diff --git a/src/js/settings.js b/src/js/settings.js
index 5bfdefc..8827ec8 100644
--- a/src/js/settings.js
+++ b/src/js/settings.js
@@ -80,6 +80,8 @@ function openThemeModal() {
   document.addEventListener('keydown', _themeTrap);
   const first = _focusable(modal)[0];
   if (first) first.focus();
+  syncCustomPickers();
+  document.getElementById('themeBuilderPanel').classList.toggle('hidden', settings.theme !== 'custom');
 }
 function closeThemeModal() {
   const overlay = document.getElementById('themeOverlay');
@@ -462,7 +464,11 @@ function applySettings() {
   const langEl = document.getElementById('settingLanguage');
   if (langEl) langEl.value = settings.language || 'auto';
 
-  applyTheme(settings.theme || 'nebula', !!settings.bgUrl);
+  if (settings.theme === 'custom') {
+    applyCustomTheme(settings.customTheme);
+  } else {
+    applyTheme(settings.theme || 'nebula', !!settings.bgUrl);
+  }
 
   if (settings.bgUrl && isValidBgUrl(settings.bgUrl)) {
     document.getElementById('bgLayer').style.backgroundImage = `url('${settings.bgUrl}')`;
@@ -489,10 +495,25 @@ function bindSettingsEvents() {
   const themeCards = document.querySelectorAll('.theme-card');
   function selectThemeCard(card) {
     const name = card.dataset.value;
-    if (!name || name === settings.theme) return Promise.resolve();
+    if (!name) return Promise.resolve();
+
+    // Custom: VOR dem name===settings.theme-Guard, damit ein Re-Klick das Panel wieder oeffnet.
+    if (name === 'custom') {
+      settings.theme = 'custom';
+      if (!settings.customTheme) settings.customTheme = { ...CUSTOM_DEFAULTS };
+      themeCards.forEach(c => c.setAttribute('aria-pressed', c === card ? 'true' : 'false'));
+      applyCustomTheme(settings.customTheme); // setzt data-theme + Inline-Vars; bgUrl UNANGETASTET (Koexistenz)
+      syncCustomPickers();
+      document.getElementById('themeBuilderPanel').classList.remove('hidden');
+      return saveSettings();
+    }
+
+    if (name === settings.theme) return Promise.resolve();
     settings.theme  = name;
     settings.bgUrl  = '';
     document.getElementById('bgUrlInput').value = '';
+    clearCustomTheme();                       // Inline-Vars weg beim Rueckwechsel auf ein Preset
+    document.getElementById('themeBuilderPanel').classList.add('hidden');
     // aria-pressed synchron halten — applyTheme/switchTheme pflegt nur die .active-Klasse, nicht ARIA
     themeCards.forEach(c => c.setAttribute('aria-pressed', c === card ? 'true' : 'false'));
     switchTheme(name); // WICHTIG: switchTheme aus Phase 4 (View-Transition-Wrapper), NICHT applyTheme direkt — sonst geht der Theme-Fade verloren
@@ -508,6 +529,31 @@ function bindSettingsEvents() {
     });
   });
 
+  // Theme-Builder Picker
+  const TB_PICKERS = [['tbAccent', 'accent'], ['tbBg', 'bgPrimary'], ['tbBoard', 'bgBoard'],
+                      ['tbText', 'textPrimary'], ['tbTextSec', 'textSecondary'], ['tbTextMuted', 'textMuted']];
+  TB_PICKERS.forEach(([id, key]) => {
+    const el = document.getElementById(id);
+    if (!el) return;
+    el.addEventListener('input', () => {                 // live waehrend des Ziehens
+      if (!settings.customTheme) settings.customTheme = { ...CUSTOM_DEFAULTS };
+      settings.customTheme[key] = el.value;
+      settings.theme = 'custom';
+      applyCustomTheme(settings.customTheme);
+    });
+    el.addEventListener('change', () => saveSettings()); // persistiert beim Loslassen/Schliessen
+  });
+
+  const tbReset = document.getElementById('tbReset');
+  if (tbReset) {
+    tbReset.addEventListener('click', async () => {
+      settings.customTheme = { ...CUSTOM_DEFAULTS };
+      applyCustomTheme(settings.customTheme);
+      syncCustomPickers();
+      await saveSettings();
+    });
+  }
+
   // Accordion initialisieren
   initAccordion();
 
@@ -639,6 +685,7 @@ function bindSettingsEvents() {
                  hideExtra: false, visibleCount: 10, bgUrl: '', theme: 'nebula',
                  showSearch: true, searchEngine: 'google', toolbarPos: 'right',
                  imageRefEnabled: false, language: 'auto', customTheme: null };
+    clearCustomTheme();
     await saveBoards();
     await saveTrash();
     await saveSettings();