:root {
  --bg: #f4f6fb;
  --bg-soft: #ffffff;
  --bg-elevated: rgba(255, 255, 255, 0.72);
  --text: #1a1a2e;
  --text-soft: #4a4a63;
  --text-muted: #7a7a92;
  --border: rgba(26, 26, 46, 0.1);
  --border-strong: rgba(26, 26, 46, 0.18);
  --brand: #f2a900;
  --brand-2: #ff6b6b;
  --brand-3: #7c5cff;
  --accent: #00c2a8;
  --grad-hero: linear-gradient(135deg, #1a1a2e 0%, #2d2b55 45%, #4b3f8f 100%);
  --grad-brand: linear-gradient(135deg, #f2a900 0%, #ff6b6b 100%);
  --grad-soft: linear-gradient(135deg, rgba(242, 169, 0, 0.12), rgba(124, 92, 255, 0.12));
  --shadow-sm: 0 2px 8px rgba(26, 26, 46, 0.06);
  --shadow-md: 0 8px 28px rgba(26, 26, 46, 0.1);
  --shadow-lg: 0 18px 48px rgba(26, 26, 46, 0.16);
  --radius-sm: 10px;
  --radius: 16px;
  --radius-lg: 24px;
  --radius-pill: 999px;
  --glass-bg: rgba(255, 255, 255, 0.55);
  --glass-border: rgba(255, 255, 255, 0.6);
  --glass-blur: blur(16px) saturate(160%);
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
  --header-h: 72px;
  --maxw: 1180px;
}

html[data-theme="dark"] {
  --bg: #0f0f1a;
  --bg-soft: #171728;
  --bg-elevated: rgba(23, 23, 40, 0.72);
  --text: #f0f0f7;
  --text-soft: #c3c3d6;
  --text-muted: #8f8fa8;
  --border: rgba(255, 255, 255, 0.1);
  --border-strong: rgba(255, 255, 255, 0.2);
  --grad-hero: linear-gradient(135deg, #0b0b16 0%, #1d1b38 50%, #332a5c 100%);
  --grad-soft: linear-gradient(135deg, rgba(242, 169, 0, 0.16), rgba(124, 92, 255, 0.18));
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.4);
  --shadow-md: 0 8px 28px rgba(0, 0, 0, 0.45);
  --shadow-lg: 0 18px 48px rgba(0, 0, 0, 0.55);
  --glass-bg: rgba(23, 23, 40, 0.55);
  --glass-border: rgba(255, 255, 255, 0.12);
}

* {
  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: var(--bg);
  background-image: radial-gradient(
      circle at 12% 8%,
      rgba(242, 169, 0, 0.1),
      transparent 42%
    ),
    radial-gradient(circle at 88% 4%, rgba(124, 92, 255, 0.12), transparent 46%),
    radial-gradient(circle at 50% 100%, rgba(0, 194, 168, 0.08), transparent 50%);
  background-attachment: fixed;
  transition: background-color 0.4s var(--ease), color 0.4s var(--ease);
  overflow-x: hidden;
}

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

a {
  color: var(--brand-3);
  text-decoration: none;
  transition: color 0.25s var(--ease), opacity 0.25s var(--ease);
}

a:hover,
a:focus-visible {
  color: var(--brand-2);
}

:focus-visible {
  outline: 3px solid rgba(124, 92, 255, 0.6);
  outline-offset: 2px;
  border-radius: 6px;
}

h1,
h2,
h3,
h4 {
  line-height: 1.3;
  color: var(--text);
  letter-spacing: -0.01em;
  scroll-margin-top: calc(var(--header-h) + 24px);
}

h1 {
  font-size: clamp(1.7rem, 4vw, 2.6rem);
  margin: 0 0 0.6em;
}

h2 {
  font-size: clamp(1.4rem, 2.8vw, 1.9rem);
  margin: 0 0 0.7em;
  position: relative;
  padding-left: 18px;
}

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

h3 {
  font-size: clamp(1.1rem, 2vw, 1.3rem);
  margin: 1.6em 0 0.5em;
}

h4 {
  font-size: 1.02rem;
  margin: 1.4em 0 0.4em;
  color: var(--text-soft);
}

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

ul,
ol {
  margin: 0 0 1em;
  padding-left: 1.3em;
  color: var(--text-soft);
}

li {
  margin-bottom: 0.35em;
}

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

blockquote {
  margin: 1.2em 0;
  padding: 1em 1.2em;
  border-left: 4px solid var(--brand);
  border-radius: var(--radius-sm);
  background: var(--glass-bg);
  -webkit-backdrop-filter: var(--glass-blur);
  backdrop-filter: var(--glass-blur);
  border: 1px solid var(--glass-border);
  border-left: 4px solid var(--brand);
}

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

.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;
}

/* ===== Header ===== */
#site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--glass-bg);
  -webkit-backdrop-filter: var(--glass-blur);
  backdrop-filter: var(--glass-blur);
  border-bottom: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
  transition: background 0.4s var(--ease), box-shadow 0.4s var(--ease);
}

.header-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 10px 20px;
  display: flex;
  align-items: center;
  gap: 16px;
  min-height: var(--header-h);
}

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

.brand svg {
  border-radius: 12px;
  box-shadow: var(--shadow-sm);
  transition: transform 0.4s var(--ease);
}

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

.brand-text {
  font-weight: 700;
  font-size: 0.98rem;
  letter-spacing: 0.01em;
  background: var(--grad-brand);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  white-space: nowrap;
}

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

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

#main-nav li {
  margin: 0;
}

#main-nav a {
  display: inline-block;
  padding: 6px 11px;
  font-size: 0.86rem;
  color: var(--text-soft);
  border-radius: var(--radius-pill);
  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-soft);
  color: var(--text);
  transform: translateY(-2px);
}

.header-tools {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-shrink: 0;
}

#site-search {
  display: flex;
  align-items: center;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius-pill);
  overflow: hidden;
  transition: border-color 0.25s var(--ease), box-shadow 0.25s var(--ease);
}

#site-search:focus-within {
  border-color: var(--brand-3);
  box-shadow: 0 0 0 3px rgba(124, 92, 255, 0.18);
}

#search-input {
  border: 0;
  background: transparent;
  padding: 7px 12px;
  font-size: 0.85rem;
  color: var(--text);
  width: 160px;
  outline: none;
  font-family: inherit;
}

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

#site-search button[type="submit"] {
  border: 0;
  background: var(--grad-brand);
  color: #fff;
  padding: 7px 14px;
  font-size: 0.82rem;
  font-weight: 600;
  cursor: pointer;
  font-family: inherit;
  transition: filter 0.25s var(--ease);
}

#site-search button[type="submit"]:hover {
  filter: brightness(1.08);
}

#theme-toggle,
#menu-toggle {
  border: 1px solid var(--border-strong);
  background: var(--bg-elevated);
  color: var(--text);
  padding: 7px 14px;
  border-radius: var(--radius-pill);
  font-size: 0.82rem;
  font-weight: 600;
  cursor: pointer;
  font-family: inherit;
  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-brand);
  color: #fff;
  border-color: transparent;
  transform: translateY(-2px);
}

#menu-toggle {
  display: none;
}

/* ===== Main / Sections ===== */
main {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 20px 40px;
  display: block;
}

main > section {
  margin: 40px 0;
  padding: 28px clamp(18px, 3vw, 36px);
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  -webkit-backdrop-filter: var(--glass-blur);
  backdrop-filter: var(--glass-blur);
  transition: box-shadow 0.35s var(--ease), transform 0.35s var(--ease),
    border-color 0.35s var(--ease);
  animation: fadeUp 0.7s var(--ease) both;
}

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

main > section#hero,
main > section#sitemap,
main > section#links {
  background: transparent;
  border: 0;
  box-shadow: none;
  -webkit-backdrop-filter: none;
  backdrop-filter: none;
  padding-left: 0;
  padding-right: 0;
}

main > section#hero:hover,
main > section#sitemap:hover,
main > section#links:hover {
  box-shadow: none;
}

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

/* ===== Hero ===== */
#hero {
  margin-top: 24px !important;
}

.hero-slider {
  position: relative;
  border-radius: var(--radius-lg);
  background: var(--grad-hero);
  color: #fff;
  padding: clamp(28px, 5vw, 56px) clamp(22px, 5vw, 60px) clamp(56px, 8vw, 80px);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
  isolation: isolate;
}

.hero-slider::before {
  content: "";
  position: absolute;
  inset: -40% -10% auto auto;
  width: 520px;
  height: 520px;
  background: radial-gradient(circle, rgba(242, 169, 0, 0.4), transparent 62%);
  filter: blur(10px);
  z-index: -1;
  animation: floaty 12s ease-in-out infinite;
}

.hero-slider::after {
  content: "";
  position: absolute;
  inset: auto auto -40% -12%;
  width: 460px;
  height: 460px;
  background: radial-gradient(circle, rgba(124, 92, 255, 0.5), transparent 64%);
  filter: blur(10px);
  z-index: -1;
  animation: floaty 16s ease-in-out infinite reverse;
}

@keyframes floaty {
  0%,
  100% {
    transform: translate3d(0, 0, 0) scale(1);
  }
  50% {
    transform: translate3d(-24px, 26px, 0) scale(1.08);
  }
}

.hero-slider .slide {
  display: none;
  max-width: 760px;
  animation: fadeUp 0.6s var(--ease) both;
}

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

.hero-slider .slide h1,
.hero-slider .slide h2 {
  color: #fff;
  padding-left: 0;
}

.hero-slider .slide h1::before,
.hero-slider .slide h2::before {
  display: none;
}

.hero-slider .slide h1 {
  font-size: clamp(1.6rem, 4.4vw, 2.7rem);
  text-shadow: 0 2px 24px rgba(0, 0, 0, 0.3);
}

.hero-slider .slide h2 {
  font-size: clamp(1.4rem, 3.4vw, 2.1rem);
}

.hero-slider .slide p {
  color: rgba(255, 255, 255, 0.86);
  font-size: clamp(0.95rem, 1.6vw, 1.08rem);
  max-width: 62ch;
}

.cta {
  display: inline-block;
  margin-top: 8px;
  padding: 12px 26px;
  border-radius: var(--radius-pill);
  background: var(--grad-brand);
  color: #fff !important;
  font-weight: 700;
  font-size: 0.92rem;
  box-shadow: 0 10px 24px rgba(242, 169, 0, 0.35);
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease),
    filter 0.3s var(--ease);
}

.cta:hover,
.cta:focus-visible {
  transform: translateY(-3px) scale(1.02);
  box-shadow: 0 16px 34px rgba(242, 169, 0, 0.45);
  filter: brightness(1.05);
}

.slider-controls {
  position: absolute;
  right: clamp(18px, 4vw, 40px);
  bottom: clamp(18px, 4vw, 32px);
  display: flex;
  gap: 10px;
  z-index: 2;
}

.slider-controls button {
  width: 42px;
  height: 42px;
  border-radius: 50%;
  border: 1px solid rgba(255, 255, 255, 0.35);
  background: rgba(255, 255, 255, 0.14);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  color: #fff;
  font-size: 1.4rem;
  line-height: 1;
  cursor: pointer;
  display: grid;
  place-items: center;
  transition: background 0.25s var(--ease), transform 0.25s var(--ease);
}

.slider-controls button:hover {
  background: rgba(255, 255, 255, 0.3);
  transform: scale(1.08);
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
  margin-top: -34px;
  padding: 0 clamp(10px, 3vw, 28px);
  position: relative;
  z-index: 3;
}

.hero-stats .stat {
  background: var(--glass-bg);
  -webkit-backdrop-filter: var(--glass-blur);
  backdrop-filter: var(--glass-blur);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius);
  padding: 16px 12px;
  text-align: center;
  box-shadow: var(--shadow-md);
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease);
}

.hero-stats .stat:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
}

.hero-stats .num {
  display: block;
  font-size: clamp(1.3rem, 3vw, 1.9rem);
  font-weight: 800;
  background: var(--grad-brand);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  font-variant-numeric: tabular-nums;
}

.hero-stats .label {
  display: block;
  font-size: 0.78rem;
  color: var(--text-muted);
  margin-top: 2px;
}

/* ===== Breadcrumb ===== */
#breadcrumb {
  margin: 18px 0 0;
}

#breadcrumb ol {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  padding: 0;
  margin: 0;
  font-size: 0.84rem;
  color: var(--text-muted);
}

#breadcrumb li {
  margin: 0;
  display: flex;
  align-items: center;
  gap: 6px;
}

#breadcrumb li + li::before {
  content: "›";
  color: var(--text-muted);
  opacity: 0.7;
}

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

#breadcrumb a:hover {
  color: var(--brand);
}

/* ===== Anchor nav ===== */
#anchor-nav {
  margin: 16px 0 8px;
  padding: 10px;
  background: var(--glass-bg);
  -webkit-backdrop-filter: var(--glass-blur);
  backdrop-filter: var(--glass-blur);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow-x: auto;
  scrollbar-width: thin;
  -webkit-overflow-scrolling: touch;
}

#anchor-nav ul {
  list-style: none;
  display: flex;
  gap: 6px;
  margin: 0;
  padding: 0;
  flex-wrap: nowrap;
}

#anchor-nav li {
  margin: 0;
  flex-shrink: 0;
}

#anchor-nav a {
  display: inline-block;
  padding: 6px 14px;
  border-radius: var(--radius-pill);
  font-size: 0.82rem;
  color: var(--text-soft);
  border: 1px solid var(--border);
  background: var(--bg-soft);
  white-space: nowrap;
  transition: all 0.25s var(--ease);
}

#anchor-nav a:hover {
  background: var(--grad-brand);
  color: #fff;
  border-color: transparent;
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(242, 169, 0, 0.3);
}

/* ===== Articles / News / Cases cards ===== */
#articles article,
#news article {
  background: var(--bg-soft);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px 20px;
  margin-bottom: 14px;
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease),
    border-color 0.3s var(--ease);
}

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

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

#articles article p,
#news article p {
  margin-bottom: 0.5em;
  font-size: 0.92rem;
}

#articles article a[href^="#article-"] {
  display: inline-block;
  font-size: 0.85rem;
  font-weight: 600;
  padding: 4px 12px;
  border-radius: var(--radius-pill);
  background: var(--grad-soft);
  color: var(--brand-3);
  transition: all 0.25s var(--ease);
}

#articles article a[href^="#article-"]:hover {
  background: var(--grad-brand);
  color: #fff;
  transform: translateX(4px);
}

#articles div[id^="article-"] {
  background: var(--glass-bg);
  -webkit-backdrop-filter: var(--glass-blur);
  backdrop-filter: var(--glass-blur);
  border: 1px solid var(--border);
  border-left: 4px solid var(--brand-3);
  border-radius: var(--radius);
  padding: 18px 22px;
  margin: 18px 0;
  scroll-margin-top: calc(var(--header-h) + 24px);
  animation: fadeUp 0.6s var(--ease) both;
}

#articles div[id^="article-"] h4 {
  margin-top: 0;
  color: var(--text);
  font-size: 1rem;
}

/* ===== FAQ ===== */
#faq details {
  background: var(--bg-soft);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 4px 18px;
  margin-bottom: 10px;
  transition: box-shadow 0.3s var(--ease), border-color 0.3s var(--ease),
    background 0.3s var(--ease);
}

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

#faq details[open] {
  box-shadow: var(--shadow-md);
  border-color: rgba(242, 169, 0, 0.45);
  background: var(--grad-soft), var(--bg-soft);
}

#faq summary {
  cursor: pointer;
  font-weight: 600;
  padding: 14px 0;
  list-style: none;
  position: relative;
  padding-right: 30px;
  color: var(--text);
  transition: color 0.25s var(--ease);
  font-size: 0.95rem;
}

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

#faq summary::after {
  content: "+";
  position: absolute;
  right: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 24px;
  height: 24px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  background: var(--grad-soft);
  color: var(--brand-3);
  font-weight: 700;
  font-size: 1.05rem;
  line-height: 1;
  transition: transform 0.3s var(--ease), background 0.3s var(--ease),
    color 0.3s var(--ease);
}

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

#faq summary:hover {
  color: var(--brand);
}

#faq details p {
  margin: 0 0 14px;
  font-size: 0.92rem;
  animation: fadeUp 0.4s var(--ease) both;
}

/* ===== Contact / Address ===== */
#contact address {
  font-style: normal;
  background: var(--grad-soft);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px 22px;
  margin: 1em 0 1.4em;
}

#contact address p {
  margin: 0 0 0.6em;
  font-size: 0.93rem;
}

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

#contact address strong {
  color: var(--text);
}

#contact address a {
  font-weight: 600;
}

/* ===== Sitemap / Links ===== */
#sitemap ul,
#links ul {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
  gap: 10px;
}

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

#sitemap a,
#links a {
  display: block;
  padding: 10px 14px;
  background: var(--glass-bg);
  -webkit-backdrop-filter: var(--glass-blur);
  backdrop-filter: var(--glass-blur);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 0.88rem;
  color: var(--text-soft);
  text-align: center;
  transition: all 0.25s var(--ease);
}

#sitemap a:hover,
#links a:hover {
  background: var(--grad-brand);
  color: #fff;
  border-color: transparent;
  transform: translateY(-3px);
  box-shadow: 0 8px 20px rgba(242, 169, 0, 0.3);
}

/* ===== Footer ===== */
#site-footer {
  background: var(--grad-hero);
  color: rgba(255, 255, 255, 0.82);
  margin-top: 60px;
  padding: 48px 20px 24px;
  position: relative;
  overflow: hidden;
}

#site-footer::before {
  content: "";
  position: absolute;
  top: -30%;
  right: -10%;
  width: 480px;
  height: 480px;
  background: radial-gradient(circle, rgba(124, 92, 255, 0.3), transparent 62%);
  pointer-events: none;
}

.footer-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 28px 36px;
  position: relative;
  z-index: 1;
}

.footer-inner section {
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: var(--radius);
  padding: 18px 20px;
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
  transition: background 0.3s var(--ease), transform 0.3s var(--ease);
}

.footer-inner section:hover {
  background: rgba(255, 255, 255, 0.09);
  transform: translateY(-3px);
}

.footer-inner h2 {
  color: #fff;
  font-size: 0.98rem;
  margin: 0 0 0.6em;
  padding-left: 0;
}

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

.footer-inner p {
  color: rgba(255, 255, 255, 0.72);
  font-size: 0.85rem;
  margin: 0;
  line-height: 1.7;
}

.footer-meta {
  grid-column: 1 / -1;
  text-align: center;
  font-size: 0.8rem;
  color: rgba(255, 255, 255, 0.55);
  padding-top: 20px;
  border-top: 1px solid rgba(255, 255, 255, 0.12);
  margin: 0;
}

#back-to-top {
  position: fixed;
  right: 20px;
  bottom: 24px;
  z-index: 90;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  border: 1px solid rgba(255, 255, 255, 0.3);
  background: var(--grad-brand);
  color: #fff;
  font-size: 0.72rem;
  font-weight: 700;
  cursor: pointer;
  box-shadow: var(--shadow-lg);
  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);
  display: grid;
  place-items: center;
  line-height: 1.1;
  padding: 0;
}

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

#back-to-top:hover {
  filter: brightness(1.1);
  transform: translateY(-4px) scale(1.06);
}

/* ===== Scroll reveal utility ===== */
.reveal {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.7s var(--ease), transform 0.7s var(--ease);
}

.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* ===== Responsive ===== */
@media (max-width: 1080px) {
  #main-nav ul {
    gap: 0;
  }
  #main-nav a {
    padding: 6px 8px;
    font-size: 0.82rem;
  }
  #search-input {
    width: 120px;
  }
}

@media (max-width: 900px) {
  :root {
    --header-h: 64px;
  }
  .header-inner {
    flex-wrap: wrap;
    padding: 10px 16px;
  }
  #main-nav {
    order: 4;
    flex-basis: 100%;
    display: none;
    margin-top: 8px;
  }
  #main-nav.is-open {
    display: block;
    animation: fadeUp 0.35s var(--ease) both;
  }
  #main-nav ul {
    flex-direction: column;
    gap: 4px;
  }
  #main-nav a {
    display: block;
    padding: 10px 14px;
    border-radius: var(--radius-sm);
    background: var(--bg-soft);
    font-size: 0.9rem;
  }
  #menu-toggle {
    display: inline-block;
  }
  .header-tools {
    margin-left: auto;
  }
  #site-search {
    display: none;
  }
  .hero-stats {
    grid-template-columns: repeat(2, 1fr);
    margin-top: -24px;
  }
}

@media (max-width: 640px) {
  body {
    font-size: 15px;
  }
  main {
    padding: 0 14px 30px;
  }
  main > section {
    margin: 26px 0;
    padding: 22px 18px;
    border-radius: var(--radius);
  }
  #hero {
    margin-top: 14px !important;
  }
  .hero-slider {
    padding: 28px 20px 64px;
    border-radius: var(--radius);
  }
  .slider-controls {
    right: 16px;
    bottom: 16px;
  }
  .slider-controls button {
    width: 38px;
    height: 38px;
  }
  .hero-stats {
    gap: 10px;
    padding: 0 6px;
  }
  .hero-stats .stat {
    padding: 12px 8px;
  }
  h2 {
    padding-left: 14px;
    font-size: 1.25rem;
  }
  h2::before {
    width: 4px;
  }
  #faq details {
    padding: 2px 14px;
  }
  #faq summary {
    font-size: 0.9rem;
    padding: 12px 0;
    padding-right: 28px;
  }
  #sitemap ul,
  #links ul {
    grid-template-columns: repeat(2, 1fr);
    gap: 8px;
  }
  #anchor-nav {
    padding: 8px;
  }
  #anchor-nav a {
    padding: 5px 12px;
    font-size: 0.78rem;
  }
  .footer-inner {
    grid-template-columns: 1fr;
    gap: 16px;
  }
  #site-footer {
    padding: 36px 14px 20px;
  }
  #back-to-top {
    width: 44px;
    height: 44px;
    right: 14px;
    bottom: 16px;
  }
  blockquote {
    padding: 14px 16px;
  }
}

@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,
  .slider-controls,
  .header-tools {
    display: none !important;
  }
  body {
    background: #fff;
    color: #000;
  }
  main > section {
    box-shadow: none;
    border: 1px solid #ddd;
    break-inside: avoid;
  }
}