/* SkyDOS White Paper — one stylesheet for every language. Light/dark by system preference, print-friendly. */
:root {
  --bg: #fbfaf7;
  --surface: #ffffff;
  --ink: #16181d;
  --muted: #5b6270;
  --line: #e4e1da;
  --accent: #0e6b8c;
  --accent-soft: #e3f1f6;
  --gold: #a67c1a;
  --live: #1f7a4d;
  --build: #9a5b00;
  --plan: #5b6270;
  --radius: 10px;
  --measure: 46rem;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0e1013;
    --surface: #161a1f;
    --ink: #e8e6e1;
    --muted: #9aa1ad;
    --line: #2a2f37;
    --accent: #5cc3e6;
    --accent-soft: #13303b;
    --gold: #d9b45a;
    --live: #5fd39a;
    --build: #f0b45c;
    --plan: #9aa1ad;
  }
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 17px/1.65 "Inter", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  -webkit-text-size-adjust: 100%;
}
a { color: var(--accent); }
img { max-width: 100%; height: auto; }

.top {
  position: sticky; top: 0; z-index: 5;
  display: flex; align-items: center; justify-content: space-between; gap: 1rem;
  padding: .6rem 16px;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
}
.top img { height: 34px; width: auto; display: block; }
/* The brand logo is drawn for dark backgrounds: give it a dark plate on light pages. */
.top img, .cover .logo { background: #0b0c0e; border-radius: 8px; padding: 6px 10px; }
@media (prefers-color-scheme: dark) { .top img, .cover .logo { background: none; padding: 0; } }
.top nav { display: flex; gap: .9rem; font-size: .9rem; }
.top nav a { text-decoration: none; color: var(--muted); white-space: nowrap; }
.top nav a[aria-current="true"] { color: var(--ink); font-weight: 600; }

.wrap { display: grid; grid-template-columns: 15rem minmax(0, var(--measure)); gap: 3rem; max-width: 66rem; margin: 0 auto; padding: 0 16px; }
.toc { position: sticky; top: 4rem; align-self: start; max-height: calc(100vh - 5rem); overflow: auto; padding: 2rem 0; font-size: .88rem; }
.toc ol { list-style: none; padding: 0; margin: 0; counter-reset: s; }
.toc li { margin: .3rem 0; }
.toc a { color: var(--muted); text-decoration: none; }
.toc a:hover { color: var(--ink); }
main { padding: 2rem 0 5rem; min-width: 0; }

.cover { padding: 3rem 0 2rem; border-bottom: 1px solid var(--line); margin-bottom: 2rem; }
.cover .logo { width: 220px; height: auto; }
.cover h1 { font-size: clamp(2rem, 5vw, 3rem); line-height: 1.12; margin: 1.2rem 0 .6rem; letter-spacing: -.01em; }
.cover .tag { font-size: 1.2rem; color: var(--muted); margin: 0 0 1.4rem; }
.cover .meta { font-size: .88rem; color: var(--muted); }
.cover figure { margin: 1.6rem 0 0; }
.cover figure img { border-radius: var(--radius); border: 1px solid var(--line); }

h2 { font-size: 1.6rem; line-height: 1.25; margin: 3.2rem 0 .8rem; padding-top: .4rem; scroll-margin-top: 4.5rem; }
h3 { font-size: 1.15rem; margin: 2rem 0 .5rem; scroll-margin-top: 4.5rem; }
h2 .n { color: var(--accent); margin-right: .4rem; font-variant-numeric: tabular-nums; }
p, ul, ol { margin: 0 0 1rem; }
li { margin: .25rem 0; }
blockquote { margin: 1.2rem 0; padding: .8rem 1.1rem; border-left: 3px solid var(--gold); background: var(--surface); border-radius: 0 var(--radius) var(--radius) 0; }
blockquote p { margin: .3rem 0; }
.lead { font-size: 1.12rem; }
.box { background: var(--accent-soft); border-radius: var(--radius); padding: 1rem 1.2rem; margin: 1.2rem 0; }
.box h3 { margin-top: 0; }
.note { font-size: .9rem; color: var(--muted); }

.table { overflow-x: auto; margin: 1rem 0 1.4rem; border: 1px solid var(--line); border-radius: var(--radius); background: var(--surface); }
table { border-collapse: collapse; width: 100%; font-size: .93rem; }
th, td { text-align: left; vertical-align: top; padding: .55rem .75rem; border-bottom: 1px solid var(--line); }
th { font-weight: 600; background: color-mix(in srgb, var(--surface) 70%, var(--line)); }
tr:last-child td { border-bottom: 0; }
td.code { font-variant-numeric: tabular-nums; white-space: nowrap; color: var(--muted); }

.st { display: inline-block; font-size: .78rem; font-weight: 600; padding: .05rem .5rem; border-radius: 999px; border: 1px solid currentColor; white-space: nowrap; }
.st.live { color: var(--live); }
.st.build { color: var(--build); }
.st.plan { color: var(--plan); }

.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(13rem, 1fr)); gap: .9rem; margin: 1rem 0 1.4rem; }
.card { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: .9rem 1rem; }
.card h4 { margin: 0 0 .3rem; font-size: 1rem; }
.card p { margin: 0; font-size: .92rem; color: var(--muted); }
.stat { font-size: 1.6rem; font-weight: 700; color: var(--ink); display: block; line-height: 1.2; }

footer { border-top: 1px solid var(--line); margin-top: 4rem; padding-top: 1.2rem; font-size: .85rem; color: var(--muted); }

@media (max-width: 900px) {
  .wrap { grid-template-columns: minmax(0, 1fr); gap: 0; }
  .toc { position: static; max-height: none; padding: 1rem 0 0; border-bottom: 1px solid var(--line); }
  .toc ol { columns: 2; column-gap: 1.2rem; }
  body { font-size: 16px; }
}
@media (max-width: 520px) { .toc ol { columns: 1; } .top nav { gap: .6rem; font-size: .82rem; } .top nav a:last-child { display: none; } }

@media print {
  :root { --bg: #fff; --surface: #fff; --ink: #000; --muted: #444; --line: #ccc; --accent: #0e6b8c; --accent-soft: #f2f7f9; }
  .top, .toc { display: none; }
  .wrap { display: block; max-width: none; padding: 0; }
  body { font-size: 11pt; }
  h2 { break-after: avoid; }
  .table, .card, blockquote, .box { break-inside: avoid; }
  a { color: inherit; text-decoration: none; }
}