style.css

#navbar {
    overflow: hidden;
    background-color: rgb(255, 254, 254);
}

.nav-content {
    overflow: hidden;
}

ul.nav-content li a {
    text-decoration: none;
    min-width: 30px;
    display: block;
    border-bottom: 1px solid gray;
    color: #373A36;
    font-family: 'Roboto', sans-serif;
}

ul.nav-content li a i {
    padding: 20px;
    color: rgb(135, 135, 135);
}

ul {
    list-style-type: none;
    border: 1px solid rgb(204, 204, 204);
    border-radius: 5px;
    width: 15%;
    padding-right: 10px;
}

ul li:last-child a {
    border-bottom: none;
}

.sub-menu-mob {
    list-style-type: none;
    border: 1px solid rgb(204, 204, 204);
    border-radius: 5px;
    width: 15%;
    position: absolute;
    padding-right: 10px;
    margin-left: 266px;
    margin-top: -57px;
    visibility: hidden;
    z-index: 1;
}

ul.sub-menu-mob li a {
    text-decoration: none;
    min-width: 30px;
    border-bottom: 1px solid gray;
    color: #373A36;
    padding: 20px;
    font-family: 'Roboto', sans-serif;
    float: left;
}

.nav-content li:first-child:hover .sub-menu-mob {
    visibility: visible;
}

.nav-content:hover .sub-menu-mob {
    display: block;
}

.sub-menu-mob a:hover {
    display: block;
}

.sub-menu-tech {
    list-style-type: none;
    border: 1px solid rgb(204, 204, 204);
    border-radius: 5px;
    width: 15%;
    position: absolute;
    padding-right: 10px;
    margin-left: 266px;
    margin-top: -57px;
    visibility: hidden;
    z-index: 1;
}


ul.sub-menu-tech li a {
    text-decoration: none;
    min-width: 30px;
    border-bottom: 1px solid gray;
    color: #373A36;
    padding: 20px;
    font-family: 'Roboto', sans-serif;
    float: left;
}

ul[class*="menu"] li{
    display: flex;
    flex-direction: column;
}

ul[class*="menu"] li:last-child a {
    border-bottom: none;
}

.nav-content li:nth-child(2):hover .sub-menu-tech {
    visibility: visible;
}

.nav-content:hover .sub-menu-tech {
    display: block;
}

.sub-menu-tech a:hover {
    display: block;
}