:root {
  --bg: #f4f7ff;
  --bg-soft: #e9eefc;
  --surface: #ffffff;
  --surface-glass: rgba(255, 255, 255, 0.72);
  --surface-glass-strong: rgba(255, 255, 255, 0.9);
  --text: #101a33;
  --text-soft: #45527a;
  --text-muted: #6b7899;
  --line: rgba(21, 40, 90, 0.12);
  --line-strong: rgba(21, 40, 90, 0.2);
  --brand: #0d1b3e;
  --brand-2: #1f3a7a;
  --accent: #4cc9f0;
  --accent-2: #7b61ff;
  --gold: #ffd166;
  --danger: #e5484d;
  --radius-lg: 24px;
  --radius-md: 16px;
  --radius-sm: 10px;
  --shadow-sm: 0 2px 8px rgba(13, 27, 62, 0.06);
  --shadow-md: 0 12px 32px rgba(13, 27, 62, 0.1);
  --shadow-lg: 0 24px 64px rgba(13, 27, 62, 0.16);
  --grad-hero: linear-gradient(135deg, #0d1b3e 0%, #1f3a7a 45%, #2d5fd0 100%);
  --grad-accent: linear-gradient(120deg, #4cc9f0 0%, #7b61ff 100%);
  --grad-gold: linear-gradient(120deg, #ffd166 0%, #ff9f43 100%);
  --grad-card: linear-gradient(160deg, rgba(255, 255, 255, 0.95), rgba(233, 238, 252, 0.85));
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  --header-h: 72px;
  --maxw: 1200px;
}

html[data-theme="dark"],
html.dark-mode,
body.dark-mode {
  --bg: #070d1d;
  --bg-soft: #0c1530;
  --surface: #101a33;
  --surface-glass: rgba(16, 26, 51, 0.7);
  --surface-glass-strong: rgba(16, 26, 51, 0.9);
  --text: #eaf0ff;
  --text-soft: #b6c2e2;
  --text-muted: #8492b8;
  --line: rgba(140, 165, 230, 0.16);
  --line-strong: rgba(140, 165, 230, 0.28);
  --brand: #eaf0ff;
  --brand-2: #b6c2e2;
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.4);
  --shadow-md: 0 12px 32px rgba(0, 0, 0, 0.5);
  --shadow-lg: 0 24px 64px rgba(0, 0, 0, 0.6);
  --grad-hero: linear-gradient(135deg, #070d1d 0%, #101a33 45%, #1f3a7a 100%);
  --grad-card: linear-gradient(160deg, rgba(16, 26, 51, 0.95), rgba(12, 21, 48, 0.85));
}

*,
*::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: 1.8;
  color: var(--text);
  background: var(--bg);
  background-image:
    radial-gradient(1200px 600px at 10% -10%, rgba(76, 201, 240, 0.12), transparent 60%),
    radial-gradient(900px 500px at 100% 0%, rgba(123, 97, 255, 0.12), 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(--accent-2);
  text-decoration: none;
  transition: color 0.2s var(--ease), opacity 0.2s var(--ease);
}

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

h1, h2, h3, h4, h5, h6 {
  margin: 0 0 0.6em;
  line-height: 1.35;
  font-weight: 700;
  color: var(--text);
  letter-spacing: 0.01em;
}

h1 {
  font-size: clamp(1.6rem, 3.6vw, 2.6rem);
  line-height: 1.3;
}

h2 {
  font-size: clamp(1.35rem, 2.6vw, 2rem);
  padding-left: 16px;
  position: relative;
}

h2::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.18em;
  bottom: 0.18em;
  width: 5px;
  border-radius: 4px;
  background: var(--grad-accent);
}

h3 {
  font-size: clamp(1.1rem, 1.8vw, 1.35rem);
}

h4 {
  font-size: clamp(1rem, 1.4vw, 1.12rem);
  color: var(--text-soft);
}

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

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

li {
  margin-bottom: 0.45em;
}

li::marker {
  color: var(--accent);
}

strong {
  color: var(--text);
  font-weight: 700;
}

time {
  color: var(--text-muted);
  font-size: 0.88em;
}

blockquote {
  margin: 0 0 1.2em;
  padding: 18px 22px;
  background: var(--surface-glass);
  border-left: 4px solid var(--accent);
  border-radius: var(--radius-md);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  box-shadow: var(--shadow-sm);
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease);
}

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

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

address {
  font-style: normal;
}

button {
  font-family: inherit;
  cursor: pointer;
}

input {
  font-family: inherit;
}

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

/* ============ Header ============ */
#site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--surface-glass);
  backdrop-filter: blur(18px) saturate(160%);
  -webkit-backdrop-filter: blur(18px) saturate(160%);
  border-bottom: 1px solid var(--line);
  box-shadow: 0 4px 24px rgba(13, 27, 62, 0.06);
  transition: background 0.3s var(--ease), box-shadow 0.3s var(--ease);
}

.header-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 24px;
  height: var(--header-h);
  display: flex;
  align-items: center;
  gap: 20px;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
  color: var(--text);
  font-weight: 800;
}

.brand-logo svg {
  border-radius: 12px;
  box-shadow: 0 4px 14px rgba(76, 201, 240, 0.35);
  transition: transform 0.4s var(--ease);
}

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

.brand-name {
  font-size: 1.15rem;
  letter-spacing: 0.04em;
  background: var(--grad-accent);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

#main-nav {
  flex: 1;
  min-width: 0;
}

#main-nav ul {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  list-style: none;
  margin: 0;
  padding: 0;
}

#main-nav a {
  display: block;
  padding: 8px 12px;
  font-size: 0.92rem;
  color: var(--text-soft);
  border-radius: 999px;
  white-space: nowrap;
  transition: background 0.25s var(--ease), color 0.25s var(--ease), transform 0.25s var(--ease);
}

#main-nav a:hover,
#main-nav a:focus-visible {
  background: var(--grad-accent);
  color: #fff;
  transform: translateY(-2px);
}

.header-tools {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}

.header-tools form {
  display: flex;
  align-items: center;
  gap: 0;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 999px;
  overflow: hidden;
  transition: border-color 0.25s var(--ease), box-shadow 0.25s var(--ease);
}

.header-tools form:focus-within {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(76, 201, 240, 0.2);
}

#site-search {
  border: 0;
  background: transparent;
  padding: 8px 6px 8px 16px;
  font-size: 0.88rem;
  color: var(--text);
  width: 150px;
  outline: none;
}

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

.header-tools form button {
  border: 0;
  background: var(--grad-accent);
  color: #fff;
  padding: 8px 16px;
  font-size: 0.85rem;
  font-weight: 600;
  transition: filter 0.25s var(--ease);
}

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

#theme-toggle,
#menu-toggle {
  border: 1px solid var(--line-strong);
  background: var(--surface);
  color: var(--text);
  padding: 8px 14px;
  border-radius: 999px;
  font-size: 0.85rem;
  font-weight: 600;
  transition: background 0.25s var(--ease), color 0.25s var(--ease), transform 0.25s var(--ease), border-color 0.25s var(--ease);
}

#theme-toggle:hover,
#menu-toggle:hover {
  background: var(--grad-accent);
  color: #fff;
  border-color: transparent;
  transform: translateY(-2px);
}

#menu-toggle {
  display: none;
}

/* ============ Main layout ============ */
main {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 24px 80px;
  display: block;
}

main > section {
  margin: 56px 0;
  padding: 32px;
  background: var(--surface-glass);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  backdrop-filter: blur(14px) saturate(150%);
  -webkit-backdrop-filter: blur(14px) saturate(150%);
  box-shadow: var(--shadow-sm);
  transition: box-shadow 0.4s var(--ease), transform 0.4s var(--ease), border-color 0.4s var(--ease);
  animation: fadeUp 0.8s var(--ease) both;
}

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

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

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes pulseGlow {
  0%, 100% { box-shadow: 0 0 0 0 rgba(76, 201, 240, 0.4); }
  50% { box-shadow: 0 0 0 12px rgba(76, 201, 240, 0); }
}

/* ============ Hero ============ */
#hero {
  margin-top: 32px;
  padding: 0;
  background: transparent;
  border: 0;
  box-shadow: none;
  backdrop-filter: none;
  -webkit-backdrop-filter: none;
}

#hero:hover {
  box-shadow: none;
}

.breadcrumb {
  margin-bottom: 20px;
}

.breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  list-style: none;
  margin: 0;
  padding: 0;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.breadcrumb li + li::before {
  content: "/";
  margin-right: 8px;
  color: var(--text-muted);
}

.breadcrumb a {
  color: var(--text-soft);
}

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

#hero-title {
  background: var(--grad-hero);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  margin-bottom: 18px;
}

.hero-lead {
  font-size: 1.05rem;
  color: var(--text-soft);
  max-width: 900px;
  margin-bottom: 32px;
}

.hero-banner {
  position: relative;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
  background: var(--grad-hero);
  aspect-ratio: 1200 / 420;
  min-height: 220px;
  isolation: isolate;
}

.banner-slide {
  position: absolute;
  inset: 0;
  margin: 0;
  opacity: 0;
  transform: scale(1.04);
  transition: opacity 0.8s var(--ease), transform 0.8s var(--ease);
  pointer-events: none;
}

.banner-slide:first-child {
  opacity: 1;
  transform: scale(1);
  pointer-events: auto;
}

.banner-slide svg {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.banner-slide figcaption {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  padding: 40px 24px 18px;
  background: linear-gradient(to top, rgba(7, 13, 29, 0.85), transparent);
  color: #fff;
  font-size: 0.9rem;
  letter-spacing: 0.02em;
}

.banner-controls {
  position: absolute;
  right: 18px;
  bottom: 18px;
  display: flex;
  gap: 8px;
  z-index: 5;
}

.banner-controls button {
  width: 34px;
  height: 34px;
  border-radius: 50%;
  border: 1px solid rgba(255, 255, 255, 0.4);
  background: rgba(255, 255, 255, 0.18);
  color: #fff;
  font-size: 0.85rem;
  font-weight: 700;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  transition: background 0.25s var(--ease), transform 0.25s var(--ease);
}

.banner-controls button:hover,
.banner-controls button:focus-visible {
  background: var(--grad-accent);
  transform: scale(1.1);
}

.hero-stats {
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}

.hero-stats li {
  margin: 0;
  padding: 20px 16px;
  text-align: center;
  background: var(--surface-glass-strong);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  box-shadow: var(--shadow-sm);
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease), border-color 0.3s var(--ease);
}

.hero-stats li:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-md);
  border-color: var(--accent);
}

.hero-stats .num-anim {
  display: block;
  font-size: clamp(1.6rem, 3vw, 2.2rem);
  font-weight: 800;
  line-height: 1.1;
  background: var(--grad-accent);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  font-variant-numeric: tabular-nums;
}

.hero-stats span {
  display: block;
  margin-top: 6px;
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* ============ Anchor nav ============ */
#anchor-nav {
  margin: 40px 0;
  padding: 20px 24px;
  background: var(--surface-glass);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  animation: fadeUp 0.8s var(--ease) both;
}

#anchor-nav h2 {
  font-size: 1rem;
  margin-bottom: 12px;
  padding-left: 14px;
}

#anchor-nav h2::before {
  width: 4px;
}

#anchor-nav ul {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  list-style: none;
  margin: 0;
  padding: 0;
}

#anchor-nav li {
  margin: 0;
}

#anchor-nav a {
  display: inline-block;
  padding: 6px 14px;
  font-size: 0.85rem;
  color: var(--text-soft);
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 999px;
  transition: all 0.25s var(--ease);
}

#anchor-nav a:hover,
#anchor-nav a:focus-visible {
  background: var(--grad-accent);
  color: #fff;
  border-color: transparent;
  transform: translateY(-2px);
  box-shadow: 0 6px 18px rgba(76, 201, 240, 0.3);
}

/* ============ Content typography ============ */
main > section > h3 {
  margin-top: 1.6em;
  padding-bottom: 8px;
  border-bottom: 1px dashed var(--line-strong);
}

main > section > h3:first-of-type {
  margin-top: 1em;
}

main > section h4 {
  margin-top: 1.4em;
  color: var(--text);
}

main > section h4::before {
  content: "▸ ";
  color: var(--accent);
}

/* ============ Articles ============ */
#articles > article {
  margin: 0 0 20px;
  padding: 22px 24px;
  background: var(--grad-card);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  transition: transform 0.35s var(--ease), box-shadow 0.35s var(--ease), border-color 0.35s var(--ease);
  position: relative;
  overflow: hidden;
}

#articles > article::after {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 4px;
  background: var(--grad-accent);
  transform: scaleY(0);
  transform-origin: top;
  transition: transform 0.35s var(--ease);
}

#articles > article:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: var(--line-strong);
}

#articles > article:hover::after {
  transform: scaleY(1);
}

#articles > article h3 {
  margin: 0 0 8px;
  font-size: 1.08rem;
}

#articles > article h3 a {
  color: var(--text);
  background-image: linear-gradient(var(--accent), var(--accent));
  background-size: 0% 2px;
  background-repeat: no-repeat;
  background-position: 0 100%;
  transition: background-size 0.35s var(--ease), color 0.25s var(--ease);
}

#articles > article h3 a:hover {
  color: var(--accent-2);
  background-size: 100% 2px;
}

#articles > article > p {
  margin: 6px 0;
  font-size: 0.92rem;
}

#articles > article > p:last-child a {
  display: inline-block;
  font-weight: 600;
  font-size: 0.88rem;
  padding: 4px 14px;
  border-radius: 999px;
  background: var(--grad-accent);
  color: #fff;
  transition: filter 0.25s var(--ease), transform 0.25s var(--ease);
}

#articles > article > p:last-child a:hover {
  filter: brightness(1.1);
  transform: translateX(4px);
}

#articles section[id^="article-"] {
  margin: 24px 0 0;
  padding: 24px;
  background: var(--surface-glass);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}

#articles section[id$="-full"] h4 {
  margin-top: 0;
  color: var(--accent-2);
}

/* ============ News ============ */
#news article {
  margin: 0 0 18px;
  padding: 20px 22px;
  background: var(--surface-glass);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease);
}

#news article:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
}

#news article h3 {
  margin-top: 0;
  font-size: 1.05rem;
}

#news article p {
  font-size: 0.92rem;
  margin-bottom: 0;
}

/* ============ FAQ ============ */
#faq details {
  margin: 0 0 12px;
  padding: 0;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  overflow: hidden;
  transition: border-color 0.3s var(--ease), box-shadow 0.3s var(--ease), transform 0.3s var(--ease);
}

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

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

#faq summary {
  position: relative;
  padding: 16px 48px 16px 20px;
  font-weight: 600;
  color: var(--text);
  cursor: pointer;
  list-style: none;
  transition: background 0.25s var(--ease), color 0.25s var(--ease);
}

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

#faq summary::after {
  content: "+";
  position: absolute;
  right: 18px;
  top: 50%;
  transform: translateY(-50%);
  width: 26px;
  height: 26px;
  line-height: 24px;
  text-align: center;
  border-radius: 50%;
  background: var(--grad-accent);
  color: #fff;
  font-size: 1.1rem;
  font-weight: 700;
  transition: transform 0.35s var(--ease), background 0.35s var(--ease);
}

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

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

#faq details p {
  margin: 0;
  padding: 0 20px 18px;
  font-size: 0.95rem;
  color: var(--text-soft);
  animation: fadeIn 0.4s var(--ease);
}

/* ============ Contact ============ */
#contact address {
  padding: 22px 24px;
  background: var(--grad-card);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  margin-bottom: 20px;
}

#contact address p {
  margin: 0 0 8px;
  font-size: 0.95rem;
}

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

#contact address a {
  font-weight: 600;
  border-bottom: 1px dashed var(--accent);
}

/* ============ Sitemap & links ============ */
#sitemap ul,
#links ul {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  list-style: none;
  padding: 0;
  margin: 0 0 12px;
}

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

#sitemap a,
#links a {
  display: inline-block;
  padding: 6px 14px;
  font-size: 0.88rem;
  color: var(--text-soft);
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 999px;
  transition: all 0.25s var(--ease);
}

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

/* ============ Footer ============ */
#site-footer {
  margin-top: 40px;
  background: var(--grad-hero);
  color: rgba(255, 255, 255, 0.82);
  border-top: 1px solid var(--line);
  position: relative;
  overflow: hidden;
}

#site-footer::before {
  content: "";
  position: absolute;
  top: -120px;
  right: -120px;
  width: 360px;
  height: 360px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(76, 201, 240, 0.25), transparent 70%);
  pointer-events: none;
}

.footer-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 56px 24px 32px;
  display: grid;
  grid-template-columns: 1.6fr 1fr 1fr 1.2fr;
  gap: 32px;
  position: relative;
  z-index: 1;
}

.footer-inner h2 {
  font-size: 1.05rem;
  color: #fff;
  padding-left: 0;
  margin-bottom: 14px;
}

.footer-inner h2::before {
  display: none;
}

.footer-inner p {
  color: rgba(255, 255, 255, 0.7);
  font-size: 0.88rem;
  margin: 0 0 8px;
}

.footer-inner ul {
  list-style: none;
  margin: 0;
  padding: 0;
}

.footer-inner li {
  margin-bottom: 8px;
}

.footer-inner a {
  color: rgba(255, 255, 255, 0.78);
  font-size: 0.9rem;
  transition: color 0.25s var(--ease), padding-left 0.25s var(--ease);
}

.footer-inner a:hover {
  color: var(--gold);
  padding-left: 4px;
}

.footer-inner time {
  color: var(--gold);
}

.footer-bottom {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 20px 24px 32px;
  border-top: 1px solid rgba(255, 255, 255, 0.12);
  text-align: center;
  position: relative;
  z-index: 1;
}

.footer-bottom p {
  color: rgba(255, 255, 255, 0.55);
  font-size: 0.82rem;
  margin: 0 0 4px;
}

/* ============ Back to top ============ */
#back-to-top {
  position: fixed;
  right: 24px;
  bottom: 24px;
  z-index: 90;
  padding: 12px 18px;
  border: 0;
  border-radius: 999px;
  background: var(--grad-accent);
  color: #fff;
  font-size: 0.85rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  box-shadow: 0 10px 28px rgba(76, 201, 240, 0.4);
  opacity: 0;
  visibility: hidden;
  transform: translateY(16px);
  transition: opacity 0.35s var(--ease), transform 0.35s var(--ease), visibility 0.35s var(--ease), filter 0.25s var(--ease);
}

#back-to-top:hover {
  filter: brightness(1.1);
  transform: translateY(-4px);
}

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

/* ============ Scroll animations ============ */
main > section,
#anchor-nav,
#articles > article,
#news article,
#faq details,
#hero .hero-stats li {
  will-change: transform, opacity;
}

@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;
  }
}

/* ============ Responsive ============ */
@media (max-width: 1100px) {
  .header-inner {
    gap: 12px;
  }

  #main-nav a {
    padding: 8px 9px;
    font-size: 0.86rem;
  }

  #site-search {
    width: 120px;
  }

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

@media (max-width: 900px) {
  :root {
    --header-h: 64px;
  }

  .header-inner {
    flex-wrap: wrap;
    height: auto;
    padding: 10px 16px;
    gap: 10px;
  }

  #main-nav {
    order: 3;
    flex-basis: 100%;
    display: none;
  }

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

  #main-nav ul {
    flex-direction: column;
    gap: 2px;
    padding: 8px 0;
    border-top: 1px solid var(--line);
  }

  #main-nav a {
    border-radius: var(--radius-sm);
    padding: 10px 14px;
  }

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

  .header-tools {
    margin-left: auto;
  }

  .header-tools form {
    display: none;
  }

  main {
    padding: 0 16px 56px;
  }

  main > section {
    margin: 32px 0;
    padding: 22px 18px;
    border-radius: var(--radius-md);
  }

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

  .hero-banner {
    min-height: 180px;
  }

  .banner-slide figcaption {
    font-size: 0.8rem;
    padding: 30px 16px 14px;
  }

  #anchor-nav {
    padding: 16px;
  }

  .footer-inner {
    grid-template-columns: 1fr;
    gap: 24px;
    padding: 40px 16px 24px;
  }

  .footer-bottom {
    padding: 16px 16px 28px;
  }

  #back-to-top {
    right: 14px;
    bottom: 14px;
    padding: 10px 14px;
    font-size: 0.78rem;
  }
}

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

  h1 {
    font-size: 1.45rem;
  }

  h2 {
    font-size: 1.2rem;
    padding-left: 12px;
  }

  h2::before {
    width: 4px;
  }

  .brand-name {
    font-size: 1rem;
  }

  .hero-lead {
    font-size: 0.95rem;
  }

  .hero-stats {
    gap: 10px;
  }

  .hero-stats li {
    padding: 14px 10px;
  }

  .hero-stats .num-anim {
    font-size: 1.5rem;
  }

  .hero-stats span {
    font-size: 0.76rem;
  }

  .banner-controls {
    right: 10px;
    bottom: 10px;
    gap: 6px;
  }

  .banner-controls button {
    width: 28px;
    height: 28px;
    font-size: 0.75rem;
  }

  #articles > article {
    padding: 16px;
  }

  #faq summary {
    padding: 14px 44px 14px 16px;
    font-size: 0.94rem;
  }

  #faq details p {
    padding: 0 16px 16px;
    font-size: 0.9rem;
  }

  #contact address {
    padding: 16px;
  }

  blockquote {
    padding: 14px 16px;
  }
}

/* ============ Print ============ */
@media print {
  #site-header,
  #back-to-top,
  #anchor-nav,
  .banner-controls,
  #site-footer {
    display: none !important;
  }

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

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