.freq-btn {
    font-size: 1.2rem;
    font-weight: bold;
    padding: 15px 10px;
    border-radius: 12px;
    border: 2px solid var(--glass-border);
    background: transparent;
    color: var(--text-color);
    transition: all 0.2s ease;
}
.freq-btn:hover {
    background: rgba(0, 113, 227, 0.1);
    border-color: var(--btn-primary);
    color: var(--btn-primary);
}
.freq-btn.correct { background: rgba(40, 167, 69, 0.2); border-color: #28a745; color: #28a745; }
.freq-btn.wrong { background: rgba(220, 53, 69, 0.2); border-color: #dc3545; color: #dc3545; }