/* ============================================================
   Sudoku — Zen Ink Theme
   Accent: #14b8a6 (teal)   Ink: #0f766e
   Font: Syne (display) · DM Sans (body) · JetBrains Mono (data)
   ============================================================ */

/* ── Sudoku Layout (3-column) ── */
.sk-layout {
    display: grid;
    grid-template-areas:
        "top top top"
        "left game right"
        "bottom bottom bottom";
    grid-template-columns: 160px 1fr 160px;
    grid-template-rows: auto 1fr auto;
    min-height: 100vh;
    background: #0a0f0e;
    color: #ccd6f6;
    font-family: 'DM Sans', -apple-system, BlinkMacSystemFont, sans-serif;
}
.sk-layout .ad-slot--top    { grid-area: top; }
.sk-layout .ad-slot--left   { grid-area: left; }
.sk-layout .ad-slot--right  { grid-area: right; }
.sk-layout .ad-slot--bottom { grid-area: bottom; }

#sk-app {
    grid-area: game;
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 16px 0 24px;
    gap: 14px;
    max-width: 500px;
    margin: 0 auto;
    width: 100%;
}

/* ── Header ── */
.sk-header {
    text-align: center;
    width: 100%;
}

.sk-title {
    font-family: 'Syne', sans-serif;
    font-size: 1.6rem;
    font-weight: 800;
    letter-spacing: 0.04em;
    color: #e2e8f0;
    margin: 0 0 8px;
}

.sk-info-bar {
    display: flex;
    justify-content: center;
    gap: 24px;
    padding: 8px 16px;
    background: rgba(255,255,255,0.04);
    border: 1px solid rgba(255,255,255,0.08);
    border-radius: 10px;
    backdrop-filter: blur(8px);
}

.sk-info-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 2px;
}

.sk-info-label {
    font-size: 0.65rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: #8892b0;
}

.sk-info-value {
    font-size: 1.05rem;
    font-weight: 700;
    color: #14b8a6;
}

.sk-timer {
    font-variant-numeric: tabular-nums;
    font-family: 'JetBrains Mono', 'Courier New', monospace;
}

/* ── Canvas ── */
.sk-canvas-wrap {
    position: relative;
    line-height: 0;
    border: 2px solid rgba(20,184,166,0.15);
    border-radius: 8px;
    box-shadow: 0 0 40px rgba(20,184,166,0.08), 0 4px 24px rgba(0,0,0,0.4);
    overflow: hidden;
}

#sudokuCanvas {
    display: block;
    background: #0f1523;
    cursor: pointer;
    touch-action: none;
    max-width: 100%;
    height: auto;
}

/* ── Number Pad ── */
.sk-controls {
    width: 100%;
    max-width: 450px;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.sk-numpad {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 6px;
}

.sk-num-btn {
    padding: 12px 0;
    font-size: 1.2rem;
    font-weight: 700;
    color: #e2e8f0;
    background: rgba(255,255,255,0.06);
    border: 1px solid rgba(255,255,255,0.1);
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.15s ease;
    user-select: none;
    -webkit-tap-highlight-color: transparent;
}

.sk-num-btn:hover {
    background: rgba(20,184,166,0.12);
    border-color: rgba(20,184,166,0.3);
    color: #14b8a6;
}

.sk-num-btn:active {
    transform: scale(0.94);
    background: rgba(20,184,166,0.2);
}

.sk-num-btn.active {
    background: rgba(20,184,166,0.18);
    border-color: #14b8a6;
    color: #14b8a6;
    box-shadow: 0 0 12px rgba(20,184,166,0.2);
}

.sk-num-btn.completed {
    opacity: 0.35;
    pointer-events: none;
}

.sk-erase-btn {
    font-size: 1.3rem;
}

/* ── Action Buttons ── */
.sk-action-row {
    display: flex;
    gap: 6px;
}

.sk-action-btn {
    flex: 1;
    padding: 10px 8px;
    font-size: 0.8rem;
    font-weight: 600;
    color: #a8b2d1;
    background: rgba(255,255,255,0.04);
    border: 1px solid rgba(255,255,255,0.08);
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.15s ease;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 3px;
    user-select: none;
    -webkit-tap-highlight-color: transparent;
}

.sk-action-btn:hover {
    background: rgba(255,255,255,0.08);
    color: #e2e8f0;
}

.sk-action-btn:active {
    transform: scale(0.96);
}

.sk-action-btn.active {
    background: rgba(20,184,166,0.12);
    border-color: rgba(20,184,166,0.3);
    color: #14b8a6;
}

.sk-action-btn--primary {
    background: rgba(20,184,166,0.1);
    border-color: rgba(20,184,166,0.25);
    color: #14b8a6;
}

.sk-action-btn--primary:hover {
    background: rgba(20,184,166,0.2);
    border-color: rgba(20,184,166,0.4);
}

.sk-btn-icon {
    font-size: 1.1rem;
}

/* ── Game Row ── */
.sk-game-row {
    display: flex;
    gap: 8px;
}

.sk-select {
    flex: 1;
    padding: 10px 12px;
    font-size: 0.85rem;
    font-weight: 600;
    color: #a8b2d1;
    background: rgba(255,255,255,0.04);
    border: 1px solid rgba(255,255,255,0.08);
    border-radius: 8px;
    cursor: pointer;
    appearance: none;
    -webkit-appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%238892b0' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 12px center;
    padding-right: 32px;
}

.sk-select option {
    background: #1a1f35;
    color: #ccd6f6;
}

/* ── Volume ── */
.sk-volume-control {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 4px 12px;
    background: rgba(255,255,255,0.04);
    border: 1px solid rgba(255,255,255,0.08);
    border-radius: 8px;
    font-size: 0.75rem;
    color: #8892b0;
}

.sk-volume-control input[type="range"] {
    width: 80px;
    accent-color: #14b8a6;
}

/* ── Overlay ── */
.sk-overlay {
    position: fixed;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(0,0,0,0.75);
    backdrop-filter: blur(6px);
    z-index: 1000;
    animation: sk-fadeIn 0.3s ease;
}

.sk-overlay.hidden {
    display: none;
}

@keyframes sk-fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.sk-overlay-card {
    background: linear-gradient(135deg, #1a1f35 0%, #0f1523 100%);
    border: 1px solid rgba(20,184,166,0.2);
    border-radius: 16px;
    padding: 32px 28px;
    max-width: 380px;
    width: 90%;
    text-align: center;
    box-shadow: 0 20px 60px rgba(0,0,0,0.5);
    animation: sk-slideUp 0.4s ease;
}

@keyframes sk-slideUp {
    from { transform: translateY(30px); opacity: 0; }
    to { transform: translateY(0); opacity: 1; }
}

.sk-overlay-title {
    font-family: 'Syne', sans-serif;
    font-size: 1.6rem;
    font-weight: 800;
    color: #14b8a6;
    margin: 0 0 4px;
}

.sk-overlay-subtitle {
    font-size: 0.9rem;
    color: #8892b0;
    margin: 0 0 20px;
}

.sk-overlay-stats {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-bottom: 20px;
}

.sk-stat {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
}

.sk-stat-label {
    font-size: 0.65rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: #8892b0;
}

.sk-stat-value {
    font-size: 1.1rem;
    font-weight: 700;
    color: #14b8a6;
}

.sk-nickname-row {
    margin-bottom: 16px;
}

.sk-nickname-row input {
    width: 100%;
    padding: 10px 14px;
    font-size: 0.9rem;
    color: #e2e8f0;
    background: rgba(255,255,255,0.06);
    border: 1px solid rgba(255,255,255,0.12);
    border-radius: 8px;
    outline: none;
    transition: border-color 0.2s;
    box-sizing: border-box;
}

.sk-nickname-row input:focus {
    border-color: #14b8a6;
}

.sk-overlay-btns {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.sk-obtn {
    padding: 12px 16px;
    font-size: 0.9rem;
    font-weight: 600;
    border: 1px solid transparent;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.15s ease;
    user-select: none;
}

.sk-obtn--primary {
    background: linear-gradient(135deg, #14b8a6 0%, #4ecdc4 100%);
    color: #0a0f0e;
}

.sk-obtn--primary:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 16px rgba(20,184,166,0.3);
}

.sk-obtn--secondary {
    background: rgba(255,255,255,0.08);
    color: #e2e8f0;
    border-color: rgba(255,255,255,0.12);
}

.sk-obtn--secondary:hover {
    background: rgba(255,255,255,0.12);
}

.sk-obtn--ghost {
    background: transparent;
    color: #8892b0;
}

.sk-obtn--ghost:hover {
    color: #e2e8f0;
}

/* ── Ad slots ── */
.ad-slot { display: flex; align-items: center; justify-content: center; }
.ad-placeholder {
    padding: 8px 16px;
    font-size: 0.7rem;
    color: #4a5568;
    border: 1px dashed rgba(255,255,255,0.06);
    border-radius: 4px;
}
.ad-placeholder--vertical {
    writing-mode: vertical-rl;
    height: 300px;
}

/* ── Responsive ── */
@media (max-width: 900px) {
    .sk-layout {
        grid-template-areas:
            "top"
            "game"
            "bottom";
        grid-template-columns: 1fr;
        grid-template-rows: auto 1fr auto;
    }
    .sk-layout .ad-slot--left,
    .sk-layout .ad-slot--right { display: none; }

    #sk-app { padding: 12px 16px 20px; }
}

@media (max-width: 480px) {
    #sudokuCanvas {
        width: 100%;
        height: auto;
    }
    .sk-numpad { gap: 4px; }
    .sk-num-btn { padding: 10px 0; font-size: 1.05rem; }
    .sk-action-btn { font-size: 0.7rem; padding: 8px 4px; }
}