/* ══════════════════════════════════════════════
   SUDOKU — Nobel Premium Design
   Haberinyo Game Suite
   ══════════════════════════════════════════════ */

/* ── CSS Variables ── */
:root {
    --sdk-bg: #0f1923;
    --sdk-surface: #1a2332;
    --sdk-surface-light: #243044;
    --sdk-border: rgba(255,255,255,0.08);
    --sdk-border-thick: rgba(255,255,255,0.2);
    --sdk-text: #e8edf3;
    --sdk-text-muted: #8899aa;
    --sdk-given: #ffffff;
    --sdk-user: #64b5f6;
    --sdk-accent: #5c7cfa;
    --sdk-accent-glow: rgba(92,124,250,0.25);
    --sdk-selected: rgba(92,124,250,0.22);
    --sdk-peer: rgba(92,124,250,0.08);
    --sdk-same-val: rgba(92,124,250,0.14);
    --sdk-error-bg: rgba(239,68,68,0.15);
    --sdk-error-text: #f87171;
    --sdk-correct: #22c55e;
    --sdk-pencil: #6b7280;
    --sdk-numpad-bg: #1e2d3d;
    --sdk-numpad-hover: #2a3f52;
    --sdk-numpad-active: #5c7cfa;
    --sdk-radius: 10px;
}

/* ── Page Container ── */
.sudoku-page {
    max-width: 680px;
    margin: 0 auto;
    padding: 20px 12px 40px;
    -webkit-user-select: none;
    user-select: none;
    touch-action: manipulation;
}

/* ── Header ── */
.sudoku-header {
    text-align: center;
    margin-bottom: 20px;
}
.sudoku-header h1 {
    font-family: 'Montserrat', 'Inter', sans-serif;
    font-size: 2.2rem;
    font-weight: 800;
    letter-spacing: 0.08em;
    color: var(--sdk-text);
    margin: 0 0 4px;
    text-shadow: 0 2px 12px rgba(92,124,250,0.15);
}
.sudoku-header p {
    font-family: 'Inter', sans-serif;
    font-size: 0.82rem;
    color: var(--sdk-text-muted);
    margin: 0;
}

/* ── Difficulty Bar ── */
.sudoku-difficulty-bar {
    display: flex;
    justify-content: center;
    gap: 8px;
    margin-bottom: 16px;
}
.sudoku-diff-btn {
    font-family: 'Inter', sans-serif;
    font-size: 0.78rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    padding: 8px 22px;
    border: 1.5px solid var(--sdk-border-thick);
    border-radius: 24px;
    background: transparent;
    color: var(--sdk-text-muted);
    cursor: pointer;
    transition: all 0.2s ease;
}
.sudoku-diff-btn:hover {
    border-color: var(--sdk-accent);
    color: var(--sdk-text);
    background: var(--sdk-accent-glow);
}
.sudoku-diff-btn.active {
    background: var(--sdk-accent);
    border-color: var(--sdk-accent);
    color: #fff;
    box-shadow: 0 4px 18px rgba(92,124,250,0.35);
}

/* ── Status Bar (Timer + Actions) ── */
.sudoku-status-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 12px;
    padding: 0 4px;
}
.sudoku-timer {
    font-family: 'Inter', monospace;
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--sdk-text-muted);
    display: flex;
    align-items: center;
    gap: 6px;
}
.sudoku-timer i {
    font-size: 0.85rem;
    color: var(--sdk-accent);
}
.sudoku-actions {
    display: flex;
    gap: 8px;
}
.sudoku-action-btn {
    font-family: 'Inter', sans-serif;
    font-size: 0.72rem;
    font-weight: 600;
    padding: 6px 14px;
    border: 1px solid var(--sdk-border-thick);
    border-radius: 6px;
    background: transparent;
    color: var(--sdk-text-muted);
    cursor: pointer;
    transition: all 0.15s;
    display: flex;
    align-items: center;
    gap: 5px;
}
.sudoku-action-btn:hover {
    border-color: var(--sdk-accent);
    color: var(--sdk-text);
}
.sudoku-action-btn i { font-size: 0.75rem; }

/* ── Grid Container ── */
.sudoku-grid-wrap {
    display: flex;
    justify-content: center;
    margin-bottom: 18px;
}
.sudoku-grid {
    display: grid;
    grid-template-columns: repeat(9, 1fr);
    grid-template-rows: repeat(9, 1fr);
    border: 2.5px solid var(--sdk-border-thick);
    border-radius: var(--sdk-radius);
    overflow: hidden;
    background: var(--sdk-surface);
    box-shadow:
        0 8px 32px rgba(0,0,0,0.3),
        0 0 0 1px var(--sdk-border),
        inset 0 1px 0 rgba(255,255,255,0.03);
    aspect-ratio: 1;
    max-width: 460px;
    width: 100%;
}

/* ── Cell ── */
.sudoku-cell {
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: 'Inter', sans-serif;
    font-size: 1.35rem;
    font-weight: 700;
    color: var(--sdk-user);
    background: var(--sdk-surface);
    border: 0.5px solid var(--sdk-border);
    cursor: pointer;
    transition: background 0.12s ease;
    aspect-ratio: 1;
    overflow: hidden;
}
.sudoku-cell[data-given="true"] {
    color: var(--sdk-given);
    font-weight: 800;
}

/* 3x3 block borders */
.sudoku-cell:nth-child(3n) { border-right: 2px solid var(--sdk-border-thick); }
.sudoku-cell:nth-child(9n) { border-right: none; }
.sudoku-cell:nth-child(n+19):nth-child(-n+27) { border-bottom: 2px solid var(--sdk-border-thick); }
.sudoku-cell:nth-child(n+46):nth-child(-n+54) { border-bottom: 2px solid var(--sdk-border-thick); }

/* Highlight states */
.sudoku-cell.selected {
    background: var(--sdk-selected) !important;
    box-shadow: inset 0 0 0 2px var(--sdk-accent);
    z-index: 1;
}
.sudoku-cell.peer-highlight {
    background: var(--sdk-peer);
}
.sudoku-cell.same-value {
    background: var(--sdk-same-val);
}
.sudoku-cell.error {
    background: var(--sdk-error-bg) !important;
    color: var(--sdk-error-text) !important;
}
.sudoku-cell.error[data-given="true"] {
    color: var(--sdk-error-text) !important;
}

/* ── Pencil Notes ── */
.sudoku-notes {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    grid-template-rows: repeat(3, 1fr);
    position: absolute;
    inset: 2px;
    pointer-events: none;
}
.sudoku-note {
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.5rem;
    font-weight: 600;
    color: var(--sdk-pencil);
    line-height: 1;
}

/* ── Numpad ── */
.sudoku-numpad {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    margin-bottom: 14px;
}
.sudoku-numpad-row {
    display: flex;
    gap: 6px;
}
.sudoku-num-btn {
    width: 48px;
    height: 52px;
    border: 1.5px solid var(--sdk-border-thick);
    border-radius: 8px;
    background: var(--sdk-numpad-bg);
    color: var(--sdk-text);
    font-family: 'Inter', sans-serif;
    font-size: 1.15rem;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.15s;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
}
.sudoku-num-btn:hover {
    background: var(--sdk-numpad-hover);
    border-color: var(--sdk-accent);
    transform: translateY(-1px);
}
.sudoku-num-btn:active {
    transform: translateY(0);
}
.sudoku-num-btn.completed {
    opacity: 0.3;
    pointer-events: none;
}
.sudoku-num-count {
    position: absolute;
    top: 2px;
    right: 4px;
    font-size: 0.5rem;
    font-weight: 600;
    color: var(--sdk-text-muted);
    line-height: 1;
}

/* ── Tool Buttons Row ── */
.sudoku-tools {
    display: flex;
    justify-content: center;
    gap: 10px;
    margin-bottom: 6px;
}
.sudoku-tool-btn {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 3px;
    padding: 8px 16px;
    border: 1.5px solid var(--sdk-border-thick);
    border-radius: 10px;
    background: transparent;
    color: var(--sdk-text-muted);
    cursor: pointer;
    font-family: 'Inter', sans-serif;
    font-size: 0.65rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    transition: all 0.15s;
    min-width: 56px;
}
.sudoku-tool-btn i {
    font-size: 1rem;
    transition: color 0.15s;
}
.sudoku-tool-btn:hover {
    border-color: var(--sdk-accent);
    color: var(--sdk-text);
}
.sudoku-tool-btn.active {
    border-color: var(--sdk-accent);
    color: var(--sdk-accent);
    background: var(--sdk-accent-glow);
}

/* ── Toast ── */
.sudoku-toast {
    position: fixed;
    top: 80px;
    left: 50%;
    transform: translateX(-50%) translateY(-20px);
    background: #1a1a2e;
    color: #fff;
    font-family: 'Inter', sans-serif;
    font-size: 0.82rem;
    font-weight: 600;
    padding: 10px 24px;
    border-radius: 8px;
    box-shadow: 0 8px 24px rgba(0,0,0,0.5);
    z-index: 10000;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.25s, transform 0.25s;
}
.sudoku-toast.show {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
    pointer-events: auto;
}

/* ── Win Modal ── */
.sudoku-modal-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.65);
    backdrop-filter: blur(6px);
    -webkit-backdrop-filter: blur(6px);
    z-index: 10001;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s;
}
.sudoku-modal-overlay.active {
    opacity: 1;
    pointer-events: auto;
}
.sudoku-modal {
    background: linear-gradient(145deg, #1a2332 0%, #0f1923 100%);
    border: 1px solid rgba(255,255,255,0.1);
    border-radius: 16px;
    padding: 32px 28px;
    max-width: 380px;
    width: 90%;
    text-align: center;
    box-shadow: 0 24px 64px rgba(0,0,0,0.5);
    animation: sdkModalIn 0.4s ease-out;
}
@keyframes sdkModalIn {
    from { transform: scale(0.85) translateY(20px); opacity: 0; }
    to { transform: scale(1) translateY(0); opacity: 1; }
}
.sudoku-modal-emoji {
    font-size: 3rem;
    margin-bottom: 8px;
}
.sudoku-modal-title {
    font-family: 'Inter', sans-serif;
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--sdk-text);
    margin-bottom: 4px;
}
.sudoku-modal-subtitle {
    font-size: 0.82rem;
    color: var(--sdk-text-muted);
    margin-bottom: 16px;
}
.sudoku-modal-stats {
    display: flex;
    justify-content: center;
    gap: 28px;
    margin-bottom: 20px;
}
.sudoku-modal-stat {
    text-align: center;
}
.sudoku-modal-stat-value {
    font-family: 'Inter', monospace;
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--sdk-accent);
}
.sudoku-modal-stat-label {
    font-size: 0.65rem;
    font-weight: 600;
    color: var(--sdk-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.06em;
}
.sudoku-modal-btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 32px;
    border: none;
    border-radius: 10px;
    background: var(--sdk-accent);
    color: #fff;
    font-family: 'Inter', sans-serif;
    font-size: 0.85rem;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.15s;
    box-shadow: 0 4px 18px rgba(92,124,250,0.35);
}
.sudoku-modal-btn:hover {
    transform: translateY(-1px);
    box-shadow: 0 6px 24px rgba(92,124,250,0.45);
}

/* ── Resume Prompt ── */
.sudoku-resume-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.65);
    backdrop-filter: blur(6px);
    -webkit-backdrop-filter: blur(6px);
    z-index: 10002;
    display: flex;
    align-items: center;
    justify-content: center;
}
.sudoku-resume-card {
    background: linear-gradient(145deg, #1a2332 0%, #0f1923 100%);
    border: 1px solid rgba(255,255,255,0.1);
    border-radius: 16px;
    padding: 28px 24px;
    max-width: 340px;
    width: 90%;
    text-align: center;
    box-shadow: 0 24px 64px rgba(0,0,0,0.5);
}
.sudoku-resume-title {
    font-family: 'Inter', sans-serif;
    font-size: 1rem;
    font-weight: 700;
    color: var(--sdk-text);
    margin-bottom: 8px;
}
.sudoku-resume-text {
    font-size: 0.8rem;
    color: var(--sdk-text-muted);
    margin-bottom: 18px;
}
.sudoku-resume-actions {
    display: flex;
    gap: 10px;
    justify-content: center;
}
.sudoku-resume-btn {
    padding: 10px 22px;
    border-radius: 8px;
    font-family: 'Inter', sans-serif;
    font-size: 0.8rem;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.15s;
    border: none;
}
.sudoku-resume-btn.primary {
    background: var(--sdk-accent);
    color: #fff;
    box-shadow: 0 4px 14px rgba(92,124,250,0.3);
}
.sudoku-resume-btn.secondary {
    background: transparent;
    color: var(--sdk-text-muted);
    border: 1.5px solid var(--sdk-border-thick);
}
.sudoku-resume-btn:hover {
    transform: translateY(-1px);
}

/* ── Confetti ── */
@keyframes sdkConfettiFall {
    0%   { transform: translateY(-100vh) rotate(0deg); opacity: 1; }
    100% { transform: translateY(100vh) rotate(720deg); opacity: 0; }
}
.sdk-confetti {
    position: fixed;
    top: 0;
    width: 10px;
    height: 10px;
    z-index: 10003;
    pointer-events: none;
}

/* ── Responsive ── */
@media (max-width: 520px) {
    .sudoku-page { padding: 12px 6px 30px; }
    .sudoku-header h1 { font-size: 1.6rem; }
    .sudoku-grid { max-width: 100%; }
    .sudoku-cell { font-size: 1.1rem; }
    .sudoku-note { font-size: 0.4rem; }
    .sudoku-num-btn {
        width: 36px;
        height: 42px;
        font-size: 1rem;
        border-radius: 6px;
    }
    .sudoku-numpad-row { gap: 4px; }
    .sudoku-diff-btn {
        padding: 6px 14px;
        font-size: 0.7rem;
    }
    .sudoku-tools { gap: 6px; }
    .sudoku-tool-btn {
        padding: 6px 10px;
        min-width: 46px;
        font-size: 0.58rem;
    }
    .sudoku-tool-btn i { font-size: 0.85rem; }
    .sudoku-status-bar { flex-wrap: wrap; gap: 8px; }
    .sudoku-action-btn { font-size: 0.65rem; padding: 5px 10px; }
}

@media (max-width: 380px) {
    .sudoku-cell { font-size: 0.95rem; }
    .sudoku-note { font-size: 0.35rem; }
    .sudoku-num-btn {
        width: 32px;
        height: 38px;
        font-size: 0.9rem;
    }
    .sudoku-diff-btn { padding: 5px 10px; font-size: 0.65rem; }
    .sudoku-tool-btn { padding: 5px 8px; min-width: 40px; }
}