styles.css

* {
    padding: 0px;
    margin: 0px;
    box-sizing: border-box;
    font-family: Arial, sans-serif;
    font-size: x-large;
}

header {
    background-color: #262626;
}

a {
    color: #bdbdbd;
    text-decoration: none;
}

.navbar {
    min-height: 70px;
    display: flex;
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: 60px;
    padding: 0px 15px;
}

.nav-link:hover,
.dropdown:hover .dropbtn {
    color: rgb(255, 255, 255);
}

.nav-link {
    transition: 0.7s ease;
}

.up{
    display: none;
    color: #bdbdbd;
}

.drop-down .dropbtn {
    padding: 14px 16px;
}

.dropdown-content {
    position: absolute;
    left: 0px;
    right: 0px;
    max-height: 0;
    opacity: 0;
    background-color: #262626;
    min-width: 160px;
    z-index: 1;
    transition: max-height 0.7s ease, opacity 0.7s ease;
    padding: 20px;
    overflow: hidden;
}

.drop-down:hover .dropdown-content {
    max-height: 100vh;
    opacity: 1;
}

.dropdown-content a {
    float: none;
    color: #bdbdbd;
    padding: 12px 16px;
    text-decoration: none;
    display: block;
    text-align: left;
    transition: 0.7s ease;
}

.dropdown-content a:hover {
    color: #ffffff;
}

.hamburger, .down {
    display: none;
    cursor: pointer;
}

.bar {
    display: block;
    width: 25px;
    height: 3px;
    margin: 5px auto;
    transition: all 0.3s ease-in-out;
    background-color: white;
}

@media only screen and (max-width: 805px) {
    .navbar {
        flex-direction: column;
        align-items: left;
        justify-content: center;
    }

    .nav-menu {
        display: none;
        padding-top: 40px;
        flex-direction: column;
        gap: 0;
    }

    .nav-items {
        width: 100%;
        padding: 15px 0px;
        position: relative;
        text-align: left;
    }

    .nav-items:hover .up{
        position: absolute;
        display: block;
        color: inherit;
        top: 15px;
        right: 15px;
    }

    .nav-link {
        padding: 15px;
    }

    .dropdown-content {
        display: none;
        position: fixed;
        max-height: 100vh;
        top: 40px;
        flex-direction: column;
        gap: 0;
    }

    .down {
        display: none;
        color: #bdbdbd;
        position: absolute;
        top: 15px;
        left: 15px;
    }

    .dropdown-content.active, .down.active {
        display: block;
    }

    .dropdown-content.active {
        max-height: 100vh;
        opacity: 1;
    }

    .hamburger {
        display: block;
        position: fixed;
        right: 15px;
    }
    
    .hamburger.active {
        top: 15px;
    }

    .hamburger.active .bar:nth-child(1) {
        transform: rotate(-45deg) translate(-5px, 6px);
    }

    .hamburger.active .bar:nth-child(2) {
        opacity: 0;
    }

    .hamburger.active .bar:nth-child(3) {
        transform: rotate(45deg) translate(-5px, -6px);
    }

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