style.css

body {
    margin: 0;
    padding: 0;
    font-size: 6em;
    font-weight: 800;
    font-family: 'Courier New', Courier, monospace;
}
.container {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    background: #2e2e2e;
    animation: change 1s forwards;
    animation-delay: 7.5s;
}
@keyframes change {
    0% {
        opacity: 1;
    }
    100% {
        opacity: 0;
    }
}
.box {
    height: 300px;
    width: 300px;
    border: 4px solid #3e3e3e;
    border-top: 5px solid #fff12c;
    border-right: 5px solid #fff12c;
    border-radius: 50%;
    z-index: 2;
    animation: rotate 4s linear infinite;
}
.rotater {
    position: relative;
    top: calc(50% - 2px);
    left: 50%;
    height: 4px;
    width: 50%;
    border: none;
    transform: rotate(45deg);
    transform-origin: left;
}
.circle {
    position: absolute;
    height: 30px;
    width: 30px;
    background: #fff12c;
    box-shadow: 0 0 10px #fff12c;
    border-radius: 50%;
    top: -11px;
    right: -15px;
}

@keyframes rotate {
    0% {
        transform: rotate(-135deg);
    }
    100% {
        transform: rotate(225deg);
    }
}
.cover {
    position: fixed;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 300px;
    width: 300px;
    color: #fff12c;
    border: 4px solid #3e3e3e;
    border-radius: 50%;
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.5);
    text-shadow: 0 0 20px #fff12c;
}
.welcome {
    position: fixed;
    top: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    width: 100vw;
    font-size: 2em;
    opacity: 0;
    animation: welcome 2s forwards;
    animation-delay: 7.8s;
}
@keyframes welcome {
    0% {
        opacity: 0;
    }
    100% {
        opacity: 1;
    }
}