.letter-btn {
    padding: 0.6rem 1.2rem;
    border: none;
    background: rgba(0, 200, 255, 0.1);
    color: var(--text-primary);
    border-radius: 25px;
    cursor: pointer;
    font-weight: 500;
    font-size: 1rem;
    min-width: 2.5rem;
    border: 1px solid var(--border-color);
    margin: 0.3rem;
    transition: all 0.3s ease;
}

.letter-btn:hover {
    background: rgba(0, 200, 255, 0.2);
    transform: translateY(-3px);
    box-shadow: 0 0 15px rgba(0, 200, 255, 0.3);
}

.letter-btn.active {
    background: var(--primary-color);
    box-shadow: 0 0 20px rgba(0, 200, 255, 0.4);
}

.no-results {
    text-align: center;
    color: var(--text-secondary);
    font-size: 1.2rem;
    margin: 2rem 0;
    padding: 2rem;
    background: var(--card-bg);
    border-radius: 10px;
    border: 1px solid var(--border-color);
}