style.css

html {
    /*color: white;*/
    /*background-color: rgb(50, 50, 50);*/
    font-family: Source Sans Pro,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica Neue,Arial,Noto Sans,sans-serif,Apple Color Emoji,Segoe UI Emoji,Segoe UI Symbol,Noto Color Emoji;
    line-height: 1.5;
}

body {
    display: flex;
    align-items: center;
    flex-direction: column;
}

button {
    width: 100%;
    height: 40px;
    margin-top: 20px;
    cursor: pointer;
    background: none;
    border: 2px solid black;
    /*color: white;*/
    transition: all 0.2s ease;
}

button:hover {
    border: 2px solid gray;
    color: gray;
    transition: all 0.2s ease;
}

.graphs {
    margin: 20px;
}

.graphs > div {
    margin: 20px;
}

.lds-ripple {
    display: inline-block;
    position: relative;
    width: 80px;
    height: 80px;
}
.lds-ripple div {
    position: absolute;
    border: 4px solid #000;
    opacity: 1;
    border-radius: 50%;
    animation: lds-ripple 1s cubic-bezier(0, 0.2, 0.8, 1) infinite;
}
.lds-ripple div:nth-child(2) {
    animation-delay: -0.5s;
}
@keyframes lds-ripple {
    0% {
        top: 36px;
        left: 36px;
        width: 0;
        height: 0;
        opacity: 0;
    }
    4.9% {
        top: 36px;
        left: 36px;
        width: 0;
        height: 0;
        opacity: 0;
    }
    5% {
        top: 36px;
        left: 36px;
        width: 0;
        height: 0;
        opacity: 1;
    }
    100% {
        top: 0px;
        left: 0px;
        width: 72px;
        height: 72px;
        opacity: 0;
    }
}