.c4d4u-puzzle {
    --c4d4u-max-width: 920px;
    width: 100%;
    max-width: var(--c4d4u-max-width);
    margin: 1rem auto;
    box-sizing: border-box;
    font-family: inherit;
}

.c4d4u-puzzle-caption {
    margin: 0 0 .7rem;
    font-size: 1.05rem;
    font-weight: 600;
    line-height: 1.35;
    text-align: center;
}

.c4d4u-puzzle-board {
    width: 100%;
    padding: clamp(8px, 1.4vw, 18px);
    box-sizing: border-box;
    overflow: visible;
    border: 1px solid rgba(0, 0, 0, .12);
    border-radius: 12px;
    background: #f7f7f7;
    box-shadow: 0 1px 5px rgba(0, 0, 0, .08);
}

.c4d4u-puzzle-svg {
    display: block;
    width: 100%;
    height: auto;
    overflow: visible;
    max-height: 72vh;
    margin: 0 auto;
}

.c4d4u-board-bg {
    fill: #ffffff;
}

.c4d4u-cell {
    fill: var(--c4d4u-piece-color);
    stroke: none;
    stroke-opacity: 0;
    stroke-width: 0;
    vector-effect: non-scaling-stroke;
    transition: fill .16s ease, stroke .16s ease;
}

.c4d4u-puzzle[data-view="black-white"] .c4d4u-cell {
    fill: #ffffff;
    stroke: #b7b7b7;
    stroke-opacity: 1;
    stroke-width: .8;
}

.c4d4u-cell-number {
    opacity: 0;
    fill: #000000;
    stroke: none;
    stroke-width: 0;
    paint-order: normal;
    font-family: Arial, Helvetica, sans-serif;
    font-size: 17px;
    font-weight: 700;
    pointer-events: none;
    user-select: none;
    transition: opacity .14s ease;
}

.c4d4u-puzzle.c4d4u-numbers-visible .c4d4u-cell-number {
    opacity: 1;
}

.c4d4u-coordinate-labels {
    opacity: 0;
    pointer-events: none;
    transition: opacity .14s ease;
}

.c4d4u-puzzle.c4d4u-coordinates-visible .c4d4u-coordinate-labels {
    opacity: 1;
}

.c4d4u-coordinate-label {
    fill: #202020;
    stroke: none;
    stroke-width: 0;
    paint-order: normal;
    font-family: Arial, Helvetica, sans-serif;
    font-size: 17px;
    font-weight: 700;
    user-select: none;
}

.c4d4u-coordinate-column {
    dominant-baseline: auto;
}


.c4d4u-puzzle[data-view="extreme"] .c4d4u-cell {
    fill: var(--c4d4u-extreme-color);
}

.c4d4u-piece-border {
    fill: none;
    stroke: transparent;
    stroke-width: 0;
    stroke-linecap: square;
    stroke-linejoin: miter;
    vector-effect: non-scaling-stroke;
    pointer-events: none;
    transition: stroke-width .16s ease, stroke .16s ease;
}


.c4d4u-puzzle[data-view="black-white"] .c4d4u-piece-border {
    stroke: #242424;
    stroke-width: 1.45;
}

.c4d4u-board-frame {
    fill: none;
    stroke: #202020;
    stroke-width: 1.7;
    vector-effect: non-scaling-stroke;
    pointer-events: none;
}

.c4d4u-puzzle.c4d4u-solution-visible .c4d4u-solution-cell {
    stroke: #000000;
    stroke-opacity: 1;
    stroke-width: 1.25;
}

.c4d4u-puzzle.c4d4u-solution-visible .c4d4u-solution-border {
    stroke: #000000;
    stroke-width: 4.25;
    stroke-opacity: 1;
}

.c4d4u-puzzle-controls {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: .65rem 1rem;
    margin-top: .85rem;
}

.c4d4u-puzzle-view-buttons,
.c4d4u-puzzle-option-buttons {
    display: inline-flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: .4rem;
}

.c4d4u-puzzle button {
    appearance: none;
    border: 1px solid rgba(0, 0, 0, .28);
    border-radius: 7px;
    background: #ffffff;
    color: #202020;
    padding: .55rem .85rem;
    font: inherit;
    line-height: 1.2;
    cursor: pointer;
    transition: background .14s ease, border-color .14s ease, transform .05s ease;
}

.c4d4u-puzzle button:hover {
    background: #f1f1f1;
    border-color: rgba(0, 0, 0, .48);
}

.c4d4u-puzzle button:active {
    transform: translateY(1px);
}

.c4d4u-puzzle button[aria-pressed="true"] {
    background: #202020;
    border-color: #202020;
    color: #ffffff;
}

.c4d4u-solution-button {
    min-width: 132px;
}

.c4d4u-mode-preview {
    --c4d4u-max-width: 420px;
}

.c4d4u-mode-preview .c4d4u-puzzle-board {
    padding: 8px;
    border-radius: 8px;
    box-shadow: none;
}

.c4d4u-puzzle-error {
    box-sizing: border-box;
    max-width: 920px;
    margin: 1rem auto;
    padding: .8rem 1rem;
    border-left: 4px solid #b32d2e;
    background: #fff3f3;
}

.c4d4u-puzzle-debug {
    margin-top: 1rem;
    padding: .65rem .8rem;
    background: #fafafa;
    border: 1px solid #ddd;
}

.c4d4u-puzzle-debug pre {
    white-space: pre-wrap;
    overflow-wrap: anywhere;
}


.c4d4u-print-controls {
    display: inline-flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: .4rem;
    padding-left: .35rem;
    border-left: 1px solid rgba(0, 0, 0, .14);
}

.c4d4u-print-controls select {
    min-height: 38px;
    border: 1px solid rgba(0, 0, 0, .24);
    border-radius: 7px;
    background: #ffffff;
    color: #202020;
    padding: .35rem .55rem;
    font: inherit;
}

.c4d4u-print-button {
    font-weight: 600 !important;
}

@media (max-width: 600px) {
    .c4d4u-puzzle {
        margin: .7rem auto;
    }

    .c4d4u-puzzle-board {
        padding: 7px;
        border-radius: 8px;
    }


    .c4d4u-cell-number,
    .c4d4u-coordinate-label {
        font-size: 15px;
    }

    .c4d4u-puzzle-controls {
        gap: .45rem;
    }

    .c4d4u-puzzle button {
        padding: .5rem .65rem;
        font-size: .94rem;
    }
}