Cleanup even more global styles (streamlit#9861)

## Describe your changes

This PR removes a couple more unused global styles. These were added and
used a long time ago, but the latest state uses styles defined directly
with the relevant components. This cleanup is related to the advanced
theming project.

## Testing Plan

- No logical or visual changes. 

---

**Contribution License Agreement**

By submitting this pull request you agree that all contributions to this
project are made under the Apache 2.0 license.

Author: lukasmasuch

frontend/lib/src/components/shared/BaseButton/styled-components.ts

@@ -100,6 +100,7 @@ export const StyledBaseButton = styled.button<RequiredBaseButtonProps>(
       minHeight: theme.sizes.minElementHeight,
       margin: theme.spacing.none,
       lineHeight: theme.lineHeights.base,
+      textTransform: "none",
       fontSize: "inherit",
       fontFamily: "inherit",
       color: "inherit",

frontend/lib/src/theme/globalStyles.ts

@@ -19,9 +19,14 @@ import { transparentize } from "color2k"
 
 import { EmotionTheme } from "@streamlit/lib/src/theme"
 
+/**
+ * Contains various styles that are applied globally to the app.
+ *
+ * Please only add styles here if they are truly global. Putting styles to the
+ * individual components should be strongly preferred.
+ */
 export const globalStyles = (theme: EmotionTheme): SerializedStyles => css`
   // Override the base font-size value here.
-  // This overrides the value set in reboot.scss.
   html {
     font-size: ${theme.fontSizes.mdPx}px;
   }
@@ -30,21 +35,13 @@ export const globalStyles = (theme: EmotionTheme): SerializedStyles => css`
   @media print {
     html {
       height: 100%;
-      // make background-colors appear by default (e.g. the sidebar background, widget background, multi-select element background, ...)
+      // make background-colors appear by default (e.g. the sidebar background,
+      // widget background, multi-select element background, ...)
       print-color-adjust: exact;
       -webkit-print-color-adjust: exact;
     }
   }
 
-  // Embedded Overflow Management
-  body.embedded {
-    overflow: hidden;
-  }
-
-  body.embedded:hover {
-    overflow: auto;
-  }
-
   *,
   *::before,
   *::after {
@@ -70,6 +67,15 @@ export const globalStyles = (theme: EmotionTheme): SerializedStyles => css`
     -webkit-font-smoothing: auto;
   }
 
+  // Embedded Overflow Management
+  body.embedded {
+    overflow: hidden;
+  }
+
+  body.embedded:hover {
+    overflow: auto;
+  }
+
   // Future-proof rule: in browsers that support :focus-visible, suppress the focus outline
   // on elements that programmatically receive focus but wouldn't normally show a visible
   // focus outline. In general, this would mean that the outline is only applied if the
@@ -140,31 +146,6 @@ export const globalStyles = (theme: EmotionTheme): SerializedStyles => css`
     vertical-align: middle;
   }
 
-  // Forms
-  //
-  // 1. Allow labels to use margin for spacing.
-
-  label {
-    display: inline-block; // 1
-  }
-
-  // Remove the default border-radius that macOS Chrome adds.
-  // See https://github.com/twbs/bootstrap/issues/24093
-
-  button {
-    // stylelint-disable-next-line property-blacklist
-    border-radius: 0;
-  }
-
-  // Work around a Firefox bug where the transparent button background
-  // results in a loss of the default button focus styles.
-  // Credit https://github.com/suitcss/base/
-
-  button:focus {
-    outline: 1px dotted;
-    outline: 5px auto -webkit-focus-ring-color;
-  }
-
   // 1. Remove the margin in Firefox and Safari
 
   input,
@@ -185,13 +166,6 @@ export const globalStyles = (theme: EmotionTheme): SerializedStyles => css`
     overflow: visible;
   }
 
-  // Remove the inheritance of text transform in Firefox
-
-  button,
-  select {
-    text-transform: none;
-  }
-
   // Set the cursor for all buttons or button-like elements
   button,
   [role="button"] {
@@ -200,13 +174,6 @@ export const globalStyles = (theme: EmotionTheme): SerializedStyles => css`
     }
   }
 
-  // Remove the inheritance of word-wrap in Safari.
-  // See https://github.com/twbs/bootstrap/issues/24990
-
-  select {
-    word-wrap: normal;
-  }
-
   // 1. Prevent a WebKit bug where (2) destroys native audio and video
   //    controls in Android 4.
   // 2. Correct the inability to style clickable types in iOS and Safari.
@@ -219,13 +186,6 @@ export const globalStyles = (theme: EmotionTheme): SerializedStyles => css`
     -webkit-appearance: button; // 2
   }
 
-  // Remove inner border and padding from Firefox, but don't restore the outline like Normalize.
-
-  ::-moz-focus-inner {
-    padding: 0;
-    border-style: none;
-  }
-
   // Hidden attribute
   //
   // Always hide an element with the hidden HTML attribute.