style.css

* {
    padding: 0;
    margin: 0;
}

html {
    overflow: hidden;
    font-family: sans-serif;
}

canvas {

}

.reset {
    position: fixed;
    z-index: 5;
    left: calc(50% - 33px);
    bottom: 20px;
    appearance: none;
    border: 0;
    background-color: transparent;
    filter: drop-shadow(0 15px 12px rgba(0,0,0,0.5));
    cursor: pointer;
}
.reset:active,
.reset:focus,
.reset:hover {
    outline: none;
    border: 0;
}

.reset:hover svg {
    animation: rotate ease 0.5s;
}

#start {
    position: fixed;
    z-index: 10;
    left: calc(50% - 50px);
    top: calc(50% - 50px);
    appearance: none;
    border: 0;
    background: transparent;
    filter: drop-shadow(0 15px 12px rgba(0,0,0,0.5));
    cursor: pointer;
    display: none;
}
#start:active,
#start:focus,
#start:hover {
    outline: none;
    border: 0;
}
#start:hover svg {
    animation: scale ease 0.5s;
}

.kmh {
    position: fixed;
    z-index: 5;
    right: 20px;
    bottom: 20px;
    font-size: 1vw;
    color: #fff;
}
.kmh strong {
    font-size: 3vw;
}

@keyframes scale {
    0%,100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.1);
    }
}
@keyframes rotate {
    0% {
        transform: rotate(0deg);
    }
    100% {
        transform: rotate(360deg);
    }
}