/* Apple-inspired Design System */
:root {
  --primary-color: #007AFF;
  --primary-hover: #0051D5;
  --success-color: #34C759;
  --danger-color: #FF3B30;
  --warning-color: #FF9500;
  --background: #F5F5F7;
  --card-background: #FFFFFF;
  --text-primary: #1D1D1F;
  --text-secondary: #86868B;
  --border-color: #D2D2D7;
  --shadow: 0 2px 16px rgba(0, 0, 0, 0.08);
  --shadow-hover: 0 4px 24px rgba(0, 0, 0, 0.12);
  --radius: 12px;
  --radius-small: 8px;
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Helvetica', 'Arial', sans-serif;
  background: var(--background);
  color: var(--text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

/* 卡片 */
.card {
  background: var(--card-background);
  border-radius: var(--radius);
  padding: 32px;
  box-shadow: var(--shadow);
  transition: var(--transition);
}

.card:hover {
  box-shadow: var(--shadow-hover);
}

.card-small {
  padding: 20px;
  border-radius: var(--radius-small);
}

/* 标题 */
h1, h2, h3, h4, h5, h6 {
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 16px;
}

h1 {
  font-size: 40px;
  letter-spacing: -0.5px;
}

h2 {
  font-size: 32px;
  letter-spacing: -0.3px;
}

h3 {
  font-size: 24px;
}

/* 表单 */
.form-group {
  margin-bottom: 24px;
}

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

input[type="text"],
input[type="password"],
input[type="email"],
textarea,
select {
  width: 100%;
  padding: 12px 16px;
  font-size: 16px;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-small);
  background: var(--card-background);
  color: var(--text-primary);
  transition: var(--transition);
  font-family: inherit;
}

input:focus,
textarea:focus,
select:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 4px rgba(0, 122, 255, 0.1);
}

input::placeholder {
  color: var(--text-secondary);
}

/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 24px;
  font-size: 16px;
  font-weight: 500;
  border: none;
  border-radius: var(--radius-small);
  cursor: pointer;
  transition: var(--transition);
  text-decoration: none;
  font-family: inherit;
  gap: 8px;
}

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

.btn-primary:hover {
  background: var(--primary-hover);
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(0, 122, 255, 0.3);
}

.btn-primary:active {
  transform: translateY(0);
}

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

.btn-success:hover {
  background: #28A745;
  transform: translateY(-1px);
}

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

.btn-danger:hover {
  background: #D32F2F;
  transform: translateY(-1px);
}

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

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

.btn-small {
  padding: 8px 16px;
  font-size: 14px;
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none !important;
}

/* 表格 */
table {
  width: 100%;
  border-collapse: collapse;
  background: var(--card-background);
  border-radius: var(--radius);
  overflow: hidden;
}

thead {
  background: var(--background);
}

th {
  padding: 16px;
  text-align: left;
  font-weight: 600;
  font-size: 14px;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

td {
  padding: 16px;
  border-top: 1px solid var(--border-color);
}

tr:hover {
  background: rgba(0, 0, 0, 0.02);
}

/* 导航 */
.nav {
  background: var(--card-background);
  padding: 16px 0;
  box-shadow: var(--shadow);
  margin-bottom: 32px;
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.nav-brand {
  font-size: 20px;
  font-weight: 600;
  color: var(--text-primary);
  text-decoration: none;
}

.nav-menu {
  display: flex;
  gap: 24px;
  list-style: none;
}

.nav-link {
  color: var(--text-primary);
  text-decoration: none;
  font-weight: 500;
  transition: var(--transition);
}

.nav-link:hover {
  color: var(--primary-color);
}

.nav-link.active {
  color: var(--primary-color);
}

/* 通知 */
.alert {
  padding: 16px 20px;
  border-radius: var(--radius-small);
  margin-bottom: 24px;
  display: flex;
  align-items: center;
  gap: 12px;
}

.alert-success {
  background: rgba(52, 199, 89, 0.1);
  color: var(--success-color);
  border: 1px solid rgba(52, 199, 89, 0.2);
}

.alert-error {
  background: rgba(255, 59, 48, 0.1);
  color: var(--danger-color);
  border: 1px solid rgba(255, 59, 48, 0.2);
}

.alert-warning {
  background: rgba(255, 149, 0, 0.1);
  color: var(--warning-color);
  border: 1px solid rgba(255, 149, 0, 0.2);
}

/* 加载动画 */
.loading {
  display: inline-block;
  width: 20px;
  height: 20px;
  border: 3px solid rgba(255, 255, 255, 0.3);
  border-radius: 50%;
  border-top-color: white;
  animation: spin 0.8s linear infinite;
}

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

/* 徽章 */
.badge {
  display: inline-block;
  padding: 4px 12px;
  font-size: 12px;
  font-weight: 600;
  border-radius: 12px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.badge-success {
  background: rgba(52, 199, 89, 0.1);
  color: var(--success-color);
}

.badge-danger {
  background: rgba(255, 59, 48, 0.1);
  color: var(--danger-color);
}

.badge-warning {
  background: rgba(255, 149, 0, 0.1);
  color: var(--warning-color);
}

.badge-info {
  background: rgba(0, 122, 255, 0.1);
  color: var(--primary-color);
}

/* 工具类 */
.text-center {
  text-align: center;
}

.text-secondary {
  color: var(--text-secondary);
}

.mt-1 { margin-top: 8px; }
.mt-2 { margin-top: 16px; }
.mt-3 { margin-top: 24px; }
.mt-4 { margin-top: 32px; }

.mb-1 { margin-bottom: 8px; }
.mb-2 { margin-bottom: 16px; }
.mb-3 { margin-bottom: 24px; }
.mb-4 { margin-bottom: 32px; }

.flex {
  display: flex;
}

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

.flex-center {
  display: flex;
  justify-content: center;
  align-items: center;
}

.gap-1 { gap: 8px; }
.gap-2 { gap: 16px; }
.gap-3 { gap: 24px; }

/* 响应式 */
@media (max-width: 768px) {
  .container {
    padding: 16px;
  }

  .card {
    padding: 24px;
  }

  h1 {
    font-size: 32px;
  }

  h2 {
    font-size: 24px;
  }

  .nav-menu {
    flex-direction: column;
    gap: 12px;
  }

  table {
    font-size: 14px;
  }

  th, td {
    padding: 12px 8px;
  }
}