diff --git a/public/assets/css/stylesheet.print.css b/public/assets/css/stylesheet.print.css
index 12776e7..fd8619e 100644
--- a/public/assets/css/stylesheet.print.css
+++ b/public/assets/css/stylesheet.print.css
@@ -1,8 +1,4 @@
-@page {
-  size: A5;
-  margin: 20mm 15mm 26mm 15mm;
-  background: rgba(255, 255, 255, 1);
-}
+
 
 @page {
   @bottom-center {
@@ -10,9 +6,6 @@
   }
 }
 
-body {
-  font-family: "DM Sans", sans-serif;
-}
 
 
 
@@ -21,10 +14,7 @@ figure, img{
   margin: 0;
 }
 
-p{
-  font-size: 14px;
-  line-height: 18px;
-}
+
 
 
 /* ───────────────────────────────────────────
diff --git a/src/components/editor/PageSettings.vue b/src/components/editor/PageSettings.vue
index beed919..c945660 100644
--- a/src/components/editor/PageSettings.vue
+++ b/src/components/editor/PageSettings.vue
@@ -197,6 +197,7 @@
 <script setup>
 import { ref, computed, watch, onMounted, inject, nextTick } from 'vue';
 import bookIcon from '/assets/svg/book.svg?raw';
+import { PAGE_DEFAULTS } from '../../utils/defaults';
 import { useStylesheetStore } from '../../stores/stylesheet';
 import { useDebounce } from '../../composables/useDebounce';
 import { useCssSync } from '../../composables/useCssSync';
@@ -212,25 +213,18 @@ const activeTab = inject('activeTab', ref('document'));
 
 let isUpdatingFromStore = false;
 
-const pageFormat = ref('A4');
+const pageFormat = ref(PAGE_DEFAULTS.format);
+const pageFormats = PAGE_DEFAULTS.formats;
 
-const pageFormats = {
-  A4: { width: 210, height: 297 },
-  A5: { width: 148, height: 210 },
-  // A3: { width: 297, height: 420 },
-  // letter: { width: 216, height: 279 },
-  // legal: { width: 216, height: 356 },
-};
-
-const customWidth = ref(210);
-const customHeight = ref(297);
+const customWidth = ref(PAGE_DEFAULTS.formats[PAGE_DEFAULTS.format].width);
+const customHeight = ref(PAGE_DEFAULTS.formats[PAGE_DEFAULTS.format].height);
 const isCustomFormat = computed(() => pageFormat.value === 'custom');
 
 const margins = ref({
-  top: { value: 20, unit: 'mm' },
-  bottom: { value: 20, unit: 'mm' },
-  left: { value: 20, unit: 'mm' },
-  right: { value: 20, unit: 'mm' },
+  top: { ...PAGE_DEFAULTS.margins.top },
+  bottom: { ...PAGE_DEFAULTS.margins.bottom },
+  left: { ...PAGE_DEFAULTS.margins.left },
+  right: { ...PAGE_DEFAULTS.margins.right },
 });
 
 const updateMarginUnit = (side, newUnit) => {
diff --git a/src/components/editor/TextSettings.vue b/src/components/editor/TextSettings.vue
index ef02dc1..b027ce5 100644
--- a/src/components/editor/TextSettings.vue
+++ b/src/components/editor/TextSettings.vue
@@ -81,6 +81,7 @@
 <script setup>
 import { ref, watch, onMounted, nextTick } from 'vue';
 import textIcon from '/assets/svg/text.svg?raw';
+import { TEXT_DEFAULTS } from '../../utils/defaults';
 import { initColoris } from '../../composables/useColoris';
 import InputWithUnit from '../ui/InputWithUnit.vue';
 import { useCssUpdater } from '../../composables/useCssUpdater';
@@ -95,11 +96,11 @@ const { debouncedUpdate } = useDebounce(500);
 const textDefaults = useTextDefaults();
 const { fonts: projectFonts, loadFont, loadAllFontPreviews } = useProjectFonts();
 
-// State — initial values match stylesheet.print.css (overwritten by syncFromStore)
-const font = ref('sans-serif');
-const fontSize = ref({ value: 14, unit: 'px' });
-const lineHeight = ref({ value: 18, unit: 'px' });
-const color = ref('rgb(0, 0, 0)');
+// State — initial values from defaults.js (overwritten by syncFromStore)
+const font = ref(TEXT_DEFAULTS.fontFamily);
+const fontSize = ref({ ...TEXT_DEFAULTS.fontSize });
+const lineHeight = ref({ ...TEXT_DEFAULTS.lineHeight });
+const color = ref(TEXT_DEFAULTS.color);
 const colorInput = ref(null);
 
 // Start true to block immediate watchers from overwriting textDefaults during setup
diff --git a/src/composables/useElementSettings.js b/src/composables/useElementSettings.js
index c98b775..cd8a4ff 100644
--- a/src/composables/useElementSettings.js
+++ b/src/composables/useElementSettings.js
@@ -1,4 +1,5 @@
 import { ref, reactive, computed, watch, nextTick } from 'vue';
+import { ELEMENT_DEFAULTS } from '../utils/defaults';
 import { useStylesheetStore } from '../stores/stylesheet';
 import { useDebounce } from './useDebounce';
 import { useTextDefaults } from './useTextDefaults';
@@ -15,26 +16,26 @@ export function useElementSettings({ margin, padding, basePopup }) {
   // --- Selector state ---
   const selector = ref('');
 
-  // --- Style refs ---
-  const fontFamily = ref('sans-serif');
-  const italic = ref(false);
-  const bold = ref(false);
-  const textAlign = ref('left');
-  const color = ref('rgb(0, 0, 0)');
-  const background = ref('transparent');
-  const fontSize = reactive({ value: 23, unit: 'px' });
+  // --- Style refs (initial values from defaults.js) ---
+  const fontFamily = ref(ELEMENT_DEFAULTS.fontFamily);
+  const italic = ref(ELEMENT_DEFAULTS.italic);
+  const bold = ref(ELEMENT_DEFAULTS.bold);
+  const textAlign = ref(ELEMENT_DEFAULTS.textAlign);
+  const color = ref(ELEMENT_DEFAULTS.color);
+  const background = ref(ELEMENT_DEFAULTS.background);
+  const fontSize = reactive({ ...ELEMENT_DEFAULTS.fontSize });
   const fontSizeModel = computed({
     get: () => ({ value: fontSize.value, unit: fontSize.unit }),
     set: (v) => { fontSize.value = v.value; fontSize.unit = v.unit; },
   });
-  const lineHeight = reactive({ value: 28, unit: 'px' });
+  const lineHeight = reactive({ ...ELEMENT_DEFAULTS.lineHeight });
   const lineHeightModel = computed({
     get: () => ({ value: lineHeight.value, unit: lineHeight.unit }),
     set: (v) => { lineHeight.value = v.value; lineHeight.unit = v.unit; },
   });
-  const borderWidth = reactive({ value: 1, unit: 'px' });
-  const borderStyle = ref('solid');
-  const borderColor = ref('#000000');
+  const borderWidth = reactive({ ...ELEMENT_DEFAULTS.borderWidth });
+  const borderStyle = ref(ELEMENT_DEFAULTS.borderStyle);
+  const borderColor = ref(ELEMENT_DEFAULTS.borderColor);
 
   // --- Toggle state ---
   const settingEnabled = reactive({
diff --git a/src/composables/useTextDefaults.js b/src/composables/useTextDefaults.js
index f858c0e..3acee9c 100644
--- a/src/composables/useTextDefaults.js
+++ b/src/composables/useTextDefaults.js
@@ -1,12 +1,12 @@
 import { reactive } from 'vue';
+import { TEXT_DEFAULTS } from '../utils/defaults';
 
 // Singleton reactive — TextSettings writes here, ElementPopup reads when disabled
-// Initial values match stylesheet.print.css (overwritten by syncFromStore on first mount)
+// Initial values from defaults.js (overwritten by syncFromStore on first mount)
 const defaults = reactive({
-  fontSize: { value: 14, unit: 'px' },
-  lineHeight: { value: 18, unit: 'px' },
-  fontFamily: 'sans-serif',
-  color: 'rgb(0, 0, 0)',
+  ...TEXT_DEFAULTS,
+  fontSize: { ...TEXT_DEFAULTS.fontSize },
+  lineHeight: { ...TEXT_DEFAULTS.lineHeight },
   _initialized: false,
 });
 
diff --git a/src/stores/stylesheet.js b/src/stores/stylesheet.js
index 0803400..ee31953 100644
--- a/src/stores/stylesheet.js
+++ b/src/stores/stylesheet.js
@@ -5,6 +5,7 @@ import * as cssComments from '../utils/css-comments';
 import prettier from 'prettier/standalone';
 import parserPostcss from 'prettier/plugins/postcss';
 import { getCsrfToken } from '../utils/kirby-auth';
+import { PAGE_DEFAULTS, TEXT_DEFAULTS } from '../utils/defaults';
 
 export const useStylesheetStore = defineStore('stylesheet', () => {
   // Base state
@@ -167,6 +168,34 @@ export const useStylesheetStore = defineStore('stylesheet', () => {
     return baseCss.value;
   };
 
+  // Inject default CSS values if not already present in base or custom CSS
+  const applyDefaultsCss = () => {
+    const has = (selector, property) => {
+      return cssParsingUtils.extractCssValue(baseCss.value, selector, property)
+        || cssParsingUtils.extractCssValue(customCss.value, selector, property);
+    };
+
+    const set = (selector, property, value, unit = '') => {
+      if (!has(selector, property)) {
+        customCss.value = cssParsingUtils.updateCssValue({
+          css: customCss.value, selector, property, value, unit,
+        });
+      }
+    };
+
+    // Page defaults
+    set('@page', 'size', PAGE_DEFAULTS.format);
+    const m = PAGE_DEFAULTS.margins;
+    set('@page', 'margin', `${m.top.value}${m.top.unit} ${m.right.value}${m.right.unit} ${m.bottom.value}${m.bottom.unit} ${m.left.value}${m.left.unit}`);
+
+    // Text defaults
+    const fontVal = TEXT_DEFAULTS.fontFamily === 'sans-serif' ? 'sans-serif' : `"${TEXT_DEFAULTS.fontFamily}"`;
+    set('body', 'font-family', fontVal);
+    set('body', 'color', TEXT_DEFAULTS.color);
+    set('p', 'font-size', TEXT_DEFAULTS.fontSize.value, TEXT_DEFAULTS.fontSize.unit);
+    set('p', 'line-height', TEXT_DEFAULTS.lineHeight.value, TEXT_DEFAULTS.lineHeight.unit);
+  };
+
   // Initialize from narrative data (base + custom CSS)
   const initializeFromNarrative = async (narrativeData) => {
     // Set initializing flag to prevent marking as dirty during init
@@ -182,6 +211,9 @@ export const useStylesheetStore = defineStore('stylesheet', () => {
       // Get custom CSS if exists
       customCss.value = narrativeData.customCss || '';
 
+      // Inject defaults if missing from CSS
+      applyDefaultsCss();
+
       // Set last saved info
       if (narrativeData.modified) {
         lastSaved.value = narrativeData.modified;
diff --git a/src/utils/defaults.js b/src/utils/defaults.js
new file mode 100644
index 0000000..8b93fa5
--- /dev/null
+++ b/src/utils/defaults.js
@@ -0,0 +1,48 @@
+/**
+ * Default values for the application.
+ * Single source of truth — imported by components, composables, and stores.
+ * These are static launch values, NOT user-configured defaults.
+ */
+
+export const PAGE_DEFAULTS = Object.freeze({
+  format: 'A5',
+  formats: Object.freeze({
+    A4: Object.freeze({ width: 210, height: 297 }),
+    A5: Object.freeze({ width: 148, height: 210 }),
+  }),
+  margins: Object.freeze({
+    top: Object.freeze({ value: 16, unit: 'mm' }),
+    bottom: Object.freeze({ value: 16, unit: 'mm' }),
+    left: Object.freeze({ value: 16, unit: 'mm' }),
+    right: Object.freeze({ value: 16, unit: 'mm' }),
+  }),
+  background: '',
+});
+
+export const TEXT_DEFAULTS = Object.freeze({
+  fontFamily: 'sans-serif',
+  fontSize: Object.freeze({ value: 14, unit: 'px' }),
+  lineHeight: Object.freeze({ value: 18, unit: 'px' }),
+  color: 'rgb(0, 0, 0)',
+});
+
+export const ELEMENT_DEFAULTS = Object.freeze({
+  fontFamily: 'sans-serif',
+  italic: false,
+  bold: false,
+  textAlign: 'left',
+  color: 'rgb(0, 0, 0)',
+  background: 'transparent',
+  fontSize: Object.freeze({ value: 14, unit: 'px' }),
+  lineHeight: Object.freeze({ value: 18, unit: 'px' }),
+  borderWidth: Object.freeze({ value: 1, unit: 'px' }),
+  borderStyle: 'solid',
+  borderColor: '#000000',
+});
+
+export const INLINE_DEFAULTS = Object.freeze({
+  em: Object.freeze({ fontStyle: 'italic' }),
+  i: Object.freeze({ fontStyle: 'italic' }),
+  strong: Object.freeze({ fontWeight: 'bold' }),
+  b: Object.freeze({ fontWeight: 'bold' }),
+});