:root {
  --primary: #e63946;
  --primary-dark: #c1121f;
  --primary-light: #ff6b6b;
  --accent: #f77f00;
  --accent-2: #fcbf49;
  --grad-start: #e63946;
  --grad-mid: #f77f00;
  --grad-end: #fcbf49;
  --bg: #fff8f5;
  --bg-alt: #ffffff;
  --surface: #ffffff;
  --surface-glass: rgba(255, 255, 255, 0.65);
  --surface-glass-border: rgba(255, 255, 255, 0.4);
  --text: #2b2b2b;
  --text-soft: #5a5a5a;
  --text-muted: #8a8a8a;
  --border: rgba(0, 0, 0, 0.08);
  --shadow-sm: 0 2px 8px rgba(230, 57, 70, 0.08);
  --shadow-md: 0 8px 24px rgba(230, 57, 70, 0.12);
  --shadow-lg: 0 16px 48px rgba(230, 57, 70, 0.18);
  --radius-sm: 10px;
  --radius: 18px;
  --radius-lg: 28px;
  --radius-pill: 999px;
  --header-h: 68px;
  --maxw: 1160px;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  --transition: 0.35s var(--ease);
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #12100f;
    --bg-alt: #1a1614;
    --surface: #1f1a18;
    --surface-glass: rgba(31, 26, 24, 0.6);
    --surface-glass-border: rgba(255, 255, 255, 0.08);
    --text: #f2ece8;
    --text-soft: #c9c0bb;
    --text-muted: #948b86;
    --border: rgba(255, 255, 255, 0.1);
    --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);
  }
}

*,
*::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: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  font-size: 16px;
  line-height: 1.75;
  color: var(--text);
  background-color: var(--bg);
  background-image: radial-gradient(
      circle at 12% 8%,
      rgba(230, 57, 70, 0.08),
      transparent 42%
    ),
    radial-gradient(circle at 88% 4%, rgba(252, 191, 73, 0.12), transparent 40%),
    radial-gradient(circle at 50% 100%, rgba(247, 127, 0, 0.06), transparent 50%);
  background-attachment: fixed;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

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

a {
  color: var(--primary);
  text-decoration: none;
  transition: color var(--transition), opacity var(--transition);
}

a:hover,
a:focus-visible {
  color: var(--primary-dark);
}

:focus-visible {
  outline: 3px solid var(--accent-2);
  outline-offset: 3px;
  border-radius: 4px;
}

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

/* ---------- Header / Nav ---------- */
header {
  position: sticky;
  top: 0;
  z-index: 1000;
  backdrop-filter: blur(18px) saturate(160%);
  -webkit-backdrop-filter: blur(18px) saturate(160%);
  background: var(--surface-glass);
  border-bottom: 1px solid var(--surface-glass-border);
  box-shadow: var(--shadow-sm);
}

header nav {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 20px;
  min-height: var(--header-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}

header nav > a[aria-label="西瓜视频首页"] {
  font-size: 1.35rem;
  font-weight: 800;
  letter-spacing: 0.02em;
  background: linear-gradient(135deg, var(--grad-start), var(--grad-mid) 55%, var(--grad-end));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
  padding: 8px 4px;
  white-space: nowrap;
  transition: transform var(--transition);
}

header nav > a[aria-label="西瓜视频首页"]:hover {
  transform: scale(1.04);
}

header nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  align-items: center;
  gap: 4px;
  flex-wrap: wrap;
}

header nav ul li a {
  display: inline-block;
  padding: 8px 13px;
  font-size: 0.92rem;
  font-weight: 500;
  color: var(--text-soft);
  border-radius: var(--radius-pill);
  position: relative;
  transition: color var(--transition), background var(--transition),
    transform var(--transition);
}

header nav ul li a::after {
  content: "";
  position: absolute;
  left: 50%;
  bottom: 4px;
  width: 0;
  height: 2px;
  border-radius: 2px;
  background: linear-gradient(90deg, var(--grad-start), var(--grad-end));
  transform: translateX(-50%);
  transition: width var(--transition);
}

header nav ul li a:hover,
header nav ul li a:focus-visible {
  color: var(--primary);
  background: rgba(230, 57, 70, 0.08);
  transform: translateY(-1px);
}

header nav ul li a:hover::after {
  width: 60%;
}

/* ---------- Main & Sections ---------- */
main {
  display: block;
}

main > section {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 56px 20px;
  scroll-margin-top: calc(var(--header-h) + 12px);
  animation: fadeUp 0.7s var(--ease) both;
}

@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(26px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Section heading style */
main > section > h2 {
  position: relative;
  font-size: clamp(1.4rem, 3.4vw, 1.9rem);
  font-weight: 800;
  line-height: 1.35;
  margin: 0 0 28px;
  padding-left: 18px;
  color: var(--text);
  letter-spacing: 0.01em;
}

main > section > h2::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.18em;
  bottom: 0.18em;
  width: 6px;
  border-radius: var(--radius-pill);
  background: linear-gradient(180deg, var(--grad-start), var(--grad-end));
  box-shadow: 0 0 16px rgba(230, 57, 70, 0.4);
}

main > section > h3 {
  font-size: clamp(1.05rem, 2.4vw, 1.25rem);
  font-weight: 700;
  color: var(--text);
  margin: 32px 0 12px;
  line-height: 1.4;
}

main > section > h3:first-of-type {
  margin-top: 0;
}

main > section > h4 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--primary);
  margin: 22px 0 8px;
  line-height: 1.45;
}

main > section p {
  margin: 0 0 14px;
  color: var(--text-soft);
  max-width: 78ch;
}

/* ---------- Hero Banner ---------- */
#hero {
  position: relative;
  max-width: none;
  margin: 0;
  padding: 96px 20px 88px;
  text-align: center;
  overflow: hidden;
  border-radius: 0 0 var(--radius-lg) var(--radius-lg);
  background: linear-gradient(
    135deg,
    var(--grad-start) 0%,
    var(--grad-mid) 52%,
    var(--grad-end) 100%
  );
  background-size: 200% 200%;
  animation: gradientShift 14s ease infinite, fadeUp 0.8s var(--ease) both;
  color: #fff;
}

@keyframes gradientShift {
  0%,
  100% {
    background-position: 0% 50%;
  }
  50% {
    background-position: 100% 50%;
  }
}

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

#hero::before {
  width: 420px;
  height: 420px;
  top: -160px;
  left: -120px;
  background: rgba(255, 255, 255, 0.5);
  animation: floatBlob 12s ease-in-out infinite;
}

#hero::after {
  width: 360px;
  height: 360px;
  bottom: -150px;
  right: -100px;
  background: rgba(255, 107, 107, 0.7);
  animation: floatBlob 16s ease-in-out infinite reverse;
}

@keyframes floatBlob {
  0%,
  100% {
    transform: translate(0, 0) scale(1);
  }
  50% {
    transform: translate(30px, -24px) scale(1.08);
  }
}

#hero h1 {
  position: relative;
  z-index: 1;
  max-width: 900px;
  margin: 0 auto 22px;
  font-size: clamp(1.7rem, 5vw, 3rem);
  font-weight: 900;
  line-height: 1.28;
  letter-spacing: 0.01em;
  text-shadow: 0 4px 24px rgba(0, 0, 0, 0.18);
  animation: fadeUp 0.9s var(--ease) 0.1s both;
}

#hero p {
  position: relative;
  z-index: 1;
  max-width: 760px;
  margin: 0 auto;
  font-size: clamp(0.95rem, 2.2vw, 1.1rem);
  line-height: 1.85;
  color: rgba(255, 255, 255, 0.94);
  text-shadow: 0 2px 12px rgba(0, 0, 0, 0.14);
  animation: fadeUp 0.9s var(--ease) 0.22s both;
}

/* ---------- Breadcrumb ---------- */
nav[aria-label="面包屑导航"] {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 16px 20px 0;
}

nav[aria-label="面包屑导航"] ol {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 0;
  padding: 8px 16px;
  font-size: 0.85rem;
  color: var(--text-muted);
  background: var(--surface-glass);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--surface-glass-border);
  border-radius: var(--radius-pill);
  width: fit-content;
  box-shadow: var(--shadow-sm);
}

nav[aria-label="面包屑导航"] ol li {
  display: flex;
  align-items: center;
  gap: 8px;
}

nav[aria-label="面包屑导航"] ol li + li::before {
  content: "›";
  color: var(--primary);
  font-weight: 700;
}

nav[aria-label="面包屑导航"] ol li a {
  color: var(--text-soft);
  font-weight: 500;
}

nav[aria-label="面包屑导航"] ol li a:hover {
  color: var(--primary);
}

/* ---------- Cards: generic section content blocks ---------- */
#about,
#products,
#services,
#scenarios,
#solutions,
#cases,
#news,
#articles,
#faq,
#howto,
#knowledge,
#contact,
#sitemap,
#links,
#legal {
  position: relative;
}

/* Glass card for grouped content */
#about > h3,
#products > h3,
#products > h4,
#services > h3,
#scenarios > h3,
#solutions > h3,
#cases > h3,
#news > h3,
#howto > h3,
#howto > h4,
#knowledge > h3,
#contact > h3,
#legal > h3 {
  position: relative;
}

/* Card wrapping for about/contact/legal blocks */
#about,
#contact,
#legal,
#knowledge {
  background: var(--surface-glass);
  backdrop-filter: blur(16px) saturate(150%);
  -webkit-backdrop-filter: blur(16px) saturate(150%);
  border: 1px solid var(--surface-glass-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  margin-top: 28px;
  margin-bottom: 28px;
  padding: 44px 32px;
}

#about {
  margin-top: 36px;
}

/* ---------- Products ---------- */
#products > h3 + p,
#products > p {
  font-size: 1rem;
}

#products > h4 {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 14px 18px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-left: 4px solid var(--primary);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition), box-shadow var(--transition),
    border-color var(--transition);
}

#products > h4:hover {
  transform: translateX(6px);
  box-shadow: var(--shadow-md);
  border-left-color: var(--accent);
}

#products > h4 + p {
  padding: 0 4px 6px;
}

/* ---------- Services ---------- */
#services > h3 {
  padding: 16px 20px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius) var(--radius) 0 0;
  margin-bottom: 0;
  box-shadow: var(--shadow-sm);
  transition: background var(--transition), color var(--transition);
}

#services > h3 + p {
  padding: 16px 20px;
  margin: 0 0 16px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-top: none;
  border-radius: 0 0 var(--radius) var(--radius);
  box-shadow: var(--shadow-sm);
  transition: box-shadow var(--transition), transform var(--transition);
}

#services > h3:hover {
  color: var(--primary);
}

#services > h3:hover + p {
  box-shadow: var(--shadow-md);
}

/* ---------- Scenarios ---------- */
#scenarios > h3 {
  color: var(--accent);
}

#scenarios > h3 + p {
  padding-left: 16px;
  border-left: 3px solid rgba(247, 127, 0, 0.35);
}

/* ---------- Solutions ---------- */
#solutions {
  background: linear-gradient(
    160deg,
    rgba(230, 57, 70, 0.06),
    rgba(252, 191, 73, 0.08)
  );
  border-radius: var(--radius-lg);
  margin-top: 28px;
  margin-bottom: 28px;
  border: 1px solid var(--border);
}

#solutions > h3 {
  padding: 14px 18px;
  background: var(--surface-glass);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid var(--surface-glass-border);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition), box-shadow var(--transition);
}

#solutions > h3:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
}

#solutions > h3 + p {
  padding: 0 6px;
}

/* ---------- Cases ---------- */
#cases > h3 {
  color: var(--primary-dark);
}

blockquote {
  margin: 24px 0;
  padding: 24px 26px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-left: 5px solid transparent;
  border-image: linear-gradient(180deg, var(--grad-start), var(--grad-end)) 1;
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  position: relative;
  transition: transform var(--transition), box-shadow var(--transition);
}

blockquote::before {
  content: "\201C";
  position: absolute;
  top: -8px;
  left: 14px;
  font-size: 3.4rem;
  line-height: 1;
  font-family: Georgia, serif;
  color: rgba(230, 57, 70, 0.18);
  pointer-events: none;
}

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

blockquote p {
  margin: 0 0 10px;
  font-style: italic;
  color: var(--text-soft);
  padding-left: 8px;
}

blockquote p:last-child {
  margin-bottom: 0;
}

/* ---------- News ---------- */
#news > h3 {
  position: relative;
  padding: 18px 22px 18px 52px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  margin-bottom: 0;
  transition: transform var(--transition), box-shadow var(--transition),
    border-color var(--transition);
}

#news > h3::before {
  content: "";
  position: absolute;
  left: 20px;
  top: 50%;
  transform: translateY(-50%);
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--grad-start), var(--grad-end));
  box-shadow: 0 0 0 4px rgba(230, 57, 70, 0.14);
}

#news > h3:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
  border-color: rgba(230, 57, 70, 0.3);
}

#news > h3 + p {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin: 8px 0 6px;
  padding-left: 52px;
}

#news > h3 + p + p {
  padding: 0 22px 18px 52px;
  margin: 0 0 18px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-top: none;
  border-radius: 0 0 var(--radius) var(--radius);
  box-shadow: var(--shadow-sm);
  color: var(--text-soft);
}

/* ---------- Articles ---------- */
#articles > article {
  position: relative;
  padding: 26px 24px;
  margin-bottom: 20px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  overflow: hidden;
  transition: transform var(--transition), box-shadow var(--transition),
    border-color var(--transition);
}

#articles > article::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 4px;
  background: linear-gradient(90deg, var(--grad-start), var(--grad-mid), var(--grad-end));
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.45s var(--ease);
}

#articles > article:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
  border-color: rgba(230, 57, 70, 0.25);
}

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

#articles > article h3 {
  font-size: 1.12rem;
  font-weight: 700;
  margin: 0 0 8px;
  color: var(--text);
  line-height: 1.45;
  transition: color var(--transition);
}

#articles > article:hover h3 {
  color: var(--primary);
}

#articles > article > p:first-of-type {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin: 0 0 10px;
  display: inline-block;
  padding: 2px 12px;
  background: rgba(230, 57, 70, 0.08);
  border-radius: var(--radius-pill);
}

#articles > article > p {
  color: var(--text-soft);
  margin: 0 0 12px;
}

#articles > article > p a {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--primary);
  padding: 6px 16px;
  border-radius: var(--radius-pill);
  background: rgba(230, 57, 70, 0.08);
  transition: background var(--transition), color var(--transition),
    transform var(--transition), box-shadow var(--transition);
}

#articles > article > p a::after {
  content: "→";
  transition: transform var(--transition);
}

#articles > article > p a:hover {
  background: linear-gradient(135deg, var(--grad-start), var(--grad-mid));
  color: #fff;
  transform: translateX(3px);
  box-shadow: 0 6px 18px rgba(230, 57, 70, 0.32);
}

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

/* ---------- FAQ ---------- */
#faq {
  counter-reset: faq;
}

#faq > h3 {
  counter-increment: faq;
  position: relative;
  padding: 18px 22px 18px 64px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius) var(--radius) 0 0;
  margin-bottom: 0;
  font-size: 1.02rem;
  box-shadow: var(--shadow-sm);
  cursor: default;
  transition: background var(--transition), color var(--transition);
}

#faq > h3::before {
  content: "Q" counter(faq);
  position: absolute;
  left: 18px;
  top: 50%;
  transform: translateY(-50%);
  display: flex;
  align-items: center;
  justify-content: center;
  min-width: 32px;
  height: 32px;
  padding: 0 6px;
  font-size: 0.82rem;
  font-weight: 800;
  color: #fff;
  background: linear-gradient(135deg, var(--grad-start), var(--grad-mid));
  border-radius: var(--radius-pill);
  box-shadow: 0 4px 12px rgba(230, 57, 70, 0.3);
}

#faq > h3:hover {
  color: var(--primary);
  background: rgba(230, 57, 70, 0.04);
}

#faq > h3 + p {
  padding: 16px 22px 18px 64px;
  margin: 0 0 16px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-top: none;
  border-radius: 0 0 var(--radius) var(--radius);
  box-shadow: var(--shadow-sm);
  color: var(--text-soft);
  transition: box-shadow var(--transition);
}

#faq > h3:hover + p {
  box-shadow: var(--shadow-md);
}

/* ---------- HowTo ---------- */
#howto {
  background: var(--surface-glass);
  backdrop-filter: blur(16px) saturate(150%);
  -webkit-backdrop-filter: blur(16px) saturate(150%);
  border: 1px solid var(--surface-glass-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  margin-top: 28px;
  margin-bottom: 28px;
  padding: 44px 32px;
}

#howto > h4 {
  position: relative;
  padding: 12px 16px 12px 46px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  margin: 14px 0 8px;
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition), box-shadow var(--transition),
    border-color var(--transition);
}

#howto > h4::before {
  content: "";
  position: absolute;
  left: 18px;
  top: 50%;
  transform: translateY(-50%);
  width: 14px;
  height: 14px;
  border-radius: 4px;
  background: linear-gradient(135deg, var(--grad-start), var(--grad-end));
  box-shadow: 0 0 0 3px rgba(230, 57, 70, 0.12);
}

#howto > h4:hover {
  transform: translateX(5px);
  box-shadow: var(--shadow-md);
  border-color: rgba(230, 57, 70, 0.25);
}

#howto > h4 + p {
  padding: 0 4px 8px 46px;
  margin: 0 0 10px;
}

/* ---------- Contact ---------- */
#contact > p {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 10px 16px;
  margin: 0 0 8px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition), box-shadow var(--transition),
    border-color var(--transition);
  word-break: break-word;
}

#contact > p:hover {
  transform: translateX(5px);
  box-shadow: var(--shadow-md);
  border-color: rgba(230, 57, 70, 0.25);
}

#contact a {
  font-weight: 600;
}

/* ---------- Sitemap & Links ---------- */
#sitemap ul,
#links ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  gap: 12px;
}

#sitemap ul li a,
#links ul li a {
  display: block;
  padding: 12px 18px;
  font-size: 0.92rem;
  font-weight: 500;
  color: var(--text-soft);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-sm);
  text-align: center;
  transition: transform var(--transition), box-shadow var(--transition),
    color var(--transition), border-color var(--transition),
    background var(--transition);
}

#sitemap ul li a::before {
  content: "▸ ";
  color: var(--primary);
  font-weight: 700;
  transition: transform var(--transition);
  display: inline-block;
}

#sitemap ul li a:hover,
#links ul li a:hover,
#sitemap ul li a:focus-visible,
#links ul li a:focus-visible {
  transform: translateY(-4px);
  color: var(--primary);
  border-color: rgba(230, 57, 70, 0.35);
  box-shadow: var(--shadow-md);
  background: rgba(230, 57, 70, 0.05);
}

#sitemap ul li a:hover::before {
  transform: translateX(4px);
}

/* ---------- Legal ---------- */
#legal p {
  font-size: 0.92rem;
}

/* ---------- Footer ---------- */
footer {
  position: relative;
  margin-top: 40px;
  padding: 48px 20px 56px;
  text-align: center;
  color: rgba(255, 255, 255, 0.92);
  background: linear-gradient(
    135deg,
    #2b1a1c 0%,
    #3a1f22 50%,
    #2b1a1c 100%
  );
  overflow: hidden;
}

footer::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 4px;
  background: linear-gradient(90deg, var(--grad-start), var(--grad-mid), var(--grad-end));
}

footer p {
  max-width: var(--maxw);
  margin: 0 auto 10px;
  font-size: 0.88rem;
  line-height: 1.7;
  color: rgba(255, 255, 255, 0.78);
}

footer p:first-child {
  font-weight: 600;
  color: rgba(255, 255, 255, 0.95);
  letter-spacing: 0.02em;
}

/* ---------- Scroll reveal via animation delays (progressive enhancement) ---------- */
main > section:nth-of-type(2n) {
  animation-delay: 0.05s;
}

main > section:nth-of-type(3n) {
  animation-delay: 0.1s;
}

/* ---------- Responsive: Tablet ---------- */
@media (max-width: 900px) {
  :root {
    --header-h: 60px;
    --radius-lg: 22px;
  }

  header nav {
    padding: 8px 16px;
    gap: 8px;
  }

  header nav ul {
    gap: 0;
    justify-content: center;
    width: 100%;
    padding-bottom: 6px;
  }

  header nav ul li a {
    padding: 6px 10px;
    font-size: 0.84rem;
  }

  main > section {
    padding: 40px 16px;
  }

  #hero {
    padding: 72px 16px 64px;
  }

  #about,
  #contact,
  #legal,
  #knowledge,
  #howto {
    padding: 32px 20px;
    border-radius: var(--radius);
  }

  nav[aria-label="面包屑导航"] {
    padding: 12px 16px 0;
  }
}

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

  header nav {
    flex-direction: column;
    align-items: flex-start;
    padding: 10px 14px 6px;
  }

  header nav > a[aria-label="西瓜视频首页"] {
    font-size: 1.2rem;
    align-self: center;
  }

  header nav ul {
    justify-content: flex-start;
    overflow-x: auto;
    flex-wrap: nowrap;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
    padding: 4px 0 8px;
    width: 100%;
  }

  header nav ul::-webkit-scrollbar {
    display: none;
  }

  header nav ul li {
    flex: 0 0 auto;
  }

  header nav ul li a {
    white-space: nowrap;
    padding: 7px 12px;
    font-size: 0.82rem;
  }

  main > section {
    padding: 32px 14px;
  }

  main > section > h2 {
    font-size: 1.3rem;
    padding-left: 14px;
    margin-bottom: 20px;
  }

  main > section > h2::before {
    width: 5px;
  }

  main > section > h3 {
    font-size: 1.02rem;
    margin: 24px 0 10px;
  }

  #hero {
    padding: 56px 14px 52px;
    border-radius: 0 0 var(--radius) var(--radius);
  }

  #hero h1 {
    font-size: 1.5rem;
    margin-bottom: 16px;
  }

  #hero p {
    font-size: 0.92rem;
    line-height: 1.8;
  }

  #hero::before {
    width: 260px;
    height: 260px;
    top: -110px;
    left: -90px;
  }

  #hero::after {
    width: 220px;
    height: 220px;
    bottom: -100px;
    right: -70px;
  }

  nav[aria-label="面包屑导航"] ol {
    font-size: 0.78rem;
    padding: 6px 12px;
    gap: 6px;
  }

  #about,
  #contact,
  #legal,
  #knowledge,
  #howto {
    padding: 24px 16px;
    margin-top: 20px;
    margin-bottom: 20px;
  }

  #products > h4 {
    padding: 12px 14px;
    font-size: 0.95rem;
  }

  #services > h3 {
    padding: 12px 16px;
    font-size: 1rem;
  }

  #services > h3 + p {
    padding: 12px 16px;
  }

  #news > h3 {
    padding: 14px 16px 14px 44px;
    font-size: 1rem;
  }

  #news > h3::before {
    left: 16px;
    width: 10px;
    height: 10px;
  }

  #news > h3 + p {
    padding-left: 44px;
  }

  #news > h3 + p + p {
    padding: 0 16px 14px 44px;
  }

  #articles > article {
    padding: 20px 16px;
  }

  #articles > article h3 {
    font-size: 1.02rem;
  }

  #faq > h3 {
    padding: 14px 16px 14px 54px;
    font-size: 0.96rem;
  }

  #faq > h3::before {
    left: 14px;
    min-width: 28px;
    height: 28px;
    font-size: 0.75rem;
  }

  #faq > h3 + p {
    padding: 14px 16px 16px 54px;
  }

  #howto > h4 {
    padding: 10px 12px 10px 40px;
    font-size: 0.94rem;
  }

  #howto > h4::before {
    left: 14px;
    width: 12px;
    height: 12px;
  }

  #howto > h4 + p {
    padding-left: 40px;
  }

  #contact > p {
    padding: 9px 12px;
    font-size: 0.9rem;
  }

  #sitemap ul,
  #links ul {
    grid-template-columns: repeat(auto-fill, minmax(130px, 1fr));
    gap: 10px;
  }

  #sitemap ul li a,
  #links ul li a {
    padding: 10px 12px;
    font-size: 0.86rem;
  }

  blockquote {
    padding: 20px 18px;
  }

  footer {
    padding: 36px 16px 44px;
  }

  footer p {
    font-size: 0.8rem;
  }
}

/* ---------- Reduced motion ---------- */
@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;
  }
}

/* ---------- Print ---------- */
@media print {
  header,
  footer,
  #hero::before,
  #hero::after {
    display: none;
  }

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

  main > section {
    animation: none;
    box-shadow: none;
    page-break-inside: avoid;
  }

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