:root {
  --primary: #1a56db;
  --primary-dark: #1442a8;
  --primary-light: #4f7df3;
  --accent: #6d28d9;
  --accent-2: #0ea5e9;
  --gold: #ffd166;
  --success: #10b981;
  --warning: #f59e0b;
  --bg: #f6f8fc;
  --bg-alt: #ffffff;
  --bg-soft: #eef2fb;
  --text: #1a2233;
  --text-soft: #4a5568;
  --text-muted: #6b7688;
  --border: #e2e8f4;
  --border-strong: #cfd9ec;
  --card-bg: #ffffff;
  --glass-bg: rgba(255, 255, 255, 0.72);
  --glass-border: rgba(255, 255, 255, 0.55);
  --shadow-sm: 0 2px 8px rgba(26, 86, 219, 0.06);
  --shadow-md: 0 8px 24px rgba(26, 86, 219, 0.1);
  --shadow-lg: 0 16px 48px rgba(26, 86, 219, 0.14);
  --radius-sm: 8px;
  --radius: 14px;
  --radius-lg: 22px;
  --radius-xl: 28px;
  --grad-hero: linear-gradient(135deg, #1a56db 0%, #4f46e5 45%, #6d28d9 100%);
  --grad-accent: linear-gradient(135deg, #0ea5e9 0%, #1a56db 100%);
  --grad-soft: linear-gradient(135deg, #eef2fb 0%, #f6f0ff 100%);
  --font: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --maxw: 1200px;
  --header-h: 64px;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
}

@media (prefers-color-scheme: dark) {
  :root {
    --primary: #4f7df3;
    --primary-dark: #3b63d4;
    --primary-light: #7a9dff;
    --accent: #a78bfa;
    --accent-2: #38bdf8;
    --bg: #0d1117;
    --bg-alt: #161b26;
    --bg-soft: #1b2230;
    --text: #e6ebf5;
    --text-soft: #b3bdcf;
    --text-muted: #8792a6;
    --border: #263042;
    --border-strong: #33405a;
    --card-bg: #161b26;
    --glass-bg: rgba(22, 27, 38, 0.72);
    --glass-border: rgba(255, 255, 255, 0.08);
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.4);
    --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.5);
    --shadow-lg: 0 16px 48px rgba(0, 0, 0, 0.6);
    --grad-hero: linear-gradient(135deg, #1442a8 0%, #3730a3 45%, #4c1d95 100%);
    --grad-soft: linear-gradient(135deg, #161b26 0%, #1b1a2e 100%);
  }
}

*, *::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);
  font-size: 16px;
  line-height: 1.75;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

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

a {
  color: var(--primary);
  text-decoration: none;
  transition: color 0.25s var(--ease);
}

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

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

h1 { font-size: clamp(1.6rem, 4vw, 2.5rem); margin: 0 0 1rem; }
h2 { font-size: clamp(1.35rem, 3vw, 1.9rem); margin: 0 0 1.1rem; }
h3 { font-size: clamp(1.08rem, 2vw, 1.3rem); margin: 1.6rem 0 0.7rem; }

p { margin: 0 0 1rem; color: var(--text-soft); }
strong { color: var(--text); font-weight: 600; }

ul, ol { padding-left: 1.4rem; margin: 0 0 1rem; color: var(--text-soft); }
li { margin-bottom: 0.5rem; }

.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(--glass-bg);
  -webkit-backdrop-filter: saturate(180%) blur(16px);
  backdrop-filter: saturate(180%) blur(16px);
  border-bottom: 1px solid var(--border);
  transition: box-shadow 0.3s var(--ease), background 0.3s var(--ease);
}

#site-header:hover {
  box-shadow: var(--shadow-sm);
}

.top-bar {
  background: var(--grad-hero);
  color: #fff;
  font-size: 0.8rem;
  text-align: center;
  padding: 0.4rem 1rem;
  letter-spacing: 0.02em;
}

.top-bar p {
  margin: 0;
  color: rgba(255, 255, 255, 0.92);
  font-size: 0.8rem;
}

.nav-wrap {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0.65rem 1.25rem;
  display: flex;
  align-items: center;
  gap: 1.25rem;
  flex-wrap: wrap;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-weight: 800;
  font-size: 1.15rem;
  color: var(--text);
  flex-shrink: 0;
}

.brand:hover { color: var(--primary); }

.brand svg {
  flex-shrink: 0;
  filter: drop-shadow(0 4px 10px rgba(26, 86, 219, 0.3));
  transition: transform 0.4s var(--ease);
}

.brand:hover svg { transform: rotate(-6deg) scale(1.06); }

.brand-sub {
  display: block;
  font-size: 0.68rem;
  font-weight: 500;
  color: var(--text-muted);
  letter-spacing: 0.1em;
  line-height: 1.2;
}

nav[aria-label="主导航"] { flex: 1 1 auto; }

.main-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.15rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.main-nav li { margin: 0; }

.main-nav a {
  display: block;
  padding: 0.4rem 0.7rem;
  font-size: 0.9rem;
  color: var(--text-soft);
  border-radius: var(--radius-sm);
  position: relative;
  transition: color 0.25s var(--ease), background 0.25s var(--ease);
}

.main-nav a::after {
  content: "";
  position: absolute;
  left: 0.7rem; right: 0.7rem; bottom: 0.15rem;
  height: 2px;
  background: var(--grad-accent);
  border-radius: 2px;
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.3s var(--ease);
}

.main-nav a:hover {
  color: var(--primary);
  background: var(--bg-soft);
}

.main-nav a:hover::after { transform: scaleX(1); }

.site-search {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  flex-shrink: 0;
}

.site-search input[type="search"] {
  width: 180px;
  padding: 0.45rem 0.8rem;
  font-size: 0.85rem;
  font-family: inherit;
  color: var(--text);
  background: var(--bg-alt);
  border: 1px solid var(--border-strong);
  border-radius: 999px;
  outline: none;
  transition: border-color 0.25s var(--ease), box-shadow 0.25s var(--ease), width 0.3s var(--ease);
}

.site-search input[type="search"]::placeholder { color: var(--text-muted); }

.site-search input[type="search"]:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(26, 86, 219, 0.15);
  width: 220px;
}

.site-search button {
  padding: 0.45rem 1rem;
  font-size: 0.85rem;
  font-family: inherit;
  font-weight: 600;
  color: #fff;
  background: var(--grad-accent);
  border: none;
  border-radius: 999px;
  cursor: pointer;
  transition: transform 0.2s var(--ease), box-shadow 0.25s var(--ease), filter 0.25s var(--ease);
}

.site-search button:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 16px rgba(26, 86, 219, 0.35);
  filter: brightness(1.05);
}

.site-search button:active { transform: translateY(0); }

/* ============ Main layout ============ */
main {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 1.25rem 3rem;
}

main > section {
  margin: 2.5rem 0;
  padding: 1.75rem 1.9rem;
  background: var(--card-bg);
  border: 1px solid var(--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 30%;
}

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

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

/* ============ Hero ============ */
.hero {
  position: relative;
  display: grid;
  grid-template-columns: 1.3fr 1fr;
  gap: 2.5rem;
  align-items: center;
  margin: 1.5rem 0 2rem;
  padding: 3rem 2.5rem;
  border-radius: var(--radius-xl);
  background: var(--grad-hero);
  color: #fff;
  overflow: hidden;
  box-shadow: var(--shadow-lg);
  isolation: isolate;
}

.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 12% 18%, rgba(255, 209, 102, 0.28), transparent 42%),
    radial-gradient(circle at 88% 82%, rgba(14, 165, 233, 0.35), transparent 45%);
  z-index: -1;
}

.hero::after {
  content: "";
  position: absolute;
  top: -50%; right: -20%;
  width: 70%; height: 160%;
  background: radial-gradient(circle, rgba(255, 255, 255, 0.12), transparent 60%);
  transform: rotate(18deg);
  z-index: -1;
  pointer-events: none;
}

.hero-text { position: relative; z-index: 1; }

.hero .eyebrow {
  display: inline-block;
  font-size: 0.78rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: #ffe9a8;
  background: rgba(255, 255, 255, 0.14);
  border: 1px solid rgba(255, 255, 255, 0.25);
  padding: 0.28rem 0.85rem;
  border-radius: 999px;
  margin-bottom: 1rem;
  -webkit-backdrop-filter: blur(6px);
  backdrop-filter: blur(6px);
}

.hero h1 {
  color: #fff;
  font-size: clamp(1.7rem, 3.6vw, 2.6rem);
  margin-bottom: 1rem;
  text-shadow: 0 2px 18px rgba(0, 0, 0, 0.18);
}

.hero-lead {
  color: rgba(255, 255, 255, 0.9);
  font-size: 1rem;
  line-height: 1.85;
  margin-bottom: 1.5rem;
}

.hero-lead strong {
  color: #ffe9a8;
  font-weight: 700;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.9rem;
  margin-bottom: 2rem;
}

.btn-primary,
.btn-ghost {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 1.6rem;
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: 999px;
  transition: transform 0.25s var(--ease), box-shadow 0.3s var(--ease), background 0.3s var(--ease), color 0.3s var(--ease);
}

.btn-primary {
  color: var(--primary-dark);
  background: #fff;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.18);
}

.btn-primary:hover {
  color: var(--primary-dark);
  transform: translateY(-3px);
  box-shadow: 0 14px 32px rgba(0, 0, 0, 0.26);
}

.btn-ghost {
  color: #fff;
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.45);
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
}

.btn-ghost:hover {
  color: #fff;
  background: rgba(255, 255, 255, 0.22);
  transform: translateY(-3px);
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1rem;
  margin: 0;
  padding: 1.2rem 0 0;
  border-top: 1px solid rgba(255, 255, 255, 0.2);
}

.hero-stats > div {
  text-align: center;
  padding: 0.3rem 0.2rem;
}

.hero-stats dt {
  font-size: 0.76rem;
  color: rgba(255, 255, 255, 0.75);
  margin-bottom: 0.3rem;
  letter-spacing: 0.04em;
}

.hero-stats dd {
  margin: 0;
  font-size: 1.35rem;
  font-weight: 800;
  color: #fff;
  font-variant-numeric: tabular-nums;
}

.hero-stats .num { color: #ffe9a8; }

.hero-visual {
  position: relative;
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.25);
  padding: 0.75rem;
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.25);
  transition: transform 0.5s var(--ease);
}

.hero-visual:hover { transform: translateY(-6px) scale(1.01); }

.hero-visual svg {
  border-radius: var(--radius);
  width: 100%;
  height: auto;
}

/* ============ Breadcrumb ============ */
.breadcrumb {
  margin: 1.5rem 0 0.5rem;
  font-size: 0.85rem;
}

.breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.4rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.breadcrumb li {
  margin: 0;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.breadcrumb li + li::before {
  content: "/";
  color: var(--border-strong);
}

.breadcrumb a { color: var(--text-muted); }
.breadcrumb a:hover { color: var(--primary); }
.breadcrumb [aria-current="page"] { color: var(--text); font-weight: 600; }

/* ============ Anchor nav ============ */
.anchor-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin: 1.25rem 0 0;
  padding: 0.9rem 1rem;
  background: var(--glass-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  box-shadow: var(--shadow-sm);
  position: sticky;
  top: calc(var(--header-h) + 8px);
  z-index: 50;
}

.anchor-nav a {
  padding: 0.32rem 0.8rem;
  font-size: 0.82rem;
  color: var(--text-soft);
  background: var(--bg-soft);
  border-radius: 999px;
  border: 1px solid transparent;
  transition: all 0.25s var(--ease);
}

.anchor-nav a:hover {
  color: #fff;
  background: var(--grad-accent);
  border-color: transparent;
  transform: translateY(-2px);
  box-shadow: 0 6px 14px rgba(26, 86, 219, 0.3);
}

/* ============ Section content polish ============ */
#intro, #brand, #products, #solutions, #scenarios, #cases, #reviews, #news, #articles, #knowledge, #howto, #faq, #contact, #sitemap, #privacy {
  scroll-margin-top: calc(var(--header-h) + 80px);
}

main > section > h2 {
  position: relative;
  padding-bottom: 0.7rem;
  margin-bottom: 1.3rem;
}

main > section > h2::after {
  content: "";
  position: absolute;
  left: 0; bottom: 0;
  width: 56px; height: 4px;
  border-radius: 4px;
  background: var(--grad-accent);
}

.meta-line {
  font-size: 0.83rem;
  color: var(--text-muted);
  background: var(--bg-soft);
  padding: 0.7rem 1rem;
  border-radius: var(--radius-sm);
  border-left: 3px solid var(--primary);
  margin-top: 1.25rem;
}

/* Timeline */
.timeline {
  list-style: none;
  padding-left: 1.5rem;
  position: relative;
  margin: 1rem 0 1.5rem;
}

.timeline::before {
  content: "";
  position: absolute;
  left: 0.35rem; top: 0.5rem; bottom: 0.5rem;
  width: 2px;
  background: linear-gradient(to bottom, var(--primary), var(--accent));
  border-radius: 2px;
}

.timeline li {
  position: relative;
  padding: 0.4rem 0 0.4rem 0.6rem;
  color: var(--text-soft);
}

.timeline li::before {
  content: "";
  position: absolute;
  left: -1.28rem; top: 0.85rem;
  width: 10px; height: 10px;
  border-radius: 50%;
  background: var(--card-bg);
  border: 2px solid var(--primary);
  box-shadow: 0 0 0 3px rgba(26, 86, 219, 0.12);
  transition: background 0.25s var(--ease), transform 0.25s var(--ease);
}

.timeline li:hover::before {
  background: var(--primary);
  transform: scale(1.2);
}

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

/* Products / lists cards */
#products ul,
#knowledge ul,
#howto ul,
#solutions ul {
  list-style: none;
  padding: 0;
}

#products > ul {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 0.9rem;
}

#products > ul > li {
  margin: 0;
  padding: 1rem 1.1rem;
  background: var(--grad-soft);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: 0.92rem;
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease), border-color 0.3s var(--ease);
}

#products > ul > li:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: var(--primary-light);
}

#knowledge > ul > li,
#howto > ul > li {
  position: relative;
  padding-left: 1.6rem;
}

#knowledge > ul > li::before,
#howto > ul > li::before {
  content: "";
  position: absolute;
  left: 0.2rem; top: 0.65rem;
  width: 8px; height: 8px;
  border-radius: 2px;
  background: var(--grad-accent);
  transform: rotate(45deg);
}

/* Reviews */
blockquote {
  position: relative;
  margin: 1rem 0;
  padding: 1.2rem 1.4rem 1.2rem 3rem;
  background: var(--grad-soft);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease);
}

blockquote::before {
  content: "\201C";
  position: absolute;
  left: 1rem; top: 0.4rem;
  font-size: 3rem;
  line-height: 1;
  color: var(--primary-light);
  opacity: 0.6;
  font-family: Georgia, serif;
}

blockquote p {
  margin: 0;
  font-size: 0.95rem;
  color: var(--text-soft);
  font-style: normal;
}

blockquote:hover {
  transform: translateX(4px);
  box-shadow: var(--shadow-md);
}

/* News */
.news-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.news-list li {
  position: relative;
  padding: 0.85rem 1rem 0.85rem 1.6rem;
  margin: 0 0 0.6rem;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 0.92rem;
  color: var(--text-soft);
  transition: border-color 0.25s var(--ease), transform 0.25s var(--ease), background 0.25s var(--ease);
}

.news-list li::before {
  content: "";
  position: absolute;
  left: 0.7rem; top: 1.35rem;
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--accent-2);
}

.news-list li:hover {
  border-color: var(--primary-light);
  transform: translateX(4px);
  background: var(--bg-soft);
}

.news-list time {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--primary);
  margin-right: 0.6rem;
  font-variant-numeric: tabular-nums;
}

/* Articles */
#articles {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 1.25rem;
  align-items: start;
}

#articles > h2 {
  grid-column: 1 / -1;
}

#articles article {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.35rem 1.4rem;
  transition: transform 0.35s var(--ease), box-shadow 0.35s var(--ease), border-color 0.35s var(--ease);
  position: relative;
  overflow: hidden;
}

#articles article::before {
  content: "";
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: var(--grad-accent);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.4s var(--ease);
}

#articles article:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
  border-color: var(--primary-light);
}

#articles article:hover::before { transform: scaleX(1); }

#articles article h3 {
  margin: 0 0 0.5rem;
  font-size: 1.05rem;
  color: var(--text);
}

.article-meta {
  font-size: 0.78rem;
  color: var(--text-muted);
  margin-bottom: 0.7rem;
  letter-spacing: 0.01em;
}

#articles article p {
  font-size: 0.9rem;
  line-height: 1.7;
  color: var(--text-soft);
  margin-bottom: 0.9rem;
}

#articles article a {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--primary);
}

#articles article a::after {
  content: "→";
  transition: transform 0.25s var(--ease);
}

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

/* HowTo ordered list */
#howto ol {
  counter-reset: step;
  list-style: none;
  padding: 0;
  display: grid;
  gap: 0.75rem;
}

#howto ol li {
  counter-increment: step;
  position: relative;
  padding: 0.9rem 1rem 0.9rem 3.2rem;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  margin: 0;
  font-size: 0.93rem;
  transition: border-color 0.25s var(--ease), transform 0.25s var(--ease), box-shadow 0.25s var(--ease);
}

#howto ol li::before {
  content: counter(step);
  position: absolute;
  left: 0.9rem; top: 50%;
  transform: translateY(-50%);
  width: 28px; height: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.85rem;
  font-weight: 700;
  color: #fff;
  background: var(--grad-accent);
  border-radius: 50%;
  box-shadow: 0 4px 10px rgba(26, 86, 219, 0.3);
}

#howto ol li:hover {
  border-color: var(--primary-light);
  transform: translateX(4px);
  box-shadow: var(--shadow-sm);
}

/* FAQ details */
#faq details {
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  margin-bottom: 0.75rem;
  overflow: hidden;
  transition: border-color 0.25s var(--ease), box-shadow 0.3s var(--ease);
}

#faq details[open] {
  border-color: var(--primary-light);
  box-shadow: var(--shadow-sm);
}

#faq summary {
  position: relative;
  padding: 1rem 3rem 1rem 1.2rem;
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--text);
  cursor: pointer;
  list-style: none;
  transition: color 0.25s var(--ease), background 0.25s var(--ease);
}

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

#faq summary::after {
  content: "+";
  position: absolute;
  right: 1.2rem; top: 50%;
  transform: translateY(-50%);
  font-size: 1.4rem;
  font-weight: 400;
  color: var(--primary);
  transition: transform 0.3s var(--ease), color 0.25s var(--ease);
}

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

#faq summary:hover {
  color: var(--primary);
  background: var(--bg-soft);
}

#faq details p {
  margin: 0;
  padding: 0 1.2rem 1.1rem;
  font-size: 0.92rem;
  color: var(--text-soft);
  animation: fadeIn 0.35s var(--ease);
}

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

/* Contact */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
}

.contact-grid > div {
  padding: 1.4rem 1.5rem;
  background: var(--grad-soft);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease);
}

.contact-grid > div:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.contact-grid h3 {
  margin-top: 0;
  color: var(--primary);
}

.contact-grid p {
  font-size: 0.92rem;
  margin-bottom: 0.5rem;
}

/* Sitemap & friend links */
.sitemap-list,
.friend-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  list-style: none;
  padding: 0;
  margin: 0 0 1.2rem;
}

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

.sitemap-list a,
.friend-links a {
  display: inline-block;
  padding: 0.35rem 0.9rem;
  font-size: 0.85rem;
  color: var(--text-soft);
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: 999px;
  transition: all 0.25s var(--ease);
}

.sitemap-list a:hover,
.friend-links a:hover {
  color: #fff;
  background: var(--grad-accent);
  border-color: transparent;
  transform: translateY(-2px);
  box-shadow: 0 6px 14px rgba(26, 86, 219, 0.28);
}

/* ============ Footer ============ */
#site-footer {
  position: relative;
  background: var(--grad-hero);
  color: rgba(255, 255, 255, 0.85);
  padding: 2.5rem 1.25rem 1.5rem;
  margin-top: 3rem;
  overflow: hidden;
}

#site-footer::before {
  content: "";
  position: absolute;
  top: -60%; left: -10%;
  width: 50%; height: 200%;
  background: radial-gradient(circle, rgba(255, 255, 255, 0.08), transparent 60%);
  pointer-events: none;
}

.footer-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
  position: relative;
  z-index: 1;
}

.footer-inner p {
  color: rgba(255, 255, 255, 0.78);
  font-size: 0.87rem;
  margin-bottom: 0.5rem;
}

.footer-brand {
  font-size: 1.1rem !important;
  font-weight: 800;
  color: #fff !important;
  margin-bottom: 0.8rem !important;
  letter-spacing: 0.02em;
}

.back-top {
  display: inline-block;
  margin: 1.5rem auto 0;
  padding: 0.5rem 1.3rem;
  font-size: 0.85rem;
  font-weight: 600;
  color: #fff;
  background: rgba(255, 255, 255, 0.12);
  border: 1px solid rgba(255, 255, 255, 0.35);
  border-radius: 999px;
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
  position: relative;
  left: 50%;
  transform: translateX(-50%);
  transition: background 0.25s var(--ease), transform 0.25s var(--ease);
}

.back-top:hover {
  color: #fff;
  background: rgba(255, 255, 255, 0.24);
  transform: translateX(-50%) translateY(-3px);
}

/* ============ Responsive ============ */
@media (max-width: 1024px) {
  .hero {
    grid-template-columns: 1fr;
    padding: 2.5rem 2rem;
  }
  .hero-visual { max-width: 520px; margin: 0 auto; }
  .hero-stats { grid-template-columns: repeat(4, 1fr); }
  .contact-grid { grid-template-columns: 1fr; }
  .footer-inner { grid-template-columns: 1fr; gap: 1.25rem; }
}

@media (max-width: 860px) {
  .nav-wrap { gap: 0.75rem; }
  .main-nav { gap: 0.1rem; }
  .main-nav a { padding: 0.35rem 0.55rem; font-size: 0.85rem; }
  .site-search input[type="search"] { width: 140px; }
  .site-search input[type="search"]:focus { width: 170px; }
  .anchor-nav { position: static; }
}

@media (max-width: 680px) {
  body { font-size: 15px; }
  .nav-wrap { padding: 0.6rem 1rem; }
  nav[aria-label="主导航"] { flex-basis: 100%; order: 3; }
  .main-nav {
    justify-content: flex-start;
    overflow-x: auto;
    flex-wrap: nowrap;
    padding-bottom: 0.25rem;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
  }
  .main-nav::-webkit-scrollbar { display: none; }
  .main-nav a { white-space: nowrap; }
  .site-search { margin-left: auto; }
  .site-search input[type="search"] { width: 120px; }
  .site-search input[type="search"]:focus { width: 150px; }

  main { padding: 0 0.9rem 2rem; }
  main > section { padding: 1.35rem 1.15rem; margin: 1.75rem 0; }

  .hero {
    padding: 2rem 1.25rem;
    border-radius: var(--radius-lg);
  }
  .hero-stats { grid-template-columns: repeat(2, 1fr); gap: 0.8rem; }
  .hero-stats dd { font-size: 1.2rem; }
  .hero-actions { gap: 0.6rem; }
  .btn-primary, .btn-ghost { padding: 0.65rem 1.25rem; font-size: 0.9rem; }

  #articles { grid-template-columns: 1fr; }

  .top-bar p { font-size: 0.72rem; }

  blockquote { padding: 1rem 1rem 1rem 2.5rem; }
  blockquote::before { font-size: 2.4rem; left: 0.7rem; }

  #faq summary { padding: 0.9rem 2.6rem 0.9rem 1rem; font-size: 0.92rem; }
  #faq details p { padding: 0 1rem 1rem; }

  .contact-grid > div { padding: 1.15rem 1.2rem; }
}

@media (max-width: 420px) {
  .brand { font-size: 1rem; }
  .brand svg { width: 30px; height: 30px; }
  .site-search input[type="search"] { width: 100px; }
  .site-search input[type="search"]:focus { width: 120px; }
  .site-search button { padding: 0.4rem 0.75rem; font-size: 0.8rem; }
}

/* ============ Reduced motion ============ */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
  main > section { opacity: 1 !important; transform: none !important; }
}

/* ============ Focus visible ============ */
a:focus-visible,
button:focus-visible,
summary:focus-visible,
input:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
  border-radius: 4px;
}

/* ============ Print ============ */
@media print {
  #site-header, .anchor-nav, #site-footer, .hero-visual, .back-top, .site-search { display: none !important; }
  body { background: #fff; color: #000; }
  main > section { box-shadow: none; border: 1px solid #ccc; break-inside: avoid; }
  .hero { background: #fff; color: #000; box-shadow: none; border: 1px solid #ccc; }
  .hero h1, .hero-lead, .hero-stats dd, .hero-stats dt, .hero .eyebrow { color: #000 !important; }
  a { color: #000; text-decoration: underline; }
}