/* Shared styles for p4-web docs subpages (changes.html, guide.html).
   Same design system as the landing page (index.html keeps its own inline
   copy so it stays a single self-contained file). */

:root {
  --bg: #F7F8F5;
  --panel: #FFFFFF;
  --panel-deep: #10151B;
  --panel-deep-ink: #D7DEE6;
  --ink: #1C2128;
  --muted: #5B6572;
  --faint: #8A948E;
  --line: #DDE3DC;
  --accent: #256E45;
  --accent-ink: #FFFFFF;
  --chip-bg: #EDF1EC;
  --shadow: 0 1px 2px rgba(28,33,40,.06), 0 8px 24px rgba(28,33,40,.05);
  --mono: "SF Mono", "Cascadia Code", "JetBrains Mono", Menlo, Consolas, "Liberation Mono", monospace;
  --sans: system-ui, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #12161B;
    --panel: #181E25;
    --panel-deep: #0C1015;
    --panel-deep-ink: #C9D2DB;
    --ink: #E6EAEE;
    --muted: #9AA6B2;
    --faint: #6C7883;
    --line: #29323C;
    --accent: #52B383;
    --accent-ink: #0C1512;
    --chip-bg: #1F2831;
    --shadow: 0 1px 2px rgba(0,0,0,.4), 0 8px 24px rgba(0,0,0,.35);
  }
}
:root[data-theme="light"] {
  --bg: #F7F8F5;
  --panel: #FFFFFF;
  --panel-deep: #10151B;
  --panel-deep-ink: #D7DEE6;
  --ink: #1C2128;
  --muted: #5B6572;
  --faint: #8A948E;
  --line: #DDE3DC;
  --accent: #256E45;
  --accent-ink: #FFFFFF;
  --chip-bg: #EDF1EC;
  --shadow: 0 1px 2px rgba(28,33,40,.06), 0 8px 24px rgba(28,33,40,.05);
}
:root[data-theme="dark"] {
  --bg: #12161B;
  --panel: #181E25;
  --panel-deep: #0C1015;
  --panel-deep-ink: #C9D2DB;
  --ink: #E6EAEE;
  --muted: #9AA6B2;
  --faint: #6C7883;
  --line: #29323C;
  --accent: #52B383;
  --accent-ink: #0C1512;
  --chip-bg: #1F2831;
  --shadow: 0 1px 2px rgba(0,0,0,.4), 0 8px 24px rgba(0,0,0,.35);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { transition: none !important; animation: none !important; }
}
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--accent); text-decoration-thickness: 1px; text-underline-offset: 3px; }
a:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: 2px; }
code, pre, .mono { font-family: var(--mono); }

.page { max-width: 980px; margin: 0 auto; padding: 0 24px 96px; }

/* ---- site nav ---- */
.sitenav {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 16px;
  padding: 22px 0 0;
  font-family: var(--mono);
  font-size: 14px;
}
.sitenav .brand { font-weight: 700; color: var(--ink); text-decoration: none; }
.sitenav-links { display: flex; gap: 18px; flex-wrap: wrap; }
.sitenav-links a { color: var(--muted); text-decoration: none; }
.sitenav-links a:hover { color: var(--accent); }
.sitenav-links a[aria-current="page"] { color: var(--accent); font-weight: 600; }

/* ---- page head ---- */
.doc-head { padding-top: 56px; }
.doc-head h1 {
  font-family: var(--mono);
  font-weight: 700;
  font-size: clamp(28px, 4.6vw, 40px);
  line-height: 1.15;
  letter-spacing: -0.03em;
  margin: 0 0 12px;
  text-wrap: balance;
}
.doc-head .lede { font-size: 17px; color: var(--muted); max-width: 62ch; margin: 0; }
.doc-head .lede code { background: var(--chip-bg); padding: 1px 6px; border-radius: 4px; font-size: 0.87em; }

/* ---- section scaffold: gutter + content, like a file view ---- */
section.cl {
  display: grid;
  grid-template-columns: 118px 1fr;
  gap: 28px;
  margin-top: 72px;
}
.gutter {
  border-right: 2px solid var(--line);
  padding-right: 18px;
  text-align: right;
}
.gutter .clno {
  font-family: var(--mono);
  font-size: 13px;
  color: var(--accent);
  font-weight: 600;
  white-space: nowrap;
}
.gutter .clmeta {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--faint);
  margin-top: 2px;
  white-space: nowrap;
}
.content { min-width: 0; }
h2 {
  font-family: var(--mono);
  font-size: 22px;
  line-height: 1.3;
  letter-spacing: -0.02em;
  margin: 0 0 6px;
  text-wrap: balance;
}
.kicker { color: var(--muted); max-width: 64ch; margin: 0 0 20px; }
.content p { max-width: 64ch; }
.content p code, .kicker code, .chg-title code {
  background: var(--chip-bg);
  padding: 1px 6px;
  border-radius: 4px;
  font-size: 0.87em;
}
@media (max-width: 720px) {
  section.cl { grid-template-columns: 1fr; gap: 10px; margin-top: 56px; }
  .gutter {
    border-right: 0;
    border-bottom: 2px solid var(--line);
    padding: 0 0 8px;
    text-align: left;
    display: flex;
    gap: 12px;
    align-items: baseline;
  }
  .gutter .clmeta { margin-top: 0; }
}

/* ---- changelog rows ---- */
ul.chg-list { list-style: none; margin: 0; padding: 0; }
ul.chg-list li {
  display: flex;
  gap: 14px;
  align-items: baseline;
  padding: 8px 0;
  border-bottom: 1px solid var(--line);
}
ul.chg-list li:last-child { border-bottom: 0; }
.chg-cl {
  font-family: var(--mono);
  font-size: 13px;
  font-weight: 600;
  color: var(--accent);
  flex: 0 0 3.4em;
  text-align: right;
  font-variant-numeric: tabular-nums;
}
.chg-title { font-size: 15px; }
.chg-note { color: var(--muted); }

/* ---- guide figures ---- */
figure.shot {
  margin: 18px 0 0;
  border: 1px solid var(--line);
  border-radius: 10px;
  overflow: hidden;
  box-shadow: var(--shadow);
  background: var(--panel);
}
figure.shot img { display: block; width: 100%; height: auto; }
figure.shot figcaption {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--muted);
  padding: 9px 14px;
  border-top: 1px solid var(--line);
}
.demo-note {
  font-family: var(--mono);
  font-size: 13px;
  color: var(--muted);
  background: var(--chip-bg);
  border-radius: 6px;
  padding: 10px 14px;
  margin: 22px 0 0;
  max-width: 64ch;
}

/* ---- steps list inside guide sections ---- */
ul.steps { list-style: none; margin: 0; padding: 0; max-width: 64ch; }
ul.steps li { padding-left: 22px; position: relative; margin-bottom: 8px; font-size: 15px; }
ul.steps li::before {
  content: "▸";
  position: absolute; left: 2px; top: 0;
  color: var(--accent);
  font-size: 13px;
}

/* ---- footer ---- */
footer {
  margin-top: 96px;
  border-top: 2px solid var(--line);
  padding-top: 26px;
  display: flex;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
  font-family: var(--mono);
  font-size: 13px;
  color: var(--muted);
}