:root {
    --sudoku-ink: #112132;
    --sudoku-muted: #607085;
    --sudoku-line: rgba(17, 33, 50, 0.14);
    --sudoku-strong-line: rgba(17, 33, 50, 0.34);
    --sudoku-paper: rgba(255, 255, 255, 0.88);
    --sudoku-paper-strong: rgba(255, 255, 255, 0.96);
    --sudoku-accent: #0f766e;
    --sudoku-accent-soft: rgba(15, 118, 110, 0.14);
    --sudoku-conflict: #b91c1c;
    --sudoku-conflict-soft: rgba(185, 28, 28, 0.14);
    --sudoku-given: #12263f;
    --sudoku-filled: #2563eb;
}

body.sudoku-page {
    min-height: 100vh;
    padding-top: var(--app-topbar-offset, 78px);
    color: var(--sudoku-ink);
    background:
        radial-gradient(circle at top left, rgba(37, 99, 235, 0.18), transparent 30%),
        radial-gradient(circle at right center, rgba(15, 118, 110, 0.16), transparent 32%),
        linear-gradient(180deg, #f4f7fb 0%, #eef3f8 100%);
}

.sudoku-hero {
    display: block;
    margin-bottom: 1.5rem;
}

.sudoku-hero__copy,
.sudoku-main-card {
    background: var(--sudoku-paper);
    border: 1px solid rgba(255, 255, 255, 0.7);
    backdrop-filter: blur(16px);
    box-shadow: 0 30px 80px rgba(15, 23, 42, 0.08);
}

.sudoku-hero__copy {
    border-radius: 28px;
    padding: 1.5rem 1.6rem;
}

.sudoku-hero__kicker {
    display: inline-block;
    margin-bottom: 0.75rem;
    color: var(--sudoku-accent);
    font-size: 0.76rem;
    font-weight: 700;
    letter-spacing: 0.14em;
    text-transform: uppercase;
}

.sudoku-hero__title {
    margin: 0;
    font-size: clamp(2rem, 4vw, 3.25rem);
    line-height: 0.96;
    letter-spacing: -0.05em;
}

.sudoku-hero__subtitle {
    max-width: 52rem;
    margin: 0.9rem 0 0;
    color: var(--sudoku-muted);
    font-size: 1rem;
    line-height: 1.6;
}

.sudoku-hero__art {
    display: grid;
    place-items: center;
    min-height: 180px;
    border-radius: 28px;
    background:
        linear-gradient(145deg, rgba(17, 33, 50, 0.96), rgba(32, 48, 68, 0.96)),
        var(--sudoku-paper-strong);
    box-shadow: 0 24px 60px rgba(15, 23, 42, 0.18);
}

.sudoku-hero__art-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 0.5rem;
    width: min(180px, 80%);
    aspect-ratio: 1;
}

.sudoku-hero__art-grid span {
    display: grid;
    place-items: center;
    border-radius: 18px;
    background: rgba(255, 255, 255, 0.08);
    color: #f8fafc;
    font-size: 1.55rem;
    font-weight: 800;
}

.sudoku-main-card {
    border-radius: 32px;
    padding: 1.25rem;
}

.sudoku-toolbar,
.sudoku-game {
    display: flex;
    gap: 1rem;
}

.sudoku-toolbar {
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    margin-bottom: 1rem;
}

.sudoku-toolbar__group,
.sudoku-toolbar__actions {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    flex-wrap: wrap;
}

.sudoku-toolbar__label,
.sudoku-pad-card__label {
    margin: 0;
    color: var(--sudoku-muted);
    font-size: 0.82rem;
    font-weight: 700;
    letter-spacing: 0.08em;
    text-transform: uppercase;
}

.sudoku-toolbar__select {
    width: auto;
    min-width: 140px;
}

.sudoku-game {
    align-items: flex-start;
}

.sudoku-board-wrap {
    flex: 1 1 540px;
}

.sudoku-board {
    display: grid;
    grid-template-columns: repeat(9, minmax(0, 1fr));
    width: min(100%, 680px);
    aspect-ratio: 1;
    padding: 0.5rem;
    border-radius: 28px;
    background: var(--sudoku-paper-strong);
    box-shadow: inset 0 0 0 1px rgba(148, 163, 184, 0.18);
}

.sudoku-cell {
    position: relative;
    display: grid;
    place-items: center;
    padding: 0;
    border: 1px solid var(--sudoku-line);
    background: transparent;
    color: var(--sudoku-filled);
    font-size: clamp(1rem, 2.3vw, 1.7rem);
    font-weight: 700;
    line-height: 1;
    transition: background-color 120ms ease, color 120ms ease, box-shadow 120ms ease;
}

.sudoku-cell[data-col="2"],
.sudoku-cell[data-col="5"] {
    border-right-color: var(--sudoku-strong-line);
    border-right-width: 2px;
}

.sudoku-cell[data-row="2"],
.sudoku-cell[data-row="5"] {
    border-bottom-color: var(--sudoku-strong-line);
    border-bottom-width: 2px;
}

.sudoku-cell.is-given {
    color: var(--sudoku-given);
    background: rgba(17, 33, 50, 0.035);
}

.sudoku-cell.is-selected {
    background: rgba(37, 99, 235, 0.12);
    box-shadow: inset 0 0 0 2px rgba(37, 99, 235, 0.35);
}

.sudoku-cell.is-related {
    background: rgba(37, 99, 235, 0.06);
}

.sudoku-cell.is-conflict {
    background: var(--sudoku-conflict-soft);
    color: var(--sudoku-conflict);
}

.sudoku-cell__notes {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    grid-template-rows: repeat(3, 1fr);
    width: 100%;
    height: 100%;
    padding: 0.32rem;
    color: var(--sudoku-muted);
    font-size: clamp(0.48rem, 1vw, 0.72rem);
    font-weight: 600;
}

.sudoku-cell__notes span {
    display: grid;
    place-items: center;
}

.sudoku-sidepanel {
    flex: 0 0 min(100%, 280px);
    display: grid;
    gap: 1rem;
}

.sudoku-status-card,
.sudoku-pad-card,
.sudoku-legend {
    padding: 1rem;
    border-radius: 24px;
    background: var(--sudoku-paper-strong);
    box-shadow: inset 0 0 0 1px rgba(148, 163, 184, 0.16);
}

.sudoku-status-card__row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 0.75rem;
    margin-bottom: 0.85rem;
}

.sudoku-status-card__label {
    font-size: 0.82rem;
    font-weight: 700;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--sudoku-muted);
}

.sudoku-status-card__status {
    min-height: 2.5rem;
    margin-bottom: 0.75rem;
    font-size: 1rem;
    font-weight: 700;
}

.sudoku-timer {
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    gap: 0.75rem;
    margin-bottom: 0.85rem;
    padding: 0.85rem 0.95rem;
    border-radius: 18px;
    background: rgba(37, 99, 235, 0.07);
}

.sudoku-timer__label {
    color: var(--sudoku-muted);
    font-size: 0.78rem;
    font-weight: 700;
    letter-spacing: 0.08em;
    text-transform: uppercase;
}

.sudoku-timer__value {
    color: var(--sudoku-ink);
    font-size: 1.35rem;
    font-variant-numeric: tabular-nums;
    letter-spacing: 0.02em;
}

.sudoku-status-card__help {
    margin-bottom: 1rem;
    color: var(--sudoku-muted);
    line-height: 1.55;
}

.sudoku-legend {
    display: grid;
    gap: 0.75rem;
}

.sudoku-legend__item {
    display: inline-flex;
    align-items: center;
    gap: 0.55rem;
    color: var(--sudoku-muted);
    font-size: 0.94rem;
}

.sudoku-swatch {
    width: 0.9rem;
    height: 0.9rem;
    border-radius: 999px;
    display: inline-block;
}

.sudoku-swatch--given { background: var(--sudoku-given); }
.sudoku-swatch--filled { background: var(--sudoku-filled); }
.sudoku-swatch--conflict { background: var(--sudoku-conflict); }
.sudoku-swatch--notes { background: var(--sudoku-accent); }

.sudoku-pad {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 0.65rem;
    margin-top: 0.85rem;
}

.sudoku-pad__button {
    min-height: 58px;
    border: 0;
    border-radius: 18px;
    background: linear-gradient(180deg, rgba(255,255,255,0.98), rgba(226,232,240,0.9));
    color: var(--sudoku-ink);
    font-size: 1.25rem;
    font-weight: 800;
    box-shadow: 0 12px 24px rgba(15, 23, 42, 0.08);
}

.sudoku-pad__button:hover,
.sudoku-pad__button:focus-visible,
.sudoku-cell:hover,
.sudoku-cell:focus-visible {
    outline: none;
    transform: translateY(-1px);
}

.sudoku-pad__button.is-active,
#sudoku-notes[aria-pressed="true"] {
    background: var(--sudoku-accent-soft);
    color: var(--sudoku-accent);
    border-color: rgba(15, 118, 110, 0.2);
}

@media (max-width: 991.98px) {
    .sudoku-hero,
    .sudoku-game {
        grid-template-columns: 1fr;
        flex-direction: column;
    }

    .sudoku-sidepanel {
        width: 100%;
    }

    .sudoku-board {
        width: 100%;
    }
}

@media (max-width: 575.98px) {
    .sudoku-main-card {
        padding: 1rem;
        border-radius: 24px;
    }

    .sudoku-board {
        padding: 0.35rem;
        border-radius: 22px;
    }

    .sudoku-pad__button {
        min-height: 52px;
    }
}