/* 小蓝APP官网 - xlm.quest */
:root {
  --primary: #1a73e8;
  --primary-dark: #1557b0;
  --accent: #00bcd4;
  --text: #333;
  --text-light: #666;
  --bg: #f8fafc;
  --white: #fff;
  --border: #e2e8f0;
  --shadow: 0 4px 20px rgba(0,0,0,.08);
  --radius: 12px;
  --max-width: 1200px;
}

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

html { scroll-behavior: smooth; font-size: 16px; }

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: 1.7;
}

a { color: var(--primary); text-decoration: none; transition: color .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);
  box-shadow: 0 2px 10px rgba(0,0,0,.06);
  position: sticky;
  top: 0;
  z-index: 1000;
}

.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;
  color: var(--text);
  font-weight: 700;
  font-size: 1.2rem;
}

.logo-link img { width: 40px; height: 40px; border-radius: 8px; }

.main-nav { display: flex; gap: 28px; align-items: center; }
.main-nav a { color: var(--text); font-size: .95rem; font-weight: 500; }
.main-nav a:hover, .main-nav a.active { color: var(--primary); }

.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text);
  margin: 5px 0;
  transition: .3s;
}

/* Hero */
.hero {
  background: linear-gradient(135deg, #1a73e8 0%, #00bcd4 100%);
  color: var(--white);
  padding: 60px 20px 80px;
  text-align: center;
}

.hero h1 { font-size: 2.2rem; margin-bottom: 16px; line-height: 1.3; }
.hero p { font-size: 1.1rem; opacity: .92; max-width: 700px; margin: 0 auto 30px; }

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

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 32px;
  border-radius: 50px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: transform .2s, box-shadow .2s;
}

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

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

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

/* Sections */
section { padding: 60px 0; }

.section-title {
  text-align: center;
  font-size: 1.8rem;
  margin-bottom: 12px;
  color: var(--text);
}

.section-subtitle {
  text-align: center;
  color: var(--text-light);
  margin-bottom: 40px;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

/* Feature Grid */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.feature-card {
  background: var(--white);
  border-radius: var(--radius);
  padding: 28px;
  box-shadow: var(--shadow);
  transition: transform .2s;
}

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

.feature-card h3 { font-size: 1.15rem; margin-bottom: 10px; color: var(--primary); }
.feature-card p { color: var(--text-light); font-size: .95rem; }

/* Screenshot Gallery */
.screenshot-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

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

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

.screenshot-item figcaption {
  padding: 12px;
  font-size: .85rem;
  color: var(--text-light);
  text-align: center;
}

/* Content Article */
.content-article {
  background: var(--white);
  border-radius: var(--radius);
  padding: 40px;
  box-shadow: var(--shadow);
  margin-bottom: 30px;
}

.content-article h2 {
  font-size: 1.5rem;
  margin: 32px 0 16px;
  color: var(--primary);
  padding-bottom: 8px;
  border-bottom: 2px solid var(--border);
}

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

.content-article h3 { font-size: 1.2rem; margin: 24px 0 12px; color: var(--text); }

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

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

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

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

/* Two Column Layout */
.two-col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
  align-items: center;
}

.two-col.reverse { direction: rtl; }
.two-col.reverse > * { direction: ltr; }

/* Steps */
.steps { counter-reset: step; }

.step-item {
  display: flex;
  gap: 20px;
  margin-bottom: 24px;
  background: var(--white);
  padding: 24px;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.step-item::before {
  counter-increment: step;
  content: counter(step);
  flex-shrink: 0;
  width: 44px;
  height: 44px;
  background: var(--primary);
  color: var(--white);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 1.1rem;
}

.step-item h3 { margin-bottom: 8px; }
.step-item p { color: var(--text-light); font-size: .95rem; }

/* FAQ */
.faq-item {
  background: var(--white);
  border-radius: var(--radius);
  margin-bottom: 12px;
  box-shadow: var(--shadow);
  overflow: hidden;
}

.faq-item summary {
  padding: 18px 24px;
  cursor: pointer;
  font-weight: 600;
  list-style: none;
}

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

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

/* Page Header */
.page-header {
  background: linear-gradient(135deg, #1a73e8, #00bcd4);
  color: var(--white);
  padding: 50px 20px;
  text-align: center;
}

.page-header h1 { font-size: 2rem; margin-bottom: 8px; }
.page-header p { opacity: .9; }

/* Legal Page */
.legal-content {
  background: var(--white);
  border-radius: var(--radius);
  padding: 40px;
  box-shadow: var(--shadow);
  margin: -30px auto 60px;
  max-width: 900px;
  position: relative;
}

.legal-content h2 { font-size: 1.3rem; margin: 28px 0 12px; color: var(--primary); }
.legal-content h2:first-child { margin-top: 0; }
.legal-content p, .legal-content li { color: var(--text-light); margin-bottom: 12px; }
.legal-content ul, .legal-content ol { margin-left: 24px; margin-bottom: 16px; }

/* 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: 6rem; color: var(--primary); line-height: 1; }
.error-page h2 { font-size: 1.5rem; margin: 16px 0; }
.error-page p { color: var(--text-light); margin-bottom: 24px; }

/* Footer */
.site-footer {
  background: #1e293b;
  color: #94a3b8;
  padding: 50px 20px 30px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  max-width: var(--max-width);
  margin: 0 auto 30px;
}

.footer-brand img { width: 48px; border-radius: 8px; margin-bottom: 12px; }
.footer-brand p { font-size: .9rem; line-height: 1.6; }

.footer-col h4 { color: var(--white); margin-bottom: 16px; font-size: 1rem; }
.footer-col a { display: block; color: #94a3b8; margin-bottom: 10px; font-size: .9rem; }
.footer-col a:hover { color: var(--white); }

.footer-bottom {
  border-top: 1px solid #334155;
  padding-top: 20px;
  text-align: center;
  font-size: .85rem;
  max-width: var(--max-width);
  margin: 0 auto;
}

/* Breadcrumb */
.breadcrumb {
  padding: 16px 0;
  font-size: .9rem;
  color: var(--text-light);
}

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

/* TOC */
.toc {
  background: var(--white);
  border-radius: var(--radius);
  padding: 24px;
  margin-bottom: 30px;
  box-shadow: var(--shadow);
}

.toc h3 { margin-bottom: 12px; font-size: 1rem; }
.toc ol { margin-left: 20px; }
.toc li { margin-bottom: 6px; font-size: .9rem; }

/* Responsive */
@media (max-width: 992px) {
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
  .screenshot-grid { grid-template-columns: repeat(3, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .two-col { grid-template-columns: 1fr; }
}

@media (max-width: 768px) {
  .nav-toggle { display: block; }

  .main-nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--white);
    flex-direction: column;
    padding: 20px;
    box-shadow: var(--shadow);
    gap: 16px;
  }

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

  .hero h1 { font-size: 1.6rem; }
  .hero { padding: 40px 20px 60px; }

  .feature-grid { grid-template-columns: 1fr; }
  .screenshot-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr; }

  .content-article, .legal-content { padding: 24px; }
  section { padding: 40px 0; }
}

@media (max-width: 480px) {
  .screenshot-grid { grid-template-columns: 1fr; }
  .btn { width: 100%; justify-content: center; }
}