:root {
  --bg-page: #fafafa;
  --bg-surface: #ffffff;
  --bg-subtle: #f4f5f7;
  --text-primary: #111827;
  --text-secondary: #4b5563;
  --text-muted: #6b7280;
  --border-subtle: #e5e7eb;
  --border-hover: #cbd5e1;
  --accent: #0f172a;
  --accent-blue: #1d4ed8;
  --accent-blue-subtle: #eff6ff;
  --accent-blue-border: #bfdbfe;
  --shadow-sm: 0 1px 2px 0 rgba(15, 23, 42, 0.03);
  --shadow-md: 0 10px 30px -10px rgba(15, 23, 42, 0.06), 0 4px 6px -4px rgba(15, 23, 42, 0.03);
  --radius-md: 12px;
  --radius-lg: 16px;
  --container-max: 1120px;
  --font-sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "HarmonyOS Sans SC", "Microsoft YaHei", "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
}

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  background-color: var(--bg-page);
  color: var(--text-primary);
  font-family: var(--font-sans);
  line-height: 1.6;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background-color: var(--bg-page);
  background-image:
    radial-gradient(circle at 50% 0%, rgba(29, 78, 216, 0.045) 0%, transparent 60%),
    linear-gradient(to bottom, #ffffff 0%, #fafafa 100%);
  color: var(--text-primary);
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a {
  color: inherit;
  text-decoration: none;
  transition: color 0.18s ease, background-color 0.18s ease, border-color 0.18s ease, transform 0.18s ease, box-shadow 0.18s ease;
}

.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 24px;
}

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.86);
  backdrop-filter: saturate(180%) blur(12px);
  -webkit-backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--border-subtle);
}

.header-inner {
  height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: var(--text-primary);
}

.brand-logo {
  width: 34px;
  height: 34px;
  object-fit: contain;
  display: block;
  flex-shrink: 0;
}

.brand-text {
  display: flex;
  align-items: baseline;
  gap: 8px;
  line-height: 1;
}

.brand-name {
  font-size: 1.125rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--text-primary);
}

.brand-sub {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  padding-left: 8px;
  border-left: 1px solid var(--border-subtle);
}

.lang-switch {
  display: inline-flex;
  align-items: center;
  gap: 2px;
  padding: 3px;
  background: var(--bg-subtle);
  border: 1px solid var(--border-subtle);
  border-radius: 999px;
  font-size: 0.8125rem;
  font-weight: 500;
  line-height: 1;
}

.lang-switch .lang-item {
  padding: 6px 10px;
  border-radius: 999px;
  color: var(--text-secondary);
}

.lang-switch .lang-item:hover {
  color: var(--text-primary);
}

.lang-switch .lang-item.is-active {
  background: var(--bg-surface);
  color: var(--text-primary);
  font-weight: 600;
  box-shadow: var(--shadow-sm);
}

.lang-switch .lang-divider {
  color: #cbd5e1;
  font-size: 0.75rem;
  user-select: none;
  padding: 0 2px;
}

/* Main Content */
main {
  flex: 1;
}

/* Hero Section */
.hero {
  padding: 96px 0 72px;
  position: relative;
}

.hero-inner {
  max-width: 820px;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  border-radius: 999px;
  background-color: var(--accent-blue-subtle);
  border: 1px solid var(--accent-blue-border);
  color: var(--accent-blue);
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  margin-bottom: 24px;
}

.eyebrow-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: var(--accent-blue);
}

.hero-title {
  font-size: clamp(2rem, 4.2vw, 3.25rem);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.025em;
  color: var(--text-primary);
  margin-bottom: 24px;
}

.hero-subtitle {
  font-size: clamp(1rem, 1.5vw, 1.15rem);
  line-height: 1.8;
  color: var(--text-secondary);
  max-width: 720px;
  margin-bottom: 36px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 16px;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 13px 26px;
  border-radius: 10px;
  background-color: var(--accent);
  color: #ffffff;
  font-size: 0.95rem;
  font-weight: 600;
  box-shadow: var(--shadow-sm);
}

.btn-primary:hover {
  background-color: #1e293b;
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.btn-primary svg {
  width: 16px;
  height: 16px;
  transition: transform 0.18s ease;
}

.btn-primary:hover svg {
  transform: translateX(2px);
}

/* Capabilities Section */
.capabilities {
  padding: 24px 0 84px;
}

.capabilities-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 24px;
}

.capability-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 32px 28px;
  display: flex;
  flex-direction: column;
  box-shadow: var(--shadow-sm);
  transition: border-color 0.2s ease, box-shadow 0.2s ease, transform 0.2s ease;
}

.capability-card:hover {
  border-color: var(--border-hover);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 24px;
}

.card-icon {
  width: 44px;
  height: 44px;
  border-radius: 10px;
  background: var(--bg-subtle);
  border: 1px solid var(--border-subtle);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: var(--text-primary);
}

.card-icon svg {
  width: 22px;
  height: 22px;
}

.card-index {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--text-muted);
  letter-spacing: 0.08em;
}

.card-title {
  font-size: 1.25rem;
  font-weight: 650;
  color: var(--text-primary);
  margin-bottom: 14px;
  letter-spacing: -0.01em;
}

.card-desc {
  font-size: 0.95rem;
  line-height: 1.75;
  color: var(--text-secondary);
  flex: 1;
}

/* Contact Section */
.contact-section {
  padding: 0 0 72px;
}

.contact-banner {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 32px 36px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 20px;
  box-shadow: var(--shadow-sm);
}

.contact-text {
  font-size: 1.05rem;
  font-weight: 500;
  color: var(--text-primary);
  line-height: 1.6;
}

.contact-email {
  font-family: var(--font-mono);
  font-weight: 600;
  color: var(--accent-blue);
  border-bottom: 1px solid transparent;
  word-break: break-all;
}

.contact-email:hover {
  border-bottom-color: var(--accent-blue);
}

/* Footer */
.site-footer {
  border-top: 1px solid var(--border-subtle);
  background: var(--bg-surface);
  padding: 28px 0;
  font-size: 0.875rem;
  color: var(--text-muted);
}

.footer-inner {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.footer-main {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px 24px;
}

.footer-copy {
  color: var(--text-secondary);
}

.footer-meta {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
}

.footer-icp {
  color: var(--text-muted);
  font-size: 0.85rem;
}

.footer-icp:hover {
  color: var(--text-primary);
  text-decoration: underline;
}

.footer-extensions[hidden] {
  display: none !important;
}

/* Responsive Breakpoints */
@media (max-width: 1023px) {
  .hero {
    padding: 72px 0 56px;
  }

  .capabilities-grid {
    grid-template-columns: 1fr;
    gap: 20px;
  }

  .capability-card {
    padding: 28px 24px;
  }
}

@media (max-width: 640px) {
  .container {
    padding: 0 20px;
  }

  .header-inner {
    height: 64px;
  }

  .brand-logo {
    width: 30px;
    height: 30px;
  }

  .brand-name {
    font-size: 1.05rem;
  }

  .hero {
    padding: 52px 0 44px;
  }

  .eyebrow {
    font-size: 0.72rem;
    padding: 5px 12px;
    margin-bottom: 18px;
  }

  .hero-title {
    font-size: 1.75rem;
    margin-bottom: 18px;
  }

  .hero-subtitle {
    font-size: 0.95rem;
    line-height: 1.7;
    margin-bottom: 28px;
  }

  .btn-primary {
    width: 100%;
    padding: 13px 20px;
  }

  .capabilities {
    padding: 12px 0 56px;
  }

  .contact-section {
    padding: 0 0 48px;
  }

  .contact-banner {
    padding: 24px 20px;
  }

  .contact-text {
    font-size: 0.95rem;
  }

  .footer-main {
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
  }
}