> ## Documentation Index
> Fetch the complete documentation index at: https://docs.capsule.new/llms.txt
> Use this file to discover all available pages before exploring further.

# Themes

> Style hosted Capsule apps from Python.

Themes let an app control its hosted shell without leaving Python.

Use them to set the app tagline, logo, accent color, fonts, or one of Capsule's presets.

## Apply a preset

```python theme={null}
app.theme(
    preset="midnight",
    tagline="Support operations, assisted.",
)
```

## Customize colors and fonts

```python theme={null}
app.theme(
    accent="#2563EB",
    font_sans="DM Sans, sans-serif",
    font_mono="DM Mono, monospace",
)
```

## Add a logo

```python theme={null}
app.theme(
    logo="/data/logo.svg",
)
```

If the logo comes from a generated or uploaded file, mount a filesystem and keep the path stable.

## Keep theme close to product definition

Theme belongs near the rest of the app shell:

```python theme={null}
app = cpsl.App(name="support-ops", image=cpsl.Image())

app.theme(
    preset="midnight",
    accent="#2563EB",
    tagline="Inbox triage for support teams.",
)
```

## Related

* [Add Pages](/build/add-pages)
* [Image, Theme, And Deployment Reference](/reference/image-theme-and-deployment)
* [App Styles](/concepts/app-styles)