.jumbotron{
    cursor: pointer;
    width: 10rem; /* 设置宽度为300px */
    height: 10rem; /* 设置高度为300px，与宽度相等，确保为正方形 */
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0; /* 取消默认的内边距 */
}
#recentlyLearning {
    display: none;
}

#recentlyLearningArticle {
    text-decoration: underline;
}
.jumbotron {
    transition: transform 0.2s, box-shadow 0.2s;
    min-width: 140px;
    max-width: 170px;
}
.jumbotron:hover {
    transform: translateY(-5px);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.1);
}
#card-container {
    flex-wrap: wrap;
    gap: 20px;
}
#recentlyLearning h6 {
    font-size: 0.9rem;
}

/* 名人名言遮罩层样式 - 简约白色风格 */
.quote-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.6);
    display: none; /* 默认隐藏 */
    align-items: center;
    justify-content: center;
    z-index: 9999;
    backdrop-filter: blur(8px);
    animation: fadeIn 0.5s ease-in-out;
}

.quote-container {
    background: white;
    border: 1px solid #e9ecef;
    border-radius: 20px;
    padding: 40px;
    max-width: 600px;
    width: 90%;
    text-align: center;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
    position: relative;
    animation: slideIn 0.6s ease-out;
}

.quote-content {
    margin-bottom: 30px;
}

.quote-text {
    font-size: 1.5rem;
    font-weight: 300;
    line-height: 1.6;
    color: #333;
    margin-bottom: 20px;
    font-style: italic;
}

.quote-author {
    font-size: 1.1rem;
    color: #666;
    font-weight: 500;
}

.quote-controls {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 20px;
}

.countdown {
    color: #999;
    font-size: 0.9rem;
    font-weight: 500;
}

#countdownNumber {
    color: #999;
    font-weight: bold;
    font-size: 0.9rem;
}

.close-btn {
    background: #f8f9fa;
    border: 2px solid #e9ecef;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    color: #666;
    transition: all 0.3s ease;
}

.close-btn:hover {
    background: #e9ecef;
    border-color: #dee2e6;
    transform: scale(1.1);
}

.close-btn:active {
    transform: scale(0.95);
}

/* 动画效果 */
@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateY(-50px) scale(0.9);
    }
    to {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

/* 响应式设计 */
@media (max-width: 768px) {
    .quote-container {
        padding: 30px 20px;
        margin: 20px;
    }
    
    .quote-text {
        font-size: 1.2rem;
    }
    
    .quote-author {
        font-size: 1rem;
    }
    
    .quote-controls {
        flex-direction: column;
        gap: 15px;
    }
}