:root {
  --bg: #0f1218;
  --bg-alt: #181c25;
  --text: #f9fafb;
  --text-secondary: #9ca3af;
  --border: #2d3748;
  --primary: #f59e0b;
  --primary-hover: #fbbf24;
  --card-bg: #1e293b;
  --shadow: 0 18px 45px rgba(0, 0, 0, .22);
  --orange-banner: #f59e0b;
  --footer-bg: #171a29;
  --dark-bg: #181822;
  --dark-card: #242435;
  --dark-border: #333348;
  scroll-padding-top: 80px;
  scroll-behavior: smooth;
}

[data-theme="light"] {
  --bg: #ffffff;
  --bg-alt: #fafafa;
  --text: #111827;
  --text-secondary: #6b7280;
  --border: #e5e7eb;
  --primary: #f59e0b;
  --primary-hover: #d97706;
  --card-bg: #ffffff;
  --shadow: 0 18px 45px rgba(0, 0, 0, .08);
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
}

body {
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  transition: background .22s, color .22s;
}

a {
  color: inherit;
  text-decoration: none;
}

select.btn {
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%23666' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 8px center;
  padding-right: 28px;
}

/* 导航栏 */
.topbar {
  height: 56px;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 24px;
  background: var(--bg);
  position: sticky;
  top: 0;
  z-index: 10;
}

.logo {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 600;
  font-size: 18px;
}

.logo-mark {
  width: 32px;
  height: 32px;
  border-radius: 6px;
  background: linear-gradient(135deg, #f59e0b, #9333ea);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-weight: bold;
  font-size: 18px;
}

.nav-links {
  display: flex;
  gap: 24px;
  font-size: 14px;
  color: var(--text-secondary);
}

.nav-links a:hover {
  color: var(--text);
}
.nav-links a.active {
  color: var(--primary);
}

.top-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

.btn {
  border: 1px solid var(--border);
  background: transparent;
  color: var(--text);
  padding: 8px 14px;
  border-radius: 6px;
  font-size: 14px;
  cursor: pointer;
  transition: .18s;
}

.btn:hover {
  background: var(--bg-alt);
}

.btn-primary {
  background: var(--primary);
  border-color: var(--primary);
  color: white;
}

.btn-primary:hover {
  background: var(--primary-hover);
}

/* 首屏 */
.hero {
  max-width: 1280px;
  margin: 0 auto;
  padding: 48px 24px 32px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
}

.hero h1 {
  font-size: 38px;
  line-height: 1.25;
  margin-bottom: 16px;
}

.hero p {
  color: var(--text-secondary);
  font-size: 16px;
  margin-bottom: 24px;
}

.hero-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

.preview {
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 18px;
  box-shadow: var(--shadow);
  min-height: 260px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-secondary);
  font-size: 15px;
}

/* 通用区块 */
.section {
  max-width: 1280px;
  margin: 0 auto;
  padding: 48px 24px;
}

.section-title {
  text-align: center;
  margin-bottom: 32px;
}

.section-title h2 {
  font-size: 28px;
  margin-bottom: 8px;
}

.section-title p {
  color: var(--text-secondary);
  max-width: 640px;
  margin: 0 auto;
}

.cards {
  display: grid;
  grid-template-columns: repeat(3, minmax(280px, 1fr));
  gap: 16px;
}

.card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 20px;
  transition: .2s;
}

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

.card h3 {
  font-size: 18px;
  margin-bottom: 10px;
}

.card p {
  color: var(--text-secondary);
  font-size: 14px;
  line-height: 1.7;
}

/* 页脚 */
footer {
  background: #171a29;
  color: #e9e9e9;
  padding: 60px 24px 32px;
  margin-top: 60px;
}
.footer-wrap {
  max-width: 1280px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
  margin-bottom: 40px;
}
.footer-col h4 {
  font-size: 18px;
  margin-bottom: 20px;
  color: #ffffff;
}
.footer-col a {
  display: block;
  font-size: 15px;
  color: #b0b8d4;
  margin-bottom: 12px;
}
.footer-col a:hover {
  color: #ffffff;
}
.copyright {
  max-width: 1280px;
  margin: 0 auto;
  text-align: center;
  font-size: 14px;
  color: #a0a8c4;
  padding-top: 24px;
}

/* 移动端 */
@media (max-width: 900px) {
  .hero {
    grid-template-columns: 1fr;
  }
  .cards {
    grid-template-columns: repeat(2, 1fr);
  }
  .nav-links {
    gap: 12px;
  }
}
@media (max-width: 600px) {
  .cards {
    grid-template-columns: 1fr;
  }
  .nav-links {
    display: none;
  }
}