/* ===== 动画样式区域 ===== */

/* 滚动动画 */
section {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.8s ease, transform 0.8s ease;
}

section.visible {
    opacity: 1;
    transform: translateY(0);
}

/* 汉堡菜单动画 */
.hamburger.active .ham-line:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}

.hamburger.active .ham-line:nth-child(2) {
    opacity: 0;
}

.hamburger.active .ham-line:nth-child(3) {
    transform: rotate(-45deg) translate(7px, -6px);
}

/* 移动菜单动画 */
.mobile-menu.active {
    display: flex;
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}