JSFiddle - React, Tailwind, and code Playground

by Thiago Diniz

HTML

<div class="whatsapp">
    <i>Icon</i>
    <span>(41) 9233 - 4560</span>
</div>

CSS

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: sans-serif;
    transition: all .2s linear
}

.whatsapp {
    top: 100px;
    right: -150px; /* RIGHT NEGATIVO PARA ELE FICAR ESCONDIDO */
    padding: 15px 8px;
    color: #FFF;
    text-align: right;
    background-color: #21BA45;
    width: 200px;
    position: fixed;
    border-radius: 5px;
}

/* AQUI ZERA O RIGHT QUANDO O MOUSE ESTIVER EM CIMA DO ELEMENTO */
.whatsapp:hover {
    right: 0
}

.whatsapp i,
.whatsapp span {
    float: left
}

.whatsapp i {
    width: 20%;
    text-align: center;
    font-style: normal
}

.whatsapp span {
    width: 80%
}