catalog-ui/src/assets/preloading.css

html {
    height: 100%;
}
body {
    height: 100%;
    width: 100%;
    margin: 0px;
    padding: 0px;
    overflow:hidden;
}

.preloading-page {
    height: 100%;
    width: 100%;
    margin: 0px;
    overflow:hidden;
    background-image: linear-gradient(to bottom right, rgba(30, 36, 48, 1), rgba(59, 74, 93, 1));
    text-align: center;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-direction: column;
    color: #FFFFFF;
}

 .project-icon {
    width: 200px;
    height: 210px;
    margin-top: 0%;
    background-repeat: no-repeat;
}

.preloading-page-loading {
    font-size: 24px;
    line-height: 44px;
    font-family: Arial,  Helvetica, sans-serif;
    color: #1EB9F3;
    margin-top: 10%;
    margin-left: 3%;
}

.preloading-page-loading span {
    font-family: Arial, Helvetica, sans-serif;
    font-size: 50px;
    animation-name: blink;
    animation-duration: 1.5s;
    animation-iteration-count: infinite;
    animation-fill-mode: both;
}

.preloading-page-loading span:nth-child(2) {
    animation-delay: .5s;
}

.preloading-page-loading span:nth-child(3) {
    animation-delay: 1.0s;
}

@keyframes blink {
    0% {
        opacity: .2;
    }
    20% {
        opacity: 1;
    }
    100% {
        opacity: .2;
    }
}