:root {
  --bg: #ffffff;
  --bg-2: #f5f5f7;
  --fg: #1d1d1f;
  --fg-2: #6e6e73;
  --line: #e5e5ea;
  --action: #0a66e4;
  --action-fg: #ffffff;
  --card: #ffffff;
  --shadow: 0 24px 60px rgba(0, 0, 0, 0.12), 0 2px 8px rgba(0, 0, 0, 0.06);
  --radius: 22px;
  --font: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Inter", "PingFang SC", "Hiragino Sans GB",
    "Noto Sans SC", "Microsoft YaHei", "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #000000;
    --bg-2: #1c1c1e;
    --fg: #f5f5f7;
    --fg-2: #a1a1a6;
    --line: #2c2c2e;
    --action: #2f7cf6;
    --card: #1c1c1e;
    --shadow: 0 24px 60px rgba(0, 0, 0, 0.6), 0 2px 8px rgba(0, 0, 0, 0.4);
  }
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: var(--font);
  font-size: 17px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
a { color: inherit; text-decoration: none; }
p a { color: var(--action); }
img { display: block; max-width: 100%; height: auto; }
h1, h2, h3 { margin: 0; letter-spacing: -0.02em; }
h2 { font-size: 34px; line-height: 1.15; font-weight: 700; }
h3 { font-size: 19px; line-height: 1.3; font-weight: 600; }

/* Language: every phrase exists twice; the document's data-lang picks one. */
i.en, i.zh { font-style: normal; }
html[data-lang="en"] .zh, html[data-lang="zh"] .en { display: none; }
html[data-lang="zh"] body { letter-spacing: 0; }

/* Nav */
.nav {
  position: sticky; top: 0; z-index: 10;
  display: flex; align-items: center; justify-content: space-between;
  padding: 14px clamp(20px, 5vw, 56px);
  background: color-mix(in srgb, var(--bg) 78%, transparent);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid color-mix(in srgb, var(--line) 60%, transparent);
}
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 18px; letter-spacing: -0.01em; }
.links { display: flex; align-items: center; gap: 26px; font-size: 14px; color: var(--fg-2); }
.links a:hover { color: var(--fg); }
.lang {
  font: inherit; color: var(--fg-2); background: none; border: 1px solid var(--line); border-radius: 999px;
  padding: 5px 12px; cursor: pointer;
}
.lang:hover { color: var(--fg); border-color: var(--fg-2); }
@media (max-width: 640px) { .links a:not([href^="http"]) { display: none; } }

/* Hero */
main { max-width: 1120px; margin: 0 auto; padding: 0 clamp(20px, 5vw, 56px); }
.hero { text-align: center; padding: clamp(72px, 12vw, 136px) 0 40px; }
.eyebrow { margin: 0 0 18px; font-size: 14px; font-weight: 600; letter-spacing: 0.02em; color: var(--fg-2); text-transform: none; }
.hero h1 { font-size: clamp(32px, 5.4vw, 60px); line-height: 1.08; font-weight: 700; letter-spacing: -0.03em; }
.lede { max-width: 760px; margin: 26px auto 0; font-size: clamp(18px, 2.1vw, 21px); line-height: 1.5; color: var(--fg-2); }
.cta { display: flex; flex-wrap: wrap; justify-content: center; gap: 12px; margin-top: 34px; }
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 13px 24px; border-radius: 999px; font-weight: 600; font-size: 16px;
  border: 1px solid var(--line); color: var(--fg); background: var(--bg);
  transition: transform 0.15s ease, background 0.15s ease, border-color 0.15s ease;
}
.btn:hover { transform: translateY(-1px); border-color: var(--fg-2); }
.btn.primary { background: var(--action); color: var(--action-fg); border-color: var(--action); }
.btn.primary:hover { filter: brightness(1.06); }
.fine { margin: 18px 0 0; font-size: 13px; color: var(--fg-2); }
.fine code { font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size: 12px; }

/* Moods strip */
.moods { margin: 40px auto 0; max-width: 980px; text-align: center; }
.moods img { width: 100%; }
.moods figcaption { margin-top: 16px; font-size: 15px; color: var(--fg-2); }

/* Screens */
.shots {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: clamp(14px, 2.5vw, 28px);
  margin: clamp(56px, 8vw, 96px) 0 0;
}
.shots figure { margin: 0; text-align: center; }
.shots img {
  border-radius: clamp(18px, 3vw, 32px);
  box-shadow: var(--shadow);
  border: 1px solid color-mix(in srgb, var(--line) 70%, transparent);
  background: var(--bg-2);
}
.shots figcaption { margin-top: 14px; font-size: 15px; font-weight: 500; color: var(--fg-2); }
@media (max-width: 760px) { .shots { grid-template-columns: repeat(2, 1fr); } }

/* Sections */
section h2 { text-align: center; }
.grid { padding: clamp(80px, 11vw, 140px) 0 0; }
.grid ul {
  list-style: none; margin: 40px 0 0; padding: 0;
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px;
}
.grid li { background: var(--bg-2); border-radius: var(--radius); padding: 28px 26px 26px; }
.grid li p { margin: 10px 0 0; color: var(--fg-2); font-size: 15.5px; line-height: 1.55; }
@media (max-width: 900px) { .grid ul { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 560px) { .grid ul { grid-template-columns: 1fr; } }

section .sub { max-width: 720px; margin: 14px auto 0; text-align: center; color: var(--fg-2); font-size: 16px; }
.pillars ul { grid-template-columns: repeat(4, 1fr); }
.pillars li { position: relative; }
.pillars .status {
  display: inline-block; margin-bottom: 14px; font-size: 11px; font-weight: 600; letter-spacing: 0.04em;
  padding: 3px 9px; border-radius: 999px; background: var(--line); color: var(--fg-2);
}
.pillars .status.now { background: var(--action); color: var(--action-fg); }
@media (max-width: 1000px) { .pillars ul { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 560px) { .pillars ul { grid-template-columns: 1fr; } }

.compare { padding: clamp(80px, 11vw, 140px) 0 0; }
.compare .table { margin: 36px auto 0; max-width: 1040px; overflow-x: auto; -webkit-overflow-scrolling: touch; }
.compare table { width: 100%; border-collapse: collapse; font-size: 14.5px; line-height: 1.5; min-width: 720px; }
.compare th, .compare td { text-align: left; vertical-align: top; padding: 14px 14px; border-bottom: 1px solid var(--line); }
.compare thead th { font-size: 13px; font-weight: 600; letter-spacing: 0.02em; color: var(--fg-2); border-bottom: 1px solid var(--fg-2); }
.compare thead th:last-child { color: var(--action); }
.compare tbody th { font-weight: 600; color: var(--fg); width: 18%; }
.compare tbody td { color: var(--fg-2); }
.compare tbody td:last-child { color: var(--fg); }

.how { padding: clamp(80px, 11vw, 140px) 0 0; }
.cols { display: grid; grid-template-columns: repeat(4, 1fr); gap: clamp(24px, 3vw, 40px); margin-top: 40px; }
@media (max-width: 1000px) { .cols { grid-template-columns: repeat(2, 1fr); } }
.cols p { margin: 10px 0 0; color: var(--fg-2); font-size: 15.5px; line-height: 1.55; }
@media (max-width: 760px) { .cols { grid-template-columns: 1fr; gap: 28px; } }

.versions { padding: clamp(80px, 11vw, 140px) 0 0; }
.versions ol { list-style: none; margin: 36px auto 0; padding: 0; max-width: 820px; border-top: 1px solid var(--line); }
.versions li {
  display: grid; grid-template-columns: 64px 140px 1fr; gap: 16px; align-items: baseline;
  padding: 16px 4px; border-bottom: 1px solid var(--line); font-size: 15.5px;
}
.versions li a, .versions li .ver { font-variant-numeric: tabular-nums; font-weight: 600; color: var(--action); }
.versions li .ver { color: var(--fg-2); }
.versions .name { font-weight: 600; }
.versions .what { color: var(--fg-2); }
.versions .current .name::after {
  content: "latest"; margin-left: 10px; font-size: 11px; font-weight: 600; letter-spacing: 0.04em;
  padding: 2px 8px; border-radius: 999px; background: var(--action); color: var(--action-fg); vertical-align: middle;
}
html[data-lang="zh"] .versions .current .name::after { content: "最新"; }
.versions .next { color: var(--fg-2); }
.versions li[hidden] { display: none; }
.versions .earlier { display: block; padding: 0; }
.versions .earlier button {
  display: block; width: 100%; padding: 14px 4px; border: 0; background: none; cursor: pointer;
  font: inherit; font-size: 14.5px; font-weight: 600; color: var(--action); text-align: center;
}
.versions .earlier button:hover { text-decoration: underline; }
.versions .earlier .hide, .versions .earlier.open .show { display: none; }
.versions .earlier.open .hide { display: inline; }
.versions .more { text-align: center; margin: 28px 0 0; font-size: 15px; }
.versions .more a { color: var(--action); }
@media (max-width: 560px) {
  .versions li { grid-template-columns: 56px 1fr; }
  .versions li .what { grid-column: 1 / -1; }
}

/* Footer */
footer { margin-top: clamp(80px, 11vw, 140px); padding: 36px clamp(20px, 5vw, 56px) 56px; border-top: 1px solid var(--line); }
footer nav { display: flex; flex-wrap: wrap; justify-content: center; gap: 22px; font-size: 14px; color: var(--fg-2); }
footer nav a:hover { color: var(--fg); }
footer p { max-width: 760px; margin: 22px auto 0; text-align: center; font-size: 13px; color: var(--fg-2); }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .btn { transition: none; }
}