/* ========== CSS 变量 ========== */
:root {
  --primary: #1890ff;
  --primary-dark: #0077cc;
  --primary-light: #e6f7ff;
  --gradient: linear-gradient(135deg, #1890ff 0%, #00b4d8 100%);
  --bg: #f5f7fa;
  --text: #333;
  --text-light: #666;
  --text-lighter: #999;
  --border: #e8e8e8;
  --shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
  --shadow-hover: 0 8px 24px rgba(0, 0, 0, 0.12);
  --radius: 12px;
  --container-width: 1200px;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  color: var(--text);
  background: #fff;
  line-height: 1.6;
  overflow-x: hidden;
}

a { text-decoration: none; color: inherit; }
ul { list-style: none; }

/* ========== Container ========== */
.container {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* ========== Navbar ========== */
.navbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: 64px;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.06);
  z-index: 1000;
  transition: box-shadow 0.3s;
}
.navbar.scrolled { box-shadow: 0 2px 12px rgba(0, 0, 0, 0.1); }
.navbar .container {
  display: flex; align-items: center; justify-content: space-between; height: 100%;
}
.navbar-logo {
  display: flex; align-items: center; gap: 8px;
  font-size: 18px; font-weight: 700; color: var(--primary);
}
.navbar-logo svg { width: 24px; height: 24px; }
.navbar-links { display: flex; align-items: center; gap: 32px; }
.navbar-links a { font-size: 15px; color: var(--text-light); transition: color 0.2s; }
.navbar-links a:hover, .navbar-links a.active { color: var(--primary); }
.navbar-actions { display: flex; align-items: center; gap: 16px; }

/* ========== Buttons ========== */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  padding: 10px 24px; border-radius: 8px; font-size: 15px; font-weight: 500;
  border: none; cursor: pointer; transition: all 0.3s;
}
.btn-primary { background: var(--gradient); color: #fff; }
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 4px 12px rgba(24, 144, 255, 0.4); }
.btn-outline { background: transparent; color: var(--primary); border: 2px solid var(--primary); }
.btn-outline:hover { background: var(--primary); color: #fff; }
.btn-white { background: #fff; color: var(--primary); }
.btn-white:hover { transform: translateY(-2px); box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15); }
.btn-lg { padding: 14px 32px; font-size: 16px; }

/* ========== Mobile Menu ========== */
.menu-toggle { display: none; flex-direction: column; gap: 4px; cursor: pointer; padding: 8px; }
.menu-toggle span { width: 24px; height: 2px; background: var(--text); transition: all 0.3s; }

/* ========== Hero ========== */
.hero {
  min-height: 100vh; display: flex; align-items: center; justify-content: center;
  text-align: center; background: var(--gradient); color: #fff;
  position: relative; overflow: hidden; padding-top: 64px;
}
.hero::before, .hero::after { content: ''; position: absolute; border-radius: 50%; background: rgba(255, 255, 255, 0.08); }
.hero::before { width: 600px; height: 600px; top: -200px; right: -100px; }
.hero::after { width: 400px; height: 400px; bottom: -100px; left: -100px; }
.hero-content { position: relative; z-index: 1; max-width: 800px; padding: 0 24px; }
.hero h1 { font-size: 56px; font-weight: 700; margin-bottom: 16px; letter-spacing: 2px; }
.hero .subtitle { font-size: 24px; font-weight: 300; margin-bottom: 12px; opacity: 0.95; }
.hero .description { font-size: 16px; opacity: 0.8; margin-bottom: 40px; }
.hero-buttons { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }
.scroll-hint { position: absolute; bottom: 30px; left: 50%; transform: translateX(-50%); z-index: 1; animation: bounce 2s infinite; }
.scroll-hint svg { width: 24px; height: 24px; opacity: 0.7; }
@keyframes bounce { 0%, 100% { transform: translateX(-50%) translateY(0); } 50% { transform: translateX(-50%) translateY(10px); } }

/* ========== Section ========== */
.section { padding: 80px 0; }
.section-gray { background: var(--bg); }
.section-title { text-align: center; font-size: 36px; font-weight: 700; margin-bottom: 12px; }
.section-subtitle { text-align: center; font-size: 16px; color: var(--text-light); margin-bottom: 48px; }

/* ========== Intro ========== */
.intro { text-align: center; max-width: 800px; margin: 0 auto; font-size: 18px; color: var(--text-light); line-height: 1.8; }

/* ========== Features ========== */
.features-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.feature-card {
  background: #fff; border-radius: var(--radius); padding: 32px 24px;
  box-shadow: var(--shadow); transition: all 0.3s; text-align: center;
}
.feature-card:hover { transform: translateY(-8px); box-shadow: var(--shadow-hover); }
.feature-icon {
  width: 56px; height: 56px; margin: 0 auto 16px;
  display: flex; align-items: center; justify-content: center;
  border-radius: 12px; background: var(--primary-light);
}
.feature-icon svg { width: 28px; height: 28px; color: var(--primary); }
.feature-card h3 { font-size: 16px; font-weight: 600; margin-bottom: 8px; }
.feature-card p { font-size: 14px; color: var(--text-light); line-height: 1.6; }

/* ========== Screenshots ========== */
.screenshots-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 32px; }
.screenshot-card {
  background: #fff; border-radius: var(--radius);
  box-shadow: var(--shadow); overflow: hidden; transition: all 0.3s;
}
.screenshot-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-hover); }
.screenshot-card img { width: 100%; height: auto; display: block; border-bottom: 1px solid var(--border); }
.screenshot-card h3 { font-size: 18px; font-weight: 600; padding: 20px 24px 8px; }
.screenshot-card p { font-size: 14px; color: var(--text-light); padding: 0 24px 24px; line-height: 1.6; }

/* ========== Advantages ========== */
.advantages-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.advantage-card {
  background: #fff; border-radius: var(--radius); padding: 32px;
  box-shadow: var(--shadow); transition: all 0.3s; display: flex; gap: 16px;
}
.advantage-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-hover); }
.advantage-number { font-size: 36px; font-weight: 700; color: var(--primary); opacity: 0.2; line-height: 1; flex-shrink: 0; }
.advantage-card h3 { font-size: 16px; font-weight: 600; margin-bottom: 8px; }
.advantage-card p { font-size: 14px; color: var(--text-light); line-height: 1.6; }

/* ========== Use Cases ========== */
.use-cases-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.use-case-card {
  background: #fff; border-radius: var(--radius); padding: 32px 24px;
  box-shadow: var(--shadow); transition: all 0.3s; border-top: 4px solid var(--primary);
}
.use-case-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-hover); }
.use-case-card h3 { font-size: 18px; font-weight: 600; margin-bottom: 8px; }
.use-case-card p { font-size: 14px; color: var(--text-light); line-height: 1.6; }

/* ========== CTA ========== */
.cta-section { background: var(--gradient); text-align: center; padding: 80px 0; color: #fff; }
.cta-section h2 { font-size: 32px; font-weight: 700; margin-bottom: 24px; }

/* ========== Footer ========== */
.footer { background: #1a1a2e; color: #999; padding: 40px 0; text-align: center; }
.footer-links { display: flex; justify-content: center; gap: 24px; margin-bottom: 16px; }
.footer-links a { font-size: 14px; color: #999; transition: color 0.2s; }
.footer-links a:hover { color: #fff; }
.footer-copyright { font-size: 14px; color: #666; }

/* ========== Code Block ========== */
.code-block { position: relative; background: #1e1e1e; border-radius: 8px; margin: 16px 0; overflow: hidden; }
.code-block pre { padding: 16px 20px; overflow-x: auto; }
.code-block code { font-family: 'SF Mono', Monaco, Menlo, Consolas, monospace; font-size: 14px; color: #d4d4d4; line-height: 1.6; }
.copy-btn {
  position: absolute; top: 8px; right: 8px; padding: 4px 12px;
  background: rgba(255, 255, 255, 0.1); color: #999; border: none;
  border-radius: 4px; font-size: 12px; cursor: pointer; transition: all 0.2s;
}
.copy-btn:hover { background: rgba(255, 255, 255, 0.2); color: #fff; }
.copy-btn.copied { color: #4ec9b0; }

/* ========== Table ========== */
.table-wrapper { overflow-x: auto; margin: 16px 0; }
table { width: 100%; border-collapse: collapse; font-size: 14px; background: #fff; border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow); }
th { background: var(--primary-light); color: var(--primary); font-weight: 600; padding: 12px 16px; text-align: left; white-space: nowrap; }
td { padding: 12px 16px; border-top: 1px solid var(--border); }
tr:nth-child(even) td { background: #fafafa; }
td code { font-family: 'SF Mono', Monaco, Menlo, Consolas, monospace; font-size: 13px; color: var(--primary); background: var(--primary-light); padding: 2px 6px; border-radius: 4px; }

/* ========== FAQ ========== */
.faq-item { background: #fff; border-radius: var(--radius); margin-bottom: 12px; box-shadow: var(--shadow); overflow: hidden; }
.faq-question { padding: 20px 24px; display: flex; align-items: center; justify-content: space-between; cursor: pointer; font-weight: 500; font-size: 15px; }
.faq-question svg { width: 20px; height: 20px; color: var(--text-lighter); transition: transform 0.3s; flex-shrink: 0; }
.faq-item.active .faq-question svg { transform: rotate(180deg); }
.faq-answer { max-height: 0; overflow: hidden; transition: max-height 0.3s ease; }
.faq-item.active .faq-answer { max-height: 400px; }
.faq-answer-inner { padding: 0 24px 20px; color: var(--text-light); font-size: 14px; line-height: 1.8; }

/* ========== Install Page ========== */
.page-header { background: var(--gradient); color: #fff; text-align: center; padding: 120px 0 60px; }
.page-header h1 { font-size: 36px; font-weight: 700; margin-bottom: 12px; }
.page-header p { font-size: 16px; opacity: 0.9; }

.install-layout { display: flex; gap: 40px; max-width: var(--container-width); margin: 0 auto; padding: 0 24px; }
.step-nav { flex-shrink: 0; width: 200px; position: sticky; top: 88px; align-self: flex-start; }
.step-nav ul { list-style: none; }
.step-nav li { margin-bottom: 8px; }
.step-nav a { display: flex; align-items: center; gap: 8px; padding: 10px 16px; border-radius: 8px; font-size: 14px; color: var(--text-light); transition: all 0.2s; }
.step-nav a:hover, .step-nav a.active { background: var(--primary-light); color: var(--primary); }
.step-nav .step-number { width: 24px; height: 24px; border-radius: 50%; background: var(--border); color: var(--text-light); display: flex; align-items: center; justify-content: center; font-size: 12px; font-weight: 600; flex-shrink: 0; }
.step-nav a.active .step-number { background: var(--primary); color: #fff; }
.step-content { flex: 1; min-width: 0; }
.step-section { margin-bottom: 48px; }
.step-section h2 { font-size: 24px; font-weight: 700; margin-bottom: 16px; display: flex; align-items: center; gap: 12px; }
.step-section h2 .step-badge { display: inline-flex; align-items: center; justify-content: center; width: 32px; height: 32px; border-radius: 50%; background: var(--primary); color: #fff; font-size: 14px; }
.step-section h3 { font-size: 18px; font-weight: 600; margin: 24px 0 12px; }
.step-section p { color: var(--text-light); margin-bottom: 12px; line-height: 1.8; }

.req-cards { display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px; margin: 24px 0; }
.req-card { background: #fff; border-radius: var(--radius); padding: 24px; box-shadow: var(--shadow); display: flex; align-items: center; gap: 16px; }
.req-card svg { width: 40px; height: 40px; color: var(--primary); flex-shrink: 0; }
.req-card h4 { font-size: 16px; font-weight: 600; margin-bottom: 4px; }
.req-card p { font-size: 14px; color: var(--text-light); margin: 0; }

/* ========== Scroll Animation ========== */
.fade-in { opacity: 0; transform: translateY(30px); transition: opacity 0.6s ease, transform 0.6s ease; }
.fade-in.visible { opacity: 1; transform: translateY(0); }

/* ========== Notice / Tip ========== */
.notice {
  background: var(--primary-light);
  border-left: 4px solid var(--primary);
  padding: 12px 16px;
  border-radius: 0 8px 8px 0;
  margin: 16px 0;
  font-size: 14px;
  color: var(--text-light);
  line-height: 1.8;
}
.notice strong { color: var(--primary); }

/* ========== Architecture Diagram ========== */
.arch-diagram {
  background: #f8f9fa;
  border: 2px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  margin: 16px 0;
  font-family: 'SF Mono', Monaco, Menlo, Consolas, monospace;
  font-size: 13px;
  line-height: 1.8;
  overflow-x: auto;
  white-space: pre;
  color: var(--text-light);
}

/* ========== Checklist ========== */
.checklist {
  background: #fff;
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: var(--shadow);
  margin: 16px 0;
}
.checklist h3 { margin-bottom: 16px; font-size: 18px; }
.checklist ul { list-style: none; }
.checklist li { padding: 8px 0; font-size: 14px; color: var(--text-light); display: flex; align-items: center; gap: 8px; }
.checklist li::before { content: '\2610'; font-size: 18px; color: var(--primary); }

/* ========== Step sub-list ========== */
.step-list { padding-left: 0; list-style: none; margin: 12px 0; }
.step-list li { padding: 6px 0 6px 24px; position: relative; color: var(--text-light); font-size: 14px; line-height: 1.8; }
.step-list li::before { content: ''; position: absolute; left: 0; top: 16px; width: 8px; height: 8px; border-radius: 50%; background: var(--primary); opacity: 0.5; }

/* ========== Responsive ========== */
@media (max-width: 1024px) {
  .features-grid { grid-template-columns: repeat(2, 1fr); }
  .advantages-grid, .use-cases-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 768px) {
  .navbar-links {
    display: none; position: absolute; top: 64px; left: 0; right: 0;
    background: #fff; flex-direction: column; padding: 16px 24px; gap: 16px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
  }
  .navbar-links.show { display: flex; }
  .menu-toggle { display: flex; }
  .hero h1 { font-size: 36px; }
  .hero .subtitle { font-size: 18px; }
  .section-title { font-size: 28px; }
  .features-grid, .advantages-grid, .use-cases-grid, .req-cards, .screenshots-grid { grid-template-columns: 1fr; }
  .install-layout { flex-direction: column; }
  .step-nav { width: 100%; position: static; }
  .step-nav ul { display: flex; overflow-x: auto; gap: 8px; }
  .step-nav li { flex-shrink: 0; }
  .hero-buttons { flex-direction: column; }
  .hero-buttons .btn { width: 100%; }
}