nav {
    background-color: var(--background-color);
    width: 100%;
    position: fixed;
    top: 0;
    left: 0;
    z-index: 1000;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

nav .nav-content {
    width: 100%;
    padding: 0;
    display: flex;
    justify-content: center;
    align-items: center;
}

nav .nav-menu {
    list-style-type: none;
    padding: 0;
    margin: 0;
    display: flex;
    width: 100%;
    justify-content: space-around;
}

nav .nav-menu li {
    flex-grow: 1;
    text-align: center;
    position: relative;
}

nav a {
    color: var(--text-color);
    text-decoration: none;
    font-size: 14px;
    font-weight: 500;
    padding: 15px 0;
    display: block;
    transition: all 0.3s;
}

nav a:hover {
    background-color: var(--hover-color);
}

/* 선택된 메뉴 스타일 */
nav a.active {
    color: white;
    background-color: var(--primary-color);
}

/* 서브메뉴 스타일 */
.has-submenu {
    position: relative;
}

.submenu {
    position: absolute;
    top: 100%;
    left: 0;
    width: 100%;
    background-color: white;
    box-shadow: 0 4px 8px rgba(0,0,0,0.2);
    list-style: none;
    padding: 0;
    margin: 0;
    display: none;
    z-index: 100;
    border-radius: 0 0 4px 4px;
}

.submenu li {
    width: 100%;
    text-align: left;
}

.submenu a {
    padding: 12px 15px;
    font-size: 13px;
    border-bottom: 1px solid var(--border-color);
    display: block;
    transition: all 0.3s;
    color: var(--text-color);
}

.submenu a:hover {
    background-color: var(--hover-color);
    padding-left: 20px;
}

.submenu a.active {
    color: white;
    background-color: var(--primary-color);
}

/* 서브메뉴 표시기 */
.has-submenu > a:after {
    content: " ▾";
    font-size: 10px;
    vertical-align: 1px;
    margin-left: 4px;
    transition: transform 0.3s;
}

.has-submenu:hover > a:after {
    transform: rotate(180deg);
}

.has-submenu:hover .submenu {
    display: block;
    animation: fadeIn 0.3s ease-in-out;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(-10px); }
    to { opacity: 1; transform: translateY(0); }
}

.nav-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: 10px;
}

.nav-toggle span {
    display: block;
    width: 25px;
    height: 2px;
    background-color: var(--text-color);
    margin: 5px 0;
    transition: transform 0.3s, opacity 0.3s;
}

.nav-toggle.active span:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
}

.nav-toggle.active span:nth-child(2) {
    opacity: 0;
}

.nav-toggle.active span:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
}

@media screen and (max-width: 768px) {
    .nav-toggle {
        display: block;
        position: absolute;
        right: 20px;
        top: 10px;
    }

    nav .nav-content {
        flex-direction: column;
        align-items: flex-start;
    }

    nav .nav-menu {
        display: none;
        flex-direction: column;
        width: 100%;
    }

    nav .nav-menu.active {
        display: flex;
    }

    nav .nav-menu li {
        width: 100%;
    }

    nav a {
        padding: 15px 20px;
        border-top: 1px solid var(--hover-color);
        text-align: left;
    }

    /* 모바일 서브메뉴 */
    .submenu {
        position: static;
        box-shadow: none;
        display: none;
        background-color: var(--hover-color);
    }

    .has-submenu.active .submenu {
        display: block;
    }

    .submenu a {
        padding-left: 40px;
    }

    .has-submenu > a:after {
        float: right;
    }

    /* 모바일에서는 호버가 아닌 클릭으로 서브메뉴 열기 */
    .has-submenu:hover .submenu {
        display: none;
    }
}