/* =========================================================
   DeepWave Technology Limited · Website Styles
   Design tokens follow 01.公司vi/deepwave_colors.json
   ========================================================= */

/* ---------- 1. Reset & Base ---------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.65;
  color: var(--color-neutral-800);
  background: var(--color-neutral-50);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
img, svg { max-width: 100%; height: auto; display: block; }
a { color: var(--color-primary-500); text-decoration: none; transition: color .18s ease; }
a:hover { color: var(--color-primary-700); }
button { font: inherit; cursor: pointer; border: none; background: none; }

/* ---------- 2. Design Tokens ---------- */
:root {
  /* Colors */
  --color-primary-50:  #F3F8FF;
  --color-primary-100: #E3EFFF;
  --color-primary-200: #BEDBFF;
  --color-primary-400: #539FFF;
  --color-primary-500: #1A7FFF;
  --color-primary-600: #166BD8;
  --color-primary-700: #1258B2;
  --color-primary-800: #0E458C;
  --color-primary-900: #0A3266;

  --color-accent-300: #A1E0FF;
  --color-accent-500: #44C2FF;
  --color-accent-700: #2F87B2;

  --color-neutral-0:   #FFFFFF;
  --color-neutral-50:  #FAFAFA;
  --color-neutral-100: #F5F5F5;
  --color-neutral-200: #E5E5E5;
  --color-neutral-300: #D4D4D4;
  --color-neutral-400: #A3A3A3;
  --color-neutral-500: #737373;
  --color-neutral-600: #525252;
  --color-neutral-700: #404040;
  --color-neutral-800: #262626;
  --color-neutral-900: #171717;

  --color-success: #10B981;
  --color-warning: #F59E0B;
  --color-error:   #EF4444;

  /* Typography */
  --font-display: 'Space Grotesk', system-ui, -apple-system, 'Helvetica Neue', sans-serif;
  --font-body:    'Space Grotesk', 'Noto Sans SC', system-ui, -apple-system, 'PingFang SC', sans-serif;
  --font-mono:    'JetBrains Mono', ui-monospace, 'SFMono-Regular', Menlo, monospace;

  /* Layout */
  --container-max: 1200px;
  --container-px:  clamp(20px, 5vw, 48px);
  --section-py:    clamp(72px, 10vw, 128px);

  /* Radius */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --radius-xl: 28px;

  /* Shadow */
  --shadow-sm: 0 1px 2px rgba(10, 50, 102, 0.04), 0 1px 3px rgba(10, 50, 102, 0.06);
  --shadow-md: 0 4px 8px rgba(10, 50, 102, 0.06), 0 8px 24px rgba(10, 50, 102, 0.06);
  --shadow-lg: 0 8px 16px rgba(10, 50, 102, 0.08), 0 24px 48px rgba(10, 50, 102, 0.10);

  /* Transitions */
  --t-fast: 0.15s ease;
  --t-base: 0.25s ease;
  --t-slow: 0.4s ease;
}

/* ---------- 3. Typography ---------- */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: -0.02em;
  color: var(--color-neutral-900);
}
h1 { font-size: clamp(36px, 6vw, 64px); font-weight: 700; }
h2 { font-size: clamp(28px, 4vw, 44px); }
h3 { font-size: clamp(20px, 2.4vw, 26px); }
h4 { font-size: 18px; }
p { margin-bottom: 1em; max-width: 65ch; }
.lead {
  font-size: clamp(18px, 2vw, 22px);
  line-height: 1.55;
  color: var(--color-neutral-600);
}
.eyebrow {
  display: inline-block;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-primary-500);
  margin-bottom: 16px;
}
code, kbd, pre { font-family: var(--font-mono); font-size: 0.92em; }

/* ---------- 4. Layout ---------- */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding-inline: var(--container-px);
}
.section { padding-block: var(--section-py); }
.section--tight { padding-block: clamp(48px, 6vw, 80px); }
.grid { display: grid; gap: 24px; }
.grid--3col { grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); }
.grid--2col { grid-template-columns: repeat(auto-fit, minmax(320px, 1fr)); gap: 32px; }
.flex { display: flex; gap: 16px; }
.flex--center { align-items: center; justify-content: center; }
.flex--between { align-items: center; justify-content: space-between; }
.divider { height: 1px; background: var(--color-neutral-200); border: 0; margin-block: 48px; }

/* ---------- 5. Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 24px;
  border-radius: 999px;
  font-weight: 600;
  font-size: 15px;
  letter-spacing: -0.01em;
  transition: all var(--t-base);
  border: 2px solid transparent;
  white-space: nowrap;
}
.btn--primary {
  background: var(--color-primary-500);
  color: #fff;
}
.btn--primary:hover {
  background: var(--color-primary-700);
  color: #fff;
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}
.btn--secondary {
  background: transparent;
  color: var(--color-primary-500);
  border-color: var(--color-primary-500);
}
.btn--secondary:hover {
  background: var(--color-primary-500);
  color: #fff;
}
.btn--ghost {
  background: transparent;
  color: var(--color-neutral-700);
  padding: 10px 16px;
}
.btn--ghost:hover { color: var(--color-primary-500); }
.btn--lg { padding: 18px 32px; font-size: 17px; }
.btn--on-dark {
  background: rgba(255, 255, 255, 0.12);
  color: #fff;
  backdrop-filter: blur(10px);
  border-color: rgba(255, 255, 255, 0.24);
}
.btn--on-dark:hover {
  background: #fff;
  color: var(--color-primary-700);
}

/* ---------- 6. Header / Nav ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: saturate(150%) blur(20px);
  -webkit-backdrop-filter: saturate(150%) blur(20px);
  border-bottom: 1px solid transparent;
  transition: border-color var(--t-base);
}
.site-header.is-scrolled { border-bottom-color: var(--color-neutral-200); }
.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}
.nav__brand {
  display: flex;
  align-items: center;
  gap: 12px;
  font-weight: 700;
  font-size: 18px;
  letter-spacing: -0.02em;
  color: var(--color-neutral-900);
}
.nav__brand:hover { color: var(--color-primary-500); }
.nav__brand img { width: 32px; height: 32px; }
.nav__brand-zh {
  font-size: 12px;
  color: var(--color-neutral-500);
  margin-left: 4px;
  font-weight: 500;
}
.nav__menu {
  display: flex;
  gap: 8px;
  list-style: none;
}
.nav__link {
  display: inline-block;
  padding: 8px 16px;
  border-radius: 8px;
  color: var(--color-neutral-700);
  font-weight: 500;
  font-size: 15px;
}
.nav__link:hover { background: var(--color-primary-50); color: var(--color-primary-700); }
.nav__link.is-active { color: var(--color-primary-700); }
.nav__cta { margin-left: 16px; }
.nav__toggle {
  display: none;
  width: 40px;
  height: 40px;
  align-items: center;
  justify-content: center;
  border-radius: 8px;
}
.nav__toggle:hover { background: var(--color-neutral-100); }
.nav__toggle svg { width: 24px; height: 24px; stroke: var(--color-neutral-800); }

@media (max-width: 768px) {
  /* On mobile, the brand Chinese subtitle is hidden to save space */
  .nav__brand-zh { display: none; }

  /* Hidden by default on mobile */
  .nav__menu,
  .nav__cta,
  .nav .lang-switch { display: none; }

  /* Hamburger always visible on mobile, on top */
  .nav__toggle {
    display: flex;
    position: relative;
    z-index: 2;
  }

  /* When menu is open: convert nav to multi-row layout */
  .site-header.is-open {
    border-bottom-color: var(--color-neutral-200);
  }
  .site-header.is-open .nav {
    flex-wrap: wrap;
    height: auto;
    align-items: center;
    padding-block: 16px;
    gap: 0;
  }
  /* First row: brand left, toggle right.
     Use `order` because the toggle is the last child in HTML source order,
     and flex-wrap would otherwise push it to the bottom row. */
  .site-header.is-open .nav__brand  { flex: 1 1 auto;  order: 1; }
  .site-header.is-open .nav__toggle { flex: 0 0 auto;  order: 2; }

  /* Subsequent rows fill width */
  .site-header.is-open .nav__menu        { order: 3; }
  .site-header.is-open .nav__cta         { order: 4; }
  .site-header.is-open .nav .lang-switch { order: 5; }
  .site-header.is-open .nav__menu,
  .site-header.is-open .nav__cta,
  .site-header.is-open .nav .lang-switch {
    flex: 1 0 100%;
    margin: 0;
  }

  .site-header.is-open .nav__menu {
    display: flex;
    flex-direction: column;
    position: static;
    background: transparent;
    border: 0;
    padding: 0;
    margin-top: 16px;
    padding-top: 16px;
    border-top: 1px solid var(--color-neutral-200);
    gap: 2px;
  }
  .site-header.is-open .nav__menu .nav__link {
    padding: 12px 8px;
    font-size: 16px;
  }

  .site-header.is-open .nav__cta {
    display: inline-flex;
    align-self: flex-start;
    width: auto;
    margin-top: 12px;
  }

  .site-header.is-open .nav .lang-switch {
    display: block;
    margin-top: 12px;
    padding-top: 16px;
    border-top: 1px solid var(--color-neutral-200);
  }
  .site-header.is-open .nav .lang-switch__menu {
    position: static;
    box-shadow: none;
    border: 0;
    padding: 0;
    margin-top: 8px;
    background: transparent;
  }
  .site-header.is-open .nav .lang-switch__trigger {
    width: 100%;
    justify-content: space-between;
  }

  /* Animate hamburger to X icon on open */
  .site-header.is-open .nav__toggle svg path {
    transition: opacity 0.18s ease;
  }
  .site-header.is-open .nav__toggle svg {
    transform: rotate(90deg);
    transition: transform 0.18s ease;
  }
}

/* ---------- 7. Hero ---------- */
.hero {
  position: relative;
  padding-block: clamp(96px, 14vw, 180px) clamp(80px, 10vw, 140px);
  background: linear-gradient(135deg, var(--color-primary-900) 0%, var(--color-primary-700) 60%, var(--color-primary-500) 100%);
  color: #fff;
  overflow: hidden;
}
.hero__bg-svg {
  position: absolute;
  inset: 0;
  pointer-events: none;
  opacity: 0.4;
}
.hero__content {
  position: relative;
  z-index: 1;
  max-width: 820px;
}
.hero h1 { color: #fff; }
.hero h1 .accent {
  background: linear-gradient(135deg, var(--color-accent-300), var(--color-accent-500));
  background-clip: text;
  -webkit-background-clip: text;
  color: transparent;
}
.hero__sub {
  font-size: clamp(20px, 2.4vw, 28px);
  color: var(--color-primary-100);
  margin: 24px 0 12px;
  font-weight: 400;
}
.hero__lead {
  color: var(--color-primary-100);
  font-size: clamp(16px, 1.6vw, 18px);
  margin-bottom: 40px;
  max-width: 64ch;
}
.hero__actions { display: flex; flex-wrap: wrap; gap: 16px; }
.hero__meta {
  margin-top: 64px;
  display: flex;
  flex-wrap: wrap;
  gap: 32px 48px;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--color-primary-100);
}
.hero__meta span { display: flex; align-items: center; gap: 8px; }
.hero__meta strong { color: #fff; font-weight: 600; }

/* ---------- 8. Section · Services Cards ---------- */
.section--services { background: var(--color-neutral-0); }
.services__intro {
  text-align: center;
  max-width: 720px;
  margin: 0 auto 64px;
}
.service-card {
  position: relative;
  padding: 32px 28px 36px;
  background: var(--color-neutral-0);
  border: 1px solid var(--color-neutral-200);
  border-radius: var(--radius-lg);
  transition: all var(--t-base);
  overflow: hidden;
  display: flex;
  flex-direction: column;
}
.service-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--color-primary-200);
}
.service-card__icon {
  width: 56px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-primary-50);
  color: var(--color-primary-500);
  border-radius: 14px;
  margin-bottom: 24px;
}
.service-card__icon svg { width: 28px; height: 28px; }
.service-card h3 { margin-bottom: 8px; }
.service-card .tagline {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--color-primary-500);
  font-weight: 500;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  margin-bottom: 12px;
}
.service-card p { color: var(--color-neutral-600); font-size: 15px; }
.service-card__zh { color: var(--color-neutral-500); font-size: 13px; margin-top: 8px; }
.service-card__link {
  margin-top: auto;
  padding-top: 16px;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-weight: 600;
  font-size: 14px;
}
.service-card__link::after { content: "→"; transition: transform var(--t-base); }
.service-card:hover .service-card__link::after { transform: translateX(4px); }

/* ---------- 9. Section · Why Us ---------- */
.section--why { background: var(--color-primary-50); }
.why__grid { display: grid; grid-template-columns: 1fr; gap: 40px; align-items: center; }
@media (min-width: 900px) { .why__grid { grid-template-columns: 1fr 1fr; gap: 64px; } }
.why__points { list-style: none; display: grid; gap: 24px; }
.why__point {
  display: flex;
  gap: 16px;
  padding: 20px;
  background: rgba(255, 255, 255, 0.6);
  border-radius: var(--radius-md);
}
.why__point-num {
  font-family: var(--font-mono);
  color: var(--color-primary-500);
  font-weight: 600;
  font-size: 14px;
  flex-shrink: 0;
  margin-top: 4px;
}
.why__point h4 { margin-bottom: 4px; font-size: 16px; }
.why__point p { font-size: 14px; color: var(--color-neutral-600); margin: 0; }
.why__visual {
  border-radius: var(--radius-xl);
  overflow: hidden;
  aspect-ratio: 4/5;
  background: var(--color-primary-200);
}
.why__visual img { width: 100%; height: 100%; object-fit: cover; }

/* ---------- 10. Section · Services Detail ---------- */
.service-detail { padding-block: var(--section-py); border-top: 1px solid var(--color-neutral-200); }
.service-detail:first-of-type { border-top: 0; }
.service-detail__grid { display: grid; gap: 48px; align-items: center; }
@media (min-width: 900px) {
  .service-detail__grid { grid-template-columns: 1fr 1fr; gap: 80px; }
  .service-detail--reverse .service-detail__grid > :first-child { order: 2; }
}
.service-detail__visual {
  border-radius: var(--radius-xl);
  overflow: hidden;
  aspect-ratio: 4/3;
  background: var(--color-primary-100);
  position: relative;
}
.service-detail__visual img {
  width: 100%; height: 100%; object-fit: cover;
}
.service-detail__visual::after {
  content: '';
  position: absolute; inset: 0;
  background: linear-gradient(180deg, transparent 60%, rgba(10, 50, 102, 0.10));
}
.service-detail__capabilities { list-style: none; display: grid; gap: 12px; margin-top: 24px; }
.service-detail__capabilities li {
  display: flex; gap: 12px; align-items: flex-start;
  padding: 12px 16px;
  background: var(--color-primary-50);
  border-radius: var(--radius-sm);
  font-size: 14px;
  color: var(--color-neutral-700);
}
.service-detail__capabilities li::before {
  content: '✓';
  color: var(--color-primary-500);
  font-weight: 700;
  flex-shrink: 0;
}
.service-detail__markets { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 20px; }
.flag-pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  background: var(--color-neutral-0);
  border: 1px solid var(--color-neutral-200);
  border-radius: 999px;
  font-size: 13px;
  font-weight: 500;
  color: var(--color-neutral-700);
}

/* ---------- 11. CTA Banner ---------- */
.cta-banner {
  background: linear-gradient(135deg, var(--color-primary-700), var(--color-primary-900));
  color: #fff;
  border-radius: var(--radius-xl);
  padding: 64px clamp(32px, 6vw, 80px);
  text-align: center;
  position: relative;
  overflow: hidden;
}
.cta-banner__svg {
  position: absolute;
  inset: 0;
  opacity: 0.16;
  pointer-events: none;
}
.cta-banner h2 { color: #fff; max-width: 720px; margin: 0 auto 16px; }
.cta-banner p {
  color: var(--color-primary-100);
  max-width: 560px;
  margin: 0 auto 32px;
  font-size: 17px;
}
.cta-banner__actions { display: flex; flex-wrap: wrap; justify-content: center; gap: 16px; position: relative; }

/* ---------- 12. Footer ---------- */
.site-footer {
  background: var(--color-neutral-900);
  color: var(--color-neutral-300);
  padding-block: 64px 32px;
}
.footer__grid {
  display: grid;
  gap: 48px;
  grid-template-columns: 1.4fr repeat(4, 1fr);
}
@media (max-width: 900px) {
  .footer__grid { grid-template-columns: 1fr 1fr; gap: 40px 32px; }
  .footer__brand { grid-column: 1 / -1; }
}
.footer__brand .nav__brand { color: #fff; }
.footer__brand .nav__brand-zh { color: var(--color-neutral-400); }
.footer__brand p { color: var(--color-neutral-400); font-size: 14px; max-width: 280px; margin-top: 16px; }
.footer__col h5 {
  color: #fff;
  font-size: 13px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 16px;
}
.footer__col ul { list-style: none; display: grid; gap: 8px; }
.footer__col a {
  color: var(--color-neutral-400);
  font-size: 14px;
  transition: color var(--t-base);
}
.footer__col a:hover { color: #fff; }
.footer__bottom {
  margin-top: 64px;
  padding-top: 24px;
  border-top: 1px solid var(--color-neutral-700);
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 16px;
  font-size: 13px;
  color: var(--color-neutral-500);
}
.footer__bottom .reg-info code {
  font-family: var(--font-mono);
  color: var(--color-neutral-300);
  background: var(--color-neutral-800);
  padding: 2px 8px;
  border-radius: 4px;
  margin-right: 8px;
}

/* ---------- 13. Page-specific: About ---------- */
.page-hero {
  padding-block: clamp(80px, 10vw, 140px) clamp(56px, 8vw, 96px);
  background: linear-gradient(180deg, var(--color-primary-50), transparent);
}
.page-hero__content { max-width: 760px; }
.page-hero__lead { font-size: clamp(18px, 2vw, 22px); color: var(--color-neutral-600); }

.bilingual-block { display: grid; gap: 16px; }
.bilingual-block .en { font-size: 16px; }
.bilingual-block .zh { font-size: 15px; color: var(--color-neutral-600); padding-top: 16px; border-top: 1px solid var(--color-neutral-200); }

.values-grid { display: grid; gap: 24px; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); margin-top: 48px; }
.value-card {
  padding: 32px 28px;
  background: var(--color-neutral-0);
  border: 1px solid var(--color-neutral-200);
  border-radius: var(--radius-lg);
}
.value-card__num {
  font-family: var(--font-mono);
  color: var(--color-primary-500);
  font-size: 14px;
  font-weight: 600;
  margin-bottom: 16px;
}
.value-card h3 { font-size: 22px; margin-bottom: 12px; }
.value-card p { color: var(--color-neutral-600); font-size: 14px; line-height: 1.6; margin: 0; }

.stats-row { display: grid; grid-template-columns: repeat(auto-fit, minmax(140px, 1fr)); gap: 32px; margin: 64px 0; padding: 40px; background: var(--color-primary-50); border-radius: var(--radius-lg); }
.stat-item { text-align: center; }
.stat-item__num {
  font-family: var(--font-display);
  font-size: clamp(28px, 4vw, 40px);
  font-weight: 700;
  color: var(--color-primary-700);
  line-height: 1;
}
.stat-item__label {
  margin-top: 8px;
  font-size: 13px;
  color: var(--color-neutral-600);
  font-weight: 500;
}

/* ---------- 14. Page-specific: Contact ---------- */
.contact-grid { display: grid; gap: 40px; grid-template-columns: 1fr; }
@media (min-width: 900px) { .contact-grid { grid-template-columns: 1fr 1fr; } }
.contact-card {
  padding: 32px;
  background: var(--color-neutral-0);
  border: 1px solid var(--color-neutral-200);
  border-radius: var(--radius-lg);
}
.contact-card h3 { display: flex; align-items: center; gap: 12px; font-size: 18px; margin-bottom: 16px; }
.contact-card h3 svg { width: 22px; height: 22px; color: var(--color-primary-500); }
.contact-card a { font-size: 18px; font-weight: 600; word-break: break-all; }
.contact-card .meta { color: var(--color-neutral-500); font-size: 13px; margin-top: 8px; }
.contact-card address { font-style: normal; color: var(--color-neutral-700); line-height: 1.7; }

.reg-table { width: 100%; border-collapse: collapse; margin-top: 24px; }
.reg-table td {
  padding: 12px 16px;
  border-bottom: 1px solid var(--color-neutral-200);
  font-size: 14px;
  vertical-align: top;
}
.reg-table td:first-child { font-weight: 600; color: var(--color-neutral-600); width: 200px; }
.reg-table td:last-child { font-family: var(--font-mono); color: var(--color-neutral-800); }

/* ---------- 15. Legal pages ---------- */
.legal-page { padding-block: clamp(56px, 6vw, 96px); background: #fff; }
.legal-page .container { max-width: 800px; }
.legal-page h2 { margin-top: 56px; margin-bottom: 16px; font-size: 24px; padding-top: 8px; }
.legal-page h2:first-child { margin-top: 0; }
.legal-page h3 { font-size: 18px; margin-top: 32px; margin-bottom: 12px; }
.legal-page p { font-size: 15px; color: var(--color-neutral-700); margin-bottom: 16px; }
.legal-page ul, .legal-page ol { margin: 16px 0 24px; padding-left: 24px; color: var(--color-neutral-700); }
.legal-page li { margin-bottom: 8px; font-size: 15px; }
.legal-page .last-updated {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--color-neutral-500);
  background: var(--color-neutral-50);
  padding: 8px 16px;
  border-radius: 8px;
  display: inline-block;
  margin-bottom: 32px;
}
.legal-page details { margin: 16px 0; padding: 16px; background: var(--color-neutral-50); border-radius: 8px; }
.legal-page summary { cursor: pointer; font-weight: 600; }

/* ---------- 16. 404 ---------- */
.error-page {
  min-height: 60vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding-block: 96px;
}
.error-page__num {
  font-family: var(--font-display);
  font-size: clamp(96px, 18vw, 180px);
  font-weight: 700;
  background: linear-gradient(135deg, var(--color-primary-500), var(--color-accent-500));
  background-clip: text;
  -webkit-background-clip: text;
  color: transparent;
  line-height: 1;
}
.error-page h1 { margin: 24px 0 16px; }

/* ---------- 17. Utilities ---------- */
.text-center { text-align: center; }
.mt-0 { margin-top: 0 !important; }
.mt-32 { margin-top: 32px; }
.mb-0 { margin-bottom: 0 !important; }
.text-mono { font-family: var(--font-mono); }
.text-muted { color: var(--color-neutral-500); }

/* ---------- 17.5 Language Switcher ---------- */
.lang-switch {
  position: relative;
  margin-left: 8px;
}
.lang-switch__trigger {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 12px;
  border-radius: 8px;
  color: var(--color-neutral-700);
  font-weight: 500;
  font-size: 14px;
  cursor: pointer;
  border: 1px solid var(--color-neutral-200);
  background: transparent;
  transition: all var(--t-base);
}
.lang-switch__trigger:hover {
  background: var(--color-primary-50);
  color: var(--color-primary-700);
  border-color: var(--color-primary-200);
}
.lang-switch__trigger svg { width: 16px; height: 16px; flex-shrink: 0; }
.lang-switch__trigger .caret {
  width: 12px; height: 12px;
  transition: transform var(--t-fast);
}
.lang-switch.is-open .lang-switch__trigger .caret { transform: rotate(180deg); }
.lang-switch.is-open .lang-switch__trigger { background: var(--color-primary-50); }
.lang-switch__menu {
  position: absolute;
  top: calc(100% + 6px);
  right: 0;
  min-width: 160px;
  background: #fff;
  border: 1px solid var(--color-neutral-200);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-md);
  padding: 6px;
  display: none;
  z-index: 60;
}
.lang-switch.is-open .lang-switch__menu { display: block; }
.lang-switch__item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  padding: 10px 12px;
  border-radius: 6px;
  font-size: 14px;
  color: var(--color-neutral-700);
  cursor: pointer;
  background: transparent;
  border: 0;
  text-align: left;
}
.lang-switch__item:hover { background: var(--color-primary-50); color: var(--color-primary-700); }
.lang-switch__item.is-active { color: var(--color-primary-700); font-weight: 600; }
.lang-switch__item.is-active::after { content: '✓'; }
.lang-switch__item-zh {
  font-size: 12px;
  color: var(--color-neutral-500);
  margin-left: 6px;
}

/* Mobile lang-switch styling lives in the §6 Header media block */

/* ---------- 18. Animations (subtle) ---------- */
@media (prefers-reduced-motion: no-preference) {
  .reveal { opacity: 0; transform: translateY(16px); transition: opacity 0.6s ease, transform 0.6s ease; }
  .reveal.is-visible { opacity: 1; transform: none; }
}