.base64-encoder-wrapper {
    max-width: 1000px;
    margin: 0 auto;
    padding: 20px;
}

.mode-btn.active {
    background: #667eea !important;
    color: white !important;
}

.example-btn:hover {
    background: #f8fafc;
    border-color: #667eea;
}

textarea:focus {
    outline: none;
    border-color: #667eea;
}

button:hover {
    opacity: 0.9;
    transform: translateY(-1px);
}

button:active {
    transform: translateY(0);
}

@media (max-width: 768px) {
    .mode-selector {
        flex-direction: column;
    }
    
    .mode-btn {
        width: 100%;
    }
}