:root {
  --bg: #f8f9fa;
  --bg-alt: #ffffff;
  --text: #222;
  --text-muted: #666;
  --text-faint: #999;
  --primary: #1a1a2e;
  --primary-alt: #16213e;
  --accent: #e94560;
  --accent-soft: rgba(233, 69, 96, 0.12);
  --border: #eaeaea;
  --card-bg: #ffffff;
  --header-bg: #1a1a2e;
  --header-text: #ffffff;
  --header-link: #d5d5e0;
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.06);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 16px 40px rgba(0, 0, 0, 0.16);
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --glass-bg: rgba(255, 255, 255, 0.65);
  --glass-border: rgba(255, 255, 255, 0.4);
  --link: #1a73e8;
  --link-hover: #0d47a1;
  --transition: 0.28s cubic-bezier(0.4, 0, 0.2, 1);
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f0f1a;
    --bg-alt: #16162a;
    --text: #e6e6f0;
    --text-muted: #a8a8c0;
    --text-faint: #7a7a94;
    --primary: #e6e6f0;
    --primary-alt: #c8c8dd;
    --accent: #ff6b81;
    --accent-soft: rgba(255, 107, 129, 0.14);
    --border: #2a2a44;
    --card-bg: #1c1c34;
    --header-bg: #0a0a14;
    --header-text: #f0f0fa;
    --header-link: #b0b0c8;
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.4);
    --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.5);
    --shadow-lg: 0 16px 40px rgba(0, 0, 0, 0.6);
    --glass-bg: rgba(28, 28, 52, 0.6);
    --glass-border: rgba(255, 255, 255, 0.08);
    --link: #6ea8fe;
    --link-hover: #9ec5fe;
  }
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: 80px;
}

body {
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: background var(--transition), color var(--transition);
  overflow-x: hidden;
}

a {
  color: var(--link);
  text-decoration: none;
  transition: color var(--transition);
}

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

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

header {
  background: var(--header-bg);
  color: var(--header-text);
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  box-shadow: 0 1px 0 rgba(255, 255, 255, 0.06);
}

header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.logo {
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--header-text);
  letter-spacing: 0.04em;
  background: linear-gradient(135deg, #ffffff 0%, #e94560 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  transition: opacity var(--transition);
}

.logo:hover {
  opacity: 0.85;
}

nav ul {
  display: flex;
  list-style: none;
  gap: 24px;
}

nav a {
  color: var(--header-link);
  font-size: 0.95rem;
  position: relative;
  padding: 4px 0;
  transition: color var(--transition);
}

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

nav a:hover {
  color: #ffffff;
  text-decoration: none;
}

nav a:hover::after {
  width: 100%;
}

.hero {
  position: relative;
  background: linear-gradient(135deg, #1a1a2e 0%, #16213e 45%, #0f3460 100%);
  color: #ffffff;
  padding: 90px 0 100px;
  text-align: center;
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  top: -30%;
  left: -10%;
  width: 60%;
  height: 160%;
  background: radial-gradient(circle, rgba(233, 69, 96, 0.28) 0%, transparent 65%);
  pointer-events: none;
}

.hero::after {
  content: "";
  position: absolute;
  bottom: -40%;
  right: -10%;
  width: 55%;
  height: 150%;
  background: radial-gradient(circle, rgba(15, 52, 96, 0.6) 0%, transparent 70%);
  pointer-events: none;
}

.hero .container {
  position: relative;
  z-index: 1;
}

.hero h1 {
  font-size: 2.2rem;
  margin-bottom: 16px;
  line-height: 1.35;
  letter-spacing: 0.02em;
  text-shadow: 0 2px 20px rgba(0, 0, 0, 0.3);
}

.hero p {
  font-size: 1.05rem;
  max-width: 700px;
  margin: 0 auto 28px;
  color: #c8c8dd;
}

.hero .btn {
  display: inline-block;
  background: linear-gradient(135deg, #e94560 0%, #c81e45 100%);
  color: #ffffff;
  padding: 13px 36px;
  border-radius: var(--radius-md);
  font-size: 1rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  box-shadow: 0 8px 24px rgba(233, 69, 96, 0.4);
  transition: transform var(--transition), box-shadow var(--transition), background var(--transition);
}

.hero .btn:hover {
  transform: translateY(-3px);
  box-shadow: 0 14px 32px rgba(233, 69, 96, 0.55);
  text-decoration: none;
  color: #ffffff;
}

.hero .btn:active {
  transform: translateY(-1px);
}

.section {
  padding: 64px 0;
  position: relative;
  animation: fadeUp 0.6s ease both;
}

.section:nth-child(even) {
  background: var(--bg-alt);
}

.section h2 {
  font-size: 1.8rem;
  margin-bottom: 18px;
  color: var(--primary);
  border-left: 4px solid var(--accent);
  padding-left: 14px;
  line-height: 1.4;
  letter-spacing: 0.02em;
}

.section h3 {
  font-size: 1.3rem;
  margin: 28px 0 12px;
  color: var(--primary-alt);
  line-height: 1.5;
}

.section h4 {
  font-size: 1.1rem;
  margin: 18px 0 8px;
  color: var(--text-muted);
}

.section p {
  margin-bottom: 14px;
  color: var(--text-muted);
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 24px;
  margin-top: 28px;
}

.card {
  position: relative;
  background: var(--card-bg);
  border-radius: var(--radius-md);
  padding: 26px 24px;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border);
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
  overflow: hidden;
}

.card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: linear-gradient(90deg, var(--accent) 0%, #0f3460 100%);
  opacity: 0;
  transition: opacity var(--transition);
}

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

.card:hover::before {
  opacity: 1;
}

.card h3 {
  font-size: 1.15rem;
  margin: 0 0 10px;
  color: var(--primary);
}

.card p {
  font-size: 0.92rem;
  color: var(--text-muted);
  margin-bottom: 10px;
}

.card .meta {
  display: inline-block;
  font-size: 0.82rem;
  color: var(--accent);
  background: var(--accent-soft);
  padding: 3px 10px;
  border-radius: 999px;
  font-weight: 500;
}

.faq-item {
  border-bottom: 1px solid var(--border);
  padding: 18px 0;
  transition: background var(--transition);
}

.faq-item:hover {
  background: var(--accent-soft);
  border-radius: var(--radius-sm);
  padding-left: 12px;
  padding-right: 12px;
}

.faq-item h3 {
  font-size: 1.05rem;
  margin: 0 0 8px;
  color: var(--primary);
  cursor: default;
}

.faq-item p {
  font-size: 0.95rem;
  color: var(--text-muted);
}

.contact-info {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 16px;
  margin-top: 24px;
}

.contact-info div {
  background: var(--glass-bg);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid var(--glass-border);
  padding: 18px;
  border-radius: var(--radius-sm);
  font-size: 0.95rem;
  color: var(--text-muted);
  transition: transform var(--transition), box-shadow var(--transition);
}

.contact-info div:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-sm);
}

.contact-info strong {
  color: var(--primary);
}

footer {
  background: var(--header-bg);
  color: #a8a8c0;
  padding: 44px 0 28px;
  font-size: 0.9rem;
  line-height: 1.9;
}

footer a {
  color: #c8c8dd;
  transition: color var(--transition);
}

footer a:hover {
  color: #ffffff;
  text-decoration: none;
}

footer p {
  margin-bottom: 8px;
}

footer .footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
  margin-bottom: 20px;
  padding-bottom: 18px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.breadcrumb {
  font-size: 0.88rem;
  color: var(--text-faint);
  padding: 14px 0;
}

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

.article-list {
  list-style: none;
}

.article-list li {
  padding: 18px 0;
  border-bottom: 1px solid var(--border);
  transition: padding-left var(--transition), background var(--transition);
}

.article-list li:hover {
  padding-left: 10px;
  background: var(--accent-soft);
  border-radius: var(--radius-sm);
}

.article-list li h3 {
  font-size: 1.05rem;
  margin-bottom: 4px;
  color: var(--primary);
}

.article-list li h3 a {
  color: var(--primary);
}

.article-list li h3 a:hover {
  color: var(--accent);
  text-decoration: none;
}

.article-list li .meta {
  font-size: 0.82rem;
  color: var(--text-faint);
}

.article-list li p {
  font-size: 0.92rem;
  color: var(--text-muted);
  margin-top: 6px;
}

.back-top {
  position: fixed;
  bottom: 32px;
  right: 32px;
  background: linear-gradient(135deg, #1a1a2e 0%, #0f3460 100%);
  color: #ffffff;
  width: 46px;
  height: 46px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  cursor: pointer;
  opacity: 0;
  transition: opacity var(--transition), transform var(--transition), box-shadow var(--transition);
  pointer-events: none;
  box-shadow: var(--shadow-md);
  z-index: 90;
}

.back-top.show {
  opacity: 1;
  pointer-events: auto;
}

.back-top:hover {
  transform: translateY(-4px) scale(1.05);
  box-shadow: var(--shadow-lg);
}

.search-box {
  display: flex;
  gap: 10px;
  margin: 28px 0;
  padding: 8px;
  background: var(--glass-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
}

.search-box input {
  flex: 1;
  padding: 11px 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 1rem;
  background: var(--bg-alt);
  color: var(--text);
  outline: none;
  transition: border-color var(--transition), box-shadow var(--transition);
}

.search-box input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft);
}

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

.search-box button {
  padding: 11px 24px;
  background: linear-gradient(135deg, #1a1a2e 0%, #0f3460 100%);
  color: #ffffff;
  border: none;
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: 1rem;
  font-weight: 500;
  transition: transform var(--transition), box-shadow var(--transition), opacity var(--transition);
}

.search-box button:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 18px rgba(15, 52, 96, 0.35);
  opacity: 0.95;
}

.search-box button:active {
  transform: translateY(0);
}

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

@media (max-width: 768px) {
  html {
    scroll-padding-top: 72px;
  }

  header .container {
    height: 58px;
  }

  .logo {
    font-size: 1.2rem;
  }

  nav ul {
    display: none;
  }

  .hero {
    padding: 64px 0 72px;
  }

  .hero h1 {
    font-size: 1.55rem;
  }

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

  .hero .btn {
    padding: 11px 28px;
    font-size: 0.95rem;
  }

  .section {
    padding: 44px 0;
  }

  .section h2 {
    font-size: 1.4rem;
  }

  .section h3 {
    font-size: 1.15rem;
  }

  .grid {
    grid-template-columns: 1fr;
    gap: 18px;
  }

  .contact-info {
    grid-template-columns: 1fr;
  }

  .search-box {
    flex-direction: column;
  }

  .search-box button {
    width: 100%;
  }

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

  .faq-item:hover {
    padding-left: 8px;
    padding-right: 8px;
  }

  .article-list li:hover {
    padding-left: 6px;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 14px;
  }

  .hero h1 {
    font-size: 1.35rem;
  }

  .section h2 {
    font-size: 1.25rem;
  }

  .card {
    padding: 20px 18px;
  }
}

@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;
  }
}