chore: adjusts admin UI styling (#7557)

## Description

- Improves mobile styling of Payload admin UI.
- Reduces font size on dashboard cards.
- Improves the block/collapsible/array field styling.

- [x] I have read and understand the
[CONTRIBUTING.md](https://github.com/payloadcms/payload/blob/main/CONTRIBUTING.md)
document in this repository.

## Type of change

<!-- Please delete options that are not relevant. -->

- [x] Chore (non-breaking change which does not add functionality)

## Checklist:

- [ ] I have added tests that prove my fix is effective or that my
feature works
- [x] Existing test suite passes locally with my changes
- [ ] I have made corresponding changes to the documentation

packages/richtext-slate/src/field/elements/link/LinkDrawer/index.scss

@@ -35,11 +35,11 @@
     height: base(1);
 
     svg {
-      width: base(2.75);
-      height: base(2.75);
+      width: base(2);
+      height: base(2);
       position: relative;
-      left: base(-0.825);
-      top: base(-0.825);
+      inset-inline-start: base(-0.5);
+      top: base(-0.5);
 
       .stroke {
         stroke-width: 2px;

packages/richtext-slate/src/scss/app.scss

@@ -38,19 +38,19 @@
 
   --gutter-h: #{base(3)};
   --spacing-view-bottom: var(--gutter-h);
-  --app-header-height: calc(var(--base) * 3);
-  --doc-controls-height: calc(var(--base) * 3);
+  --doc-controls-height: calc(var(--base) * 2.8);
+  --app-header-height: calc(var(--base) * 2.8);
   --nav-width: 275px;
   --nav-trans-time: 150ms;
 
   @include mid-break {
     --gutter-h: #{base(2)};
-    --app-header-height: calc(var(--base) * 2);
-    --doc-controls-height: calc(var(--base) * 2.5);
+    --app-header-height: calc(var(--base) * 2.4);
+    --doc-controls-height: calc(var(--base) * 2.4);
   }
 
   @include small-break {
-    --gutter-h: #{base(0.5)};
+    --gutter-h: #{base(0.8)};
     --spacing-view-bottom: calc(var(--base) * 2);
     --nav-width: 100vw;
   }

packages/richtext-slate/src/scss/type.scss

@@ -96,6 +96,7 @@
   font-size: $baseline-body-size;
   line-height: $baseline-px;
   font-weight: normal;
+  font-family: var(--font-body);
 }
 
 %code {