refactor: rename sign content block shadow to more appropriate name

Author: Antoliny0919

djangosnippets/templates/account/login.html

@@ -5,7 +5,7 @@
 {% block header%}{% endblock %}
 
 {% block content %}
-<div class="w-[40rem] flex flex-col items-center justify-center mx-auto p-8 font-common shadow-sign rounded-lg">
+<div class="w-[40rem] flex flex-col items-center justify-center mx-auto p-8 font-common shadow-sign-content rounded-lg">
     <h3>Sign In</h3>
     <p>Don't have an account? <a class="text-base-green-600 underline">Sign Up</a></p>
     {% include "socialaccount/snippets/login_extra.html" %}

theme/static_src/src/styles.css

@@ -8,7 +8,7 @@
     --color-base-green-400: #256918;
     --color-base-green-600: #1E4F15;
     --color-base-green-800: #12330c;
-    --shadow-sign: rgba(0, 0, 0, 0.24) 0px 3px 8px;
+    --shadow-sign-content: rgba(0, 0, 0, 0.24) 0px 3px 8px;
     --font-header: "Libertinus Sans", sans-serif;
     --font-title: "Playfair Display", sans-serif;
     --font-text: "Nunito", sans-serif;