:root {
  --bg: #f7f7f5;
  --surface: #ffffff;
  --fg: #111113;
  --muted: #6b6b76;
  --line: #e8e8e4;
  --soft: #f0f0ec;
  --accent: #4f46e5;
  --accent-hover: #4338ca;
  --accent-soft: #eef2ff;
  --accent-ring: rgba(79, 70, 229, 0.14);
  --shadow-sm: 0 1px 2px rgba(17, 17, 19, 0.04);
  --shadow-md: 0 8px 24px rgba(17, 17, 19, 0.06), 0 2px 6px rgba(17, 17, 19, 0.04);
  --radius: 14px;
  --radius-sm: 10px;
  --max: 680px;
  --max-wide: 920px;
  --font: "Inter", system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }

html, body {
  margin: 0;
  min-height: 100%;
  background: var(--bg);
  color: var(--fg);
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

a { color: var(--accent); text-underline-offset: 3px; }
a:hover { color: var(--accent-hover); }
code {
  font-family: var(--mono);
  font-size: 0.88em;
  background: var(--soft);
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 0.12em 0.4em;
  color: var(--fg);
}

.app {
  max-width: var(--max-wide);
  margin: 0 auto;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  padding: 0 28px;
}

/* Header */
.top {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin: 0 -28px;
  padding: 14px 28px;
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: saturate(1.4) blur(12px);
  -webkit-backdrop-filter: saturate(1.4) blur(12px);
  border-bottom: 1px solid transparent;
  transition: border-color 0.2s ease, background 0.2s ease;
}
.top::after {
  content: "";
  position: absolute;
  left: 28px;
  right: 28px;
  bottom: 0;
  height: 1px;
  background: var(--line);
  opacity: 0.9;
}
.brand {
  display: flex;
  gap: 11px;
  align-items: center;
  text-decoration: none;
  color: inherit;
  min-width: 0;
}
.brand:hover { color: inherit; opacity: 1; }
.brand-mark {
  width: 30px;
  height: 30px;
  border-radius: 9px;
  background: linear-gradient(145deg, #1a1a1f 0%, #111113 100%);
  color: #fff;
  display: grid;
  place-items: center;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: -0.03em;
  flex: 0 0 auto;
  box-shadow: inset 0 1px 0 rgba(255,255,255,0.12), var(--shadow-sm);
}
.brand-name {
  margin: 0;
  font-size: 15px;
  font-weight: 600;
  letter-spacing: -0.02em;
}
.brand p {
  margin: 1px 0 0;
  font-size: 12px;
  color: var(--muted);
  letter-spacing: 0;
  font-weight: 450;
}
.nav { display: flex; align-items: center; gap: 8px; }
.ghost {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 36px;
  padding: 0 14px;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: var(--surface);
  color: var(--fg) !important;
  font-size: 13px;
  font-weight: 500;
  text-decoration: none;
  font-family: inherit;
  box-shadow: var(--shadow-sm);
  transition: background 0.15s ease, border-color 0.15s ease, box-shadow 0.15s ease;
}
.ghost:hover {
  background: var(--soft);
  border-color: #d8d8d2;
  opacity: 1;
  color: var(--fg) !important;
}

/* Home hero */
.hero {
  padding: 80px 0 52px;
  max-width: 620px;
}
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin: 0 0 20px;
  padding: 5px 12px 5px 8px;
  font-size: 12.5px;
  font-weight: 500;
  color: var(--accent);
  letter-spacing: 0.01em;
  background: var(--accent-soft);
  border: 1px solid color-mix(in srgb, var(--accent) 16%, transparent);
  border-radius: 999px;
}
.eyebrow::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-ring);
}
.hero h1 {
  margin: 0 0 22px;
  font-size: clamp(40px, 6vw, 52px);
  line-height: 1.05;
  letter-spacing: -0.04em;
  font-weight: 700;
}
.lede {
  margin: 0 0 14px;
  font-size: 18.5px;
  line-height: 1.55;
  color: #3f3f46;
  max-width: 34em;
  letter-spacing: -0.01em;
}
.lede.zh, .zh {
  margin: 0;
  font-size: 15px;
  line-height: 1.65;
  color: var(--muted);
}

/* Product grid (home) */
.products {
  padding: 4px 0 64px;
}
.products h2 {
  margin: 0 0 18px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
}
.product-grid {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 14px;
}
.product-card {
  display: flex;
  flex-direction: column;
  gap: 14px;
  padding: 22px 22px 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  text-decoration: none;
  color: inherit;
  background: var(--surface);
  box-shadow: var(--shadow-sm);
  transition:
    border-color 0.18s ease,
    background 0.18s ease,
    box-shadow 0.18s ease,
    transform 0.18s ease;
}
.product-card:hover {
  border-color: color-mix(in srgb, var(--accent) 28%, var(--line));
  background: var(--surface);
  box-shadow: var(--shadow-md), 0 0 0 3px var(--accent-ring);
  transform: translateY(-2px);
  opacity: 1;
  color: inherit;
}
.product-card .card-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}
.product-icon {
  width: 36px;
  height: 36px;
  border-radius: 10px;
  display: grid;
  place-items: center;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: -0.02em;
  background: var(--soft);
  color: var(--fg);
  border: 1px solid var(--line);
  transition: background 0.18s ease, color 0.18s ease, border-color 0.18s ease;
}
.product-card:hover .product-icon {
  background: var(--accent-soft);
  color: var(--accent);
  border-color: color-mix(in srgb, var(--accent) 22%, var(--line));
}
.product-arrow {
  font-size: 18px;
  line-height: 1;
  color: #c4c4c8;
  transition: color 0.18s ease, transform 0.18s ease;
}
.product-card:hover .product-arrow {
  color: var(--accent);
  transform: translateX(3px);
}
.product-card strong {
  display: block;
  font-size: 16.5px;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 6px;
}
.product-card span {
  display: block;
  font-size: 14px;
  line-height: 1.55;
  color: var(--muted);
}

.section {
  padding: 0 0 64px;
  max-width: var(--max);
}
.section h2 {
  margin: 0 0 12px;
  font-size: 15px;
  font-weight: 700;
  letter-spacing: -0.01em;
}
.section p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.7;
  color: #3f3f46;
}

.note-soft {
  margin: 0 0 40px;
  font-size: 13px;
  color: var(--muted);
}

/* Article / product pages */
.article {
  padding: 52px 0 72px;
  max-width: var(--max);
}
.article h1 {
  margin: 0 0 18px;
  font-size: clamp(30px, 4.5vw, 38px);
  line-height: 1.12;
  letter-spacing: -0.03em;
  font-weight: 700;
}
.article h2 {
  margin: 48px 0 14px;
  font-size: 15px;
  font-weight: 700;
  letter-spacing: -0.01em;
}
.article p {
  margin: 0 0 14px;
  font-size: 15.5px;
  line-height: 1.7;
  color: #3f3f46;
}
.article .lead {
  font-size: 18px !important;
  line-height: 1.55 !important;
  color: #27272a !important;
  margin-bottom: 10px !important;
  letter-spacing: -0.01em;
}
.zh-gloss {
  margin: 0 0 10px;
  font-size: 13px;
  line-height: 1.55;
  color: var(--muted);
}
.caption {
  margin: 8px 0 0 !important;
  font-size: 13px !important;
  color: var(--muted) !important;
  line-height: 1.5 !important;
}

.audience {
  margin: 0 0 28px;
  padding: 13px 16px;
  border: 1px solid color-mix(in srgb, var(--accent) 18%, var(--line));
  border-radius: var(--radius-sm);
  background: var(--accent-soft);
  font-size: 13.5px;
  line-height: 1.55;
  color: #3730a3;
}

.cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 0 0 8px;
}
.cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 20px;
  border-radius: 10px;
  background: var(--accent);
  color: #fff !important;
  text-decoration: none;
  font-size: 14px;
  font-weight: 600;
  letter-spacing: -0.01em;
  border: 1px solid var(--accent);
  box-shadow: 0 1px 2px rgba(79, 70, 229, 0.25), inset 0 1px 0 rgba(255,255,255,0.12);
  transition: background 0.15s ease, box-shadow 0.15s ease, transform 0.15s ease;
}
.cta:hover {
  background: var(--accent-hover);
  opacity: 1;
  color: #fff !important;
  box-shadow: 0 4px 12px rgba(79, 70, 229, 0.28);
  transform: translateY(-1px);
}
.cta-disabled,
.cta-ghost {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 18px;
  border-radius: 10px;
  font-size: 14px;
  font-weight: 500;
  cursor: not-allowed;
  user-select: none;
  color: var(--muted);
  background: var(--surface);
  border: 1px solid var(--line);
}
.cta-ghost-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 18px;
  border-radius: 10px;
  text-decoration: none;
  font-size: 14px;
  font-weight: 500;
  background: var(--surface);
  border: 1px solid var(--line);
  color: var(--fg) !important;
  box-shadow: var(--shadow-sm);
  transition: background 0.15s ease, border-color 0.15s ease;
}
.cta-ghost-link:hover {
  background: var(--soft);
  opacity: 1;
  color: var(--fg) !important;
}

.note {
  background: var(--surface);
  border: 1px solid var(--line);
  border-left: 3px solid var(--accent);
  padding: 15px 17px;
  border-radius: var(--radius-sm);
  font-size: 13.5px;
  line-height: 1.65;
  color: #3f3f46;
  margin: 20px 0;
  box-shadow: var(--shadow-sm);
}

.plan-table-wrap { overflow-x: auto; margin: 14px 0 8px; -webkit-overflow-scrolling: touch; }
.plan-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 13.5px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}
.plan-table th,
.plan-table td {
  padding: 13px 15px;
  border-bottom: 1px solid var(--line);
  text-align: left;
  vertical-align: top;
  color: #3f3f46;
}
.plan-table thead th {
  background: var(--soft);
  font-weight: 600;
  color: var(--fg);
  font-size: 12px;
  letter-spacing: 0.03em;
  text-transform: uppercase;
}
.plan-table tbody th {
  font-weight: 600;
  white-space: nowrap;
  width: 34%;
  color: var(--fg);
}
.plan-table tr:last-child th,
.plan-table tr:last-child td { border-bottom: none; }

.steps {
  margin: 0 0 14px;
  padding-left: 1.25em;
  font-size: 15.5px;
  line-height: 1.7;
  color: #3f3f46;
}
.steps li { margin-bottom: 8px; }

.pill-row { display: flex; flex-wrap: wrap; gap: 8px; margin: 12px 0 4px; }
.pill {
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 7px 14px;
  font-size: 13px;
  color: #3f3f46 !important;
  text-decoration: none;
  background: var(--surface);
  box-shadow: var(--shadow-sm);
  transition: background 0.15s ease, border-color 0.15s ease;
}
.pill:hover {
  background: var(--soft);
  opacity: 1;
  color: var(--fg) !important;
}

/* Footer */
.foot, .legal {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 20px;
  margin-top: auto;
  padding: 28px 0 calc(32px + env(safe-area-inset-bottom));
  border-top: 1px solid var(--line);
}
.foot a, .legal a {
  color: var(--muted);
  font-size: 13px;
  text-decoration: none;
  min-height: 36px;
  display: inline-flex;
  align-items: center;
  transition: color 0.15s ease;
}
.foot a:hover, .legal a:hover { color: var(--fg); opacity: 1; }

@media (max-width: 640px) {
  .app { padding: 0 18px; }
  .top { margin: 0 -18px; padding: 12px 18px; }
  .top::after { left: 18px; right: 18px; }
  .hero { padding: 52px 0 40px; }
  .product-grid { grid-template-columns: 1fr; }
  .cta-row { flex-direction: column; }
  .cta, .cta-disabled, .cta-ghost, .cta-ghost-link { width: 100%; }
}

@media (prefers-reduced-motion: reduce) {
  .product-card,
  .product-arrow,
  .cta,
  .ghost { transition: none; }
  .product-card:hover,
  .cta:hover { transform: none; }
}

/* Brand positioning */
.lede.lead-zh,
.lead-zh {
  font-size: clamp(1.35rem, 2.6vw, 1.7rem);
  font-weight: 600;
  letter-spacing: -0.02em;
  line-height: 1.35;
  color: var(--fg);
  margin: 0 0 12px;
  max-width: 28ch;
}
.lede.zh.lead-zh { color: var(--fg); opacity: 1; }
.section-note {
  margin: -8px 0 20px;
  color: var(--muted);
  font-size: 0.95rem;
}
.brand-line {
  margin-top: -4px !important;
  margin-bottom: 14px !important;
  color: var(--muted);
}