.bkbg-ttr-app {
    box-sizing: border-box;
    padding: 28px 16px;
    font-family: 'Helvetica Neue', Arial, sans-serif;
    user-select: none;
}

.bkbg-ttr-app .bkbg-ttr-title {
    text-align: center;
    margin: 0 0 4px;
    font-family: var(--bkttr-tt-ff);
    font-size: var(--bkttr-tt-fs-d, 28px);
    line-height: var(--bkttr-tt-lh-d, 1.15);
    letter-spacing: var(--bkttr-tt-ls-d);
    word-spacing: var(--bkttr-tt-ws-d);
    font-weight: var(--bkttr-tt-fw, 700);
    font-style: var(--bkttr-tt-fst);
    text-decoration: var(--bkttr-tt-td);
    text-transform: var(--bkttr-tt-tt);
}

.bkbg-ttr-app .bkbg-ttr-subtitle {
    text-align: center;
    margin: 0 0 18px;
    opacity: 0.65;
    font-family: var(--bkttr-st-ff);
    font-size: var(--bkttr-st-fs-d, 14px);
    line-height: var(--bkttr-st-lh-d, 1.4);
    letter-spacing: var(--bkttr-st-ls-d);
    word-spacing: var(--bkttr-st-ws-d);
    font-weight: var(--bkttr-st-fw, 400);
    font-style: var(--bkttr-st-fst);
    text-decoration: var(--bkttr-st-td);
    text-transform: var(--bkttr-st-tt);
}

/* ── Responsive typography ──────────────────────────────── */
@media (max-width: 1024px) {
    .bkbg-ttr-app .bkbg-ttr-title {
        font-size: var(--bkttr-tt-fs-t, var(--bkttr-tt-fs-d, 28px));
        line-height: var(--bkttr-tt-lh-t, var(--bkttr-tt-lh-d, 1.15));
        letter-spacing: var(--bkttr-tt-ls-t, var(--bkttr-tt-ls-d));
        word-spacing: var(--bkttr-tt-ws-t, var(--bkttr-tt-ws-d));
    }
    .bkbg-ttr-app .bkbg-ttr-subtitle {
        font-size: var(--bkttr-st-fs-t, var(--bkttr-st-fs-d, 14px));
        line-height: var(--bkttr-st-lh-t, var(--bkttr-st-lh-d, 1.4));
        letter-spacing: var(--bkttr-st-ls-t, var(--bkttr-st-ls-d));
        word-spacing: var(--bkttr-st-ws-t, var(--bkttr-st-ws-d));
    }
}
@media (max-width: 767px) {
    .bkbg-ttr-app .bkbg-ttr-title {
        font-size: var(--bkttr-tt-fs-m, var(--bkttr-tt-fs-t, var(--bkttr-tt-fs-d, 28px)));
        line-height: var(--bkttr-tt-lh-m, var(--bkttr-tt-lh-t, var(--bkttr-tt-lh-d, 1.15)));
        letter-spacing: var(--bkttr-tt-ls-m, var(--bkttr-tt-ls-t, var(--bkttr-tt-ls-d)));
        word-spacing: var(--bkttr-tt-ws-m, var(--bkttr-tt-ws-t, var(--bkttr-tt-ws-d)));
    }
    .bkbg-ttr-app .bkbg-ttr-subtitle {
        font-size: var(--bkttr-st-fs-m, var(--bkttr-st-fs-t, var(--bkttr-st-fs-d, 14px)));
        line-height: var(--bkttr-st-lh-m, var(--bkttr-st-lh-t, var(--bkttr-st-lh-d, 1.4)));
        letter-spacing: var(--bkttr-st-ls-m, var(--bkttr-st-ls-t, var(--bkttr-st-ls-d)));
        word-spacing: var(--bkttr-st-ws-m, var(--bkttr-st-ws-t, var(--bkttr-st-ws-d)));
    }
}

/* ---- Layout ---- */

.bkbg-ttr-layout {
    display: flex;
    justify-content: center;
    align-items: flex-start;
    gap: 16px;
    flex-wrap: wrap;
}

/* ---- Canvas board ---- */

.bkbg-ttr-canvas {
    display: block;
    image-rendering: pixelated;
    border-radius: 4px;
    flex-shrink: 0;
}

/* ---- Side panel ---- */

.bkbg-ttr-panel {
    display: flex;
    flex-direction: column;
    min-width: 110px;
    gap: 8px;
}

.bkbg-ttr-stat-box {
    border-radius: 8px;
    padding: 10px 14px;
}

.bkbg-ttr-stat-label {
    font-size: 11px;
    font-weight: 700;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    margin-bottom: 3px;
}

.bkbg-ttr-stat-value {
    font-size: 22px;
    font-weight: 700;
}

.bkbg-ttr-next-canvas {
    display: block;
    border-radius: 4px;
}

/* ---- On-screen controls ---- */

.bkbg-ttr-controls {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 5px;
    margin-top: 10px;
}

.bkbg-ttr-ctrl-row {
    display: flex;
    gap: 5px;
}

.bkbg-ttr-btn {
    width: 46px;
    height: 46px;
    border: none;
    border-radius: 8px;
    font-size: 18px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: filter 0.1s, transform 0.1s;
    font-weight: 700;
}

.bkbg-ttr-btn:active {
    transform: scale(0.9);
    filter: brightness(0.85);
}

.bkbg-ttr-start-btn {
    width: 100%;
    border: none;
    border-radius: 8px;
    padding: 10px 0;
    font-size: 14px;
    font-weight: 700;
    cursor: pointer;
    transition: filter 0.15s, transform 0.1s;
    letter-spacing: 0.04em;
    text-transform: uppercase;
}

.bkbg-ttr-start-btn:hover {
    filter: brightness(1.1);
    transform: translateY(-1px);
}

.bkbg-ttr-keys-hint {
    font-size: 11px;
    opacity: 0.45;
    line-height: 1.7;
}

/* ---- Responsive ---- */

@media (max-width: 520px) {
    .bkbg-ttr-app { padding: 16px 8px; }
    .bkbg-ttr-layout { gap: 10px; }
    .bkbg-ttr-panel { min-width: 90px; }
    .bkbg-ttr-stat-value { font-size: 18px; }
}