/* ==========================================================================
   API2GPT — 设计系统  (方向 C · 大字编辑风)
   字体: Sora + JetBrains Mono + PingFang SC 栈
   配色: ink-on-paper + 单一电光靛紫强调 (OKLCH)
   ========================================================================== */

:root{
  /* surfaces */
  --canvas:oklch(0.98 0.005 270);
  --paper:oklch(0.965 0.006 270);
  --surface:oklch(1 0 0);
  /* text */
  --ink:oklch(0.18 0.02 270);
  --ink-2:oklch(0.33 0.018 270);
  --muted:oklch(0.5 0.014 270);
  /* lines */
  --line:oklch(0.86 0.01 270);
  --line-soft:oklch(0.92 0.008 270);
  /* accent */
  --accent:oklch(0.54 0.21 272);
  --accent-press:oklch(0.47 0.21 272);
  --accent-soft:oklch(0.94 0.04 272);
  --accent-ink:oklch(0.44 0.17 272);
  /* semantic */
  --ok:oklch(0.6 0.15 158);
  --warn:oklch(0.62 0.16 60);
  /* radius scale (committed) */
  --r-s:8px; --r-m:14px; --r-l:26px; --r-pill:999px;
  /* layout */
  --maxw:1200px;
  --shadow:0 2px 6px rgba(25,20,60,.06), 0 20px 50px -22px rgba(35,25,90,.28);
  --shadow-sm:0 1px 2px rgba(25,20,60,.06), 0 8px 22px -14px rgba(35,25,90,.24);
  /* fonts */
  --font-zh:"PingFang SC","HarmonyOS Sans SC","Microsoft YaHei",sans-serif;
  --font:"Sora",var(--font-zh);
  --mono:"JetBrains Mono",ui-monospace,SFMono-Regular,Menlo,monospace;
}

*{box-sizing:border-box;margin:0;padding:0}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}}
body{
  font-family:var(--font);background:var(--canvas);color:var(--ink);line-height:1.5;
  -webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;
  text-rendering:optimizeLegibility;overflow-x:hidden;
}
a{color:inherit;text-decoration:none}
img{display:block;max-width:100%}
h1,h2,h3{font-weight:800;line-height:1;letter-spacing:-0.035em;text-wrap:balance}
p{text-wrap:pretty}
:focus-visible{outline:2.5px solid var(--accent);outline-offset:3px;border-radius:4px}

.wrap{max-width:var(--maxw);margin:0 auto;padding:0 28px}
.skip{position:absolute;left:-9999px;background:var(--ink);color:#fff;padding:10px 16px;z-index:100;font-size:14px}
.skip:focus{left:16px;top:16px}
.eyebrow{font-family:var(--mono);font-size:13px;color:var(--accent-ink);text-transform:uppercase;letter-spacing:0.05em;display:inline-flex;align-items:center;gap:10px}
.eyebrow.line::before{content:"";width:34px;height:1.5px;background:var(--accent)}

/* ---------- buttons ---------- */
.btn{font-family:var(--font);font-weight:700;font-size:15px;border:none;cursor:pointer;border-radius:var(--r-pill);
  padding:13px 24px;display:inline-flex;align-items:center;gap:8px;letter-spacing:-0.01em;
  transition:transform .12s ease, background .16s ease, box-shadow .16s ease, color .16s ease;touch-action:manipulation}
.btn:active{transform:scale(.96)}
.btn-primary{background:var(--accent);color:#fff;box-shadow:0 10px 28px -12px var(--accent)}
.btn-ink{background:var(--ink);color:#fff}
.btn-line{background:transparent;color:var(--ink);box-shadow:inset 0 0 0 1.5px var(--ink)}
.btn-sm{padding:9px 18px;font-size:14px}
@media(hover:hover){
  .btn-primary:hover{background:var(--accent-press)}
  .btn-ink:hover{background:oklch(0.28 0.02 270)}
  .btn-line:hover{background:var(--ink);color:#fff}
}

/* ---------- nav ---------- */
.nav{position:sticky;top:0;z-index:60;background:color-mix(in oklch,var(--canvas) 82%,transparent);
  backdrop-filter:blur(10px) saturate(140%);border-bottom:1px solid var(--line)}
.nav .row{display:flex;align-items:center;height:66px;gap:22px}
.brand{font-weight:800;font-size:19px;letter-spacing:-0.04em;text-transform:uppercase}
.brand .ac{color:var(--accent)}
.nav nav{display:flex;gap:24px;margin-left:auto}
.nav nav a{font-family:var(--mono);font-size:13px;color:var(--ink-2);font-weight:500;text-transform:uppercase;letter-spacing:0.02em;transition:color .15s;position:relative;padding:4px 0}
.nav nav a[aria-current="page"]{color:var(--accent)}
.nav nav a[aria-current="page"]::after{content:"";position:absolute;left:0;right:0;bottom:-2px;height:1.5px;background:var(--accent)}
@media(hover:hover){.nav nav a:hover{color:var(--accent)}}
.nav .cta{margin-left:22px}
.hamb{margin-left:auto;display:none;width:42px;height:42px;border:1.5px solid var(--ink);background:transparent;border-radius:10px;cursor:pointer;align-items:center;justify-content:center;flex-direction:column;gap:5px}
.hamb span{width:18px;height:2px;background:var(--ink);display:block;transition:transform .2s ease,opacity .2s ease}
.nav.open .hamb span:nth-child(1){transform:translateY(7px) rotate(45deg)}
.nav.open .hamb span:nth-child(2){opacity:0}
.nav.open .hamb span:nth-child(3){transform:translateY(-7px) rotate(-45deg)}
.mobile-menu{display:none;border-top:1px solid var(--line);background:var(--canvas)}
.mobile-menu a{display:block;padding:15px 28px;font-family:var(--mono);font-size:14px;text-transform:uppercase;color:var(--ink-2);border-bottom:1px solid var(--line-soft)}
.mobile-menu .btn{margin:16px 28px;display:flex;justify-content:center}
.nav.open .mobile-menu{display:block}
@media(max-width:880px){
  .nav nav,.nav .cta{display:none}
  .hamb{display:flex}
}

/* ---------- sections ---------- */
.section{padding:74px 0}
.shead{display:flex;justify-content:space-between;align-items:flex-end;gap:24px;flex-wrap:wrap}
.eyebrow2{font-family:var(--mono);font-size:12.5px;color:var(--accent-ink);text-transform:uppercase;letter-spacing:0.05em}
.sec-title{font-size:clamp(30px,4.4vw,56px);font-weight:800;letter-spacing:-0.04em;margin-top:10px;line-height:1.0}
.sec-sub{color:var(--muted);max-width:46ch;font-size:15.5px;line-height:1.6}

/* ---------- page header (subpages) ---------- */
.phead{padding:64px 0 40px;border-bottom:2px solid var(--ink)}
.phead h1{font-size:clamp(40px,7vw,84px);font-weight:800;letter-spacing:-0.045em;margin-top:18px}
.phead h1 .ac{color:var(--accent)}
.phead .lede{color:var(--ink-2);max-width:52ch;margin-top:18px;font-size:clamp(15px,1.4vw,18px);line-height:1.55}

/* ---------- model marquee ---------- */
.marq{border-top:2px solid var(--ink);border-bottom:2px solid var(--ink);overflow:hidden;background:var(--ink);color:var(--canvas)}
.marq .track{display:flex;padding:16px 0;white-space:nowrap;width:max-content;animation:scroll 60s linear infinite}
.marq .track span{font-weight:700;font-size:22px;letter-spacing:-0.02em;display:inline-flex;align-items:center;gap:14px;margin-right:40px}
.marq .track span::after{content:"✦";color:var(--accent);font-size:15px}
@keyframes scroll{from{transform:translateX(0)}to{transform:translateX(-50%)}}

/* ---------- numbered editorial blocks ---------- */
.blocks{border-top:1px solid var(--line)}
.blk{display:grid;grid-template-columns:90px 1fr 1.1fr;gap:30px;padding:34px 0;border-bottom:1px solid var(--line);align-items:start;transition:background .2s ease}
@media(hover:hover){.blk:hover{background:var(--paper)}}
.blk .no{font-family:var(--mono);font-size:15px;color:var(--accent);font-weight:700}
.blk h3{font-size:clamp(24px,3vw,34px);font-weight:800;letter-spacing:-0.03em}
.blk p{font-size:15.5px;color:var(--ink-2);line-height:1.6;max-width:50ch}
.blk .big{font-size:clamp(40px,6vw,72px);font-weight:800;letter-spacing:-0.04em;color:var(--accent);line-height:1;font-variant-numeric:tabular-nums}

/* ---------- code block ---------- */
.codewrap{display:grid;grid-template-columns:1fr 1.15fr;border:2px solid var(--ink);border-radius:var(--r-l);overflow:hidden}
.code-left{padding:40px;background:var(--ink);color:var(--canvas)}
.code-left .eyebrow2{color:oklch(0.8 0.12 272)}
.code-left h3{font-size:clamp(26px,3vw,40px);margin-top:12px;color:#fff;line-height:1.02}
.code-left p{color:rgba(255,255,255,.7);margin-top:14px;font-size:15px;line-height:1.6;max-width:38ch}
.code-left .btn{margin-top:24px}
.code-right{background:var(--surface);padding:30px 28px;font-family:var(--mono);font-size:14px;line-height:1.85;white-space:pre;overflow-x:auto}
.tk-key{color:var(--accent)}.tk-str{color:oklch(0.5 0.13 158)}.tk-com{color:var(--muted)}.tk-del{color:oklch(0.55 0.16 25)}.tk-fn{color:oklch(0.5 0.16 300)}

/* ---------- accent band ---------- */
.band{background:var(--accent);color:#fff;border-radius:var(--r-l);padding:52px 44px;display:grid;grid-template-columns:1fr auto;gap:30px;align-items:center}
.band .k{font-family:var(--mono);font-size:13px;color:rgba(255,255,255,.8);text-transform:uppercase;letter-spacing:0.05em}
.band h3{font-size:clamp(28px,4vw,46px);margin-top:10px;letter-spacing:-0.04em}
.band p{color:rgba(255,255,255,.85);margin-top:12px;max-width:50ch;font-size:15.5px}
.band .btn{background:#fff;color:var(--accent)}
@media(hover:hover){.band .btn:hover{background:oklch(0.95 0.02 272)}}
.chips{display:flex;gap:8px;margin-top:18px;flex-wrap:wrap}
.chips span{font-family:var(--mono);font-size:12.5px;background:rgba(255,255,255,.16);padding:5px 12px;border-radius:var(--r-pill)}

/* ---------- tables (pricing) ---------- */
.tablewrap{border:2px solid var(--ink);border-radius:var(--r-l);overflow:hidden;background:var(--surface)}
.ptable{width:100%;border-collapse:collapse;font-size:14.5px}
.ptable thead th{text-align:left;font-family:var(--mono);font-size:12px;text-transform:uppercase;letter-spacing:0.03em;color:var(--canvas);font-weight:500;padding:16px 22px;background:var(--ink)}
.ptable th.num,.ptable td.num{text-align:right;font-variant-numeric:tabular-nums;font-family:var(--mono)}
.ptable tbody td{padding:16px 22px;border-bottom:1px solid var(--line-soft)}
.ptable tbody tr:last-child td{border-bottom:none}
@media(hover:hover){.ptable tbody tr:hover{background:var(--paper)}}
.mname{display:flex;align-items:center;gap:11px;font-weight:700}
.mk{flex:none;width:26px;height:26px;border-radius:7px;color:#fff;font-weight:800;font-size:12px;display:grid;place-items:center}
.off{color:var(--ok);font-weight:700;font-size:13px;font-family:var(--mono)}
.pnote{font-size:12.5px;color:var(--muted);padding:14px 22px;background:var(--paper);text-align:right;font-family:var(--mono)}

/* ---------- cards grid (apps) ---------- */
.cardgrid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}
.appcard{border:2px solid var(--ink);border-radius:var(--r-m);padding:24px;background:var(--surface);transition:transform .18s ease,box-shadow .18s ease}
@media(hover:hover){.appcard:hover{transform:translateY(-4px);box-shadow:var(--shadow)}}
.appcard .ic{width:40px;height:40px;border-radius:10px;background:var(--accent-soft);color:var(--accent-ink);display:grid;place-items:center;font-weight:800;font-family:var(--mono);font-size:16px;margin-bottom:16px}
.appcard h3{font-size:18px;font-weight:700;letter-spacing:-0.02em}
.appcard .tagrow{margin-top:8px;display:flex;gap:6px;flex-wrap:wrap}
.appcard .tagrow b{font-family:var(--mono);font-size:11px;font-weight:500;color:var(--muted);background:var(--paper);border:1px solid var(--line);padding:2px 8px;border-radius:var(--r-pill)}
.appcard p{font-size:14px;color:var(--ink-2);margin-top:12px;line-height:1.55}
.appcard .lk{margin-top:14px;font-family:var(--mono);font-size:12.5px;color:var(--accent);font-weight:500;display:inline-flex;gap:6px}

/* ---------- faq accordion ---------- */
.acc{border-top:1px solid var(--line)}
.acc details{border-bottom:1px solid var(--line)}
.acc summary{list-style:none;cursor:pointer;padding:24px 0;display:flex;justify-content:space-between;align-items:center;gap:20px;font-size:clamp(17px,2vw,21px);font-weight:700;letter-spacing:-0.02em}
.acc summary::-webkit-details-marker{display:none}
.acc summary .pm{flex:none;width:30px;height:30px;border:1.5px solid var(--line);border-radius:8px;display:grid;place-items:center;position:relative;transition:border-color .18s,background .18s}
.acc summary .pm::before,.acc summary .pm::after{content:"";position:absolute;background:var(--ink);transition:transform .2s ease,background .18s}
.acc summary .pm::before{width:12px;height:2px}
.acc summary .pm::after{width:2px;height:12px}
.acc details[open] summary .pm{border-color:var(--accent);background:var(--accent)}
.acc details[open] summary .pm::before,.acc details[open] summary .pm::after{background:#fff}
.acc details[open] summary .pm::after{transform:scaleY(0)}
@media(hover:hover){.acc summary:hover{color:var(--accent)}}
.acc .answer{padding:0 0 26px;color:var(--ink-2);font-size:15.5px;line-height:1.65;max-width:68ch}
.acc .answer code{font-family:var(--mono);font-size:13.5px;background:var(--paper);border:1px solid var(--line);padding:1px 7px;border-radius:6px}

/* ---------- docs layout ---------- */
.doclayout{display:grid;grid-template-columns:230px 1fr;gap:50px;align-items:start;padding-top:44px}
.docnav{position:sticky;top:90px;font-size:14px}
.docnav h5{font-family:var(--mono);font-size:11.5px;text-transform:uppercase;letter-spacing:0.04em;color:var(--muted);margin:0 0 10px}
.docnav ul{list-style:none;display:flex;flex-direction:column;gap:2px;margin-bottom:24px}
.docnav a{display:block;padding:7px 12px;border-radius:8px;color:var(--ink-2);transition:background .15s,color .15s}
.docnav a[aria-current="true"]{background:var(--accent-soft);color:var(--accent-ink);font-weight:600}
@media(hover:hover){.docnav a:hover{background:var(--paper);color:var(--ink)}}
.doc article{min-width:0}
.doc article h2{font-size:clamp(26px,3.4vw,38px);font-weight:800;letter-spacing:-0.03em;margin:48px 0 16px;scroll-margin-top:90px;line-height:1.05}
.doc article h2:first-child{margin-top:0}
.doc article h3{font-size:20px;font-weight:700;margin:30px 0 10px;letter-spacing:-0.02em}
.doc article p{color:var(--ink-2);font-size:15.5px;line-height:1.7;margin:12px 0;max-width:70ch}
.doc article ul,.doc article ol{margin:12px 0 12px 22px;color:var(--ink-2);font-size:15.5px;line-height:1.7}
.doc article li{margin:6px 0}
.doc article code{font-family:var(--mono);font-size:13.5px;background:var(--paper);border:1px solid var(--line);padding:1px 7px;border-radius:6px}
.codeblock{background:var(--ink);color:oklch(0.92 0.01 270);border-radius:var(--r-m);padding:20px 22px;font-family:var(--mono);font-size:13.5px;line-height:1.8;white-space:pre;overflow-x:auto;margin:16px 0;position:relative}
.codeblock .tk-key{color:oklch(0.78 0.16 272)}
.codeblock .tk-str{color:oklch(0.78 0.13 158)}
.codeblock .tk-com{color:oklch(0.6 0.01 270)}
.copy-btn{position:absolute;top:12px;right:12px;font-family:var(--mono);font-size:11.5px;color:rgba(255,255,255,.7);background:rgba(255,255,255,.1);border:none;border-radius:6px;padding:5px 10px;cursor:pointer;transition:background .15s}
@media(hover:hover){.copy-btn:hover{background:rgba(255,255,255,.2)}}
.callout{border:1.5px solid var(--line);border-radius:var(--r-m);padding:16px 18px;margin:18px 0;font-size:14.5px;color:var(--ink-2);background:var(--paper);line-height:1.6}
.callout b{color:var(--ink)}

/* ---------- final cta ---------- */
.final{padding:90px 0;text-align:center}
.final h2{font-size:clamp(40px,7vw,96px);font-weight:800;letter-spacing:-0.045em}
.final h2 .ac{color:var(--accent)}
.final p{font-family:var(--mono);color:var(--muted);margin-top:18px;font-size:14px;text-transform:uppercase;letter-spacing:0.04em}
.final .cta-row{display:flex;gap:12px;justify-content:center;margin-top:30px;flex-wrap:wrap}

/* ---------- footer ---------- */
footer{border-top:2px solid var(--ink);padding:46px 0 34px}
.foot{display:grid;grid-template-columns:2fr 1fr 1fr 1fr;gap:30px}
.foot .brand{display:block;margin-bottom:12px;font-size:24px}
.foot p{font-size:13px;color:var(--muted);max-width:30ch;line-height:1.55}
.foot h5{font-family:var(--mono);font-size:12px;text-transform:uppercase;letter-spacing:0.04em;color:var(--ink-2);margin-bottom:12px;font-weight:700}
.foot ul{list-style:none;display:flex;flex-direction:column;gap:9px}
.foot ul a{font-size:14px;color:var(--muted);transition:color .15s}
@media(hover:hover){.foot ul a:hover{color:var(--accent)}}
.foot-base{display:flex;justify-content:space-between;border-top:1px solid var(--line);margin-top:32px;padding-top:18px;font-size:12.5px;color:var(--muted);font-family:var(--mono);flex-wrap:wrap;gap:8px}

/* ---------- enter animation ---------- */
@keyframes rise{from{opacity:0;transform:translateY(16px)}to{opacity:1;transform:none}}
.anim{animation:rise .7s cubic-bezier(0.16,1,0.3,1) both}
.d1{animation-delay:.05s}.d2{animation-delay:.14s}.d3{animation-delay:.24s}.d4{animation-delay:.34s}.d5{animation-delay:.44s}
@media(prefers-reduced-motion:reduce){
  *{animation:none!important;transition:none!important}
  .marq .track{animation:none}
}

/* ---------- responsive ---------- */
@media(max-width:900px){
  .codewrap,.band,.foot{grid-template-columns:1fr;gap:28px}
  .blk{grid-template-columns:50px 1fr;gap:18px}
  .blk p{grid-column:2}
  .code-left{border-radius:0}
  .cardgrid{grid-template-columns:1fr 1fr}
  .doclayout{grid-template-columns:1fr;gap:24px}
  .docnav{position:static;display:flex;gap:20px;overflow-x:auto;padding-bottom:8px;border-bottom:1px solid var(--line)}
  .docnav ul{flex-direction:row;margin-bottom:0;white-space:nowrap}
  .docnav h5{display:none}
}
@media(max-width:560px){
  .wrap{padding:0 20px}
  .foot{grid-template-columns:1fr 1fr}
  .cardgrid{grid-template-columns:1fr}
  .blk .big{font-size:48px}
  .band{padding:36px 26px}
  .code-left{padding:30px 26px}
  .ptable thead{display:none}
  .ptable tbody td{display:flex;justify-content:space-between;padding:11px 18px;border:none}
  .ptable tbody tr{display:block;border-bottom:1.5px solid var(--line);padding:10px 0}
  .ptable td.num::before{content:attr(data-label);font-family:var(--mono);font-size:11px;text-transform:uppercase;color:var(--muted);font-weight:500}
  .ptable td[data-label="模型"]::before{content:""}
}