Sticky & Flexible Fixed Right button

This an example of the problem of an flexible sticky button

by cintia_rodrigues

HTML

<a href="#" class="button">Conta sdsdsd s ct us lkjcvgf</a>

SCSS

body {
    background: #ededed;
}
a.button {
    background: #43515a url("http://www.aristaofrotorua.co.nz/rotorua-accommodation/images/email.jpg") no-repeat 88% center;
        font-family: "Myriad Pro";
        font-size: 17px;
        color: white;
        text-transform: uppercase;
        padding: 0 10px;
        outline: none;
        text-decoration: none;
        position: absolute; 
        top: 109px;
        right:0;
        /*width: 136px;*/
        height: 40px;
        line-height: 45px;
        -webkit-transform: rotate(-90deg);
        -moz-transform: rotate(-90deg);
        transform: rotate(-90deg);
    
     -webkit-transform-origin:100% 100%;
    -moz-transform-origin:100% 100%;
    transform-origin:100% 100%;
        
}