/* ===== 全局 ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans SC", sans-serif;
  color: #333;
  background: #fff;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}
a { text-decoration: none; color: inherit; }

/* ===== 导航栏 ===== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(255,255,255,0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(0,0,0,0.08);
}
.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
  height: 60px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.nav-logo {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 20px;
  font-weight: 700;
  color: #2196F3;
}
.logo-icon { width: 28px; height: 28px; }
.nav-links { display: flex; gap: 32px; }
.nav-links a {
  font-size: 15px;
  font-weight: 500;
  color: #555;
  transition: color 0.2s;
}
.nav-links a:hover { color: #2196F3; }

/* ===== 主横幅 ===== */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  overflow: hidden;
  padding: 120px 24px 80px;
}
.hero-bg {
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, #e3f2fd 0%, #bbdefb 25%, #e8f5e9 60%, #fff3e0 100%);
  z-index: 0;
}
.hero-bg::after {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle at 30% 50%, rgba(33,150,243,0.08) 0%, transparent 50%),
              radial-gradient(circle at 70% 50%, rgba(76,175,80,0.06) 0%, transparent 50%);
  animation: heroFloat 20s ease-in-out infinite;
}
@keyframes heroFloat {
  0%, 100% { transform: translate(0, 0) rotate(0deg); }
  33% { transform: translate(2%, -1%) rotate(1deg); }
  66% { transform: translate(-1%, 1%) rotate(-1deg); }
}
.hero-content {
  position: relative;
  z-index: 1;
  max-width: 720px;
}
.hero-title {
  font-size: 56px;
  font-weight: 800;
  color: #1a237e;
  line-height: 1.2;
}
.hero-subtitle {
  display: block;
  font-size: 24px;
  font-weight: 500;
  color: #2196F3;
  margin-top: 8px;
}
.hero-desc {
  font-size: 18px;
  color: #555;
  margin-top: 24px;
  line-height: 1.8;
}
.hero-buttons {
  margin-top: 40px;
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 36px;
  border-radius: 50px;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s;
  border: none;
}
.btn-primary {
  background: linear-gradient(135deg, #2196F3, #1976D2);
  color: #fff;
  box-shadow: 0 4px 20px rgba(33,150,243,0.35);
}
.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(33,150,243,0.45);
}
.btn-outline {
  background: transparent;
  color: #2196F3;
  border: 2px solid #2196F3;
}
.btn-outline:hover {
  background: #2196F3;
  color: #fff;
}
.hero-stats {
  display: flex;
  justify-content: center;
  gap: 48px;
  margin-top: 56px;
}
.stat-item { text-align: center; }
.stat-num {
  display: block;
  font-size: 28px;
  font-weight: 700;
  color: #1a237e;
}
.stat-label {
  font-size: 14px;
  color: #888;
  margin-top: 4px;
}

/* ===== 功能特性 ===== */
.features {
  padding: 100px 24px;
  background: #fafafa;
}
.container {
  max-width: 1100px;
  margin: 0 auto;
}
.section-title {
  text-align: center;
  font-size: 36px;
  font-weight: 700;
  color: #1a237e;
}
.section-desc {
  text-align: center;
  font-size: 16px;
  color: #777;
  margin-top: 12px;
}
.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-top: 48px;
}
.feature-card {
  background: #fff;
  border-radius: 20px;
  padding: 36px 28px;
  text-align: center;
  transition: all 0.3s;
  box-shadow: 0 2px 12px rgba(0,0,0,0.06);
}
.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 32px rgba(0,0,0,0.1);
}
.feature-icon {
  width: 60px;
  height: 60px;
  margin: 0 auto 20px;
  border-radius: 16px;
  background: linear-gradient(135deg, #e3f2fd, #bbdefb);
}
.feature-card h3 {
  font-size: 18px;
  font-weight: 600;
  color: #333;
  margin-bottom: 8px;
}
.feature-card p {
  font-size: 14px;
  color: #777;
  line-height: 1.7;
}

/* ===== 下载区域 ===== */
.download {
  padding: 100px 24px;
  background: linear-gradient(180deg, #fff 0%, #e3f2fd 100%);
}
.download-cards {
  display: flex;
  justify-content: center;
  gap: 32px;
  margin-top: 48px;
  flex-wrap: wrap;
}
.download-card {
  background: #fff;
  border-radius: 24px;
  padding: 48px 40px;
  text-align: center;
  width: 340px;
  box-shadow: 0 4px 24px rgba(0,0,0,0.08);
  transition: all 0.3s;
}
.download-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 40px rgba(0,0,0,0.12);
}
.card-icon {
  width: 72px;
  height: 72px;
  margin: 0 auto 24px;
  color: #2196F3;
  background: linear-gradient(135deg, #e3f2fd, #bbdefb);
  border-radius: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
}
.card-icon svg { width: 36px; height: 36px; }
.download-card h3 {
  font-size: 20px;
  font-weight: 700;
  color: #333;
}
.card-version {
  font-size: 28px;
  font-weight: 700;
  color: #2196F3;
  margin: 8px 0 4px;
}
.card-size {
  font-size: 14px;
  color: #999;
  margin-bottom: 24px;
}
.btn-download {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 32px;
  border-radius: 50px;
  font-size: 16px;
  font-weight: 600;
  background: linear-gradient(135deg, #2196F3, #1976D2);
  color: #fff;
  box-shadow: 0 4px 16px rgba(33,150,243,0.3);
  transition: all 0.3s;
}
.btn-download:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 28px rgba(33,150,243,0.4);
}
.download-note {
  text-align: center;
  margin-top: 32px;
  font-size: 14px;
  color: #aaa;
}

/* ===== 页脚 ===== */
.footer {
  padding: 32px 24px;
  text-align: center;
  background: #1a237e;
  color: rgba(255,255,255,0.7);
  font-size: 14px;
}
.footer-beian a:hover { color: rgba(255,255,255,0.9) !important; }

/* ===== 响应式 ===== */
@media (max-width: 768px) {
  .hero-title { font-size: 36px; }
  .hero-subtitle { font-size: 18px; }
  .hero-desc { font-size: 15px; }
  .hero-stats { gap: 24px; }
  .feature-grid { grid-template-columns: 1fr 1fr; }
  .download-card { width: 100%; max-width: 340px; }
  .section-title { font-size: 28px; }
}
@media (max-width: 480px) {
  .feature-grid { grid-template-columns: 1fr; }
  .nav-links { gap: 16px; }
  .nav-links a { font-size: 14px; }
}