/* Layout: banda de marca azul noche con el logo; debajo, índice fijo + lectura a ~70ch; código siempre sobre azul noche */
:root {
  --night: #060f1d;           /* fondo de la marca */
  --night-2: #0c1a2f;
  --brand-blue: #85a5d7;      /* "SYSTEMS" del logo */
  --brand-mist: #a5b7cf;
  --bg: #f4f7fb;
  --surface: #ffffff;
  --fg: #0b172a;
  --muted: #4f5f78;
  --line: #d8e0ec;
  --accent: #36599a;
  --accent-soft: #e6edf8;
  --code-bg: #08121f;
  --code-fg: #dfe7f3;
  --code-dim: #7d90ad;
  --warn: #8a5a00;
  --warn-soft: #fbf1dc;
  --font-display: "Sora", "Segoe UI", system-ui, sans-serif;
  --font-body: "IBM Plex Sans", "Segoe UI", system-ui, sans-serif;
  --font-mono: "IBM Plex Mono", ui-monospace, "Cascadia Mono", Consolas, monospace;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #060f1d; --surface: #0b1729; --fg: #eef2f8; --muted: #a5b7cf; --line: #1b2b44;
    --accent: #95b3e2; --accent-soft: #13233b; --code-bg: #040b16; --code-fg: #dfe7f3; --code-dim: #6f84a3;
    --warn: #f0c060; --warn-soft: #2a2312; color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #060f1d; --surface: #0b1729; --fg: #eef2f8; --muted: #a5b7cf; --line: #1b2b44;
  --accent: #95b3e2; --accent-soft: #13233b; --code-bg: #040b16; --code-fg: #dfe7f3; --code-dim: #6f84a3;
  --warn: #f0c060; --warn-soft: #2a2312; color-scheme: dark;
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; }
img { max-width: 100%; }
body { background: var(--bg); color: var(--fg); font: 15.5px/1.65 var(--font-body); }
.band {
  background: radial-gradient(120% 140% at 50% 0%, var(--night-2) 0%, var(--night) 60%);
  color: #eef2f8;
  border-bottom: 1px solid #1b2b44;
}
.band-inner {
  max-width: 1180px; margin: 0 auto;
  padding-left: max(16px, env(safe-area-inset-left, 0px));
  padding-right: max(16px, env(safe-area-inset-right, 0px));
  padding-block: 48px 44px;
  display: grid; gap: 22px;
}
.band img { width: min(300px, 70%); height: auto; display: block; }
.eyebrow { font-family: var(--font-body); font-size: 12px; font-weight: 500; letter-spacing: 0.32em; text-transform: uppercase; color: var(--brand-blue); }
h1 { font-family: var(--font-display); font-weight: 600; font-size: clamp(28px, 4.6vw, 42px); line-height: 1.12; letter-spacing: -0.02em; margin: 0; text-wrap: balance; max-width: 22ch; }
.lede { font-size: 17px; color: var(--brand-mist); margin: 0; max-width: 64ch; }
.lede code { background: rgba(133,165,215,0.14); color: #eef2f8; }
.lede strong { color: #eef2f8; }
.meta { display: flex; flex-wrap: wrap; gap: 8px; }
.chip { font-family: var(--font-mono); font-size: 12px; padding: 3px 10px; border: 1px solid #2a3d5c; border-radius: 999px; color: var(--brand-mist); }
.wrap {
  max-width: 1180px; margin: 0 auto;
  padding-left: max(16px, env(safe-area-inset-left, 0px));
  padding-right: max(16px, env(safe-area-inset-right, 0px));
  padding-block: 12px 80px;
  display: grid; grid-template-columns: 220px minmax(0, 1fr); gap: 56px;
}
nav.toc { position: sticky; top: calc(env(safe-area-inset-top, 0px) + 24px); align-self: start; font-size: 13.5px; padding-top: 24px; }
nav.toc .label { display: block; font-size: 11px; font-weight: 500; letter-spacing: 0.3em; text-transform: uppercase; color: var(--muted); margin: 0 0 12px 8px; }
nav.toc ol { list-style: none; margin: 0; padding: 0; display: grid; gap: 2px; counter-reset: s; }
nav.toc a { display: flex; gap: 10px; padding: 5px 8px; border-radius: 6px; color: var(--muted); text-decoration: none; }
nav.toc a::before { counter-increment: s; content: counter(s, decimal-leading-zero); font-family: var(--font-mono); font-size: 11.5px; color: var(--code-dim); padding-top: 2px; }
nav.toc a:hover, nav.toc a:focus-visible { background: var(--accent-soft); color: var(--fg); outline: none; }
main { min-width: 0; max-width: 760px; }
section { padding-top: 36px; scroll-margin-top: 16px; }
h2 { font-family: var(--font-display); font-weight: 600; font-size: 23px; letter-spacing: -0.01em; margin: 0 0 12px; text-wrap: balance; display: flex; align-items: baseline; gap: 12px; flex-wrap: wrap; }
h2 .num { font-family: var(--font-mono); font-size: 13px; color: var(--accent); font-weight: 500; }
h2 code { font-size: 15px; }
h3 { font-size: 16px; margin: 22px 0 8px; }
p, li { max-width: 68ch; }
a { color: var(--accent); }
code { font-family: var(--font-mono); font-size: 0.88em; background: var(--accent-soft); padding: 1px 5px; border-radius: 4px; overflow-wrap: anywhere; }
.code { position: relative; margin: 14px 0; border-radius: 10px; background: var(--code-bg); border: 1px solid #16253c; }
.code .lang { position: absolute; top: 8px; left: 14px; font-family: var(--font-mono); font-size: 11px; color: var(--code-dim); text-transform: uppercase; letter-spacing: 0.12em; }
.code button { position: absolute; top: 6px; right: 8px; font: 500 12px var(--font-body); color: var(--code-fg); background: transparent; border: 1px solid #2a3d5c; border-radius: 6px; padding: 3px 10px; cursor: pointer; }
.code button:hover, .code button:focus-visible { border-color: #85a5d7; color: #ffffff; outline: none; }
pre { margin: 0; padding: 34px 16px 16px; overflow-x: auto; color: var(--code-fg); font: 13px/1.6 var(--font-mono); }
pre code { background: none; padding: 0; font-size: inherit; overflow-wrap: normal; }
.table { overflow-x: auto; margin: 14px 0; border: 1px solid var(--line); border-radius: 10px; background: var(--surface); }
table { border-collapse: collapse; width: 100%; font-size: 14px; }
th, td { text-align: left; padding: 9px 14px; border-bottom: 1px solid var(--line); vertical-align: top; }
th { font-size: 11.5px; text-transform: uppercase; letter-spacing: 0.14em; color: var(--muted); font-weight: 500; }
tr:last-child td { border-bottom: 0; }
td:first-child { white-space: nowrap; }
td.num { font-family: var(--font-mono); font-variant-numeric: tabular-nums; }
.note { margin: 16px 0; padding: 14px 18px; border-radius: 10px; background: var(--warn-soft); color: var(--fg); border: 1px solid color-mix(in srgb, var(--warn) 35%, transparent); }
.note strong { color: var(--warn); }
.note ul { margin: 6px 0 0; padding-left: 20px; }
ul.rules { padding-left: 20px; }
ul.rules li { margin: 4px 0; }
.method { font-family: var(--font-mono); font-size: 12px; font-weight: 500; color: #ffffff; background: #36599a; padding: 2px 7px; border-radius: 4px; }
.verb { font-family: var(--font-mono); font-size: 11px; font-weight: 500; letter-spacing: 0.04em; color: var(--accent); margin-right: 4px; }
footer { margin-top: 48px; padding-top: 18px; border-top: 1px solid var(--line); color: var(--muted); font-size: 13.5px; }
@media (max-width: 860px) {
  .band-inner { padding-block: 32px 28px; }
  .wrap { grid-template-columns: minmax(0, 1fr); gap: 8px; padding-block: 8px 56px; }
  nav.toc { position: static; }
  nav.toc ol { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (prefers-reduced-motion: no-preference) { html { scroll-behavior: smooth; } }