:root {
  --primary: #2b6cb0;
  --primary-dark: #1a4a7a;
  --primary-light: #4299e1;
  --accent: #38b2ac;
  --accent-2: #9f7aea;
  --bg: #f5f8fc;
  --bg-alt: #ffffff;
  --bg-elevated: rgba(255, 255, 255, 0.72);
  --bg-glass: rgba(255, 255, 255, 0.55);
  --text: #1a202c;
  --text-soft: #4a5568;
  --text-muted: #718096;
  --border: rgba(43, 108, 176, 0.14);
  --shadow-sm: 0 2px 8px rgba(26, 74, 122, 0.06);
  --shadow-md: 0 8px 24px rgba(26, 74, 122, 0.1);
  --shadow-lg: 0 16px 48px rgba(26, 74, 122, 0.14);
  --radius-sm: 10px;
  --radius: 16px;
  --radius-lg: 24px;
  --radius-xl: 32px;
  --max-width: 1200px;
  --header-h: 64px;
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
  --transition: 0.35s var(--ease);
}

[data-theme="dark"] {
  --primary: #63b3ed;
  --primary-dark: #4299e1;
  --primary-light: #90cdf4;
  --accent: #4fd1c5;
  --accent-2: #b794f4;
  --bg: #0d1117;
  --bg-alt: #161b22;
  --bg-elevated: rgba(22, 27, 34, 0.78);
  --bg-glass: rgba(22, 27, 34, 0.55);
  --text: #e6edf3;
  --text-soft: #b3c0cc;
  --text-muted: #8b98a5;
  --border: rgba(99, 179, 237, 0.18);
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 16px 48px rgba(0, 0, 0, 0.5);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --primary: #63b3ed;
    --primary-dark: #4299e1;
    --primary-light: #90cdf4;
    --accent: #4fd1c5;
    --accent-2: #b794f4;
    --bg: #0d1117;
    --bg-alt: #161b22;
    --bg-elevated: rgba(22, 27, 34, 0.78);
    --bg-glass: rgba(22, 27, 34, 0.55);
    --text: #e6edf3;
    --text-soft: #b3c0cc;
    --text-muted: #8b98a5;
    --border: rgba(99, 179, 237, 0.18);
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 16px 48px rgba(0, 0, 0, 0.5);
  }
}

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  scroll-padding-top: calc(var(--header-h) + 16px);
}

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(66, 153, 225, 0.1), transparent 42%),
    radial-gradient(circle at 88% 4%, rgba(159, 122, 234, 0.08), transparent 40%),
    radial-gradient(circle at 50% 100%, rgba(56, 178, 172, 0.06), transparent 50%);
  background-attachment: fixed;
  transition: background-color var(--transition), color var(--transition);
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

img,
svg {
  max-width: 100%;
  height: auto;
  vertical-align: middle;
}

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

a:hover,
a:focus-visible {
  color: var(--primary-dark);
  text-decoration: underline;
  text-underline-offset: 3px;
}

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

h1, h2, h3, h4, h5, h6 {
  margin: 0 0 0.6em;
  line-height: 1.3;
  font-weight: 700;
  color: var(--text);
  letter-spacing: -0.01em;
}

h1 {
  font-size: clamp(1.75rem, 1.2rem + 2.4vw, 2.75rem);
  background: linear-gradient(120deg, var(--primary-dark), var(--primary), var(--accent));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: var(--primary);
}

h2 {
  font-size: clamp(1.4rem, 1.1rem + 1.4vw, 2rem);
  position: relative;
  padding-bottom: 0.5em;
}

h2::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 56px;
  height: 4px;
  border-radius: 4px;
  background: linear-gradient(90deg, var(--primary), var(--accent));
}

h3 {
  font-size: clamp(1.1rem, 1rem + 0.6vw, 1.35rem);
  color: var(--primary-dark);
}

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

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

li {
  margin-bottom: 0.45em;
}

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

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

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

/* ============ HEADER ============ */
#site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--bg-glass);
  -webkit-backdrop-filter: blur(18px) saturate(160%);
  backdrop-filter: blur(18px) saturate(160%);
  border-bottom: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
  transition: background-color var(--transition), box-shadow var(--transition);
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 6px clamp(16px, 4vw, 40px);
  font-size: 0.8rem;
  color: #fff;
  background: linear-gradient(90deg, var(--primary-dark), var(--primary), var(--accent-2));
  flex-wrap: wrap;
}

.topbar p {
  margin: 0;
  color: rgba(255, 255, 255, 0.92);
  font-size: 0.8rem;
}

.topbar nav {
  display: flex;
  gap: 18px;
}

.topbar nav a {
  color: rgba(255, 255, 255, 0.92);
  font-size: 0.8rem;
  position: relative;
}

.topbar nav a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -2px;
  width: 0;
  height: 2px;
  background: #fff;
  border-radius: 2px;
  transition: width var(--transition);
}

.topbar nav a:hover::after,
.topbar nav a:focus-visible::after {
  width: 100%;
}

.topbar nav a:hover {
  color: #fff;
  text-decoration: none;
}

.brandbar {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 10px clamp(16px, 4vw, 40px);
  flex-wrap: wrap;
}

.logo {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  font-size: 1.05rem;
  color: var(--text);
  text-decoration: none;
  flex-shrink: 0;
}

.logo:hover {
  text-decoration: none;
  opacity: 0.9;
}

.logo svg {
  border-radius: 12px;
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition);
}

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

.logo span {
  max-width: 260px;
  line-height: 1.25;
  background: linear-gradient(120deg, var(--primary-dark), var(--accent-2));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.brandbar form[role="search"] {
  display: flex;
  align-items: center;
  gap: 8px;
  flex: 1 1 260px;
  max-width: 460px;
  position: relative;
}

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

.brandbar input[type="search"] {
  flex: 1;
  min-width: 0;
  padding: 10px 16px;
  font-size: 0.9rem;
  color: var(--text);
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: 999px;
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  transition: border-color var(--transition), box-shadow var(--transition),
    background-color var(--transition);
}

.brandbar input[type="search"]::placeholder {
  color: var(--text-muted);
}

.brandbar input[type="search"]:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 4px rgba(66, 153, 225, 0.18);
}

.brandbar form[role="search"] button {
  padding: 10px 20px;
  font-size: 0.9rem;
  font-weight: 600;
  color: #fff;
  background: linear-gradient(135deg, var(--primary), var(--primary-light));
  border: none;
  border-radius: 999px;
  cursor: pointer;
  white-space: nowrap;
  box-shadow: 0 4px 14px rgba(43, 108, 176, 0.28);
  transition: transform var(--transition), box-shadow var(--transition),
    filter var(--transition);
}

.brandbar form[role="search"] button:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 22px rgba(43, 108, 176, 0.36);
  filter: brightness(1.06);
}

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

#theme-toggle,
#menu-toggle {
  padding: 9px 18px;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--primary-dark);
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: 999px;
  cursor: pointer;
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  transition: transform var(--transition), box-shadow var(--transition),
    background-color var(--transition), color var(--transition);
  white-space: nowrap;
}

#theme-toggle:hover,
#menu-toggle:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
  background: var(--primary);
  color: #fff;
  border-color: transparent;
}

#menu-toggle {
  display: none;
}

#main-nav {
  border-top: 1px solid var(--border);
  padding: 0 clamp(16px, 4vw, 40px);
  overflow-x: auto;
  scrollbar-width: none;
}

#main-nav::-webkit-scrollbar {
  display: none;
}

#main-nav ul {
  display: flex;
  gap: 4px;
  margin: 0;
  padding: 6px 0;
  list-style: none;
  padding-left: 0;
}

#main-nav li {
  margin: 0;
}

#main-nav a {
  display: block;
  padding: 8px 14px;
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--text-soft);
  border-radius: 999px;
  white-space: nowrap;
  transition: background-color var(--transition), color var(--transition),
    transform var(--transition);
}

#main-nav a:hover,
#main-nav a:focus-visible {
  color: #fff;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  text-decoration: none;
  transform: translateY(-1px);
}

/* ============ MAIN LAYOUT ============ */
main {
  display: block;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 24px clamp(16px, 4vw, 40px) 64px;
}

main > section {
  margin-bottom: 56px;
  padding: clamp(20px, 3.5vw, 40px);
  background: var(--bg-elevated);
  -webkit-backdrop-filter: blur(16px) saturate(150%);
  backdrop-filter: blur(16px) saturate(150%);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  transition: box-shadow var(--transition), transform var(--transition),
    border-color var(--transition);
}

main > section:hover {
  box-shadow: var(--shadow-md);
  border-color: rgba(66, 153, 225, 0.28);
}

/* Scroll reveal animation */
main > section,
main > section > article,
main > section > details {
  animation: fadeUp 0.7s var(--ease) both;
}

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

@supports (animation-timeline: view()) {
  main > section {
    animation: fadeUp linear both;
    animation-timeline: view();
    animation-range: entry 0% cover 28%;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* ============ BREADCRUMB ============ */
#breadcrumb {
  margin-bottom: 20px;
  padding: 10px 16px;
  background: var(--bg-glass);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
  border: 1px solid var(--border);
  border-radius: 999px;
  font-size: 0.82rem;
}

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

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

#breadcrumb li + li::before {
  content: "›";
  color: var(--primary);
  font-weight: 700;
}

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

#breadcrumb a:hover {
  color: var(--primary);
  text-decoration: none;
}

#breadcrumb [aria-current="page"] {
  color: var(--primary);
  font-weight: 600;
}

/* ============ HERO ============ */
#hero {
  position: relative;
  overflow: hidden;
  background:
    linear-gradient(135deg, rgba(43, 108, 176, 0.92), rgba(56, 178, 172, 0.82) 55%, rgba(159, 122, 234, 0.85)),
    var(--bg-alt);
  background-size: 200% 200%;
  animation: gradientShift 16s ease infinite, fadeUp 0.7s var(--ease) both;
  color: #fff;
  border: none;
  box-shadow: var(--shadow-lg);
}

#hero::before,
#hero::after {
  content: "";
  position: absolute;
  border-radius: 50%;
  filter: blur(60px);
  opacity: 0.5;
  pointer-events: none;
}

#hero::before {
  width: 340px;
  height: 340px;
  top: -120px;
  right: -80px;
  background: rgba(255, 255, 255, 0.35);
  animation: floatBlob 12s ease-in-out infinite;
}

#hero::after {
  width: 260px;
  height: 260px;
  bottom: -100px;
  left: -60px;
  background: rgba(66, 153, 225, 0.55);
  animation: floatBlob 14s ease-in-out infinite reverse;
}

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

@keyframes floatBlob {
  0%, 100% { transform: translate(0, 0) scale(1); }
  50% { transform: translate(30px, -24px) scale(1.12); }
}

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

#hero h1 {
  -webkit-text-fill-color: #fff;
  color: #fff;
  background: none;
  text-shadow: 0 2px 18px rgba(0, 0, 0, 0.18);
}

#hero p {
  color: rgba(255, 255, 255, 0.92);
  max-width: 820px;
  text-shadow: 0 1px 8px rgba(0, 0, 0, 0.12);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin: 8px 0 28px;
}

.btn-primary,
.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 13px 30px;
  font-size: 0.95rem;
  font-weight: 700;
  border-radius: 999px;
  text-decoration: none;
  transition: transform var(--transition), box-shadow var(--transition),
    background-color var(--transition), color var(--transition);
  will-change: transform;
}

.btn-primary {
  color: var(--primary-dark);
  background: #fff;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.18);
}

.btn-primary:hover {
  color: var(--primary-dark);
  text-decoration: none;
  transform: translateY(-3px) scale(1.02);
  box-shadow: 0 14px 34px rgba(0, 0, 0, 0.26);
}

.btn-secondary {
  color: #fff;
  background: rgba(255, 255, 255, 0.14);
  border: 1.5px solid rgba(255, 255, 255, 0.6);
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
}

.btn-secondary:hover {
  color: #fff;
  text-decoration: none;
  background: rgba(255, 255, 255, 0.26);
  transform: translateY(-3px) scale(1.02);
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.2);
}

/* Slider */
.hero-slider {
  position: relative;
  margin: 0 0 28px;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.24);
  background: rgba(0, 0, 0, 0.14);
}

.hero-slider .slide {
  display: none;
  margin: 0;
  position: relative;
}

.hero-slider .slide.active {
  display: block;
  animation: slideIn 0.6s var(--ease);
}

@keyframes slideIn {
  from { opacity: 0; transform: scale(1.03); }
  to { opacity: 1; transform: scale(1); }
}

.hero-slider .slide svg {
  display: block;
  width: 100%;
  height: auto;
}

.hero-slider figcaption {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  padding: 40px 24px 18px;
  font-size: clamp(0.9rem, 0.8rem + 0.5vw, 1.15rem);
  font-weight: 600;
  color: #fff;
  background: linear-gradient(to top, rgba(0, 0, 0, 0.62), transparent);
  letter-spacing: 0.02em;
}

.slider-prev,
.slider-next {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  z-index: 2;
  padding: 10px 16px;
  font-size: 0.8rem;
  font-weight: 600;
  color: #fff;
  background: rgba(0, 0, 0, 0.32);
  border: 1px solid rgba(255, 255, 255, 0.3);
  border-radius: 999px;
  cursor: pointer;
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
  transition: background-color var(--transition), transform var(--transition);
}

.slider-prev { left: 14px; }
.slider-next { right: 14px; }

.slider-prev:hover,
.slider-next:hover {
  background: rgba(0, 0, 0, 0.6);
  transform: translateY(-50%) scale(1.06);
}

/* Stats */
.stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.stats li {
  margin: 0;
  padding: 18px 14px;
  text-align: center;
  background: rgba(255, 255, 255, 0.16);
  border: 1px solid rgba(255, 255, 255, 0.28);
  border-radius: var(--radius);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
  transition: transform var(--transition), background-color var(--transition);
}

.stats li:hover {
  transform: translateY(-5px);
  background: rgba(255, 255, 255, 0.26);
}

.stats strong {
  display: block;
  font-size: clamp(1.4rem, 1.1rem + 1.2vw, 2.1rem);
  font-weight: 800;
  color: #fff;
  line-height: 1.2;
  letter-spacing: -0.02em;
}

.stats span {
  display: block;
  margin-top: 4px;
  font-size: 0.8rem;
  color: rgba(255, 255, 255, 0.88);
}

/* ============ TABLES ============ */
table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
  margin: 0 0 1.4em;
  font-size: 0.92rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--bg-alt);
}

caption {
  caption-side: top;
  padding: 10px 4px;
  font-weight: 700;
  font-size: 0.9rem;
  color: var(--text-muted);
  text-align: left;
}

th, td {
  padding: 12px 16px;
  text-align: left;
  border-bottom: 1px solid var(--border);
  vertical-align: top;
}

th {
  font-weight: 700;
  color: var(--text);
  background: rgba(66, 153, 225, 0.08);
  white-space: nowrap;
}

tbody tr:last-child th,
tbody tr:last-child td {
  border-bottom: none;
}

tbody tr {
  transition: background-color var(--transition);
}

tbody tr:hover {
  background: rgba(66, 153, 225, 0.06);
}

td {
  color: var(--text-soft);
}

/* ============ ARTICLES / NEWS / CARDS ============ */
#news article,
#articles > article {
  position: relative;
  padding: 20px 22px;
  margin-bottom: 16px;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition), box-shadow var(--transition),
    border-color var(--transition);
}

#news article::before,
#articles > article::before {
  content: "";
  position: absolute;
  left: 0;
  top: 16px;
  bottom: 16px;
  width: 4px;
  border-radius: 4px;
  background: linear-gradient(180deg, var(--primary), var(--accent));
  opacity: 0;
  transition: opacity var(--transition);
}

#news article:hover,
#articles > article:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: rgba(66, 153, 225, 0.3);
}

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

#news h3,
#articles > article h3 {
  margin-bottom: 6px;
}

#news h3 a,
#articles > article h3 a {
  color: inherit;
}

#articles > article > a {
  display: inline-block;
  margin-top: 6px;
  font-weight: 600;
  font-size: 0.9rem;
  padding: 6px 16px;
  border-radius: 999px;
  background: rgba(66, 153, 225, 0.1);
  transition: background-color var(--transition), color var(--transition),
    transform var(--transition);
}

#articles > article > a:hover {
  background: var(--primary);
  color: #fff;
  text-decoration: none;
  transform: translateX(4px);
}

/* Inline article sections */
#articles section[id^="article-"] {
  margin-top: 20px;
  padding: 22px 24px;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  transition: box-shadow var(--transition), transform var(--transition);
}

#articles section[id^="article-"]:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

#articles section[id^="article-"] p:last-child {
  margin-bottom: 0;
}

/* ============ BLOCKQUOTE ============ */
blockquote {
  position: relative;
  margin: 0 0 16px;
  padding: 20px 24px 20px 56px;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-left: 4px solid var(--accent);
  border-radius: 0 var(--radius) var(--radius) 0;
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition), box-shadow var(--transition);
}

blockquote::before {
  content: "\201C";
  position: absolute;
  left: 16px;
  top: 4px;
  font-size: 3rem;
  line-height: 1;
  font-family: Georgia, serif;
  color: var(--primary-light);
  opacity: 0.6;
}

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

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

/* ============ FAQ ============ */
#faq details {
  margin-bottom: 12px;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  overflow: hidden;
  transition: box-shadow var(--transition), border-color var(--transition);
}

#faq details[open] {
  box-shadow: var(--shadow-md);
  border-color: rgba(66, 153, 225, 0.32);
}

#faq summary {
  position: relative;
  padding: 16px 52px 16px 20px;
  font-weight: 600;
  font-size: 0.98rem;
  color: var(--text);
  cursor: pointer;
  list-style: none;
  transition: background-color var(--transition), color var(--transition);
}

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

#faq summary::after {
  content: "+";
  position: absolute;
  right: 18px;
  top: 50%;
  transform: translateY(-50%);
  width: 26px;
  height: 26px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.15rem;
  font-weight: 700;
  color: #fff;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  border-radius: 50%;
  transition: transform var(--transition);
}

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

#faq summary:hover {
  background: rgba(66, 153, 225, 0.08);
  color: var(--primary-dark);
}

#faq details[open] summary {
  color: var(--primary-dark);
  border-bottom: 1px solid var(--border);
}

#faq details p {
  margin: 0;
  padding: 16px 20px 20px;
  font-size: 0.94rem;
  color: var(--text-soft);
  animation: fadeIn 0.4s var(--ease);
}

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

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

#howto ol > li {
  position: relative;
  padding: 12px 16px 12px 56px;
  margin-bottom: 10px;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  counter-increment: step;
  transition: transform var(--transition), box-shadow var(--transition);
}

#howto ol > li::before {
  content: counter(step);
  position: absolute;
  left: 14px;
  top: 50%;
  transform: translateY(-50%);
  width: 30px;
  height: 30px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.85rem;
  font-weight: 800;
  color: #fff;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  border-radius: 50%;
  box-shadow: 0 3px 10px rgba(43, 108, 176, 0.3);
}

#howto ol > li:hover {
  transform: translateX(5px);
  box-shadow: var(--shadow-sm);
}

#brand ol > li,
#about ul > li,
#products ul > li,
#solutions ul > li,
#industry ul > li,
#knowledge ul > li,
#howto ul > li,
#notice ul > li,
#sitemap ul > li,
#links ul > li {
  padding: 8px 14px;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  margin-bottom: 8px;
  transition: transform var(--transition), border-color var(--transition),
    box-shadow var(--transition);
}

#brand ol > li:hover,
#about ul > li:hover,
#products ul > li:hover,
#solutions ul > li:hover,
#industry ul > li:hover,
#knowledge ul > li:hover,
#howto ul > li:hover,
#notice ul > li:hover,
#sitemap ul > li:hover,
#links ul > li:hover {
  transform: translateX(4px);
  border-color: rgba(66, 153, 225, 0.35);
  box-shadow: var(--shadow-sm);
}

/* ============ CONTACT ============ */
#contact address {
  font-style: normal;
  padding: 20px 22px;
  background: linear-gradient(135deg, rgba(66, 153, 225, 0.08), rgba(56, 178, 172, 0.08));
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

#contact address p {
  margin: 0 0 8px;
}

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

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

#contact address a:hover {
  text-decoration: none;
  border-bottom-style: solid;
}

/* ============ SITEMAP / LINKS ============ */
#sitemap ul,
#links ul {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  gap: 10px;
  list-style: none;
  padding-left: 0;
}

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

#sitemap a,
#links a {
  display: block;
  font-size: 0.9rem;
}

/* ============ FOOTER ============ */
#site-footer {
  margin-top: 40px;
  padding: clamp(32px, 5vw, 56px) clamp(16px, 4vw, 40px) 32px;
  background: linear-gradient(160deg, var(--primary-dark), #0f2a44 55%, #0a1e33);
  color: rgba(255, 255, 255, 0.82);
  position: relative;
  overflow: hidden;
}

#site-footer::before {
  content: "";
  position: absolute;
  top: -120px;
  right: -80px;
  width: 320px;
  height: 320px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(66, 153, 225, 0.35), transparent 70%);
  filter: blur(40px);
  pointer-events: none;
}

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

.footer-meta {
  display: grid;
  gap: 4px;
  padding-bottom: 22px;
  margin-bottom: 22px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.14);
}

.footer-meta p {
  margin: 0;
  font-size: 0.82rem;
  color: rgba(255, 255, 255, 0.7);
}

.footer-meta time {
  color: rgba(255, 255, 255, 0.7);
}

#site-footer nav ul {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 24px;
  list-style: none;
  padding: 0;
  margin: 0 0 26px;
}

#site-footer nav li {
  margin: 0;
}

#site-footer nav a {
  color: rgba(255, 255, 255, 0.82);
  font-size: 0.88rem;
  position: relative;
  padding-bottom: 2px;
}

#site-footer nav a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 0;
  height: 2px;
  background: var(--accent);
  border-radius: 2px;
  transition: width var(--transition);
}

#site-footer nav a:hover {
  color: #fff;
  text-decoration: none;
}

#site-footer nav a:hover::after {
  width: 100%;
}

#site-footer section {
  margin-bottom: 20px;
  padding: 18px 20px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: var(--radius);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  transition: background-color var(--transition), transform var(--transition);
}

#site-footer section:hover {
  background: rgba(255, 255, 255, 0.09);
  transform: translateY(-2px);
}

#site-footer h2 {
  font-size: 1rem;
  color: #fff;
  margin-bottom: 8px;
  padding-bottom: 0;
}

#site-footer h2::after {
  display: none;
}

#site-footer section p {
  margin: 0;
  font-size: 0.84rem;
  color: rgba(255, 255, 255, 0.72);
  line-height: 1.7;
}

/* ============ BACK TO TOP ============ */
#back-to-top {
  position: fixed;
  right: 20px;
  bottom: 24px;
  z-index: 900;
  padding: 12px 18px;
  font-size: 0.82rem;
  font-weight: 700;
  color: #fff;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  border: none;
  border-radius: 999px;
  cursor: pointer;
  box-shadow: 0 10px 28px rgba(43, 108, 176, 0.4);
  opacity: 0;
  visibility: hidden;
  transform: translateY(16px);
  transition: opacity var(--transition), visibility var(--transition),
    transform var(--transition), box-shadow var(--transition);
}

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

#back-to-top:hover {
  transform: translateY(-4px) scale(1.05);
  box-shadow: 0 16px 36px rgba(43, 108, 176, 0.5);
}

/* ============ RESPONSIVE ============ */
@media (max-width: 960px) {
  .stats {
    grid-template-columns: repeat(2, 1fr);
  }

  .brandbar form[role="search"] {
    order: 3;
    flex-basis: 100%;
    max-width: none;
  }
}

@media (max-width: 768px) {
  :root {
    --header-h: 56px;
  }

  .topbar {
    justify-content: center;
    text-align: center;
    gap: 8px;
  }

  .topbar p {
    font-size: 0.74rem;
  }

  .topbar nav {
    gap: 14px;
  }

  .topbar nav a {
    font-size: 0.74rem;
  }

  .brandbar {
    gap: 10px;
    padding-top: 8px;
    padding-bottom: 8px;
  }

  .logo span {
    font-size: 0.92rem;
    max-width: 180px;
  }

  #theme-toggle,
  #menu-toggle {
    padding: 8px 14px;
    font-size: 0.8rem;
  }

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

  #main-nav {
    display: none;
    border-top: 1px solid var(--border);
    padding-bottom: 10px;
  }

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

  #main-nav ul {
    flex-direction: column;
    gap: 2px;
    padding: 8px 0;
  }

  #main-nav a {
    padding: 11px 16px;
    border-radius: var(--radius-sm);
  }

  main {
    padding-top: 16px;
    padding-bottom: 48px;
  }

  main > section {
    margin-bottom: 32px;
    border-radius: var(--radius);
  }

  .hero-slider figcaption {
    padding: 28px 16px 12px;
  }

  .slider-prev,
  .slider-next {
    padding: 7px 11px;
    font-size: 0.72rem;
  }

  .slider-prev { left: 8px; }
  .slider-next { right: 8px; }

  .stats {
    grid-template-columns: repeat(2, 1fr);
    gap: 10px;
  }

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

  blockquote {
    padding: 16px 16px 16px 44px;
  }

  #howto ol > li {
    padding-left: 50px;
  }

  .btn-primary,
  .btn-secondary {
    padding: 12px 22px;
    font-size: 0.9rem;
    flex: 1 1 auto;
  }

  .hero-actions {
    gap: 10px;
  }

  #back-to-top {
    right: 14px;
    bottom: 16px;
    padding: 10px 14px;
    font-size: 0.76rem;
  }

  table {
    display: block;
    overflow-x: auto;
    white-space: nowrap;
    -webkit-overflow-scrolling: touch;
  }
}

@media (max-width: 480px) {
  body {
    font-size: 15px;
  }

  .brandbar form[role="search"] button {
    padding: 10px 16px;
  }

  .logo svg {
    width: 40px;
    height: 40px;
  }

  .logo span {
    font-size: 0.84rem;
    max-width: 150px;
  }

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

  .stats strong {
    font-size: 1.3rem;
  }
}

/* ============ PRINT ============ */
@media print {
  #site-header,
  #back-to-top,
  .hero-slider,
  .hero-actions,
  #sitemap,
  #links {
    display: none !important;
  }

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

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

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