Custom file input

application.css

.file_upload {
    position: relative;
    overflow: hidden;
    float: left;
    margin-right: 4px;
}
.file_upload input {
    position: absolute;
    top: 0;
    right: 0;
    margin: 0;
    opacity: 0;
    filter: alpha(opacity=0);
    transform: translate(-300px, 0) scale(4);
    font-size: 23px;
    direction: ltr;
    cursor: pointer;
}