/* 小蓝APP下载官网 - xlt.baby */
:root {
  --primary: #1a8cff;
  --primary-dark: #0066cc;
  --accent: #ff6b35;
  --text: #1a1a2e;
  --text-light: #5a5a72;
  --bg: #f5f7fb;
  --white: #ffffff;
  --border: #e2e8f0;
  --shadow: 0 4px 20px rgba(26, 140, 255, 0.08);
  --radius: 12px;
  --max-width: 1200px;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.75;
  font-size: 16px;
}

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

a:hover {
  color: var(--primary-dark);
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 20px;
}

/* Header */
.site-header {
  background: var(--white);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.04);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 20px;
  max-width: var(--max-width);
  margin: 0 auto;
}

.logo-link {
  display: flex;
  align-items: center;
  gap: 10px;
}

.logo-link img {
  width: 42px;
  height: 42px;
  border-radius: 10px;
}

.logo-text {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text);
}

.logo-text span {
  color: var(--primary);
}

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

.nav-menu a {
  color: var(--text);
  font-weight: 500;
  font-size: 0.95rem;
}

.nav-menu a:hover,
.nav-menu a.active {
  color: var(--primary);
}

.menu-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--text);
  padding: 4px 8px;
}

/* Hero */
.hero {
  background: linear-gradient(135deg, #1a8cff 0%, #0066cc 50%, #004499 100%);
  color: var(--white);
  padding: 60px 20px 70px;
  text-align: center;
}

.hero h1 {
  font-size: 2.2rem;
  margin-bottom: 16px;
  line-height: 1.3;
}

.hero-sub {
  font-size: 1.1rem;
  opacity: 0.92;
  max-width: 700px;
  margin: 0 auto 28px;
}

.hero-badges {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px;
  margin-bottom: 32px;
}

.badge {
  background: rgba(255, 255, 255, 0.15);
  padding: 6px 16px;
  border-radius: 20px;
  font-size: 0.85rem;
  backdrop-filter: blur(4px);
}

.btn-group {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 16px;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 32px;
  border-radius: 30px;
  font-weight: 600;
  font-size: 1rem;
  border: none;
  cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s;
}

.btn:hover {
  transform: translateY(-2px);
}

.btn-primary {
  background: var(--white);
  color: var(--primary-dark);
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.15);
}

.btn-outline {
  background: transparent;
  color: var(--white);
  border: 2px solid rgba(255, 255, 255, 0.7);
}

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

/* Sections */
.section {
  padding: 56px 0;
}

.section-alt {
  background: var(--white);
}

.section-title {
  font-size: 1.75rem;
  text-align: center;
  margin-bottom: 12px;
  color: var(--text);
}

.section-desc {
  text-align: center;
  color: var(--text-light);
  max-width: 680px;
  margin: 0 auto 40px;
}

/* Feature Grid */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
}

.feature-card {
  background: var(--white);
  border-radius: var(--radius);
  padding: 28px;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
  transition: transform 0.2s;
}

.feature-card:hover {
  transform: translateY(-4px);
}

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

.feature-card p {
  color: var(--text-light);
  font-size: 0.95rem;
}

.feature-icon {
  width: 48px;
  height: 48px;
  background: linear-gradient(135deg, var(--primary), #00c6ff);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 1.3rem;
  margin-bottom: 16px;
}

/* Screenshot Gallery */
.screenshot-section {
  margin-bottom: 48px;
}

.screenshot-section h3 {
  font-size: 1.3rem;
  margin-bottom: 8px;
  color: var(--primary-dark);
  padding-bottom: 8px;
  border-bottom: 2px solid var(--primary);
  display: inline-block;
}

.screenshot-section p {
  color: var(--text-light);
  margin-bottom: 20px;
}

.screenshot-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 20px;
}

.screenshot-item {
  background: var(--white);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
}

.screenshot-item img {
  width: 100%;
  aspect-ratio: 9/16;
  object-fit: cover;
  object-position: top;
}

.screenshot-caption {
  padding: 12px 16px;
  font-size: 0.9rem;
  color: var(--text-light);
  background: var(--white);
}

/* Content Article */
.article-content {
  background: var(--white);
  border-radius: var(--radius);
  padding: 40px;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
  max-width: 900px;
  margin: 0 auto;
}

.article-content h2 {
  font-size: 1.4rem;
  margin: 32px 0 14px;
  color: var(--primary-dark);
}

.article-content h2:first-child {
  margin-top: 0;
}

.article-content h3 {
  font-size: 1.15rem;
  margin: 24px 0 10px;
  color: var(--text);
}

.article-content p {
  margin-bottom: 16px;
  color: var(--text-light);
}

.article-content ul,
.article-content ol {
  margin: 12px 0 16px 24px;
  color: var(--text-light);
}

.article-content li {
  margin-bottom: 8px;
}

.article-content .inline-img {
  margin: 24px 0;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  max-width: 320px;
}

/* Steps */
.steps {
  counter-reset: step;
  list-style: none;
  margin: 0;
  padding: 0;
}

.steps li {
  counter-increment: step;
  position: relative;
  padding: 20px 20px 20px 60px;
  background: var(--white);
  border-radius: var(--radius);
  margin-bottom: 16px;
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
}

.steps li::before {
  content: counter(step);
  position: absolute;
  left: 16px;
  top: 18px;
  width: 32px;
  height: 32px;
  background: var(--primary);
  color: white;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.9rem;
}

.steps li strong {
  display: block;
  margin-bottom: 6px;
  color: var(--text);
}

/* FAQ */
.faq-list {
  max-width: 800px;
  margin: 0 auto;
}

.faq-item {
  background: var(--white);
  border-radius: var(--radius);
  margin-bottom: 12px;
  border: 1px solid var(--border);
  overflow: hidden;
}

.faq-item summary {
  padding: 18px 24px;
  font-weight: 600;
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

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

.faq-item summary::after {
  content: "+";
  font-size: 1.2rem;
  color: var(--primary);
}

.faq-item[open] summary::after {
  content: "−";
}

.faq-item p {
  padding: 0 24px 18px;
  color: var(--text-light);
}

/* Internal Links */
.internal-links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin: 24px 0;
}

.internal-links a {
  background: var(--bg);
  padding: 8px 16px;
  border-radius: 20px;
  font-size: 0.9rem;
  border: 1px solid var(--border);
}

.internal-links a:hover {
  background: var(--primary);
  color: white;
  border-color: var(--primary);
}

/* Footer */
.site-footer {
  background: #1a1a2e;
  color: rgba(255, 255, 255, 0.75);
  padding: 48px 20px 24px;
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 32px;
  max-width: var(--max-width);
  margin: 0 auto 32px;
}

.footer-grid h4 {
  color: var(--white);
  margin-bottom: 14px;
  font-size: 1rem;
}

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

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

.footer-grid a {
  color: rgba(255, 255, 255, 0.65);
  font-size: 0.9rem;
}

.footer-grid a:hover {
  color: var(--white);
}

.footer-bottom {
  text-align: center;
  padding-top: 24px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  font-size: 0.85rem;
  max-width: var(--max-width);
  margin: 0 auto;
}

/* Error Pages */
.error-page {
  min-height: 70vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 40px 20px;
}

.error-page h1 {
  font-size: 5rem;
  color: var(--primary);
  line-height: 1;
  margin-bottom: 16px;
}

.error-page h2 {
  font-size: 1.5rem;
  margin-bottom: 12px;
}

.error-page p {
  color: var(--text-light);
  margin-bottom: 24px;
}

/* Page Header */
.page-header {
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  color: white;
  padding: 48px 20px;
  text-align: center;
}

.page-header h1 {
  font-size: 2rem;
  margin-bottom: 8px;
}

.page-header p {
  opacity: 0.9;
}

/* Breadcrumb */
.breadcrumb {
  padding: 12px 0;
  font-size: 0.85rem;
  color: var(--text-light);
}

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

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

/* Responsive */
@media (max-width: 768px) {
  .menu-toggle {
    display: block;
  }

  .nav-menu {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--white);
    flex-direction: column;
    padding: 16px 20px;
    gap: 0;
    border-bottom: 1px solid var(--border);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
  }

  .nav-menu.open {
    display: flex;
  }

  .nav-menu li {
    padding: 12px 0;
    border-bottom: 1px solid var(--border);
  }

  .nav-menu li:last-child {
    border-bottom: none;
  }

  .header-inner {
    position: relative;
  }

  .hero h1 {
    font-size: 1.6rem;
  }

  .hero {
    padding: 40px 16px 50px;
  }

  .section {
    padding: 40px 0;
  }

  .article-content {
    padding: 24px 20px;
  }

  .screenshot-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
  }

  .screenshot-caption {
    padding: 8px 10px;
    font-size: 0.8rem;
  }

  .btn {
    padding: 12px 24px;
    font-size: 0.95rem;
  }
}

@media (max-width: 480px) {
  .screenshot-grid {
    grid-template-columns: 1fr 1fr;
  }

  .hero h1 {
    font-size: 1.4rem;
  }

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