:root {
  --c-bg: #f5f7fb;
  --c-bg-soft: #eef2f9;
  --c-surface: #ffffff;
  --c-surface-glass: rgba(255, 255, 255, 0.72);
  --c-border: rgba(26, 43, 76, 0.10);
  --c-text: #1c2536;
  --c-text-soft: #4a5568;
  --c-text-muted: #6b7688;
  --c-primary: #1a2b4c;
  --c-primary-soft: #2c4370;
  --c-accent: #f2b134;
  --c-accent-2: #e86a5b;
  --c-accent-3: #4fa3a5;
  --c-link: #2b5aa8;
  --grad-hero: linear-gradient(135deg, #1a2b4c 0%, #2c4370 42%, #3a5a8c 68%, #4fa3a5 100%);
  --grad-btn: linear-gradient(135deg, #f2b134 0%, #e86a5b 100%);
  --grad-btn-2: linear-gradient(135deg, #4fa3a5 0%, #2c4370 100%);
  --shadow-sm: 0 2px 8px rgba(26, 43, 76, 0.06);
  --shadow-md: 0 10px 30px rgba(26, 43, 76, 0.10);
  --shadow-lg: 0 20px 50px rgba(26, 43, 76, 0.16);
  --radius-sm: 10px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-pill: 999px;
  --space-xs: 8px;
  --space-sm: 12px;
  --space-md: 20px;
  --space-lg: 32px;
  --space-xl: 56px;
  --maxw: 1180px;
  --header-h: 72px;
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
  --font-sans: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", "Helvetica Neue", Arial, sans-serif;
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root {
    --c-bg: #0d1420;
    --c-bg-soft: #111a29;
    --c-surface: #16202f;
    --c-surface-glass: rgba(22, 32, 47, 0.72);
    --c-border: rgba(255, 255, 255, 0.10);
    --c-text: #e8edf6;
    --c-text-soft: #b8c3d4;
    --c-text-muted: #8a97ab;
    --c-primary: #2c4370;
    --c-primary-soft: #3a5a8c;
    --c-link: #7fb0f0;
    --grad-hero: linear-gradient(135deg, #0d1420 0%, #1a2b4c 45%, #2c4370 75%, #356f72 100%);
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.35);
    --shadow-md: 0 10px 30px rgba(0, 0, 0, 0.45);
    --shadow-lg: 0 20px 50px rgba(0, 0, 0, 0.55);
    color-scheme: dark;
  }
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 16px);
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.75;
  color: var(--c-text);
  background-color: var(--c-bg);
  background-image:
    radial-gradient(circle at 12% 0%, rgba(79, 163, 165, 0.10), transparent 42%),
    radial-gradient(circle at 88% 8%, rgba(242, 177, 52, 0.10), transparent 40%);
  background-attachment: fixed;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

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

a {
  color: var(--c-link);
  text-decoration: none;
  transition: color 0.25s var(--ease), opacity 0.25s var(--ease);
}

a:hover {
  color: var(--c-accent-2);
}

h1, h2, h3, h4 {
  line-height: 1.35;
  color: var(--c-text);
  font-weight: 700;
  letter-spacing: 0.01em;
}

h1 { font-size: clamp(1.7rem, 4.2vw, 2.6rem); }
h2 { font-size: clamp(1.4rem, 3vw, 2rem); }
h3 { font-size: clamp(1.1rem, 2.2vw, 1.35rem); }
h4 { font-size: 1.05rem; }

p {
  margin: 0 0 1em;
  color: var(--c-text-soft);
}

ul, ol {
  padding-left: 1.35em;
  color: var(--c-text-soft);
}

li {
  margin-bottom: 0.4em;
}

blockquote {
  margin: 1em 0;
  padding: 16px 20px;
  border-left: 4px solid var(--c-accent);
  background: var(--c-surface-glass);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  box-shadow: var(--shadow-sm);
}

blockquote p {
  margin: 0;
  color: var(--c-text);
  font-style: italic;
}

.visually-hidden {
  position: absolute !important;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

/* ============ Header ============ */
#site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--c-surface-glass);
  backdrop-filter: blur(18px) saturate(160%);
  -webkit-backdrop-filter: blur(18px) saturate(160%);
  border-bottom: 1px solid var(--c-border);
  box-shadow: 0 4px 24px rgba(26, 43, 76, 0.06);
}

.header-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 var(--space-md);
  min-height: var(--header-h);
  display: flex;
  align-items: center;
  gap: var(--space-md);
  flex-wrap: wrap;
}

.logo {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  font-size: 1.15rem;
  color: var(--c-text);
  letter-spacing: 0.02em;
  flex-shrink: 0;
}

.logo svg {
  border-radius: 10px;
  box-shadow: var(--shadow-sm);
  transition: transform 0.4s var(--ease), box-shadow 0.4s var(--ease);
}

.logo:hover svg {
  transform: rotate(-6deg) scale(1.06);
  box-shadow: var(--shadow-md);
}

.logo span {
  background: linear-gradient(120deg, var(--c-primary) 0%, var(--c-accent-3) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

#site-header nav {
  flex: 1 1 auto;
}

.nav-list {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  margin: 0;
  padding: 0;
}

.nav-list li {
  margin: 0;
}

.nav-list a {
  display: inline-block;
  padding: 7px 12px;
  border-radius: var(--radius-pill);
  font-size: 0.9rem;
  color: var(--c-text-soft);
  font-weight: 500;
  position: relative;
  transition: color 0.25s var(--ease), background-color 0.25s var(--ease), transform 0.25s var(--ease);
}

.nav-list a:hover,
.nav-list a:focus-visible {
  color: var(--c-primary);
  background: rgba(79, 163, 165, 0.12);
  transform: translateY(-1px);
}

.site-search {
  display: flex;
  align-items: center;
  gap: 0;
  background: var(--c-bg-soft);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-pill);
  padding: 4px;
  transition: border-color 0.25s var(--ease), box-shadow 0.25s var(--ease);
}

.site-search:focus-within {
  border-color: var(--c-accent-3);
  box-shadow: 0 0 0 3px rgba(79, 163, 165, 0.18);
}

.site-search input[type="search"] {
  border: 0;
  background: transparent;
  color: var(--c-text);
  font-family: inherit;
  font-size: 0.9rem;
  padding: 6px 12px;
  min-width: 150px;
  outline: none;
  border-radius: var(--radius-pill);
}

.site-search input::placeholder {
  color: var(--c-text-muted);
}

.site-search button {
  border: 0;
  cursor: pointer;
  font-family: inherit;
  font-size: 0.85rem;
  font-weight: 600;
  color: #fff;
  background: var(--grad-btn-2);
  padding: 7px 16px;
  border-radius: var(--radius-pill);
  transition: filter 0.25s var(--ease), transform 0.25s var(--ease);
}

.site-search button:hover {
  filter: brightness(1.1);
  transform: translateY(-1px);
}

/* ============ Main layout ============ */
main {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 var(--space-md) var(--space-xl);
}

main > section {
  margin-top: var(--space-xl);
  padding: var(--space-lg);
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  animation: fadeUp 0.7s var(--ease) both;
  animation-timeline: view();
  animation-range: entry 0% entry 60%;
}

@supports not (animation-timeline: view()) {
  main > section {
    animation: none;
    opacity: 1;
    transform: none;
  }
}

@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(28px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }
}

/* ============ Hero ============ */
#hero {
  margin-top: var(--space-md);
  padding: 0;
  border: 0;
  background: transparent;
  box-shadow: none;
  overflow: hidden;
}

.hero-inner {
  position: relative;
  padding: clamp(32px, 6vw, 72px) clamp(22px, 5vw, 64px);
  border-radius: var(--radius-lg);
  background: var(--grad-hero);
  color: #f4f7ff;
  box-shadow: var(--shadow-lg);
  overflow: hidden;
  isolation: isolate;
}

.hero-inner::before,
.hero-inner::after {
  content: "";
  position: absolute;
  border-radius: 50%;
  filter: blur(60px);
  opacity: 0.55;
  z-index: -1;
  pointer-events: none;
}

.hero-inner::before {
  width: 420px;
  height: 420px;
  top: -160px;
  right: -120px;
  background: radial-gradient(circle, rgba(242, 177, 52, 0.65), transparent 70%);
  animation: floatA 14s ease-in-out infinite alternate;
}

.hero-inner::after {
  width: 380px;
  height: 380px;
  bottom: -180px;
  left: -100px;
  background: radial-gradient(circle, rgba(79, 163, 165, 0.65), transparent 70%);
  animation: floatB 18s ease-in-out infinite alternate;
}

@keyframes floatA {
  from { transform: translate3d(0, 0, 0) scale(1); }
  to { transform: translate3d(-40px, 30px, 0) scale(1.12); }
}

@keyframes floatB {
  from { transform: translate3d(0, 0, 0) scale(1); }
  to { transform: translate3d(40px, -30px, 0) scale(1.10); }
}

#hero-title {
  color: #ffffff;
  margin: 0 0 var(--space-md);
  text-shadow: 0 2px 18px rgba(0, 0, 0, 0.25);
  letter-spacing: 0.015em;
}

.hero-lead {
  color: rgba(244, 247, 255, 0.88);
  font-size: clamp(0.95rem, 1.6vw, 1.05rem);
  max-width: 78ch;
  margin-bottom: 1em;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
  margin: var(--space-lg) 0 var(--space-lg);
}

.btn-primary,
.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 13px 30px;
  border-radius: var(--radius-pill);
  font-weight: 700;
  font-size: 0.95rem;
  letter-spacing: 0.02em;
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease), filter 0.3s var(--ease);
  will-change: transform;
}

.btn-primary {
  color: #1a2b4c;
  background: var(--grad-btn);
  box-shadow: 0 8px 24px rgba(242, 177, 52, 0.35);
}

.btn-primary:hover {
  color: #1a2b4c;
  transform: translateY(-3px);
  box-shadow: 0 14px 34px rgba(232, 106, 91, 0.42);
  filter: brightness(1.05);
}

.btn-secondary {
  color: #ffffff;
  background: rgba(255, 255, 255, 0.14);
  border: 1px solid rgba(255, 255, 255, 0.35);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}

.btn-secondary:hover {
  color: #ffffff;
  background: rgba(255, 255, 255, 0.24);
  transform: translateY(-3px);
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.25);
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-sm);
  margin-top: var(--space-md);
}

.stat-item {
  padding: 18px 12px;
  text-align: center;
  border-radius: var(--radius-md);
  background: rgba(255, 255, 255, 0.10);
  border: 1px solid rgba(255, 255, 255, 0.18);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  transition: transform 0.35s var(--ease), background-color 0.35s var(--ease);
}

.stat-item:hover {
  transform: translateY(-4px);
  background: rgba(255, 255, 255, 0.18);
}

.stat-num {
  display: block;
  font-size: clamp(1.4rem, 3vw, 2rem);
  font-weight: 800;
  color: #ffffff;
  line-height: 1.2;
  letter-spacing: 0.02em;
}

.stat-num::after {
  content: "+";
  font-size: 0.65em;
  color: var(--c-accent);
  margin-left: 2px;
}

.stat-label {
  display: block;
  margin-top: 4px;
  font-size: 0.8rem;
  color: rgba(244, 247, 255, 0.78);
  letter-spacing: 0.04em;
}

/* ============ Breadcrumb ============ */
main > nav[aria-label="面包屑导航"] {
  margin-top: var(--space-md);
  animation: none;
}

.breadcrumb {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 0;
  padding: 10px 18px;
  font-size: 0.85rem;
  color: var(--c-text-muted);
  background: var(--c-surface-glass);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-pill);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  width: fit-content;
  box-shadow: var(--shadow-sm);
}

.breadcrumb li {
  margin: 0;
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.breadcrumb li + li::before {
  content: "›";
  color: var(--c-accent-3);
  font-weight: 700;
}

.breadcrumb a {
  color: var(--c-text-soft);
}

.breadcrumb a:hover {
  color: var(--c-accent-2);
}

/* ============ Section headings ============ */
main > section > h2 {
  position: relative;
  margin: 0 0 var(--space-md);
  padding-bottom: 14px;
}

main > section > h2::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 64px;
  height: 4px;
  border-radius: var(--radius-pill);
  background: var(--grad-btn);
}

main > section > h3 {
  margin-top: var(--space-lg);
  margin-bottom: var(--space-sm);
  color: var(--c-primary);
}

main > section > h3::before {
  content: "";
  display: inline-block;
  width: 6px;
  height: 0.95em;
  margin-right: 10px;
  vertical-align: -0.08em;
  border-radius: 3px;
  background: linear-gradient(180deg, var(--c-accent-3), var(--c-accent));
}

/* ============ Timeline ============ */
.timeline {
  list-style: none;
  padding: 0;
  margin: var(--space-md) 0;
  position: relative;
}

.timeline::before {
  content: "";
  position: absolute;
  left: 9px;
  top: 6px;
  bottom: 6px;
  width: 2px;
  background: linear-gradient(180deg, var(--c-accent-3), var(--c-accent), transparent);
  border-radius: 2px;
}

.timeline li {
  position: relative;
  padding: 10px 16px 10px 34px;
  margin: 0 0 10px;
  background: var(--c-bg-soft);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-sm);
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease);
}

.timeline li::before {
  content: "";
  position: absolute;
  left: 4px;
  top: 18px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--c-accent-3);
  box-shadow: 0 0 0 4px rgba(79, 163, 165, 0.18);
}

.timeline li:hover {
  transform: translateX(6px);
  box-shadow: var(--shadow-sm);
}

.timeline strong {
  color: var(--c-primary);
}

/* ============ Articles / News cards ============ */
#news article,
#articles article {
  position: relative;
  margin: 0 0 var(--space-md);
  padding: var(--space-md);
  background: var(--c-bg-soft);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-md);
  transition: transform 0.35s var(--ease), box-shadow 0.35s var(--ease), border-color 0.35s var(--ease), background-color 0.35s var(--ease);
}

#news article::before,
#articles article::before {
  content: "";
  position: absolute;
  left: 0;
  top: 16px;
  bottom: 16px;
  width: 4px;
  border-radius: var(--radius-pill);
  background: var(--grad-btn-2);
  opacity: 0;
  transition: opacity 0.35s var(--ease);
}

#news article:hover,
#articles article:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: rgba(79, 163, 165, 0.4);
  background: var(--c-surface);
}

#news article:hover::before,
#articles article:hover::before {
  opacity: 1;
}

#news h3,
#articles h3 {
  margin: 0 0 8px;
  font-size: 1.08rem;
  color: var(--c-primary);
  transition: color 0.3s var(--ease);
}

#news article:hover h3,
#articles article:hover h3 {
  color: var(--c-accent-2);
}

.meta {
  font-size: 0.8rem;
  color: var(--c-text-muted);
  letter-spacing: 0.03em;
  margin-bottom: 10px;
}

#news article a,
#articles article a {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--c-accent-3);
}

#news article a::after,
#articles article a::after {
  content: "→";
  transition: transform 0.3s var(--ease);
}

#news article a:hover::after,
#articles article a:hover::after {
  transform: translateX(4px);
}

/* ============ FAQ ============ */
#faq details {
  margin-bottom: var(--space-sm);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-md);
  background: var(--c-bg-soft);
  overflow: hidden;
  transition: box-shadow 0.3s var(--ease), border-color 0.3s var(--ease), background-color 0.3s var(--ease);
}

#faq details[open] {
  background: var(--c-surface);
  border-color: rgba(79, 163, 165, 0.45);
  box-shadow: var(--shadow-sm);
}

#faq summary {
  cursor: pointer;
  list-style: none;
  padding: 16px 48px 16px 20px;
  font-weight: 600;
  color: var(--c-text);
  position: relative;
  transition: color 0.25s var(--ease);
  user-select: none;
}

#faq summary::-webkit-details-marker {
  display: none;
}

#faq summary::after {
  content: "+";
  position: absolute;
  right: 18px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 1.4rem;
  font-weight: 400;
  line-height: 1;
  color: var(--c-accent-3);
  transition: transform 0.35s var(--ease), color 0.35s var(--ease);
}

#faq details[open] summary::after {
  content: "−";
  transform: translateY(-50%) rotate(180deg);
  color: var(--c-accent-2);
}

#faq summary:hover {
  color: var(--c-accent-2);
}

#faq details p {
  margin: 0;
  padding: 0 20px 18px;
  font-size: 0.94rem;
  color: var(--c-text-soft);
  animation: fadeIn 0.4s var(--ease);
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(-6px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ============ Sitemap / links ============ */
.sitemap-list,
.friend-links {
  list-style: none;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 10px;
}

.sitemap-list li,
.friend-links li {
  margin: 0;
}

.sitemap-list a,
.friend-links a {
  display: block;
  padding: 12px 16px;
  font-size: 0.9rem;
  color: var(--c-text-soft);
  background: var(--c-bg-soft);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-sm);
  transition: transform 0.3s var(--ease), color 0.3s var(--ease), border-color 0.3s var(--ease), background-color 0.3s var(--ease), box-shadow 0.3s var(--ease);
}

.sitemap-list a:hover,
.friend-links a:hover {
  color: #ffffff;
  background: var(--grad-btn-2);
  border-color: transparent;
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
}

/* ============ Contact & legal ============ */
#contact ul {
  list-style: none;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 10px;
}

#contact ul li {
  margin: 0;
  padding: 12px 16px;
  background: var(--c-bg-soft);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-sm);
  font-size: 0.92rem;
  transition: border-color 0.3s var(--ease), transform 0.3s var(--ease);
}

#contact ul li:hover {
  border-color: var(--c-accent-3);
  transform: translateY(-2px);
}

.update-info {
  margin-top: var(--space-md);
  font-size: 0.82rem;
  color: var(--c-text-muted);
  padding-top: var(--space-sm);
  border-top: 1px dashed var(--c-border);
}

/* ============ Footer ============ */
#site-footer {
  margin-top: var(--space-xl);
  background: linear-gradient(160deg, #1a2b4c 0%, #22375c 55%, #2c4370 100%);
  color: rgba(232, 237, 246, 0.82);
  padding: var(--space-xl) var(--space-md);
  position: relative;
  overflow: hidden;
}

#site-footer::before {
  content: "";
  position: absolute;
  top: -120px;
  right: -80px;
  width: 320px;
  height: 320px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(242, 177, 52, 0.28), transparent 70%);
  filter: blur(40px);
  pointer-events: none;
}

#site-footer::after {
  content: "";
  position: absolute;
  bottom: -140px;
  left: -60px;
  width: 300px;
  height: 300px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(79, 163, 165, 0.30), transparent 70%);
  filter: blur(40px);
  pointer-events: none;
}

.footer-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  position: relative;
  z-index: 1;
  text-align: center;
}

.footer-inner p {
  margin: 0 0 10px;
  color: rgba(232, 237, 246, 0.78);
  font-size: 0.9rem;
}

.footer-inner p:first-child {
  font-size: 1rem;
  font-weight: 700;
  color: #ffffff;
  letter-spacing: 0.03em;
}

.footer-inner a {
  color: var(--c-accent);
  margin: 0 4px;
}

.footer-inner a:hover {
  color: #ffffff;
  text-decoration: underline;
  text-underline-offset: 4px;
}

/* ============ Back to top ============ */
#back-to-top {
  position: fixed;
  right: 22px;
  bottom: 26px;
  z-index: 90;
  width: 48px;
  height: 48px;
  border: 0;
  border-radius: 50%;
  cursor: pointer;
  font-size: 1.15rem;
  font-weight: 700;
  color: #ffffff;
  background: var(--grad-btn-2);
  box-shadow: var(--shadow-md);
  opacity: 0;
  visibility: hidden;
  transform: translateY(16px) scale(0.9);
  transition: opacity 0.35s var(--ease), transform 0.35s var(--ease), visibility 0.35s var(--ease), filter 0.3s var(--ease);
}

#back-to-top:hover {
  filter: brightness(1.12);
  transform: translateY(-4px) scale(1.05);
}

#back-to-top:focus-visible {
  outline: 3px solid var(--c-accent);
  outline-offset: 3px;
}

body:has(#top:target) #back-to-top,
#back-to-top.is-visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0) scale(1);
}

/* Show back-to-top after user scrolls via scroll-driven animation fallback */
@supports (animation-timeline: scroll()) {
  #back-to-top {
    animation: revealTop linear both;
    animation-timeline: scroll(root);
    animation-range: 300px 600px;
  }
}

@keyframes revealTop {
  from {
    opacity: 0;
    visibility: hidden;
    transform: translateY(16px) scale(0.9);
  }
  to {
    opacity: 1;
    visibility: visible;
    transform: translateY(0) scale(1);
  }
}

/* ============ Focus states ============ */
a:focus-visible,
button:focus-visible,
summary:focus-visible,
input:focus-visible {
  outline: 3px solid var(--c-accent-3);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

/* ============ Responsive ============ */
@media (max-width: 1024px) {
  .header-inner {
    gap: var(--space-sm);
  }

  .site-search input[type="search"] {
    min-width: 120px;
  }

  .nav-list a {
    padding: 6px 10px;
    font-size: 0.86rem;
  }
}

@media (max-width: 860px) {
  :root {
    --space-xl: 40px;
    --space-lg: 24px;
  }

  .header-inner {
    padding: 10px var(--space-md);
    min-height: auto;
  }

  #site-header nav {
    order: 3;
    flex: 1 1 100%;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
  }

  #site-header nav::-webkit-scrollbar {
    display: none;
  }

  .nav-list {
    flex-wrap: nowrap;
    padding-bottom: 4px;
  }

  .nav-list a {
    white-space: nowrap;
  }

  .site-search {
    order: 2;
    margin-left: auto;
  }

  .hero-stats {
    grid-template-columns: repeat(2, 1fr);
  }

  main > section {
    padding: var(--space-md);
  }
}

@media (max-width: 600px) {
  body {
    font-size: 15px;
    line-height: 1.7;
  }

  .header-inner {
    gap: 10px;
  }

  .logo span {
    font-size: 1rem;
  }

  .site-search {
    flex: 1 1 100%;
    order: 3;
  }

  .site-search input[type="search"] {
    flex: 1;
    min-width: 0;
    width: 100%;
  }

  #site-header nav {
    order: 2;
    flex: 1 1 100%;
  }

  .hero-inner {
    padding: 30px 20px;
    border-radius: var(--radius-md);
  }

  .hero-actions {
    flex-direction: column;
    align-items: stretch;
  }

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

  .stat-item {
    padding: 14px 8px;
  }

  .stat-label {
    font-size: 0.74rem;
  }

  .breadcrumb {
    font-size: 0.78rem;
    padding: 8px 14px;
  }

  .sitemap-list,
  .friend-links {
    grid-template-columns: repeat(2, 1fr);
    gap: 8px;
  }

  .sitemap-list a,
  .friend-links a {
    padding: 10px 12px;
    font-size: 0.84rem;
  }

  #contact ul {
    grid-template-columns: 1fr;
  }

  #faq summary {
    padding: 14px 42px 14px 16px;
    font-size: 0.94rem;
  }

  #news article,
  #articles article {
    padding: 14px;
  }

  #back-to-top {
    right: 14px;
    bottom: 16px;
    width: 44px;
    height: 44px;
  }

  #site-footer {
    padding: var(--space-lg) var(--space-md);
  }
}

@media (max-width: 380px) {
  .hero-stats {
    grid-template-columns: 1fr;
  }

  .sitemap-list,
  .friend-links {
    grid-template-columns: 1fr;
  }
}

/* ============ Print ============ */
@media print {
  #site-header,
  #back-to-top,
  #site-footer,
  .hero-actions,
  .site-search {
    display: none !important;
  }

  body {
    background: #fff;
    color: #000;
  }

  main > section {
    box-shadow: none;
    border: 1px solid #ccc;
    break-inside: avoid;
  }
}