:root {
    --ease_out_soft: cubic-bezier(0.22, 0.61, 0.36, 1);
    --ease_morph: cubic-bezier(0.65, 0.05, 0.36, 1);
    --char_stagger: 26ms;
    --item_stagger: 90ms;
}

/* 햄버거 아이콘 모핑 */
.menu_icon {
    position: relative;
    display: block;
    width: 22px;
    height: 16px;
}

.menu_icon_bar {
    position: absolute;
    left: 0;
    width: 100%;
    height: 2.4px;
    border-radius: 2px;
    background-color: #ffffff;
    transition:
        transform 0.38s var(--ease_morph),
        opacity 0.2s ease;
}

.menu_icon_bar:nth-child(1) {
    top: 0;
}

.menu_icon_bar:nth-child(2) {
    top: 6.8px;
}

.menu_icon_bar:nth-child(3) {
    top: 13.6px;
}

.header_menu_button.is_open .menu_icon_bar:nth-child(1) {
    transform: translateY(6.8px) rotate(45deg);
}

.header_menu_button.is_open .menu_icon_bar:nth-child(2) {
    opacity: 0;
    transform: scaleX(0.2);
}

.header_menu_button.is_open .menu_icon_bar:nth-child(3) {
    transform: translateY(-6.8px) rotate(-45deg);
}

/* 내비게이션 열림 + 메뉴 항목 순차 등장 */
.global_nav {
    opacity: 0;
    transform: translateY(-10px);
    transition:
        opacity 0.32s ease,
        transform 0.38s var(--ease_out_soft);
}

.global_nav.is_open {
    opacity: 1;
    transform: none;
}

.global_nav_list > li {
    opacity: 0;
    transform: translateY(-12px);
    transition:
        opacity 0.42s ease,
        transform 0.48s var(--ease_out_soft);
}

.global_nav.is_open .global_nav_list > li {
    opacity: 1;
    transform: none;
    transition-delay: calc(var(--nav_index, 0) * 65ms + 90ms);
}

/* 텍스트 스플릿 등장 */
.split_line {
    display: block;
}

.split_char {
    display: inline-block;
    opacity: 0;
    transform: translateY(0.5em);
    transition:
        opacity 0.5s ease,
        transform 0.62s var(--ease_out_soft);
}

.split_text.is_visible .split_char {
    opacity: 1;
    transform: none;
    transition-delay: calc(var(--char_index, 0) * var(--char_stagger));
}

/* 스크롤 진입 시 슬라이드업 페이드인 */
[data-reveal] {
    opacity: 0;
    transform: translateY(28px);
    transition:
        opacity 0.62s ease,
        transform 0.72s var(--ease_out_soft);
}

[data-reveal].is_visible {
    opacity: 1;
    transform: none;
    transition-delay: calc(var(--reveal_index, 0) * var(--item_stagger));
}

/* 모션 최소화 설정 존중 */
@media (prefers-reduced-motion: reduce) {
    .split_char,
    [data-reveal],
    .global_nav,
    .global_nav_list > li {
        opacity: 1;
        transform: none;
        transition: none;
    }
}