Use the `no-auto-size` attribute to prevent the dropdown from automatically adjusting its size.

```html
<sd-dropdown no-auto-size open>
  <div class="slot slot--border slot--background flex justify-start" style="height: 110vh; width: 120px;">
    Scroll down
  </div>
  <sd-button slot="trigger">Trigger</sd-button>
</sd-dropdown>
```