:root{--bg:#f6f3ea;--card:#fff;--ink:#1f2a37;--muted:#6b7684;--accent:#ff9f1c;--accent-2:#2a9d8f;--ok:#2e9e5b;--ng:#e2574c;--line:#e5e0d3;--sel:#ffe7c2}
*{box-sizing:border-box;-webkit-tap-highlight-color:transparent}
html,body{margin:0;min-height:100%;background:var(--bg);color:var(--ink);font-family:"PingFang TC","Microsoft JhengHei","Noto Sans TC",system-ui,sans-serif}
.hidden{display:none!important}
.bar{position:sticky;top:0;display:flex;align-items:center;gap:12px;padding:12px 18px;background:#2b3a2f;color:#fff;font-size:17px;z-index:2}
.seg-info{flex:1;text-align:right;opacity:.8;font-size:15px}
.link{background:none;border:1px solid #ffffff55;color:#fff;border-radius:8px;padding:4px 10px;font:inherit;font-size:14px}
main{max-width:860px;margin:0 auto;padding:22px 18px 60px}
.view{background:var(--card);border-radius:22px;padding:26px;box-shadow:0 6px 24px #0000000f}
h1,h2{font-family:"LXGW WenKai TC",serif;margin:.2em 0 .6em}
h1{font-size:34px}h2{font-size:30px;text-align:center}
label{display:flex;flex-direction:column;gap:6px;font-size:18px;margin-bottom:16px}
input,select{font:inherit;font-size:22px;padding:12px 14px;border:2px solid var(--line);border-radius:14px;background:#fff}
.big-btn{width:100%;font:inherit;font-size:24px;font-weight:700;padding:16px;border:0;border-radius:16px;background:var(--accent);color:#2a1a00}
.big-btn:disabled{opacity:.45}
.big-btn.alt{background:var(--accent-2);color:#fff}
.msg{color:var(--ng);min-height:1.2em;font-size:17px;text-align:center}
.look{font-size:80px;text-align:center}
.sub{text-align:center;color:var(--muted);font-size:20px}
.q-tag{display:inline-block;background:var(--sel);border-radius:10px;padding:4px 12px;font-weight:700;margin-bottom:10px}
.q-prompt{font-family:"LXGW WenKai TC",serif;font-size:30px;line-height:1.6;margin-bottom:20px}
.frac{display:inline-flex;flex-direction:column;align-items:center;vertical-align:middle;margin:0 .15em;line-height:1.05;font-size:.92em}
.frac .num{border-bottom:2px solid currentColor;padding:0 .2em}.frac .den{padding:0 .2em}
mark{background:none;border-bottom:3px solid var(--accent)}
.opts{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:14px;margin-bottom:18px}
.opt{display:flex;align-items:center;gap:14px;font:inherit;font-size:24px;text-align:left;padding:18px;border:3px solid var(--line);border-radius:18px;background:#fff;color:var(--ink)}
.opt b{display:grid;place-items:center;width:44px;height:44px;border-radius:50%;background:var(--line);flex:none}
.opt.sel{border-color:var(--accent);background:var(--sel)}
.opt.sel b{background:var(--accent);color:#fff}
.fill-show{font-size:44px;text-align:center;border:3px solid var(--line);border-radius:18px;padding:14px;min-height:84px;margin-bottom:14px;font-variant-numeric:tabular-nums;letter-spacing:.06em}
.keypad{display:grid;grid-template-columns:repeat(4,1fr);gap:10px;margin-bottom:16px}
.keypad button{font:inherit;font-size:30px;padding:16px 0;border:0;border-radius:14px;background:#efe9da;color:var(--ink)}
.keypad button.fn{background:#e1d8c3}
.pad-wrap{position:relative;border:3px solid var(--line);border-radius:18px;overflow:hidden;margin-bottom:12px;background:#fff}
.pad-wrap canvas{display:block;width:100%;height:46vh;min-height:300px}
.pad-wrap img{display:block;width:100%;max-height:52vh;object-fit:contain;background:#f3f3f3}
.tools{display:flex;gap:10px;flex-wrap:wrap;margin-bottom:16px}
.tools button,.tools label{flex:1;margin:0;display:flex;align-items:center;justify-content:center;font:inherit;font-size:19px;padding:12px;border:0;border-radius:14px;background:#efe9da;color:var(--ink);text-align:center}
.tools input[type=file]{display:none}
.rec{display:flex;flex-direction:column;align-items:center;gap:14px;margin:10px 0 20px}
.rec-btn{width:150px;height:150px;border-radius:50%;border:0;background:var(--ng);color:#fff;font:inherit;font-size:24px;font-weight:700;box-shadow:0 8px 20px #e2574c55}
.rec-btn.on{animation:pulse 1.2s infinite}
@keyframes pulse{0%,100%{box-shadow:0 0 0 0 #e2574c88}50%{box-shadow:0 0 0 22px #e2574c00}}
.rec-time{font-size:28px;font-variant-numeric:tabular-nums;color:var(--muted)}
audio{width:100%}
.done-body{font-size:21px;line-height:1.7;text-align:center}
.result-box{border-radius:16px;padding:14px 18px;margin:12px 0;text-align:left;background:#f4f7f5}
.result-box.ok{background:#e5f5ec;border-left:6px solid var(--ok)}
.result-box.ng{background:#fdecea;border-left:6px solid var(--ng)}
.spinner{width:40px;height:40px;border:5px solid var(--line);border-top-color:var(--accent);border-radius:50%;animation:spin 1s linear infinite;margin:10px auto}
@keyframes spin{to{transform:rotate(360deg)}}