html, body, app-root {
    width: 100%;
    height: 100%;
    margin: 0;
    padding: 0;
}

body {
    background: aliceblue url('https://ast.poemschina.com/assets/bg/0.jpg') no-repeat center/cover;
}

.logo {
    position: absolute;
    margin: 0 auto;
    top: 50%;
    margin-top: -165px;
    height: 80px;
    left: 0;
    right: 0;
    text-align: center;
}

    .logo img {
        width: 80px;
    }

.txt {
    color: white;
    text-transform: uppercase;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen-Sans, Ubuntu, Cantarell, Helvetica, sans-serif;
    font-size: 1.5em;
    text-shadow: 2px 2px 10px rgba(0,0,0,0.2);
    padding-top: 75px;
}

.bottom {
    color: white;
    position: absolute;
    text-align: center;
    width: 100%;
    font-size: 16px;
    bottom: 10px;
}

.loading i {
    margin: auto;
    position: absolute;
    top: calc(50% - 60px);
    left: calc(50% - 20px);
    width: 40px;
    height: 40px;
    display: block;
    animation: loading 60s infinite;
}

.loading span {
    position: absolute;
    width: 100%;
    height: 100%;
    opacity: 0;
    animation: i 5s infinite;
}

    .loading span:after {
        content: '';
        display: block;
        position: absolute;
        left: 0px;
        top: 0px;
        width: 5px;
        height: 5px;
        background: rgba(255, 255, 255, 0.7);
        border-radius: 5px;
    }

    .loading span:nth-child(1) {
        animation-delay: 0.2s;
    }

    .loading span:nth-child(2) {
        animation-delay: 0.4s;
    }

    .loading span:nth-child(3) {
        animation-delay: 0.6s;
    }

    .loading span:nth-child(4) {
        animation-delay: 0.8s;
    }

    .loading span:nth-child(5) {
        animation-delay: 1s;
    }

@media (min-width:992px) {
    .txt {
        font-size: 2em;
        padding-top: 100px;
    }

    .logo img {
        width: 100px;
    }

    .logo {
        margin-top: -200px;
        height: 100px;
    }

    .loading i {
        margin: auto;
        position: absolute;
        top: calc(50% - 70px);
        left: calc(50% - 25px);
        width: 50px;
        height: 50px;
        display: block;
        animation: loading 60s infinite;
    }
}

@keyframes loading {
    form {
        transform: rotate(0deg);
    }

    to {
        transform: rotate(360deg);
    }
}

@keyframes i {
    0% {
        opacity: 1;
        transform: rotate(180deg);
        animation-timing-function: ease-out;
    }

    7% {
        opacity: 1;
        transform: rotate(300deg);
        animation-timing-function: linear;
    }

    30% {
        opacity: 1;
        transform: rotate(410deg);
        animation-timing-function: ease-in-out;
    }

    39% {
        opacity: 1;
        transform: rotate(645deg);
        animation-timing-function: linear;
    }

    70% {
        opacity: 1;
        transform: rotate(770deg);
        animation-timing-function: ease-out;
    }

    75% {
        opacity: 1;
        transform: rotate(900deg);
        animation-timing-function: ease-out;
    }

    76% {
        opacity: 0;
        transform: rotate(900deg);
    }

    100% {
        opacity: 0;
        transform: rotate(900deg);
    }
}