“Cargando la barra CSS” Código de respuesta

Cargando la barra CSS

/*
	Simple mini-loading bar
    Working on: https://jsfiddle.net/alexlatorre/xe1tn9kh/1/
*/

<span class="loading"></span>

.loading {
    width: 250px;
    display: block;
    height: 2px;
    margin: 0px auto; 
    border-radius: 2px;
    background-color: #cfcfcf;
    position: relative;
    overflow: hidden;
    z-index: 1;
}
 .loading:before {
    content:'';
    height: 3px;
    width: 68px;
    position: absolute;
    -webkit-transform: translate(-34px, 0);
    -ms-transform: translate(-34px, 0);
    transform: translate(-34px, 0);
    background-color: #3b4a5e;
    border-radius: 2px;
    -webkit-animation: initial-loading 1.5s infinite ease;
    animation: animation 1.6s infinite ease;
}
@-webkit-keyframes animation {
    0% {
        left: 0
    }
    50% {
        left: 100%
    }
    100% {
        left: 0
    }
}

@keyframes animation {
    0% {
        left: 0
    }
    50% {
        left: 100%
    }
    100% {
        left: 0
    }
}