/* 全局样式 */
body {
    background-color: #f5f5f5;
}

/* 导航栏样式 */
.navbar {
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

/* 卡片样式 */
.card {
    margin-bottom: 20px;
    transition: transform 0.3s, box-shadow 0.3s;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    border: none;
    border-radius: 10px;
    overflow: hidden;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0,0,0,0.15);
}

.card-footer {
    background-color: #f8f9fa;
    border-top: none;
}

/* 题目卡片样式 */
.question-card {
    border-left: 4px solid #007bff;
    margin-bottom: 20px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

/* 表单样式 */
.form-check {
    margin-bottom: 8px;
}

.filter-section {
    background-color: white;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    margin-bottom: 20px;
}

.filter-section .form-label {
    font-weight: 500;
    margin-bottom: 8px;
}

/* 学科导航样式 */
.subject-nav {
    font-weight: bold;
    margin-bottom: 20px;
    background-color: #f0f0f0;
    border-radius: 5px;
    padding: 10px;
}

.subject-nav .nav-link {
    border-radius: 5px;
    margin: 0 5px;
}

.subject-nav .nav-link.active {
    background-color: #0d6efd;
    color: white;
}

/* 按钮样式 */
.btn-refresh {
    margin-left: 10px;
}

/* 题型徽章样式 */
.type-badge-单选 {
    background-color: #0d6efd;
}

.type-badge-填空 {
    background-color: #198754;
}

.type-badge-简答 {
    background-color: #dc3545;
}

.type-badge-计算 {
    background-color: #fd7e14;
}

.type-badge-证明 {
    background-color: #fd7e14;
}

.type-badge-判断 {
    background-color: #6f42c1;
}

/* 错题本样式 */
.list-group-item {
    border-left: 4px solid #dc3545;
    margin-bottom: 10px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

.badge-wrong-count {
    position: absolute;
    top: 10px;
    right: 10px;
}

.correct-answer {
    color: #198754;
    font-weight: bold;
}

.wrong-answer {
    color: #dc3545;
    text-decoration: line-through;
}

.subject-badge {
    font-size: 0.8rem;
    margin-left: 10px;
}

.subject-filter {
    min-width: 150px;
}

/* 首页特定样式 */
.feature-icon {
    font-size: 2.5rem;
    color: #0d6efd;
    margin-bottom: 1rem;
}

.subject-card .card-body {
    background-color: #f8f9fa;
    padding: 1.5rem;
}

.subject-card .icon {
    font-size: 3rem;
    margin-bottom: 1rem;
    color: #0d6efd;
}

.subject-card .card-title {
    font-weight: bold;
    margin-bottom: 0.5rem;
}

.subject-card .card-text {
    color: #6c757d;
    margin-bottom: 1.5rem;
}

.highlight-card {
    border: 2px solid #ffc107;
    position: relative;
}

.highlight-badge {
    position: absolute;
    top: -10px;
    right: -10px;
    background-color: #ffc107;
    color: #000;
    border-radius: 50%;
    width: 30px;
    height: 30px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    box-shadow: 0 2px 5px rgba(0,0,0,0.2);
}

.knowledge-card {
    background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
}

.knowledge-card .icon {
    color: #ffc107;
}

.knowledge-card .btn-primary {
    background-color: #ffc107;
    border-color: #ffc107;
    color: #000;
}

.knowledge-card .btn-primary:hover {
    background-color: #e0a800;
    border-color: #d39e00;
    color: #000;
}

/* 卡片图片样式 */
.card-img-top {
    height: 160px;
    object-fit: cover;
}

/* 工具类 */
.text-center-loading {
    text-align: center;
    padding: 2rem 0;
}

.spinner-container {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 200px;
}

/* 响应式样式 */
@media (max-width: 768px) {
    .subject-nav .nav-link {
        margin: 2px 0;
    }
    
    .filter-section {
        padding: 15px;
    }
    
    .card {
        margin-bottom: 15px;
    }
}