/* AI Gateway Lab — control-room glass. Hand-rolled, no framework.
 * Themes: [data-theme=light|dark], absent = system (media query).
 * Surfaces: [data-surface=graphite|midnight], absent = frost.
 * Glass budget: nav + hero console + demo panels + key cards only. */

/* ---------- tokens: dark (default values) ---------- */
:root {
  --bg0: #0c1016; --bg1: #131922;
  --wash-a: rgba(56, 116, 200, 0.14); --wash-b: rgba(90, 70, 180, 0.10);
  --grid: rgba(255, 255, 255, 0.028);
  --glass: rgba(19, 26, 36, 0.66); --glass-brd: rgba(255, 255, 255, 0.09);
  --glass-hi: rgba(255, 255, 255, 0.05);
  --panel: #171e29; --border: #2b3442;
  --text: #e8edf4; --dim: #9aa7b8;
  --accent: #6cb2ff; --accent-ink: #0b1420;
  --ok: #4cc366; --warn: #d9a13c; --fail: #f2635c;
  --shadow: 0 10px 30px rgba(0, 0, 0, 0.35);
  --ring: #8cc2ff;
  --mono: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  color-scheme: dark;
}

/* ---------- tokens: light ---------- */
@media (prefers-color-scheme: light) {
  :root:not([data-theme="dark"]) {
    --bg0: #f2f5f9; --bg1: #e9eef5;
    --wash-a: rgba(70, 130, 210, 0.12); --wash-b: rgba(120, 100, 200, 0.08);
    --grid: rgba(20, 40, 70, 0.045);
    --glass: rgba(255, 255, 255, 0.62); --glass-brd: rgba(30, 50, 80, 0.14);
    --glass-hi: rgba(255, 255, 255, 0.75);
    --panel: #ffffff; --border: #d3dce7;
    --text: #1a2330; --dim: #4c5a6c;
    --accent: #175db6; --accent-ink: #ffffff;
    --ok: #187438; --warn: #8a5a00; --fail: #b3261e;
    --shadow: 0 10px 28px rgba(30, 50, 80, 0.12);
    --ring: #175db6;
    color-scheme: light;
  }
}
:root[data-theme="light"] {
  --bg0: #f2f5f9; --bg1: #e9eef5;
  --wash-a: rgba(70, 130, 210, 0.12); --wash-b: rgba(120, 100, 200, 0.08);
  --grid: rgba(20, 40, 70, 0.045);
  --glass: rgba(255, 255, 255, 0.62); --glass-brd: rgba(30, 50, 80, 0.14);
  --glass-hi: rgba(255, 255, 255, 0.75);
  --panel: #ffffff; --border: #d3dce7;
  --text: #1a2330; --dim: #4c5a6c;
  --accent: #175db6; --accent-ink: #ffffff;
  --ok: #187438; --warn: #8a5a00; --fail: #b3261e;
  --shadow: 0 10px 28px rgba(30, 50, 80, 0.12);
  --ring: #175db6;
  color-scheme: light;
}

/* ---------- surfaces ---------- */
/* graphite: neutral, cooler-free grey */
:root[data-surface="graphite"] {
  --wash-a: rgba(140, 150, 165, 0.10); --wash-b: rgba(110, 115, 130, 0.08);
}
:root[data-surface="graphite"]:not([data-theme="light"]) { --bg0: #101214; --bg1: #16191d; --panel: #191d22; --border: #30363c; --accent: #7fb4e8; }
@media (prefers-color-scheme: light) {
  :root[data-surface="graphite"]:not([data-theme="dark"]) { --bg0: #f4f4f5; --bg1: #ebeced; --accent: #24567e; }
}
:root[data-surface="graphite"][data-theme="light"] { --bg0: #f4f4f5; --bg1: #ebeced; --accent: #24567e; }

/* midnight: deep indigo (dark) / blue-tinted paper (light) */
:root[data-surface="midnight"] {
  --wash-a: rgba(70, 80, 220, 0.16); --wash-b: rgba(140, 60, 190, 0.10);
}
:root[data-surface="midnight"]:not([data-theme="light"]) { --bg0: #0a0d1c; --bg1: #111530; --panel: #141833; --border: #2b3153; --accent: #8fa6ff; }
@media (prefers-color-scheme: light) {
  :root[data-surface="midnight"]:not([data-theme="dark"]) { --bg0: #eef0fa; --bg1: #e4e8f7; --accent: #3947b0; }
}
:root[data-surface="midnight"][data-theme="light"] { --bg0: #eef0fa; --bg1: #e4e8f7; --accent: #3947b0; }

/* ---------- base ---------- */
* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  background:
    radial-gradient(1100px 500px at 12% -8%, var(--wash-a), transparent 60%),
    radial-gradient(900px 460px at 95% 4%, var(--wash-b), transparent 55%),
    linear-gradient(var(--grid) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid) 1px, transparent 1px),
    var(--bg0);
  background-size: auto, auto, 44px 44px, 44px 44px, auto;
  background-attachment: fixed;
  color: var(--text);
  font: 16px/1.65 -apple-system, "Segoe UI", Roboto, sans-serif;
  min-height: 100vh;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
main p a, main li a, main td a, .notice a { text-decoration: underline; text-underline-offset: 2px; }
main p a.btn { text-decoration: none; }
code, pre { font-family: var(--mono); font-size: 0.92em; }
pre { background: var(--bg1); border: 1px solid var(--border); border-radius: 10px; padding: 16px; overflow-x: auto; margin: 16px 0; }
code { background: var(--bg1); padding: 2px 6px; border-radius: 5px; }
pre code { background: none; padding: 0; }

:focus-visible { outline: 2px solid var(--ring); outline-offset: 2px; border-radius: 4px; }

/* ---------- utilities ---------- */
.visually-hidden {
  position: absolute; width: 1px; height: 1px; margin: -1px; padding: 0;
  overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0;
}
.skip-link {
  position: absolute; left: 8px; top: -48px; z-index: 20;
  background: var(--panel); color: var(--text); border: 1px solid var(--border);
  border-radius: 8px; padding: 8px 14px; transition: top 0.1s;
}
.skip-link:focus { top: 8px; }

/* ---------- nav (glass #1) ---------- */
nav { position: sticky; top: 0; z-index: 10; background: var(--glass); border-bottom: 1px solid var(--glass-brd); }
@supports (backdrop-filter: blur(1px)) or (-webkit-backdrop-filter: blur(1px)) {
  nav { -webkit-backdrop-filter: blur(12px) saturate(1.35); backdrop-filter: blur(12px) saturate(1.35); }
}
.nav-inner { max-width: 1160px; margin: 0 auto; padding: 12px 24px; display: flex; align-items: center; gap: 14px 16px; flex-wrap: wrap; }
.nav-inner .brand { font-weight: 700; color: var(--text); font-size: 16.5px; }
.nav-inner .brand span { color: var(--accent); }
nav a.nl { color: var(--dim); font-size: 14px; padding: 3px 2px; }
nav a.nl:hover, nav a.nl.active { color: var(--text); text-decoration: none; }
nav a.nl.lang { border: 1px solid var(--border); border-radius: 7px; padding: 7px 10px; font-family: var(--mono); font-size: 12.5px; min-height: 32px; display: inline-flex; align-items: center; }
nav a.nl.lang:hover { border-color: var(--accent); color: var(--accent); }

/* CJK-aware font stack for the Chinese tree */
html[lang="zh-Hans"] body {
  font-family: -apple-system, "Segoe UI", Roboto, "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
}
html[lang="zh-Hans"] h1 { letter-spacing: 0; }
.theme-cluster { margin-left: auto; display: flex; gap: 8px; align-items: center; }
.theme-btn {
  font: 12.5px/1 var(--mono); color: var(--dim); background: transparent;
  border: 1px solid var(--border); border-radius: 7px; padding: 7px 10px; cursor: pointer;
  min-height: 32px;
}
.theme-btn:hover { color: var(--text); border-color: var(--dim); }
/* custom-styled select: kill native chrome, add our own caret */
.sel-wrap { position: relative; display: inline-flex; align-items: center; }
.sel-wrap::after {
  content: ""; position: absolute; right: 9px; pointer-events: none;
  width: 7px; height: 7px; border-right: 1.5px solid var(--dim);
  border-bottom: 1.5px solid var(--dim); transform: rotate(45deg) translateY(-2px);
}
.theme-sel {
  -webkit-appearance: none; -moz-appearance: none; appearance: none;
  font: 12.5px/1 var(--mono); color: var(--dim); background: transparent;
  border: 1px solid var(--border); border-radius: 7px; padding: 7px 24px 7px 10px;
  cursor: pointer; min-height: 32px;
}
.theme-sel:hover { color: var(--text); border-color: var(--dim); }
.theme-sel option { background: var(--panel); color: var(--text); }
.no-js .theme-cluster { display: none; }

/* ---------- layout ---------- */
main { max-width: 1080px; margin: 0 auto; padding: 52px 24px 80px; }
h1 { font-size: clamp(1.7rem, 3.6vw, 2.3rem); line-height: 1.22; margin-bottom: 12px; letter-spacing: -0.01em; }
h2 { font-size: 1.45rem; margin: 44px 0 12px; letter-spacing: -0.005em; }
h3 { font-size: 1.12rem; margin: 24px 0 8px; }
p, ul, ol { margin-bottom: 14px; }
ul, ol { padding-left: 24px; }
.dim { color: var(--dim); }
.lead { font-size: 1.15rem; color: var(--dim); max-width: 720px; }
.kicker { font: 600 12px/1 var(--mono); letter-spacing: 0.12em; text-transform: uppercase; color: var(--accent); margin-bottom: 8px; }

td.ok-cell { color: var(--ok); }

/* ---------- hero ---------- */
.hero { display: grid; gap: 36px; align-items: start; margin-bottom: 28px; }
@media (min-width: 980px) { .hero-console { margin-top: 34px; } }
@media (min-width: 980px) { .hero { grid-template-columns: 7fr 5fr; } }
.hero-console {
  background: var(--glass); border: 1px solid var(--glass-brd); border-radius: 16px;
  box-shadow: var(--shadow); overflow: hidden;
}
@supports (backdrop-filter: blur(1px)) or (-webkit-backdrop-filter: blur(1px)) {
  .hero-console { -webkit-backdrop-filter: blur(14px) saturate(1.3); backdrop-filter: blur(14px) saturate(1.3); }
}
.hero-console .hc-bar {
  display: flex; align-items: center; gap: 8px; padding: 10px 14px;
  border-bottom: 1px solid var(--glass-brd); background: var(--glass-hi);
  font: 12px/1 var(--mono); color: var(--dim);
}
.hc-dot { width: 10px; height: 10px; border-radius: 50%; background: var(--border); }
.hero-console pre {
  background: transparent; border: none; margin: 0; padding: 16px 18px;
  font-size: 12.8px; line-height: 1.75; border-radius: 0;
}
.hc-c { color: var(--dim); opacity: 0.95; } .hc-k { color: var(--accent); } .hc-o { color: var(--ok); }
@media (max-width: 640px) { .hero-console pre { font-size: 12px; padding: 14px 12px; } }

/* ---------- buttons ---------- */
.btn {
  display: inline-block; background: var(--accent); color: var(--accent-ink);
  font-weight: 600; padding: 11px 22px; border-radius: 9px; border: 1px solid transparent;
  cursor: pointer; transition: filter 0.12s, transform 0.06s;
}
.btn:hover { filter: brightness(1.08); text-decoration: none; }
.btn:active { transform: translateY(1px); }
.btn.ghost { background: transparent; color: var(--accent); border-color: var(--border); }
.btn.ghost:hover { border-color: var(--accent); }
.cta-row { margin-top: 22px; }
.btn-gap { margin-left: 10px; }

/* ---------- cards ---------- */
.grid { display: grid; gap: 18px; margin: 24px 0; }
.grid.c2 { grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); }
.grid.c3 { grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); }
.card { background: var(--panel); border: 1px solid var(--border); border-radius: 12px; padding: 20px; }
.card h3 { margin-top: 0; }
.card.glass { background: var(--glass); border-color: var(--glass-brd); box-shadow: var(--shadow); }
@supports (backdrop-filter: blur(1px)) or (-webkit-backdrop-filter: blur(1px)) {
  .card.glass { -webkit-backdrop-filter: blur(10px) saturate(1.25); backdrop-filter: blur(10px) saturate(1.25); }
}

/* ---------- tables / tags / notice ---------- */
table { width: 100%; border-collapse: collapse; margin: 16px 0; font-size: 14.5px; display: block; overflow-x: auto; -webkit-overflow-scrolling: touch; scrollbar-width: thin; scrollbar-color: var(--border) transparent; }
table::-webkit-scrollbar { height: 6px; }
table::-webkit-scrollbar-thumb { background: var(--border); border-radius: 3px; }
th, td { text-align: left; padding: 9px 12px; border-bottom: 1px solid var(--border); vertical-align: top; }
th { color: var(--dim); font-weight: 600; white-space: nowrap; }
td code { white-space: nowrap; overflow-wrap: normal; }
code { overflow-wrap: anywhere; }
.scroll-x { overflow-x: auto; }

.tag { display: inline-block; font-size: 12px; font-family: var(--mono); padding: 1px 8px; border-radius: 10px; border: 1px solid var(--border); }
.tag.ok { color: var(--ok); border-color: var(--ok); }
.tag.warn { color: var(--warn); border-color: var(--warn); }
.tag.fail { color: var(--fail); border-color: var(--fail); }
.tag.dim { color: var(--dim); }

.notice { background: var(--bg1); border-left: 3px solid var(--warn); padding: 12px 16px; border-radius: 0 10px 10px 0; margin: 18px 0; font-size: 14.5px; color: var(--dim); }
footer { border-top: 1px solid var(--border); margin-top: 40px; background: var(--bg1); }
.foot-inner { max-width: 1080px; margin: 0 auto; padding: 28px 24px; color: var(--dim); font-size: 13.5px; }

.diagram { font-family: var(--mono); font-size: 13px; line-height: 1.5; background: var(--bg1); border: 1px solid var(--border); border-radius: 10px; padding: 20px; overflow-x: auto; white-space: pre; color: var(--text); }

/* ---------- demo (glass panels) ---------- */
.demo-toolbar { display: flex; gap: 12px; align-items: center; flex-wrap: wrap; margin-bottom: 18px; }
.stat { font-family: var(--mono); font-size: 13px; }
#demo-root table { font-family: var(--mono); font-size: 13px; }
.bar { height: 8px; background: var(--bg0); border: 1px solid var(--border); border-radius: 4px; overflow: hidden; width: 120px; display: inline-block; vertical-align: middle; }
.bar > i { display: block; height: 100%; background: var(--accent); }
.bar > i.hot { background: var(--fail); }

/* ---------- responsive ---------- */
@media (max-width: 640px) {
  h1 { font-size: 1.55rem; }
  .nav-inner { gap: 10px 14px; padding: 10px 16px 8px; }
  .theme-cluster { margin-left: 0; width: 100%; padding-top: 8px; border-top: 1px solid var(--glass-brd); }
  main { padding: 32px 16px 60px; }
  .hero { gap: 24px; }
}

/* ---------- reduced motion ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { transition: none !important; animation: none !important; }
}