/* 基础样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    color: #333;
}

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

/* 导航栏 */
.navbar {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 1000;
}

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

.nav-brand a {
    font-size: 1.5rem;
    font-weight: bold;
    color: #667eea;
    text-decoration: none;
}

.nav-menu {
    display: flex;
    gap: 1.5rem;
    align-items: center;
}

.nav-menu a {
    color: #333;
    text-decoration: none;
    transition: color 0.3s;
}

.nav-menu a:hover {
    color: #667eea;
}

.user-info {
    color: #666;
    font-weight: 500;
}

/* 主内容区 */
.main-content {
    margin: 2rem auto;
    background: white;
    border-radius: 10px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
    padding: 2rem;
    min-height: calc(100vh - 200px);
}

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

.card-title {
    font-size: 1.25rem;
    font-weight: bold;
    margin-bottom: 1rem;
    color: #333;
}

/* 表单样式 */
.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: #555;
}

.form-control {
    width: 100%;
    padding: 0.75rem;
    border: 2px solid #e0e0e0;
    border-radius: 6px;
    font-size: 1rem;
    transition: border-color 0.3s;
}

.form-control:focus {
    outline: none;
    border-color: #667eea;
}

.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 6px;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s;
    text-decoration: none;
    text-align: center;
}

.btn-primary {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4);
}

.btn-secondary {
    background: #6c757d;
    color: white;
}

.btn-secondary:hover {
    background: #5a6268;
}

.btn-block {
    width: 100%;
}

/* 消息提示 */
.alert {
    padding: 1rem;
    border-radius: 6px;
    margin-bottom: 1rem;
}

.alert-success {
    background: #d4edda;
    color: #155724;
    border: 1px solid #c3e6cb;
}

.alert-error {
    background: #f8d7da;
    color: #721c24;
    border: 1px solid #f5c6cb;
}

.alert-info {
    background: #d1ecf1;
    color: #0c5460;
    border: 1px solid #bee5eb;
}

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

.table th,
.table td {
    padding: 0.75rem;
    text-align: left;
    border-bottom: 1px solid #e0e0e0;
}

.table th {
    background: #f8f9fa;
    font-weight: 600;
    color: #555;
}

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

/* 网格布局 */
.grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin-top: 1.5rem;
}

.grid-item {
    background: #f8f9fa;
    padding: 1.5rem;
    border-radius: 8px;
    text-align: center;
    transition: transform 0.3s;
}

.grid-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

/* 页脚 */
.footer {
    background: rgba(255, 255, 255, 0.95);
    padding: 2rem 0;
    text-align: center;
    color: #666;
    margin-top: 3rem;
}

/* 响应式 */
@media (max-width: 768px) {
    .nav-menu {
        flex-direction: column;
        gap: 0.5rem;
    }
    
    .main-content {
        padding: 1rem;
    }
    
    .grid {
        grid-template-columns: 1fr;
    }
}

/* 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 1s ease-in-out infinite;
}

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