/* 数学口算题出题系统 - 样式文件 */

body {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    font-family: 'Microsoft YaHei', 'PingFang SC', 'Helvetica Neue', Arial, sans-serif;
    padding: 10px;
}

.container-fluid {
    max-width: 1400px;
    margin: 0 auto;
}

.header-section {
    background: rgba(255, 255, 255, 0.95);
    border-radius: 15px;
    margin: 20px 0;
    backdrop-filter: blur(10px);
    box-shadow: 0 8px 32px rgba(31, 38, 135, 0.37);
}

.card {
    border: none;
    border-radius: 15px;
    backdrop-filter: blur(10px);
    background: rgba(255, 255, 255, 0.95);
    margin-bottom: 20px;
}

.card-header {
    border-radius: 15px 15px 0 0 !important;
    border-bottom: 2px solid rgba(255, 255, 255, 0.2);
}

.btn {
    border-radius: 25px;
    padding: 12px 30px;
    font-weight: 600;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.15);
}

.btn-success {
    background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    border: none;
}

.btn-outline-primary {
    border: 2px solid #667eea;
    color: #667eea;
    background: transparent;
}

.btn-outline-primary:hover {
    background: #667eea;
    border-color: #667eea;
}

.form-control {
    border-radius: 10px;
    border: 2px solid #e9ecef;
    padding: 12px 16px;
    transition: all 0.3s ease;
}

.form-control:focus {
    border-color: #667eea;
    box-shadow: 0 0 0 0.2rem rgba(102, 126, 234, 0.25);
}

.input-group-text {
    border-radius: 0 10px 10px 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    font-weight: 500;
    text-align: center;
    font-size: 14px;
    min-width: 50px;
}

.input-group .form-control {
    border-radius: 10px 0 0 10px;
}

.input-group .form-control:not(:last-child) {
    border-radius: 0;
}

.input-group {
    margin-bottom: 15px;
}

.form-label {
    font-weight: 600;
    color: #495057;
    margin-bottom: 8px;
}

.card-body {
    padding: 2rem;
}

.row.mb-4 {
    margin-bottom: 2rem !important;
}

.validation-alert {
    border-radius: 10px;
    border: none;
    font-size: 14px;
    animation: slideIn 0.3s ease-out;
}

.validation-alert.alert-warning {
    background: linear-gradient(135deg, #ffeaa7 0%, #fdcb6e 100%);
    color: #2d3436;
}

.validation-alert.alert-success {
    background: linear-gradient(135deg, #00b894 0%, #00cec9 100%);
    color: white;
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.btn-secondary {
    background: linear-gradient(135deg, #636e72 0%, #2d3436 100%);
    border: none;
}

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

.text-primary {
    color: #667eea !important;
}

.bg-primary {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%) !important;
}

.bg-info {
    background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%) !important;
}

.bg-warning {
    background: linear-gradient(135deg, #fa709a 0%, #fee140 100%) !important;
}

.preview-table {
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.preview-table th {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    padding: 15px;
    font-weight: 600;
}

.preview-table td {
    padding: 15px;
    border-bottom: 1px solid #e9ecef;
    font-family: 'Courier New', monospace;
    font-size: 16px;
    font-weight: 500;
}

.preview-table tbody tr:hover {
    background-color: rgba(102, 126, 234, 0.1);
}

.spinner-border {
    width: 3rem;
    height: 3rem;
}

.modal-content {
    border-radius: 15px;
    border: none;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
}

.alert {
    border-radius: 10px;
    border: none;
    padding: 15px 20px;
}

.alert-success {
    background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    color: white;
}

.alert-danger {
    background: linear-gradient(135deg, #fa709a 0%, #fee140 100%);
    color: white;
}

/* 响应式设计 */
@media (max-width: 768px) {
    body {
        padding: 5px;
    }
    
    .header-section h1 {
        font-size: 2rem;
    }
    
    .btn-lg {
        padding: 10px 20px;
        font-size: 1rem;
    }
    
    .input-group-text {
        font-size: 0.875rem;
        min-width: 45px;
    }
    
    .container-fluid {
        padding: 0 10px;
    }
}

@media (max-width: 576px) {
    .input-group-text {
        min-width: 40px;
        font-size: 0.8rem;
    }
    
    .col-lg-8, .col-lg-4 {
        margin-bottom: 20px;
    }
    
    .col-lg-6 {
        margin-bottom: 15px;
    }
}

/* 动画效果 */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.card {
    animation: fadeInUp 0.6s ease-out;
}

.card:nth-child(2) {
    animation-delay: 0.1s;
}

.card:nth-child(3) {
    animation-delay: 0.2s;
}