:root {
  --bg-body: #f7f9fc;
  --bg-card: #ffffff;
  --bg-nav: rgba(255, 255, 255, 0.82);
  --bg-footer: #1a2a3a;
  --bg-banner-overlay: rgba(10, 20, 35, 0.72);
  --bg-tag: #e8eef5;
  --bg-table-header: #e2e8f0;
  --bg-table-row-alt: #f1f5f9;
  --bg-input: rgba(255, 255, 255, 0.9);
  --bg-faq-active: #f0f5fa;
  --bg-glass: rgba(255, 255, 255, 0.62);
  --bg-glass-border: rgba(255, 255, 255, 0.55);

  --text-primary: #17202a;
  --text-secondary: #243447;
  --text-muted: #3d4f5e;
  --text-light: #5a6b7a;
  --text-inverse: #f1f5f9;
  --text-link: #1a4d7a;
  --text-link-hover: #0d2f4f;
  --text-button: #ffffff;
  --text-heading: #0f1a24;
  --text-banner: #ffffff;

  --brand-primary: #1a4d7a;
  --brand-secondary: #2c6e9e;
  --brand-accent: #d4a843;
  --border-color: #d1d9e2;
  --border-light: #e2e8f0;

  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.1);

  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;

  --font-body: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
}

body.dark-mode {
  --bg-body: #0f1a24;
  --bg-card: #1a2a3a;
  --bg-nav: rgba(21, 34, 50, 0.82);
  --bg-footer: #0a121c;
  --bg-banner-overlay: rgba(0, 0, 0, 0.8);
  --bg-tag: #253545;
  --bg-table-header: #1e2e3e;
  --bg-table-row-alt: #162432;
  --bg-input: rgba(30, 46, 62, 0.9);
  --bg-faq-active: #1e2e3e;
  --bg-glass: rgba(26, 42, 58, 0.62);
  --bg-glass-border: rgba(90, 156, 201, 0.18);

  --text-primary: #e5e7eb;
  --text-secondary: #e2e8f0;
  --text-muted: #cbd5e1;
  --text-light: #94a3b8;
  --text-inverse: #0f1a24;
  --text-link: #7ab7e8;
  --text-link-hover: #a8d0f0;
  --text-heading: #ffffff;

  --brand-primary: #5a9cc9;
  --brand-secondary: #7ab7e8;
  --brand-accent: #e8c468;
  --border-color: #2e4258;
  --border-light: #253545;

  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.4);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.5);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.6);
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-body);
  background-color: var(--bg-body);
  color: var(--text-primary);
  line-height: 1.75;
  font-size: 16px;
  transition: background-color 0.3s ease, color 0.3s ease;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

.navbar {
  position: sticky;
  top: 0;
  z-index: 1000;
  background-color: var(--bg-nav);
  -webkit-backdrop-filter: saturate(180%) blur(16px);
  backdrop-filter: saturate(180%) blur(16px);
  border-bottom: 1px solid var(--bg-glass-border);
  box-shadow: var(--shadow-sm);
  transition: background-color 0.3s ease, border-color 0.3s ease;
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--text-heading);
  text-decoration: none;
  letter-spacing: 0.5px;
  transition: opacity 0.2s ease;
}

.nav-logo:hover {
  opacity: 0.85;
}

.nav-logo svg {
  width: 36px;
  height: 36px;
  border-radius: 8px;
  transition: transform 0.3s ease;
}

.nav-logo:hover svg {
  transform: rotate(-6deg) scale(1.05);
}

.nav-links {
  display: flex;
  list-style: none;
  gap: 6px;
  align-items: center;
}

.nav-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.95rem;
  padding: 8px 14px;
  border-radius: var(--radius-sm);
  transition: background-color 0.2s ease, color 0.2s ease, transform 0.2s ease;
  font-weight: 500;
  position: relative;
}

.nav-links a::after {
  content: "";
  position: absolute;
  left: 14px;
  right: 14px;
  bottom: 4px;
  height: 2px;
  background-color: var(--brand-accent);
  border-radius: 2px;
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 0.25s ease;
}

.nav-links a:hover,
.nav-links a:focus {
  background-color: var(--bg-tag);
  color: var(--text-heading);
  transform: translateY(-1px);
}

.nav-links a:hover::after,
.nav-links a:focus::after {
  transform: scaleX(1);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 10px;
}

.search-box {
  display: flex;
  align-items: center;
  background-color: var(--bg-input);
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
  border: 1px solid var(--border-color);
  border-radius: 22px;
  padding: 4px 6px 4px 16px;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.search-box:focus-within {
  border-color: var(--brand-primary);
  box-shadow: 0 0 0 3px rgba(26, 77, 122, 0.12);
}

.search-box input {
  border: none;
  background: transparent;
  outline: none;
  color: var(--text-primary);
  font-size: 0.9rem;
  width: 140px;
  font-family: var(--font-body);
}

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

.search-box button {
  background-color: var(--brand-primary);
  border: none;
  color: var(--text-button);
  border-radius: 18px;
  padding: 6px 14px;
  font-size: 0.85rem;
  cursor: pointer;
  transition: background-color 0.2s ease, transform 0.2s ease;
  font-family: var(--font-body);
  font-weight: 500;
}

.search-box button:hover {
  background-color: var(--brand-secondary);
  transform: scale(1.04);
}

.theme-toggle {
  background: none;
  border: 1px solid var(--border-color);
  border-radius: 50%;
  width: 40px;
  height: 40px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-secondary);
  transition: background-color 0.2s ease, border-color 0.2s ease, transform 0.3s ease;
}

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

.mobile-menu-btn {
  display: none;
  background: none;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  width: 40px;
  height: 40px;
  cursor: pointer;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 4px;
  padding: 8px;
}

.mobile-menu-btn span {
  display: block;
  width: 20px;
  height: 2px;
  background-color: var(--text-secondary);
  border-radius: 2px;
  transition: 0.3s;
}

.banner {
  position: relative;
  overflow: hidden;
  background-color: #0f1a24;
  min-height: 420px;
  display: flex;
  align-items: center;
}

.banner::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(26, 77, 122, 0.22) 0%, rgba(212, 168, 67, 0.1) 100%);
  pointer-events: none;
  z-index: 1;
}

.banner-slide {
  position: absolute;
  inset: 0;
  opacity: 0;
  transition: opacity 0.8s ease;
  display: flex;
  align-items: center;
  justify-content: center;
}

.banner-slide.active {
  opacity: 1;
}

.banner-slide svg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.banner-overlay {
  position: absolute;
  inset: 0;
  background: var(--bg-banner-overlay);
}

.banner-content {
  position: relative;
  z-index: 2;
  max-width: 1200px;
  margin: 0 auto;
  padding: 60px 20px;
  width: 100%;
  color: var(--text-banner);
}

.banner-content h1 {
  font-size: 2.6rem;
  font-weight: 800;
  line-height: 1.3;
  margin-bottom: 18px;
  color: #ffffff;
  text-shadow: 0 2px 12px rgba(0, 0, 0, 0.5);
  letter-spacing: 1px;
  animation: bannerFadeUp 0.9s ease both;
}

.banner-content p {
  font-size: 1.15rem;
  max-width: 700px;
  line-height: 1.8;
  color: #e2e8f0;
  text-shadow: 0 1px 8px rgba(0, 0, 0, 0.5);
  margin-bottom: 28px;
  animation: bannerFadeUp 0.9s 0.15s ease both;
}

.banner-badge {
  display: inline-block;
  background: linear-gradient(135deg, rgba(212, 168, 67, 0.95), rgba(232, 196, 104, 0.9));
  color: #1a2a3a;
  font-weight: 700;
  font-size: 0.85rem;
  padding: 6px 16px;
  border-radius: 20px;
  margin-bottom: 20px;
  letter-spacing: 1px;
  box-shadow: 0 4px 14px rgba(212, 168, 67, 0.35);
  animation: bannerFadeUp 0.9s 0.05s ease both;
}

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

.banner-dots {
  position: absolute;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  gap: 10px;
  z-index: 3;
}

.banner-dots button {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  border: 2px solid rgba(255, 255, 255, 0.7);
  background: transparent;
  cursor: pointer;
  transition: background-color 0.3s ease, transform 0.3s ease, width 0.3s ease;
  padding: 0;
}

.banner-dots button.active {
  background-color: #ffffff;
  border-color: #ffffff;
  width: 28px;
  border-radius: 8px;
}

.banner-dots button:hover {
  transform: scale(1.2);
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

.section {
  padding: 64px 0;
}

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

.section-header {
  text-align: center;
  margin-bottom: 44px;
}

.section-header h2 {
  font-size: 2rem;
  font-weight: 700;
  color: var(--text-heading);
  margin-bottom: 12px;
  letter-spacing: 0.5px;
}

.section-header p {
  font-size: 1.05rem;
  color: var(--text-muted);
  max-width: 700px;
  margin: 0 auto;
  line-height: 1.8;
}

.section-header .divider {
  width: 56px;
  height: 4px;
  background: linear-gradient(90deg, var(--brand-primary), var(--brand-accent));
  border-radius: 2px;
  margin: 16px auto 0;
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 24px;
}

.card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 28px 24px;
  box-shadow: var(--shadow-sm);
  transition: box-shadow 0.25s ease, transform 0.25s ease, border-color 0.25s ease;
  position: relative;
  overflow: hidden;
}

.card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--brand-primary), var(--brand-accent));
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 0.35s ease;
}

.card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-4px);
  border-color: var(--brand-secondary);
}

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

.card-icon {
  width: 48px;
  height: 48px;
  margin-bottom: 18px;
  transition: transform 0.3s ease;
}

.card:hover .card-icon {
  transform: scale(1.08) rotate(-3deg);
}

.card h3 {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-heading);
  margin-bottom: 10px;
}

.card p {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.75;
}

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

.article-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: box-shadow 0.25s ease, transform 0.25s ease;
  display: flex;
  flex-direction: column;
}

.article-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-4px);
}

.article-thumb {
  width: 100%;
  height: 180px;
  background-color: var(--bg-tag);
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  position: relative;
}

.article-thumb svg {
  width: 100%;
  height: 100%;
  transition: transform 0.5s ease;
}

.article-card:hover .article-thumb svg {
  transform: scale(1.06);
}

.article-body {
  padding: 22px 22px 24px;
  flex: 1;
  display: flex;
  flex-direction: column;
}

.article-meta {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 0.82rem;
  color: var(--text-light);
  margin-bottom: 10px;
}

.article-meta .tag {
  background-color: var(--bg-tag);
  color: var(--text-secondary);
  padding: 2px 10px;
  border-radius: 12px;
  font-size: 0.78rem;
  font-weight: 500;
  transition: background-color 0.2s ease, color 0.2s ease;
}

.article-card:hover .article-meta .tag {
  background-color: var(--brand-primary);
  color: #ffffff;
}

.article-body h3 {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-heading);
  margin-bottom: 10px;
  line-height: 1.5;
  transition: color 0.2s ease;
}

.article-card:hover .article-body h3 {
  color: var(--brand-primary);
}

.article-body p {
  font-size: 0.92rem;
  color: var(--text-secondary);
  line-height: 1.75;
  flex: 1;
  margin-bottom: 16px;
}

.article-link {
  color: var(--text-link);
  text-decoration: none;
  font-weight: 600;
  font-size: 0.9rem;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  transition: color 0.2s ease, gap 0.2s ease;
  align-self: flex-start;
}

.article-link:hover {
  color: var(--text-link-hover);
  text-decoration: underline;
  gap: 8px;
}

.stats-row {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 24px;
  margin-top: 40px;
}

.stat-item {
  text-align: center;
  padding: 28px 16px;
  background-color: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  transition: box-shadow 0.25s ease, transform 0.25s ease;
}

.stat-item:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-3px);
}

.stat-number {
  font-size: 2.4rem;
  font-weight: 800;
  color: var(--brand-primary);
  line-height: 1.2;
  margin-bottom: 6px;
  background: linear-gradient(135deg, var(--brand-primary), var(--brand-accent));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.stat-label {
  font-size: 0.92rem;
  color: var(--text-muted);
  font-weight: 500;
}

.faq-list {
  max-width: 860px;
  margin: 0 auto;
}

.faq-item {
  background-color: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  margin-bottom: 12px;
  overflow: hidden;
  transition: border-color 0.2s ease, background-color 0.2s ease, box-shadow 0.2s ease;
}

.faq-item.active {
  border-color: var(--brand-secondary);
  background-color: var(--bg-faq-active);
  box-shadow: var(--shadow-sm);
}

.faq-question {
  width: 100%;
  background: none;
  border: none;
  padding: 20px 24px;
  text-align: left;
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-heading);
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  font-family: var(--font-body);
  line-height: 1.6;
  transition: color 0.2s ease;
}

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

.faq-question .arrow {
  flex-shrink: 0;
  width: 22px;
  height: 22px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform 0.3s ease;
  color: var(--text-muted);
}

.faq-item.active .faq-question .arrow {
  transform: rotate(180deg);
  color: var(--brand-primary);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s ease, padding 0.35s ease;
  padding: 0 24px;
}

.faq-item.active .faq-answer {
  max-height: 500px;
  padding: 0 24px 22px;
}

.faq-answer p {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.85;
}

.howto-steps {
  max-width: 800px;
  margin: 0 auto;
  counter-reset: step;
}

.howto-step {
  display: flex;
  gap: 20px;
  margin-bottom: 28px;
  position: relative;
  transition: transform 0.25s ease;
}

.howto-step:hover {
  transform: translateX(6px);
}

.howto-step::before {
  counter-increment: step;
  content: counter(step);
  flex-shrink: 0;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--brand-primary), var(--brand-secondary));
  color: #ffffff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 1.1rem;
  box-shadow: 0 2px 8px rgba(26, 77, 122, 0.3);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.howto-step:hover::before {
  transform: scale(1.1);
  box-shadow: 0 4px 16px rgba(26, 77, 122, 0.45);
}

.howto-step-content h3 {
  font-size: 1.08rem;
  font-weight: 700;
  color: var(--text-heading);
  margin-bottom: 4px;
}

.howto-step-content p {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.75;
}

.table-wrap {
  overflow-x: auto;
  margin-top: 24px;
  border-radius: var(--radius-md);
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.92rem;
  background-color: var(--bg-card);
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}

thead th {
  background-color: var(--bg-table-header);
  color: var(--text-heading);
  font-weight: 700;
  padding: 14px 18px;
  text-align: left;
  border-bottom: 2px solid var(--border-color);
}

tbody td {
  padding: 13px 18px;
  color: var(--text-secondary);
  border-bottom: 1px solid var(--border-light);
  transition: background-color 0.2s ease;
}

tbody tr:nth-child(even) {
  background-color: var(--bg-table-row-alt);
}

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

.team-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 24px;
}

.team-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 28px 20px;
  text-align: center;
  box-shadow: var(--shadow-sm);
  transition: box-shadow 0.25s ease, transform 0.25s ease;
}

.team-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-4px);
}

.team-avatar {
  width: 80px;
  height: 80px;
  border-radius: 50%;
  margin: 0 auto 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.8rem;
  font-weight: 700;
  color: #ffffff;
  background-color: var(--brand-primary);
  box-shadow: 0 4px 14px rgba(26, 77, 122, 0.25);
  transition: transform 0.3s ease;
}

.team-card:hover .team-avatar {
  transform: scale(1.08);
}

.team-card h3 {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-heading);
  margin-bottom: 4px;
}

.team-card .role {
  font-size: 0.85rem;
  color: var(--text-light);
  margin-bottom: 10px;
}

.team-card p {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

.contact-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 24px;
}

.contact-item {
  background-color: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 28px 22px;
  text-align: center;
  box-shadow: var(--shadow-sm);
  transition: box-shadow 0.25s ease, transform 0.25s ease;
}

.contact-item:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-4px);
}

.contact-item svg {
  width: 40px;
  height: 40px;
  margin-bottom: 14px;
  transition: transform 0.3s ease;
}

.contact-item:hover svg {
  transform: scale(1.1) rotate(4deg);
}

.contact-item h3 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-heading);
  margin-bottom: 6px;
}

.contact-item p {
  font-size: 0.92rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

.footer {
  background-color: var(--bg-footer);
  color: var(--text-inverse);
  padding: 56px 0 0;
  transition: background-color 0.3s ease;
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 36px;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

.footer-col h4 {
  font-size: 1rem;
  font-weight: 700;
  color: #ffffff;
  margin-bottom: 16px;
  letter-spacing: 0.5px;
  position: relative;
  padding-bottom: 10px;
}

.footer-col h4::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 32px;
  height: 2px;
  background-color: var(--brand-accent);
  border-radius: 2px;
}

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

.footer-col ul li {
  margin-bottom: 10px;
}

.footer-col ul li a {
  color: #cbd5e1;
  text-decoration: none;
  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-col p {
  color: #cbd5e1;
  font-size: 0.9rem;
  line-height: 1.8;
  margin-bottom: 8px;
}

.footer-bottom {
  margin-top: 44px;
  border-top: 1px solid rgba(255, 255, 255, 0.12);
  padding: 22px 20px;
  text-align: center;
}

.footer-bottom p {
  font-size: 0.85rem;
  color: #94a3b8;
  line-height: 1.8;
}

.footer-bottom a {
  color: #cbd5e1;
  text-decoration: none;
  margin: 0 8px;
  transition: color 0.2s ease;
}

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

.back-to-top {
  position: fixed;
  bottom: 30px;
  right: 30px;
  width: 46px;
  height: 46px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--brand-primary), var(--brand-secondary));
  color: #ffffff;
  border: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-md);
  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.show {
  opacity: 1;
  visibility: visible;
}

.back-to-top:hover {
  transform: translateY(-4px) scale(1.06);
  box-shadow: var(--shadow-lg);
}

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

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

.breadcrumb {
  max-width: 1200px;
  margin: 0 auto;
  padding: 14px 20px 0;
  font-size: 0.85rem;
  color: var(--text-light);
}

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

.breadcrumb a:hover {
  text-decoration: underline;
}

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

.author-info {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 18px 22px;
  background-color: var(--bg-tag);
  border-radius: var(--radius-md);
  margin-top: 32px;
  border: 1px solid var(--border-light);
  transition: box-shadow 0.25s ease;
}

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

.author-avatar {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--brand-primary), var(--brand-secondary));
  display: flex;
  align-items: center;
  justify-content: center;
  color: #ffffff;
  font-weight: 700;
  font-size: 1.1rem;
  flex-shrink: 0;
  box-shadow: 0 2px 8px rgba(26, 77, 122, 0.25);
}

.author-text h4 {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-heading);
  margin-bottom: 2px;
}

.author-text p {
  font-size: 0.85rem;
  color: var(--text-muted);
  line-height: 1.6;
}

a:focus-visible,
button:focus-visible {
  outline: 2px solid var(--brand-accent);
  outline-offset: 2px;
}

::-webkit-scrollbar {
  width: 10px;
}

::-webkit-scrollbar-track {
  background: var(--bg-body);
}

::-webkit-scrollbar-thumb {
  background: var(--border-color);
  border-radius: 5px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--text-light);
}

@media (max-width: 900px) {
  .nav-links {
    display: none;
    position: absolute;
    top: 68px;
    left: 0;
    right: 0;
    background-color: var(--bg-nav);
    -webkit-backdrop-filter: saturate(180%) blur(16px);
    backdrop-filter: saturate(180%) blur(16px);
    flex-direction: column;
    padding: 16px 20px;
    border-bottom: 1px solid var(--border-color);
    box-shadow: var(--shadow-md);
    gap: 4px;
  }

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

  @keyframes menuSlide {
    from {
      opacity: 0;
      transform: translateY(-10px);
    }
    to {
      opacity: 1;
      transform: translateY(0);
    }
  }

  .nav-links a {
    width: 100%;
    padding: 12px 14px;
  }

  .nav-links a::after {
    display: none;
  }

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

  .search-box {
    display: none;
  }

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

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

  .section-header h2 {
    font-size: 1.6rem;
  }

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

@media (max-width: 600px) {
  .banner-content h1 {
    font-size: 1.5rem;
  }

  .banner {
    min-height: 340px;
  }

  .section {
    padding: 44px 0;
  }

  .stat-number {
    font-size: 1.9rem;
  }

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

  .author-info {
    flex-direction: column;
    text-align: center;
  }
}