body.ui-style-3 {
  font-family: "PingFang SC", "Microsoft YaHei", sans-serif;
}

body.ui-style-3 .header {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

body.ui-style-3 .card {
  transition: all 0.3s ease;
  border: 1px solid #e1e8ed;
}

body.ui-style-3 .card:hover {
  border-color: #3498db;
}

.back-to-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  background: #3498db;
  color: white;
  width: 50px;
  height: 50px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  opacity: 0;
  transition: opacity 0.3s;
  z-index: 999;
}

.back-to-top.show {
  opacity: 1;
}

.back-to-top:hover {
  background: #2980b9;
}

@media (max-width: 768px) {
  .header h1 {
    font-size: 1.5rem;
  }

  .header p {
    font-size: 0.95rem;
  }

  .container {
    padding: 0 0.5rem;
  }

  .card {
    padding: 1rem;
  }

  .grid {
    grid-template-columns: 1fr;
  }
}