Add additional dark mode fixes

I found that my last PR #6 did not address all issues with the dark theme on GItea 1.21, as there were still some unstyled (bright) elements and conflicts with obsolete styling rules.

Changes:
- Corrections on issue and pull request pages: status labels, buttons, timeline items and sidebar spacing
- Highlighting colors in the diff view and code view
- Message box colors
- Modal colors
- Minor corrections of various elements

Let me know if you find any other issues.

Reviewed-on: https://codeberg.org/pat-s/gitea-github-theme/pulls/7
Co-authored-by: Neon <1169307+neon-dev@users.noreply.github.com>
Co-committed-by: Neon <1169307+neon-dev@users.noreply.github.com>

README.md

@@ -2,8 +2,8 @@
 
 **Opinionated** GitHub-based light and dark themes for Gitea including an automatic theme switch option.
 
-Created and tested with Gitea v1.15 - 1.17.
-The theme might work with future versions though Gitea devs might change some CSS classes in the meantime and things might potentially look odd - just try yourself :)
+Tested with Gitea v1.20.
+Older Gitea versions can use previous releases from this repo.
 
 I might update the theme over time to fix oversights and other issues - no guarantee though.
 
@@ -11,7 +11,7 @@ I might update the theme over time to fix oversights and other issues - no guara
 
 1. If you do not have admin access to a Gitea instance, you can use the [Stylus](https://chrome.google.com/webstore/detail/stylus/clngdbkpkpeebahjckkjfobafhncgmne/related) browser extension and use the CSS provided in this repo for the Gitea URL
 2. If you are an admin and want to make this theme available to all users:
-   1. Put `theme-github.css` into `$GITEA_PUBLIC/public/css/theme-github.css` where `$GITEA_PUBLIC` is the "CustomPath" of your instance reported by `gitea help`.
+   1. Put `theme-github.css` into `$GITEA_PUBLIC/public/assets/css/theme-github.css` where `$GITEA_PUBLIC` is the "CustomPath" of your instance reported by `gitea help`.
    2. Add `github` to the comma-separated list in the setting `THEMES` in `app.ini`
    3. Now users can select this theme in their settings under "account"
    4. (optional) If you want to make this theme the default of your instance, set it in `DEFAULT_THEME` in `app.ini`
@@ -37,7 +37,8 @@ If this is somehow possible and I did not managed to get it configured, please l
 
 To use custom themes with the [Gitea helm chart](https://gitea.com/gitea/helm-chart):
 
-1. Create a secret containing the CSS files (here's an example via `terraform`, plain k8s secrets will also work)
+1. Configure the [http](https://registry.terraform.io/providers/hashicorp/http/latest/docs/data-sources/http) provider
+2. Create a secret containing the CSS files (here's an example via `terraform`, plain k8s secrets will also work)
 
 ```hcl
 resource "kubernetes_secret" "gitea-themes" {
@@ -47,16 +48,42 @@ resource "kubernetes_secret" "gitea-themes" {
   }
 
   data = {
-    "theme-github.css"      = "${file("files/gitea/gitea-github-theme-light.css")}"
-    "theme-github-dark.css" = "${file("files/gitea/gitea-github-theme-dark.css")}"
-    "theme-github-auto.css" = "${file("files/gitea/gitea-github-theme-auto.css")}"
+    "theme-github.css"      = data.http.gitea-theme-light.body
+    "theme-github-dark.css" = data.http.gitea-theme-dark.body
+    "theme-github-auto.css" = data.http.gitea-theme-auto.body
   }
 
   type = "Opaque"
 }
+
+
+data "http" "gitea-theme-light" {
+  url = "https://codeberg.org/pat-s/gitea-github-theme/raw/branch/main/theme-github.css"
+
+  request_headers = {
+    Accept = "application/json"
+  }
+}
+
+data "http" "gitea-theme-dark" {
+  url = "https://codeberg.org/pat-s/gitea-github-theme/raw/branch/main/theme-github-dark.css"
+
+  request_headers = {
+    Accept = "application/json"
+  }
+}
+
+data "http" "gitea-theme-auto" {
+  url = "https://codeberg.org/pat-s/gitea-github-theme/raw/branch/main/theme-github-auto.css"
+
+  request_headers = {
+    Accept = "application/json"
+  }
+}
+
 ```
 
-2. Mount the secret via `extraVolumes` in `values.yaml`:
+3. Mount the secret via `extraVolumes` in `values.yaml`:
 
 ```yml
 extraVolumes:
@@ -65,7 +92,7 @@ extraVolumes:
       secretName: gitea-themes
 ```
 
-3. Add the theme options into the config in `values.yaml`:
+4. Add the theme options into the config in `values.yaml`:
 
 ```yml
 gitea: