* { box-sizing: border-box; }

html, body { height: 100%; }

body {
    font-family: Arial, sans-serif;
    display: flex;
    flex-direction: column;
    align-items: center;
    background-color: #f0f0f0;
    margin: 0;
    padding: 12px;
}

h1 {
    color: #4CAF50;
    margin: 0 0 8px 0;
    font-size: 24px;
}

/* ── Controls ─────────────────────────────────────────────────────── */

.controls {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: center;
    gap: 10px;
    padding: 8px 12px;
    margin-bottom: 8px;
    background: #fff;
    border-radius: 8px;
    box-shadow: 0 1px 3px rgba(0,0,0,0.08);
    max-width: 100%;
}

.controls label {
    font-size: 14px;
    color: #333;
    white-space: nowrap;
}

.controls select,
.controls button {
    font-size: 14px;
    padding: 6px 10px;
    border: 1px solid #ccc;
    border-radius: 4px;
    background: #fafafa;
    cursor: pointer;
}

.controls button {
    background: #4CAF50;
    color: white;
    border-color: #3d8b40;
}
.controls button:hover { background: #43a047; }

#hintBtn {
    background: #f9a825;
    border-color: #f57f17;
    color: #333;
    width: 38px;
    height: 38px;
    padding: 0;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    line-height: 1;
}
#hintBtn:hover { background: #f57f17; color: #fff; }

#instructions {
    font-size: 14px;
    color: #555;
    margin-bottom: 10px;
    text-align: center;
}

/* ── Board: [Keypads] | [Product grid] ───────────────────────────── */

#board {
    display: flex;
    flex-direction: row;
    gap: 20px;
    align-items: flex-start;
    margin-bottom: 8px;
    max-width: 100%;
}

/* Left column: Factor A keypad stacked above Factor B keypad */
#keypads-panel {
    display: flex;
    flex-direction: column;
    gap: 18px;
}

.panel-wrap {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 6px;
}

.panel-label {
    font-size: 12px;
    font-weight: bold;
    color: #555;
    letter-spacing: 0.06em;
    text-transform: uppercase;
}

/* ── Keypads (blue, left and right) ──────────────────────────────── */

#keypad-left,
#keypad-right {
    display: grid;
    grid-template-columns: repeat(var(--kp-cols, 3), 1fr);
    gap: 5px;
}

.key-btn {
    width:  52px;
    height: 52px;
    font-size: 20px;
    font-weight: bold;
    background: #1976d2;
    color: #fff;
    border: 2px solid #125aa2;
    border-radius: 8px;
    cursor: pointer;
    user-select: none;
    transition: background 0.12s, transform 0.1s, box-shadow 0.1s;
}

.key-btn:hover {
    background: #1565c0;
    transform: scale(1.07);
}

.key-btn.key-selected {
    background: #fff9c4;
    color: #333;
    border-color: #f9a825;
    box-shadow: 0 0 0 2px #f9a825;
}

/* ── Dim state: keypad not yet active for this step ─────────────── */

/* The dim wrapper fades out its buttons and blocks pointer events */
.keypad-dim .key-btn {
    opacity: 0.28;
    cursor: not-allowed;
    pointer-events: none;
    transform: none !important;
    box-shadow: none !important;
}

/* ── Impossible Factor A: red flash then fade back to normal ─────── */

@keyframes impossibleFlash {
    0%   { background: #e53935; color: #fff; border-color: #b71c1c;
           box-shadow: 0 0 0 3px #ef9a9a; transform: scale(1.14); }
    40%  { background: #e53935; color: #fff; border-color: #b71c1c; }
    100% { background: #1976d2; color: #fff; border-color: #125aa2;
           box-shadow: none;    transform: scale(1); }
}

.key-btn.key-impossible {
    animation: impossibleFlash 0.85s ease-out forwards;
    pointer-events: none;   /* ignore taps during the flash */
}

/* ── Product cards (center panel) ────────────────────────────────── */

#product-panel {
    display: grid;
    grid-template-columns: repeat(var(--prod-cols, 3), 1fr);
    gap: 5px;
}

.prod-card {
    width:  var(--card-size, 58px);
    height: var(--card-size, 58px);
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    border-radius: 8px;
    font-size: var(--card-font, 16px);
    font-weight: bold;
    cursor: pointer;
    user-select: none;
    transition: background 0.15s, transform 0.12s, box-shadow 0.12s;
}

.prod-card:hover:not(.prod-matched) { transform: scale(1.07); }

/* Face-down: card-back pattern (diagonal green stripes) */
.prod-card.prod-down {
    background-color: #388e3c;
    background-image:
        repeating-linear-gradient(
            45deg,
            rgba(255,255,255,0.10) 0px,
            rgba(255,255,255,0.10) 3px,
            transparent 3px,
            transparent 10px
        );
    color: transparent;
    border: 2px solid #2e7d32;
    cursor: default;
}

/* Flip-reveal animation: applied briefly when a card is auto-revealed */
@keyframes cardReveal {
    0%   { transform: scaleX(1);   background-color: #388e3c; }
    40%  { transform: scaleX(0);   background-color: #388e3c; }
    60%  { transform: scaleX(0);   background-color: #fff9c4; }
    100% { transform: scaleX(1);   background-color: #fff9c4; }
}

.prod-card.prod-reveal {
    animation: cardReveal 0.35s ease-in-out forwards;
}

/* Selected / revealed — awaiting factor entry */
.prod-card.prod-selected {
    background: #fff9c4;
    color: #333;
    box-shadow: 0 0 0 3px #f9a825;
    cursor: default;
}

/* Correctly matched — stays visible */
.prod-card.prod-matched {
    background: #2e7d32;
    color: #fff;
    cursor: default;
    transform: none;
    box-shadow: inset 0 0 0 2px #1b5e20;
}
.prod-card.prod-matched:hover { transform: none; }

.prod-emoji-tile {
    position: absolute;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: var(--emoji-font, 160px);
    line-height: 1;
    pointer-events: none;
    user-select: none;
}

/* ── Status line ──────────────────────────────────────────────────── */

#status {
    min-height: 1.4em;
    font-size: 16px;
    color: #555;
    margin-bottom: 8px;
    text-align: center;
}

/* ── Timer (fixed bottom-left) ───────────────────────────────────── */

#timer {
    position: fixed;
    left: 12px;
    bottom: 12px;
    background: #fff;
    border-radius: 8px;
    padding: 8px 12px;
    box-shadow: 0 1px 3px rgba(0,0,0,0.12);
    font-family: Menlo, Consolas, monospace;
    font-size: 13px;
    color: #333;
    display: flex;
    flex-wrap: wrap;
    align-items: flex-start;
    gap: 14px;
    z-index: 5;
}

.timer-col {
    display: flex;
    flex-direction: column;
    gap: 2px;
    min-width: 110px;
}

.timer-col-score {
    min-width: 0;
    justify-content: center;
}

.timer-col-score .timer-row {
    justify-content: flex-start;
    gap: 6px;
}

#timer .timer-row {
    display: flex;
    justify-content: space-between;
    gap: 8px;
}

#timeBest, #picksBest { color: #4CAF50; font-weight: bold; }

/* ── Hint overlay — N×N multiplication table ─────────────────────── */

#hintOverlay {
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.72);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 50;
}
#hintOverlay[hidden] { display: none; }

#hintBox {
    background: #fff;
    border-radius: 10px;
    padding: 14px 16px;
    box-shadow: 0 12px 36px rgba(0,0,0,0.35);
    max-width:  calc(100vw - 24px);
    max-height: calc(100vh - 40px);
    overflow: auto;
}

#hintHeader {
    font-size: 14px;
    font-weight: bold;
    color: #333;
    margin-bottom: 10px;
    text-align: center;
}

#hintCountdown { color: #999; font-weight: normal; margin-left: 6px; }

#multiTable {
    border-collapse: collapse;
    font-family: Menlo, Consolas, monospace;
}

/* Cell sizing scales with level via CSS — Level 4 needs smaller cells */
#multiTable th,
#multiTable td {
    width:  28px;
    height: 24px;
    font-size: 11px;
    text-align: center;
    border: 1px solid #e0e0e0;
    padding: 0;
}

#multiTable th {
    background: #1976d2;
    color: #fff;
    font-weight: bold;
}

.hint-corner          { background: #0d47a1 !important; font-size: 13px; }
.hint-diagonal        { background: #e8f5e9; color: #2e7d32; }
.hint-factor-header   { background: #f9a825 !important; color: #333 !important; }
.hint-factor-col      { background: #fff9c4; }
.hint-match           { background: #4CAF50 !important; color: #fff !important; font-weight: bold; }

/* ── Win banner (fixed bottom-right) ─────────────────────────────── */

#winBanner {
    position: fixed;
    display: flex;
    align-items: center;
    justify-content: center;
    right: 12px;
    bottom: 12px;
    z-index: 20;
    animation: winToastIn 0.28s ease-out;
}
#winBanner[hidden] { display: none; }

.winner-card {
    background: white;
    width: min(360px, calc(100vw - 24px));
    padding: 16px 18px;
    border: 1px solid rgba(76,175,80,0.28);
    border-radius: 8px;
    text-align: left;
    box-shadow: 0 8px 24px rgba(0,0,0,0.18);
}

.winner-card h2 {
    margin: 0 0 12px 0;
    color: #4CAF50;
    font-size: 1rem;
    line-height: 1.25;
}

.winner-card button {
    font-size: 16px;
    padding: 10px 20px;
    background: #4CAF50;
    color: white;
    border: none;
    border-radius: 6px;
    cursor: pointer;
}
.winner-card button:hover { background: #43a047; }

/* ── Frog parade ─────────────────────────────────────────────────── */

#frogParade {
    position: fixed;
    inset: 0;
    overflow: hidden;
    pointer-events: none;
    z-index: 15;
}

.frog {
    position: absolute;
    left: 100vw;
    top: var(--lane, 50vh);
    font-size: var(--size, 42px);
    line-height: 1;
    filter: drop-shadow(0 8px 5px rgba(0,0,0,0.2));
    animation: frogCross var(--duration, 6s) linear var(--delay, 0s) forwards;
    will-change: transform;
}

.frog-icon {
    display: block;
    animation: frogHop 0.48s ease-in-out var(--delay, 0s) infinite;
    will-change: transform;
}

/* ── Keyframes ───────────────────────────────────────────────────── */

@keyframes winToastIn {
    from { opacity: 0; transform: translate(16px, 16px) scale(0.96); }
    to   { opacity: 1; transform: translate(0, 0) scale(1); }
}

@keyframes frogCross {
    from { transform: translateX(8vw); }
    to   { transform: translateX(calc(-120vw - var(--drift, 0px))); }
}

@keyframes frogHop {
    0%, 100% { transform: translateY(0) rotate(-5deg); }
    45%      { transform: translateY(calc(-1 * var(--jump, 24px))) rotate(7deg); }
}

@media (max-width: 980px), (max-height: 820px) {
    #board { gap: 16px; }

    #keypads-panel { gap: 14px; }

    .key-btn {
        width: 48px;
        height: 48px;
        font-size: 18px;
    }

    .prod-card {
        width: calc(var(--card-size, 58px) * 0.92) !important;
        height: calc(var(--card-size, 58px) * 0.92) !important;
        font-size: calc(var(--card-font, 16px) * 0.94) !important;
    }

    .prod-emoji-tile { font-size: calc(var(--emoji-font, 160px) * 0.92); }

    #timer {
        position: static;
        left: auto;
        bottom: auto;
        transform: none;
        margin-top: 8px;
    }
}

/* ── Responsive: stack panels vertically on narrow screens ───────── */

@media (max-width: 640px) {
    body { padding: 8px; }
    h1 { font-size: 18px; margin-bottom: 6px; }

    .controls { gap: 8px; padding: 6px 10px; margin-bottom: 6px; }
    .controls label { font-size: 12px; }
    .controls select, .controls button { font-size: 12px; padding: 5px 8px; }
    #hintBtn { width: 34px; height: 34px; padding: 0; font-size: 18px; }

    /* Stack everything vertically on narrow screens */
    #board {
        flex-direction: column;
        align-items: center;
        gap: 14px;
    }

    /* Keypads side-by-side inside the stacked panel */
    #keypads-panel {
        flex-direction: row;
        gap: 16px;
    }

    .key-btn  { width: 42px; height: 42px; font-size: 16px; }
    .prod-card { width: calc(var(--card-size, 58px) * 0.8) !important;
                 height: calc(var(--card-size, 58px) * 0.8) !important;
                 font-size: calc(var(--card-font, 16px) * 0.85) !important; }
    .prod-emoji-tile { font-size: calc(var(--emoji-font, 160px) * 0.8); }

    #multiTable th, #multiTable td { width: 20px; height: 18px; font-size: 9px; }

    #winBanner { right: 8px; bottom: 8px; }
    .winner-card { width: min(320px, calc(100vw - 16px)); padding: 12px 14px; }
    .winner-card h2 { font-size: 0.95rem; margin-bottom: 10px; }
    .winner-card button { font-size: 14px; padding: 8px 16px; }

    #timer {
        position: static;
        left: auto;
        bottom: auto;
        transform: none;
        gap: 10px; font-size: 11px; padding: 6px 10px;
    }
    .timer-col { min-width: 80px; }
}

@media (prefers-reduced-motion: reduce) {
    #winBanner, .frog, .frog-icon { animation: none; }
    .frog { display: none; }
}