html {
    font-size: 20px;
    margin: 0;
    background: #0c0207;
}
#frame {
    width: 1325px;
    height: 500px;
    margin: 0 auto;
    overflow: hidden;
    border-radius: 16px;
    margin-top: 2em;
}

#sky {
    border-radius: 16px;
    width: 1325px;
    height: 500px;
    background: linear-gradient(to bottom, #0B4C5F 0%, #0c0207 100%);
    position: absolute;
    z-index: -30;
    top: 0;
    margin-top: 2em;
}

#buildings {
    background: url('assets/buildings.svg');
    height: 500px;
    width: 1325px;
    z-index: -10;
    top: 6.5em;
    background-position: 0px 0px;
    background-repeat: repeat-x;
    -webkit-animation: animation_buildings 120s linear infinite;
    -ms-animation: animation_buildings 120s linear infinite;
    -moz-animation: animation_buildings 120s linear infinite;
    position: absolute;
    }

/* Animation buildings */

    @keyframes animation_buildings {
        from { background-position: 0 0; }
        to { background-position: 100% 0; }
    }
    @-webkit-keyframes animation_buildings {
        from { background-position: 0 0; }
        to { background-position: 100% 0; }
    }
    @-ms-keyframes  animation_buildings {
        from { background-position: 0 0; }
        to { background-position: 100% 0; }
    }
    @-moz-keyframes  animation_buildings {
        from { background-position: 0 0; }
        to { background-position: 100% 0; }
    }

#moon {
    width: 6em;
    height: 6em;
    -moz-border-radius: 50%;
    -webkit-border-radius: 50%;
    border-radius: 50%;
    -moz-box-shadow: 30px 10px 0 #F7F8E0;
    -webkit-box-shadow: 30px 10px 0 #F7F8E0;
    box-shadow: 30px 10px 0 #F7F8E0;
    margin-top: 1em;
    margin-left: 50%;
    position: absolute;
    z-index: -19;
}

#wall {
    height: 23em;
    width: 100%;
    background: -moz-linear-gradient(top, #416663 0%, #0c0207 19%);
    background: -webkit-linear-gradient(top, #416663 0%, #0c0207 19%);
    background: linear-gradient(to bottom, #416663 0%, #0c0207 19%);
    bottom: 0px;
}

#cat {
    background: url('assets/cat.svg');
    height: 297px;
    width: 507.5px;
    margin-top: 2em;
    margin-left: 2em;
    z-index: 10;
    -webkit-animationn: sprite-animation 1.2s steps(16, end) infinite;
    -moz-animation: sprite-animation 1.2s steps(16, end) infinite;
    -ms-animation:sprite-animation 1.2s steps(16, end) infinite;
    animation: sprite-animation 1.2s steps(16, end) infinite;
    }

@-webkit-keyframes sprite-animation {
        from { background-position: 0 0; }
        to { background-position: -8120px 0; }
    }

@-ms-keyframes sprite-animation { 
        from { background-position: 0 0; }
        to { background-position: -8120px 0; }
    } 

@-moz-keyframes sprite-animation { 
        from { background-position: 0 0; }
        to { background-position: -8120px 0; }
    }
    
@keyframes sprite-animation { 
        from { background-position: 0 0; }
        to { background-position: -8120px 0; }
    }