teTra/css/style.css

body {
    margin: 0;
    padding: 0;
    background-color: #222;
    font-family: -apple-system, "Segoe UI", Roboto, "Helvetica Neue",
        "Noto Sans", "Liberation Sans", Arial, sans-serif, "Apple Color Emoji",
        "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji";
}

span {
    position: absolute;
}

.lil-gui {
    --background-color: rgba(33, 37, 41, 30%);
    --width: 200px;
}
@supports (backdrop-filter: blur()) {
    .lil-gui {
        backdrop-filter: blur(15px);
    }
}

.lil-gui.autoPlace {
    top: inherit;
    bottom: 15px;
    left: 15px;
}

.lil-gui.root > .title {
    font-size: 1.5em;
}

.lil-gui .controller.disabled {
    opacity: .8;
}

canvas {
    cursor: grab;
}

#messagesSpan {
    position: absolute;
    top: 10%;
    left: 50%;
    width: 50%;
    transform: translate(-50%, 0);
    color: rgba(255, 255, 255, 0.8);
    font-weight: 400;
    line-height: 1.5;
    font-size: 3vmin;
    text-align: center;
}

#messagesSpan div {
    opacity: 0;
    overflow: hidden;
    user-select: none;
}

h1 {
    font-size: calc(1.375rem + 1.5vw);
}

@keyframes show-level-animation {
    from {
        opacity: 0;
        transform: translateY(200%);
    }
    50% {
        opacity: 100%;
        transform: translateY(0) scaleY(1);
        line-height: var(--bs-body-line-height);
    }
    to {
        opacity: 0;
        transform: translateY(-100%) scaleY(0);
        line-height: 0;
    }
}

#messagesSpan div.show-level-animation {
    animation: show-level-animation;
    animation-timing-function: (0.4, 0, 0.6, 1);
    animation-duration: 2s;
}

@keyframes zoom-in-animation {
    from {
        opacity: 0;
        transform: scale3d(0.3, 0.3, 0.3);
        line-height: var(--bs-body-line-height);

    }
    30% {
        opacity: 1;
        transform: scale3d(1, 1, 1);
    }
    80% {
        opacity: 1;
        transform: scale3d(1, 1, 1);
        line-height: var(--bs-body-line-height);
    }
    to {
        opacity: 0;
        transform: scale3d(1.5, 0, 1);
        line-height: 0;
    }
}

@keyframes rotate-in-animation {
    0% {
        opacity:0;
        transform:rotate(200deg);
        line-height: var(--bs-body-line-height);
    }
    30% {
        opacity:1;
        transform:translateZ(0);
        transform: scale3d(1, 1, 1);
    }
    80% {
        opacity: 1;
        transform: scale3d(1, 1, 1);
        line-height: var(--bs-body-line-height);
    }
    to {
        opacity: 0;
        transform: scale3d(1.5, 0, 1);
        line-height: 0;
    }
}

#messagesSpan div.rotate-in-animation {
    animation-name:  rotate-in-animation;
    animation-timing-function: cubic-bezier(.25,.46,.45,.94);
    animation-duration: 1s;
}

#messagesSpan div.zoom-in-animation {
    animation-name: zoom-in-animation;
    animation-timing-function: cubic-bezier(.25,.46,.45,.94);
    transform-origin:center;
    animation-duration: 1s;
}

@keyframes game-over-animation {
    from {
        opacity: 0;
        transform: translateY(200%);
    }
    to {
        opacity: 100%;
        transform: translateY(0) scaleY(1);
        line-height: var(--bs-body-line-height);
    }
}

#messagesSpan div.game-over-animation {
    animation: game-over-animation;
    animation-timing-function: (0.4, 0, 0.6, 1);
    animation-duration: 2s;
}

.pause canvas {
    filter: blur(10px);
}

#pauseSpan {
    display: none;
}

.pause #pauseSpan {
    display: flex;
    position:absolute;
    top: 0;
    left: 0;
    filter: blur(2px);
    width: 100%;
    height: 100%;
    z-index: 10;
    color: rgba(255, 255, 255, 20%);
    justify-content: center;
    align-items: center;
    font-size: 20vh;
    font-weight: 800;
    letter-spacing: .1em;
    user-select: none;
}