html {
    background-color: black;
    overflow: hidden;
}

.wrapper {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    min-height: 100vh;
}

.wrapper button {
    user-select: none;
    width: 10%;
    height: 2em;
    outline: none;
    border: none;
    background-color: #302829;
    font-family: sans-serif;
    font-size: 1.5em;
    color: #CFCFCF;
    cursor: pointer;
    overflow: hidden;
    position: relative;
}

.wrapper button:after {
    content: "";
    background: #818181;
    display: block;
    position: absolute;
    padding-top: 300%;
    padding-left: 350%;
    margin-left: -20px !important;
    margin-top: -120%;
    opacity: 0;
    transition: all 0.8s;
}

.wrapper button:active:after {
    padding: 0;
    margin: 0;
    opacity: 1;
    transition: 0s;
}

.container {
    color: lime;
    display: flex;
    flex-direction: column;
}