triangle bouton method translate

HTML

<div class="outer-mylink">
    <a class='mylink'><i>-</i></a>
</div>

CSS

body{
     margin: 100px 0 0 ;
}

a, .mylink i {
    cursor: pointer;
    -webkit-transition: all .3s ease;
    -moz-transition: all .3s ease;
    -o-transition: all .3s ease;
    transition: all .3s ease;
}
.outer-mylink {
    width:100%;
    height: 71px;
    background: gray;
    overflow: hidden;
    position: relative;
    text-align: center;
}
.mylink, .mylink i {
    display: block;
}
.mylink {
    width: 100px;
    height: 100px;
    -moz-transform: rotate(45deg) translate(-35px, -35px);
    -o-transform: rotate(45deg) translate(-35px, -35px);
    -webkit-transform: rotate(45deg) translate(-35px, -35px);
    transform: rotate(45deg) translate(-35px, -35px);
    margin: 0 auto;
    background: red;
    position:relative;
}

/* si icone fixe */
/*
.mylink i {
    width: 32px;
    height: 32px;
    font-size: 32px;
    font-style: normal;
    line-height: 32px;
    color: white;
    transform: rotate(-45deg) translate(0px, 80px);
    -ms-transform: rotate(-45deg) translate(0px, 80px);
    -webkit-transform: rotate(-45deg) translate(0px, 80px);
    -o-transform: rotate(-45deg) translate(0px, 80px);
    background: gray;
}
*/

/* si effet hover sur icone */
.mylink i {
    width: 32px;
    height: 32px;
    font-size: 32px;
    font-style: normal;
    line-height: 32px;
    color: white;
    position:absolute;
    top: 55px;
    left: 55px;
    
    transform: rotate(-45deg);
    -ms-transform: rotate(-45deg);
    -webkit-transform: rotate(-45deg);
    -o-transform: rotate(-45deg);
    background: gray;
}


.mylink:hover {
    background: blue;
}

.mylink:hover i {
    transform: rotate(0deg);
    -ms-transform: rotate(0deg);
    -webkit-transform: rotate(0deg);
    -o-transform: rotate(0deg);    
}