/* ── Gomoku — Warm Amber Goban ── */
:root {
    --gmk-accent: #92400E;
    --gmk-accent-light: #F59E0B;
    --gmk-accent-dark: #451A03;
    --gmk-glow: rgba(245, 158, 11, 0.45);
    --gmk-bg: #1F1208;
    --gmk-board: #D4A574;
    --gmk-board-dark: #8B5E2D;
    --gmk-line: rgba(0,0,0,0.55);
    --gmk-surface: #2C1A0C;
    --gmk-surface-light: #3D2614;
    --gmk-text: #FEF3C7;
    --gmk-text-dim: #C7A36B;
    --gmk-black: #0F0F0F;
    --gmk-white: #F8FAFC;
    --gmk-gold: #FDE047;
    --gmk-success: #4ADE80;
    --gmk-danger: #F87171;
}

/* ── Layout ── */
.gmk-layout {
    display: flex;
    justify-content: center;
    gap: 20px;
    max-width: 1400px;
    margin: 0 auto;
    padding: 20px;
    min-height: calc(100vh - 80px);
}
.ad-slot { width: 160px; flex-shrink: 0; }
.ad-slot--left, .ad-slot--right { display: flex; align-items: flex-start; }
.ad-placeholder--vertical {
    width: 160px; height: 600px;
    background: var(--gmk-surface);
    border: 1px dashed var(--gmk-text-dim);
    display: flex; align-items: center; justify-content: center;
    color: var(--gmk-text-dim); font-size: 12px; border-radius: 8px;
}

#gomoku-app {
    flex: 1;
    max-width: 740px;
    min-width: 320px;
    color: var(--gmk-text);
}

/* ── Screens ── */
.screen { display: none; }
.screen.active { display: block; animation: gmkFade 0.3s ease; }
@keyframes gmkFade {
    from { opacity: 0; transform: translateY(8px); }
    to { opacity: 1; transform: translateY(0); }
}

/* ── Header ── */
.gmk-header {
    text-align: center;
    padding: 36px 0 24px;
}
.gmk-logo { margin-bottom: 16px; }
.gmk-logo-board {
    display: inline-flex;
    gap: 6px;
    padding: 12px 16px;
    background: var(--gmk-board);
    background-image:
        repeating-linear-gradient(0deg, var(--gmk-line) 0, var(--gmk-line) 1px, transparent 1px, transparent 14px),
        repeating-linear-gradient(90deg, var(--gmk-line) 0, var(--gmk-line) 1px, transparent 1px, transparent 14px);
    border-radius: 10px;
    border: 1px solid var(--gmk-accent-dark);
    box-shadow: 0 8px 20px rgba(0,0,0,0.4);
}
.gmk-mini-stone {
    width: 22px; height: 22px;
    border-radius: 50%;
    box-shadow: inset -2px -2px 4px rgba(0,0,0,0.4), 0 2px 4px rgba(0,0,0,0.3);
}
.gmk-mini-stone.black { background: radial-gradient(circle at 30% 30%, #555, #0a0a0a); }
.gmk-mini-stone.white { background: radial-gradient(circle at 30% 30%, #fff, #ccc); }
.gmk-header h1 {
    font-family: 'Syne', sans-serif;
    font-size: 2.4rem;
    font-weight: 800;
    color: var(--gmk-accent-light);
    letter-spacing: 4px;
    margin: 12px 0 0;
    text-shadow: 0 0 24px var(--gmk-glow);
}
.subtitle {
    color: var(--gmk-text-dim);
    font-size: 1rem;
    margin-top: 8px;
}

/* ── Cards ── */
.card {
    background: var(--gmk-surface);
    border-radius: 14px;
    padding: 20px;
    margin-bottom: 16px;
    border: 1px solid var(--gmk-surface-light);
}
.card__title {
    font-family: 'Syne', sans-serif;
    font-size: 0.85rem;
    text-transform: uppercase;
    letter-spacing: 2px;
    color: var(--gmk-accent-light);
    margin-bottom: 14px;
}

/* ── Difficulty ── */
.difficulty-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 10px;
}
.diff-btn {
    background: var(--gmk-surface-light);
    border: 1.5px solid transparent;
    color: var(--gmk-text);
    padding: 14px 8px;
    border-radius: 10px;
    cursor: pointer;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
    transition: transform 0.15s ease, border-color 0.15s ease;
    font-family: 'DM Sans', sans-serif;
    font-size: 0.9rem;
}
.diff-btn:hover { transform: translateY(-2px); border-color: var(--gmk-accent-light); }
.diff-btn.selected {
    background: linear-gradient(135deg, var(--gmk-accent-dark), var(--gmk-accent));
    border-color: var(--gmk-accent-light);
    box-shadow: 0 0 16px rgba(245, 158, 11, 0.3);
}
.diff-icon {
    font-family: 'JetBrains Mono', monospace;
    font-size: 1.2rem;
    color: var(--gmk-gold);
}
.diff-desc { font-size: 0.72rem; color: var(--gmk-text-dim); }
.diff-btn.selected .diff-desc { color: rgba(255,255,255,0.85); }

/* Toggle */
.gmk-toggle {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 8px 0;
    color: var(--gmk-text);
    font-family: 'DM Sans', sans-serif;
    font-size: 0.9rem;
    cursor: pointer;
}
.gmk-toggle input { accent-color: var(--gmk-accent-light); transform: scale(1.2); }

/* Rules */
.gmk-rules {
    margin: 0;
    padding-left: 1.1rem;
    color: var(--gmk-text-dim);
    font-size: 0.92rem;
    line-height: 1.7;
}
.gmk-rules li + li { margin-top: 6px; }

/* ── Buttons ── */
.btn {
    font-family: 'DM Sans', sans-serif;
    font-weight: 600;
    border-radius: 10px;
    border: none;
    cursor: pointer;
    padding: 12px 22px;
    transition: transform 0.12s ease, box-shadow 0.12s ease;
    font-size: 0.95rem;
}
.btn:hover { transform: translateY(-1px); }
.btn--primary {
    background: linear-gradient(135deg, var(--gmk-accent), var(--gmk-accent-light));
    color: #fff;
    box-shadow: 0 6px 18px rgba(146, 64, 14, 0.45);
}
.btn--outline {
    background: transparent;
    border: 1.5px solid var(--gmk-accent-light);
    color: var(--gmk-accent-light);
}
.btn--outline:hover { background: rgba(245,158,11,0.12); }
.btn--ghost { background: transparent; color: var(--gmk-text-dim); }
.btn--ghost:hover { color: var(--gmk-accent-light); }
.btn--lg { padding: 16px 36px; font-size: 1.05rem; }
.btn--sm { padding: 8px 14px; font-size: 0.85rem; }

.menu-actions {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    margin-top: 18px;
}

/* HUD */
#game-hud {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 10px;
    background: var(--gmk-surface);
    padding: 14px;
    border-radius: 12px;
    border: 1px solid var(--gmk-surface-light);
    margin-bottom: 18px;
}
.hud__cell { display: flex; flex-direction: column; align-items: center; gap: 2px; }
.hud__label { font-size: 0.7rem; text-transform: uppercase; letter-spacing: 1.5px; color: var(--gmk-text-dim); }
.hud__value {
    font-family: 'JetBrains Mono', monospace;
    font-size: 1.4rem;
    font-weight: 700;
    color: var(--gmk-accent-light);
}
.hud__timer { color: var(--gmk-gold); }

/* Board */
.gmk-board-wrap {
    position: relative;
    display: flex;
    justify-content: center;
    padding: 14px 0;
}
#gmk-board {
    width: 100%;
    max-width: 600px;
    aspect-ratio: 1;
    background: var(--gmk-board);
    background-image: radial-gradient(ellipse at center, #E6BC85 0%, var(--gmk-board) 70%);
    border-radius: 12px;
    border: 2px solid var(--gmk-accent-dark);
    box-shadow: 0 12px 30px rgba(0,0,0,0.5);
    cursor: pointer;
    touch-action: none;
}
.gmk-status {
    position: absolute;
    top: 20px; right: 20px;
    padding: 8px 14px;
    background: rgba(0,0,0,0.6);
    color: var(--gmk-gold);
    border-radius: 8px;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.85rem;
    pointer-events: none;
    opacity: 0;
    transition: opacity 0.3s;
}
.gmk-status.show { opacity: 1; }

.gmk-actions {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 10px;
    margin-top: 18px;
}

/* Result */
.result-card, .lb-card {
    background: var(--gmk-surface);
    border-radius: 16px;
    padding: 36px 28px;
    border: 1px solid var(--gmk-surface-light);
    text-align: center;
    max-width: 480px;
    margin: 40px auto;
    box-shadow: 0 18px 36px rgba(0,0,0,0.4);
}
.result-card h2 {
    font-family: 'Syne', sans-serif;
    font-size: 2rem;
    color: var(--gmk-accent-light);
    letter-spacing: 4px;
    margin: 0 0 12px;
}
.result-score {
    font-family: 'JetBrains Mono', monospace;
    font-size: 3rem;
    font-weight: 700;
    color: var(--gmk-gold);
    margin: 8px 0;
}
.result-detail { color: var(--gmk-text-dim); font-size: 0.95rem; margin-bottom: 18px; line-height: 1.6; }
#nickname {
    width: 100%;
    padding: 12px 14px;
    border-radius: 10px;
    background: var(--gmk-bg);
    color: var(--gmk-text);
    border: 1.5px solid var(--gmk-surface-light);
    font-family: 'DM Sans', sans-serif;
    font-size: 0.95rem;
    margin-bottom: 12px;
    box-sizing: border-box;
}
#nickname:focus { outline: none; border-color: var(--gmk-accent-light); }
.result-actions { display: flex; gap: 10px; justify-content: center; margin-bottom: 10px; }

.lb-card h2 {
    font-family: 'Syne', sans-serif;
    color: var(--gmk-accent-light);
    letter-spacing: 4px;
    margin-bottom: 18px;
}
#leaderboard-list { list-style: none; padding: 0; margin: 0 0 16px; text-align: left; counter-reset: lb; }
#leaderboard-list li {
    counter-increment: lb;
    display: flex; justify-content: space-between;
    padding: 10px 14px;
    background: var(--gmk-bg);
    margin-bottom: 6px;
    border-radius: 8px;
    border: 1px solid var(--gmk-surface-light);
    font-family: 'DM Sans', sans-serif;
}
#leaderboard-list li::before {
    content: counter(lb);
    color: var(--gmk-accent-light);
    font-weight: 700;
    margin-right: 10px;
    min-width: 24px;
}
#leaderboard-list li:nth-child(1) { border-color: var(--gmk-gold); }
#leaderboard-list li:nth-child(1)::before { color: var(--gmk-gold); }
.lb-score { font-family: 'JetBrains Mono', monospace; color: var(--gmk-accent-light); font-weight: 600; }

/* Responsive */
@media (max-width: 900px) {
    .gmk-layout { flex-direction: column; padding: 12px; }
    .ad-slot { width: 100%; }
    .ad-placeholder--vertical { width: 100%; height: 90px; }
    .gmk-header h1 { font-size: 1.8rem; letter-spacing: 2px; }
    .difficulty-grid { grid-template-columns: repeat(3, 1fr); }
    #game-hud { grid-template-columns: repeat(2, 1fr); }
}