:root {
  --bg-body: #f8fafc;
  --bg-surface: #ffffff;
  --bg-elevated: #f1f5f9;
  --bg-nav: rgba(255, 255, 255, 0.82);
  --bg-footer: #1e293b;
  --bg-card: #ffffff;
  --bg-banner: #0f172a;
  --bg-faq: #ffffff;
  --bg-search: #ffffff;
  --bg-tag: #e2e8f0;

  --text-primary: #0f172a;
  --text-secondary: #1e293b;
  --text-body: #1e293b;
  --text-muted: #475569;
  --text-light: #64748b;
  --text-on-dark: #f1f5f9;
  --text-on-dark-muted: #cbd5e1;
  --text-link: #1e4b8a;
  --text-link-hover: #0f2b52;
  --text-btn: #ffffff;
  --text-nav: #0f172a;
  --text-footer: #e2e8f0;
  --text-footer-heading: #ffffff;
  --text-faq-q: #0f172a;
  --text-faq-a: #1e293b;
  --text-table-head: #0f172a;
  --text-placeholder: #64748b;
  --text-error: #b91c1c;

  --border-light: #e2e8f0;
  --border-medium: #cbd5e1;
  --border-dark: #334155;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.07);
  --shadow-lg: 0 10px 24px -6px rgba(15, 23, 42, 0.16);
  --shadow-glow: 0 8px 32px -8px rgba(37, 99, 235, 0.35);
  --brand: #2563eb;
  --brand-dark: #1d4ed8;
  --brand-deep: #1e3a8a;
  --brand-light: #dbeafe;
  --brand-cyan: #06b6d4;
  --brand-violet: #7c3aed;
  --gradient-banner: linear-gradient(135deg, #0f172a 0%, #1e3a8a 45%, #2563eb 100%);
  --gradient-brand: linear-gradient(135deg, #2563eb 0%, #7c3aed 100%);
  --gradient-accent: linear-gradient(135deg, #06b6d4 0%, #2563eb 100%);
  --glass-bg: rgba(255, 255, 255, 0.65);
  --glass-border: rgba(255, 255, 255, 0.5);
  --glass-blur: saturate(180%) blur(14px);
}

body.dark-mode {
  --bg-body: #0b1120;
  --bg-surface: #111827;
  --bg-elevated: #1e293b;
  --bg-nav: rgba(15, 23, 42, 0.82);
  --bg-footer: #020617;
  --bg-card: #111827;
  --bg-banner: #020617;
  --bg-faq: #111827;
  --bg-search: #1e293b;
  --bg-tag: #1e293b;

  --text-primary: #f8fafc;
  --text-secondary: #e2e8f0;
  --text-body: #e2e8f0;
  --text-muted: #cbd5e1;
  --text-light: #94a3b8;
  --text-on-dark: #f1f5f9;
  --text-on-dark-muted: #cbd5e1;
  --text-link: #93c5fd;
  --text-link-hover: #bfdbfe;
  --text-btn: #0f172a;
  --text-nav: #f1f5f9;
  --text-footer: #e2e8f0;
  --text-footer-heading: #ffffff;
  --text-faq-q: #f1f5f9;
  --text-faq-a: #e2e8f0;
  --text-table-head: #f1f5f9;
  --text-placeholder: #94a3b8;
  --text-error: #fca5a5;

  --border-light: #1e293b;
  --border-medium: #334155;
  --border-dark: #475569;
  --brand: #3b82f6;
  --brand-dark: #60a5fa;
  --brand-deep: #93c5fd;
  --brand-light: #1e3a8a;
  --gradient-banner: linear-gradient(135deg, #020617 0%, #0f172a 45%, #1e3a8a 100%);
  --gradient-brand: linear-gradient(135deg, #3b82f6 0%, #7c3aed 100%);
  --gradient-accent: linear-gradient(135deg, #06b6d4 0%, #3b82f6 100%);
  --glass-bg: rgba(17, 24, 39, 0.6);
  --glass-border: rgba(148, 163, 184, 0.18);
  --shadow-lg: 0 10px 24px -6px rgba(0, 0, 0, 0.5);
  --shadow-glow: 0 8px 32px -8px rgba(59, 130, 246, 0.4);
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  background-color: var(--bg-body);
  color: var(--text-body);
  line-height: 1.7;
  transition: background-color 0.3s ease, color 0.3s ease;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
  color: var(--text-primary);
  font-weight: 700;
  line-height: 1.3;
  margin-bottom: 0.5em;
  transition: color 0.3s ease;
}

h1 {
  font-size: 2.4rem;
  letter-spacing: -0.02em;
  color: var(--text-primary);
}

h2 {
  font-size: 1.9rem;
  margin-top: 2rem;
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 3px solid transparent;
  border-image: var(--gradient-brand) 1;
  display: inline-block;
  color: var(--text-primary);
}

h3 {
  font-size: 1.45rem;
  margin-top: 1.5rem;
  margin-bottom: 0.75rem;
  color: var(--text-primary);
}

h4 {
  font-size: 1.2rem;
  margin-top: 1.25rem;
  margin-bottom: 0.5rem;
  color: var(--text-secondary);
}

p {
  margin-bottom: 1rem;
  color: var(--text-body);
  transition: color 0.3s ease;
}

a {
  color: var(--text-link);
  text-decoration: none;
  transition: color 0.2s ease, text-decoration 0.2s ease;
}

a:hover {
  color: var(--text-link-hover);
  text-decoration: underline;
}

a:focus-visible {
  outline: 3px solid var(--brand);
  outline-offset: 2px;
  border-radius: 3px;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

.navbar {
  position: sticky;
  top: 0;
  z-index: 1000;
  background-color: var(--bg-nav);
  -webkit-backdrop-filter: var(--glass-blur);
  backdrop-filter: var(--glass-blur);
  border-bottom: 1px solid var(--glass-border);
  box-shadow: var(--shadow-sm);
  transition: background-color 0.3s ease, border-color 0.3s ease;
}

.navbar .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--text-primary);
  letter-spacing: -0.02em;
}

.nav-logo svg {
  width: 36px;
  height: 36px;
  flex-shrink: 0;
  border-radius: 10px;
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.nav-logo:hover svg {
  transform: rotate(-6deg) scale(1.06);
  box-shadow: var(--shadow-glow);
}

.nav-logo span {
  background: var(--gradient-brand);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 28px;
  list-style: none;
}

.nav-menu a {
  color: var(--text-nav);
  font-weight: 500;
  font-size: 0.95rem;
  padding: 6px 0;
  position: relative;
  transition: color 0.2s ease;
}

.nav-menu a:hover {
  color: var(--brand-deep);
  text-decoration: none;
}

.nav-menu a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--gradient-brand);
  border-radius: 2px;
  transition: width 0.25s ease;
}

.nav-menu a:hover::after {
  width: 100%;
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 16px;
}

.search-box {
  display: flex;
  align-items: center;
  background-color: var(--glass-bg);
  -webkit-backdrop-filter: var(--glass-blur);
  backdrop-filter: var(--glass-blur);
  border: 1px solid var(--border-medium);
  border-radius: 40px;
  padding: 4px 4px 4px 16px;
  transition: border-color 0.2s ease, background-color 0.3s ease, box-shadow 0.25s ease;
}

.search-box:focus-within {
  border-color: var(--brand);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15), var(--shadow-glow);
}

.search-box input {
  border: none;
  background: transparent;
  color: var(--text-body);
  font-size: 0.9rem;
  outline: none;
  width: 160px;
  padding: 6px 0;
}

.search-box input::placeholder {
  color: var(--text-placeholder);
  opacity: 1;
}

.search-box button {
  background: var(--gradient-brand);
  color: var(--text-btn);
  border: none;
  border-radius: 40px;
  padding: 7px 16px;
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  transition: filter 0.2s ease, transform 0.2s ease, box-shadow 0.2s ease;
}

.search-box button:hover {
  filter: brightness(1.08);
  transform: translateY(-1px);
  box-shadow: var(--shadow-glow);
}

.theme-toggle {
  background: var(--glass-bg);
  -webkit-backdrop-filter: var(--glass-blur);
  backdrop-filter: var(--glass-blur);
  border: 1px solid var(--border-medium);
  border-radius: 50%;
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  color: var(--text-primary);
  transition: background-color 0.2s ease, border-color 0.2s ease, color 0.3s ease, transform 0.3s ease;
  flex-shrink: 0;
}

.theme-toggle:hover {
  background-color: var(--bg-elevated);
  transform: rotate(20deg);
}

.theme-toggle svg {
  width: 20px;
  height: 20px;
  fill: currentColor;
}

.mobile-menu-btn {
  display: none;
  background: var(--glass-bg);
  -webkit-backdrop-filter: var(--glass-blur);
  backdrop-filter: var(--glass-blur);
  border: 1px solid var(--border-medium);
  border-radius: 8px;
  width: 42px;
  height: 42px;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  color: var(--text-primary);
  flex-shrink: 0;
}

.mobile-menu-btn svg {
  width: 24px;
  height: 24px;
  fill: currentColor;
}

.banner {
  position: relative;
  background: var(--gradient-banner);
  color: var(--text-on-dark);
  overflow: hidden;
  min-height: 460px;
  display: flex;
  align-items: center;
}

.banner::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 18% 20%, rgba(37, 99, 235, 0.45), transparent 42%),
    radial-gradient(circle at 82% 78%, rgba(124, 58, 237, 0.38), transparent 46%),
    radial-gradient(circle at 60% 10%, rgba(6, 182, 212, 0.28), transparent 40%);
  z-index: 1;
  pointer-events: none;
}

.banner::after {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.04) 1px, transparent 1px);
  background-size: 48px 48px;
  z-index: 1;
  pointer-events: none;
  mask-image: radial-gradient(ellipse at center, #000 20%, transparent 78%);
  -webkit-mask-image: radial-gradient(ellipse at center, #000 20%, transparent 78%);
}

.banner-slide {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  opacity: 0;
  transition: opacity 0.8s ease;
  pointer-events: none;
}

.banner-slide.active {
  opacity: 1;
  pointer-events: auto;
  position: relative;
}

.banner-content {
  position: relative;
  z-index: 2;
  max-width: 650px;
  padding: 60px 0;
}

.banner-content h1 {
  color: #ffffff;
  font-size: 2.8rem;
  margin-bottom: 1rem;
  text-shadow: 0 2px 12px rgba(0, 0, 0, 0.5);
  animation: bannerFadeUp 0.7s ease both;
}

.banner-content p {
  color: #e2e8f0;
  font-size: 1.15rem;
  margin-bottom: 1.5rem;
  text-shadow: 0 1px 6px rgba(0, 0, 0, 0.4);
  animation: bannerFadeUp 0.7s 0.1s ease both;
}

.banner-tag {
  display: inline-block;
  background: rgba(255, 255, 255, 0.14);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.28);
  color: #ffffff;
  font-size: 0.8rem;
  font-weight: 600;
  padding: 4px 14px;
  border-radius: 20px;
  margin-bottom: 1rem;
  letter-spacing: 0.5px;
  animation: bannerFadeUp 0.7s ease both;
}

.banner-btn {
  display: inline-block;
  background: var(--gradient-brand);
  color: #ffffff;
  font-weight: 600;
  padding: 12px 32px;
  border-radius: 40px;
  font-size: 1rem;
  transition: filter 0.2s ease, transform 0.2s ease, box-shadow 0.25s ease;
  text-decoration: none;
  border: none;
  cursor: pointer;
  box-shadow: 0 8px 24px -8px rgba(37, 99, 235, 0.7);
  animation: bannerFadeUp 0.7s 0.2s ease both;
}

.banner-btn:hover {
  filter: brightness(1.1);
  color: #ffffff;
  text-decoration: none;
  transform: translateY(-3px);
  box-shadow: 0 14px 32px -8px rgba(37, 99, 235, 0.85);
}

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

.banner-dots {
  position: absolute;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  gap: 10px;
  z-index: 10;
}

.banner-dots button {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  border: 2px solid #ffffff;
  background: transparent;
  cursor: pointer;
  padding: 0;
  transition: background-color 0.3s ease, transform 0.3s ease, width 0.3s ease;
}

.banner-dots button.active {
  background-color: #ffffff;
  width: 30px;
  border-radius: 8px;
}

.stats-section {
  background-color: var(--bg-surface);
  padding: 48px 0;
  border-bottom: 1px solid var(--border-light);
  position: relative;
  overflow: hidden;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  text-align: center;
}

.stat-item {
  padding: 16px 8px;
  border-radius: 16px;
  transition: transform 0.3s ease, background-color 0.3s ease;
}

.stat-item:hover {
  transform: translateY(-4px);
  background-color: var(--bg-elevated);
}

.stat-item .stat-number {
  font-size: 2.6rem;
  font-weight: 800;
  background: var(--gradient-brand);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
  line-height: 1.2;
}

.stat-item .stat-label {
  font-size: 0.95rem;
  color: var(--text-muted);
  margin-top: 4px;
  font-weight: 500;
}

section {
  padding: 60px 0;
}

.section-alt {
  background-color: var(--bg-elevated);
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 24px;
  margin-top: 24px;
}

.card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: 18px;
  padding: 28px 24px;
  transition: box-shadow 0.3s ease, border-color 0.3s ease, transform 0.3s ease, background-color 0.3s ease;
  box-shadow: var(--shadow-sm);
  position: relative;
  overflow: hidden;
}

.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--gradient-brand);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.35s ease;
}

.card:hover {
  box-shadow: var(--shadow-lg);
  border-color: var(--brand);
  transform: translateY(-6px);
}

.card:hover::before {
  transform: scaleX(1);
}

.card h3 {
  font-size: 1.25rem;
  margin-top: 0;
  margin-bottom: 0.6rem;
  color: var(--text-primary);
}

.card p {
  color: var(--text-body);
  font-size: 0.95rem;
  margin-bottom: 0.5rem;
}

.card .card-meta {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-top: 8px;
}

.card .read-more {
  display: inline-block;
  margin-top: 12px;
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--text-link);
}

.card .read-more:hover {
  color: var(--text-link-hover);
  text-decoration: underline;
}

.article-list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  gap: 24px;
  margin-top: 24px;
}

.article-item {
  background-color: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: 18px;
  padding: 24px;
  transition: box-shadow 0.3s ease, border-color 0.3s ease, background-color 0.3s ease, transform 0.3s ease;
  box-shadow: var(--shadow-sm);
  position: relative;
  overflow: hidden;
}

.article-item::after {
  content: '';
  position: absolute;
  inset: 0;
  background: var(--gradient-accent);
  opacity: 0;
  transition: opacity 0.3s ease;
  pointer-events: none;
  mix-blend-mode: overlay;
}

.article-item:hover {
  box-shadow: var(--shadow-lg);
  border-color: var(--brand);
  transform: translateY(-4px);
}

.article-item:hover::after {
  opacity: 0.06;
}

.article-item h3 {
  font-size: 1.15rem;
  margin-top: 0;
  margin-bottom: 0.5rem;
  color: var(--text-primary);
}

.article-item .article-date {
  font-size: 0.82rem;
  color: var(--text-muted);
  margin-bottom: 0.5rem;
}

.article-item .article-summary {
  font-size: 0.92rem;
  color: var(--text-body);
  margin-bottom: 0.75rem;
}

.article-item .read-more {
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--text-link);
}

.article-item .read-more:hover {
  color: var(--text-link-hover);
  text-decoration: underline;
}

.faq-list {
  margin-top: 24px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.faq-item {
  background: var(--glass-bg);
  -webkit-backdrop-filter: var(--glass-blur);
  backdrop-filter: var(--glass-blur);
  border: 1px solid var(--glass-border);
  border-radius: 14px;
  overflow: hidden;
  transition: border-color 0.3s ease, background-color 0.3s ease, box-shadow 0.3s ease;
}

.faq-item:hover {
  border-color: var(--brand);
  box-shadow: var(--shadow-md);
}

.faq-item.open {
  border-color: var(--brand);
  box-shadow: var(--shadow-md);
}

.faq-question {
  width: 100%;
  background: none;
  border: none;
  text-align: left;
  padding: 18px 24px;
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-faq-q);
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  transition: background-color 0.2s ease, color 0.3s ease;
  font-family: inherit;
  line-height: 1.5;
}

.faq-question:hover {
  background-color: var(--bg-elevated);
}

.faq-question .faq-icon {
  font-size: 1.4rem;
  font-weight: 400;
  color: var(--brand-deep);
  transition: transform 0.3s ease;
  flex-shrink: 0;
  line-height: 1;
}

.faq-item.open .faq-icon {
  transform: rotate(45deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s ease, padding 0.3s ease;
  padding: 0 24px;
}

.faq-item.open .faq-answer {
  max-height: 600px;
  padding: 0 24px 20px 24px;
}

.faq-answer p {
  color: var(--text-faq-a);
  font-size: 0.95rem;
  margin-bottom: 0.5rem;
}

.howto-steps {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
  margin-top: 24px;
}

.howto-step {
  background-color: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: 16px;
  padding: 24px;
  position: relative;
  transition: background-color 0.3s ease, border-color 0.3s ease, transform 0.3s ease, box-shadow 0.3s ease;
}

.howto-step:hover {
  transform: translateY(-5px);
  border-color: var(--brand);
  box-shadow: var(--shadow-lg);
}

.howto-step .step-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: var(--gradient-brand);
  color: #ffffff;
  font-weight: 700;
  font-size: 1rem;
  margin-bottom: 12px;
  box-shadow: 0 6px 16px -6px rgba(37, 99, 235, 0.6);
}

.howto-step h4 {
  font-size: 1.1rem;
  margin-top: 0;
  color: var(--text-primary);
}

.howto-step p {
  font-size: 0.92rem;
  color: var(--text-body);
}

.table-wrap {
  overflow-x: auto;
  margin-top: 24px;
  border-radius: 16px;
  border: 1px solid var(--border-light);
  box-shadow: var(--shadow-sm);
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.95rem;
}

thead {
  background: var(--gradient-brand);
}

th {
  padding: 14px 20px;
  text-align: left;
  font-weight: 700;
  color: #ffffff;
  border-bottom: 2px solid var(--border-medium);
  white-space: nowrap;
}

td {
  padding: 12px 20px;
  color: var(--text-body);
  border-bottom: 1px solid var(--border-light);
}

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

tbody tr {
  transition: background-color 0.2s ease;
}

tbody tr:hover {
  background-color: var(--bg-elevated);
}

.breadcrumb {
  padding: 16px 0;
  font-size: 0.88rem;
  color: var(--text-muted);
}

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

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

.breadcrumb span {
  color: var(--text-muted);
  margin: 0 6px;
}

.tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 16px;
}

.tag {
  display: inline-block;
  background-color: var(--bg-tag);
  color: var(--text-secondary);
  font-size: 0.82rem;
  padding: 4px 14px;
  border-radius: 20px;
  font-weight: 500;
  transition: background-color 0.3s ease, color 0.3s ease, transform 0.2s ease;
}

.tag:hover {
  transform: translateY(-2px);
  background: var(--gradient-brand);
  color: #ffffff;
}

footer {
  background-color: var(--bg-footer);
  color: var(--text-footer);
  padding: 48px 0 24px;
  transition: background-color 0.3s ease, color 0.3s ease;
  position: relative;
}

footer::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--gradient-brand);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1.5fr;
  gap: 40px;
  margin-bottom: 36px;
}

.footer-col h4 {
  color: var(--text-footer-heading);
  font-size: 1.05rem;
  margin-bottom: 16px;
  margin-top: 0;
}

.footer-col p {
  color: var(--text-footer);
  font-size: 0.9rem;
  line-height: 1.7;
}

.footer-col ul {
  list-style: none;
}

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

.footer-col ul li a {
  color: var(--text-footer);
  font-size: 0.9rem;
  transition: color 0.2s ease, padding-left 0.2s ease;
}

.footer-col ul li a:hover {
  color: #ffffff;
  text-decoration: underline;
  padding-left: 4px;
}

.footer-bottom {
  border-top: 1px solid var(--border-dark);
  padding-top: 20px;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  font-size: 0.85rem;
  color: var(--text-footer);
}

.footer-bottom a {
  color: var(--text-footer);
}

.footer-bottom a:hover {
  color: #ffffff;
}

.back-to-top {
  position: fixed;
  bottom: 32px;
  right: 32px;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--gradient-brand);
  color: #ffffff;
  border: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 8px 24px -6px rgba(37, 99, 235, 0.6);
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s ease, visibility 0.3s ease, transform 0.3s ease, box-shadow 0.3s ease;
  z-index: 999;
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
}

.back-to-top:hover {
  transform: translateY(-4px) scale(1.06);
  box-shadow: 0 14px 32px -6px rgba(37, 99, 235, 0.8);
}

.back-to-top svg {
  width: 24px;
  height: 24px;
  fill: #ffffff;
}

.fade-in {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

.contact-form {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-top: 24px;
  background: var(--glass-bg);
  -webkit-backdrop-filter: var(--glass-blur);
  backdrop-filter: var(--glass-blur);
  border: 1px solid var(--glass-border);
  border-radius: 20px;
  padding: 28px;
  box-shadow: var(--shadow-sm);
}

.contact-form .full-width {
  grid-column: 1 / -1;
}

.contact-form label {
  display: block;
  font-weight: 600;
  font-size: 0.9rem;
  margin-bottom: 6px;
  color: var(--text-primary);
}

.contact-form input,
.contact-form textarea {
  width: 100%;
  padding: 12px 16px;
  border: 1px solid var(--border-medium);
  border-radius: 12px;
  font-size: 0.95rem;
  font-family: inherit;
  background-color: var(--bg-surface);
  color: var(--text-body);
  transition: border-color 0.2s ease, background-color 0.3s ease, color 0.3s ease, box-shadow 0.25s ease;
}

.contact-form input::placeholder,
.contact-form textarea::placeholder {
  color: var(--text-placeholder);
  opacity: 1;
}

.contact-form input:focus,
.contact-form textarea:focus {
  outline: none;
  border-color: var(--brand);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.12);
}

.contact-form textarea {
  min-height: 120px;
  resize: vertical;
}

.contact-form button {
  background: var(--gradient-brand);
  color: #ffffff;
  border: none;
  border-radius: 40px;
  padding: 14px 36px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: filter 0.2s ease, transform 0.2s ease, box-shadow 0.25s ease;
  font-family: inherit;
  box-shadow: 0 8px 24px -8px rgba(37, 99, 235, 0.6);
}

.contact-form button:hover {
  filter: brightness(1.1);
  transform: translateY(-2px);
  box-shadow: 0 14px 32px -8px rgba(37, 99, 235, 0.8);
}

.text-muted {
  color: var(--text-muted);
}

.text-small {
  font-size: 0.88rem;
}

.mt-2 { margin-top: 16px; }
.mt-3 { margin-top: 24px; }
.mb-2 { margin-bottom: 16px; }
.mb-3 { margin-bottom: 24px; }

.info-box {
  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);
  padding: 20px 24px;
  border-radius: 0 16px 16px 0;
  margin: 20px 0;
  transition: background-color 0.3s ease, box-shadow 0.3s ease;
}

.info-box:hover {
  box-shadow: var(--shadow-md);
}

.info-box p {
  margin-bottom: 0;
  color: var(--text-body);
}

.author-info {
  display: flex;
  align-items: center;
  gap: 16px;
  background: var(--glass-bg);
  -webkit-backdrop-filter: var(--glass-blur);
  backdrop-filter: var(--glass-blur);
  border: 1px solid var(--glass-border);
  padding: 20px 24px;
  border-radius: 18px;
  margin-top: 32px;
  transition: background-color 0.3s ease, box-shadow 0.3s ease, transform 0.3s ease;
}

.author-info:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-3px);
}

.author-avatar {
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: var(--gradient-brand);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #ffffff;
  font-weight: 700;
  font-size: 1.3rem;
  flex-shrink: 0;
  box-shadow: 0 6px 18px -6px rgba(37, 99, 235, 0.7);
}

.author-info .author-detail {
  font-size: 0.9rem;
  color: var(--text-body);
}

.author-info .author-detail strong {
  color: var(--text-primary);
}

.anchor-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 20px 0;
  padding: 16px 20px;
  background: var(--glass-bg);
  -webkit-backdrop-filter: var(--glass-blur);
  backdrop-filter: var(--glass-blur);
  border: 1px solid var(--glass-border);
  border-radius: 16px;
  transition: background-color 0.3s ease;
}

.anchor-nav a {
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--text-link);
  padding: 4px 12px;
  border-radius: 20px;
  background-color: var(--bg-surface);
  border: 1px solid var(--border-light);
  transition: background-color 0.25s ease, border-color 0.25s ease, color 0.25s ease, transform 0.2s ease, box-shadow 0.25s ease;
}

.anchor-nav a:hover {
  background: var(--gradient-brand);
  color: #ffffff;
  border-color: transparent;
  text-decoration: none;
  transform: translateY(-2px);
  box-shadow: var(--shadow-glow);
}

@media (max-width: 1024px) {
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
  .stats-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  h1 { font-size: 1.8rem; }
  h2 { font-size: 1.5rem; }
  h3 { font-size: 1.2rem; }

  .nav-menu {
    display: none;
    position: absolute;
    top: 68px;
    left: 0;
    right: 0;
    background-color: var(--bg-nav);
    -webkit-backdrop-filter: var(--glass-blur);
    backdrop-filter: var(--glass-blur);
    flex-direction: column;
    padding: 20px 24px;
    gap: 16px;
    border-bottom: 1px solid var(--border-light);
    box-shadow: var(--shadow-md);
  }

  .nav-menu.open {
    display: flex;
    animation: menuSlide 0.3s ease both;
  }

  @keyframes menuSlide {
    from {
      opacity: 0;
      transform: translateY(-12px);
    }
    to {
      opacity: 1;
      transform: translateY(0);
    }
  }

  .mobile-menu-btn {
    display: flex;
  }

  .search-box input {
    width: 100px;
  }

  .banner-content h1 {
    font-size: 1.9rem;
  }

  .banner-content p {
    font-size: 1rem;
  }

  .banner {
    min-height: 380px;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 28px;
  }

  .stats-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
  }

  .stat-item .stat-number {
    font-size: 2rem;
  }

  .article-list {
    grid-template-columns: 1fr;
  }

  .card-grid {
    grid-template-columns: 1fr;
  }

  .howto-steps {
    grid-template-columns: 1fr;
  }

  .back-to-top {
    bottom: 20px;
    right: 20px;
    width: 42px;
    height: 42px;
  }
}

@media (max-width: 600px) {
  .contact-form {
    grid-template-columns: 1fr;
    padding: 20px;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 16px;
  }
  .banner-content h1 {
    font-size: 1.5rem;
  }
  .banner-content p {
    font-size: 0.92rem;
  }
  .search-box {
    display: none;
  }
  .nav-actions {
    gap: 8px;
  }
  .banner {
    min-height: 340px;
  }
  .banner-btn {
    padding: 10px 24px;
    font-size: 0.92rem;
  }
}

@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;
  }
  .fade-in {
    opacity: 1;
    transform: none;
  }
}