:root {
  color-scheme: light dark;
  --bg-top: #0a1628;
  --bg-bottom: #0f2847;
  --card: rgba(255, 255, 255, 0.08);
  --card-hover: rgba(255, 255, 255, 0.12);
  --card-solid: #ffffff;
  --text: #f0f4ff;
  --text-body: #c8d4e8;
  --muted: #8fa3bf;
  --accent: #4dabff;
  --accent-2: #00d4aa;
  --accent-glow: rgba(77, 171, 255, 0.35);
  --border: rgba(255, 255, 255, 0.12);
  --nav-bg: rgba(10, 22, 40, 0.72);
  --shadow: 0 24px 64px rgba(0, 0, 0, 0.35);
  --radius: 20px;
  --radius-sm: 12px;
  --max: 920px;
}

@media (prefers-color-scheme: light) {
  :root {
    --bg-top: #e8f2ff;
    --bg-bottom: #f5f9ff;
    --card: rgba(255, 255, 255, 0.85);
    --card-hover: #ffffff;
    --card-solid: #ffffff;
    --text: #0a1628;
    --text-body: #334155;
    --muted: #64748b;
    --accent: #0071e3;
    --accent-2: #059669;
    --accent-glow: rgba(0, 113, 227, 0.2);
    --border: rgba(15, 23, 42, 0.08);
    --nav-bg: rgba(255, 255, 255, 0.82);
    --shadow: 0 20px 50px rgba(15, 23, 42, 0.08);
  }
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "Segoe UI", Roboto,
    "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background: linear-gradient(165deg, var(--bg-top) 0%, var(--bg-bottom) 55%, var(--bg-top) 100%);
  color: var(--text-body);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  background:
    radial-gradient(circle at 15% 10%, var(--accent-glow) 0%, transparent 42%),
    radial-gradient(circle at 85% 80%, rgba(0, 212, 170, 0.12) 0%, transparent 40%);
  z-index: 0;
}

a {
  color: var(--accent);
  text-decoration: none;
  transition: opacity 0.2s ease;
}

a:hover {
  opacity: 0.85;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(18px) saturate(160%);
  -webkit-backdrop-filter: blur(18px) saturate(160%);
  background: var(--nav-bg);
  border-bottom: 1px solid var(--border);
}

.site-header-inner {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0.85rem 1.25rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  color: var(--text);
  text-decoration: none;
  font-weight: 700;
  font-size: 1.05rem;
  letter-spacing: -0.02em;
}

.brand:hover {
  opacity: 1;
}

.brand-icon {
  width: 40px;
  height: 40px;
  border-radius: 11px;
  background: linear-gradient(135deg, #0071e3 0%, #00a8ff 50%, #00d4aa 100%);
  display: grid;
  place-items: center;
  box-shadow: 0 8px 24px var(--accent-glow);
  flex-shrink: 0;
}

.brand-icon svg {
  width: 22px;
  height: 22px;
  fill: white;
}

.site-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}

.site-nav a {
  padding: 0.45rem 0.85rem;
  border-radius: 999px;
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--muted);
  text-decoration: none;
  border: 1px solid transparent;
  transition: all 0.2s ease;
}

.site-nav a:hover,
.site-nav a.active {
  color: var(--text);
  background: var(--card);
  border-color: var(--border);
  opacity: 1;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.lang-switcher-wrap {
  display: flex;
  align-items: center;
  gap: 0.45rem;
}

.lang-switcher-wrap label {
  font-size: 0.82rem;
  color: var(--muted);
  white-space: nowrap;
}

.lang-switcher-wrap select {
  appearance: none;
  -webkit-appearance: none;
  padding: 0.4rem 1.75rem 0.4rem 0.65rem;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--card) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%238fa3bf' d='M2 4l4 4 4-4'/%3E%3C/svg%3E") no-repeat right 0.55rem center;
  color: var(--text);
  font-size: 0.82rem;
  font-family: inherit;
  cursor: pointer;
}

.lang-switcher-wrap select:focus {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.page-wrap {
  position: relative;
  z-index: 1;
  max-width: var(--max);
  margin: 0 auto;
  padding: 2.5rem 1.25rem 4rem;
}

.page-hero {
  text-align: center;
  margin-bottom: 2.5rem;
  animation: fadeUp 0.6s ease both;
}

.page-hero .eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.35rem 0.9rem;
  border-radius: 999px;
  background: var(--card);
  border: 1px solid var(--border);
  color: var(--accent);
  font-size: 0.82rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  margin-bottom: 1rem;
}

.page-hero h1 {
  margin: 0 0 0.75rem;
  font-size: clamp(1.85rem, 5vw, 2.75rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.15;
  color: var(--text);
}

.page-hero .subtitle {
  margin: 0 auto;
  max-width: 36rem;
  font-size: 1.05rem;
  color: var(--muted);
}

.meta-date {
  display: inline-block;
  margin-bottom: 1.5rem;
  padding: 0.35rem 0.75rem;
  border-radius: 999px;
  background: var(--card);
  border: 1px solid var(--border);
  color: var(--muted);
  font-size: 0.85rem;
}

.card {
  background: var(--card);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.6rem 1.75rem;
  margin-bottom: 1rem;
  box-shadow: var(--shadow);
  transition: transform 0.25s ease, background 0.25s ease;
  animation: fadeUp 0.6s ease both;
}

.card:hover {
  transform: translateY(-2px);
  background: var(--card-hover);
}

.card h2 {
  margin: 0 0 0.85rem;
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text);
  display: flex;
  align-items: center;
  gap: 0.55rem;
}

.card h3 {
  margin: 1.25rem 0 0.5rem;
  font-size: 1rem;
  font-weight: 650;
  color: var(--text);
}

.card h3:first-of-type {
  margin-top: 0;
}

.card p {
  margin: 0 0 0.85rem;
}

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

.card ul,
.card ol {
  margin: 0 0 0.85rem;
  padding-left: 1.35rem;
}

.card li {
  margin-bottom: 0.35rem;
}

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

.card strong {
  color: var(--text);
}

.section-icon {
  width: 28px;
  height: 28px;
  border-radius: 8px;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  display: inline-grid;
  place-items: center;
  flex-shrink: 0;
  font-size: 0.85rem;
}

.feature-grid {
  display: grid;
  gap: 1rem;
  margin-bottom: 1rem;
}

@media (min-width: 640px) {
  .feature-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

.feature-card {
  animation-delay: calc(var(--i, 0) * 0.08s);
}

.feature-card .section-icon {
  margin-bottom: 0.75rem;
}

.feature-card h2 {
  display: block;
  font-size: 1.1rem;
}

.feature-card p {
  font-size: 0.95rem;
  color: var(--muted);
}

.cta-banner {
  text-align: center;
  padding: 2rem 1.5rem;
  background: linear-gradient(135deg, rgba(0, 113, 227, 0.18), rgba(0, 212, 170, 0.12));
  border: 1px solid var(--border);
}

.cta-banner h2 {
  justify-content: center;
  display: block;
  margin-bottom: 0.5rem;
}

.contact-card {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 0.75rem;
}

.contact-email {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  padding: 0.75rem 1.25rem;
  border-radius: 999px;
  background: linear-gradient(135deg, var(--accent), #00a8ff);
  color: #fff !important;
  font-weight: 600;
  font-size: 0.95rem;
  box-shadow: 0 10px 30px var(--accent-glow);
  opacity: 1;
}

.contact-email:hover {
  opacity: 0.92;
  transform: translateY(-1px);
}

.lang-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
}

.lang-tags span {
  padding: 0.3rem 0.7rem;
  border-radius: 999px;
  background: var(--card);
  border: 1px solid var(--border);
  font-size: 0.85rem;
  color: var(--text);
}

.faq-item + .faq-item {
  margin-top: 1.25rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--border);
}

.notice {
  padding: 1rem 1.15rem;
  border-radius: var(--radius-sm);
  background: rgba(77, 171, 255, 0.1);
  border: 1px solid rgba(77, 171, 255, 0.25);
  margin-bottom: 0.85rem;
}

.notice strong {
  color: var(--accent);
}

.site-footer {
  position: relative;
  z-index: 1;
  text-align: center;
  padding: 1.5rem 1.25rem 2.5rem;
  color: var(--muted);
  font-size: 0.85rem;
  border-top: 1px solid var(--border);
}

.site-footer a {
  color: var(--muted);
}

.site-footer a:hover {
  color: var(--accent);
}

@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(16px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (max-width: 640px) {
  .site-header-inner {
    justify-content: center;
  }

  .header-actions {
    width: 100%;
    justify-content: center;
  }

  .site-nav {
    justify-content: center;
    width: 100%;
  }

  .card {
    padding: 1.25rem 1.15rem;
  }
}