body {
    margin: 0;
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    font-family: 'Arial', sans-serif;
    background-size: cover;
    background-position: center;
    transition: background-image 1.5s ease-in-out; /* Plynulá zmena obrázka */
}

.container {
    background: rgba(0, 0, 0, 0.6);
    padding: 30px;
    border-radius: 20px;
    color: white;
    text-align: center;
    width: 300px;
    backdrop-filter: blur(5px);
    border: 2px solid rgba(255, 255, 255, 0.2);
}

.controls-group { margin: 20px 0; }

select {
    width: 100%;
    padding: 10px;
    border-radius: 10px;
    background: #444;
    color: white;
    border: none;
}

#music-btn {
    width: 100%;
    padding: 15px;
    border-radius: 10px;
    border: none;
    font-weight: bold;
    cursor: pointer;
    color: white;
    font-size: 1rem;
}

.btn-paused { background-color: #d62828; }
.btn-playing { background-color: #28a745; }

.volume-container { margin-top: 20px; }

input[type="range"] { width: 100%; cursor: pointer; }