Enhancing table borders (#6481)

## What are you changing in this pull request and why?

Makes the table borders thicker for dark and light mode to enhance
readability

(Optional - pending feedback): Make the header background orange to
match our logo

## Checklist
- [ ] I have reviewed the [Content style
guide](https://github.com/dbt-labs/docs.getdbt.com/blob/current/contributing/content-style-guide.md)
so my content adheres to these guidelines.
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have versioned it according to the [version a whole
page](https://github.com/dbt-labs/docs.getdbt.com/blob/current/contributing/single-sourcing-content.md#adding-a-new-version)
and/or [version a block of
content](https://github.com/dbt-labs/docs.getdbt.com/blob/current/contributing/single-sourcing-content.md#versioning-blocks-of-content)
guidelines.
- [ ] I have added checklist item(s) to this list for anything anything
that needs to happen before this PR is merged, such as "needs technical
review" or "change base branch."
- [ ] The content in this PR requires a dbt release note, so I added one
to the [release notes
page](https://docs.getdbt.com/docs/dbt-versions/dbt-cloud-release-notes).
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website/src/css/custom.css

@@ -2112,3 +2112,35 @@ h2.anchor.clicked a.hash-link:before {
     flex-direction: column;
   }
 }
+
+.markdown table th,
+.markdown table td {
+    padding: 8px;
+    border: 1px solid var(--table-border-color);
+    word-wrap: break-word;
+    white-space: normal;
+    text-align: left;
+}
+
+table th {
+  background-color: #ED7254; /* Table header background color */
+}
+
+:root {
+    --table-border-color: #000000; /* Light mode table border color */
+}
+
+/* Dark mode border */
+[data-theme="dark"] {
+    --table-border-color: #ddd; /* Dark mode table border color */
+}
+table th {
+  color: #ffffff; /* White text on lighter background */
+  font-weight: bold;
+}
+
+/* Dark mode table header text */
+[data-theme='dark'] table th {
+  color: #000000; /* Black text on darker background */
+  font-weight: bold;
+}