/* qctf notes — one stylesheet, no build step, no external requests. */

:root {
  --bg: #ffffff;
  --fg: #1a1c1e;
  --muted: #5b6169;
  --rule: #dfe3e8;
  --accent: #0b5fa5;
  --code-bg: #f4f6f8;
  --mark: #fff3c4;
  --warn-bg: #fff8e6;
  --warn-edge: #d9a300;
  --ok-bg: #eaf7ee;
  --ok-edge: #2e8b46;
  --mono: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #14171a;
    --fg: #e6e8ea;
    --muted: #9aa2ab;
    --rule: #2b3138;
    --accent: #63b3ed;
    --code-bg: #1c2126;
    --mark: #4a3d12;
    --warn-bg: #2a2413;
    --warn-edge: #b08900;
    --ok-bg: #16271c;
    --ok-edge: #4caf6a;
  }
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font: 16px/1.6 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

/* ---- nav ---- */
nav.top {
  position: sticky;
  top: 0;
  z-index: 10;
  background: var(--bg);
  border-bottom: 1px solid var(--rule);
  padding: 0.5rem 1rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem 0.9rem;
  align-items: baseline;
}
nav.top .brand {
  font-weight: 700;
  margin-right: 0.4rem;
  color: var(--fg);
  text-decoration: none;
  white-space: nowrap;
}
nav.top a {
  color: var(--muted);
  text-decoration: none;
  font-size: 0.9rem;
  white-space: nowrap;
}
nav.top a:hover { color: var(--accent); }
nav.top a[aria-current="page"] { color: var(--accent); font-weight: 600; }

/* ---- layout ---- */
main {
  max-width: 46rem;
  margin: 0 auto;
  padding: 1.25rem 1rem 5rem;
}

h1 { font-size: 1.7rem; line-height: 1.25; margin: 0.6rem 0 0.3rem; }
h2 {
  font-size: 1.25rem;
  margin: 2.2rem 0 0.6rem;
  padding-top: 0.5rem;
  border-top: 1px solid var(--rule);
}
h3 { font-size: 1.02rem; margin: 1.4rem 0 0.4rem; }
h2:first-of-type { border-top: none; }

p, li { overflow-wrap: break-word; }
.lede { color: var(--muted); font-size: 1.02rem; }

a { color: var(--accent); }

/* ---- table of contents ---- */
.toc {
  border: 1px solid var(--rule);
  border-radius: 6px;
  padding: 0.7rem 1rem;
  margin: 1.2rem 0;
  background: var(--code-bg);
}
.toc strong { font-size: 0.8rem; text-transform: uppercase; letter-spacing: 0.04em; color: var(--muted); }
.toc ol { margin: 0.4rem 0 0; padding-left: 1.2rem; }
.toc li { margin: 0.15rem 0; }

/* ---- code ---- */
code {
  font-family: var(--mono);
  font-size: 0.88em;
  background: var(--code-bg);
  padding: 0.12em 0.34em;
  border-radius: 3px;
}
pre {
  background: var(--code-bg);
  border: 1px solid var(--rule);
  border-radius: 6px;
  padding: 0.8rem;
  overflow-x: auto;
  font-size: 0.85rem;
  line-height: 1.5;
}
pre code { background: none; padding: 0; font-size: inherit; }

/* ---- tables: scroll rather than squash the page ---- */
.tw { overflow-x: auto; margin: 1rem 0; -webkit-overflow-scrolling: touch; }
table { border-collapse: collapse; width: 100%; font-size: 0.9rem; }
th, td {
  border: 1px solid var(--rule);
  padding: 0.4rem 0.6rem;
  text-align: left;
  vertical-align: top;
}
th { background: var(--code-bg); font-weight: 600; white-space: nowrap; }
td code { white-space: nowrap; }

/* ---- callouts ---- */
.note, .warn, .win {
  border-left: 3px solid var(--accent);
  background: var(--code-bg);
  padding: 0.6rem 0.9rem;
  margin: 1rem 0;
  border-radius: 0 4px 4px 0;
}
.warn { border-left-color: var(--warn-edge); background: var(--warn-bg); }
.win { border-left-color: var(--ok-edge); background: var(--ok-bg); }
.note p:first-child, .warn p:first-child, .win p:first-child { margin-top: 0; }
.note p:last-child, .warn p:last-child, .win p:last-child { margin-bottom: 0; }

/* ---- misc ---- */
.cards { display: grid; gap: 0.75rem; grid-template-columns: repeat(auto-fit, minmax(15rem, 1fr)); margin: 1.2rem 0; }
.card { border: 1px solid var(--rule); border-radius: 6px; padding: 0.8rem 1rem; }
.card h3 { margin-top: 0; }
.card p { margin-bottom: 0; color: var(--muted); font-size: 0.92rem; }

kbd {
  font-family: var(--mono);
  font-size: 0.82em;
  border: 1px solid var(--rule);
  border-bottom-width: 2px;
  border-radius: 4px;
  padding: 0.05em 0.35em;
}

.mono { font-family: var(--mono); }
mark { background: var(--mark); color: inherit; padding: 0 0.15em; }

footer {
  border-top: 1px solid var(--rule);
  margin-top: 3rem;
  padding-top: 1rem;
  color: var(--muted);
  font-size: 0.85rem;
}

@media (max-width: 480px) {
  main { padding: 1rem 0.85rem 4rem; }
  h1 { font-size: 1.45rem; }
  nav.top { gap: 0.2rem 0.7rem; padding: 0.45rem 0.85rem; }
}