:root {
  --orange: #f97316;
  --orange-dark: #ea580c;
  --teal: #0d9488;
  --teal-dark: #0f766e;
  --navy: #1e3a5f;
  --navy-dark: #152a45;
  --bg: #eef1f5;
  --card: #ffffff;
  --ink: #1a2332;
  --ink-muted: #5a6578;
  --border: #dde3ea;
  --shadow: 0 4px 24px rgba(30, 58, 95, 0.08);
  --stripe-w: 14px;
  --max: 1140px;
  --header-h: 64px;
  --font-sans: "Noto Sans SC", "Microsoft YaHei", sans-serif;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 20px);
}

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.82;
  color: var(--ink);
  background: var(--bg);
  min-height: 100vh;
}

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

a {
  color: var(--teal-dark);
  text-decoration: none;
  font-weight: 500;
}
a:hover { color: var(--orange-dark); text-decoration: underline; }

.container { width: min(100% - 2rem, var(--max)); margin-inline: auto; }

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 500;
  background: var(--card);
  border-bottom: 1px solid var(--border);
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.04);
}
.header-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: var(--header-h);
  gap: 1rem;
}
.brand {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  color: var(--navy);
  font-weight: 700;
  font-size: 1rem;
  text-decoration: none;
}
.brand:hover { color: var(--orange); text-decoration: none; }
.brand img { width: 38px; height: 38px; border-radius: 8px; }
.brand b { color: var(--orange); }

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 10px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--card);
  cursor: pointer;
}
.nav-toggle span {
  height: 2px;
  background: var(--navy);
  border-radius: 2px;
  transition: 0.25s;
}
.nav-toggle.is-open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.is-open span:nth-child(2) { opacity: 0; }
.nav-toggle.is-open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

.site-nav ul {
  display: flex;
  flex-wrap: wrap;
  gap: 0.2rem 1.5rem;
  list-style: none;
  margin: 0;
  padding: 0;
}
.site-nav a {
  color: var(--ink-muted);
  font-size: 0.9rem;
  font-weight: 500;
  text-decoration: none;
}
.site-nav a:hover,
.site-nav a.active { color: var(--orange); }

/* Ads */
.ads-top-bar {
  padding: 0.55rem 0;
  background: var(--card);
  border-bottom: 1px solid var(--border);
}
#ads {
  display: flex;
  justify-content: center;
  align-items: flex-start;
  flex-wrap: wrap;
  margin: 8px 0;
  gap: 0.5rem;
}
#ads > div,
#ads .ads-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  width: 70px;
}
#ads img {
  width: 65px;
  height: 65px;
  object-fit: cover;
  border-radius: 10px;
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
  transition: transform 180ms ease;
}
#ads a { display: inline-block; text-decoration: none; }
#ads img:hover { transform: translateY(-3px) scale(1.04); }
#ads figcaption,
#ads .caption {
  height: 15px;
  font-size: 11px;
  color: var(--ink-muted);
  text-align: center;
  max-width: 100px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  margin-top: 4px;
}
.applist-title {
  text-align: center;
  font-size: 0.82rem;
  color: var(--ink-muted);
  letter-spacing: 0.08em;
}

/* Hero */
.hero-block {
  padding: 2.5rem 0 1.5rem;
}
.hero-grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 2rem;
  align-items: center;
}
.hero-block h1 {
  font-size: clamp(1.5rem, 3.5vw, 2.1rem);
  line-height: 1.35;
  margin: 0 0 1rem;
  color: var(--navy);
}
.hero-block .lead {
  font-size: 1rem;
  color: var(--ink-muted);
  margin: 0;
}
.hero-visual img {
  border-radius: 12px;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
}

/* Link strip */
.link-strip {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.65rem 1rem;
  padding: 1rem 0 1.5rem;
}
.link-strip a {
  padding: 0.5rem 1.1rem;
  border-radius: 999px;
  background: var(--card);
  border: 2px solid var(--border);
  color: var(--navy);
  font-size: 0.88rem;
  font-weight: 600;
  text-decoration: none;
  box-shadow: var(--shadow);
  transition: border-color 0.2s, color 0.2s;
}
.link-strip a:hover {
  border-color: var(--orange);
  color: var(--orange);
  text-decoration: none;
}

/* Stripe accordion */
.accordion-wrap {
  padding: 0 0 3rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.stripe-panel {
  display: flex;
  border-radius: 12px;
  overflow: hidden;
  box-shadow: var(--shadow);
  background: var(--card);
}

.stripe-panel .stripe {
  flex-shrink: 0;
  width: var(--stripe-w);
}

.stripe-panel[data-stripe="orange"] .stripe { background: var(--orange); }
.stripe-panel[data-stripe="teal"] .stripe { background: var(--teal); }
.stripe-panel[data-stripe="navy"] .stripe { background: var(--navy); }

.stripe-panel[data-stripe="orange"] .accordion-head { border-left-color: var(--orange); }
.stripe-panel[data-stripe="teal"] .accordion-head { border-left-color: var(--teal); }
.stripe-panel[data-stripe="navy"] .accordion-head { border-left-color: var(--navy); }

.panel-inner { flex: 1; min-width: 0; }

.accordion-head {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 1.15rem 1.5rem;
  border: none;
  border-left: 4px solid transparent;
  background: var(--card);
  cursor: pointer;
  text-align: left;
  font-family: inherit;
  transition: background 0.2s;
}
.accordion-head:hover { background: #fafbfc; }

.accordion-head .head-text h2 {
  margin: 0;
  font-size: 1.15rem;
  color: var(--navy);
  line-height: 1.35;
}
.accordion-head .head-text .tag {
  display: inline-block;
  margin-top: 0.25rem;
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink-muted);
}

.accordion-icon {
  flex-shrink: 0;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  border: 2px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  color: var(--ink-muted);
  transition: transform 0.3s, background 0.2s;
}
.stripe-panel.is-open .accordion-icon {
  transform: rotate(45deg);
  background: var(--bg);
}

.accordion-body {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.45s ease;
}
.stripe-panel.is-open .accordion-body { max-height: 8000px; }

.accordion-content {
  padding: 0 1.5rem 1.75rem;
  color: var(--ink-muted);
}
.accordion-content p { margin: 0 0 1rem; text-align: justify; }
.accordion-content strong { color: var(--ink); }
.accordion-content h3 {
  font-size: 1.05rem;
  color: var(--navy);
  margin: 1.25rem 0 0.65rem;
}

.content-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
  align-items: start;
}

.feature-img {
  border-radius: 10px;
  overflow: hidden;
  border: 1px solid var(--border);
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.05);
}

.img-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.85rem;
  margin: 1.25rem 0;
}

.callout {
  padding: 1rem 1.25rem;
  border-radius: 8px;
  background: #f0fdfa;
  border-left: 4px solid var(--teal);
  font-size: 0.92rem;
  color: var(--ink);
  margin: 1rem 0;
}

/* Subpages */
.page-hero {
  padding: 2rem 0;
  background: var(--card);
  border-bottom: 1px solid var(--border);
  margin-bottom: 1.5rem;
}
.page-hero h1 {
  margin: 0.5rem 0 0;
  font-size: 1.75rem;
  color: var(--navy);
}
.breadcrumb {
  font-size: 0.85rem;
  color: var(--ink-muted);
}
.breadcrumb a { color: var(--ink-muted); text-decoration: none; }
.breadcrumb a:hover { color: var(--orange); }

.prose-card {
  background: var(--card);
  border-radius: 12px;
  padding: 2rem 1.75rem;
  box-shadow: var(--shadow);
  border-left: var(--stripe-w) solid var(--teal);
  margin-bottom: 2rem;
}
.prose-card p { margin: 0 0 1rem; color: var(--ink-muted); }
.prose-card strong { color: var(--ink); }
.prose-card h2 {
  font-size: 1.15rem;
  color: var(--navy);
  margin: 1.5rem 0 0.75rem;
}

.related-read {
  margin-top: 2rem;
  padding: 1.25rem 1.5rem;
  border-radius: 10px;
  background: var(--card);
  border-left: var(--stripe-w) solid var(--orange);
  box-shadow: var(--shadow);
}
.related-read h2 {
  font-size: 0.9rem;
  color: var(--navy);
  letter-spacing: 0.06em;
  margin: 0 0 0.75rem;
}
.related-read ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.5rem;
}
.related-read a { font-size: 0.9rem; }

.error-wrap { text-align: center; padding: 4rem 0; }
.error-wrap .code {
  font-size: 4rem;
  color: var(--orange);
  margin: 0;
  font-weight: 700;
}

.site-footer {
  margin-top: 1rem;
  padding: 2rem 0;
  border-top: 1px solid var(--border);
  font-size: 0.85rem;
  color: var(--ink-muted);
  background: var(--card);
}
.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem 2rem;
  margin-bottom: 1rem;
}
.footer-links a { color: var(--ink-muted); text-decoration: none; }
.footer-links a:hover { color: var(--orange); }

@media (max-width: 900px) {
  .hero-grid,
  .content-grid { grid-template-columns: 1fr; }
  .img-row { grid-template-columns: 1fr; }
}
@media (max-width: 768px) {
  .nav-toggle { display: flex; }
  .site-nav {
    position: fixed;
    inset: var(--header-h) 0 auto 0;
    background: var(--card);
    border-bottom: 1px solid var(--border);
    padding: 1rem;
    transform: translateY(-120%);
    opacity: 0;
    visibility: hidden;
    transition: 0.3s;
    box-shadow: 0 12px 32px rgba(0, 0, 0, 0.1);
  }
  .site-nav.is-open { transform: translateY(0); opacity: 1; visibility: visible; }
  .site-nav ul { flex-direction: column; }
  .site-nav a { display: block; padding: 0.65rem 0; border-bottom: 1px solid var(--border); }
  #ads {
    flex-wrap: nowrap;
    overflow-x: auto;
    scroll-snap-type: x proximity;
    justify-content: flex-start;
  }
  #ads > div,
  #ads .ads-item { width: 84px; flex-shrink: 0; scroll-snap-align: center; }
}