/* ============================================
   通用样式 - 移动优先设计
   ============================================ */

/* CSS重置 */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

/* 基础样式 */
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji";
  font-size: 16px; /* 最小字体16px，符合移动端要求 */
  line-height: 1.5;
  color: #333;
  background-color: #f5f5f5;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* 容器 */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 16px;
}

/* 页面头部 */
.page-header {
  background: #007bff;
  color: white;
  padding: 20px 16px;
  text-align: center;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.page-header h1 {
  font-size: 24px;
  font-weight: 600;
  margin-bottom: 8px;
}

.page-header p {
  font-size: 14px;
  opacity: 0.9;
}

/* 导航链接 */
.nav-link {
  display: inline-block;
  color: white;
  text-decoration: none;
  font-size: 14px;
  padding: 8px 16px;
  margin-top: 12px;
  border: 1px solid rgba(255,255,255,0.5);
  border-radius: 4px;
  min-height: 44px; /* 触摸目标至少44px */
  line-height: 28px;
}

.nav-link:hover {
  background: rgba(255,255,255,0.1);
}

/* 卡片样式（通用） */
.card {
  background: white;
  border-radius: 8px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
  padding: 16px;
  margin: 12px 0;
  cursor: pointer;
  transition: box-shadow 0.2s ease;
  min-height: 44px; /* 触摸目标 */
}

.card:hover {
  box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}

.card:active {
  transform: translateY(1px);
}

/* 加载指示器 */
.loading {
  display: none;
  text-align: center;
  padding: 40px;
  color: #666;
}

.loading.show {
  display: block;
}

.loading-spinner {
  display: inline-block;
  width: 40px;
  height: 40px;
  border: 4px solid #f3f3f3;
  border-top: 4px solid #007bff;
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

/* 错误提示 */
.error {
  display: none;
  background: #fff3cd;
  border: 1px solid #ffc107;
  color: #856404;
  padding: 16px;
  margin: 16px;
  border-radius: 4px;
  text-align: center;
}

.error.show {
  display: block;
}

/* 空状态 */
.empty-state {
  text-align: center;
  padding: 60px 20px;
  color: #999;
}

.empty-state-icon {
  font-size: 48px;
  margin-bottom: 16px;
}

/* 响应式布局 - 平板 */
@media (min-width: 768px) {
  .container {
    padding: 24px;
  }

  .page-header h1 {
    font-size: 28px;
  }

  .card {
    padding: 20px;
  }
}

/* 响应式布局 - 桌面 */
@media (min-width: 1024px) {
  .container {
    padding: 32px;
  }

  .page-header h1 {
    font-size: 32px;
  }
}