exchange-2.0/resources/assets/sass/modules/_lock_screen.scss

/*------------------------------------------------------------------
[23. Lock Screen]
*/

.lock-container{
    margin-left: auto;
    margin-right: auto;
    width: 600px;
}

.lock-screen-wrapper {
    .credentials {
        margin-top: -84px;
        position: absolute;
        top: 50%;
        .thumbnail-wrapper {
            width: 53px;
            height: 53px;
        }
        .logged {
            opacity: .21;
            margin-top: -5px !important;
        }
        .name {
            opacity: .69;
            margin-top: -5px !important;
            font-size: 36px;
            height: 45px;
            overflow: hidden;
        }
    }
    .terms-wrapper {
        & > div {
            display: table;
        }
        .terms {
            display: table-cell;
            vertical-align: middle;
        }
        .logo-terms {
            width: 60px;
            height: 60px;
            border-radius: 15px;
            text-align: center;
            position: relative;
            .brand {
                left: 50%;
                margin-left: -21px;
                margin-top: -5px;
                position: absolute;
                top: 50%;
            }
        }
    }
}

/* Responsive Handlers : Lockscreen 
------------------------------------
*/
@media (max-width: 767px) {
    .lock-container{
        width: 80%;
    }
    .lock-screen-wrapper {
        .credentials {
            form {
                margin-top: 15px;
            }
        }
    }
}

@media (max-width: 480px) {

    .lock-screen-wrapper {
        .credentials {
            margin: 0;
            position: static;
            margin-top: 100px;
            width: 100%;
            float: left;
            clear: both;
            & > div {
                text-align: center;
            }
            .thumbnail-wrapper {
                float: none;
                margin: 0 auto;
            }
        }        
    }
}