/* 自定义样式 */
:root {
  --primary-color: #3498db;
  --secondary-color: #2ecc71;
  --dark-color: #2c3e50;
  --light-color: #ecf0f1;
  --danger-color: #e74c3c;
  --warning-color: #f39c12;
}

body {
  font-family: 'Nunito', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  background-color: #f8f9fa;
  color: #333;
  line-height: 1.6;
}

.main-container {
  min-height: 85vh;
  padding: 2rem 0;
}

.card {
  border-radius: 8px;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 15px rgba(0, 0, 0, 0.1);
}

.btn {
  border-radius: 4px;
  transition: all 0.3s ease;
}

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

.btn-success {
  background-color: var(--secondary-color);
  border-color: var(--secondary-color);
}

.btn-danger {
  background-color: var(--danger-color);
  border-color: var(--danger-color);
}

.navbar {
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.navbar-brand {
  font-weight: 700;
  color: var(--primary-color) !important;
}

.table {
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
}

.table thead {
  background-color: var(--light-color);
}

.file-item {
  margin-bottom: 1.5rem;
}

.file-preview {
  height: 200px;
  object-fit: cover;
  border-radius: 4px;
}

.login-form {
  max-width: 400px;
  margin: 0 auto;
  padding: 2rem;
}

.form-control:focus {
  border-color: var(--primary-color);
  box-shadow: 0 0 0 0.2rem rgba(52, 152, 219, 0.25);
}

footer {
  background-color: var(--dark-color);
  color: white;
  padding: 1.5rem 0;
}

.page-title {
  color: var(--dark-color);
  margin-bottom: 1.5rem;
  position: relative;
  padding-bottom: 10px;
}

.page-title:after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  height: 3px;
  width: 60px;
  background-color: var(--primary-color);
}

/* 动画效果 */
.fade-in {
  animation: fadeIn 0.5s ease-in;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* 自适应 */
@media (max-width: 768px) {
  .file-item {
    margin-bottom: 2rem;
  }
}

.action-btn {
  margin-right: 5px;
}

.action-btn i {
  margin-right: 3px;
}

.preview-thumbnail {
  max-width: 100px;
  max-height: 60px;
  object-fit: cover;
  border-radius: 4px;
}

.file-badge {
  position: absolute;
  top: 10px;
  right: 10px;
  z-index: 10;
}