/* 상단 고정 네비게이션 */
.top-nav {
    background-color: #fff;
    border-bottom: 1px solid #e9ecef;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    width: 100%;
    box-sizing: border-box;
}

.top-nav .container {
    width: 100%;
    margin: 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 2rem;
    box-sizing: border-box;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: #2c3e50;
    text-decoration: none;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    max-width: 200px;
}

.main-nav {
    display: flex;
    list-style: none;
    margin: 0;
    padding: 0;
}

.main-nav li {
    position: relative;
}

.main-nav a {
    display: block;
    padding: 1.5rem 1.2rem;
    color: #495057;
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
    white-space: nowrap;
}

.main-nav a:hover {
    color: #007bff;
}

.dropdown-menu {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    background: white;
    min-width: 200px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
    border-radius: 8px;
    z-index: 1001;
    border: 1px solid #e9ecef;
}

.main-nav li:hover .dropdown-menu {
    display: block;
}

.dropdown-menu a {
    padding: 0.75rem 1.2rem;
    border-bottom: 1px solid #f8f9fa;
}

.dropdown-menu a:last-child {
    border-bottom: none;
}

.dropdown-menu a:hover {
    background-color: #f8f9fa;
}

/* 메인 컨테이너 상단 여백 (고정 네비게이션 고려) */
.main-container {
    margin-top: 80px;
}

/* 햄버거 메뉴 버튼 (기본적으로 숨김) */
.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    color: #495057;
    cursor: pointer;
    padding: 0.5rem;
    border-radius: 4px;
    transition: all 0.3s ease;
    flex-shrink: 0;
}

.mobile-menu-btn:hover {
    background-color: #f8f9fa;
    color: #007bff;
}

/* 모바일 메뉴 오버레이 */
.mobile-menu-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: 999;
}

/* 반응형 디자인 */
@media (max-width: 768px) {
    .top-nav {
        width: 100vw;
        max-width: 100vw;
        overflow-x: hidden;
    }
    
    .top-nav .container {
        padding: 0 1rem;
        max-width: 100%;
        width: 100%;
        min-width: 0;
    }

    .logo {
        font-size: 1.2rem;
        max-width: 150px;
        flex-shrink: 1;
    }

    /* 햄버거 메뉴 버튼 표시 */
    .mobile-menu-btn {
        display: block;
        margin-left: auto;
    }

    /* 데스크톱 네비게이션 숨김 */
    .main-nav {
        display: none;
        position: fixed;
        top: 80px;
        left: 0;
        width: 100vw;
        max-width: 100vw;
        background: white;
        box-shadow: 0 4px 12px rgba(0,0,0,0.15);
        z-index: 1000;
        border-top: 1px solid #e9ecef;
        overflow-x: hidden;
        box-sizing: border-box;
    }

    /* 모바일 메뉴가 열렸을 때 */
    .main-nav.mobile-open {
        display: block;
    }

    .main-nav li {
        border-bottom: 1px solid #f8f9fa;
        width: 100%;
    }

    .main-nav li:last-child {
        border-bottom: none;
    }

    .main-nav a {
        padding: 1rem 1.5rem;
        border-bottom: 1px solid #f8f9fa;
        width: 100%;
        box-sizing: border-box;
    }

    /* 모바일에서 드롭다운 메뉴 */
    .dropdown-menu {
        position: static;
        display: none;
        box-shadow: none;
        border: none;
        background-color: #f8f9fa;
        border-radius: 0;
        margin-left: 0;
        width: 100%;
        min-width: 0;
        box-sizing: border-box;
        overflow: hidden;
    }

    /* 모바일에서는 hover 효과 비활성화 */
    .main-nav li:hover .dropdown-menu {
        display: none;
    }

    /* 모바일에서 드롭다운 토글 */
    .dropdown-menu.mobile-open {
        display: block !important;
    }

    .dropdown-menu a {
        padding: 0.75rem 1.5rem;
        border-bottom: 1px solid #e9ecef;
        width: 100%;
        box-sizing: border-box;
        white-space: nowrap;
        overflow: hidden;
        text-overflow: ellipsis;
    }
}

/* 매우 작은 화면 (320px 이하) */
@media (max-width: 320px) {
    .top-nav .container {
        padding: 0 0.5rem;
    }
    
    .logo {
        font-size: 1rem;
        max-width: 120px;
    }
    
    .mobile-menu-btn {
        padding: 0.3rem;
        font-size: 1.2rem;
    }

    .main-nav a {
        padding: 0.8rem 1rem;
    }

    .dropdown-menu a {
        padding: 0.6rem 1.2rem;
    }
}