body {
    font-family: Arial, sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    background-color: #f0f0f0;
}

.container {
    text-align: center;
    position: relative;
}

.slider-track {
    width: 300px;
    height: 10px;
    background: #ddd;
    position: relative;
    margin: 20px 0;
}

#slider-thumb {
    position: absolute;
    width: 20px;
    height: 20px;
    background: blue;
    border-radius: 50%;
    top: -5px;
    left: 0;
    transition: left 0.1s ease;
}

/* Loading icon style */
.loading-icon {
    border: 4px solid #f3f3f3;
    border-top: 4px solid #3498db;
    border-radius: 50%;
    width: 30px;
    height: 30px;
    animation: spin 2s linear infinite;
    margin: 20px auto;
}

.hidden {
    display: none;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}