Add form styles and update button classes for consistency

- Introduced a new CSS file for form styles (forms.css) to enhance form layout and design.
- Removed deprecated button styles from imports.css and updated button classes across templates to use the new utility classes.
- Updated various templates to reflect the new button styles, ensuring a consistent look and feel throughout the application.
- Refactored form-related styles in main.css and removed redundant styles from projects.css and scenarios.css.
- Ensured responsive design adjustments for form actions in smaller viewports.

templates/scenarios/profitability.html

@@ -20,16 +20,16 @@
     </div>
     <div class="header-actions">
       {% if scenario_url %}
-        <a class="btn" href="{{ scenario_url }}">Scenario Overview</a>
+        <a class="btn btn--secondary" href="{{ scenario_url }}">Scenario Overview</a>
       {% elif project_url %}
-        <a class="btn" href="{{ project_url }}">Project Overview</a>
+        <a class="btn btn--secondary" href="{{ project_url }}">Project Overview</a>
       {% elif cancel_url %}
-        <a class="btn" href="{{ cancel_url }}">Back</a>
+        <a class="btn btn--secondary" href="{{ cancel_url }}">Back</a>
       {% endif %}
       {% if scenario_portfolio_url %}
-        <a class="btn" href="{{ scenario_portfolio_url }}">Scenario Portfolio</a>
+        <a class="btn btn--secondary" href="{{ scenario_portfolio_url }}">Scenario Portfolio</a>
       {% endif %}
-      <button class="btn primary" type="submit" form="profitability-form">Run Calculation</button>
+      <button class="btn btn--primary" type="submit" form="profitability-form">Run Calculation</button>
     </div>
   </header>