/* 自定义样式 */
.container {
    max-width: 1200px;
}

/* 确保页面至少占满整个视口高度 */
html, body {
    height: 100%;
}

body {
    display: flex;
    flex-direction: column;
}

main {
    flex: 1 0 auto;
}

footer {
    flex-shrink: 0;
}

/* 导航卡片悬停效果 */
.nav-card {
    transition: transform 0.2s ease-in-out;
}

.nav-card:hover {
    transform: translateY(-5px);
}

/* 链接动画效果 */
a {
    transition: color 0.2s ease-in-out;
}

/* 响应式调整 */
@media (max-width: 640px) {
    .container {
        padding-left: 1rem;
        padding-right: 1rem;
    }
}