Images in a flexbox don't resize if I make them links

I have a flexbox of three square images, which I want to adjust to the size of the browser window as I narrow or widen it. I've managed to do this. However, I would like each image to be a link. When I try to do this, the images don't grow or shrink anymore.

This is the code where the images are not links, and the pictures resize as I want them to:

HTML:

<div class="container"><img src="001.jpg"><img src="002.jpg"><img src="003.jpg"></div>

CSS:

.container {  margin: auto;  display: flex;  flex-flow: row wrap;  justify-content: center;}.container img {  overflow: hidden;  flex: 1 1 400px}

I've tried for instance:

<a href="website.html"><img src="001.jpg"></a>

And change the second part of the CSS to

.container a

instead of

.container img

But this, or other solutions that I've tried don't work, as the images don't grow or shrink when I change the window size.