earth.css

html, body {
    margin: 0;
    padding: 0;
    border: 0;
    overflow: hidden;
    /*background-image: url("images/Nebula-10898.jpg");*/
}

.score {
    padding: 15px;
    width: 300px;
    height: 65px;
    opacity: 0.6;
    background-color: black;
    position: absolute;
    top: 0; bottom: 0; left: 0; right: 0;
    z-index: 1;
    margin: 50px auto;
    color: white;
    font-size: 24px;
}

.score table {
    opacity: 1;
    background: rgba(0,0,0,0.4);
}

.score .deviation-sum {
    text-align: center;
    font-size: 36px;
}

#playground {
    width: 1000px;
    height: 1000px;
    /*background-color: #00A6C7;*/
    position: absolute;
    top: 0; bottom: 0; left: 0; right: 0;
    margin: auto;
}

.block {
    vertical-align: top;
    width: 25px;
    height: 25px;
    /*background-color: grey;*/
    display: inline-block;
    margin: 0;
    background-size: contain;
}

.block:hover {
    background-image: url("images/ground/plus-brick.png");
    cursor: pointer;
}

.block.block-ground:hover {
    background-image: url("images/ground/cross-brick.png");
}


.block.block-ground:active {
    /*background-color: red;*/
}

.block.block-ground {
    /*background-color: saddlebrown;*/
    background-image: url("images/ground/brick.png");
    /*background-image: url("images/ground/stone-clipart-transparent-13.png");*/

}
.block.block-surface {
    /*background-color: yellow;*/
}
.arrow {
    position: absolute;
    overflow: hidden;
    pointer-events: none;
    width: 10px;
    transform-origin: top;
}

.arrow img {
    pointer-events: none;
    position: absolute;
    bottom: 0;
    width: 10px;
}

.universe-image {
    z-index: -1000;
    position: absolute;
    top: 80%;
    left: 50%;
    /*margin:-960px 0 0 -1280px;*/
    -webkit-animation:spin 4s linear infinite;
    -moz-animation:spin 4s linear infinite;
    animation:spin 350s linear infinite;
}
@-moz-keyframes spin { 100% { -moz-transform: rotate(360deg); } }
@-webkit-keyframes spin { 100% { -webkit-transform: rotate(360deg); } }
@keyframes spin { 100% { -webkit-transform: rotate(360deg); transform:rotate(360deg); } }