/* 헤더 스타일 */
.site-header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: var(--header-height);
    background-color: var(--bg-color);
    box-shadow: var(--shadow-sm);
    z-index: 1000;
    transition: all var(--transition-normal);
}

.header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 100%;
    padding: 0 var(--spacing-md);
}

/* 로고 */
.logo {
    padding: var(--spacing-sm) 0;
}

.logo img {
    width: 150px;
    height: auto;
}

/* 메인 네비게이션 */
.main-nav {
    margin-right: 60px;
    display: flex;
    align-items: center;
    height: 100%;
}

.nav-list {
    display: flex;
    height: 100%;
}

.nav-item {
    position: relative;
    height: 100%;
    display: flex;
    align-items: center;
}

.nav-item a {
    display: flex;
    align-items: center;
    height: 100%;
    padding: 0 var(--spacing-md);
    font-size: var(--font-size-base);
    /*text-transform: lowercase;*/
    letter-spacing: 0.5px;
    font-weight: var(--font-weight-medium);
    transition: color var(--transition-fast);
}

.nav-item a:hover {
    color: var(--accent-color);
}

.nav-item.active a {
    color: var(--accent-color);
    font-weight: var(--font-weight-bold);
}

/* 서브메뉴 */
.portfolio-menu {
    position: relative;
}

.sub-menu {
    position: absolute;
    top: 100%;
    left: 0;
    width: 200px;
    background-color: var(--bg-color);
    box-shadow: var(--shadow-md);
    visibility: hidden;
    opacity: 0;
    transform: translateY(10px);
    transition: all var(--transition-normal);
    z-index: 1001;
}

.portfolio-menu:hover .sub-menu {
    visibility: visible;
    opacity: 1;
    transform: translateY(0);
}

.sub-menu li {
    display: block;
    width: 100%;
}

.sub-menu a {
    display: block;
    padding: var(--spacing-sm) var(--spacing-md);
    width: 100%;
    height: auto;
    text-transform: none;
}

.sub-menu a:hover {
    background-color: var(--light-gray);
}

/* 모바일 메뉴 버튼 */
.mobile-menu-button {
    display: none;
    flex-direction: column;
    justify-content: space-between;
    width: 30px;
    height: 20px;
    cursor: pointer;
    z-index: 1002;
}

.mobile-menu-button span {
    display: block;
    width: 100%;
    height: 2px;
    background-color: var(--primary-color);
    transition: all var(--transition-normal);
}

.mobile-menu-button.active span:nth-child(1) {
    transform: translateY(9px) rotate(45deg);
}

.mobile-menu-button.active span:nth-child(2) {
    opacity: 0;
}

.mobile-menu-button.active span:nth-child(3) {
    transform: translateY(-9px) rotate(-45deg);
}

/* 모바일 메뉴 */
.mobile-menu {
    display: none;
    position: fixed;
    top: var(--header-height);
    left: 0;
    width: 100%;
    height: calc(100vh - var(--header-height));
    background-color: var(--bg-color);
    z-index: 999;
    transform: translateX(100%);
    transition: transform var(--transition-normal);
    overflow-y: auto;
}

.mobile-menu.active {
    transform: translateX(0);
}

.mobile-nav-list {
    padding: var(--spacing-md);
}

.mobile-nav-item {
    margin-bottom: var(--spacing-md);
}

.mobile-nav-item a {
    display: block;
    padding: var(--spacing-sm) 0;
    font-size: var(--font-size-md);
    font-weight: var(--font-weight-medium);
}

.portfolio-mobile-menu {
    margin-bottom: 0;
}

.mobile-sub-menu {
    padding-left: var(--spacing-md);
    margin-top: var(--spacing-sm);
}

.mobile-sub-menu li {
    margin-bottom: var(--spacing-sm);
}

.mobile-sub-menu a {
    font-size: var(--font-size-base);
}

/* 미디어 쿼리 - 태블릿 이하 */
@media (max-width: 991px) {
    .main-nav {
        display: none;
    }

    .mobile-menu-button {
        display: flex;
    }

    .mobile-menu {
        display: block;
    }
}

/* 스크롤 시 헤더 스타일 변경 */
.site-header.scrolled {
    height: 70px;
    box-shadow: var(--shadow-md);
}