Nexus upgrade design and refresh

public/assets/js/app.js

@@ -28,6 +28,55 @@
   });
 })();
 
+document.documentElement.classList.add('js');
+
+function readThemePreference(key, fallback) {
+  try {
+    return localStorage.getItem(key) || fallback;
+  } catch (error) {
+    return fallback;
+  }
+}
+
+const themeMode = readThemePreference('nexus.theme', document.documentElement.dataset.theme || 'day');
+const themeAccent = readThemePreference('nexus.accent', document.documentElement.dataset.accent || 'logo');
+
+function applyTheme(mode, accent) {
+  const normalizedMode = ['day', 'night'].includes(mode) ? mode : 'day';
+  const normalizedAccent = ['logo', 'pink', 'cyan', 'orange', 'green'].includes(accent) ? accent : 'logo';
+  document.documentElement.dataset.theme = normalizedMode;
+  document.documentElement.dataset.accent = normalizedAccent;
+  try {
+    localStorage.setItem('nexus.theme', normalizedMode);
+    localStorage.setItem('nexus.accent', normalizedAccent);
+  } catch (error) {
+    // Ignore blocked storage; the current page still receives the theme.
+  }
+}
+
+applyTheme(themeMode, themeAccent);
+
+const themeModeSelect = document.querySelector('[data-theme-mode]');
+const themeAccentSelect = document.querySelector('[data-theme-accent]');
+
+if (themeModeSelect) {
+  themeModeSelect.value = document.documentElement.dataset.theme;
+  themeModeSelect.addEventListener('change', () => {
+    applyTheme(themeModeSelect.value, document.documentElement.dataset.accent);
+  });
+}
+
+if (themeAccentSelect) {
+  themeAccentSelect.value = document.documentElement.dataset.accent;
+  themeAccentSelect.addEventListener('change', () => {
+    applyTheme(document.documentElement.dataset.theme, themeAccentSelect.value);
+  });
+}
+
+for (const element of document.querySelectorAll('[data-reveal]')) {
+  element.classList.add('reveal');
+}
+
 (() => {
   const openBtn = document.querySelector('[data-debug-open]');
   const modal = document.getElementById('debug-modal');