.theme-bio { background: linear-gradient(135deg, #e8f5e9 0%, #c8e6c9 100%); }
.theme-bio .game-header h1 { color: #2e7d32; }

.cross-display {
    text-align: center; margin: 15px auto; padding: 20px;
    background: white; border-radius: 16px; max-width: 400px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.08);
}
.cross-parents { font-size: 1.5rem; font-weight: 800; color: #333; font-family: 'Baloo 2', cursive; }
.cross-parents .parent { display: inline-block; padding: 8px 16px; background: #f1f8e9; border-radius: 10px; margin: 0 8px; }
.cross-symbol { font-size: 1.8rem; color: #f44336; vertical-align: middle; }

.punnett-info {
    text-align: center; margin: 10px auto; font-size: 1rem; color: #555;
    font-family: 'Nunito', sans-serif; max-width: 400px;
}

.bio-options {
    display: grid; grid-template-columns: 1fr 1fr; gap: 10px;
    max-width: 400px; margin: 15px auto; padding: 0 15px;
}
.bio-opt {
    padding: 14px 10px; border: 2px solid #c8e6c9; border-radius: 14px;
    background: white; text-align: center; font-size: 1rem;
    font-family: 'Nunito', sans-serif; font-weight: 700; color: #333; cursor: pointer; transition: all 0.2s;
}
.bio-opt:hover { background: #e8f5e9; border-color: #66bb6a; }
.bio-opt.correct { background: #e8f5e9; border-color: #4caf50; color: #2e7d32; }
.bio-opt.wrong { background: #ffebee; border-color: #f44336; color: #c62828; }
.bio-opt.disabled { pointer-events: none; opacity: 0.6; }