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/login.html

@@ -26,7 +26,7 @@
       <label for="password">Password:</label>
       <input type="password" id="password" name="password" required />
     </div>
-    <button type="submit" class="btn primary">Login</button>
+  <button type="submit" class="btn btn--primary">Login</button>
   </form>
   <p>Don't have an account? <a href="/register">Register here</a></p>
   <p><a href="/forgot-password">Forgot password?</a></p>