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

:root {
  --primary: #00BCD4;
  --primary-dark: #0288D1;
  --accent: #FF9800;
  --bg: #FFFFFF;
  --bg-alt: #E0F7FA;
  --bg-tint: #F0FCFD;
  --text: #1D1D1F;
  --text-secondary: #6E6E73;
  --border: #E5E5EA;
  --shadow: 0 2px 12px rgba(0,0,0,0.06);
  --radius: 12px;
  --max-width: 1100px;
  --nav-height: 64px;
}

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: 1.6;
  padding-top: var(--nav-height);
}

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

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

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

.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  box-shadow: 0 1px 8px rgba(0,188,212,0.08);
  z-index: 1000;
}

.nav .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 32px;
  list-style: none;
}

.nav-links a {
  font-size: 15px;
  color: var(--text-secondary);
  transition: color 0.2s;
  position: relative;
}

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

.nav-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 24px;
  cursor: pointer;
  color: var(--text);
  padding: 4px;
}

.hero {
  padding: 80px 0 60px;
  text-align: center;
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  color: white;
}

.hero h1 {
  font-size: 48px;
  font-weight: 700;
  margin-bottom: 16px;
  letter-spacing: -0.02em;
}

.hero h1 span {
  color: rgba(255,255,255,0.7);
}

.hero p {
  font-size: 20px;
  color: rgba(255,255,255,0.85);
  max-width: 600px;
  margin: 0 auto 32px;
}

.btn {
  display: inline-block;
  padding: 12px 32px;
  border-radius: 8px;
  font-size: 16px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s;
  border: none;
}

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

.btn-primary:hover {
  background: var(--primary-dark);
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(0,188,212,0.3);
}

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

.btn-white:hover {
  background: var(--bg-alt);
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}

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

.btn-accent:hover {
  background: #E68900;
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(255,152,0,0.3);
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
}

.card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px 24px;
  transition: all 0.3s;
  border-top: 3px solid var(--primary);
}

.card.card-accent {
  border-top-color: var(--accent);
}

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

.card-icon {
  font-size: 32px;
  margin-bottom: 16px;
}

.card h3 {
  font-size: 18px;
  margin-bottom: 8px;
}

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

.section-title {
  text-align: center;
  margin-bottom: 48px;
}

.section-title h2 {
  font-size: 32px;
  margin-bottom: 12px;
}

.section-title p {
  color: var(--text-secondary);
  font-size: 16px;
  max-width: 500px;
  margin: 0 auto;
}

.section {
  padding: 80px 0;
}

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

.footer {
  background: var(--text);
  color: rgba(255,255,255,0.7);
  padding: 40px 0;
  text-align: center;
  font-size: 14px;
}

.footer a {
  color: rgba(255,255,255,0.9);
}

.footer .footer-links {
  display: flex;
  justify-content: center;
  gap: 24px;
  margin-bottom: 16px;
  flex-wrap: wrap;
}

.footer .footer-links a:hover {
  color: white;
}

.footer .icp {
  color: rgba(255,255,255,0.5);
  font-size: 12px;
}

.product-showcase {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
}

.product-screenshot {
  background: var(--bg-tint);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  aspect-ratio: 16/9;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-secondary);
  font-size: 14px;
}

.product-info h2 {
  font-size: 28px;
  margin-bottom: 8px;
}

.product-info .tag {
  display: inline-block;
  padding: 4px 12px;
  background: var(--primary);
  color: white;
  border-radius: 20px;
  font-size: 13px;
  margin-bottom: 16px;
}

.product-info p {
  color: var(--text-secondary);
  margin-bottom: 24px;
  line-height: 1.8;
}

.product-features {
  list-style: none;
  margin-bottom: 24px;
}

.product-features li {
  padding: 8px 0;
  padding-left: 24px;
  position: relative;
  color: var(--text-secondary);
}

.product-features li::before {
  content: "\2713";
  position: absolute;
  left: 0;
  color: var(--primary);
  font-weight: 700;
}

.about-intro {
  max-width: 700px;
  margin: 0 auto 48px;
  text-align: center;
  font-size: 16px;
  color: var(--text-secondary);
  line-height: 1.8;
}

.contact-bar {
  text-align: center;
  padding: 32px;
  background: var(--bg-tint);
  border-radius: var(--radius);
}

.contact-bar p {
  color: var(--text-secondary);
  margin-bottom: 8px;
}

.contact-bar .email {
  color: var(--primary);
  font-size: 18px;
  font-weight: 500;
}

.page-404 {
  text-align: center;
  padding: 100px 24px;
}

.page-404 h1 {
  font-size: 80px;
  color: var(--primary);
  margin-bottom: 16px;
}

.page-404 p {
  color: var(--text-secondary);
  margin-bottom: 32px;
}

@media (max-width: 768px) {
  .nav-links {
    display: none;
    position: absolute;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background: var(--bg);
    flex-direction: column;
    padding: 16px 24px;
    gap: 16px;
    border-bottom: 1px solid var(--border);
  }

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

  .nav-toggle {
    display: block;
  }

  .hero h1 {
    font-size: 32px;
  }

  .hero p {
    font-size: 16px;
  }

  .section-title h2 {
    font-size: 26px;
  }

  .product-showcase {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .section {
    padding: 48px 0;
  }

  .hero {
    padding: 48px 0 32px;
  }
}