/* 全局样式重置 */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  line-height: 1.6;
  color: #333;
  background-color: #f5f5f5;
}

/* 容器样式 */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

/* 导航栏样式 */
.navbar {
  background-color: #343a40;
  color: white;
  padding: 1rem 0;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
}

.navbar .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.navbar-brand {
  font-size: 1.5rem;
  font-weight: bold;
  color: white;
  text-decoration: none;
}

.navbar-nav {
  display: flex;
  list-style: none;
}

.nav-item {
  margin-left: 1rem;
}

.nav-link {
  color: white;
  text-decoration: none;
  font-size: 1rem;
  padding: 0.5rem 1rem;
  border-radius: 4px;
  transition: background-color 0.3s ease;
}

.nav-link:hover {
  background-color: #495057;
}

/* 侧边栏样式 */
.sidebar {
  background-color: #343a40;
  color: white;
  width: 250px;
  height: 100vh;
  position: fixed;
  top: 0;
  left: 0;
  padding-top: 70px;
  overflow-y: auto;
}

.sidebar-menu {
  list-style: none;
}

.sidebar-item {
  margin-bottom: 0.5rem;
}

.sidebar-link {
  color: white;
  text-decoration: none;
  display: block;
  padding: 0.75rem 1.5rem;
  transition: background-color 0.3s ease;
}

.sidebar-link:hover {
  background-color: #495057;
}

.sidebar-link.active {
  background-color: #007bff;
}

/* 主内容区样式 */
.main-content {
  margin-left: 250px;
  margin-top: 70px;
  padding: 2rem;
}

/* 卡片样式 */
.card {
  background-color: white;
  border-radius: 8px;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
  padding: 1.5rem;
  margin-bottom: 1.5rem;
}

.card-header {
  border-bottom: 1px solid #e9ecef;
  padding-bottom: 1rem;
  margin-bottom: 1rem;
}

.card-title {
  font-size: 1.25rem;
  font-weight: bold;
  margin: 0;
}

/* 按钮样式 */
.btn {
  display: inline-block;
  padding: 0.5rem 1rem;
  border: none;
  border-radius: 4px;
  font-size: 0.875rem;
  font-weight: 500;
  text-align: center;
  text-decoration: none;
  cursor: pointer;
  transition: all 0.3s ease;
}

.btn-primary {
  background-color: #007bff;
  color: white;
}

.btn-primary:hover {
  background-color: #0056b3;
}

.btn-success {
  background-color: #28a745;
  color: white;
}

.btn-success:hover {
  background-color: #1e7e34;
}

.btn-danger {
  background-color: #dc3545;
  color: white;
}

.btn-danger:hover {
  background-color: #c82333;
}

.btn-warning {
  background-color: #ffc107;
  color: #212529;
}

.btn-warning:hover {
  background-color: #e0a800;
}

/* 表单样式 */
.form-group {
  margin-bottom: 1rem;
}

.form-label {
  display: block;
  font-weight: 500;
  margin-bottom: 0.5rem;
  color: #495057;
}

.form-control {
  display: block;
  width: 100%;
  padding: 0.5rem 0.75rem;
  font-size: 0.875rem;
  line-height: 1.5;
  color: #495057;
  background-color: white;
  background-clip: padding-box;
  border: 1px solid #ced4da;
  border-radius: 4px;
  transition: border-color 0.15s ease-in-out, box-shadow 0.15s ease-in-out;
}

.form-control:focus {
  border-color: #80bdff;
  outline: 0;
  box-shadow: 0 0 0 0.2rem rgba(0, 123, 255, 0.25);
}

textarea.form-control {
  resize: vertical;
  min-height: 150px;
}

/* 表格样式 */
.table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: 1rem;
}

.table th,
.table td {
  padding: 0.75rem;
  text-align: left;
  border-bottom: 1px solid #e9ecef;
}

.table th {
  background-color: #f8f9fa;
  font-weight: 600;
  color: #495057;
}

.table tr:hover {
  background-color: #f8f9fa;
}

/* 分页样式 */
.pagination {
  display: flex;
  list-style: none;
  padding: 0;
  margin: 1rem 0;
}

.pagination-item {
  margin-right: 0.5rem;
}

.pagination-link {
  display: inline-block;
  padding: 0.5rem 0.75rem;
  background-color: white;
  border: 1px solid #dee2e6;
  border-radius: 4px;
  color: #007bff;
  text-decoration: none;
  transition: all 0.3s ease;
}

.pagination-link:hover {
  background-color: #e9ecef;
}

.pagination-link.active {
  background-color: #007bff;
  color: white;
  border-color: #007bff;
}

/* 登录页面样式 */
.login-container {
  max-width: 400px;
  margin: 100px auto;
  padding: 2rem;
  background-color: white;
  border-radius: 8px;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.login-title {
  font-size: 1.5rem;
  font-weight: bold;
  text-align: center;
  margin-bottom: 1.5rem;
  color: #333;
}

.error-message {
  color: #dc3545;
  background-color: #f8d7da;
  border: 1px solid #f5c6cb;
  padding: 0.75rem;
  border-radius: 4px;
  margin-bottom: 1rem;
}

/* 统计卡片样式 */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1.5rem;
  margin-bottom: 2rem;
}

.stat-card {
  background-color: white;
  border-radius: 8px;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
  padding: 1.5rem;
  text-align: center;
}

.stat-number {
  font-size: 2rem;
  font-weight: bold;
  color: #007bff;
  margin-bottom: 0.5rem;
}

.stat-label {
  font-size: 0.875rem;
  color: #6c757d;
}

/* 响应式设计 */
@media (max-width: 768px) {
  .sidebar {
    width: 100%;
    height: auto;
    position: static;
    padding-top: 1rem;
  }

  .main-content {
    margin-left: 0;
    margin-top: 0;
    padding: 1rem;
  }

  .navbar .container {
    flex-direction: column;
  }

  .navbar-nav {
    margin-top: 1rem;
  }

  .nav-item {
    margin: 0 0.5rem;
  }
}