Static Files

The authentication views and templates work, but they look very plain right now. Some CSS can be added to add style to the HTML layout you constructed. The style won’t change, so it’s a static file rather than a template.

Flask automatically adds a static view that takes a path relative to the flaskr/static directory and serves it. The base.html template already has a link to the style.css file:

{{ url_for('static', filename='style.css') }}

Besides CSS, other types of static files might be files with JavaScript functions, or a logo image. They are all placed under the flaskr/static directory and referenced with url_for('static', filename='...').

This tutorial isn’t focused on how to write CSS, so you can just copy the following into the flaskr/static/style.css file:

html { font-family: sans-serif; background: #eee; padding: 1rem; }
body { max-width: 960px; margin: 0 auto; background: white; }
h1 { font-family: serif; color: #377ba8; margin: 1rem 0; }
a { color: #377ba8; }
hr { border: none; border-top: 1px solid lightgray; }
nav { background: lightgray; display: flex; align-items: center; padding: 0 0.5rem; }
nav h1 { flex: auto; margin: 0; }
nav h1 a { text-decoration: none; padding: 0.25rem 0.5rem; }
nav ul  { display: flex; list-style: none; margin: 0; padding: 0; }
nav ul li a, nav ul li span, header .action { display: block; padding: 0.5rem; }
.content { padding: 0 1rem 1rem; }
.content > header { border-bottom: 1px solid lightgray; display: flex; align-items: flex-end; }
.content > header h1 { flex: auto; margin: 1rem 0 0.25rem 0; }
.flash { margin: 1em 0; padding: 1em; background: #cae6f6; border: 1px solid #377ba8; }
.post > header { display: flex; align-items: flex-end; font-size: 0.85em; }
.post > header > div:first-of-type { flex: auto; }
.post > header h1 { font-size: 1.5em; margin-bottom: 0; }
.post .about { color: slategray; font-style: italic; }
.post .body { white-space: pre-line; }
.content:last-child { margin-bottom: 0; }
.content form { margin: 1em 0; display: flex; flex-direction: column; }
.content label { font-weight: bold; margin-bottom: 0.5em; }
.content input, .content textarea { margin-bottom: 1em; }
.content textarea { min-height: 12em; resize: vertical; }
input.danger { color: #cc2f2e; }
input[type=submit] { align-self: start; min-width: 10em; }

You can find a less compact version of style.css in the example code.

Go to and the page should look like the screenshot below.

screenshot of login page

You can read more about CSS from Mozilla’s documentation. If you change a static file, refresh the browser page. If the change doesn’t show up, try clearing your browser’s cache.

Continue to Blog Blueprint.