Revert "mobile header: tighten layout and fix menu overlay"

This reverts commit 3eac7ca0b6.

mandelstudio/templates/layout.html

@@ -15,8 +15,6 @@
 {{ block.super }}
 {# Ensure Carbasa webshop styling is present so responsive header/footer render correctly. #}
 <link rel="stylesheet" type="text/x-scss" href="{% static 'carbasa/webshop_base.scss' %}">
-{# Project-scoped mobile header fixes (plain CSS; no Bootstrap overrides). #}
-<link rel="stylesheet" href="{% static 'mandelstudio/header_mobile.css' %}">
 {% endblock %}
 
 {% block extrahead %}