JSFiddle - React, Tailwind, and code Playground

HTML

<div class="tank"></div>

CSS

.tank {
    position:relative;
    margin:50px;
    width:120px;
    height:180px;
    background-color:#444;
}
.tank:before {
    width: 120px;
    height: 50px;
    background-color:#666;
    -moz-border-radius: 60px / 25px;
    -webkit-border-radius: 60px / 25px;
    border-radius: 60px / 25px;
    position:absolute;
    content:'';
    top:-25px;
}
.tank:after {
    width: 120px;
    height: 50px;
    background-color:#444;
    -moz-border-radius: 60px / 25px;
    -webkit-border-radius: 60px / 25px;
    border-radius: 60px / 25px;
    position:absolute;
    content:'';
    top:155px;
    box-shadow:0px 0px 10px rgba(0, 0, 0, 0.75);
    z-index: -1;
}