/* =========================================================================
   IChingStyle · shared stylesheet
   used by: legal pages (privacy / terms / support) in zh-Hans / zh-Hant / en
   homepage uses inline styles; this file mirrors the same design system
   ========================================================================= */

:root {
  --paper:        oklch(0.965 0.012 78);
  --paper-2:      oklch(0.935 0.020 75);
  --paper-3:      oklch(0.895 0.028 72);
  --ink:          oklch(0.20 0.018 60);
  --ink-soft:     oklch(0.40 0.020 60);
  --ink-mute:     oklch(0.58 0.020 60);
  --bronze:       oklch(0.50 0.090 55);
  --bronze-deep:  oklch(0.36 0.075 50);
  --bronze-soft:  oklch(0.66 0.075 60);
  --cinnabar:     oklch(0.52 0.165 30);
  --rule:         color-mix(in oklab, var(--ink) 14%, transparent);
  --rule-soft:    color-mix(in oklab, var(--ink) 7%, transparent);

  --max: 1080px;
  --max-narrow: 720px;

  --font-display: "Songti SC", "STSong", "STSongti", "SimSun", "Noto Serif CJK SC", "Source Han Serif SC", serif;
  --font-body: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-mono: ui-monospace, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.7;
  color: var(--ink);
  background: var(--paper);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

.wrap { max-width: var(--max-narrow); margin: 0 auto; padding: 0 32px; }
.wrap--wide { max-width: var(--max); }

/* ───────────── topbar ───────────── */
.topbar {
  position: sticky; top: 0; z-index: 50;
  background: color-mix(in oklab, var(--paper) 92%, transparent);
  backdrop-filter: blur(12px) saturate(120%);
  -webkit-backdrop-filter: blur(12px) saturate(120%);
  border-bottom: 1px solid var(--rule);
}
.topbar .wrap {
  max-width: var(--max);
  display: flex; align-items: center; justify-content: space-between;
  padding-top: 16px; padding-bottom: 16px;
}
.brand {
  display: inline-flex; align-items: center; gap: 12px;
  font-family: var(--font-display);
  font-size: 20px; font-weight: 600; letter-spacing: 0.08em;
  color: var(--ink); text-decoration: none;
}
.brand-mark {
  width: 28px; height: 28px;
  display: block;
  flex: 0 0 auto;
}
.brand-mark img {
  display: block;
  width: 100%;
  height: 100%;
}
.brand-en {
  font-family: var(--font-mono);
  font-size: 11px; font-weight: 500;
  letter-spacing: 0.18em;
  color: var(--ink-mute);
  text-transform: uppercase;
  border-left: 1px solid var(--rule);
  padding-left: 12px;
  margin-left: 4px;
}
nav.links { display: flex; gap: 24px; align-items: center; font-size: 14px; }
nav.links a { color: var(--ink-soft); text-decoration: none; transition: color .2s; }
nav.links a:hover { color: var(--bronze-deep); }
.lang-pick {
  display: inline-flex; gap: 0;
  font-family: var(--font-mono); font-size: 12px;
  border: 1px solid var(--rule);
  border-radius: 4px;
  overflow: hidden;
}
.lang-pick a {
  padding: 6px 10px; color: var(--ink-mute); text-decoration: none;
  border-right: 1px solid var(--rule);
}
.lang-pick a:last-child { border-right: none; }
.lang-pick a.lang-current { background: var(--ink); color: var(--paper); }

/* ───────────── legal article ───────────── */
article.legal { padding: 72px 0 96px; }
.article-head { margin-bottom: 56px; padding-bottom: 32px; border-bottom: 1px solid var(--rule); }
.article-head .eyebrow,
.eyebrow {
  display: inline-flex; align-items: center; gap: 12px;
  font-family: var(--font-mono);
  font-size: 11px; letter-spacing: 0.22em; text-transform: uppercase;
  color: var(--bronze-deep);
  margin-bottom: 18px;
}
.article-head .eyebrow::before,
.eyebrow::before {
  content: ""; width: 24px; height: 1px; background: var(--bronze);
}
article.legal h1 {
  font-family: var(--font-display); font-weight: 700;
  font-size: clamp(36px, 5vw, 52px);
  letter-spacing: 0.06em;
  color: var(--ink);
  line-height: 1.15;
  margin-bottom: 18px;
}
article.legal .meta {
  font-family: var(--font-mono); font-size: 12px; letter-spacing: 0.05em;
  color: var(--ink-mute);
}

article.legal h2 {
  font-family: var(--font-display); font-weight: 700;
  font-size: 24px; letter-spacing: 0.06em;
  color: var(--ink);
  margin-top: 56px; margin-bottom: 18px;
  position: relative; padding-left: 18px;
}
article.legal h2::before {
  content: ""; position: absolute; left: 0; top: 12px;
  width: 8px; height: 8px;
  background: var(--cinnabar);
}
article.legal h3 {
  font-family: var(--font-display); font-weight: 600;
  font-size: 17px; letter-spacing: 0.04em;
  color: var(--ink);
  margin-top: 28px; margin-bottom: 10px;
}
article.legal p {
  font-size: 15.5px; line-height: 1.85; color: var(--ink-soft);
  margin-bottom: 14px;
}
article.legal p strong { color: var(--ink); font-weight: 500; }
article.legal ul, article.legal ol {
  margin-left: 22px; margin-bottom: 18px;
  color: var(--ink-soft); font-size: 15px; line-height: 1.85;
}
article.legal li { margin-bottom: 6px; }
article.legal a {
  color: var(--bronze-deep);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
  text-decoration-color: var(--rule);
  transition: text-decoration-color .2s;
}
article.legal a:hover { text-decoration-color: var(--bronze); }

/* ───────────── contact card ───────────── */
.contact-card {
  margin: 32px 0;
  padding: 28px 32px;
  background: var(--paper-2);
  border: 1px solid var(--rule);
  border-left: 3px solid var(--cinnabar);
  border-radius: 2px;
}
.contact-card h3 {
  margin-top: 0; margin-bottom: 12px;
  font-family: var(--font-display); font-size: 17px; font-weight: 600;
  letter-spacing: 0.06em; color: var(--ink);
}
.contact-card p { font-size: 14.5px; color: var(--ink-soft); margin-bottom: 8px; }
.contact-card p:last-child { margin-bottom: 0; }
.contact-card a { color: var(--bronze-deep); }
.em { font-family: var(--font-mono); font-size: 13.5px; letter-spacing: 0.02em; text-transform: none; }
code { font-family: var(--font-mono); font-size: 13px; background: var(--paper-2); padding: 1px 6px; border-radius: 2px; color: var(--bronze-deep); word-break: break-all; }

/* ───────────── FAQ ───────────── */
.faq dt {
  font-family: var(--font-display); font-weight: 600;
  font-size: 16px; letter-spacing: 0.04em;
  color: var(--ink);
  margin-top: 28px; margin-bottom: 10px;
  position: relative; padding-left: 24px;
}
.faq dt::before {
  content: "问"; position: absolute; left: 0; top: 0;
  width: 18px; height: 18px;
  display: inline-grid; place-items: center;
  font-size: 10px; font-weight: 500;
  color: var(--paper); background: var(--bronze-deep);
  border-radius: 2px; line-height: 1;
}
.faq dd {
  color: var(--ink-soft); font-size: 14.5px; line-height: 1.85;
  margin-left: 24px; margin-bottom: 18px;
}
.faq dd strong { color: var(--ink); font-weight: 500; }
.faq dd ul { margin-top: 8px; margin-bottom: 0; }

/* ───────────── footer ───────────── */
footer {
  border-top: 1px solid var(--rule);
  padding: 48px 0 56px;
  background: var(--paper);
}
footer .wrap {
  max-width: var(--max);
  display: grid; grid-template-columns: 1.5fr 1fr 1fr 1fr;
  gap: 40px;
  font-size: 14px;
}
.ft-brand {
  font-family: var(--font-display); font-size: 18px; font-weight: 700;
  letter-spacing: 0.08em; color: var(--ink);
  margin-bottom: 8px;
}
.ft-tag {
  color: var(--ink-mute); font-size: 13px; line-height: 1.7;
  max-width: 280px;
}
footer h5 {
  font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.2em;
  color: var(--bronze-deep); text-transform: uppercase;
  margin-bottom: 14px; font-weight: 500;
}
footer ul { list-style: none; display: flex; flex-direction: column; gap: 8px; margin: 0; }
footer ul a {
  color: var(--ink-soft); text-decoration: none; font-size: 13px;
}
footer ul a:hover { color: var(--bronze-deep); }
footer ul .is-soon { color: var(--ink-mute); opacity: 0.6; cursor: default; font-size: 13px; }
.ft-copy {
  grid-column: 1 / -1;
  margin-top: 36px; padding-top: 24px;
  border-top: 1px solid var(--rule);
  display: flex; justify-content: space-between;
  font-family: var(--font-mono); font-size: 11px;
  letter-spacing: 0.15em; text-transform: uppercase;
  color: var(--ink-mute);
}

/* ───────────── download page ───────────── */
.download-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin: 32px 0 48px;
}
.platform-card {
  position: relative;
  display: flex;
  flex-direction: column;
  padding: 28px 24px 24px;
  background: var(--paper);
  border: 1px solid var(--rule);
  border-radius: 4px;
  transition: border-color .2s, transform .2s;
}
.platform-card:hover { border-color: var(--bronze); transform: translateY(-1px); }
.platform-card .pc-mark {
  font-size: 28px; line-height: 1;
  color: var(--bronze-deep);
  margin-bottom: 14px;
}
.platform-card h3 {
  font-family: var(--font-display); font-weight: 700;
  font-size: 19px; letter-spacing: 0.04em;
  color: var(--ink);
  margin-bottom: 6px;
}
.platform-card .pc-sub {
  font-family: var(--font-mono); font-size: 11px;
  letter-spacing: 0.14em; color: var(--ink-mute);
  text-transform: uppercase;
  margin-bottom: 16px;
}
.platform-card p {
  font-size: 14px; line-height: 1.7;
  color: var(--ink-soft);
  margin-bottom: 16px;
  flex-grow: 1;
}
.platform-card .pc-action {
  display: inline-flex; align-items: center; justify-content: center;
  padding: 10px 18px;
  background: var(--ink); color: var(--paper);
  text-decoration: none;
  border-radius: 3px;
  font-size: 13.5px; letter-spacing: 0.04em;
  border: 1px solid var(--ink);
  transition: background .2s, transform .2s;
}
.platform-card .pc-action:hover { background: var(--bronze-deep); border-color: var(--bronze-deep); transform: translateY(-1px); }
.platform-card .pc-action.is-soon {
  background: var(--paper-2); color: var(--ink-mute);
  border-color: var(--rule); cursor: default;
  pointer-events: none;
}
.apk-meta {
  margin-top: 40px;
  padding: 28px 32px;
  background: var(--paper-2);
  border: 1px solid var(--rule);
  border-radius: 3px;
}
.apk-meta h3 {
  font-family: var(--font-display); font-weight: 600;
  font-size: 17px; letter-spacing: 0.05em;
  color: var(--ink); margin-bottom: 14px;
}
.apk-meta dl {
  display: grid; grid-template-columns: 140px 1fr;
  gap: 8px 16px;
  font-size: 13.5px;
}
.apk-meta dt {
  font-family: var(--font-mono); font-size: 11px;
  letter-spacing: 0.16em; text-transform: uppercase;
  color: var(--ink-mute);
  align-self: center;
}
.apk-meta dd {
  font-family: var(--font-mono); font-size: 12.5px;
  color: var(--ink-soft);
  word-break: break-all;
  line-height: 1.6;
}
.apk-meta dd.is-todo { color: var(--ink-mute); font-style: italic; }

.install-steps { counter-reset: step; margin: 32px 0 48px; }
.install-steps > li {
  list-style: none;
  position: relative;
  padding: 18px 0 18px 56px;
  border-bottom: 1px solid var(--rule-soft);
}
.install-steps > li:last-child { border-bottom: none; }
.install-steps > li::before {
  counter-increment: step;
  content: counter(step, decimal-leading-zero);
  position: absolute; left: 0; top: 22px;
  width: 36px; height: 36px;
  display: grid; place-items: center;
  font-family: var(--font-mono); font-size: 12px;
  letter-spacing: 0.06em;
  background: var(--paper); color: var(--bronze-deep);
  border: 1px solid var(--bronze);
  border-radius: 2px;
}
.install-steps strong {
  display: block;
  font-family: var(--font-display); font-weight: 600;
  font-size: 16px; color: var(--ink);
  margin-bottom: 4px;
  letter-spacing: 0.04em;
}
.install-steps span {
  display: block;
  font-size: 14px; line-height: 1.7;
  color: var(--ink-soft);
}
.install-steps em {
  font-style: normal;
  font-family: var(--font-mono); font-size: 12.5px;
  background: var(--paper-2);
  padding: 1px 6px;
  border-radius: 2px;
  color: var(--bronze-deep);
}

.vendor-grid {
  display: grid; grid-template-columns: repeat(2, 1fr);
  gap: 12px 24px;
  margin: 24px 0 32px;
}
.vendor-grid li {
  list-style: none;
  font-size: 14px; line-height: 1.7;
  color: var(--ink-soft);
  padding-left: 18px;
  position: relative;
}
.vendor-grid li::before {
  content: ""; position: absolute; left: 0; top: 12px;
  width: 6px; height: 6px;
  background: var(--bronze);
}
.vendor-grid strong { color: var(--ink); }

/* ───────────── responsive ───────────── */
@media (max-width: 720px) {
  .wrap { padding: 0 20px; }
  article.legal { padding: 48px 0 64px; }
  article.legal h2 { font-size: 20px; margin-top: 40px; }
  footer .wrap { grid-template-columns: 1fr 1fr; }
  nav.links a:not(.lang-pick a) { font-size: 13px; }
  .brand-en { display: none; }
  .download-grid { grid-template-columns: 1fr; gap: 14px; }
  .apk-meta { padding: 22px 20px; }
  .apk-meta dl { grid-template-columns: 1fr; gap: 4px 0; margin-bottom: 14px; }
  .apk-meta dl > * + dt { margin-top: 12px; }
  .vendor-grid { grid-template-columns: 1fr; }
  .install-steps > li { padding-left: 48px; }
}
@media (max-width: 480px) {
  footer .wrap { grid-template-columns: 1fr; }
  .ft-copy { flex-direction: column; gap: 8px; }
  nav.links { gap: 14px; }
}