/* Site-wide dark theme: header, footer and the plain page (404). */

:root {
  color-scheme: dark;
  --bar-h: 76px;
  --bg: #07090a;
  --bg-raised: #0d1110;
  --surface: rgba(255, 255, 255, 0.04);
  --surface-strong: rgba(255, 255, 255, 0.07);
  --rule: rgba(255, 255, 255, 0.09);
  --text: #eef2ef;
  --muted: #97a39b;
  --faint: #5f6b64;
  --green: #5be49b;
  --green-deep: #2d5f3f;
  --gold: #f2c14e;
  --gold-deep: #e8b23a;
  --link: #8fe3b4;
  --radius: 18px;
  --font: -apple-system, BlinkMacSystemFont, "SF Pro Text", "PingFang TC", "Noto Sans TC",
    "Segoe UI", "Helvetica Neue", Arial, sans-serif;
  --font-display: -apple-system, BlinkMacSystemFont, "SF Pro Display", "PingFang TC",
    "Noto Sans TC", "Segoe UI", "Helvetica Neue", Arial, sans-serif;
}

* { box-sizing: border-box; }

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

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 17px/1.7 var(--font);
  -webkit-font-smoothing: antialiased;
}

a { color: var(--link); text-underline-offset: 3px; }

img { max-width: 100%; }

/* Header */

.bar {
  position: sticky;
  top: 12px;
  z-index: 20;
  width: min(1160px, 100% - 24px);
  margin: 12px auto 0;
  border: 1px solid var(--rule);
  border-radius: 14px;
  background: rgba(13, 17, 16, 0.72);
  backdrop-filter: saturate(160%) blur(18px);
  -webkit-backdrop-filter: saturate(160%) blur(18px);
}

.bar-inner {
  display: flex;
  align-items: center;
  gap: 20px;
  min-height: 56px;
  padding: 0 10px 0 16px;
}

.page, footer .footer-inner {
  max-width: 1160px;
  margin: 0 auto;
  padding-left: 24px;
  padding-right: 24px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-right: auto;
  color: var(--text);
  font-weight: 700;
  letter-spacing: 0.01em;
  text-decoration: none;
}

.brand img { width: 30px; height: 30px; border-radius: 8px; }

.bar nav { display: flex; align-items: center; gap: 20px; font-size: 15px; }
.bar nav a { color: var(--muted); text-decoration: none; transition: color 0.2s; }
.bar nav a:hover, .bar nav a[aria-current="page"] { color: var(--text); }

.bar nav .bar-cta {
  padding: 6px 14px;
  border-radius: 8px;
  background: var(--gold);
  color: #07090a;
  font-weight: 600;
  white-space: nowrap;
}
.bar nav .bar-cta:hover { background: var(--gold-deep); color: #07090a; }

/* Language menu */

.lang-menu { position: relative; }

.lang-menu summary {
  display: flex;
  align-items: center;
  gap: 5px;
  color: var(--muted);
  list-style: none;
  cursor: pointer;
  user-select: none;
  transition: color 0.2s;
}
.lang-menu summary::-webkit-details-marker { display: none; }
.lang-menu summary:hover, .lang-menu[open] summary { color: var(--text); }
.lang-menu summary::after {
  content: "";
  width: 6px;
  height: 6px;
  margin-top: -3px;
  border-right: 1.5px solid currentColor;
  border-bottom: 1.5px solid currentColor;
  transform: rotate(45deg);
  transition: transform 0.2s, margin 0.2s;
}
.lang-menu[open] summary::after { margin-top: 3px; transform: rotate(-135deg); }

.lang-menu-list {
  position: absolute;
  top: calc(100% + 14px);
  right: 0;
  min-width: 150px;
  padding: 6px;
  border: 1px solid var(--rule);
  border-radius: 12px;
  background: #101513;
  box-shadow: 0 20px 50px -16px rgba(0, 0, 0, 0.9);
}
.bar nav .lang-menu-list a {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  padding: 7px 10px;
  border-radius: 8px;
  white-space: nowrap;
}
.bar nav .lang-menu-list a:hover { background: var(--surface-strong); }
.bar nav .lang-menu-list a[aria-current="true"] { color: var(--text); }
.lang-menu-list a[aria-current="true"]::after { content: "✓"; color: var(--green); font-weight: 700; }

@media (max-width: 960px) {
  .bar-wide { display: none; }
}

@media (max-width: 640px) {
  .bar nav .bar-cta { display: none; }
}

/* Plain page */

main.page {
  max-width: 760px;
  padding-top: 56px;
  padding-bottom: 72px;
}

h1, h2, h3 { font-family: var(--font-display); letter-spacing: -0.015em; }
main.page h1 { font-size: 40px; line-height: 1.2; margin: 0 0 8px; }
main.page h2 { font-size: 23px; line-height: 1.35; margin: 48px 0 10px; }
main.page h3 { font-size: 18px; margin: 28px 0 6px; }
main.page p, main.page li { color: #d6ddd8; }

ul { padding-left: 1.3em; }
li + li { margin-top: 4px; }

/* Footer */

footer {
  border-top: 1px solid var(--rule);
  color: var(--faint);
  font-size: 14px;
}

footer .footer-inner {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 20px;
  padding-top: 24px;
  padding-bottom: 40px;
}

footer .footer-inner span { margin-right: auto; }
footer a { color: var(--muted); text-decoration: none; }
footer a:hover { color: var(--text); }

@media (max-width: 560px) {
  body { font-size: 16px; }
  .page, footer .footer-inner { padding-left: 16px; padding-right: 16px; }
  .bar nav { gap: 14px; }
  main.page h1 { font-size: 30px; }
}

@media (max-width: 440px) {
  .brand span { display: none; }
  .bar nav { gap: 12px; font-size: 14px; }
}

@media (max-width: 360px) {
  .bar-inner { gap: 10px; padding: 0 10px; }
  .bar nav { gap: 9px; font-size: 13px; }
}

/* Chinese headings and labels break at punctuation and spaces, not between any
   two characters, so they never split mid-phrase; headings balance their lines. */
:lang(zh-Hant) {
  word-break: keep-all;
  overflow-wrap: anywhere;
  line-break: strict;
}
:lang(zh-Hant) :is(h1, h2, h3) { text-wrap: balance; }
/* Running text flows as Chinese normally does. Held to punctuation and spaces,
   a line could only end at the space beside a Latin word such as App, and would
   stop short there whenever the next phrase didn't fit. */
:lang(zh-Hant) :is(p, li) { text-wrap: pretty; }
:lang(zh-Hant) :is(p, li), :lang(zh-Hant) :is(p, li) * { word-break: normal; }

.nowrap { white-space: nowrap; }