img {
    border-radius: 8px;
}

img {
    border-radius: 50%;
}

img {
    border: 1px solid #ddd;
    border-radius: 4px;
    padding: 5px;
    width: 150px;
}

<img src="paris.jpg" alt="Paris">

img {
    border: 1px solid #ddd;
    border-radius: 4px;
    padding: 5px;
    width: 150px;
}

img:hover {
    box-shadow: 0 0 2px 1px rgba(0, 140, 186, 0.5);
}

<a href="paris.jpg">
  <img src="paris.jpg" alt="Paris">
</a>

img {
    max-width: 100%;
    height: auto;
}

img {
    display: block;
    margin-left: auto;
    margin-right: auto;
    width: 50%;
}

div.polaroid {
    width: 80%;
    background-color: white;
    box-shadow: 0 4px 8px 0 rgba(0, 0, 0, 0.2), 0 6px 20px 0 rgba(0, 0, 0, 0.19);
}

img {width: 100%}

div.container {
    text-align: center;
    padding: 10px 20px;
}

img {
    opacity: 0.5;
    filter: alpha(opacity=50); /* For IE8 and earlier */
}

img {
    -webkit-filter: grayscale(100%); /* Safari 6.0 - 9.0 */
    filter: grayscale(100%);
}

img:hover {
    -webkit-transform: scaleX(-1);
    transform: scaleX(-1);
}

.responsive {
    padding: 0 6px;
    float: left;
    width: 24.99999%;
}

@media only screen and (max-width: 700px){
    .responsive {
        width: 49.99999%;
        margin: 6px 0;
    }
}

@media only screen and (max-width: 500px){
    .responsive {
        width: 100%;
    }
}

// Get the modal
var modal = document.getElementById('myModal');

// Get the image and insert it inside the modal - use its "alt" text as a caption
var img = document.getElementById('myImg');
var modalImg = document.getElementById("img01");
var captionText = document.getElementById("caption");
img.onclick = function(){
    modal.style.display = "block";
    modalImg.src = this.src;
    captionText.innerHTML = this.alt;
}

// Get the  element that closes the modal
var span = document.getElementsByClassName("close")[0];

// When the user clicks on  (x), close the modal
span.onclick = function() {
    modal.style.display = "none";
}