body {
  margin: 0;
  font-family: 'PingFang SC', 'Microsoft YaHei', Arial, sans-serif;
  background: #f6f8fa;
  color: #222;
}
header {
  background: #a3cdfd;
  padding: 20px 0;
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.logo {
  font-size: 1.5em;
  font-weight: bold;
  margin-left: 30px;
}
nav a {
  margin: 0 15px;
  color: #222;
  text-decoration: none;
}
.hero {
  text-align: center;
  padding: 60px 20px 30px 20px;
  background: #eaf4ff;
}
.download-btn {
  display: inline-block;
  margin-top: 20px;
  padding: 12px 32px;
  background: #ff4d4f;
  color: #fff;
  border-radius: 30px;
  font-size: 1.1em;
  text-decoration: none;
}
.features, .preview, .contact {
  max-width: 800px;
  margin: 40px auto;
  background: #fff;
  border-radius: 12px;
  padding: 30px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.04);
}
.features ul {
  list-style: disc inside;
  padding-left: 20px;
}
.preview-images {
  display: flex;
  gap: 20px;
  justify-content: center;
  flex-wrap: wrap;
}
.preview-images img {
  width: 200px;
  border-radius: 10px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.08);
}
footer {
  text-align: center;
  padding: 20px 0;
  background: #eaf4ff;
  margin-top: 40px;
  color: #888;
}
@media (max-width: 600px) {
  .features, .preview, .contact {
    padding: 16px;
  }
  .preview-images img {
    width: 100px;
  }
  .logo {
    margin-left: 10px;
  }
  nav a {
    margin: 0 6px;
  }
}