/* Shared styling for the PhimDan site. Matches the app (specs/design.md): ivory ground, lacquer ink,
   copper (đồng) links, gold-leaf (kim) hairlines; SF Pro Rounded titles via the system font stack.
   No web fonts and no third-party requests. Light + dark via prefers-color-scheme. */

:root {
  --ground: #FBF8F3;
  --surface: #FFFFFF;
  --ink: #231A14;
  --muted: #6E6258;
  --dong: #9A5A2E;
  --kim: #C9A24B;
  --kim-text: #8A6A1F;
  --line: #ECE3D6;
  --callout: #231A14;
  --callout-ink: #F3EBDD;
  --callout-accent: #E3C27A;
  --shadow: 0 12px 30px rgba(35, 26, 20, 0.08);
  --max: 760px;
}
@media (prefers-color-scheme: dark) {
  :root {
    --ground: #14100D;
    --surface: #1F1915;
    --ink: #F3EBDD;
    --muted: #BBAE9C;
    --dong: #E0A274;
    --kim: #E3C27A;
    --kim-text: #E3C27A;
    --line: #2E2620;
    --callout: #1F1915;
    --shadow: 0 12px 30px rgba(0, 0, 0, 0.35);
  }
}

* { box-sizing: border-box; }
html, body { overflow-x: hidden; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  background: var(--ground);
  color: var(--ink);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}
.rounded, h1, h2, .brand { font-family: ui-rounded, "SF Pro Rounded", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; }

a { color: var(--dong); text-decoration: none; }
a:hover { text-decoration: underline; }
:focus-visible { outline: 2px solid var(--dong); outline-offset: 3px; border-radius: 4px; }
.wrap { max-width: var(--max); margin: 0 auto; padding: 0 16px; }
@media (min-width: 620px) { .wrap { padding: 0 24px; } }

header {
  position: sticky; top: 0; z-index: 20;
  border-bottom: 1px solid var(--line);
  background: color-mix(in srgb, var(--ground) 88%, transparent);
  backdrop-filter: saturate(150%) blur(12px);
}
.nav { display: flex; align-items: center; justify-content: space-between; height: 64px; gap: 12px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 800; font-size: 19px; color: var(--ink); }
.brand:hover { text-decoration: none; }
.brand img { width: 34px; height: 34px; border-radius: 8px; }
.brand .dan { color: var(--dong); }
.lang { font-size: 14px; color: var(--muted); white-space: nowrap; }
.lang a { color: var(--muted); }
.lang a:hover { color: var(--ink); }

main { padding: 48px 0 72px; }
.eyebrow { font-size: 12.5px; letter-spacing: 0.14em; text-transform: uppercase; color: var(--kim-text); font-weight: 600; display: inline-flex; align-items: center; gap: 10px; margin-bottom: 14px; }
.eyebrow::before { content: ""; width: 26px; height: 1px; background: var(--kim); }
h1 { font-weight: 800; font-size: clamp(32px, 6vw, 48px); line-height: 1.08; letter-spacing: -0.02em; margin: 0 0 8px; }
.updated { color: var(--muted); font-size: 14px; margin: 0 0 32px; }
h2 { font-weight: 700; font-size: 22px; margin: 36px 0 8px; padding-top: 12px; border-top: 1px solid var(--line); }
section > h2:first-of-type { border-top: none; padding-top: 0; }
p, li { font-size: 16px; }
.muted { color: var(--muted); }
ul, ol { padding-left: 22px; }
li { margin: 7px 0; }
.callout {
  background: var(--callout); color: var(--callout-ink); border-left: 3px solid var(--callout-accent);
  border-radius: 12px; padding: 18px 20px; margin: 22px 0; box-shadow: var(--shadow);
}
.callout p, .callout strong { color: var(--callout-ink); margin: 0; }
.callout strong { color: var(--callout-accent); }
.callout a { color: var(--callout-accent); }
hr { border: none; border-top: 1px solid var(--line); margin: 48px 0; }
section[lang="en"] { scroll-margin-top: 80px; }

.hero { text-align: center; padding: 24px 0 8px; }
.hero img { width: 112px; height: 112px; border-radius: 26px; box-shadow: var(--shadow); }
.hero h1 { margin-top: 20px; }
.hero p { max-width: 560px; margin: 8px auto; color: var(--muted); font-size: 18px; }
.cards { display: grid; gap: 14px; margin: 36px 0; }
@media (min-width: 620px) { .cards { grid-template-columns: repeat(3, 1fr); } }
.card { background: var(--surface); border: 1px solid var(--line); border-radius: 14px; padding: 16px 18px; }
.card strong { display: block; margin-bottom: 4px; }
.card p { margin: 0; color: var(--muted); font-size: 15px; }

footer { border-top: 1px solid var(--line); padding: 28px 0 56px; color: var(--muted); }
.foot { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 12px; font-size: 14px; align-items: center; }
.foot nav { display: flex; flex-wrap: wrap; gap: 8px 18px; }
.foot nav a { color: var(--muted); }
.foot nav a:hover { color: var(--ink); }