/* ========================================
   待办事项管理系统 - 美化样式
   ======================================== */

/* ===== 全局变量定义 ===== */
:root {
    /* 主色调 */
    --primary-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --primary-color: #667eea;
    --primary-dark: #5568d3;
    --primary-light: #8b9ff0;

    /* 辅助色 */
    --success-color: #4CAF50;
    --warning-color: #FF9800;
    --danger-color: #f44336;
    --info-color: #2196F3;

    /* 中性色 */
    --text-primary: #2c3e50;
    --text-secondary: #7f8c8d;
    --text-light: #95a5a6;
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --bg-tertiary: #e9ecef;
    --border-color: #dee2e6;

    /* 阴影 */
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.08);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.12);
    --shadow-xl: 0 12px 40px rgba(0, 0, 0, 0.15);

    /* 圆角 */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 20px;

    /* 间距 */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;
}

/* ===== 全局样式增强 ===== */
* {
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ===== 按钮美化 ===== */
.btn {
    border: none;
    outline: none;
    cursor: pointer;
    font-weight: 600;
    letter-spacing: 0.3px;
    text-transform: none;
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.3);
    transform: translate(-50%, -50%);
    transition: width 0.6s, height 0.6s;
}

.btn:active::before {
    width: 300px;
    height: 300px;
}

.btn-primary {
    background: var(--primary-gradient);
    color: white;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(102, 126, 234, 0.5);
}

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

.btn-success {
    background: linear-gradient(135deg, #4CAF50 0%, #45a049 100%);
    color: white;
    box-shadow: 0 4px 15px rgba(76, 175, 80, 0.4);
}

.btn-success:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(76, 175, 80, 0.5);
}

.btn-danger {
    background: linear-gradient(135deg, #f44336 0%, #d32f2f 100%);
    color: white;
    box-shadow: 0 4px 15px rgba(244, 67, 54, 0.4);
}

.btn-danger:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(244, 67, 54, 0.5);
}

.btn-secondary {
    background: linear-gradient(135deg, #6c757d 0%, #5a6268 100%);
    color: white;
    box-shadow: 0 4px 15px rgba(108, 117, 125, 0.4);
}

.btn-secondary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(108, 117, 125, 0.5);
}

/* ===== 输入框美化 ===== */
.form-control {
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 12px 16px;
    font-size: 15px;
    transition: all 0.3s ease;
    background: var(--bg-primary);
}

.form-control:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 4px rgba(102, 126, 234, 0.1);
    transform: translateY(-1px);
}

.form-control::placeholder {
    color: var(--text-light);
}

/* ===== 卡片美化 ===== */
.card {
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    padding: var(--spacing-lg);
    border: 1px solid var(--border-color);
}

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

/* ===== Alert美化 ===== */
.alert {
    border-radius: var(--radius-md);
    padding: var(--spacing-md) var(--spacing-lg);
    margin-bottom: var(--spacing-md);
    border-left: 4px solid;
    display: flex;
    align-items: center;
    animation: slideInDown 0.4s ease;
}

.alert-success {
    background: linear-gradient(135deg, #d4edda 0%, #c3e6cb 100%);
    border-left-color: var(--success-color);
    color: #155724;
}

.alert-error {
    background: linear-gradient(135deg, #f8d7da 0%, #f5c6cb 100%);
    border-left-color: var(--danger-color);
    color: #721c24;
}

.alert-warning {
    background: linear-gradient(135deg, #fff3cd 0%, #ffeaa7 100%);
    border-left-color: var(--warning-color);
    color: #856404;
}

.alert-info {
    background: linear-gradient(135deg, #d1ecf1 0%, #bee5eb 100%);
    border-left-color: var(--info-color);
    color: #0c5460;
}

/* ===== 动画定义 ===== */
@keyframes slideInDown {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes slideInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

@keyframes scaleIn {
    from {
        opacity: 0;
        transform: scale(0.9);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

@keyframes pulse {
    0%, 100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.05);
    }
}

@keyframes shimmer {
    0% {
        background-position: -1000px 0;
    }
    100% {
        background-position: 1000px 0;
    }
}

/* ===== 加载动画 ===== */
.loading-spinner {
    border: 4px solid rgba(255, 255, 255, 0.3);
    border-top-color: white;
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

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

/* ===== 模态框美化 ===== */
.modal {
    animation: fadeIn 0.3s ease;
}

.modal-content {
    animation: scaleIn 0.3s ease;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-xl);
    border: none;
}

.modal-header {
    background: var(--primary-gradient);
    color: white;
    border-radius: var(--radius-lg) var(--radius-lg) 0 0;
    padding: var(--spacing-lg);
}

.modal-title {
    font-size: 20px;
    font-weight: 600;
}

.modal-body {
    padding: var(--spacing-xl);
}

.modal-footer {
    padding: var(--spacing-lg);
    border-top: 1px solid var(--border-color);
}

/* ===== 徽章美化 ===== */
.badge {
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

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

.badge-success {
    background: linear-gradient(135deg, #4CAF50 0%, #45a049 100%);
    color: white;
}

.badge-warning {
    background: linear-gradient(135deg, #FF9800 0%, #F57C00 100%);
    color: white;
}

.badge-danger {
    background: linear-gradient(135deg, #f44336 0%, #d32f2f 100%);
    color: white;
}

.badge-info {
    background: linear-gradient(135deg, #2196F3 0%, #1976D2 100%);
    color: white;
}

/* ===== 表格美化 ===== */
.table {
    width: 100%;
    border-collapse: separate;
    border-spacing: 0;
    background: white;
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-md);
}

.table thead {
    background: var(--primary-gradient);
    color: white;
}

.table thead th {
    padding: var(--spacing-md);
    text-align: left;
    font-weight: 600;
    text-transform: uppercase;
    font-size: 12px;
    letter-spacing: 0.5px;
}

.table tbody tr {
    border-bottom: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

.table tbody tr:hover {
    background: var(--bg-secondary);
    transform: scale(1.01);
}

.table tbody td {
    padding: var(--spacing-md);
}

/* ===== 工具类 ===== */
.text-gradient {
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.shadow-sm { box-shadow: var(--shadow-sm); }
.shadow-md { box-shadow: var(--shadow-md); }
.shadow-lg { box-shadow: var(--shadow-lg); }
.shadow-xl { box-shadow: var(--shadow-xl); }

.rounded-sm { border-radius: var(--radius-sm); }
.rounded-md { border-radius: var(--radius-md); }
.rounded-lg { border-radius: var(--radius-lg); }
.rounded-xl { border-radius: var(--radius-xl); }

/* ===== 响应式优化 ===== */
@media (max-width: 768px) {
    .card {
        padding: var(--spacing-md);
    }

    .modal-content {
        margin: var(--spacing-sm);
    }

    .table {
        font-size: 14px;
    }

    .table thead th,
    .table tbody td {
        padding: var(--spacing-sm);
    }
}