.header,
.header * {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: 'Noto Sans KR', sans-serif;
    background-color: #ffffff;
    color: #333333;
}

.header {
    background-color: #ffffff;
    border-bottom: 1px solid #e0e0e0;
    position: relative;
    z-index: 10;
}

.header-inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 40px;
}

.logo-area {
    display: flex;
    align-items: center;
    text-decoration: none;
    gap: 12px;
}

.logo-area img {
    height: 36px;
}

.logo-text_main {
    font-weight: bold;
    font-size: 14px;
    color: #666;
    user-select: none;
}

.logo-text_sub {
    font-size: 11px;
    color: #666;
    user-select: none;
}

.nav-menu {
    display: flex;
    gap: 20px;
}

.nav-item {
    position: relative;
    color: #000;
    text-decoration: none;
    font-weight: bold;
    font-size: clamp(10px, 1.2vw, 18px);
    padding: 10px;
    display: block;
    user-select: none;
}

.nav-item a {
    color: #000;
    text-decoration: none;
    user-select: none;
}

.nav-item a:hover {
    color: #006400;
}

.nav-item:hover {
    color: #006400;
}

.header-navigation {
    display: flex;
    gap: 10px;
}

.header-navigation a {
    font-size: 13px;
    color: #000;
    text-decoration: none;
    user-select: none;
}

.header-navigation a:hover {
    color: #006400;
}

.dropdown-container {
    position: absolute;
    top: 100%;
    left: 0;
    width: 100%;
    z-index: 1000;
    pointer-events: none;
}

.dropdown-container.active {
    pointer-events: auto;
}

.dropdown-panel {
    background-color: #f5f5f5;
    overflow: hidden;
    max-height: 0;
    opacity: 0;
    transform: translateY(-10px);
    transition: all 0.4s ease;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    min-height: 150px;
}

.dropdown-container.active .dropdown-panel {
    max-height: 700px;
    opacity: 1;
    transform: translateY(0);
}

.dropdown-content {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    padding: 40px 40px;
    gap: 40px;
}



.left-column {
    flex: 1;
    min-width: 200px;

}

.left-column h4 {
    font-size: 24px;
    color: #000;
    margin-bottom: 10px;
    user-select: none;
}

.left-column p {
    font-size: 14px;
    line-height: 1.6;
    user-select: none;
}

.left-column2 {
    min-width: 200px;

}

.left-column2 h4 {
    font-size: 24px;
    color: #000;
    margin-bottom: 10px;
    user-select: none;
}

.left-column2 p {
    font-size: 14px;
    line-height: 1.6;
    user-select: none;
}

.center-column {
    flex: 2;
    display: flex;
    flex-direction: column;
    gap: 4px;
    min-width: 300px;
}

.center-column {
    display: grid;
    grid-auto-flow: column;
    grid-template-rows: repeat(5, auto);
    /* 5개까지는 세로로 */
    gap: 10px 40px;
}

.center-column a {
    font-size: 16px;
    color: #333;
    text-decoration: none;
    padding: 6px 4px;
    user-select: none;
}

.center-column a:hover {
    color: #006400;
}

.center-column.majors {
    display: flex;
    flex-direction: row;
    flex-wrap: wrap;

    justify-content: space-evenly;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0px;
    align-items: flex-start;
}



.major-group {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    justify-content: flex-start;
}

.major-group h5 {
    font-size: 20px;
    font-weight: bold;
    color: #006400;
    margin-bottom: 12px;
    margin-top: 12px;
    user-select: none;
}

.major-group ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.major-group li {
    font-size: 17px;
    color: #222;
    padding: 3px 0;
    cursor: pointer;
    line-height: 1.4;
    transition: color 0.2s ease;
    user-select: none;
}

.major-group li:hover {
    color: #006400;
    min-width: auto;
}

.right-column {
    flex: 1;
    min-width: 200px;
}

.right-column iframe {
    width: 100%;
    max-width: 400px;
    aspect-ratio: 16 / 9;
    border: none;
    border-radius: 8px;
    vertical-align: top;
}

/* iframe이 아래로 쳐지지 않도록 */
.right-column iframe {
    vertical-align: top;
}

/* 드롭다운 콘텐츠 내 컬럼 정렬 안정화 */
.dropdown-content>div {
    align-self: flex-start;
}

/* 모바일 사이드바 및 햄버거 버튼 */
.hamburger {
    display: none;
    font-size: 24px;
    background: none;
    border: none;
    cursor: pointer;
    z-index: 998;
}

/* 사이드바 - 오른쪽에서 등장 */
.mobile-sidebar {
    position: fixed;
    top: 0;
    right: 0;
    width: 270px;
    height: 100%;
    background-color: #ffffff;
    transform: translateX(100%);
    transition: transform 0.35s ease;
    z-index: 999;
    overflow-y: auto;
}

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

.sidebar-inner {
    padding: 20px;
    opacity: 0;
    transform: translateX(20px);
    transition: all 0.3s ease;
}

.mobile-sidebar.active .sidebar-inner {
    opacity: 1;
    transform: translateX(0);
}

/* 사이드바 로고 아래 구분선 */
.mobile-sidebar .logo-area {
    border-bottom: 1px solid #ccc;
    padding-bottom: 18px;

}

.mobile-sidebar .logo-text_main {
    font-size: 13px;
    font-weight: bold;
}

.mobile-sidebar .logo-text_sub {
    font-size: 11px;
    color: #666;
}

.close-sidebar {
    font-size: 24px;
    background: none;
    border: none;
    cursor: pointer;
    float: right;
    margin-bottom: 10px;
}

.sidebar-menu {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.sidebar-item {
    display: flex;
    flex-direction: column;
}

.sidebar-link {
    background: none;
    border: none;
    font-size: 16px;
    text-align: left;
    padding: 8px 0;
    cursor: pointer;
    text-decoration: none;
    color: #222;
    transition: color 0.2s ease;
}

.sidebar-link:hover {
    color: #006400;
}

.submenu {
    display: none;
    flex-direction: column;
    padding-left: 12px;
    margin-top: 6px;
}

.submenu a {
    font-size: 14px;
    color: #444;
    text-decoration: none;
    padding: 4px 0;
}

.submenu a:hover {
    color: #006400;
}

.submenu-group {
    margin-bottom: 12px;
    display: flex;
    flex-direction: column;
    border-bottom: 1px solid #006400;
    padding-bottom: 5px;
    margin-bottom: 10px;
}

.submenu-title {
    font-weight: bold;
    font-size: 18px;
    color: #006400;
    margin-bottom: 6px;
    margin-top: 10px;
}

/* 펼쳐졌을 때 */
.sidebar-item.active .submenu {
    display: flex;
}

/* 흐림 효과용 오버레이 */
.overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    backdrop-filter: blur(4px);
    background: rgba(0, 0, 0, 0.2);
    z-index: 998;
    display: none;
}

@media (max-width: 1225px) {
    .nav-item {
        font-size: clamp(10px, 1.2vw, 14px);
        padding: 3px;
    }

    .nav-menu {
        display: flex;
        gap: 10px;
    }

    .nav-item a {
        font-size: 12px;
    }

    .major-group h5 {
        font-size: 14px;
    }

    .major-group li {
        font-size: 13px;
    }
}

@media (max-width: 1024px) {
    .header-inner {
        padding: 10px 20px;
        gap: 8px;
    }

    .logo-area img {
        height: 28px;
    }

    .logo-text_main {
        font-size: 12px;
    }

    .logo-text_sub {
        font-size: 10px;
    }

    .nav-menu {
        gap: 10px;
    }

    .nav-item {
        font-size: 14px;
        padding: 6px;
    }

    .header-navigation a {
        font-size: 12px;
    }

    .dropdown-panel {
        min-height: 150px;
        max-height: 400px;
        overflow-y: auto;
    }

    .dropdown-content {
        padding: 20px 24px;
        gap: 16px;
    }

    .left-column {
        min-width: 160px;
    }

    .left-column h4 {
        font-size: 18px;
    }

    .left-column p {
        font-size: 12px;
    }

    .left-column2 {
        min-width: 160px;
    }

    .left-column2 h4 {
        font-size: 18px;
    }

    .left-column2 p {
        font-size: 12px;
    }

    .center-column {
        min-width: 240px;
        gap: 4px;
    }

    .center-column a {
        font-size: 13px;
    }

    .center-column.majors {
        gap: 24px;
    }

    .major-group {
        min-width: auto;
    }

    .major-group h5 {
        font-size: 15px;
    }

    .major-group li {
        font-size: 13px;
    }

    .right-column {
        min-width: 200px;
    }

    .right-column iframe {
        width: 100%;
        aspect-ratio: 16 / 9;
    }
}

@media (max-width: 1022px) {

    /* 헤더 내부 여백 및 정렬 */
    .header-inner {
        padding: 8px 12px;
        gap: 6px;
    }

    /* 로고 영역 */
    .logo-area img {
        height: 24px;
    }

    .logo-text_main {
        font-size: 10px;
    }

    .logo-text_sub {
        font-size: 7px;
    }

    /* 네비게이션 메뉴 */
    .nav-menu {
        gap: 4px;
    }

    .nav-item {
        font-size: 11px;
        padding: 4px;
    }

    .nav-item a {
        font-size: 11px;
    }

    /* 유틸 링크 (Home, 학생, 교직원 등) */
    .header-navigation a {
        font-size: 10px;
    }

    /* 드롭다운 영역 */
    .dropdown-content {
        padding: 16px 12px;
        gap: 12px;
    }

    .left-column {
        min-width: 130px;
    }

    .left-column h4 {
        font-size: 14px;
    }

    .left-column p {
        font-size: 11px;
    }

    .left-column2 {
        min-width: 130px;
    }

    .left-column2 h4 {
        font-size: 14px;
    }

    .left-column2 p {
        font-size: 11px;
    }

    .center-column {
        min-width: 190px;
        gap: 2px;
    }

    .center-column a {
        font-size: 11.5px;
    }

    .center-column.majors {
        gap: 14px;
        flex-wrap: wrap;
    }

    .major-group {
        min-width: 80px;
    }

    .major-group h5 {
        font-size: 13px;
    }

    .major-group li {
        font-size: 11.5px;
    }

}

/* 햄버거 활성화 */
@media (max-width: 767px) {
    .hamburger {
        display: block;
    }

    .nav-menu,
    .header-navigation {
        display: none !important;
    }
}