body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f4f4f4;
  }
  /* Styline the Heading of Image Gallery */
  .heading{ 
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 30px;
    background: #121FCF;
    background: linear-gradient(to right, #0e85e0 0%, #26ff1a 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}
/* Styling gallery section where all images are */
  .gallery {
    width: 90%;
    margin:0 auto;
    display:grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    grid-gap: 20px;
    justify-content:center;
    align-items: center;
  }
 
  /* Styling Particular Image */
  .gallery-img {
    width: 200px;
    height: 200px;
    cursor: pointer;
    transition: transform 0.2s;
  }
  /* onHover image will expand little bit */
  .gallery-img:hover {
    transform: scale(1.1);
    cursor: zoom-in;
  }
  /* This section will be seen when we click on image */
  .image-popup-container {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.8);
  }
 
  /* close button when we want to close the bigger image */
  .close-button {
    position: absolute;
    top: 20px;
    right: 50px;
    font-size:60px;
    color: #fff;
    cursor: pointer;
  }
  .close-button:hover{
    color: red;
  }
 
  /* when we click on the image it will expand in bigger size and will displayed
at middle of screen */
  #popupImage {
    display: block;
    max-width: 80%;
    max-height: 80%;
    margin: 0 auto;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
  }
 
  /* Making images more responsive for smaller size device */
  @media (max-width:670px) {
    .gallery{
        grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
        grid-gap: 10px;
    }
    .gallery-img{
        width:150px;
        height: 150px;
    }
 
    .heading{
        font-size: 20px;
    }
  }