Make some improvements to docs style

LICENSE-THIRD-PARTY.txt

@@ -15,6 +15,7 @@ Applies to:
         - .github/workflows/fragment-check.yml: Entire file
         - .github/workflows/prepare-release.yml: Workflow heavily inspired by original
         - .github/scripts/normalize_coverage.py: Entire file
+        - docs/_static/extra.css: Entire file
 ---------------------------------------------------------------------------------------------------
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

docs/_static/extra.css

@@ -0,0 +1,47 @@
+html {
+    word-wrap: anywhere;
+}
+
+body {
+    --toc-item-spacing-horizontal: 0.5rem;
+    --admonition-font-size: 0.8em;
+}
+
+.icon {
+    user-select: none;
+}
+
+.viewcode-back {
+    position: absolute;
+    right: 1em;
+    background-color: var(--color-code-background);
+    width: auto;
+}
+
+.toc-drawer {
+    width: initial;
+    max-width: 20em;
+    right: -20em;
+}
+
+.toc-tree ul ul ul ul {
+    border-left: 1px solid var(--color-background-border);
+}
+
+@media (max-width: 82em) {
+    body {
+        font-size: 0.7em;
+    }
+
+    .toc-tree {
+        padding-left: 0;
+    }
+
+    .sidebar-brand-text {
+        font-size: 1rem;
+    }
+
+    .sidebar-tree .reference {
+        padding: 0.5em 1em;
+    }
+}

docs/conf.py

@@ -94,6 +94,9 @@
 html_theme = "furo"
 html_favicon = "https://i.imgur.com/nPCcxts.png"
 
+html_static_path = ["_static"]
+html_css_files = ["extra.css"]
+
 # -- Extension configuration -------------------------------------------------
 
 # Third-party projects documentation references: