:root {
    --flap-bg-color: #FFF;
    --flap-text-color: #222;
    --flap-border-color: #F5F5F5;
    --flap-font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolar, "Liberation Mono", "Courier New", monospace;;
    --flap-font-size: clamp(12px, 100cqh, 200px);
    --flap-font-weight: 500;
    --flap-line-height: 100cqh;
    --flap-letter-spacing: 0.02em;
}

*, *::before, *::after {
    box-sizing: border-box;
}

.split-flap-board {
    --cols: 10;
    --gap: clamp(0px, 1vmin, 0px);
    display: grid;
    grid-template-columns: repeat(var(--cols), minmax(0, 1fr));
    gap: var(--gap);
    align-items: stretch;
    padding-right: 1.5%;
}

.split-flap-cell {
    width: 100%;
    --flap-aspect: 38/50;
    aspect-ratio: var(--flap-aspect);
    display: block;
}

.split-flap {
    container-type: size;
    position: relative;
    display: grid;
    grid-template-rows: 1fr 1fr;
    width: 100%;
    height: 100%;
    border: 1px solid var(--flap-border-color);
    background-color: var(--flap-bg-color);
    overflow: hidden;
    perspective: 60cqh;
    border-radius: 0;

    box-shadow: 2px 2px  10px lightgray;
}

.split-flap.invisible {
    visibility: hidden;
}

.flap {
    position: relative;
    display: grid;
    place-items: center;
    color: var(--flap-text-color); /* Text Farbe */
    background-color: var(--flap-bg-color); /* Flap farb */
    width: 100%;
    height: 100%;
    overflow: hidden;
    transform-style: preserve-3d;
    transition: transform 0.2s cubic-bezier(0.3, 0, 0.8, 0.8);
}

.letter {
    display: block;
    font-size: var(--flap-font-size);
    line-height: var(--flap-line-height);
    font-family: var(--flap-font-family), sans-serif;
    font-weight: var(--flap-font-weight);
    letter-spacing: var(--flap-letter-spacing);
}

.top .letter {
    transform: translateY(-3%) rotateX(0deg);
}

.shadow .letter {
    transform: translateY(0%);
}

.bottom .letter {
    transform: translateY(-53%);
}

.top {
    transform-origin: bottom;
}

.bottom {
    transform-origin: top;
    border-top: 1px solid #222;
}

.shadow {
    position: absolute;
    inset: 0;
    z-index: 0;
    overflow: visible;
    pointer-events: none;
}

.notransition {
    transition: none !important;
}