nav-buttons overlap with light/dark theme switch icon in dashboard navbar

[mine-cetinkaya-rundel]

I have:

• searched the issue tracker for similar issues
• installed the latest version of Quarto CLI
• formatted my issue following the Bug Reports guide

Bug description

nav-buttons icons overlap with light/dark theme switch icon in dashboard navbar.

Steps to reproduce

Reprex below:

---
title: "Untitled"
format: 
  dashboard:
    nav-buttons: [linkedin]
theme:
  light: lightly
  dark: darkly
---

Actual behavior

Icons overlap.

Expected behavior

Expected icons to not overlap.

Your environment

IDE: Positron Version: 2025.06.0 (Universal) build 167
Code - OSS Version: 1.100.0
Commit: e7e5d5590adc6bf7b760f837051cd2f57ea9e3dc
Date: 2025-05-29T20:44:08.369Z
Electron: 34.5.1
Chromium: 132.0.6834.210
Node.js: 20.19.0
V8: 13.2.152.41-electron.0
OS: Darwin arm64 24.5.0

Quarto check output

There's an error below, but I don't think it's related to what I'm reporting:

Quarto 1.8.13
[✓] Checking environment information...
      Quarto cache location: /Users/mine/Library/Caches/quarto
[✓] Checking versions of quarto binary dependencies...
      Pandoc version 3.6.3: OK
      Dart Sass version 1.87.0: OK
      Deno version 2.3.1: OK
      Typst version 0.13.0: OK
[✓] Checking versions of quarto dependencies......OK
[✓] Checking Quarto installation......OK
      Version: 1.8.13
      Path: /Applications/quarto/bin

[✓] Checking tools....................OK
      TinyTeX: v2023.08
      Chromium: (not installed)

[✓] Checking LaTeX....................OK
      Using: TinyTex
      Path: /Users/mine/Library/TinyTeX/bin/universal-darwin
      Version: 2024

[✓] Checking Chrome Headless....................OK
      Using: Chrome found on system
      Path: /Applications/Google Chrome.app/Contents/MacOS/Google Chrome
      Source: MacOS known location

[✓] Checking basic markdown render....OK

[✓] Checking Python 3 installation....OK
      Version: 3.12.6
      Path: /opt/homebrew/opt/python@3.12/bin/python3.12
      Jupyter: 5.7.2
      Kernels: python3

(|) Checking Jupyter engine render....
ERROR: Error executing '/opt/homebrew/opt/python@3.12/bin/python3.12': Broken pipe (os error 32)
WARN: Should not have arrived here:
[✓] Checking Jupyter engine render....OK

ERROR: [non-error-thrown] undefined

Stack trace:
    at _Command.handleError (file:///Applications/quarto/bin/quarto.js:10025:117)
    at _Command.parseCommand (file:///Applications/quarto/bin/quarto.js:9712:12)
    at eventLoopTick (ext:core/01_core.js:178:7)
    at async quarto (file:///Applications/quarto/bin/quarto.js:170893:5)
    at async file:///Applications/quarto/bin/quarto.js:170921:5
    at async file:///Applications/quarto/bin/quarto.js:170776:14
    at async mainRunner (file:///Applications/quarto/bin/quarto.js:170778:5)
    at async file:///Applications/quarto/bin/quarto.js:170914:3