.container {
    width: 95%;
    max-width: 1200px;
    padding: 40px 20px;
    margin: 0 auto;
    position: relative;
}

.back-btn {
    position: absolute;
    top: 40px;
    right: 20px;
    background: white;
    border: 2px solid #999;
    color: #666;
    padding: 8px 16px;
    border-radius: 20px;
    text-decoration: none;
    font-size: 0.875rem;
    transition: all 0.3s;
    z-index: 10;
}

.back-btn:hover {
    background: #f5f5f5;
}

.card {
    background-color: #fff;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    overflow: hidden;
    padding: 20px;
    transition: box-shadow 0.3s ease, transform 0.3s ease;
}

.card:hover {
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
    transform: translateY(-2px);
}

.card img {
    border-radius: 6px;
    margin-top: 15px;
}

/* 卡片內標題降為 h3（外層頁面標題已是 h2），視覺沿用原本 h2 的樣式 */
.card .section-header h3 {
    color: #2c5484;
    font-size: 1.75rem;
    font-weight: bold;
    display: inline-block;
    border-bottom: 3px solid #2c5484;
    padding-bottom: 5px;
    margin: 0;
    letter-spacing: 2px;
}

.back-to-top {
    position: fixed;
    bottom: 40px;
    right: 20px;
    width: 42px;
    height: 42px;
    border-radius: 50%;
    background: #3730a3;
    color: #fff;
    border: none;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.125rem;
    box-shadow: 0 4px 12px rgba(55,48,163,0.35);
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.25s ease, transform 0.25s ease;
    z-index: 999;
}
.back-to-top.visible {
    opacity: 1;
    pointer-events: auto;
}
.back-to-top:hover {
    background: #4338ca;
    transform: translateY(-2px);
}