:root {
  --color-primary: #2b5f8e;
  --color-primary-dark: #1d4468;
  --color-primary-light: #4a7fae;
  --color-accent: #f2b544;
  --color-accent-dark: #d99a26;
  --color-bg: #f4f7fb;
  --color-bg-alt: #eaeff6;
  --color-surface: #ffffff;
  --color-surface-glass: rgba(255, 255, 255, 0.72);
  --color-text: #1f2d3d;
  --color-text-soft: #4a5a6a;
  --color-text-muted: #7a8a99;
  --color-border: #dbe4ee;
  --color-border-soft: rgba(43, 95, 142, 0.12);
  --color-shadow: rgba(31, 45, 61, 0.08);
  --color-shadow-strong: rgba(31, 45, 61, 0.16);
  --gradient-hero: linear-gradient(135deg, #2b5f8e 0%, #3d7ab0 45%, #f2b544 130%);
  --gradient-accent: linear-gradient(135deg, #f2b544 0%, #f7cd7a 100%);
  --gradient-glass: linear-gradient(135deg, rgba(255, 255, 255, 0.82) 0%, rgba(255, 255, 255, 0.55) 100%);
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 22px;
  --radius-pill: 999px;
  --space-xs: 0.4rem;
  --space-sm: 0.75rem;
  --space-md: 1.25rem;
  --space-lg: 2rem;
  --space-xl: 3.25rem;
  --max-width: 1180px;
  --font-sans: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Source Han Sans SC", "Noto Sans CJK SC", system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --transition-fast: 0.18s ease;
  --transition-base: 0.3s cubic-bezier(0.22, 0.61, 0.36, 1);
  --header-offset: 132px;
}

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  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(43, 95, 142, 0.08), transparent 42%),
    radial-gradient(circle at 88% 0%, rgba(242, 181, 68, 0.1), transparent 38%);
  background-attachment: fixed;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: -1;
  background-image:
    linear-gradient(rgba(43, 95, 142, 0.025) 1px, transparent 1px),
    linear-gradient(90deg, rgba(43, 95, 142, 0.025) 1px, transparent 1px);
  background-size: 44px 44px;
  mask-image: radial-gradient(circle at 50% 20%, #000 0%, transparent 78%);
  -webkit-mask-image: radial-gradient(circle at 50% 20%, #000 0%, transparent 78%);
}

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

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

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

a:focus-visible,
button:focus-visible,
input:focus-visible,
summary:focus-visible {
  outline: 3px solid rgba(242, 181, 68, 0.65);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

h1,
h2,
h3,
h4 {
  line-height: 1.3;
  color: var(--color-text);
  font-weight: 700;
  margin: 0 0 var(--space-sm);
  letter-spacing: 0.01em;
}

h1 {
  font-size: clamp(1.6rem, 3.6vw, 2.5rem);
}

h2 {
  font-size: clamp(1.3rem, 2.6vw, 1.85rem);
  position: relative;
  padding-left: 0.85rem;
}

h2::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.18em;
  bottom: 0.18em;
  width: 5px;
  border-radius: var(--radius-pill);
  background: var(--gradient-accent);
}

h3 {
  font-size: clamp(1.08rem, 1.8vw, 1.28rem);
  margin-top: var(--space-md);
}

p {
  margin: 0 0 var(--space-sm);
  color: var(--color-text-soft);
}

ul,
ol {
  margin: 0 0 var(--space-md);
  padding-left: 1.35rem;
  color: var(--color-text-soft);
}

li {
  margin-bottom: 0.35rem;
}

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

small {
  color: var(--color-text-muted);
  font-size: 0.82rem;
}

blockquote {
  margin: 0 0 var(--space-md);
  padding: var(--space-md) var(--space-md) var(--space-md) 1.4rem;
  border-left: 4px solid var(--color-accent);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  background: var(--color-surface-glass);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  box-shadow: 0 6px 20px var(--color-shadow);
  transition: transform var(--transition-base), box-shadow var(--transition-base);
}

blockquote:hover {
  transform: translateX(4px);
  box-shadow: 0 10px 28px var(--color-shadow-strong);
}

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

/* ============ 头部 ============ */
#site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--color-surface-glass);
  backdrop-filter: blur(16px) saturate(160%);
  -webkit-backdrop-filter: blur(16px) saturate(160%);
  border-bottom: 1px solid var(--color-border-soft);
  box-shadow: 0 4px 22px rgba(31, 45, 61, 0.06);
}

.top-bar {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: var(--space-xs) var(--space-md);
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0.45rem var(--space-md);
  font-size: 0.78rem;
  color: var(--color-text-muted);
  border-bottom: 1px dashed var(--color-border-soft);
}

.top-bar p {
  margin: 0;
  color: inherit;
}

.nav-wrap {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  max-width: var(--max-width);
  margin: 0 auto;
  padding: var(--space-sm) var(--space-md);
  flex-wrap: wrap;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  font-weight: 700;
  font-size: 1.02rem;
  color: var(--color-primary-dark);
  letter-spacing: 0.01em;
  white-space: nowrap;
}

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

.brand svg {
  flex: none;
  filter: drop-shadow(0 4px 10px rgba(43, 95, 142, 0.28));
  transition: transform var(--transition-base);
}

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

.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: inline-block;
  padding: 0.4rem 0.7rem;
  font-size: 0.9rem;
  color: var(--color-text-soft);
  border-radius: var(--radius-pill);
  position: relative;
  transition: color var(--transition-fast), background var(--transition-fast);
}

.main-nav a::after {
  content: "";
  position: absolute;
  left: 50%;
  bottom: 2px;
  width: 0;
  height: 2px;
  border-radius: var(--radius-pill);
  background: var(--gradient-accent);
  transform: translateX(-50%);
  transition: width var(--transition-base);
}

.main-nav a:hover,
.main-nav a:focus-visible {
  color: var(--color-primary-dark);
  background: rgba(43, 95, 142, 0.07);
}

.main-nav a:hover::after {
  width: 60%;
}

.site-search {
  display: flex;
  align-items: center;
  gap: 0.35rem;
  margin-left: auto;
  padding: 0.25rem;
  border-radius: var(--radius-pill);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  box-shadow: inset 0 1px 2px rgba(31, 45, 61, 0.04);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.site-search:focus-within {
  border-color: var(--color-primary-light);
  box-shadow: 0 0 0 4px rgba(43, 95, 142, 0.12);
}

.site-search label {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
}

.site-search input {
  border: 0;
  background: transparent;
  padding: 0.35rem 0.7rem;
  font-size: 0.88rem;
  font-family: inherit;
  color: var(--color-text);
  min-width: 160px;
  border-radius: var(--radius-pill);
}

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

.site-search input:focus {
  outline: none;
}

.site-search button {
  border: 0;
  cursor: pointer;
  padding: 0.4rem 1rem;
  font-size: 0.85rem;
  font-family: inherit;
  font-weight: 600;
  color: #fff;
  border-radius: var(--radius-pill);
  background: var(--gradient-accent);
  box-shadow: 0 4px 12px rgba(242, 181, 68, 0.35);
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.site-search button:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 18px rgba(242, 181, 68, 0.5);
}

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

#menu-toggle,
#theme-toggle {
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  color: var(--color-text-soft);
  font-family: inherit;
  font-size: 0.85rem;
  font-weight: 600;
  padding: 0.45rem 0.9rem;
  border-radius: var(--radius-pill);
  cursor: pointer;
  transition: all var(--transition-fast);
}

#menu-toggle {
  display: none;
}

#menu-toggle:hover,
#theme-toggle:hover {
  color: var(--color-primary-dark);
  border-color: var(--color-primary-light);
  background: rgba(43, 95, 142, 0.06);
  transform: translateY(-1px);
}

#mobile-menu {
  border-top: 1px solid var(--color-border-soft);
  background: var(--color-surface-glass);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  animation: slideDown 0.28s ease both;
}

#mobile-menu[hidden] {
  display: none;
}

#mobile-menu ul {
  list-style: none;
  margin: 0;
  padding: var(--space-sm) var(--space-md);
  display: grid;
  gap: 0.2rem;
}

#mobile-menu a {
  display: block;
  padding: 0.6rem 0.75rem;
  border-radius: var(--radius-sm);
  color: var(--color-text-soft);
  font-size: 0.92rem;
}

#mobile-menu a:hover {
  background: rgba(43, 95, 142, 0.08);
  color: var(--color-primary-dark);
}

@keyframes slideDown {
  from { opacity: 0; transform: translateY(-8px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ============ 主内容容器 ============ */
main {
  display: block;
}

main > section,
main > nav {
  max-width: var(--max-width);
  margin: 0 auto var(--space-lg);
  padding: var(--space-lg) var(--space-md);
  background: var(--color-surface);
  border: 1px solid var(--color-border-soft);
  border-radius: var(--radius-lg);
  box-shadow: 0 10px 32px var(--color-shadow);
  scroll-margin-top: var(--header-offset);
  animation: fadeUp 0.6s cubic-bezier(0.22, 0.61, 0.36, 1) both;
  animation-timeline: view();
  animation-range: entry 0% entry 35%;
}

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

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

/* ============ Hero ============ */
#hero {
  position: relative;
  max-width: none;
  margin: 0 0 var(--space-lg);
  padding: clamp(2.2rem, 6vw, 4.5rem) var(--space-md) clamp(3rem, 7vw, 5rem);
  border-radius: 0 0 var(--radius-lg) var(--radius-lg);
  border: 0;
  background: var(--gradient-hero);
  background-size: 200% 200%;
  animation: gradientShift 16s ease infinite;
  color: #fff;
  overflow: hidden;
  box-shadow: 0 18px 48px rgba(29, 68, 104, 0.28);
  scroll-margin-top: var(--header-offset);
}

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

#hero::before,
#hero::after {
  content: "";
  position: absolute;
  border-radius: 50%;
  pointer-events: none;
  filter: blur(2px);
}

#hero::before {
  width: 420px;
  height: 420px;
  right: -120px;
  top: -160px;
  background: radial-gradient(circle, rgba(242, 181, 68, 0.42), transparent 68%);
  animation: floatBlob 12s ease-in-out infinite;
}

#hero::after {
  width: 320px;
  height: 320px;
  left: -110px;
  bottom: -150px;
  background: radial-gradient(circle, rgba(255, 255, 255, 0.22), transparent 70%);
  animation: floatBlob 15s ease-in-out infinite reverse;
}

@keyframes floatBlob {
  0%, 100% { transform: translate(0, 0) scale(1); }
  50% { transform: translate(-18px, 22px) scale(1.08); }
}

#hero > * {
  position: relative;
  z-index: 1;
  max-width: var(--max-width);
  margin-left: auto;
  margin-right: auto;
}

#hero h1 {
  color: #fff;
  text-shadow: 0 2px 18px rgba(0, 0, 0, 0.18);
  max-width: 900px;
}

#hero .hero-lead {
  color: rgba(255, 255, 255, 0.92);
  font-size: clamp(0.95rem, 1.6vw, 1.06rem);
  max-width: 860px;
  line-height: 1.85;
}

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

.btn-primary,
.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.72rem 1.6rem;
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: var(--radius-pill);
  transition: transform var(--transition-base), box-shadow var(--transition-base), background var(--transition-base), color var(--transition-base);
  will-change: transform;
}

.btn-primary {
  color: var(--color-primary-dark);
  background: var(--gradient-accent);
  box-shadow: 0 8px 24px rgba(242, 181, 68, 0.42);
}

.btn-primary:hover {
  color: var(--color-primary-dark);
  transform: translateY(-3px);
  box-shadow: 0 14px 34px rgba(242, 181, 68, 0.55);
}

.btn-secondary {
  color: #fff;
  background: rgba(255, 255, 255, 0.14);
  border: 1px solid rgba(255, 255, 255, 0.42);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}

.btn-secondary:hover {
  color: #fff;
  background: rgba(255, 255, 255, 0.24);
  transform: translateY(-3px);
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.18);
}

#hero figure {
  margin: 0;
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.28);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  box-shadow: 0 16px 40px rgba(0, 0, 0, 0.22);
  transition: transform var(--transition-base), box-shadow var(--transition-base);
}

#hero figure:hover {
  transform: translateY(-4px);
  box-shadow: 0 24px 56px rgba(0, 0, 0, 0.3);
}

#hero figure svg {
  width: 100%;
  height: auto;
  border-radius: var(--radius-md) var(--radius-md) 0 0;
}

#hero figcaption {
  padding: 0.7rem var(--space-md);
  font-size: 0.85rem;
  color: rgba(255, 255, 255, 0.88);
  background: rgba(0, 0, 0, 0.14);
}

/* ============ 锚点导航 ============ */
#anchor-nav {
  padding: var(--space-md);
}

#anchor-nav h2 {
  font-size: 1.05rem;
  margin-bottom: var(--space-sm);
}

#anchor-nav ul {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
  list-style: none;
  padding: 0;
  margin: 0;
}

#anchor-nav li {
  margin: 0;
}

#anchor-nav a {
  display: inline-block;
  padding: 0.35rem 0.85rem;
  font-size: 0.84rem;
  color: var(--color-text-soft);
  border-radius: var(--radius-pill);
  background: var(--color-bg-alt);
  border: 1px solid transparent;
  transition: all var(--transition-fast);
}

#anchor-nav a:hover {
  color: #fff;
  background: var(--gradient-accent);
  border-color: transparent;
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(242, 181, 68, 0.35);
}

/* ============ 列表与内容微调 ============ */
section ul li::marker,
section ol li::marker {
  color: var(--color-primary-light);
  font-weight: 700;
}

#history ul li strong,
#howto ol li {
  color: var(--color-text);
}

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

#howto ol li {
  position: relative;
  padding: 0.6rem 0.9rem 0.6rem 2.9rem;
  margin-bottom: 0.5rem;
  background: var(--color-bg-alt);
  border-radius: var(--radius-md);
  border-left: 3px solid var(--color-primary-light);
  transition: transform var(--transition-fast), background var(--transition-fast);
}

#howto ol li::before {
  counter-increment: step;
  content: counter(step);
  position: absolute;
  left: 0.8rem;
  top: 50%;
  transform: translateY(-50%);
  width: 1.5rem;
  height: 1.5rem;
  display: grid;
  place-items: center;
  font-size: 0.8rem;
  font-weight: 700;
  color: #fff;
  border-radius: 50%;
  background: var(--gradient-accent);
}

#howto ol li:hover {
  transform: translateX(4px);
  background: #e4ecf5;
}

/* ============ 资讯文章卡片 ============ */
#news article {
  padding: var(--space-md);
  margin-bottom: var(--space-md);
  border-radius: var(--radius-md);
  background: var(--color-surface);
  border: 1px solid var(--color-border-soft);
  box-shadow: 0 4px 16px var(--color-shadow);
  transition: transform var(--transition-base), box-shadow var(--transition-base), border-color var(--transition-base);
  position: relative;
  overflow: hidden;
}

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

#news article:hover {
  transform: translateY(-4px);
  box-shadow: 0 14px 34px var(--color-shadow-strong);
  border-color: var(--color-border);
}

#news article:hover::before {
  transform: scaleY(1);
}

#news article h3 {
  margin-top: 0;
  font-size: 1.1rem;
}

#news article p {
  font-size: 0.92rem;
  margin-bottom: 0.4rem;
}

#news article a {
  font-weight: 600;
  font-size: 0.9rem;
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
}

#news article a::after {
  content: "→";
  transition: transform var(--transition-fast);
}

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

#news > div[id^="article-"] {
  padding: var(--space-md);
  margin-bottom: var(--space-sm);
  border-radius: var(--radius-md);
  background: var(--color-bg-alt);
  border: 1px dashed var(--color-border);
  transition: background var(--transition-fast);
}

#news > div[id^="article-"]:hover {
  background: #e3ebf4;
}

#news > div[id^="article-"] h3 {
  font-size: 1rem;
  margin-top: 0;
  color: var(--color-primary-dark);
}

/* ============ FAQ ============ */
#faq details {
  margin-bottom: 0.65rem;
  border-radius: var(--radius-md);
  background: var(--color-surface);
  border: 1px solid var(--color-border-soft);
  box-shadow: 0 3px 12px var(--color-shadow);
  overflow: hidden;
  transition: box-shadow var(--transition-base), border-color var(--transition-base), transform var(--transition-base);
}

#faq details:hover {
  border-color: var(--color-primary-light);
  box-shadow: 0 8px 24px var(--color-shadow-strong);
}

#faq details[open] {
  border-color: var(--color-primary-light);
  box-shadow: 0 10px 28px var(--color-shadow-strong);
}

#faq summary {
  cursor: pointer;
  padding: 0.85rem 1rem 0.85rem 2.6rem;
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--color-text);
  position: relative;
  list-style: none;
  transition: background var(--transition-fast), color var(--transition-fast);
}

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

#faq summary::before {
  content: "";
  position: absolute;
  left: 1rem;
  top: 50%;
  width: 0.55rem;
  height: 0.55rem;
  border-right: 2px solid var(--color-primary);
  border-bottom: 2px solid var(--color-primary);
  transform: translateY(-70%) rotate(-45deg);
  transition: transform var(--transition-base);
}

#faq details[open] summary::before {
  transform: translateY(-30%) rotate(45deg);
}

#faq summary:hover {
  background: rgba(43, 95, 142, 0.06);
  color: var(--color-primary-dark);
}

#faq details p {
  padding: 0 1rem 1rem 2.6rem;
  margin: 0;
  font-size: 0.92rem;
  color: var(--color-text-soft);
  animation: fadeIn 0.3s ease both;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(-4px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ============ 联系与地图 ============ */
#contact ul,
#sitemap ul,
#links ul {
  list-style: none;
  padding: 0;
  display: grid;
  gap: 0.4rem;
}

#contact ul li {
  padding: 0.55rem 0.9rem;
  border-radius: var(--radius-sm);
  background: var(--color-bg-alt);
  border-left: 3px solid var(--color-accent);
  font-size: 0.93rem;
  color: var(--color-text-soft);
  transition: transform var(--transition-fast), background var(--transition-fast);
}

#contact ul li:hover {
  transform: translateX(4px);
  background: #e3ebf4;
}

#sitemap ul,
#links ul {
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
}

#sitemap a,
#links a {
  display: block;
  padding: 0.5rem 0.85rem;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  background: var(--color-bg-alt);
  border: 1px solid transparent;
  transition: all var(--transition-fast);
}

#sitemap a:hover,
#links a:hover {
  color: #fff;
  background: var(--gradient-accent);
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(242, 181, 68, 0.32);
}

/* ============ 页脚 ============ */
footer {
  margin-top: var(--space-xl);
  padding: var(--space-xl) var(--space-md) var(--space-lg);
  background: linear-gradient(180deg, #1d4468 0%, #16334e 100%);
  color: rgba(255, 255, 255, 0.82);
  position: relative;
  overflow: hidden;
}

footer::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 15% 20%, rgba(242, 181, 68, 0.16), transparent 42%),
    radial-gradient(circle at 85% 80%, rgba(74, 127, 174, 0.28), transparent 46%);
  pointer-events: none;
}

footer > section {
  position: relative;
  max-width: var(--max-width);
  margin: 0 auto var(--space-md);
  padding-bottom: var(--space-sm);
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

footer > section:last-of-type {
  border-bottom: 0;
}

footer h2 {
  color: #fff;
  font-size: 1.02rem;
  padding-left: 0.8rem;
  margin-bottom: 0.5rem;
}

footer h2::before {
  width: 4px;
  background: var(--gradient-accent);
}

footer p {
  color: rgba(255, 255, 255, 0.72);
  font-size: 0.9rem;
  margin: 0;
}

footer > p {
  position: relative;
  max-width: var(--max-width);
  margin: var(--space-md) auto 0;
  text-align: center;
}

footer small {
  color: rgba(255, 255, 255, 0.55);
}

/* ============ 返回顶部 ============ */
#back-to-top {
  position: fixed;
  right: clamp(0.8rem, 2.5vw, 1.8rem);
  bottom: clamp(0.8rem, 2.5vw, 1.8rem);
  z-index: 90;
  padding: 0.65rem 1.15rem;
  font-family: inherit;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--color-primary-dark);
  border: 0;
  border-radius: var(--radius-pill);
  background: var(--gradient-accent);
  box-shadow: 0 8px 24px rgba(242, 181, 68, 0.45);
  cursor: pointer;
  transition: transform var(--transition-base), box-shadow var(--transition-base);
}

#back-to-top:hover {
  transform: translateY(-4px) scale(1.03);
  box-shadow: 0 14px 34px rgba(242, 181, 68, 0.6);
}

#back-to-top:active {
  transform: translateY(-1px) scale(0.99);
}

/* ============ 暗色模式 ============ */
body.dark-mode,
html.dark-mode body {
  --color-primary: #6fa8d6;
  --color-primary-dark: #a9cbe8;
  --color-primary-light: #86bce4;
  --color-accent: #f2b544;
  --color-accent-dark: #ffd27a;
  --color-bg: #0f1722;
  --color-bg-alt: #1a2534;
  --color-surface: #16202d;
  --color-surface-glass: rgba(22, 32, 45, 0.78);
  --color-text: #e6edf5;
  --color-text-soft: #b6c4d4;
  --color-text-muted: #8998a9;
  --color-border: #2a3a4d;
  --color-border-soft: rgba(111, 168, 214, 0.16);
  --color-shadow: rgba(0, 0, 0, 0.36);
  --color-shadow-strong: rgba(0, 0, 0, 0.55);
  --gradient-hero: linear-gradient(135deg, #16334e 0%, #1f4a70 45%, #8a6218 130%);
  --gradient-glass: linear-gradient(135deg, rgba(30, 44, 60, 0.86) 0%, rgba(22, 32, 45, 0.6) 100%);
  background-image:
    radial-gradient(circle at 12% 8%, rgba(111, 168, 214, 0.1), transparent 42%),
    radial-gradient(circle at 88% 0%, rgba(242, 181, 68, 0.08), transparent 38%);
}

body.dark-mode::before {
  background-image:
    linear-gradient(rgba(111, 168, 214, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(111, 168, 214, 0.05) 1px, transparent 1px);
}

body.dark-mode blockquote {
  background: var(--color-surface-glass);
}

body.dark-mode .site-search input {
  color: var(--color-text);
}

body.dark-mode #anchor-nav a {
  background: var(--color-bg-alt);
  color: var(--color-text-soft);
}

body.dark-mode #anchor-nav a:hover {
  color: #16202d;
  background: var(--gradient-accent);
}

body.dark-mode #howto ol li {
  background: var(--color-bg-alt);
  border-left-color: var(--color-primary-light);
}

body.dark-mode #howto ol li:hover {
  background: #22303f;
}

body.dark-mode #news > div[id^="article-"] {
  background: var(--color-bg-alt);
}

body.dark-mode #news > div[id^="article-"]:hover {
  background: #22303f;
}

body.dark-mode #contact ul li {
  background: var(--color-bg-alt);
}

body.dark-mode #contact ul li:hover {
  background: #22303f;
}

body.dark-mode #sitemap a,
body.dark-mode #links a {
  background: var(--color-bg-alt);
  color: var(--color-text-soft);
}

body.dark-mode #sitemap a:hover,
body.dark-mode #links a:hover {
  color: #16202d;
  background: var(--gradient-accent);
}

body.dark-mode footer {
  background: linear-gradient(180deg, #0b1420 0%, #070e16 100%);
}

body.dark-mode .btn-primary {
  color: #16202d;
}

body.dark-mode .btn-primary:hover {
  color: #16202d;
}

body.dark-mode #back-to-top {
  color: #16202d;
}

body.dark-mode #faq summary:hover {
  background: rgba(111, 168, 214, 0.1);
}

body.dark-mode #site-header {
  box-shadow: 0 4px 22px rgba(0, 0, 0, 0.4);
}

/* ============ 响应式 ============ */
@media (max-width: 1024px) {
  .nav-wrap {
    gap: var(--space-sm);
  }

  .main-nav a {
    padding: 0.35rem 0.55rem;
    font-size: 0.86rem;
  }

  .site-search {
    margin-left: 0;
  }

  .site-search input {
    min-width: 130px;
  }
}

@media (max-width: 860px) {
  :root {
    --header-offset: 96px;
  }

  .main-nav {
    display: none;
  }

  #menu-toggle {
    display: inline-block;
    margin-left: auto;
  }

  .site-search {
    order: 5;
    flex: 1 1 100%;
    margin-left: 0;
  }

  .site-search input {
    flex: 1;
    min-width: 0;
  }

  .nav-wrap {
    padding: var(--space-sm) var(--space-md);
  }

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

  main > section,
  main > nav {
    border-radius: var(--radius-md);
    padding: var(--space-md);
    margin-bottom: var(--space-md);
  }

  #hero {
    border-radius: 0 0 var(--radius-md) var(--radius-md);
    padding-top: var(--space-xl);
  }

  #hero figure {
    display: none;
  }

  .hero-actions .btn-primary,
  .hero-actions .btn-secondary {
    flex: 1 1 auto;
  }
}

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

  .top-bar {
    justify-content: center;
    text-align: center;
    gap: 0.15rem;
  }

  .brand {
    font-size: 0.92rem;
    gap: 0.45rem;
  }

  .brand span {
    max-width: 190px;
    white-space: normal;
    line-height: 1.25;
  }

  h2 {
    padding-left: 0.7rem;
  }

  .hero-actions {
    flex-direction: column;
  }

  .hero-actions .btn-primary,
  .hero-actions .btn-secondary {
    width: 100%;
  }

  #anchor-nav ul {
    gap: 0.35rem;
  }

  #anchor-nav a {
    font-size: 0.78rem;
    padding: 0.3rem 0.7rem;
  }

  #faq summary {
    font-size: 0.9rem;
    padding: 0.75rem 0.85rem 0.75rem 2.4rem;
  }

  #faq summary::before {
    left: 0.9rem;
  }

  #faq details p {
    padding: 0 0.85rem 0.85rem 2.4rem;
    font-size: 0.88rem;
  }

  #sitemap ul,
  #links ul {
    grid-template-columns: 1fr 1fr;
  }

  #back-to-top {
    padding: 0.55rem 0.95rem;
    font-size: 0.78rem;
  }

  footer {
    padding-bottom: 4.5rem;
  }
}

@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;
  }
}

@media print {
  #site-header,
  #anchor-nav,
  #back-to-top,
  #hero figure,
  footer,
  .hero-actions {
    display: none !important;
  }

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

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