@font-face {
    font-family: 'Liberation Serif';
    src: url(../fonts/liberation-serif-regular.woff2);
}

@font-face {
    font-family: 'Liberation Serif';
    src: url(../fonts/liberation-serif-bold.woff2);
    font-weight: bold;
}

:root {
    --color0: #dcdcdc;
    --color1: #e23838;
    --color2: #5ebd3e;
    --color3: #f78200;
    --color4: #009cdf;
    --color5: #ffb900;
    --color6: #973999;
    --offset: 2px;
    --board-size: 8;
    --board-height: 97vmax;
    --board-width: 97vmin;
    --notch-outer-size: 10px;
    --notch-inner-size: 9px;
    --hole-code-size: 1.5;
    --hole-clue-size: 3.9;
    --outer: polygon(
                0% var(--notch-outer-size), 
                var(--notch-outer-size) 0%, 
                calc(100% - var(--notch-outer-size)) 0%, 
                100% var(--notch-outer-size), 
                100% calc(100% - var(--notch-outer-size)), 
                calc(100% - var(--notch-outer-size)) 100%, 
                var(--notch-outer-size) 100%, 
                0% calc(100% - var(--notch-outer-size))
             );
    --inner: polygon(
                0% var(--notch-inner-size), 
                var(--notch-inner-size) 0%, 
                calc(100% - var(--notch-inner-size)) 0%, 
                100% var(--notch-inner-size), 
                100% calc(100% - var(--notch-inner-size)), 
                calc(100% - var(--notch-inner-size)) 100%, 
                var(--notch-inner-size) 100%, 
                0% calc(100% - var(--notch-inner-size))
             );
    --section-height: calc(var(--board-height) / var(--board-size) - var(--offset) * 2 + var(--offset));
    --hole-size: calc((var(--section-height)) / var(--hole-code-size));
}

body {
    font-family: 'Liberation Serif', serif;
    background-color: white;
    overflow: hidden;
    cursor: default;
    margin: 0;
    position: absolute;
    top: 50%;
    left: 50%;
    margin-right: -50%;
    transform: translate(-50%, -50%);
}

.board {
    display: flex;
    flex-direction: column;
    width: var( --board-width);
    height: calc(var(--board-height) - (var(--board-size) - 2) * var(--offset));
    margin: auto;
}

.row {
    display: flex;
    margin-bottom: calc(var(--offset) * -1);
    margin-left: calc(var(--offset) / 2);
    opacity: 0;
}

.code-outer {
    width: calc(var(--board-width) / 4 * 3);
    height: calc(var(--board-height) / var(--board-size) + var(--offset));
    background-color: black;
    clip-path: var(--outer);
}

.code-inner {
    display: flex;
    position: relative;
    align-items: center;
    justify-content: space-evenly;
    background-color: white;
    width: calc(var(--board-width) / 4 * 3 - var(--offset) * 2);
    height: var(--section-height);
    left: var(--offset);
    top: var(--offset);
    clip-path: var(--inner);
}

.hole-code {
    height: var(--hole-size);
    width: var(--hole-size);
    background-color: var(--color0);
    border-radius: 50%;
}

.row:not(:first-child) .hole-code:not(.occupied) {
    cursor: pointer;
}

.clue-outer {
    width: calc(var(--board-width) / 4);
    height: calc(var(--board-height) / var(--board-size) + var(--offset));
    background-color: black;
    margin-left: calc(var(--offset) * -1);
    clip-path: var(--outer);
}

.clue-inner {
    display: grid;
    position: relative;
    grid-template-columns: auto auto;
    place-items: center;
    width: calc(var(--board-width) / 4 - var(--offset) * 2);
    height: var(--section-height);
    gap: 5px;
    background-color: white;
    left: var(--offset);
    top: var(--offset);
    clip-path: var(--inner);
}

.hole-clue {
    box-sizing: border-box;
    height: calc((var(--section-height)) / var(--hole-clue-size));
    width: calc((var(--section-height)) / var(--hole-clue-size));
    background-color: var(--color0);
    border-radius: 50%;
}

.flip-container {
    width: calc(var(--board-width) / 4 * 3 - var(--offset) * 2);
    height: var(--section-height);
    background-color: transparent;
    perspective: 1000px;
}

.flip-container.flip .flipper {
    transform: rotateX(180deg);
}

.flipper {
    position: relative;
    width: 100%;
    height: 100%;
    text-align: center;
    transition: transform 0.6s;
    transform-style: preserve-3d;
}

.front, .back {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    -webkit-backface-visibility: hidden;
  }

.front {
    display: grid;
    place-content: center;
}

.back {
    transform: rotateX(180deg);
}

#title {
    font-size: 12.2vmin;
    font-weight: bold;
    margin: 0;
    margin-top: -2vmin;
}

#subtitle {
    font-size: 3vmin;
    margin-top: -0.7em;
    margin-bottom: -0.3em;
    color: gray;
}

#solution {
    display: flex;
    align-items: center;
    justify-content: space-evenly;
    width: calc(var(--board-width) / 4 * 3 - var(--offset) * 2);
    height: var(--section-height);
}

.row.header .clue-inner {
    grid-template-columns: none;
}

.button {
    height: var(--hole-size);
    width: var(--hole-size);
    margin-left: calc((var(--board-width) / 4 - var(--offset) * 2) / -50);
    opacity: 0.137;
}

.pegs {
    display: flex;
    align-items: flex-end;
    justify-content: space-evenly;
    width: calc(var(--board-width));
    height: calc(var(--board-height) / var(--board-size) - 10px);
}

.peg {
    height: var(--hole-size);
    width: var(--hole-size);
    border-radius: 50%;
    opacity: 0;
}

[data-color="1"] {
    background-color: var(--color1) !important;
}

[data-color="2"] {
    background-color: var(--color2) !important;
}

[data-color="3"] {
    background-color: var(--color3) !important;
}

[data-color="4"] {
    background-color: var(--color4) !important;
}

[data-color="5"] {
    background-color: var(--color5) !important;
}

[data-color="6"] {
    background-color: var(--color6) !important;
}

.black {
    background-color: black;
}

.white {
    background-color: white;
    border: 1px solid black;
}

.move {
    z-index: 100;
    transition: transform 0.3s ease-in-out;
}

.visible {
    opacity: 1;
}

.enabled {
    cursor: pointer;
}

.enabled .button {
    opacity: 1;
}

.selected {
    opacity: 0.4;
}

.rotate {
    display: none;
    width: 50vmin;
    height: 50vmin;
    margin: auto;
}

.rotate img {
    width: 100%;
    height: 100%;
}

.blink {
    animation: blink 0.1s ease-in-out forwards;
}

@keyframes blink {
    
    0% {
        opacity: 1; 
    }
  
    50% {
        opacity: 0.5;
    } 

    100% {
        opacity: 1; 
    } 
}

@media (prefers-color-scheme: dark) {

    body {
        background-color: black;
    }

    #title {
        color: whitesmoke;
    }
    
    #subtitle {
        color: lightgray;
    }

    .button {
        filter: invert(100%);
        opacity: 0.412;
    }

    .enabled .button {
        opacity: 0.961;
    }

    .code-outer, .clue-outer {
        background-color: whitesmoke;
    }

    .code-inner, .clue-inner {
        background-color: black;
    }

    .hole-code, .hole-clue {
        background-color: dimgray;
    }

    .white {
        background: whitesmoke;
    }
    
    .black {
        background: black;
        border: 1px solid whitesmoke;
    }

    .selected {
        opacity: 0.6;
    }

    .rotate {
        filter: invert(100%);
        opacity: 0.961;
    }

    @keyframes blink {

        0% {
            opacity: 0.961; 
        }
    
        50% {
            opacity: 0.412;
        } 

        100% {
            opacity: 0.961; 
        } 
    }
}

@media (min-width: 460px) and (min-height: 460px) {

    :root {
        --notch-outer-size: 15px;
        --notch-inner-size: 13px;
        --offset: 3px;
    }

    #title {
        font-size: calc(var(--board-width) / 4 * 3 / 6.2);
    }
    
    #subtitle {
        font-size: 2vmin;
    }
}

@media (min-width: 1200px), (min-height: 1200px) {

    :root {
        --notch-outer-size: 20px;
        --notch-inner-size: 18px;
    }
}

@media (hover: hover) {

    :root {
        --notch-outer-size: 10px;
        --notch-inner-size: 8px;
    }

    #title {
        font-size: calc(var(--board-width) / 4 * 3 / 6);

    }
    
    #subtitle {
        font-size: calc(var(--board-height) / 68);
    }
}

@media (orientation: landscape) and ((hover: none) or (pointer: coarse)) {

    .board {
        display: none;
    }

    .rotate {
        display: block;
    }
}

.noselect {
    -webkit-tap-highlight-color: transparent;
          -webkit-touch-callout: none;
            -webkit-user-select: none;
               -moz-user-select: none;
                -ms-user-select: none;
                    user-select: none;
}