:root {
    --grid-unit: 14.4pt;
    --grid-size: calc(var(--grid-unit) * 4);
}

.board {
    margin: 12px 0 24px 0;
    width: 100%;
    max-width: 100%;
    min-height: 520px;
    border-radius: 8px;
    overflow-x: auto;
    overflow-y: hidden;
    -webkit-overflow-scrolling: touch;
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.12);
    transition: background 0.25s ease, color 0.25s ease;
    background-clip: padding-box;
    /* Safari clipping stabilization */
    isolation: isolate;
    position: relative;
    box-sizing: border-box;
}

.board.black,
.board.black_infinite {
    color: #ffffff;
    background-color: #496e53;
    border: 12px solid #364f3c;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/*
 * BLACKBOARD SLATE ARCHITECTURE:
 * Converted directly from vector Adobe Illustrator artboard (Bang-a-a.ai):
 * Artboard: 841.89pt x 595.28pt (A4 Landscape, mapped to 842px x 595px).
 * Grid: 10 rows x 15 columns (14 regular 20mm cells + 1 left number margin).
 * Line 2 Baseline: y = 407.45px.
 * Line 2 Start: x = 96.09px.
 */
.board.blackboard {
    width: 842px;
    height: 595px;
    min-width: 842px;
    min-height: 595px;
    max-width: 100%;
    margin: 12px auto 24px auto;
    background-color: #4e6957;
    background-image: url('/static/img/blackboard.svg');
    background-repeat: no-repeat;
    background-position: 0 0;
    background-size: 842px 595px;
    border: none;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.3);
    position: relative;
    overflow: hidden;
    color: #ffffff;
    border-radius: 4px;
}

.board.blackboard .grid {
    width: 842px;
    height: 595px;
    min-width: 842px;
    min-height: 595px;
    background-image: none !important;
    padding: 0;
    margin: 0;
    position: relative;
    transform: none !important;
    overflow: hidden;
}

.board.blackboard #result,
.board.blackboard .result-text {
    position: absolute;
    left: 96.09px;
    top: 192px; /* Calibrated for 281.5px large font size; baseline at y = 408.05px */
    width: max-content;
    padding: 0;
    margin: 0;
    font-size: 281.5px;
    line-height: 1;
    font-family: HP001, serif;
    color: #ffffff;
    box-sizing: border-box;
    white-space: nowrap;
}

.board.blackboard #result.small,
.board.blackboard .result-text.small {
    font-size: 140.75px;
    top: 300px; /* Calibrated for 140.75px small font size; baseline at y = 408.05px */
}

.board.blackboard #result > p.line,
.board.blackboard .result-text > p.line {
    margin: 0;
    padding: 0;
    line-height: 1;
    white-space: nowrap;
}

.board.blackboard #result > p.line:last-child::after,
.board.blackboard .result-text > p.line:last-child::after {
    display: none !important;
}

.board.blackboard .grid.italics #result,
.board.blackboard.italics #result,
.board.blackboard .grid.italics .result-text,
.board.blackboard.italics .result-text {
    transform: skewX(-17deg);
    transform-origin: 0 var(--baseline-offset, 216px);
}

.board.blackboard .word-handle {
    top: -24px;
}

.board.white {
    color: #2b1055;
    background-color: #ffffff;
    border: 12px solid #e0dfd5;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* 
 * UNIFIED GRID TILE ARCHITECTURE:
 * Both the major lines and minor lines are defined within the EXACT SAME 4x4 repeating tile.
 * display: inline-block + width: max-content ensures the grid expands dynamically with long text,
 * so scrolling to the right NEVER ends early!
 */
.grid {
    display: inline-block;
    width: max-content;
    min-width: 100%;
    min-height: 520px;
    padding-right: 200px; /* Ample grid space after the last character so it never cuts off */
    box-sizing: border-box;
    vertical-align: top;
    position: relative;

    background-size: var(--grid-size) var(--grid-size);
    background-position: var(--grid-unit) calc(var(--grid-unit) * 2.5);
    background-repeat: repeat;
    transition: transform 0.2s ease;
    -webkit-backface-visibility: hidden;
    backface-visibility: hidden;

    background-image:
      /* Vertical lines: Major line at 0, Minor lines at 14.4pt, 28.8pt, 43.2pt */
      linear-gradient(to right,
        var(--grid-major-color) 0, var(--grid-major-color) 1.5px, transparent 1.5px,
        transparent calc(var(--grid-unit) - 0.5px),
        var(--grid-minor-color) calc(var(--grid-unit) - 0.5px), var(--grid-minor-color) calc(var(--grid-unit) + 0.5px), transparent calc(var(--grid-unit) + 0.5px),
        transparent calc(var(--grid-unit) * 2 - 0.5px),
        var(--grid-minor-color) calc(var(--grid-unit) * 2 - 0.5px), var(--grid-minor-color) calc(var(--grid-unit) * 2 + 0.5px), transparent calc(var(--grid-unit) * 2 + 0.5px),
        transparent calc(var(--grid-unit) * 3 - 0.5px),
        var(--grid-minor-color) calc(var(--grid-unit) * 3 - 0.5px), var(--grid-minor-color) calc(var(--grid-unit) * 3 + 0.5px), transparent calc(var(--grid-unit) * 3 + 0.5px),
        transparent var(--grid-size)
      ),
      /* Horizontal lines: Major line at 0, Minor lines at 14.4pt, 28.8pt, 43.2pt */
      linear-gradient(to bottom,
        var(--grid-major-color) 0, var(--grid-major-color) 1.5px, transparent 1.5px,
        transparent calc(var(--grid-unit) - 0.5px),
        var(--grid-minor-color) calc(var(--grid-unit) - 0.5px), var(--grid-minor-color) calc(var(--grid-unit) + 0.5px), transparent calc(var(--grid-unit) + 0.5px),
        transparent calc(var(--grid-unit) * 2 - 0.5px),
        var(--grid-minor-color) calc(var(--grid-unit) * 2 - 0.5px), var(--grid-minor-color) calc(var(--grid-unit) * 2 + 0.5px), transparent calc(var(--grid-unit) * 2 + 0.5px),
        transparent calc(var(--grid-unit) * 3 - 0.5px),
        var(--grid-minor-color) calc(var(--grid-unit) * 3 - 0.5px), var(--grid-minor-color) calc(var(--grid-unit) * 3 + 0.5px), transparent calc(var(--grid-unit) * 3 + 0.5px),
        transparent var(--grid-size)
      );
} 

.black .grid,
.black_infinite .grid {
    --grid-major-color: rgba(220, 220, 220, 0.7);
    --grid-minor-color: rgba(200, 200, 200, 0.32);
}

.white .grid {
    --grid-major-color: rgba(100, 110, 140, 0.5);
    --grid-minor-color: rgba(140, 160, 200, 0.28);
}

.grid.italics {
    -webkit-transform: skewX(-17deg);
    transform: skewX(-17deg);
    -webkit-transform-origin: top left;
    transform-origin: top left;
    will-change: transform;
}

#result {
    width: max-content;
    min-width: 100%;
    padding-left: var(--grid-unit);
    padding-top: calc(var(--grid-unit) * 0.7);
    font-size: 72pt;
    font-family: HP001, serif;
    line-height: calc(72pt + var(--grid-unit) * 3);
    margin-top: 10px;
    letter-spacing: 0;
    user-select: text;
    text-rendering: optimizeLegibility;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    box-sizing: border-box;
}

#result.bold {
    font-weight: bold;
}

#result.small {
    padding-top: calc(var(--grid-unit) * 3.35);
    font-size: 37pt;
    line-height: calc(36pt + var(--grid-unit) * 1.5);
}

#result > p.line:last-child::after {
    content: ' ';
    display: block;
    height: calc(var(--grid-unit) * 3);
}

p.line {
    margin: 0;
    -webkit-margin-before: 0;
    -webkit-margin-after: 0;
    padding: 0;
    position: relative;
    white-space: pre;
}

/* 
 * Word-level inline layout & dragging controls:
 * Each word is an inline-block container with selectable text.
 * A neat handle with a drag icon and reset icon appears at the top left of the word on hover.
 * No text glow on hover; full line & word text selection is preserved!
 */
.word {
    display: inline-block;
    position: relative;
    vertical-align: baseline;
    user-select: text;
    -webkit-user-select: text;
    padding: 0;
    margin: 0;
}

.word-text {
    display: inline-block;
    vertical-align: baseline;
    transform-origin: 0 0;
    user-select: text;
    -webkit-user-select: text;
}

.word-handle {
    position: absolute;
    top: -12px;
    left: 0;
    display: inline-flex;
    align-items: center;
    gap: 3px;
    background: rgba(24, 24, 27, 0.92);
    border: 1px solid rgba(255, 255, 255, 0.28);
    border-radius: 4px;
    padding: 2px 4px;
    z-index: 50;
    user-select: none;
    -webkit-user-select: none;
    font-size: 11px;
    line-height: 1;
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.35);
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.15s ease;
}

.white .word-handle {
    background: rgba(255, 255, 255, 0.95);
    border: 1px solid rgba(0, 0, 0, 0.2);
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.15);
}

.word:hover .word-handle,
.word.is-dragging .word-handle {
    opacity: 1;
    pointer-events: auto;
}

.btn-word-drag,
.btn-word-reset {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 18px;
    height: 18px;
    border-radius: 3px;
    color: #e2e8f0;
    background: transparent;
    border: none;
    padding: 0;
    transition: background 0.15s, color 0.15s;
    touch-action: none;
}

.btn-word-drag i,
.btn-word-reset i {
    pointer-events: none;
}

.white .btn-word-drag,
.white .btn-word-reset {
    color: #334155;
}

.btn-word-drag {
    cursor: grab;
    cursor: -webkit-grab;
}

.btn-word-drag:hover {
    background: #2563eb;
    color: #ffffff;
}

.btn-word-drag.is-dragging,
.word.is-dragging .btn-word-drag {
    cursor: grabbing !important;
    cursor: -webkit-grabbing !important;
    background: #2563eb;
    color: #ffffff;
}

.btn-word-reset {
    cursor: pointer;
}

.btn-word-reset:hover {
    background: #ef4444;
    color: #ffffff;
}

body.is-word-dragging {
    user-select: none !important;
    -webkit-user-select: none !important;
}

/* Word Stretch Dot Handle */
.btn-word-stretch {
    position: absolute;
    right: -5px;
    top: 50%;
    transform: translateY(-50%);
    width: 9px;
    height: 9px;
    border-radius: 50%;
    background: #3b82f6;
    border: 2px solid #ffffff;
    box-shadow: 0 1px 4px rgba(0, 0, 0, 0.4);
    cursor: ew-resize;
    opacity: 0;
    pointer-events: auto;
    transition: opacity 0.15s ease, transform 0.15s ease, background 0.15s ease, border-color 0.15s ease;
    z-index: 60;
    touch-action: none;
    user-select: none;
    -webkit-user-select: none;
}

.white .btn-word-stretch {
    background: #2563eb;
    border-color: #ffffff;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.25);
}

.word:hover .btn-word-stretch,
.btn-word-stretch:hover,
.word.is-stretching .btn-word-stretch {
    opacity: 1;
    pointer-events: auto;
}

.btn-word-stretch:hover,
.btn-word-stretch.is-stretching {
    transform: translateY(-50%) scale(1.3);
    background: #2563eb;
}

.btn-word-stretch.is-snapped {
    background: #10b981 !important;
    border-color: #ecfdf5 !important;
    transform: translateY(-50%) scale(1.45);
}

/* Snap Guideline (vertical dashed line across the line height) */
.snap-guideline {
    position: absolute;
    width: 0;
    border-left: 2px dashed #60a5fa;
    pointer-events: none;
    display: none;
    z-index: 85;
    transition: border-color 0.1s ease;
}

.white .snap-guideline {
    border-left-color: #3b82f6;
}

.snap-guideline.is-snapped {
    border-left: 2px solid #10b981;
}

body.is-word-stretching {
    cursor: ew-resize !important;
    user-select: none !important;
    -webkit-user-select: none !important;
}

.word-space {
    display: inline;
    white-space: pre;
    vertical-align: baseline;
    user-select: text;
    -webkit-user-select: text;
}

/* Print Styles */
@media print {
    body {
        background: #ffffff !important;
        padding: 0 !important;
        margin: 0 !important;
    }

    .no-print {
        display: none !important;
    }

    .board-container {
        padding: 0 !important;
    }

    .board {
        box-shadow: none !important;
        border: none !important;
        margin: 0 !important;
        width: 100% !important;
        max-width: 100% !important;
        background: #ffffff !important;
        color: #000000 !important;
        -webkit-print-color-adjust: exact !important;
        print-color-adjust: exact !important;
    }

    .grid {
        min-width: 100% !important;
        padding-right: 0 !important;
    }

    .board.blackboard {
        width: 842px !important;
        height: 595px !important;
        min-width: 842px !important;
        min-height: 595px !important;
        background-color: #4e6957 !important;
        background-image: url('/static/img/blackboard.svg') !important;
        background-size: 842px 595px !important;
        page-break-after: always;
        break-after: page;
        margin: 0 auto 24px auto !important;
    }



    @page {
        size: A4 portrait;
        margin: 10mm;
    }
}