:root {
  --brand: #c0392b;
  --brand-dark: #96281b;
  --brand-light: #e74c3c;
  --accent: #f1c40f;
  --bg: #f7f5f2;
  --bg-alt: #ffffff;
  --surface: rgba(255, 255, 255, 0.72);
  --surface-solid: #ffffff;
  --text: #1f2328;
  --text-soft: #50575e;
  --text-muted: #6b7280;
  --border: rgba(31, 35, 40, 0.1);
  --shadow-sm: 0 2px 8px rgba(31, 35, 40, 0.06);
  --shadow-md: 0 8px 24px rgba(31, 35, 40, 0.1);
  --shadow-lg: 0 16px 48px rgba(31, 35, 40, 0.14);
  --radius-sm: 10px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-pill: 999px;
  --header-h: 72px;
  --maxw: 1200px;
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
  --grad-hero: linear-gradient(135deg, #c0392b 0%, #8e2b20 40%, #2c3e50 100%);
  --grad-brand: linear-gradient(135deg, #e74c3c, #c0392b);
  --grad-accent: linear-gradient(135deg, #f1c40f, #e67e22);
  --glass-blur: saturate(160%) blur(14px);
}

html[data-theme="dark"] {
  --bg: #12151a;
  --bg-alt: #191d24;
  --surface: rgba(30, 35, 43, 0.66);
  --surface-solid: #1e232b;
  --text: #eef1f5;
  --text-soft: #c3cad3;
  --text-muted: #98a1ad;
  --border: rgba(238, 241, 245, 0.12);
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.35);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.45);
  --shadow-lg: 0 16px 48px rgba(0, 0, 0, 0.55);
  --grad-hero: linear-gradient(135deg, #7b241b 0%, #3d1a15 45%, #16202b 100%);
}

@media (prefers-color-scheme: dark) {
  html:not([data-theme="light"]) {
    --bg: #12151a;
    --bg-alt: #191d24;
    --surface: rgba(30, 35, 43, 0.66);
    --surface-solid: #1e232b;
    --text: #eef1f5;
    --text-soft: #c3cad3;
    --text-muted: #98a1ad;
    --border: rgba(238, 241, 245, 0.12);
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.35);
    --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.45);
    --shadow-lg: 0 16px 48px rgba(0, 0, 0, 0.55);
    --grad-hero: linear-gradient(135deg, #7b241b 0%, #3d1a15 45%, #16202b 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: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  font-size: 16px;
  line-height: 1.75;
  color: var(--text);
  background-color: var(--bg);
  background-image:
    radial-gradient(1200px 600px at 100% -10%, rgba(192, 57, 43, 0.08), transparent 60%),
    radial-gradient(900px 500px at -10% 20%, rgba(241, 196, 15, 0.07), transparent 60%);
  background-attachment: fixed;
  transition: background-color 0.35s var(--ease), color 0.35s var(--ease);
  overflow-x: hidden;
}

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

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

a:hover,
a:focus-visible {
  color: var(--brand-light);
}

h1, h2, h3, h4 {
  line-height: 1.3;
  margin: 0 0 0.6em;
  font-weight: 700;
  letter-spacing: 0.01em;
  color: var(--text);
  scroll-margin-top: calc(var(--header-h) + 20px);
}

h1 { font-size: clamp(1.6rem, 1.1rem + 2.2vw, 2.6rem); }
h2 { font-size: clamp(1.35rem, 1.05rem + 1.3vw, 2rem); }
h3 { font-size: clamp(1.1rem, 0.95rem + 0.7vw, 1.35rem); }
h4 { font-size: 1.05rem; }

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

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

ul, ol {
  padding-left: 1.35em;
}

li {
  margin-bottom: 0.35em;
}

.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;
}

:focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 3px;
  border-radius: 4px;
}

::selection {
  background: var(--brand);
  color: #fff;
}

/* ============ Header ============ */
#site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--surface);
  -webkit-backdrop-filter: var(--glass-blur);
  backdrop-filter: var(--glass-blur);
  border-bottom: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
  transition: background 0.35s var(--ease), box-shadow 0.35s var(--ease);
}

.header-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 20px;
  min-height: var(--header-h);
  display: flex;
  align-items: center;
  gap: 20px;
  flex-wrap: wrap;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--text);
  font-weight: 700;
  flex-shrink: 0;
}

.brand:hover {
  color: var(--text);
  opacity: 0.9;
}

.brand svg {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  box-shadow: 0 4px 12px rgba(192, 57, 43, 0.35);
  transition: transform 0.4s var(--ease);
}

.brand:hover svg {
  transform: rotate(-6deg) scale(1.05);
}

.brand-name {
  font-size: 1.05rem;
  letter-spacing: 0.02em;
  background: var(--grad-brand);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.brand-sub {
  font-size: 0.78rem;
  font-weight: 500;
  color: var(--text-muted);
  padding-left: 10px;
  border-left: 1px solid var(--border);
}

#main-nav {
  flex: 1 1 auto;
}

#main-nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 2px;
}

#main-nav a {
  display: inline-block;
  padding: 8px 12px;
  border-radius: var(--radius-pill);
  font-size: 0.92rem;
  color: var(--text-soft);
  position: relative;
  transition: color 0.25s var(--ease), background 0.25s var(--ease), transform 0.25s var(--ease);
}

#main-nav a::after {
  content: "";
  position: absolute;
  left: 50%;
  bottom: 2px;
  width: 0;
  height: 2px;
  border-radius: 2px;
  background: var(--grad-brand);
  transform: translateX(-50%);
  transition: width 0.3s var(--ease);
}

#main-nav a:hover,
#main-nav a:focus-visible {
  color: var(--brand);
  background: rgba(192, 57, 43, 0.08);
}

#main-nav a:hover::after {
  width: 40%;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-left: auto;
}

.search-form {
  display: flex;
  align-items: stretch;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius-pill);
  overflow: hidden;
  transition: border-color 0.25s var(--ease), box-shadow 0.25s var(--ease);
}

.search-form:focus-within {
  border-color: var(--brand);
  box-shadow: 0 0 0 4px rgba(192, 57, 43, 0.15);
}

.search-form input {
  border: 0;
  background: transparent;
  padding: 8px 14px;
  font-size: 0.88rem;
  color: var(--text);
  width: 190px;
  min-width: 0;
  outline: none;
  font-family: inherit;
}

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

.search-form button {
  border: 0;
  padding: 0 16px;
  background: var(--grad-brand);
  color: #fff;
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  font-family: inherit;
  transition: filter 0.25s var(--ease);
}

.search-form button:hover {
  filter: brightness(1.1);
}

#theme-toggle,
#menu-toggle {
  border: 1px solid var(--border);
  background: var(--bg-alt);
  color: var(--text-soft);
  border-radius: var(--radius-pill);
  padding: 8px 14px;
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  font-family: inherit;
  transition: all 0.25s var(--ease);
}

#theme-toggle:hover,
#menu-toggle:hover {
  color: var(--brand);
  border-color: var(--brand);
  transform: translateY(-1px);
  box-shadow: var(--shadow-sm);
}

#menu-toggle {
  display: none;
}

/* ============ Main layout ============ */
main {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 24px 20px 60px;
}

main > section {
  margin-bottom: 56px;
  animation: fadeUp 0.7s var(--ease) both;
}

main > section:nth-of-type(1) { animation-delay: 0.05s; }
main > section:nth-of-type(2) { animation-delay: 0.1s; }
main > section:nth-of-type(3) { animation-delay: 0.15s; }
main > section:nth-of-type(4) { animation-delay: 0.2s; }

@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(24px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ============ Breadcrumb ============ */
.breadcrumb {
  margin-bottom: 20px;
  font-size: 0.85rem;
}

.breadcrumb ol {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
}

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

.breadcrumb li + li::before {
  content: "›";
  margin-right: 6px;
  color: var(--text-muted);
  opacity: 0.6;
}

.breadcrumb a {
  color: var(--text-soft);
  padding: 3px 8px;
  border-radius: var(--radius-pill);
  transition: background 0.25s var(--ease), color 0.25s var(--ease);
}

.breadcrumb a:hover {
  background: rgba(192, 57, 43, 0.1);
  color: var(--brand);
}

.breadcrumb [aria-current="page"] {
  color: var(--brand);
  font-weight: 600;
  padding: 3px 8px;
}

/* ============ Hero ============ */
#hero {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--grad-hero);
  box-shadow: var(--shadow-lg);
  position: relative;
  isolation: isolate;
}

#hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(600px 300px at 85% 15%, rgba(241, 196, 15, 0.25), transparent 70%),
    radial-gradient(500px 260px at 10% 90%, rgba(255, 255, 255, 0.12), transparent 70%);
  z-index: -1;
  pointer-events: none;
}

.hero-media {
  line-height: 0;
  overflow: hidden;
}

.hero-media svg {
  width: 100%;
  height: auto;
  display: block;
  transition: transform 0.8s var(--ease);
}

#hero:hover .hero-media svg {
  transform: scale(1.03);
}

.hero-content {
  padding: 32px 28px 36px;
  color: #fff;
}

.hero-content h1 {
  color: #fff;
  text-shadow: 0 2px 16px rgba(0, 0, 0, 0.3);
  margin-bottom: 0.5em;
}

.hero-lead {
  color: rgba(255, 255, 255, 0.88);
  font-size: 1rem;
  max-width: 62ch;
}

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

.hero-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin: 24px 0 28px;
}

.btn-primary,
.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 26px;
  border-radius: var(--radius-pill);
  font-weight: 700;
  font-size: 0.95rem;
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease), background 0.3s var(--ease);
  will-change: transform;
}

.btn-primary {
  background: var(--grad-accent);
  color: #1f2328;
  box-shadow: 0 8px 22px rgba(241, 196, 15, 0.35);
}

.btn-primary:hover {
  color: #1f2328;
  transform: translateY(-3px);
  box-shadow: 0 14px 30px rgba(241, 196, 15, 0.45);
}

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

.btn-secondary:hover {
  color: #fff;
  background: rgba(255, 255, 255, 0.24);
  transform: translateY(-3px);
  box-shadow: 0 12px 26px rgba(0, 0, 0, 0.25);
}

.hero-stats {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
}

.hero-stats li {
  margin: 0;
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.18);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  border-radius: var(--radius-md);
  padding: 14px 16px;
  display: flex;
  flex-direction: column;
  gap: 2px;
  transition: transform 0.3s var(--ease), background 0.3s var(--ease);
}

.hero-stats li:hover {
  transform: translateY(-4px);
  background: rgba(255, 255, 255, 0.18);
}

.stat-num {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--accent);
  line-height: 1.1;
  font-variant-numeric: tabular-nums;
}

.stat-label {
  font-size: 0.8rem;
  color: rgba(255, 255, 255, 0.85);
}

/* ============ Carousel ============ */
#banner-carousel h2 {
  margin-bottom: 1em;
}

.carousel {
  position: relative;
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--surface-solid);
  box-shadow: var(--shadow-md);
  border: 1px solid var(--border);
}

.slide {
  display: none;
  padding: 0;
  animation: slideIn 0.5s var(--ease);
}

.slide.is-active {
  display: block;
}

@keyframes slideIn {
  from {
    opacity: 0;
    transform: translateX(24px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

.slide svg {
  width: 100%;
  height: auto;
}

.slide h3 {
  padding: 20px 24px 0;
  margin-bottom: 0.4em;
}

.slide p {
  padding: 0 24px 24px;
  margin: 0;
  color: var(--text-soft);
}

.carousel-controls {
  position: absolute;
  top: 50%;
  left: 0;
  right: 0;
  transform: translateY(-50%);
  display: flex;
  justify-content: space-between;
  padding: 0 16px;
  pointer-events: none;
}

.carousel-controls button {
  pointer-events: auto;
  border: 1px solid rgba(255, 255, 255, 0.4);
  background: rgba(20, 24, 30, 0.4);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  color: #fff;
  border-radius: var(--radius-pill);
  padding: 10px 18px;
  font-size: 0.82rem;
  font-weight: 600;
  font-family: inherit;
  cursor: pointer;
  transition: background 0.25s var(--ease), transform 0.25s var(--ease);
}

.carousel-controls button:hover {
  background: var(--brand);
  transform: scale(1.06);
}

/* ============ Generic section cards ============ */
#free-domestic,
#about,
#products,
#solutions,
#scenarios,
#hot-series,
#cases,
#news,
#articles,
#howto,
#faq,
#knowledge,
#contact,
#sitemap,
#links,
#legal,
#author {
  background: var(--surface-solid);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 32px 28px;
  box-shadow: var(--shadow-sm);
  transition: box-shadow 0.35s var(--ease), transform 0.35s var(--ease);
}

#free-domestic:hover,
#about:hover,
#products:hover,
#solutions:hover,
#scenarios:hover,
#hot-series:hover,
#cases:hover,
#news:hover,
#articles:hover,
#howto:hover,
#faq:hover,
#knowledge:hover,
#contact:hover,
#legal:hover {
  box-shadow: var(--shadow-md);
}

#free-domestic h2,
#about h2,
#products h2,
#solutions h2,
#scenarios h2,
#hot-series h2,
#cases h2,
#news h2,
#articles h2,
#howto h2,
#faq h2,
#knowledge h2,
#contact h2,
#sitemap h2,
#links h2,
#legal h2,
#author h2 {
  padding-bottom: 0.5em;
  position: relative;
}

#free-domestic h2::after,
#about h2::after,
#products h2::after,
#solutions h2::after,
#scenarios h2::after,
#hot-series h2::after,
#cases h2::after,
#news h2::after,
#articles h2::after,
#howto h2::after,
#faq h2::after,
#knowledge h2::after,
#contact h2::after,
#sitemap h2::after,
#links h2::after,
#legal h2::after,
#author h2::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 56px;
  height: 4px;
  border-radius: 2px;
  background: var(--grad-brand);
}

/* ============ Series grid ============ */
.series-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
  margin-top: 24px;
}

.series-card {
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: transform 0.35s var(--ease), box-shadow 0.35s var(--ease), border-color 0.35s var(--ease);
}

.series-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
  border-color: rgba(192, 57, 43, 0.35);
}

.series-card svg {
  width: 100%;
  height: auto;
  transition: transform 0.6s var(--ease), filter 0.6s var(--ease);
}

.series-card:hover svg {
  transform: scale(1.06);
  filter: brightness(1.08);
}

.series-card h3 {
  padding: 16px 18px 0;
  margin-bottom: 0.4em;
  font-size: 1.05rem;
}

.series-card p {
  padding: 0 18px;
  margin: 0 0 0.6em;
  font-size: 0.9rem;
  color: var(--text-soft);
}

.series-card .meta {
  padding: 0 18px 18px;
  font-size: 0.78rem;
  color: var(--text-muted);
  letter-spacing: 0.02em;
}

/* ============ News list ============ */
.news-list {
  list-style: none;
  padding: 0;
  margin: 20px 0 0;
  display: grid;
  gap: 14px;
}

.news-list li {
  margin: 0;
  padding: 18px 20px;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-left: 4px solid var(--brand);
  border-radius: var(--radius-sm);
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease), border-left-color 0.3s var(--ease);
}

.news-list li:hover {
  transform: translateX(6px);
  box-shadow: var(--shadow-md);
  border-left-color: var(--accent);
}

.news-list time {
  display: inline-block;
  font-size: 0.78rem;
  color: var(--brand);
  font-weight: 600;
  letter-spacing: 0.04em;
  margin-bottom: 4px;
}

.news-list h3 {
  margin: 0 0 0.3em;
  font-size: 1.02rem;
}

.news-list p {
  margin: 0;
  font-size: 0.9rem;
}

/* ============ Articles / posts ============ */
.post {
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 20px 22px;
  margin-bottom: 16px;
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease), border-color 0.3s var(--ease);
}

.post:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: rgba(192, 57, 43, 0.3);
}

.post h3 {
  margin-bottom: 0.35em;
  font-size: 1.08rem;
}

.post .meta {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 0.7em;
}

.post p {
  font-size: 0.92rem;
}

.post a {
  display: inline-block;
  font-weight: 600;
  font-size: 0.9rem;
  padding: 6px 16px;
  border-radius: var(--radius-pill);
  background: rgba(192, 57, 43, 0.1);
  transition: background 0.25s var(--ease), color 0.25s var(--ease), transform 0.25s var(--ease);
}

.post a:hover {
  background: var(--grad-brand);
  color: #fff;
  transform: translateX(4px);
}

/* ============ HowTo ============ */
#howto ol {
  counter-reset: step;
  list-style: none;
  padding: 0;
  margin: 20px 0;
  display: grid;
  gap: 12px;
}

#howto ol li {
  counter-increment: step;
  position: relative;
  padding: 16px 18px 16px 58px;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  margin: 0;
  font-size: 0.94rem;
  color: var(--text-soft);
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease);
}

#howto ol li::before {
  content: counter(step);
  position: absolute;
  left: 16px;
  top: 50%;
  transform: translateY(-50%);
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: var(--grad-brand);
  color: #fff;
  font-weight: 700;
  font-size: 0.85rem;
  display: grid;
  place-items: center;
  box-shadow: 0 4px 10px rgba(192, 57, 43, 0.3);
}

#howto ol li:hover {
  transform: translateX(6px);
  box-shadow: var(--shadow-sm);
}

/* ============ FAQ ============ */
.faq-list {
  display: grid;
  gap: 12px;
  margin-top: 20px;
}

.faq-list details {
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 0;
  overflow: hidden;
  transition: box-shadow 0.3s var(--ease), border-color 0.3s var(--ease);
}

.faq-list details[open] {
  border-color: rgba(192, 57, 43, 0.35);
  box-shadow: var(--shadow-sm);
}

.faq-list summary {
  cursor: pointer;
  padding: 16px 44px 16px 20px;
  font-weight: 600;
  font-size: 0.96rem;
  color: var(--text);
  position: relative;
  list-style: none;
  transition: background 0.25s var(--ease), color 0.25s var(--ease);
}

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

.faq-list summary::after {
  content: "+";
  position: absolute;
  right: 18px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 1.3rem;
  font-weight: 400;
  color: var(--brand);
  transition: transform 0.3s var(--ease);
}

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

.faq-list summary:hover {
  background: rgba(192, 57, 43, 0.06);
  color: var(--brand);
}

.faq-list details p {
  padding: 0 20px 18px;
  margin: 0;
  font-size: 0.92rem;
  color: var(--text-soft);
  animation: fadeUp 0.4s var(--ease);
}

/* ============ Contact & lists ============ */
.contact-list,
.sitemap-list,
.friend-links {
  list-style: none;
  padding: 0;
  margin: 20px 0;
  display: grid;
  gap: 10px;
}

.contact-list li {
  margin: 0;
  padding: 12px 16px;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 0.92rem;
  color: var(--text-soft);
  transition: transform 0.25s var(--ease), border-color 0.25s var(--ease);
}

.contact-list li:hover {
  transform: translateX(4px);
  border-color: rgba(192, 57, 43, 0.3);
}

.sitemap-list {
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
}

.sitemap-list li {
  margin: 0;
}

.sitemap-list a {
  display: block;
  padding: 10px 14px;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  color: var(--text-soft);
  transition: all 0.25s var(--ease);
}

.sitemap-list a:hover {
  background: rgba(192, 57, 43, 0.08);
  color: var(--brand);
  border-color: rgba(192, 57, 43, 0.3);
  transform: translateY(-2px);
}

.friend-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.friend-links li {
  margin: 0;
}

.friend-links a {
  display: inline-block;
  padding: 8px 18px;
  border-radius: var(--radius-pill);
  background: var(--bg-alt);
  border: 1px solid var(--border);
  font-size: 0.88rem;
  color: var(--text-soft);
  transition: all 0.25s var(--ease);
}

.friend-links a:hover {
  background: var(--grad-brand);
  color: #fff;
  border-color: transparent;
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}

/* ============ Blockquote ============ */
blockquote {
  margin: 16px 0;
  padding: 18px 22px;
  background: var(--bg-alt);
  border-left: 4px solid var(--accent);
  border-radius: var(--radius-sm);
  position: relative;
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease);
}

blockquote:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-sm);
}

blockquote p {
  margin: 0;
  font-style: italic;
  color: var(--text-soft);
  font-size: 0.94rem;
}

/* ============ Footer ============ */
#site-footer {
  background: var(--bg-alt);
  border-top: 1px solid var(--border);
  margin-top: 40px;
  position: relative;
  overflow: hidden;
}

#site-footer::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: var(--grad-brand);
}

.footer-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 40px 20px 32px;
  display: grid;
  gap: 24px;
}

.footer-brand p {
  margin: 0 0 0.5em;
  font-size: 0.9rem;
  color: var(--text-muted);
}

.footer-brand strong {
  font-size: 1.05rem;
  color: var(--text);
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 18px;
}

.footer-links a {
  font-size: 0.88rem;
  color: var(--text-soft);
  position: relative;
  transition: color 0.25s var(--ease);
}

.footer-links a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -3px;
  width: 0;
  height: 2px;
  background: var(--brand);
  transition: width 0.3s var(--ease);
}

.footer-links a:hover {
  color: var(--brand);
}

.footer-links a:hover::after {
  width: 100%;
}

.copyright {
  margin: 0;
  padding-top: 20px;
  border-top: 1px solid var(--border);
  font-size: 0.8rem;
  color: var(--text-muted);
  text-align: center;
}

/* ============ Back to top ============ */
#back-to-top {
  position: fixed;
  right: 20px;
  bottom: 24px;
  z-index: 90;
  border: 0;
  border-radius: var(--radius-pill);
  padding: 12px 20px;
  background: var(--grad-brand);
  color: #fff;
  font-size: 0.85rem;
  font-weight: 700;
  font-family: inherit;
  cursor: pointer;
  box-shadow: 0 8px 22px rgba(192, 57, 43, 0.4);
  opacity: 0;
  visibility: hidden;
  transform: translateY(16px);
  transition: opacity 0.35s var(--ease), transform 0.35s var(--ease), visibility 0.35s, box-shadow 0.3s var(--ease);
}

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

#back-to-top:hover {
  box-shadow: 0 12px 30px rgba(192, 57, 43, 0.55);
  transform: translateY(-3px);
}

/* ============ Responsive ============ */
@media (min-width: 640px) {
  .hero-stats {
    grid-template-columns: repeat(4, 1fr);
  }

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

  .footer-inner {
    grid-template-columns: 1fr 1fr;
    align-items: start;
  }

  .copyright {
    grid-column: 1 / -1;
  }
}

@media (min-width: 900px) {
  #hero {
    grid-template-columns: 1.05fr 1fr;
    align-items: stretch;
  }

  .hero-media {
    display: flex;
    align-items: stretch;
    background: rgba(0, 0, 0, 0.15);
  }

  .hero-media svg {
    height: 100%;
    object-fit: cover;
  }

  .hero-content {
    padding: 48px 40px;
    display: flex;
    flex-direction: column;
    justify-content: center;
  }

  .series-grid {
    grid-template-columns: repeat(3, 1fr);
  }

  #free-domestic,
  #about,
  #products,
  #solutions,
  #scenarios,
  #hot-series,
  #cases,
  #news,
  #articles,
  #howto,
  #faq,
  #knowledge,
  #contact,
  #sitemap,
  #links,
  #legal,
  #author {
    padding: 44px 40px;
  }

  .faq-list {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 980px) {
  .brand-sub {
    display: none;
  }

  .search-form input {
    width: 150px;
  }
}

@media (max-width: 860px) {
  :root {
    --header-h: 64px;
  }

  .header-inner {
    padding: 10px 16px;
    gap: 12px;
  }

  #menu-toggle {
    display: inline-block;
    order: 3;
  }

  #main-nav {
    order: 10;
    flex-basis: 100%;
    display: none;
    padding-bottom: 8px;
  }

  #main-nav.is-open {
    display: block;
    animation: fadeUp 0.3s var(--ease);
  }

  #main-nav ul {
    flex-direction: column;
    gap: 2px;
  }

  #main-nav a {
    display: block;
    padding: 10px 14px;
  }

  #main-nav a::after {
    display: none;
  }

  .header-actions {
    gap: 8px;
  }

  .search-form {
    flex: 1 1 auto;
  }

  .search-form input {
    width: 100%;
    min-width: 0;
    padding: 7px 12px;
  }

  #theme-toggle {
    padding: 7px 12px;
  }
}

@media (max-width: 560px) {
  body {
    font-size: 15px;
  }

  main {
    padding: 16px 14px 40px;
  }

  main > section {
    margin-bottom: 36px;
  }

  .hero-content {
    padding: 24px 18px 28px;
  }

  .hero-cta {
    gap: 10px;
  }

  .btn-primary,
  .btn-secondary {
    padding: 10px 20px;
    font-size: 0.88rem;
    flex: 1 1 auto;
  }

  .hero-stats {
    grid-template-columns: repeat(2, 1fr);
    gap: 8px;
  }

  .stat-num {
    font-size: 1.25rem;
  }

  #free-domestic,
  #about,
  #products,
  #solutions,
  #scenarios,
  #hot-series,
  #cases,
  #news,
  #articles,
  #howto,
  #faq,
  #knowledge,
  #contact,
  #sitemap,
  #links,
  #legal,
  #author {
    padding: 24px 18px;
    border-radius: var(--radius-md);
  }

  .series-card h3,
  .series-card p,
  .series-card .meta {
    padding-left: 14px;
    padding-right: 14px;
  }

  .carousel-controls {
    padding: 0 8px;
  }

  .carousel-controls button {
    padding: 8px 12px;
    font-size: 0.75rem;
  }

  .slide h3 {
    padding: 16px 16px 0;
    font-size: 1rem;
  }

  .slide p {
    padding: 0 16px 18px;
    font-size: 0.88rem;
  }

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

  #back-to-top {
    right: 12px;
    bottom: 16px;
    padding: 10px 16px;
    font-size: 0.8rem;
  }
}

/* ============ Motion preferences ============ */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

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

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

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

  a {
    color: #000;
    text-decoration: underline;
  }
}