colouring-montreal/app/src/frontend/welcome.css

/**
 * Welcome jumbotron
 */
.welcome-float {
    position: absolute;
    z-index: 10000;
    top: 0;
    width: 100%;
    border-radius: 0;
    padding: 1.5em 2.5em 2.5em;
}
.welcome-float.jumbotron {
    background: #fff;
    background-color: rgba(255,255,255,0.95);
}
@media (min-width: 768px){
    .welcome-float {
        left: 50%;
        margin-left: -22.5em;
        width: 45em;
        top: 1em;
    }
}