I've set this image's width property to 100% in css
and save and refreshed the mini browser for many times, but the image was still not 100% to the screen. But after the challenge the teacher writes almost the same code except for class's name and he gets the wanted image size. We were using the same platform. This is way to surreal! I've copied my code below.
<img class="sneaker-image" src="images/sneakers-purple.png" alt="Purple and silver sneakers">
.sneaker-image{
width: 100%;
}