make navigation and toc primary color

src/qiskit_sphinx_theme/assets/styles/_scaffold.scss

@@ -0,0 +1,22 @@
+/* This code is a Qiskit project.
+ *
+ * (C) Copyright IBM 2024.
+ *
+ * This code is licensed under the Apache License, Version 2.0. You may
+ * obtain a copy of this license in the LICENSE.txt file in the root directory
+ * of this source tree or at http://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Any modifications or derivative works of this code must retain this
+ * copyright notice, and modified files need to carry a notice indicating
+ * that they have been altered from the originals.
+ */
+
+body {
+  // Make navigation and toc icons primary instead of secondary color
+  .toc-overlay-icon,
+  .nav-overlay-icon {
+    .icon {
+      color: var(--color-foreground-primary);
+    }
+  }
+}

src/qiskit_sphinx_theme/assets/styles/qiskit-sphinx-theme.scss

@@ -19,6 +19,7 @@
 @import "icons";
 @import "layout";
 @import "left-sidebar";
+@import "scaffold";
 @import "sphinx-extensions";
 @import "tables";
 @import "typography";