/* Racer — Amber Asphalt Theme */
:root {
    --rc-accent: #F59E0B;
    --rc-accent-light: #FBBF24;
    --rc-accent-dark: #B45309;
    --rc-glow: rgba(251, 191, 36, 0.55);
    --rc-bg: #0F0D08;
    --rc-surface: #1C1810;
    --rc-surface-light: #2B2418;
    --rc-text: #FAF4E6;
    --rc-text-dim: #B0A088;
    --rc-border: #3A2F1E;
    --rc-success: #34D399;
    --rc-gold: #FACC15;
    --rc-danger: #F87171;
}

.rc-layout {
    display: flex;
    justify-content: center;
    gap: 20px;
    max-width: 1200px;
    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(--rc-surface);
    border: 1px dashed var(--rc-text-dim);
    display: flex; align-items: center; justify-content: center;
    color: var(--rc-text-dim); font-size: 12px; border-radius: 8px;
}

#racer-app {
    flex: 1;
    max-width: 720px;
    min-width: 320px;
    color: var(--rc-text);
}

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

/* Header */
.rc-header { text-align: center; padding: 36px 0 20px; }
.rc-logo-mark {
    width: 60px; height: 60px;
    background: var(--rc-surface);
    border-radius: 50%;
    border: 1.5px solid var(--rc-border);
    display: inline-flex; align-items: center; justify-content: center;
    margin-bottom: 12px;
    box-shadow: 0 0 24px var(--rc-glow);
}
.rc-flag {
    width: 28px; height: 28px;
    background:
        conic-gradient(#fff 0 25%, #000 0 50%, #fff 0 75%, #000 0 100%);
    border-radius: 4px;
}
.rc-header h1 {
    font-family: 'Syne', sans-serif;
    font-size: 2.6rem;
    font-weight: 800;
    color: var(--rc-accent-light);
    letter-spacing: 6px;
    margin: 0;
    text-shadow: 0 0 26px var(--rc-glow);
}
.subtitle { color: var(--rc-text-dim); margin-top: 8px; }

/* Cards */
.card {
    background: var(--rc-surface);
    border-radius: 14px;
    padding: 20px;
    margin-bottom: 16px;
    border: 1px solid var(--rc-border);
}
.card__title {
    font-family: 'Syne', sans-serif;
    font-size: 0.85rem;
    text-transform: uppercase;
    letter-spacing: 2px;
    color: var(--rc-accent-light);
    margin-bottom: 14px;
}
.difficulty-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 10px;
}
.diff-btn {
    background: var(--rc-surface-light);
    border: 1.5px solid transparent;
    color: var(--rc-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: 0.85rem;
}
.diff-btn:hover { transform: translateY(-2px); border-color: var(--rc-accent); }
.diff-btn.selected {
    background: linear-gradient(135deg, var(--rc-accent-dark), var(--rc-accent));
    border-color: var(--rc-accent-light);
    box-shadow: 0 0 16px var(--rc-glow);
}
.diff-icon {
    font-family: 'JetBrains Mono', monospace;
    font-weight: 700;
    color: var(--rc-accent-light);
}
.diff-btn.selected .diff-icon { color: #fff; }
.diff-desc { font-size: 0.72rem; color: var(--rc-text-dim); }
.diff-btn.selected .diff-desc { color: rgba(255,255,255,0.85); }

.rc-rules {
    margin: 0; padding-left: 1.1rem;
    color: var(--rc-text-dim);
    font-size: 0.92rem; line-height: 1.6;
}
.rc-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(--rc-accent), var(--rc-accent-light));
    color: #1A1207;
    box-shadow: 0 6px 18px rgba(245, 158, 11, 0.35);
}
.btn--outline {
    background: transparent;
    border: 1.5px solid var(--rc-accent);
    color: var(--rc-accent-light);
}
.btn--outline:hover { background: rgba(245, 158, 11, 0.12); }
.btn--ghost { background: transparent; color: var(--rc-text-dim); }
.btn--ghost:hover { color: var(--rc-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(--rc-surface);
    padding: 14px;
    border-radius: 12px;
    border: 1px solid var(--rc-border);
    margin-bottom: 12px;
}
.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(--rc-text-dim);
}
.hud__value {
    font-family: 'JetBrains Mono', monospace;
    font-size: 1.4rem; font-weight: 700;
    color: var(--rc-accent-light);
}
.hud__timer { color: var(--rc-gold); }

/* Canvas */
.rc-canvas-wrap {
    display: flex; justify-content: center;
    padding: 8px 0;
}
#rc-canvas {
    width: 100%; max-width: 640px;
    aspect-ratio: 4 / 3;
    height: auto;
    background: #1a3a0c;
    border-radius: 12px;
    border: 1px solid var(--rc-border);
    box-shadow: 0 12px 36px rgba(0,0,0,0.5);
    display: block;
    touch-action: none;
}

/* Touch */
.rc-touch {
    display: none;
    margin-top: 10px;
    justify-content: space-between;
    gap: 8px;
}
.touch-btn {
    flex: 1;
    background: var(--rc-surface);
    border: 1.5px solid var(--rc-border);
    color: var(--rc-accent-light);
    padding: 18px 0;
    border-radius: 12px;
    font-size: 1.4rem;
    font-weight: 700;
    user-select: none;
    touch-action: manipulation;
}
.touch-btn:active { background: var(--rc-accent-dark); color: #fff; }

.rc-actions {
    display: flex; justify-content: center; margin-top: 12px;
}

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

.lb-card h2 {
    font-family: 'Syne', sans-serif;
    color: var(--rc-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(--rc-bg);
    margin-bottom: 6px;
    border-radius: 8px;
    border: 1px solid var(--rc-border);
    font-family: 'DM Sans', sans-serif;
}
#leaderboard-list li::before {
    content: counter(lb);
    color: var(--rc-accent-light);
    font-weight: 700; margin-right: 10px; min-width: 24px;
}
#leaderboard-list li:nth-child(1) { border-color: var(--rc-gold); }
#leaderboard-list li:nth-child(1)::before { color: var(--rc-gold); }
#leaderboard-list .lb-score {
    font-family: 'JetBrains Mono', monospace;
    color: var(--rc-accent-light); font-weight: 600;
}

/* Responsive */
@media (max-width: 900px) {
    .rc-layout { flex-direction: column; padding: 12px; }
    .ad-slot { width: 100%; }
    .ad-placeholder--vertical { width: 100%; height: 90px; }
    .difficulty-grid { grid-template-columns: repeat(3, 1fr); font-size: 0.75rem; }
    .rc-header h1 { font-size: 2rem; letter-spacing: 3px; }
    .rc-touch { display: flex; }
    #game-hud { grid-template-columns: repeat(2, 1fr); }
}