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

:root {
  --primary: #6366f1;
  --primary-dark: #4f46e5;
  --danger: #ef4444;
  --danger-dark: #dc2626;
  --success: #22c55e;
  --bg: #f5f7fa;
  --card: #ffffff;
  --text: #1f2937;
  --text-light: #6b7280;
  --border: #e5e7eb;
  --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  --radius: 8px;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
}

/* ========== 登录页样式 ========== */
.login-container {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  padding: 20px;
}

.login-card {
  background: var(--card);
  border-radius: 16px;
  box-shadow: var(--shadow-lg);
  padding: 48px 40px;
  width: 100%;
  max-width: 420px;
}

.login-logo {
  text-align: center;
  margin-bottom: 32px;
}

.login-logo h1 {
  font-size: 28px;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 8px;
}

.login-logo p {
  color: var(--text-light);
  font-size: 14px;
}

.form-group {
  margin-bottom: 20px;
}

.form-group label {
  display: block;
  font-size: 14px;
  font-weight: 500;
  color: var(--text);
  margin-bottom: 8px;
}

.form-group input {
  width: 100%;
  padding: 12px 16px;
  border: 2px solid var(--border);
  border-radius: var(--radius);
  font-size: 15px;
  transition: border-color 0.2s, box-shadow 0.2s;
  outline: none;
}

.form-group input:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.form-group input:disabled {
  background: #f9fafb;
  cursor: not-allowed;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  padding: 12px 24px;
  border: none;
  border-radius: var(--radius);
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
}

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

.btn-primary:hover:not(:disabled) {
  background: var(--primary-dark);
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(99, 102, 241, 0.3);
}

.btn-primary:disabled {
  background: #9ca3af;
  cursor: not-allowed;
}

.btn-secondary {
  background: #f3f4f6;
  color: var(--text);
  border: 1px solid var(--border);
}

.btn-secondary:hover {
  background: #e5e7eb;
}

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

.btn-danger:hover {
  background: var(--danger-dark);
}

.btn-sm {
  width: auto;
  padding: 6px 12px;
  font-size: 13px;
}

.alert {
  padding: 12px 16px;
  border-radius: var(--radius);
  margin-bottom: 20px;
  font-size: 14px;
}

.alert-error {
  background: #fef2f2;
  color: var(--danger-dark);
  border: 1px solid #fecaca;
}

.alert-success {
  background: #f0fdf4;
  color: #166534;
  border: 1px solid #bbf7d0;
}

.alert-warning {
  background: #fffbeb;
  color: #92400e;
  border: 1px solid #fde68a;
}

.login-info {
  text-align: center;
  margin-top: 24px;
  font-size: 12px;
  color: var(--text-light);
}

.login-info .attempts {
  font-weight: 600;
  color: var(--danger);
}

/* ========== 管理页面样式 ========== */
.admin-container {
  min-height: 100vh;
  display: flex;
}

.admin-sidebar {
  width: 260px;
  background: var(--card);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  flex-shrink: 0;
}

.sidebar-header {
  padding: 24px 20px;
  border-bottom: 1px solid var(--border);
}

.sidebar-header h2 {
  font-size: 18px;
  font-weight: 700;
  color: var(--text);
}

.category-list {
  flex: 1;
  overflow-y: auto;
  padding: 12px;
}

.category-item {
  display: flex;
  align-items: center;
  padding: 10px 12px;
  border-radius: var(--radius);
  cursor: pointer;
  transition: background 0.15s;
  margin-bottom: 4px;
}

.category-item:hover {
  background: #f3f4f6;
}

.category-item.active {
  background: #eef2ff;
  color: var(--primary);
}

.category-item .icon {
  margin-right: 10px;
  font-size: 18px;
}

.category-item .name {
  flex: 1;
  font-size: 14px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.category-item .count {
  font-size: 12px;
  color: var(--text-light);
  margin-right: 8px;
}

.category-item .delete-btn {
  opacity: 0;
  background: none;
  border: none;
  color: var(--danger);
  cursor: pointer;
  padding: 2px;
  font-size: 16px;
  transition: opacity 0.15s;
}

.category-item:hover .delete-btn {
  opacity: 1;
}

.sidebar-actions {
  padding: 16px;
  border-top: 1px solid var(--border);
}

.add-category-btn {
  width: 100%;
  padding: 10px;
  background: #f3f4f6;
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  color: var(--text-light);
  font-size: 14px;
  cursor: pointer;
  transition: all 0.2s;
}

.add-category-btn:hover {
  background: #eef2ff;
  border-color: var(--primary);
  color: var(--primary);
}

.admin-main {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.main-header {
  background: var(--card);
  border-bottom: 1px solid var(--border);
  padding: 16px 28px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.main-header h1 {
  font-size: 20px;
  font-weight: 600;
}

.header-actions {
  display: flex;
  gap: 12px;
  align-items: center;
}

.upload-area {
  flex: 1;
  padding: 28px;
  overflow-y: auto;
}

.empty-state {
  text-align: center;
  padding: 60px 20px;
  color: var(--text-light);
}

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

.dropzone {
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  padding: 40px;
  text-align: center;
  margin-bottom: 24px;
  cursor: pointer;
  transition: all 0.2s;
  background: var(--card);
}

.dropzone:hover,
.dropzone.dragging {
  border-color: var(--primary);
  background: #fafaff;
}

.dropzone .dropzone-icon {
  font-size: 36px;
  margin-bottom: 12px;
  color: var(--text-light);
}

.dropzone p {
  color: var(--text-light);
  font-size: 14px;
}

.dropzone .dropzone-hint {
  font-size: 12px;
  margin-top: 4px;
}

.image-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 16px;
}

.image-card {
  background: var(--card);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: transform 0.2s, box-shadow 0.2s;
  position: relative;
}

.image-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.image-card img {
  width: 100%;
  aspect-ratio: 1;
  object-fit: cover;
  display: block;
}

.image-card .image-info {
  padding: 10px 12px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.image-card .image-name {
  font-size: 13px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  flex: 1;
  margin-right: 8px;
}

.image-card .image-delete {
  background: none;
  border: none;
  color: var(--danger);
  cursor: pointer;
  font-size: 18px;
  padding: 4px;
  border-radius: 4px;
  transition: background 0.15s;
}

.image-card .image-delete:hover {
  background: #fef2f2;
}

/* ========== 模态框样式 ========== */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.5);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  padding: 20px;
}

.modal {
  background: var(--card);
  border-radius: 12px;
  box-shadow: var(--shadow-lg);
  width: 100%;
  max-width: 400px;
  overflow: hidden;
}

.modal-header {
  padding: 20px 24px;
  border-bottom: 1px solid var(--border);
}

.modal-header h3 {
  font-size: 18px;
  font-weight: 600;
}

.modal-body {
  padding: 24px;
}

.modal-body p {
  color: var(--text-light);
  font-size: 14px;
}

.modal-body input {
  width: 100%;
  padding: 10px 14px;
  border: 2px solid var(--border);
  border-radius: var(--radius);
  font-size: 14px;
  outline: none;
  margin-top: 12px;
}

.modal-body input:focus {
  border-color: var(--primary);
}

.modal-footer {
  padding: 16px 24px;
  border-top: 1px solid var(--border);
  display: flex;
  gap: 12px;
  justify-content: flex-end;
}

.modal-footer .btn {
  width: auto;
  padding: 8px 20px;
}

/* ========== 加载状态 ========== */
.loading {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 40px;
  color: var(--text-light);
}

.spinner {
  width: 32px;
  height: 32px;
  border: 3px solid var(--border);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
  margin-right: 12px;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* ========== 响应式 ========== */
@media (max-width: 768px) {
  .admin-container {
    flex-direction: column;
  }
  
  .admin-sidebar {
    width: 100%;
    max-height: 200px;
  }
  
  .image-grid {
    grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  }
  
  .login-card {
    padding: 32px 24px;
  }
}

/* ========== 工具类 ========== */
.hidden {
  display: none !important;
}

.text-center {
  text-align: center;
}

.mt-16 { margin-top: 16px; }
.mt-24 { margin-top: 24px; }