Improve action button styling and structure across pages

Introduced a new design and layout for action buttons on AlertsPage, DashboardPage, and TargetsPage with consistent styles and added SVG icons. Updated styles.css to support these changes with reusable button classes for better maintainability and UI consistency.

frontend/src/pages/DashboardPage.jsx

@@ -110,7 +110,14 @@ export function DashboardPage() {
                   <p><strong>DB:</strong> {t.dbname}</p>
                 </div>
                 <div className="target-actions">
-                  <Link className="details-btn" to={`/targets/${t.id}`}>Details <span aria-hidden="true">{"->"}</span></Link>
+                  <Link className="table-action-btn details" to={`/targets/${t.id}`}>
+                    <span aria-hidden="true">
+                      <svg viewBox="0 0 24 24" width="13" height="13">
+                        <path d="M2 12s3.5-6 10-6 10 6 10 6-3.5 6-10 6-10-6-10-6zm10 3a3 3 0 1 0 0-6 3 3 0 0 0 0 6z" fill="currentColor" />
+                      </svg>
+                    </span>
+                    Details
+                  </Link>
                 </div>
               </article>
             );