.shell {
    width: 60px;
    height: 500px;
    display: flex;
    top: 7vw;
    right: 0;
    position: absolute;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    background-color: rgb(17, 24, 39);
    border-radius: 5px;
    transition: 0.3s;
    overflow: hidden;
}

.box {
    display: block;
    height: 15%;
    width: 85%;
    margin: 9px;
    border-radius: 5px;
    transition: 0.3s;
    position: relative;
    color: rgb(160, 160, 175);
}

.box i {
    font-size: 20px;
    position: absolute;
    margin: 9px 0 0 21px;
}

.box:nth-child(1)::before,
.box:nth-child(5)::before {
    content: "";
    display: block;
    width: 100%;
    height: 2px;
    position: absolute;
    bottom: -9px;
    background-color: #9288aa;
}

.box span {
    position: relative;
    top: 11px;
    left: 50px;
    font: 250 10px '';
    opacity: 0;
    transition: 0.1s;
}

.shell:hover {
    width: 135px;
}

.box:hover {
    background-color: #374151;
    color: #fff;
}

.shell:hover span {
    opacity: 1;
}

.shell:nth-child(2) {
    background-color: #f3f4f6;
}

.shell:nth-child(2) .box{
    color: #000;
}
.shell:nth-child(2) .box:hover {
    background-color: #d1d5db;
    color: #f19f9f;
}

.shell:nth-child(3) {
    background-color: #312e81;
}

.shell:nth-child(3) .box{
    color: #6a6ac3;
}
.shell:nth-child(3) .box:hover {
    background-color: #4334ca;
    color: #aaaaf3;
}