:root{
  --navy:#182b49; --navy2:#2b4c7e; --amber:#f59e0b; --amber-soft:#fef3c7;
  --bg:#f4f7fa; --card:#ffffff; --line:#d9e1ea; --text:#1e293b; --muted:#5b6b7e;
  --ok:#0f766e; --ok-soft:#ccfbf1; --warn:#9a3412; --warn-soft:#ffedd5;
  --code-bg:#0f172a; --code-fg:#e2e8f0;
}
@media (prefers-color-scheme: dark){
  :root:not([data-theme="light"]){
    --navy:#dbe7ff; --navy2:#9db8e8; --amber:#fbbf24; --amber-soft:#3a2d0a;
    --bg:#0e1522; --card:#162033; --line:#2a3a54; --text:#e5ebf5; --muted:#9fb0c6;
    --ok:#5eead4; --ok-soft:#0b3b36; --warn:#fdba74; --warn-soft:#3b1d0a;
    --code-bg:#0a0f1a; --code-fg:#dbe4f2;
  }
}
:root[data-theme="dark"]{
  --navy:#dbe7ff; --navy2:#9db8e8; --amber:#fbbf24; --amber-soft:#3a2d0a;
  --bg:#0e1522; --card:#162033; --line:#2a3a54; --text:#e5ebf5; --muted:#9fb0c6;
  --ok:#5eead4; --ok-soft:#0b3b36; --warn:#fdba74; --warn-soft:#3b1d0a;
  --code-bg:#0a0f1a; --code-fg:#dbe4f2;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth;scroll-padding-top:76px}
body{margin:0;background:var(--bg);color:var(--text);
  font-family:"Noto Sans TC","Microsoft JhengHei","PingFang TC",system-ui,sans-serif;line-height:1.75;font-size:16px}
.wrap{max-width:980px;margin:0 auto;padding:0 16px}
a{color:var(--navy2)}
/* hero */
.hero{background:linear-gradient(135deg,#182b49,#2b4c7e);color:#fff;padding:44px 0 36px}
.hero .tag{display:inline-block;background:rgba(255,255,255,.12);border:1px solid rgba(255,255,255,.25);
  border-radius:99px;padding:3px 14px;font-size:13px;color:#fcd34d;margin-bottom:14px}
.hero h1{font-family:Bahnschrift,Arial,"Noto Sans TC",sans-serif;font-size:clamp(28px,6vw,46px);margin:0 0 6px;letter-spacing:.5px;line-height:1.2}
.hero p.sub{font-size:clamp(16px,3.2vw,20px);margin:0 0 18px;color:#e2e8f0}
.hero .lead{max-width:760px;color:#cbd5e1;margin:0}
.formula{display:grid;grid-template-columns:1fr;gap:10px;margin-top:24px}
@media(min-width:720px){.formula{grid-template-columns:1fr auto 1fr auto 1fr}}
.formula .box{background:rgba(255,255,255,.1);border:1px solid rgba(255,255,255,.2);border-radius:14px;padding:14px;text-align:center}
.formula .box b{display:block;color:#fcd34d}
.formula .op{align-self:center;text-align:center;font-size:26px;color:#fcd34d;font-weight:700}
/* nav */
nav.top{position:sticky;top:0;z-index:20;background:var(--card);border-bottom:1px solid var(--line)}
nav.top .wrap{display:flex;gap:6px;overflow-x:auto;padding:8px 16px;scrollbar-width:thin}
nav.top a{flex:0 0 auto;text-decoration:none;color:var(--text);border:1px solid var(--line);
  border-radius:10px;padding:5px 12px;font-size:14px;display:flex;flex-direction:column;align-items:center;line-height:1.3;min-width:78px}
nav.top a span.n{font-size:12px;color:var(--muted)}
nav.top a.done{background:var(--ok-soft);border-color:var(--ok)}
nav.top a.done span.n::after{content:" ✓"}
.progress{height:4px;background:var(--line)}
.progress i{display:block;height:100%;width:0;background:var(--amber);transition:width .3s}
/* sections */
section.st{background:var(--card);border:1px solid var(--line);border-radius:18px;padding:22px 18px;margin:22px 0}
@media(min-width:720px){section.st{padding:28px}}
.st .eyebrow{font-size:13px;font-weight:700;color:var(--navy2);letter-spacing:1px}
.st h2{margin:2px 0 6px;font-size:clamp(22px,4.5vw,28px);color:var(--navy)}
.st .goal{color:var(--muted);margin:0 0 16px}
.st h3{font-size:17px;margin:22px 0 8px;color:var(--navy)}
ol.steps{padding-left:22px;margin:8px 0}
ol.steps li{margin:6px 0}
.note{border-left:4px solid var(--amber);background:var(--amber-soft);padding:10px 14px;border-radius:0 10px 10px 0;margin:14px 0;font-size:15px}
.warn{border-left:4px solid var(--warn);background:var(--warn-soft);color:var(--text);padding:10px 14px;border-radius:0 10px 10px 0;margin:14px 0;font-size:15px}
.cards{display:grid;gap:12px;grid-template-columns:1fr}
@media(min-width:720px){.cards.c2{grid-template-columns:1fr 1fr}.cards.c3{grid-template-columns:repeat(3,1fr)}}
.card{border:1px solid var(--line);border-radius:12px;padding:12px 14px;background:var(--bg)}
.card b{color:var(--navy)}
/* prompt box */
.prompt{border:1px solid var(--line);border-radius:12px;overflow:hidden;margin:12px 0}
.prompt .bar{display:flex;justify-content:space-between;align-items:center;gap:8px;background:var(--navy2);color:#fff;padding:8px 12px;font-size:14px;font-weight:600}
.prompt .bar button{background:var(--amber);color:#1e293b;border:0;border-radius:8px;padding:6px 14px;font-weight:700;cursor:pointer;font-size:14px;min-height:36px}
.prompt pre{margin:0;padding:14px;background:var(--code-bg);color:var(--code-fg);white-space:pre-wrap;word-break:break-word;
  font-family:"Cascadia Mono",Consolas,"Noto Sans TC",monospace;font-size:13.5px;line-height:1.7;max-height:340px;overflow:auto}
.prompt .when{padding:8px 12px;font-size:14px;color:var(--muted);background:var(--bg);border-bottom:1px solid var(--line)}
/* settings */
.settings{background:var(--card);border:2px solid var(--amber);border-radius:16px;padding:16px;margin:22px 0}
.settings h2{margin:0 0 4px;font-size:19px;color:var(--navy)}
.settings p{margin:0 0 12px;color:var(--muted);font-size:14.5px}
.fields{display:grid;gap:10px;grid-template-columns:1fr}
@media(min-width:720px){.fields{grid-template-columns:1fr 1fr}}
.fields label{display:block;font-size:14px;font-weight:600;color:var(--navy)}
.fields input{width:100%;margin-top:4px;padding:9px 11px;border:1px solid var(--line);border-radius:9px;font:inherit;background:var(--bg);color:var(--text)}
/* checklist */
.check{background:var(--bg);border:1px solid var(--line);border-radius:12px;padding:12px 14px;margin-top:18px}
.check b{color:var(--navy)}
.check label{display:flex;gap:10px;align-items:flex-start;margin:8px 0;cursor:pointer}
.check input{margin-top:6px;width:18px;height:18px;flex:0 0 auto}
table{border-collapse:collapse;width:100%;font-size:14.5px;margin:10px 0}
th,td{border:1px solid var(--line);padding:8px 10px;text-align:left;vertical-align:top}
th{background:var(--navy2);color:#fff}
.tablewrap{overflow-x:auto}
.chat{display:flex;flex-direction:column;gap:10px;margin:12px 0}
.chat .m{max-width:92%;padding:10px 14px;border-radius:14px;font-size:15px;line-height:1.7;white-space:pre-line}
.chat .ai{align-self:flex-start;background:var(--bg);border:1px solid var(--line)}
.chat .me{align-self:flex-end;background:var(--amber-soft);border:1px solid var(--amber)}
.chat .who{display:block;font-size:12px;font-weight:700;color:var(--muted);margin-bottom:2px}
.chat .tip{align-self:center;max-width:96%;font-size:14px;color:var(--ok);background:var(--ok-soft);border-radius:10px;padding:6px 12px}
.timeline{border-left:3px solid var(--amber);margin:12px 0 12px 6px;padding-left:16px}
.timeline .tl{margin:0 0 16px}
.timeline .tl b{color:var(--navy)}
details.dt{border:1px solid var(--line);border-radius:10px;margin:10px 0;background:var(--bg)}
details.dt summary{cursor:pointer;padding:9px 14px;font-weight:600;color:var(--navy)}
details.dt .body{padding:4px 14px 12px;white-space:pre-line;font-size:15px}
footer{padding:28px 0 60px;color:var(--muted);font-size:14px}
.toast{position:fixed;left:50%;bottom:24px;transform:translateX(-50%);background:var(--navy);color:var(--bg);padding:10px 18px;border-radius:99px;font-size:14px;opacity:0;pointer-events:none;transition:opacity .2s;z-index:50}
.toast.show{opacity:1}
code{background:var(--bg);border:1px solid var(--line);border-radius:5px;padding:1px 6px;font-size:.92em}

nav.top .brand{flex:0 0 auto;text-decoration:none;font-weight:700;color:var(--navy);display:flex;align-items:center;padding:0 10px 0 0;font-family:Bahnschrift,Arial,sans-serif;white-space:nowrap}
nav.top a.cur{background:var(--navy2);color:#fff;border-color:var(--navy2)}
nav.top a.cur span.n{color:#e2e8f0}
.pgrid{display:grid;gap:14px;grid-template-columns:1fr}
@media(min-width:720px){.pgrid{grid-template-columns:1fr 1fr}}
a.pcard{display:block;text-decoration:none;color:var(--text);background:var(--card);border:1px solid var(--line);border-radius:16px;padding:18px;transition:transform .15s,border-color .15s}
a.pcard:hover{border-color:var(--amber);transform:translateY(-2px)}
a.pcard .no{font-family:Bahnschrift,Arial,sans-serif;font-weight:700;color:var(--amber);font-size:14px;letter-spacing:1px}
a.pcard h3{margin:2px 0 6px;color:var(--navy);font-size:20px}
a.pcard p{margin:0 0 8px;color:var(--muted);font-size:15px}
a.pcard .prog{font-size:13px;color:var(--ok)}
a.pcard .tag2{display:inline-block;font-size:12px;border-radius:99px;padding:1px 10px;background:var(--amber-soft);color:var(--warn);margin-left:6px}
.gate{border:2px dashed var(--amber);border-radius:16px;padding:14px 18px;margin:14px 0;background:var(--card);text-align:center}
.gate a{color:var(--navy);font-weight:700}
.pager{display:flex;justify-content:space-between;gap:10px;margin:22px 0}
.pager a{flex:1;text-decoration:none;border:1px solid var(--line);background:var(--card);border-radius:12px;padding:12px 14px;color:var(--navy)}
.pager a small{display:block;color:var(--muted);font-size:12px}
.pager a.next{text-align:right}
.draftbar{background:var(--warn-soft);border:1px solid var(--warn);border-radius:12px;padding:10px 14px;margin:14px 0;font-size:15px}
.settings details>summary{cursor:pointer;font-weight:700;color:var(--navy);font-size:16px}

.phead{background:linear-gradient(135deg,#182b49,#2b4c7e);color:#fff;border-radius:18px;padding:22px 20px;margin:22px 0 4px}
.phead .no{display:inline-block;font-family:Bahnschrift,Arial,sans-serif;font-weight:700;color:#fcd34d;letter-spacing:1px;font-size:14px}
.phead h1{margin:2px 0 6px;font-size:clamp(26px,6vw,38px);line-height:1.2}
.phead p{margin:0 0 14px;color:#dfe7f6;font-size:17px}
.trio{display:grid;gap:10px;grid-template-columns:1fr}
@media(min-width:720px){.trio{grid-template-columns:repeat(3,1fr)}}
.trio div{background:rgba(255,255,255,.1);border:1px solid rgba(255,255,255,.22);border-radius:12px;padding:10px 14px;font-size:15px;color:#e6edf9}
.trio b{display:block;color:#fcd34d;font-size:14px;margin-bottom:2px}

.st h4{font-size:16px;margin:18px 0 6px;color:var(--navy2)}