:root {
  color-scheme: light;
  --page: #f7f8fa; --surface: #ffffff; --surface-2: #f2f4f7; --line: rgba(15, 23, 42, .09);
  --text: #111418; --text-2: #4a5160; --muted: #7b8291;
  --accent: #2a78d6; --accent-soft: rgba(42, 120, 214, .09);
  --code-bg: #0f1420; --code-text: #e3e8f0; --code-muted: #8a94a8; --code-key: #7cc4ff; --code-str: #a5e3a1; --code-num: #f5c37a; --code-kw: #d7a6ff; --code-com: #6f7a8f;
  --get: #1f7a46; --get-bg: rgba(31, 122, 70, .1); --post: #2a68c9; --post-bg: rgba(42, 104, 201, .1);
  --put: #9a5b00; --put-bg: rgba(250, 178, 25, .16); --patch: #7a4fc4; --patch-bg: rgba(122, 79, 196, .1);
  --delete: #b42a2a; --delete-bg: rgba(208, 59, 59, .1);
  --ok: #1f7a46; --bad: #b42a2a; --warn-bg: rgba(250, 178, 25, .14); --safe-bg: rgba(31, 122, 70, .08);
  --shadow: 0 1px 2px rgba(16, 24, 40, .04), 0 6px 20px rgba(16, 24, 40, .05);
}
@media (prefers-color-scheme: dark) {
  :root {
    color-scheme: dark;
    --page: #0c0e12; --surface: #151820; --surface-2: #1c2029; --line: rgba(255, 255, 255, .08);
    --text: #eef0f4; --text-2: #b8bfcc; --muted: #8a92a2;
    --accent: #5aa2f0; --accent-soft: rgba(90, 162, 240, .12);
    --code-bg: #0a0d14;
    --get: #4cc47f; --get-bg: rgba(76, 196, 127, .12); --post: #6aa8f5; --post-bg: rgba(106, 168, 245, .12);
    --put: #f0b84a; --put-bg: rgba(240, 184, 74, .14); --patch: #b897f0; --patch-bg: rgba(184, 151, 240, .13);
    --delete: #f07a7a; --delete-bg: rgba(240, 122, 122, .13);
    --ok: #4cc47f; --bad: #f07a7a; --warn-bg: rgba(240, 184, 74, .12); --safe-bg: rgba(76, 196, 127, .09);
    --shadow: 0 1px 2px rgba(0, 0, 0, .4);
  }
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 76px; }
body { margin: 0; background: var(--page); color: var(--text); font: 16px/1.65 system-ui, -apple-system, "Segoe UI", sans-serif; -webkit-font-smoothing: antialiased; }
a { color: var(--accent); }
code, pre, .mono { font-family: ui-monospace, "SF Mono", "Cascadia Code", Menlo, Consolas, monospace; }
code { font-size: .88em; background: var(--surface-2); padding: .1em .35em; border-radius: 5px; }
h1, h2, h3 { letter-spacing: -.015em; line-height: 1.25; }
h1 { font-size: clamp(30px, 4vw, 42px); margin: 6px 0 14px; }
h2 { font-size: 28px; margin: 0 0 14px; }
h3 { font-size: 18px; margin: 22px 0 8px; }
p { margin: 0 0 14px; }

/* Top bar */
.topbar { position: sticky; top: 0; z-index: 20; display: flex; align-items: center; gap: 16px; padding: 10px 20px; background: color-mix(in srgb, var(--surface) 92%, transparent); backdrop-filter: blur(8px); border-bottom: 1px solid var(--line); }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 17px; color: var(--text); text-decoration: none; white-space: nowrap; }
.logo { display: grid; place-items: center; width: 32px; height: 32px; border-radius: 9px; background: var(--accent); color: #fff; font: 700 14px ui-monospace, monospace; }
.menu-btn { display: none; border: 1px solid var(--line); background: var(--surface); color: var(--text); border-radius: 8px; width: 38px; height: 38px; font-size: 18px; cursor: pointer; }
.token-box { margin-left: auto; display: flex; align-items: center; gap: 8px; min-width: 0; }
.token-box label { font-size: 13px; color: var(--text-2); font-weight: 600; white-space: nowrap; }
.token-box input { width: 300px; max-width: 40vw; font: 13px ui-monospace, monospace; padding: 8px 10px; border: 1px solid var(--line); border-radius: 8px; background: var(--surface); color: var(--text); }
.token-box input.set { border-color: var(--ok); }

/* Layout */
.layout { display: grid; grid-template-columns: 260px minmax(0, 1fr); max-width: 1380px; margin: 0 auto; }
.toc { position: sticky; top: 59px; height: calc(100vh - 59px); overflow-y: auto; padding: 22px 14px 40px 20px; border-right: 1px solid var(--line); font-size: 14px; }
.toc a { display: flex; align-items: center; gap: 8px; padding: 5px 10px; border-radius: 7px; color: var(--text-2); text-decoration: none; }
.toc a:hover { background: var(--surface-2); color: var(--text); }
.toc a.on { background: var(--accent-soft); color: var(--accent); font-weight: 600; }
.toc a { align-items: flex-start; }
.toc a .m { font-size: 9.5px; min-width: 44px; flex: none; margin-top: 2px; }
.toc a .p { min-width: 0; overflow-wrap: anywhere; font-family: ui-monospace, monospace; font-size: 12px; line-height: 1.45; }
.toc-group { margin: 18px 10px 6px; font-size: 11.5px; font-weight: 700; text-transform: uppercase; letter-spacing: .06em; color: var(--muted); }
.toc-sub { margin: 10px 10px 2px; font-size: 12.5px; font-weight: 600; color: var(--text); }
.content { min-width: 0; padding: 30px clamp(18px, 4vw, 56px) 80px; max-width: 1060px; }
section { padding: 34px 0 30px; border-bottom: 1px solid var(--line); }
section:last-child { border-bottom: 0; }

/* Hero */
.hero { padding-top: 10px; }
.eyebrow { color: var(--accent); font-weight: 700; font-size: 13px; text-transform: uppercase; letter-spacing: .07em; margin: 0; }
.lead { font-size: 19px; color: var(--text-2); max-width: 760px; }
.facts { display: grid; gap: 1px; background: var(--line); border: 1px solid var(--line); border-radius: 12px; overflow: hidden; margin: 22px 0; }
.facts > div { display: flex; align-items: center; gap: 14px; flex-wrap: wrap; padding: 12px 16px; background: var(--surface); }
.facts span { min-width: 90px; font-weight: 600; color: var(--muted); font-size: 13px; }
.facts code { font-size: 14px; }

/* Callouts */
.callout { padding: 14px 16px; border-radius: 12px; background: var(--accent-soft); border-left: 4px solid var(--accent); margin: 16px 0; color: var(--text-2); }
.callout.safe { background: var(--safe-bg); border-color: var(--ok); }
.callout.warn { background: var(--warn-bg); border-color: var(--put); }
.callout b { color: var(--text); }

/* Diagrams */
.diagram { margin: 18px 0 8px; padding: 14px; background: var(--surface); border: 1px solid var(--line); border-radius: 14px; }
.diagram svg { width: 100%; height: auto; display: block; }
.diagram .box { stroke-width: 1.5; }
.diagram .client { fill: var(--post-bg); stroke: var(--post); }
.diagram .server { fill: var(--get-bg); stroke: var(--get); }
.diagram .db { fill: var(--patch-bg); stroke: var(--patch); }
.diagram text { fill: var(--text); text-anchor: middle; font-family: system-ui, sans-serif; }
.diagram .t-title { font-size: 17px; font-weight: 700; }
.diagram .t-sub { font-size: 13px; fill: var(--text-2); }
.diagram .t-label { font-size: 13px; font-weight: 600; fill: var(--text-2); }
.diagram .t-note { font-size: 13px; fill: var(--muted); }
.diagram .flow { stroke: var(--text-2); stroke-width: 2; }
.diagram .flow.back { stroke-dasharray: 6 4; }
.diagram .arrowhead { fill: var(--text-2); }
.diagram .entity rect { fill: var(--surface-2); stroke: var(--line); stroke-width: 1.5; }
.diagram .e-title { font: 700 14px ui-monospace, monospace; }
.diagram .e-row { font: 12px ui-monospace, monospace; fill: var(--text-2); text-anchor: start; }
.diagram .link { stroke: var(--muted); stroke-width: 1.5; }

/* OpenAI case study visuals */
.diagram .nest { stroke-width: 1.5; }
.diagram .n0 { fill: var(--surface-2); stroke: var(--line); }
.diagram .n1 { fill: var(--surface); stroke: var(--patch); }
.diagram .n2 { fill: var(--patch-bg); stroke: var(--patch); }
.diagram .n3 { fill: var(--surface); stroke: var(--ok); stroke-width: 2.5; }
.diagram .n-title { font: 700 14px ui-monospace, monospace; text-anchor: start; }
.diagram .n-sub { font: 13px ui-monospace, monospace; fill: var(--text-2); text-anchor: start; }
.diagram .n-text { font: 600 14px ui-monospace, monospace; fill: var(--ok); text-anchor: start; }
.diagram .n-note { font: 13px system-ui, sans-serif; fill: var(--muted); text-anchor: start; }
.diagram .bubble.user { fill: var(--post-bg); stroke: var(--post); }
.diagram .bubble.asst { fill: var(--get-bg); stroke: var(--get); }
.diagram .bubble.faded { opacity: .55; }
.diagram .b-text { font: 13px ui-monospace, monospace; text-anchor: start; }
.diagram .b-note { font: 13px system-ui, sans-serif; fill: var(--muted); text-anchor: start; }
.diagram .r-head { font: 700 13px system-ui, sans-serif; fill: var(--text-2); text-anchor: start; }
.diagram .r-arrow { font-size: 20px; fill: var(--muted); }
.diagram .lane { stroke: var(--line); stroke-width: 2; stroke-dasharray: 3 5; }
.diagram .t-title.s { font-size: 15px; }
.ai-step { scroll-margin-top: 76px; }
.ai-step .ep-head h3 { font-size: 20px; }
.ai-step .after { color: var(--text-2); margin: 0; }
.token-bar { display: flex; height: 34px; border-radius: 9px; overflow: hidden; margin: 6px 0 10px; font: 600 12.5px system-ui; }
.token-bar > div { display: grid; place-items: center; color: #fff; min-width: 70px; }
.token-bar .in { background: var(--post); } .token-bar .out { background: var(--patch); }
.token-facts { display: grid; grid-template-columns: max-content 1fr; gap: 4px 14px; font-size: 14px; }
.token-facts dt { color: var(--muted); } .token-facts dd { margin: 0; font-variant-numeric: tabular-nums; }
.temp-compare { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.temp-card { border: 1px solid var(--line); border-radius: 12px; padding: 12px 14px; background: var(--surface-2); }
.temp-card h4 { margin: 0 0 8px; font-size: 14px; text-transform: none; letter-spacing: 0; color: var(--text); }
.temp-card .gauge { height: 8px; border-radius: 4px; background: var(--line); margin-bottom: 10px; overflow: hidden; }
.temp-card .gauge i { display: block; height: 100%; background: linear-gradient(90deg, var(--post), var(--put)); }
.temp-card ol { margin: 0; padding-left: 20px; font: 14px ui-monospace, monospace; }
.temp-card .verdict { font-size: 13px; color: var(--muted); margin-top: 8px; }
.exercises li { margin-bottom: 10px; }

/* Grids, steps, tables */
.two { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 20px; }
/* Grid items default to min-width: auto, so one long line would squeeze its neighbour or overflow the card. */
.two > *, .ep-body > *, .try-body > * { min-width: 0; }
.parts { padding-left: 20px; margin: 0; }
.parts li { margin-bottom: 8px; }
.label { font-size: 12px; font-weight: 700; color: var(--muted); text-transform: uppercase; letter-spacing: .05em; margin: 8px 0 6px; }
.steps { display: grid; gap: 14px; }
.step { display: flex; gap: 16px; padding: 18px; background: var(--surface); border: 1px solid var(--line); border-radius: 14px; box-shadow: var(--shadow); }
.step > div { min-width: 0; flex: 1; }
.step h3 { margin-top: 2px; }
.num { flex: none; display: grid; place-items: center; width: 32px; height: 32px; border-radius: 50%; background: var(--accent); color: #fff; font-weight: 700; }
.tbl { width: 100%; border-collapse: collapse; font-size: 14.5px; margin: 10px 0 16px; background: var(--surface); border: 1px solid var(--line); border-radius: 12px; overflow: hidden; display: block; overflow-x: auto; }
.tbl thead, .tbl tbody { display: table; width: 100%; border-collapse: collapse; }
.tbl th, .tbl td { text-align: left; padding: 9px 13px; border-bottom: 1px solid var(--line); vertical-align: top; }
.tbl th { font-size: 12.5px; color: var(--muted); font-weight: 600; background: var(--surface-2); white-space: nowrap; }
.tbl tbody th { background: none; color: var(--text); font-size: 14px; width: 160px; }
.tbl tr:last-child td, .tbl tr:last-child th { border-bottom: 0; }
.status-table td:first-child { font-family: ui-monospace, monospace; font-weight: 700; }
.status-table tr.ok td:first-child { color: var(--ok); }
.status-table tr.bad td:first-child { color: var(--put); }
.status-table tr.server td:first-child { color: var(--bad); }
.glossary { display: grid; grid-template-columns: max-content 1fr; gap: 8px 22px; }
.glossary dt { font-weight: 700; }
.glossary dd { margin: 0; color: var(--text-2); }
.footnote { color: var(--muted); font-size: 13px; margin-top: 24px; }

/* Method badges */
.m { display: inline-block; min-width: 58px; text-align: center; padding: 2px 8px; border-radius: 6px; font: 700 11.5px ui-monospace, monospace; letter-spacing: .03em; }
.m.get { color: var(--get); background: var(--get-bg); }
.m.post { color: var(--post); background: var(--post-bg); }
.m.put { color: var(--put); background: var(--put-bg); }
.m.patch { color: var(--patch); background: var(--patch-bg); }
.m.delete { color: var(--delete); background: var(--delete-bg); }

/* Code */
pre { margin: 0; }
pre.code, pre.http, pre.out { position: relative; background: var(--code-bg); color: var(--code-text); border-radius: 12px; padding: 16px 18px; overflow-x: auto; font-size: 13.5px; line-height: 1.6; }
pre.code code, pre.http code, pre.out code { background: none; padding: 0; font-size: inherit; color: inherit; }
pre.http { white-space: pre-wrap; word-break: break-word; }
pre.out { background: var(--surface-2); color: var(--text); border: 1px solid var(--line); white-space: pre-wrap; word-break: break-word; }
.tok-kw { color: var(--code-kw); } .tok-str { color: var(--code-str); } .tok-num { color: var(--code-num); }
.tok-com { color: var(--code-com); font-style: italic; } .tok-key { color: var(--code-key); } .tok-fn { color: #ffd479; }
.http .h-line { color: #fff; font-weight: 700; } .http .h-name { color: var(--code-key); } .http .h-dim { color: var(--code-muted); }
.code-wrap { position: relative; }
.copy { position: absolute; top: 8px; right: 8px; border: 1px solid rgba(255, 255, 255, .18); background: rgba(255, 255, 255, .08); color: #dfe6f0; font: 600 12px system-ui; padding: 4px 10px; border-radius: 7px; cursor: pointer; }
.copy:hover { background: rgba(255, 255, 255, .16); }
.facts .copy { position: static; border-color: var(--line); background: var(--surface-2); color: var(--text-2); }

/* Endpoint index and cards */
.endpoint-index { display: grid; gap: 4px; margin: 18px 0 28px; }
.endpoint-index .grp { margin: 12px 0 2px; font-weight: 700; font-size: 14px; }
.endpoint-index a { display: flex; align-items: center; gap: 12px; padding: 6px 10px; border-radius: 8px; color: var(--text); text-decoration: none; font-size: 14.5px; }
.endpoint-index a:hover { background: var(--surface); }
.endpoint-index .p { font-family: ui-monospace, monospace; font-size: 13.5px; }
.endpoint-index .t { color: var(--muted); margin-left: auto; text-align: right; }
.ep { background: var(--surface); border: 1px solid var(--line); border-radius: 16px; box-shadow: var(--shadow); margin: 0 0 26px; overflow: hidden; scroll-margin-top: 76px; }
.ep-head { padding: 18px 22px 14px; border-bottom: 1px solid var(--line); }
.ep-line { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; }
.ep-line .path { font: 600 16px ui-monospace, monospace; word-break: break-all; }
.ep-head h3 { margin: 8px 0 4px; font-size: 19px; }
.ep-head p { margin: 0; color: var(--text-2); }
.badge { font-size: 11.5px; font-weight: 600; padding: 2px 9px; border-radius: 99px; background: var(--surface-2); color: var(--text-2); white-space: nowrap; }
.badge.lock { background: var(--warn-bg); color: var(--put); }
.badge.open { background: var(--safe-bg); color: var(--ok); }
.ep-body { padding: 16px 22px 22px; display: grid; gap: 16px; }
.ep-body h4 { margin: 4px 0 6px; font-size: 13px; text-transform: uppercase; letter-spacing: .05em; color: var(--muted); }
.params { width: 100%; border-collapse: collapse; font-size: 14px; }
.params td { padding: 7px 10px 7px 0; border-bottom: 1px solid var(--line); vertical-align: top; }
.params tr:last-child td { border-bottom: 0; }
.params td:first-child { font: 600 13.5px ui-monospace, monospace; white-space: nowrap; width: 1%; padding-right: 16px; }
.params .type { color: var(--muted); font-size: 12.5px; white-space: nowrap; width: 1%; padding-right: 16px; }
.req { font-size: 11px; font-weight: 700; color: var(--bad); margin-left: 6px; text-transform: uppercase; }
.opt { font-size: 11px; color: var(--muted); margin-left: 6px; }
.tabs { display: flex; gap: 4px; margin-bottom: 8px; }
.tabs button { font: 600 13px system-ui; padding: 6px 12px; border-radius: 8px; border: 1px solid var(--line); background: var(--surface-2); color: var(--text-2); cursor: pointer; }
.tabs button.on { background: var(--code-bg); color: #fff; border-color: var(--code-bg); }
.status-pill { display: inline-block; font: 700 12.5px ui-monospace, monospace; padding: 2px 9px; border-radius: 6px; }
.status-pill.s2 { color: var(--ok); background: var(--get-bg); } .status-pill.s4 { color: var(--put); background: var(--put-bg); } .status-pill.s5 { color: var(--bad); background: var(--delete-bg); }
.errors-list { margin: 0; padding: 0; list-style: none; display: grid; gap: 6px; font-size: 14px; }
.errors-list li { display: flex; gap: 10px; align-items: baseline; }
.hidden-note { font-size: 12.5px; color: var(--muted); margin-top: 6px; }

/* Try it */
details.try { border: 1px solid var(--line); border-radius: 12px; background: var(--surface-2); }
details.try > summary { cursor: pointer; padding: 11px 14px; font-weight: 700; color: var(--accent); list-style: none; display: flex; align-items: center; gap: 8px; }
details.try > summary::-webkit-details-marker { display: none; }
details.try > summary::before { content: "▶"; font-size: 10px; transition: transform .15s; }
details.try[open] > summary::before { transform: rotate(90deg); }
.try-body { padding: 4px 14px 16px; display: grid; gap: 12px; }
.try-grid { display: grid; grid-template-columns: max-content 1fr; gap: 8px 12px; align-items: center; font-size: 14px; }
.try-grid label { font: 600 13px ui-monospace, monospace; }
.try-grid input, .try-body textarea { font: 13px ui-monospace, monospace; padding: 7px 9px; border: 1px solid var(--line); border-radius: 8px; background: var(--surface); color: var(--text); width: 100%; min-width: 0; }
.try-body textarea { min-height: 150px; resize: vertical; }
.try-actions { display: flex; gap: 10px; align-items: center; flex-wrap: wrap; }
.btn { font: 600 14px system-ui; padding: 8px 16px; border-radius: 9px; border: 1px solid var(--accent); background: var(--accent); color: #fff; cursor: pointer; }
.btn:disabled { opacity: .5; cursor: wait; }
.btn.small { padding: 6px 10px; font-size: 12.5px; background: var(--surface); color: var(--text-2); border-color: var(--line); }
.try-warn { font-size: 13px; color: var(--put); }
.try-result { display: grid; gap: 10px; }
.toast { position: fixed; bottom: 20px; left: 50%; transform: translateX(-50%); background: var(--text); color: var(--page); padding: 9px 16px; border-radius: 10px; font-size: 14px; z-index: 50; }

@media (max-width: 960px) {
  .layout { grid-template-columns: 1fr; }
  .menu-btn { display: block; }
  .toc { position: fixed; top: 59px; left: 0; bottom: 0; width: min(300px, 85vw); height: auto; z-index: 15; background: var(--surface); transform: translateX(-100%); transition: transform .2s; box-shadow: 0 0 40px rgba(0, 0, 0, .2); }
  .toc.open { transform: none; }
  .two { grid-template-columns: 1fr; }
  .token-box label { display: none; }
  .token-box input { width: 100%; max-width: none; }
}
@media (max-width: 600px) {
  body { font-size: 15px; }
  .topbar { gap: 10px; padding: 10px 14px; }
  .brand span:last-child { display: none; }
  .content { padding: 18px 16px 60px; }
  .ep-head, .ep-body { padding-left: 16px; padding-right: 16px; }
  .endpoint-index .t { display: none; }
  .glossary { grid-template-columns: 1fr; gap: 2px; }
  .glossary dd { margin-bottom: 10px; }
  .try-grid { grid-template-columns: 1fr; gap: 4px; }
  .temp-compare { grid-template-columns: 1fr; }
  .token-box #tokenShow { display: none; }
  /* Parameter tables: name and type on one line, the description underneath. */
  .params tr { display: grid; grid-template-columns: auto 1fr; column-gap: 10px; padding: 8px 0; border-bottom: 1px solid var(--line); }
  .params tr:last-child { border-bottom: 0; }
  .params td { border: 0; padding: 0; width: auto !important; }
  .params td:last-child { grid-column: 1 / -1; margin-top: 2px; }
}