:root {
    --chalk-board-bg: #213e2c;
    --chalk-board-edge: #6b4a2a;
    --chalk-board-frame: #8a6536;
    --chalk-ink: rgba(248, 247, 240, 0.92);
    --chalk-ink-dim: rgba(248, 247, 240, 0.55);
    --chalk-page-bg: #1a1a1a;
}

.chalk-page {
    min-height: calc(100vh - 80px);
    background: radial-gradient(ellipse at top, #2a2a2a 0%, #141414 70%);
    color: #f1ede4;
    padding: 36px 20px 80px;
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    box-sizing: border-box;
}

.chalk-page-head {
    max-width: 720px;
    margin: 0 auto 28px;
    text-align: center;
}

.chalk-eyebrow {
    display: inline-block;
    font-size: 11px;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    color: #d4a574;
    padding: 4px 10px;
    border: 1px solid rgba(212, 165, 116, 0.4);
    border-radius: 999px;
    margin-bottom: 14px;
}

.chalk-title {
    font-family: 'Caveat', cursive;
    font-weight: 700;
    font-size: clamp(38px, 6vw, 56px);
    margin: 0 0 8px;
    color: #fff;
    letter-spacing: 0.01em;
}

.chalk-sub {
    margin: 0;
    font-size: 15px;
    color: #b8b3a8;
    line-height: 1.5;
}

.chalk-stage {
    max-width: 720px;
    margin: 0 auto;
}

.chalk-board {
    position: relative;
    background:
        linear-gradient(180deg, rgba(255, 255, 255, 0.04) 0%, transparent 30%),
        radial-gradient(ellipse at 30% 20%, rgba(255, 255, 255, 0.06) 0%, transparent 60%),
        var(--chalk-board-bg);
    border-radius: 8px;
    padding: 22px 22px 24px;
    box-shadow:
        0 0 0 10px var(--chalk-board-frame),
        0 0 0 12px var(--chalk-board-edge),
        0 24px 48px -16px rgba(0, 0, 0, 0.7),
        inset 0 0 60px rgba(0, 0, 0, 0.35);
    display: flex;
    flex-direction: column;
    min-height: min(60vh, 460px);
    touch-action: none;
    user-select: none;
    -webkit-user-select: none;
    cursor: crosshair;
    overflow: hidden;
}

.chalk-board::before {
    content: '';
    position: absolute;
    inset: 0;
    background-image:
        radial-gradient(circle at 12% 30%, rgba(255, 255, 255, 0.04) 0.5px, transparent 1px),
        radial-gradient(circle at 78% 60%, rgba(255, 255, 255, 0.03) 0.5px, transparent 1px),
        radial-gradient(circle at 45% 80%, rgba(255, 255, 255, 0.025) 0.5px, transparent 1px);
    background-size: 80px 80px, 120px 120px, 100px 100px;
    pointer-events: none;
    opacity: 0.5;
}

.chalk-count {
    position: relative;
    z-index: 2;
    align-self: flex-end;
    display: flex;
    align-items: baseline;
    gap: 6px;
    font-family: 'Caveat', cursive;
    color: var(--chalk-ink);
    pointer-events: none;
}

.chalk-count-num {
    font-size: 42px;
    font-weight: 700;
    line-height: 1;
    letter-spacing: 0.04em;
}

.chalk-count-label {
    font-size: 14px;
    color: var(--chalk-ink-dim);
    text-transform: lowercase;
}

.chalk-active {
    position: relative;
    z-index: 1;
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 200px;
    margin: 8px 0 12px;
    transition: opacity 320ms ease, transform 320ms ease;
}

.chalk-active.is-flushing {
    opacity: 0;
    transform: translateY(20px) scale(0.7);
}

.chalk-svg {
    width: 180px;
    height: 220px;
    pointer-events: none;
}

.chalk-stack {
    position: relative;
    z-index: 1;
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    min-height: 92px;
    padding-top: 12px;
    border-top: 1px dashed rgba(248, 247, 240, 0.18);
    align-content: flex-start;
}

.chalk-group-tile {
    width: 64px;
    height: 80px;
    transition: opacity 200ms ease, transform 320ms cubic-bezier(0.22, 1, 0.36, 1);
    pointer-events: none;
}

.chalk-group-tile.is-entering {
    opacity: 0;
    transform: translateY(-40px) scale(1.4);
}

.chalk-group-tile.is-removing {
    opacity: 0;
    transform: scale(0.6);
}

.chalk-group-tile .chalk-svg {
    width: 100%;
    height: 100%;
}

.chalk-stroke {
    stroke: var(--chalk-ink);
    stroke-width: 4.5;
    stroke-linecap: round;
    fill: none;
}

.chalk-stroke.is-slash {
    stroke-width: 5;
}

/* ── Fullscreen FAB pinned inside the chalkboard ────────────────────── */
.chalk-fab {
    position: absolute;
    top: 12px;
    left: 12px;
    z-index: 3;
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: rgba(0, 0, 0, 0.35);
    border: 1px solid rgba(232, 227, 213, 0.25);
    color: rgba(248, 247, 240, 0.85);
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 13px;
    transition: background-color 150ms ease, border-color 150ms ease, color 150ms ease;
    -webkit-tap-highlight-color: transparent;
    padding: 0;
}

.chalk-fab:hover {
    background: rgba(0, 0, 0, 0.55);
    border-color: rgba(232, 227, 213, 0.5);
    color: #fff;
}

.chalk-fab .fa-compress { display: none; }
.chalk-stage.is-fullscreen .chalk-fab .fa-expand,
.chalk-stage:fullscreen .chalk-fab .fa-expand { display: none; }
.chalk-stage.is-fullscreen .chalk-fab .fa-compress,
.chalk-stage:fullscreen .chalk-fab .fa-compress { display: inline; }

/* ── Controls ────────────────────────────────────────────────────────── */
.chalk-controls {
    display: flex;
    gap: 12px;
    justify-content: center;
    flex-wrap: wrap;
    margin-top: 18px;
}

.chalk-btn {
    appearance: none;
    background: transparent;
    color: #e8e3d5;
    border: 1px solid rgba(232, 227, 213, 0.35);
    padding: 10px 18px;
    border-radius: 999px;
    font-family: inherit;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: background-color 150ms ease, border-color 150ms ease, color 150ms ease;
    -webkit-tap-highlight-color: transparent;
    display: inline-flex;
    align-items: center;
    gap: 6px;
    white-space: nowrap;
}

.chalk-btn:hover {
    background: rgba(232, 227, 213, 0.1);
    border-color: rgba(232, 227, 213, 0.6);
}

.chalk-btn:active {
    transform: translateY(1px);
}

.chalk-btn-share {
    color: #a8d5ff;
    border-color: rgba(168, 213, 255, 0.4);
}

.chalk-btn-share:hover {
    background: rgba(168, 213, 255, 0.12);
    border-color: rgba(168, 213, 255, 0.7);
}

.chalk-btn-danger {
    color: #f4b393;
    border-color: rgba(244, 179, 147, 0.35);
}

.chalk-btn-danger:hover {
    background: rgba(244, 179, 147, 0.1);
    border-color: rgba(244, 179, 147, 0.6);
}

.chalk-hint {
    text-align: center;
    color: #888577;
    font-size: 13px;
    margin: 14px 0 0;
}

.chalk-hint kbd {
    display: inline-block;
    background: #2a2a2a;
    border: 1px solid #3a3a3a;
    border-radius: 4px;
    padding: 2px 8px;
    font-family: ui-monospace, monospace;
    font-size: 12px;
    color: #d4d0c4;
}

.chalk-hint-mobile { display: none; }
.chalk-hint-desktop { display: inline; }

@media (hover: none) and (pointer: coarse) {
    .chalk-hint-mobile { display: inline; }
    .chalk-hint-desktop { display: none; }
}

.chalk-page-foot {
    max-width: 720px;
    margin: 24px auto 0;
    text-align: center;
    color: #6b665a;
    font-size: 12px;
}

.chalk-page-foot p { margin: 0; }

/* ── Educational content + FAQ ───────────────────────────────────────── */
.chalk-edu,
.chalk-faq {
    margin-top: 60px;
}

.chalk-edu-inner {
    max-width: 980px;
    margin: 0 auto;
    padding: 0 4px;
}

.chalk-edu-h2 {
    font-family: 'Caveat', cursive;
    font-weight: 700;
    font-size: clamp(28px, 4vw, 40px);
    color: #f1ede4;
    text-align: center;
    margin: 0 0 28px;
    letter-spacing: 0.01em;
}

.chalk-edu-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 18px;
}

.chalk-edu-card {
    background: rgba(255, 255, 255, 0.025);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: 14px;
    padding: 22px 24px 24px;
}

.chalk-edu-card-wide { grid-column: span 2; }

.chalk-edu-card h3 {
    font-family: 'Caveat', cursive;
    font-size: 26px;
    font-weight: 700;
    color: #f1ede4;
    margin: 0 0 12px;
    letter-spacing: 0.01em;
}

.chalk-edu-card p {
    margin: 0 0 10px;
    color: #c8c4b9;
    font-size: 15px;
    line-height: 1.6;
}

.chalk-edu-card p:last-child { margin-bottom: 0; }
.chalk-edu-card strong { color: #f1ede4; font-weight: 600; }
.chalk-edu-card em { font-style: italic; color: #d4c89e; }
.chalk-edu-card a {
    color: #a8d5ff;
    text-decoration: underline;
    text-decoration-color: rgba(168, 213, 255, 0.4);
    text-underline-offset: 2px;
}
.chalk-edu-card a:hover { color: #c7e1ff; text-decoration-color: #c7e1ff; }
.chalk-edu-card code {
    font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
    font-size: 13px;
    color: #f4dc9d;
    background: rgba(0, 0, 0, 0.25);
    padding: 1px 6px;
    border-radius: 4px;
}

.chalk-edu-figure {
    margin: 14px 0 0;
    background:
        linear-gradient(180deg, rgba(255, 255, 255, 0.03) 0%, transparent 30%),
        var(--chalk-board-bg);
    border-radius: 8px;
    padding: 14px 16px 10px;
    box-shadow:
        0 0 0 4px var(--chalk-board-frame),
        0 0 0 5px var(--chalk-board-edge),
        inset 0 0 30px rgba(0, 0, 0, 0.35);
}

.chalk-edu-figure svg {
    display: block;
    width: 100%;
    height: auto;
    max-height: 110px;
}

.chalk-edu-figure figcaption {
    margin-top: 8px;
    font-size: 12px;
    color: #888577;
    text-align: center;
    font-style: italic;
}

.chalk-edu-steps {
    margin: 0 0 14px;
    padding-left: 1.2em;
    color: #c8c4b9;
    font-size: 15px;
    line-height: 1.65;
}

.chalk-edu-steps li { margin-bottom: 6px; }
.chalk-edu-steps li::marker { color: #d4a574; }

.chalk-edu-kids-note {
    margin: 14px 0 0;
    padding: 12px 14px;
    background: rgba(212, 165, 116, 0.08);
    border-left: 3px solid #d4a574;
    border-radius: 0 8px 8px 0;
    color: #d8d2c2;
    font-size: 14px;
    line-height: 1.55;
}
.chalk-edu-kids-note strong { color: #f1ede4; }

.chalk-faq-list {
    display: grid;
    gap: 14px;
}

.chalk-faq-item {
    background: rgba(255, 255, 255, 0.025);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: 12px;
    padding: 18px 22px;
}

.chalk-faq-q {
    margin: 0 0 8px;
    color: #f1ede4;
    font-size: 16px;
    font-weight: 600;
    line-height: 1.35;
}

.chalk-faq-a {
    margin: 0;
    color: #c8c4b9;
    font-size: 14.5px;
    line-height: 1.6;
}

@media (max-width: 720px) {
    .chalk-edu-grid { grid-template-columns: 1fr; }
    .chalk-edu-card-wide { grid-column: span 1; }
    .chalk-edu, .chalk-faq { margin-top: 44px; }
}

/* ── Mobile portrait ─────────────────────────────────────────────────── */
@media (max-width: 600px) {
    .chalk-page { padding: 20px 12px 56px; }
    .chalk-page-head { margin-bottom: 20px; }
    .chalk-board {
        min-height: min(58vh, 420px);
        padding: 18px 16px 20px;
        box-shadow:
            0 0 0 8px var(--chalk-board-frame),
            0 0 0 10px var(--chalk-board-edge),
            0 16px 32px -12px rgba(0, 0, 0, 0.7),
            inset 0 0 40px rgba(0, 0, 0, 0.35);
    }
    .chalk-svg { width: 150px; height: 180px; }
    .chalk-group-tile { width: 54px; height: 68px; }
    .chalk-count-num { font-size: 36px; }
    .chalk-fab { top: 10px; left: 10px; width: 34px; height: 34px; }
    .chalk-btn { padding: 9px 14px; font-size: 13px; }
}

/* ── Short viewports / mobile landscape ──────────────────────────────── */
@media (max-height: 560px) and (orientation: landscape) {
    .chalk-page {
        min-height: 100vh;
        padding: 12px 16px 16px;
        display: flex;
        flex-direction: column;
    }
    .chalk-page-head { display: none; }
    .chalk-page-foot { display: none; }
    .chalk-hint { display: none; }
    .chalk-stage { flex: 1; display: flex; flex-direction: column; }
    .chalk-board {
        flex: 1;
        min-height: 0;
        padding: 14px 18px 14px;
        box-shadow:
            0 0 0 6px var(--chalk-board-frame),
            0 0 0 8px var(--chalk-board-edge),
            0 8px 20px -8px rgba(0, 0, 0, 0.7),
            inset 0 0 30px rgba(0, 0, 0, 0.35);
    }
    .chalk-svg { width: clamp(120px, 22vh, 180px); height: clamp(140px, 26vh, 220px); }
    .chalk-stack { min-height: 60px; padding-top: 8px; }
    .chalk-group-tile { width: 48px; height: 60px; }
    .chalk-count-num { font-size: 30px; }
    .chalk-controls { margin-top: 10px; gap: 8px; }
    .chalk-btn { padding: 7px 14px; font-size: 12px; }
    .chalk-fab { top: 8px; left: 8px; width: 30px; height: 30px; font-size: 11px; }
}

/* ── Fullscreen state (works for both :fullscreen + .is-fullscreen) ──── */
.chalk-stage:fullscreen,
.chalk-stage.is-fullscreen {
    background: #0c0c0c;
    padding: 28px;
    width: 100vw;
    height: 100vh;
    max-width: none;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}

.chalk-stage:-webkit-full-screen {
    background: #0c0c0c;
    padding: 28px;
    width: 100vw;
    height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}

.chalk-stage:fullscreen .chalk-board,
.chalk-stage.is-fullscreen .chalk-board,
.chalk-stage:-webkit-full-screen .chalk-board {
    flex: 1;
    width: 100%;
    max-width: 1100px;
    min-height: 0;
    padding: 36px 40px 36px;
    box-shadow:
        0 0 0 14px var(--chalk-board-frame),
        0 0 0 16px var(--chalk-board-edge),
        0 40px 80px -20px rgba(0, 0, 0, 0.9),
        inset 0 0 100px rgba(0, 0, 0, 0.4);
}

.chalk-stage:fullscreen .chalk-svg,
.chalk-stage.is-fullscreen .chalk-svg,
.chalk-stage:-webkit-full-screen .chalk-svg {
    width: clamp(220px, 28vmin, 360px);
    height: clamp(260px, 34vmin, 440px);
}

.chalk-stage:fullscreen .chalk-count-num,
.chalk-stage.is-fullscreen .chalk-count-num,
.chalk-stage:-webkit-full-screen .chalk-count-num {
    font-size: clamp(48px, 6vmin, 72px);
}

.chalk-stage:fullscreen .chalk-count-label,
.chalk-stage.is-fullscreen .chalk-count-label,
.chalk-stage:-webkit-full-screen .chalk-count-label {
    font-size: 18px;
}

.chalk-stage:fullscreen .chalk-group-tile,
.chalk-stage.is-fullscreen .chalk-group-tile,
.chalk-stage:-webkit-full-screen .chalk-group-tile {
    width: 84px;
    height: 104px;
}

.chalk-stage:fullscreen .chalk-stack,
.chalk-stage.is-fullscreen .chalk-stack,
.chalk-stage:-webkit-full-screen .chalk-stack {
    min-height: 116px;
    gap: 14px;
}

.chalk-stage:fullscreen .chalk-controls,
.chalk-stage.is-fullscreen .chalk-controls,
.chalk-stage:-webkit-full-screen .chalk-controls {
    margin-top: 22px;
}

.chalk-stage:fullscreen .chalk-fab,
.chalk-stage.is-fullscreen .chalk-fab,
.chalk-stage:-webkit-full-screen .chalk-fab {
    width: 44px;
    height: 44px;
    top: 18px;
    left: 18px;
    font-size: 16px;
}