;padding:20px 0;border-top:1px solid var(--line);font-size:15px}
@media(orientation:landscape) and (max-height:550px){header{padding-top:4px;padding-bottom:4px}main{padding-top:10px}.topicbar{padding-bottom:10px}.eyebrow{display:none}h1{font-size:20px;margin:0}.sheet{grid-template-columns:minmax(0,2.35fr) minmax(205px,1fr)}.qa,aside{padding-top:14px}.question{font-size:20px;margin-bottom:16px}#answer{font-size:17px;line-height:1.6}h2{font-size:11px;margin-bottom:10px}footer{padding-top:4px;padding-bottom:max(4px,env(safe-area-inset-bottom))}.jump{font-size:0}select{max-width:230px;padding:8px}dt{font-size:16px}dd{margin-bottom:12px;padding-bottom:12px}}
@media(max-width:600px) and (orientation:portrait){header{padding-left:16px;padding-right:16px;gap:6px}.brand span{display:none}.languages button{padding-left:13px;padding-right:13px}#downloads{font-size:13px;padding:8px 10px}main{padding:20px 20px 0}.topicbar{align-items:flex-start}.eyebrow{font-size:9px}h1{font-size:22px}.jump{font-size:0}select{max-width:132px}.sheet{display:block;overflow:auto;overscroll-behavior-y:contain}.qa,aside{overflow:visible;padding:20px 0}.qa{padding-bottom:4px}aside{border-left:0;border-top:1px solid var(--line)}.position{display:block}.position span{display:block;font-size:10px;margin-top:4px}.question{font-size:23px}footer{padding-left:16px;padding-right:16px}#answer{font-size:18px}}
.player{display:flex;align-items:center;gap:10px;min-width:0}.speech-toggle{background:#fff;border-color:var(--green);color:var(--green);font-size:13px;white-space:nowrap}.speech-toggle[aria-pressed=true]{background:var(--green);color:#fff}.play-icon{display:inline-block;width:1em}.repeat-one{display:flex;align-items:center;gap:6px;font-size:12px;color:var(--muted);white-space:nowrap}.repeat-one input{accent-color:var(--green);width:16px;height:16px}.speech-status{font-size:11px;color:var(--muted);white-space:nowrap}
@media(max-width:720px){footer{display:grid;grid-template-columns:auto 1fr auto;gap:6px 10px}.player{grid-column:1/-1;grid-row:1;justify-content:center}.position{grid-column:2;grid-row:2;justify-self:center}#prev{grid-column:1;grid-row:2}#next{grid-column:3;grid-row:2}}
@media(orientation:landscape) and (max-height:550px){footer{gap:8px}.position span{display:none}.player{gap:6px}.speech-toggle{padding:6px 10px;min-height:38px}}