:root {
  --color-primary: #4F46E5;
  --color-primary-light: #6366F1;
  --color-primary-lighter: #818CF8;
  --color-primary-soft: #EEF2FF;
  --color-accent: #EC4899;
  --color-accent-light: #F472B6;
  --color-cyan: #06B6D4;
  --color-bg: #F8FAFC;
  --color-bg-alt: #FFFFFF;
  --color-surface: rgba(255, 255, 255, 0.72);
  --color-surface-solid: #FFFFFF;
  --color-text: #1E1B4B;
  --color-text-soft: #475569;
  --color-text-muted: #64748B;
  --color-border: rgba(79, 70, 229, 0.12);
  --color-border-strong: rgba(79, 70, 229, 0.24);
  --shadow-sm: 0 1px 2px rgba(30, 27, 75, 0.06);
  --shadow-md: 0 8px 24px rgba(30, 27, 75, 0.08);
  --shadow-lg: 0 16px 48px rgba(30, 27, 75, 0.12);
  --shadow-glow: 0 12px 40px rgba(79, 70, 229, 0.28);
  --radius-sm: 10px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-xl: 32px;
  --glass-blur: 18px;
  --gradient-hero: linear-gradient(135deg, #4F46E5 0%, #6366F1 38%, #818CF8 68%, #A5B4FC 100%);
  --gradient-accent: linear-gradient(135deg, #4F46E5 0%, #EC4899 100%);
  --gradient-soft: linear-gradient(135deg, #EEF2FF 0%, #F5F3FF 50%, #FDF2F8 100%);
  --gradient-card: linear-gradient(160deg, rgba(255,255,255,0.9) 0%, rgba(238,242,255,0.72) 100%);
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --max-width: 1200px;
  --header-height: 72px;
  --transition-base: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 0.6s cubic-bezier(0.22, 1, 0.36, 1);
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-bg: #0B0A1A;
    --color-bg-alt: #12102A;
    --color-surface: rgba(30, 27, 75, 0.55);
    --color-surface-solid: #17143A;
    --color-text: #EDEBFF;
    --color-text-soft: #C7C4E8;
    --color-text-muted: #9A96C4;
    --color-border: rgba(129, 140, 248, 0.18);
    --color-border-strong: rgba(129, 140, 248, 0.34);
    --color-primary-soft: rgba(79, 70, 229, 0.18);
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.4);
    --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.45);
    --shadow-lg: 0 16px 48px rgba(0, 0, 0, 0.55);
    --shadow-glow: 0 12px 40px rgba(99, 102, 241, 0.35);
    --gradient-hero: linear-gradient(135deg, #1E1B4B 0%, #312E81 38%, #4338CA 68%, #6366F1 100%);
    --gradient-soft: linear-gradient(135deg, #12102A 0%, #1A1740 50%, #221C4A 100%);
    --gradient-card: linear-gradient(160deg, rgba(30, 27, 75, 0.8) 0%, rgba(23, 20, 58, 0.6) 100%);
  }
}

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.75;
  color: var(--color-text);
  background-color: var(--color-bg);
  background-image: radial-gradient(circle at 12% 8%, rgba(99, 102, 241, 0.10) 0%, transparent 42%),
    radial-gradient(circle at 88% 4%, rgba(236, 72, 153, 0.08) 0%, transparent 40%),
    radial-gradient(circle at 50% 100%, rgba(6, 182, 212, 0.06) 0%, transparent 45%);
  background-attachment: fixed;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

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

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

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

a:focus-visible,
button:focus-visible,
input:focus-visible,
summary:focus-visible {
  outline: 3px solid var(--color-primary-lighter);
  outline-offset: 2px;
  border-radius: 6px;
}

h1, h2, h3, h4, h5, h6 {
  margin: 0 0 0.6em;
  line-height: 1.3;
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--color-text);
}

h1 {
  font-size: clamp(1.75rem, 4.2vw, 2.75rem);
  letter-spacing: -0.02em;
}

h2 {
  font-size: clamp(1.4rem, 3vw, 2rem);
  position: relative;
  padding-bottom: 0.5em;
}

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

h3 {
  font-size: clamp(1.1rem, 2.2vw, 1.35rem);
  color: var(--color-primary);
}

p {
  margin: 0 0 1.1em;
  color: var(--color-text-soft);
}

ul, ol {
  margin: 0 0 1.2em;
  padding-left: 1.4em;
  color: var(--color-text-soft);
}

li {
  margin-bottom: 0.5em;
}

li::marker {
  color: var(--color-primary-light);
  font-weight: 700;
}

blockquote {
  margin: 1.5em 0;
  padding: 1.2em 1.5em;
  border-left: 4px solid var(--color-primary-light);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  background: var(--color-surface);
  backdrop-filter: blur(var(--glass-blur));
  -webkit-backdrop-filter: blur(var(--glass-blur));
  box-shadow: var(--shadow-sm);
}

blockquote p {
  margin: 0 0 0.6em;
  font-style: italic;
  color: var(--color-text-soft);
}

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

time {
  display: inline-block;
  font-size: 0.85rem;
  color: var(--color-text-muted);
  font-variant-numeric: tabular-nums;
}

address {
  font-style: normal;
}

/* ============ HEADER ============ */
header[role="banner"] {
  position: sticky;
  top: 0;
  z-index: 100;
  display: grid;
  grid-template-columns: auto 1fr auto;
  grid-template-areas:
    "brand nav search";
  align-items: center;
  gap: 1.5rem;
  padding: 0.75rem clamp(1rem, 4vw, 2.5rem);
  background: var(--color-surface);
  backdrop-filter: blur(var(--glass-blur)) saturate(180%);
  -webkit-backdrop-filter: blur(var(--glass-blur)) saturate(180%);
  border-bottom: 1px solid var(--color-border);
  box-shadow: var(--shadow-md);
  animation: slideDown 0.6s var(--transition-slow) both;
}

@keyframes slideDown {
  from { transform: translateY(-100%); opacity: 0; }
  to { transform: translateY(0); opacity: 1; }
}

.brand {
  grid-area: brand;
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
}

.brand a {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
  color: var(--color-text);
  font-weight: 800;
}

.brand a svg {
  flex-shrink: 0;
  border-radius: 10px;
  box-shadow: var(--shadow-glow);
  transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.brand a:hover svg {
  transform: rotate(-6deg) scale(1.06);
  box-shadow: 0 16px 44px rgba(236, 72, 153, 0.4);
}

.brand-name {
  font-size: 1.15rem;
  letter-spacing: -0.01em;
  background: var(--gradient-accent);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  white-space: nowrap;
}

.brand-slogan {
  margin: 0;
  font-size: 0.72rem;
  color: var(--color-text-muted);
  letter-spacing: 0.02em;
  white-space: nowrap;
}

header nav[role="navigation"] {
  grid-area: nav;
  justify-self: center;
  min-width: 0;
}

header nav[role="navigation"] ul {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.25rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

header nav[role="navigation"] li {
  margin: 0;
}

header nav[role="navigation"] a {
  display: inline-block;
  padding: 0.4rem 0.7rem;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--color-text-soft);
  border-radius: 999px;
  transition: color var(--transition-base), background var(--transition-base), transform var(--transition-base);
}

header nav[role="navigation"] a:hover {
  color: var(--color-primary);
  background: var(--color-primary-soft);
  transform: translateY(-2px);
}

header form[role="search"] {
  grid-area: search;
  display: flex;
  align-items: center;
  gap: 0.4rem;
  position: relative;
}

header form[role="search"] label {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

header form[role="search"] input[type="search"] {
  width: clamp(140px, 18vw, 220px);
  padding: 0.55rem 0.9rem;
  font-size: 0.85rem;
  font-family: inherit;
  color: var(--color-text);
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border-strong);
  border-radius: 999px;
  transition: border-color var(--transition-base), box-shadow var(--transition-base), width var(--transition-base);
}

header form[role="search"] input[type="search"]::placeholder {
  color: var(--color-text-muted);
}

header form[role="search"] input[type="search"]:focus {
  outline: none;
  border-color: var(--color-primary-light);
  box-shadow: 0 0 0 4px rgba(99, 102, 241, 0.18);
  width: clamp(170px, 22vw, 260px);
}

header form[role="search"] button {
  padding: 0.55rem 1rem;
  font-size: 0.85rem;
  font-weight: 700;
  font-family: inherit;
  color: #fff;
  cursor: pointer;
  background: var(--gradient-accent);
  border: none;
  border-radius: 999px;
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition-base), box-shadow var(--transition-base), filter var(--transition-base);
}

header form[role="search"] button:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-glow);
  filter: brightness(1.06);
}

header form[role="search"] button:active {
  transform: translateY(0);
}

/* ============ BREADCRUMB ============ */
body > nav[aria-label="面包屑导航"] {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0.9rem clamp(1rem, 4vw, 2.5rem) 0;
}

body > nav[aria-label="面包屑导航"] ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.4rem;
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: 0.82rem;
}

body > nav[aria-label="面包屑导航"] li {
  margin: 0;
  color: var(--color-text-muted);
}

body > nav[aria-label="面包屑导航"] li + li::before {
  content: "›";
  margin-right: 0.4rem;
  color: var(--color-primary-lighter);
  font-weight: 700;
}

body > nav[aria-label="面包屑导航"] a {
  color: var(--color-text-muted);
  font-weight: 600;
}

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

body > nav[aria-label="面包屑导航"] [aria-current="page"] {
  color: var(--color-primary);
  font-weight: 700;
}

/* ============ MAIN LAYOUT ============ */
main[role="main"] {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 1rem clamp(1rem, 4vw, 2.5rem) 4rem;
}

main > section {
  margin-bottom: clamp(2.5rem, 6vw, 4.5rem);
  padding: clamp(1.4rem, 3.5vw, 2.6rem);
  background: var(--gradient-card);
  backdrop-filter: blur(var(--glass-blur));
  -webkit-backdrop-filter: blur(var(--glass-blur));
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  animation: fadeUp 0.7s var(--transition-slow) both;
  transition: box-shadow var(--transition-base), border-color var(--transition-base), transform var(--transition-base);
}

main > section:hover {
  border-color: var(--color-border-strong);
  box-shadow: var(--shadow-lg);
}

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

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; }
main > section:nth-of-type(5) { animation-delay: 0.25s; }
main > section:nth-of-type(6) { animation-delay: 0.3s; }

/* ============ HERO / INTRO ============ */
#intro {
  position: relative;
  overflow: hidden;
  padding: clamp(2rem, 5vw, 3.5rem);
  background: var(--gradient-hero);
  border: none;
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-glow);
  color: #fff;
}

#intro::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: radial-gradient(circle at 20% 20%, rgba(255, 255, 255, 0.18) 0%, transparent 32%),
    radial-gradient(circle at 82% 76%, rgba(236, 72, 153, 0.35) 0%, transparent 42%),
    radial-gradient(circle at 60% 10%, rgba(6, 182, 212, 0.22) 0%, transparent 35%);
  pointer-events: none;
}

#intro::after {
  content: "";
  position: absolute;
  top: -40%;
  right: -15%;
  width: 420px;
  height: 420px;
  background: radial-gradient(circle, rgba(255, 255, 255, 0.16) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
  animation: floatOrb 12s ease-in-out infinite;
}

@keyframes floatOrb {
  0%, 100% { transform: translate(0, 0) scale(1); }
  50% { transform: translate(-30px, 30px) scale(1.1); }
}

#intro > * {
  position: relative;
  z-index: 1;
}

#intro h1 {
  color: #fff;
  text-shadow: 0 2px 20px rgba(0, 0, 0, 0.22);
  margin-bottom: 0.7em;
}

#intro p {
  color: rgba(255, 255, 255, 0.92);
  font-size: 1.02rem;
  max-width: 72ch;
}

#intro figure {
  margin: 2rem 0 0;
  padding: clamp(0.8rem, 2vw, 1.4rem);
  background: rgba(255, 255, 255, 0.12);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border: 1px solid rgba(255, 255, 255, 0.24);
  border-radius: var(--radius-lg);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.18);
  transition: transform var(--transition-slow), box-shadow var(--transition-slow);
}

#intro figure:hover {
  transform: translateY(-6px) scale(1.005);
  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.28);
}

#intro figure svg {
  border-radius: var(--radius-md);
  width: 100%;
}

#intro figcaption {
  margin-top: 0.8rem;
  font-size: 0.85rem;
  text-align: center;
  color: rgba(255, 255, 255, 0.85);
  letter-spacing: 0.02em;
}

/* ============ ARTICLE CARDS (news / articles) ============ */
#news article,
#articles article {
  position: relative;
  margin-bottom: 1.2rem;
  padding: 1.3rem 1.5rem;
  background: var(--color-surface);
  backdrop-filter: blur(var(--glass-blur));
  -webkit-backdrop-filter: blur(var(--glass-blur));
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition-base), box-shadow var(--transition-base), border-color var(--transition-base);
  overflow: hidden;
}

#news article::before,
#articles article::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 4px;
  background: var(--gradient-accent);
  opacity: 0;
  transition: opacity var(--transition-base);
}

#news article:hover,
#articles article:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--color-border-strong);
}

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

#news article h3,
#articles article h3 {
  margin-bottom: 0.4em;
  transition: color var(--transition-base);
}

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

#articles article a[href] {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  margin-top: 0.4rem;
  padding: 0.4rem 0.95rem;
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--color-primary);
  background: var(--color-primary-soft);
  border-radius: 999px;
  transition: background var(--transition-base), color var(--transition-base), transform var(--transition-base), box-shadow var(--transition-base);
}

#articles article a[href]::after {
  content: "→";
  transition: transform var(--transition-base);
}

#articles article a[href]:hover {
  color: #fff;
  background: var(--gradient-accent);
  transform: translateX(3px);
  box-shadow: var(--shadow-glow);
}

#articles article a[href]:hover::after {
  transform: translateX(3px);
}

/* ============ CASES ============ */
#cases blockquote {
  border-left-color: var(--color-accent-light);
  background: linear-gradient(135deg, rgba(236, 72, 153, 0.06), rgba(79, 70, 229, 0.06));
}

#cases h3 {
  margin-top: 1.6rem;
}

/* ============ FAQ ============ */
#faq details {
  margin-bottom: 0.85rem;
  background: var(--color-surface);
  backdrop-filter: blur(var(--glass-blur));
  -webkit-backdrop-filter: blur(var(--glass-blur));
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  overflow: hidden;
  transition: box-shadow var(--transition-base), border-color var(--transition-base), transform var(--transition-base);
}

#faq details:hover {
  border-color: var(--color-border-strong);
  box-shadow: var(--shadow-md);
}

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

#faq summary {
  position: relative;
  padding: 1rem 3rem 1rem 1.3rem;
  font-weight: 700;
  font-size: 0.98rem;
  color: var(--color-text);
  cursor: pointer;
  list-style: none;
  transition: color var(--transition-base), background var(--transition-base);
  user-select: none;
}

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

#faq summary::after {
  content: "+";
  position: absolute;
  right: 1.1rem;
  top: 50%;
  transform: translateY(-50%);
  display: grid;
  place-items: center;
  width: 26px;
  height: 26px;
  font-size: 1.2rem;
  font-weight: 400;
  line-height: 1;
  color: var(--color-primary);
  background: var(--color-primary-soft);
  border-radius: 50%;
  transition: transform var(--transition-base), background var(--transition-base), color var(--transition-base);
}

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

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

#faq details > p {
  margin: 0;
  padding: 0 1.3rem 1.2rem;
  font-size: 0.94rem;
  color: var(--color-text-soft);
  animation: fadeIn 0.4s var(--transition-base) both;
}

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

/* ============ HOWTO ============ */
#howto ol {
  counter-reset: step;
  list-style: none;
  padding-left: 0;
}

#howto ol > li {
  position: relative;
  counter-increment: step;
  padding: 0.75rem 1rem 0.75rem 3.2rem;
  margin-bottom: 0.6rem;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  transition: transform var(--transition-base), border-color var(--transition-base), box-shadow var(--transition-base);
}

#howto ol > li::before {
  content: counter(step);
  position: absolute;
  left: 0.8rem;
  top: 50%;
  transform: translateY(-50%);
  display: grid;
  place-items: center;
  width: 28px;
  height: 28px;
  font-size: 0.85rem;
  font-weight: 800;
  color: #fff;
  background: var(--gradient-accent);
  border-radius: 50%;
  box-shadow: var(--shadow-sm);
}

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

#howto ul > li {
  position: relative;
}

/* ============ KNOWLEDGE ============ */
#knowledge h3 {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
}

#knowledge h3::before {
  content: "";
  display: inline-block;
  width: 10px;
  height: 10px;
  border-radius: 3px;
  background: var(--gradient-accent);
  transform: rotate(45deg);
}

/* ============ CONTACT ============ */
#contact address {
  padding: 1.3rem 1.5rem;
  background: var(--gradient-soft);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
}

#contact address p {
  margin-bottom: 0.5em;
  font-size: 0.95rem;
}

#contact address p:last-child {
  margin-bottom: 0;
}

#contact address a {
  font-weight: 700;
}

/* ============ SITEMAP / LINKS ============ */
#sitemap ul,
#links ul {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  list-style: none;
  padding: 0;
}

#sitemap li,
#links li {
  margin: 0;
}

#sitemap a,
#links a {
  display: inline-block;
  padding: 0.45rem 1rem;
  font-size: 0.86rem;
  font-weight: 600;
  color: var(--color-text-soft);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 999px;
  transition: color var(--transition-base), background var(--transition-base), border-color var(--transition-base), transform var(--transition-base), box-shadow var(--transition-base);
}

#sitemap a:hover,
#links a:hover {
  color: #fff;
  background: var(--gradient-accent);
  border-color: transparent;
  transform: translateY(-2px);
  box-shadow: var(--shadow-glow);
}

/* ============ FOOTER ============ */
footer[role="contentinfo"] {
  position: relative;
  margin-top: 2rem;
  padding: clamp(2rem, 5vw, 3.5rem) clamp(1rem, 4vw, 2.5rem) 2rem;
  background: var(--gradient-hero);
  color: rgba(255, 255, 255, 0.9);
  overflow: hidden;
}

footer[role="contentinfo"]::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: radial-gradient(circle at 15% 20%, rgba(255, 255, 255, 0.12) 0%, transparent 35%),
    radial-gradient(circle at 85% 80%, rgba(236, 72, 153, 0.28) 0%, transparent 40%);
  pointer-events: none;
}

footer[role="contentinfo"] > * {
  position: relative;
  z-index: 1;
  max-width: var(--max-width);
  margin-left: auto;
  margin-right: auto;
}

footer[role="contentinfo"] section {
  margin-bottom: 1.6rem;
  padding-bottom: 1.2rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.14);
}

footer[role="contentinfo"] section:last-of-type {
  border-bottom: none;
}

footer[role="contentinfo"] h2 {
  font-size: 1rem;
  margin-bottom: 0.5em;
  color: #fff;
  padding-bottom: 0;
}

footer[role="contentinfo"] h2::after {
  display: none;
}

footer[role="contentinfo"] p {
  margin: 0;
  font-size: 0.86rem;
  line-height: 1.7;
  color: rgba(255, 255, 255, 0.78);
}

footer[role="contentinfo"] a {
  color: #fff;
  font-weight: 700;
  text-decoration: underline;
  text-decoration-color: rgba(255, 255, 255, 0.4);
  text-underline-offset: 3px;
  transition: text-decoration-color var(--transition-base), color var(--transition-base);
}

footer[role="contentinfo"] a:hover {
  color: #fff;
  text-decoration-color: #fff;
}

footer[role="contentinfo"] > p {
  text-align: center;
  margin-top: 1rem;
}

footer[role="contentinfo"] > p a {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.55rem 1.3rem;
  font-size: 0.85rem;
  background: rgba(255, 255, 255, 0.14);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.24);
  border-radius: 999px;
  text-decoration: none;
  transition: background var(--transition-base), transform var(--transition-base), box-shadow var(--transition-base);
}

footer[role="contentinfo"] > p a::before {
  content: "↑";
}

footer[role="contentinfo"] > p a:hover {
  background: rgba(255, 255, 255, 0.26);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.2);
}

/* ============ SCROLL REVEAL (progressive enhancement) ============ */
@supports (animation-timeline: view()) {
  main > section {
    animation: none;
    animation-timeline: view();
    animation-range: entry 0% entry 30%;
    animation-fill-mode: both;
  }
}

/* ============ RESPONSIVE ============ */
@media (max-width: 1080px) {
  header[role="banner"] {
    grid-template-columns: 1fr auto;
    grid-template-areas:
      "brand search"
      "nav nav";
    gap: 0.75rem 1rem;
    padding-bottom: 0.75rem;
  }

  header nav[role="navigation"] {
    justify-self: stretch;
    overflow-x: auto;
    scrollbar-width: none;
    -ms-overflow-style: none;
    padding-bottom: 0.25rem;
  }

  header nav[role="navigation"]::-webkit-scrollbar {
    display: none;
  }

  header nav[role="navigation"] ul {
    justify-content: flex-start;
    flex-wrap: nowrap;
  }

  .brand-slogan {
    display: none;
  }
}

@media (max-width: 720px) {
  body {
    font-size: 15px;
  }

  header[role="banner"] {
    grid-template-columns: 1fr;
    grid-template-areas:
      "brand"
      "search"
      "nav";
    gap: 0.6rem;
    padding: 0.7rem 1rem;
  }

  .brand-name {
    font-size: 1.05rem;
  }

  header form[role="search"] {
    width: 100%;
  }

  header form[role="search"] input[type="search"],
  header form[role="search"] input[type="search"]:focus {
    flex: 1;
    width: 100%;
  }

  main[role="main"] {
    padding: 0.75rem 1rem 3rem;
  }

  main > section {
    padding: 1.2rem 1rem;
    border-radius: var(--radius-md);
    margin-bottom: 2rem;
  }

  #intro {
    padding: 1.6rem 1.1rem;
    border-radius: var(--radius-lg);
  }

  #intro p {
    font-size: 0.94rem;
  }

  #intro figure {
    padding: 0.6rem;
  }

  #news article,
  #articles article {
    padding: 1rem 1.1rem;
  }

  #faq summary {
    padding: 0.85rem 2.8rem 0.85rem 1rem;
    font-size: 0.92rem;
  }

  #faq details > p {
    padding: 0 1rem 1rem;
    font-size: 0.88rem;
  }

  #howto ol > li {
    padding: 0.65rem 0.8rem 0.65rem 2.9rem;
    font-size: 0.9rem;
  }

  #sitemap a,
  #links a {
    padding: 0.4rem 0.85rem;
    font-size: 0.8rem;
  }

  blockquote {
    padding: 1rem 1.1rem;
  }

  footer[role="contentinfo"] {
    padding: 2rem 1rem 1.5rem;
  }
}

@media (max-width: 420px) {
  .brand a svg {
    width: 34px;
    height: 34px;
  }

  .brand-name {
    font-size: 0.98rem;
  }

  h1 {
    font-size: 1.5rem;
  }

  h2 {
    font-size: 1.25rem;
  }
}

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

  html {
    scroll-behavior: auto;
  }
}

/* ============ PRINT ============ */
@media print {
  header[role="banner"],
  footer[role="contentinfo"],
  #sitemap,
  #links,
  body > nav[aria-label="面包屑导航"] {
    display: none;
  }

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

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

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

  #intro h1,
  #intro p,
  #intro figcaption {
    color: #000;
  }
}