:root {
  --bg: #f3f6f4;
  --ink: #17211c;
  --muted: #5d6b64;
  --line: rgba(23, 33, 28, 0.08);
  --card: #ffffff;
  --green: #157a45;
  --green-deep: #0f6538;
  --green-soft: #e7f5ec;
  --shadow: 0 16px 40px rgba(23, 40, 32, 0.06);
  --radius: 22px;
  --max: 1120px;
  --nav: 64px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(900px 420px at 8% -10%, rgba(120, 190, 150, 0.28), transparent 60%),
    radial-gradient(700px 380px at 92% 0%, rgba(190, 220, 200, 0.35), transparent 55%),
    var(--bg);
  font-family: "PingFang SC", "Hiragino Sans GB", "Noto Sans SC", "Microsoft YaHei", sans-serif;
  font-size: 16px;
  line-height: 1.6;
}

a { color: inherit; }

.skip {
  position: absolute;
  left: 12px;
  top: 12px;
  transform: translateY(-200%);
  background: var(--ink);
  color: #fff;
  padding: 8px 12px;
  border-radius: 8px;
  z-index: 20;
}

.skip:focus { transform: none; }

.nav {
  position: sticky;
  top: 0;
  z-index: 10;
  height: var(--nav);
  display: flex;
  align-items: center;
  backdrop-filter: blur(14px);
  background: rgba(243, 246, 244, 0.86);
  border-bottom: 1px solid transparent;
}

.nav-inner,
.wrap {
  width: min(var(--max), calc(100% - 40px));
  margin: 0 auto;
}

.nav-inner {
  display: flex;
  align-items: center;
  gap: 28px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  font-weight: 650;
  letter-spacing: -0.01em;
}

.mark {
  width: 28px;
  height: 28px;
  display: block;
}

.ver {
  color: var(--muted);
  font-weight: 500;
  font-size: 13px;
}

.nav-links {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 18px;
}

.nav-links a {
  text-decoration: none;
  color: #3d4a44;
  font-size: 14px;
}

.nav-links a:hover { color: var(--ink); }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0 18px;
  border-radius: 999px;
  text-decoration: none;
  font-weight: 650;
  border: 1px solid transparent;
  cursor: pointer;
  transition: background 160ms ease, transform 160ms ease, border-color 160ms ease;
}

.btn:focus-visible,
.nav-links a:focus-visible,
.dl:focus-visible {
  outline: 2px solid var(--green);
  outline-offset: 3px;
}

.btn-green {
  background: var(--green);
  color: #fff;
}

.btn-green:hover { background: var(--green-deep); }

.btn-ghost {
  background: #fff;
  border-color: var(--line);
  color: var(--ink);
}

.btn-ghost:hover { border-color: rgba(21, 122, 69, 0.35); }

.nav-links a.btn-nav {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 36px;
  padding: 0 14px;
  font-size: 14px;
  line-height: 1;
  color: #fff;
}

.nav-links a.btn-nav:hover {
  color: #fff;
  background: var(--green-deep);
}

.hero {
  display: grid;
  grid-template-columns: 1.08fr 0.92fr;
  grid-template-areas:
    "intro downloads"
    "preview downloads";
  gap: 28px 36px;
  padding: 42px 0 28px;
  align-items: start;
}

.intro { grid-area: intro; }
.panel { grid-area: downloads; }
.preview { grid-area: preview; align-self: end; }

h1 {
  margin: 0 0 14px;
  font-size: 44px;
  line-height: 1.18;
  letter-spacing: -0.03em;
  font-weight: 750;
}

.lede {
  margin: 0 0 18px;
  max-width: 38em;
  color: #3e4c45;
}

.chips {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 22px;
}

.chip {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 4px 10px;
  font-size: 13px;
  color: #3e4c45;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 14px;
}

.fine {
  margin: 0;
  color: var(--muted);
  font-size: 13px;
}

.panel h2,
.side-card h2,
.section h2 {
  margin: 0 0 6px;
  font-size: 20px;
  letter-spacing: -0.02em;
}

.panel > p,
.side-card p {
  margin: 0 0 14px;
  color: var(--muted);
  font-size: 14px;
}

.os-card,
.side-card,
.preview,
.step {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.os-card {
  padding: 18px 18px 16px;
  margin-bottom: 14px;
}

.os-card header {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 12px;
}

.os-card h3 {
  margin: 0;
  font-size: 18px;
}

.os-card p {
  margin: 4px 0 0;
  color: var(--muted);
  font-size: 13px;
}

.size {
  align-self: center;
  font-size: 13px;
  color: var(--muted);
  white-space: nowrap;
}

.dl {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 2px;
  width: 100%;
  min-height: 56px;
  border-radius: 999px;
  background: var(--green);
  color: #fff;
  text-decoration: none;
  font-weight: 700;
}

.dl small {
  font-weight: 500;
  font-size: 12px;
  opacity: 0.86;
}

.dl:hover { background: var(--green-deep); }

.dl:active { transform: translateY(1px); }

.dl.is-off {
  background: #d7ddd9;
  color: #5c675f;
  pointer-events: none;
}

.side {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}

.side-card { padding: 18px; }

.side-card p:last-child { margin-bottom: 0; }

.preview {
  padding: 14px;
  margin-top: 8px;
}

.preview-top {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 4px 6px 12px;
}

.dots { display: flex; gap: 6px; }

.dots i {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  display: block;
  background: #d5ddd8;
}

.dots i:first-child { background: #f0b4a8; }
.dots i:nth-child(2) { background: #f3d48a; }
.dots i:nth-child(3) { background: #b7d7b0; }

.preview-top strong { font-size: 13px; }

.tabs {
  display: flex;
  gap: 8px;
  margin-bottom: 12px;
}

.tab {
  border-radius: 10px;
  padding: 6px 12px;
  font-size: 13px;
  background: #f4f7f5;
  color: var(--muted);
}

.tab.on {
  background: #fff;
  color: var(--ink);
  box-shadow: inset 0 0 0 1px var(--line);
  font-weight: 650;
}

.row {
  display: grid;
  grid-template-columns: 1.4fr 0.6fr 0.7fr 1fr;
  gap: 8px;
  align-items: center;
  padding: 12px;
  border-radius: 14px;
  background: #f7faf8;
  margin-bottom: 8px;
}

.row b { font-weight: 650; font-size: 14px; }

.row span,
.meter em {
  color: var(--muted);
  font-size: 12px;
  font-style: normal;
}

.badge {
  justify-self: start;
  background: var(--green-soft);
  color: var(--green-deep);
  border-radius: 999px;
  padding: 2px 8px;
  font-size: 12px;
  font-weight: 650;
}

.meter {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.bar {
  height: 6px;
  border-radius: 99px;
  background: #e3ebe6;
  overflow: hidden;
}

.bar i {
  display: block;
  height: 100%;
  width: 62%;
  background: var(--green);
}

.bar.low i { width: 28%; }

.section {
  padding: 18px 0 64px;
}

.steps {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
  margin-top: 14px;
}

.step { padding: 18px 20px; }

.step h3 { margin: 0 0 8px; font-size: 16px; }

.step ol {
  margin: 0;
  padding-left: 18px;
  color: #3e4c45;
}

.step li + li { margin-top: 6px; }

.step code {
  padding: 1px 6px;
  border-radius: 6px;
  background: #eef1f4;
  color: #24302b;
  font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  font-size: 0.92em;
  word-break: break-all;
}

.foot {
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 13px;
  padding: 18px 0 28px;
}

@media (max-width: 860px) {
  h1 { font-size: 32px; }
  .hero {
    grid-template-columns: 1fr;
    grid-template-areas:
      "intro"
      "downloads"
      "preview";
  }
  .side,
  .steps,
  .row { grid-template-columns: 1fr; }
  .nav-links a:not(.btn) { display: none; }
  .wrap, .nav-inner { width: min(var(--max), calc(100% - 28px)); }
}

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