Add paystro visual components

src/utils/theme.ts

@@ -0,0 +1,21 @@
+export function switchTheme(themeClass: string): void {
+  const bodyElement = document.body
+  const classesToRemove = ['light', 'dark', 'autonomic']
+
+  bodyElement.classList.remove(...classesToRemove)
+  bodyElement.classList.add(themeClass)
+}
+
+export function handleThemeChange(event: Event): void {
+  const selectElement = event.target as HTMLSelectElement
+  const selectedTheme = selectElement.value
+
+  switchTheme(selectedTheme)
+}
+
+export function initializeThemeSelector(): void {
+  const themeSelector = document.getElementById('theme-selector')
+  if (themeSelector) {
+    themeSelector.addEventListener('change', handleThemeChange)
+  }
+}