:root{
  --bg:#fbfbfc; --panel:#ffffff; --ink:#16202e; --muted:#5d6b7c; --line:#e3e8ef;
  --red:#a3172a; --red-soft:#fdeef0; --blue:#12395f; --blue-soft:#eaf1f8;
  --gold:#a4761a; --gold-soft:#fbf3e2; --green:#1a6b4f; --green-soft:#e9f6f0;
  --radius:14px; --shadow:0 1px 2px rgba(16,24,40,.05),0 8px 24px rgba(16,24,40,.06);
  --font:"Noto Sans TC","PingFang TC","Microsoft JhengHei",system-ui,-apple-system,"Segoe UI",sans-serif;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--ink);font-family:var(--font);line-height:1.75;font-size:16.5px;-webkit-font-smoothing:antialiased}
a{color:var(--blue);text-decoration:none}
a:hover{color:var(--red)}
.wrap{max-width:1080px;margin:0 auto;padding:0 18px 64px}
header.top{position:sticky;top:0;z-index:40;background:rgba(251,251,252,.92);backdrop-filter:blur(10px);border-bottom:1px solid var(--line)}
.top-in{max-width:1080px;margin:0 auto;padding:10px 18px;display:flex;gap:14px;align-items:center;flex-wrap:wrap}
.brand{font-weight:800;font-size:1.02rem;letter-spacing:.02em;display:flex;align-items:center;gap:8px;color:var(--ink)}
.brand .dot{width:11px;height:11px;border-radius:50%;background:radial-gradient(circle at 30% 30%,#e0556b,#8b0f22)}
nav.main{display:flex;gap:4px;flex-wrap:wrap;margin-left:auto}
nav.main a{padding:6px 11px;border-radius:999px;font-size:.92rem;color:var(--muted);font-weight:600}
nav.main a:hover{background:var(--blue-soft);color:var(--blue)}
nav.main a.on{background:var(--ink);color:#fff}
.hero{padding:44px 0 22px}
.hero h1{font-size:2.05rem;line-height:1.28;margin:0 0 12px;letter-spacing:-.01em}
.hero p{color:var(--muted);max-width:760px;margin:0 0 8px}
.tagline{display:inline-flex;gap:8px;align-items:center;background:var(--red-soft);color:var(--red);font-size:.82rem;font-weight:700;padding:4px 12px;border-radius:999px;margin-bottom:14px}
.stats{display:flex;gap:10px;flex-wrap:wrap;margin:20px 0 6px}
.stat{background:var(--panel);border:1px solid var(--line);border-radius:var(--radius);padding:12px 16px;min-width:118px;box-shadow:var(--shadow)}
.stat b{display:block;font-size:1.45rem;line-height:1.2;letter-spacing:-.02em}
.stat span{font-size:.78rem;color:var(--muted)}
.grid{display:grid;gap:16px}
.g3{grid-template-columns:repeat(3,1fr)}
.g2{grid-template-columns:repeat(2,1fr)}
@media(max-width:820px){.g3,.g2{grid-template-columns:1fr}}
.card{background:var(--panel);border:1px solid var(--line);border-radius:var(--radius);padding:20px;box-shadow:var(--shadow)}
.card h3{margin:.1rem 0 .4rem;font-size:1.1rem}
.card p{color:var(--muted);margin:.2rem 0 .8rem;font-size:.94rem}
.zone-link{display:inline-flex;align-items:center;gap:6px;font-weight:700;color:var(--red)}
.bar{height:6px;border-radius:99px;background:#eef1f6;overflow:hidden;margin:8px 0 4px}
.bar i{display:block;height:100%;background:linear-gradient(90deg,#a3172a,#d4435c)}
.bar.blue i{background:linear-gradient(90deg,#12395f,#3a73a8)}
.bar.green i{background:linear-gradient(90deg,#1a6b4f,#3aa07c)}
.muted{color:var(--muted)}
.small{font-size:.86rem}
h2.sec{font-size:1.3rem;margin:34px 0 14px;padding-left:12px;border-left:4px solid var(--red);line-height:1.3}
h3.sub{font-size:1.05rem;margin:22px 0 8px}
.chips{display:flex;gap:7px;flex-wrap:wrap}
.chip{font-size:.76rem;padding:2px 9px;border-radius:999px;background:var(--blue-soft);color:var(--blue);font-weight:600;border:1px solid #d6e3f0;cursor:pointer}
.chip.on{background:var(--blue);color:#fff}
.chip.hit{background:var(--red-soft);color:var(--red);border-color:#f3d3d8}
.badge{display:inline-block;font-size:.72rem;font-weight:700;padding:2px 8px;border-radius:6px;background:var(--green-soft);color:var(--green)}
.badge.todo{background:#f1f3f7;color:#7b8794}
.badge.hot{background:var(--red-soft);color:var(--red)}
table.list{width:100%;border-collapse:collapse;font-size:.93rem}
table.list th,table.list td{text-align:left;padding:9px 8px;border-bottom:1px solid var(--line);vertical-align:top}
table.list th{font-size:.8rem;color:var(--muted);font-weight:700;letter-spacing:.02em}
table.list tr:hover td{background:#fcfdff}
.q{background:var(--panel);border:1px solid var(--line);border-radius:var(--radius);padding:18px 20px;margin:14px 0;box-shadow:var(--shadow)}
.q .qhead{display:flex;gap:10px;align-items:baseline;flex-wrap:wrap;margin-bottom:6px}
.q .no{font-weight:800;color:var(--red);font-size:.95rem}
.q .stem{font-weight:600;margin:.2rem 0 .7rem}
.q ol.opts{list-style:none;margin:0;padding:0;display:grid;gap:6px}
.q ol.opts li{border:1px solid var(--line);border-radius:10px;padding:8px 12px;font-size:.95rem;cursor:pointer;transition:.12s;background:#fff}
.q ol.opts li:hover{border-color:#c9d6e6}
.q ol.opts li .k{font-weight:700;color:var(--blue);margin-right:8px}
.q ol.opts li.ok{background:var(--green-soft);border-color:#9fd4bd}
.q ol.opts li.bad{background:var(--red-soft);border-color:#f0c3cb}
.answer{display:none;margin-top:12px;border-top:1px dashed var(--line);padding-top:12px}
.q.open .answer{display:block}
.ansline{font-weight:800;color:var(--green)}
.explain{margin:.5rem 0 0}
.why{margin:.4rem 0 0;padding-left:0;list-style:none;font-size:.9rem;color:var(--muted)}
.why li{margin:.15rem 0}
.keypoint{margin-top:.6rem;background:var(--gold-soft);border-left:3px solid var(--gold);padding:7px 12px;border-radius:8px;font-size:.9rem}
.toolbar{display:flex;gap:10px;align-items:center;flex-wrap:wrap;position:sticky;top:53px;background:rgba(251,251,252,.95);backdrop-filter:blur(8px);padding:10px 0;z-index:30;border-bottom:1px solid var(--line)}
.toolbar button{font:inherit;font-size:.88rem;font-weight:700;padding:6px 13px;border-radius:999px;border:1px solid var(--line);background:#fff;cursor:pointer;color:var(--ink)}
.toolbar button:hover{border-color:#c9d6e6}
.toolbar button.primary{background:var(--red);color:#fff;border-color:var(--red)}
.searchbox{flex:1;min-width:180px}
.searchbox input{width:100%;font:inherit;padding:8px 14px;border-radius:999px;border:1px solid var(--line);background:#fff}
.section-block{border-left:3px solid #e6ebf2;padding:2px 0 2px 15px;margin:16px 0}
.section-block h4{margin:.2rem 0 .5rem;font-size:1rem}
.section-block ul{margin:0;padding-left:1.1rem}
.section-block li{margin:.3rem 0}
.pagehead{border-bottom:1px solid var(--line);padding-bottom:14px;margin-bottom:8px}
.crumbs{font-size:.84rem;color:var(--muted);margin:16px 0 6px}
.crumbs a{color:var(--muted)}
.pagehead h1{font-size:1.7rem;margin:.2rem 0 .3rem;line-height:1.3}
.pager{display:flex;justify-content:space-between;gap:10px;margin:26px 0;font-weight:700;font-size:.92rem}
details.src{margin-top:18px;background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:12px 16px}
details.src summary{cursor:pointer;font-weight:700;color:var(--muted);font-size:.9rem}
details.src pre{white-space:pre-wrap;font-size:.82rem;line-height:1.6;color:#465264;max-height:460px;overflow:auto;margin:10px 0 0}
.gloss{display:grid;gap:12px;grid-template-columns:repeat(2,1fr)}
@media(max-width:820px){.gloss{grid-template-columns:1fr}}
.gterm{background:#fff;border:1px solid var(--line);border-radius:12px;padding:14px 16px}
.gterm b{font-size:1rem}
.gterm .en{color:var(--muted);font-size:.85rem;margin-left:6px}
.gterm p{margin:.35rem 0 0;font-size:.92rem}
.note{background:var(--gold-soft);border:1px solid #f0e0bd;border-radius:12px;padding:12px 16px;font-size:.9rem;color:#6b5416}
footer{border-top:1px solid var(--line);margin-top:40px;padding:22px 0 40px;color:var(--muted);font-size:.84rem}
.hits li{margin:.25rem 0}
.hits a{font-weight:600}
.pill{display:inline-block;background:var(--blue-soft);color:var(--blue);font-size:.74rem;padding:1px 8px;border-radius:999px;font-weight:700}
/* 教科書（tm）區 */
.bookmeta{display:flex;gap:10px;flex-wrap:wrap;align-items:center;font-size:.86rem;color:var(--muted);margin:.2rem 0 .8rem}
.quicktools{display:flex;gap:8px;flex-wrap:wrap;margin:16px 0}
.quicktools a{background:#fff;border:1px solid var(--line);border-radius:999px;padding:6px 14px;font-size:.88rem;font-weight:700}
.quicktools a:hover{border-color:#c9d6e6}
.tsec{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:20px 22px;margin:16px 0;box-shadow:var(--shadow)}
.tsec h3{margin:.1rem 0 .2rem;font-size:1.06rem}
.tsec .sid{color:var(--red);font-weight:800;margin-right:6px}
.tsec .sen{font-size:.84rem;color:var(--muted);margin-bottom:.4rem}
.tsec .bpara{margin:.55rem 0}
.tsec .bsubhead{font-weight:800;margin:1rem 0 .3rem;color:var(--blue);font-size:1rem;border-left:3px solid var(--blue);padding-left:9px}
.tsec ul.blist{margin:.5rem 0;padding-left:1.2rem}
.tsec ul.blist li{margin:.25rem 0}
table.tbl{width:100%;border-collapse:collapse;font-size:.9rem;margin:.7rem 0;display:block;overflow-x:auto}
table.tbl caption{caption-side:top;text-align:left;font-weight:700;font-size:.85rem;color:var(--muted);padding-bottom:5px}
table.tbl th,table.tbl td{border:1px solid var(--line);padding:7px 10px;text-align:left;vertical-align:top;min-width:90px}
table.tbl th{background:var(--blue-soft);color:var(--blue);font-weight:700;white-space:nowrap}
table.tbl tbody tr:nth-child(even){background:#fafbfd}
.bcallout{background:var(--gold-soft);border-left:4px solid var(--gold);border-radius:10px;padding:11px 15px;margin:.7rem 0;font-size:.94rem}
.bcallout b{display:block;color:#6b5416;margin-bottom:2px}
.bformula{background:#f4f7fb;border:1px dashed #c9d6e6;border-radius:10px;padding:10px 14px;margin:.7rem 0;font-family:ui-monospace,Menlo,monospace;font-size:.9rem}
.bformula .fn{display:block;font-family:var(--font);color:var(--muted);font-size:.82rem;margin-top:4px}
.kpbox ul{margin:.3rem 0 0;padding-left:1.15rem}
.kpbox li{margin:.35rem 0}
.kpbox li::marker{color:var(--red)}
.flashgrid{display:grid;gap:10px;grid-template-columns:repeat(3,1fr)}
@media(max-width:820px){.flashgrid{grid-template-columns:1fr}}
.fcard{background:#fff;border:1px solid var(--line);border-radius:12px;padding:13px 15px;cursor:pointer;min-height:92px;transition:.15s}
.fcard:hover{border-color:#c9d6e6;box-shadow:var(--shadow)}
.fcard .fq{font-weight:700;font-size:.94rem}
.fcard .fa{display:none;margin-top:8px;padding-top:8px;border-top:1px dashed var(--line);font-size:.9rem;color:#3c4a5c}
.fcard.open{border-color:var(--green);background:var(--green-soft)}
.fcard.open .fa{display:block}
.fcard .tag{font-size:.7rem;color:var(--muted)}