:root {
  --primary: #185fa5;
  --primary-pressed: #0a3f77;
  --accent: #ef9f27;
  --canvas: #f8f9fc;
  --surface: #ffffff;
  --surface-tint: #e6f1fb;
  --border: #d8e2ee;
  --text-primary: #042c53;
  --text-secondary: #6b7280;
  --text-disabled: #a7afba;
  --radius-sm: 12px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --shadow-1: 0 4px 16px rgba(24, 95, 165, 0.06);
  --max: 720px;
  --max-wide: 960px;
  --font: "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font);
  color: var(--text-primary);
  background: var(--canvas);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--primary);
  text-decoration: none;
}

a:hover {
  color: var(--primary-pressed);
  text-decoration: underline;
}

img {
  max-width: 100%;
  display: block;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(248, 249, 252, 0.92);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}

.site-header__inner,
.site-footer__inner,
.wrap {
  width: min(100% - 2rem, var(--max-wide));
  margin-inline: auto;
}

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  min-height: 64px;
}

.brand {
  display: inline-flex;
  align-items: baseline;
  gap: 0;
  font-weight: 700;
  font-size: 1.35rem;
  letter-spacing: -0.02em;
  color: var(--text-primary);
  text-decoration: none;
}

.brand:hover {
  text-decoration: none;
}

.brand__accent {
  color: var(--accent);
}

.nav {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.75rem 1.25rem;
  font-size: 0.95rem;
}

.nav a {
  color: var(--text-secondary);
  text-decoration: none;
}

.nav a:hover,
.nav a[aria-current="page"] {
  color: var(--primary);
}

.lang-switch {
  display: inline-flex;
  border: 1px solid var(--border);
  border-radius: 999px;
  overflow: hidden;
  background: var(--surface);
}

.lang-switch button {
  appearance: none;
  border: 0;
  background: transparent;
  color: var(--text-secondary);
  font: inherit;
  font-size: 0.85rem;
  padding: 0.35rem 0.7rem;
  cursor: pointer;
}

.lang-switch button[aria-pressed="true"] {
  background: var(--surface-tint);
  color: var(--primary);
  font-weight: 600;
}

.hero {
  padding: 4.5rem 0 3.5rem;
  background:
    radial-gradient(1200px 480px at 10% -10%, rgba(24, 95, 165, 0.12), transparent 60%),
    radial-gradient(900px 420px at 90% 0%, rgba(239, 159, 39, 0.14), transparent 55%),
    var(--canvas);
}

.hero__inner {
  width: min(100% - 2rem, var(--max-wide));
  margin-inline: auto;
  display: grid;
  gap: 2rem;
}

@media (min-width: 800px) {
  .hero__inner {
    grid-template-columns: 1.2fr 0.8fr;
    align-items: center;
  }
}

.hero h1 {
  margin: 0 0 0.75rem;
  font-size: clamp(2rem, 4vw, 3rem);
  line-height: 1.15;
  letter-spacing: -0.03em;
}

.hero p {
  margin: 0 0 1.5rem;
  color: var(--text-secondary);
  font-size: 1.1rem;
  max-width: 36rem;
}

.cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  min-height: 48px;
  padding: 0.7rem 1.25rem;
  border-radius: var(--radius-lg);
  font-weight: 600;
  text-decoration: none;
  border: 1px solid transparent;
  transition: background 0.15s ease, color 0.15s ease, border-color 0.15s ease;
}

.btn:hover {
  text-decoration: none;
}

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

.btn--primary:hover {
  background: var(--primary-pressed);
  color: #fff;
}

.btn--secondary {
  background: var(--surface);
  color: var(--primary);
  border-color: var(--border);
}

.btn--secondary:hover {
  background: var(--surface-tint);
  color: var(--primary-pressed);
}

.hero-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-1);
  padding: 1.5rem;
}

.hero-card h2 {
  margin: 0 0 0.75rem;
  font-size: 1.15rem;
}

.hero-card ul {
  margin: 0;
  padding-left: 1.1rem;
  color: var(--text-secondary);
}

.hero-card li + li {
  margin-top: 0.4rem;
}

.section {
  padding: 2.5rem 0;
}

.section h2 {
  margin: 0 0 1rem;
  font-size: 1.5rem;
}

.grid-2 {
  display: grid;
  gap: 1rem;
}

@media (min-width: 720px) {
  .grid-2 {
    grid-template-columns: repeat(2, 1fr);
  }
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.25rem;
  box-shadow: var(--shadow-1);
}

.card h3 {
  margin: 0 0 0.5rem;
  font-size: 1.05rem;
}

.card p {
  margin: 0;
  color: var(--text-secondary);
  font-size: 0.95rem;
}

.site-footer {
  margin-top: 3rem;
  border-top: 1px solid var(--border);
  background: var(--surface);
  padding: 2rem 0;
  color: var(--text-secondary);
  font-size: 0.9rem;
}

.site-footer__inner {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  justify-content: space-between;
}

.site-footer nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem 1.25rem;
}

.legal {
  width: min(100% - 2rem, var(--max));
  margin: 2.5rem auto 4rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-1);
  padding: 1.75rem 1.5rem 2rem;
}

@media (min-width: 640px) {
  .legal {
    padding: 2.25rem 2.5rem 2.75rem;
  }
}

.legal__meta {
  color: var(--text-secondary);
  font-size: 0.95rem;
  margin: 0 0 1.5rem;
}

.legal h1 {
  margin: 0 0 0.5rem;
  font-size: clamp(1.75rem, 3vw, 2.25rem);
  line-height: 1.2;
}

.legal h2 {
  margin: 2rem 0 0.75rem;
  font-size: 1.2rem;
}

.legal h3 {
  margin: 1.25rem 0 0.5rem;
  font-size: 1.05rem;
}

.legal p,
.legal li {
  color: var(--text-primary);
}

.legal ul {
  padding-left: 1.2rem;
}

.legal li + li {
  margin-top: 0.35rem;
}

.legal [data-lang] {
  display: none;
}

html[lang="en"] .legal [data-lang="en"],
html[lang="zh"] .legal [data-lang="zh"],
html[lang="en"] [data-i18n-en],
html[lang="zh"] [data-i18n-zh] {
  display: block;
}

html[lang="en"] [data-i18n-zh],
html[lang="zh"] [data-i18n-en] {
  display: none;
}

html[lang="en"] .inline-en,
html[lang="zh"] .inline-zh {
  display: inline;
}

html[lang="en"] .inline-zh,
html[lang="zh"] .inline-en {
  display: none;
}

.note {
  background: var(--surface-tint);
  border-radius: var(--radius-md);
  padding: 0.9rem 1rem;
  color: var(--text-secondary);
  font-size: 0.95rem;
}