feat: add increase/decrease text size buttons

src/lib/components/ToolbarExpanded.svelte

@@ -20,6 +20,7 @@
   import { DEFAULT_HF_DISTANCES, clampHfDistance, type HfDistances } from '../storage/headerFooter';
   import { blockFontSize, coversWholeBlock, DEFAULT_FONT_SIZE, FONT_SIZES, type SizedBlock } from '../utils/fontSize';
   import { listContext } from '../editor/extensions/indent';
+  import { stepFontSize } from '../editor/extensions/shortcuts';
   import { findColumns, DEFAULT_COLUMN_GAP_CM } from '../editor/extensions/columns';
   import { t } from '../i18n/i18n.svelte';
   import { shortcutHint, type ShortcutId } from '../editor/shortcuts';
@@ -1089,6 +1090,27 @@
       {/if}
     </div>
 
+    <div class="toolbar-group">
+      <button
+        onclick={() => editor && stepFontSize(editor, 1)}
+        title={`${t().toolbarExpanded.growFont} (${shortcutHint('fontGrow')})`}
+      >
+        <svg width="16" height="16" viewBox="0 0 16 16" fill="none" aria-hidden="true">
+          <text x="5" y="14" text-anchor="middle" font-size="15" font-family="sans-serif" fill="currentColor">A</text>
+          <path d="M12.5 12V5m0 0L10.5 7m2-2l2 2" stroke="currentColor" stroke-width="1.3" stroke-linecap="round" stroke-linejoin="round"/>
+        </svg>
+      </button>
+      <button
+        onclick={() => editor && stepFontSize(editor, -1)}
+        title={`${t().toolbarExpanded.shrinkFont} (${shortcutHint('fontShrink')})`}
+      >
+        <svg width="16" height="16" viewBox="0 0 16 16" fill="none" aria-hidden="true">
+          <text x="5" y="14" text-anchor="middle" font-size="11" font-family="sans-serif" fill="currentColor">A</text>
+          <path d="M12.5 5v7m0 0l-2-2m2 2l2-2" stroke="currentColor" stroke-width="1.3" stroke-linecap="round" stroke-linejoin="round"/>
+        </svg>
+      </button>
+    </div>
+
     <div class="toolbar-separator"></div>
 
     <div class="toolbar-group">

src/lib/editor/extensions/shortcuts.ts

@@ -33,7 +33,8 @@ function currentSizePt(editor: Editor): number {
 }
 
 // Word's Ctrl+Shift+> / <: jump to the next size on the toolbar's ladder.
-function stepFontSize(editor: Editor, dir: 1 | -1): boolean {
+// Also the grow/shrink toolbar buttons.
+export function stepFontSize(editor: Editor, dir: 1 | -1): boolean {
   const cur = currentSizePt(editor);
   const ladder = dir > 0 ? FONT_SIZES : [...FONT_SIZES].reverse();
   const next = ladder.find((s) => (dir > 0 ? s > cur : s < cur));

src/lib/i18n/locales/de.ts

@@ -112,6 +112,8 @@ const de: Messages = {
     loadAllFonts: 'Alle installierten Schriften laden',
     fontSize: 'Schriftgröße',
     fontSizeList: 'Schriftgrößenliste',
+    growFont: 'Schrift vergrößern',
+    shrinkFont: 'Schrift verkleinern',
     fontColor: 'Schriftfarbe',
     chooseFontColor: 'Schriftfarbe wählen',
     highlightColor: 'Hervorhebungsfarbe',

src/lib/i18n/locales/en.ts

@@ -116,6 +116,8 @@ const en = {
     loadAllFonts: 'Load all installed fonts',
     fontSize: 'Font size',
     fontSizeList: 'Font size list',
+    growFont: 'Increase font size',
+    shrinkFont: 'Decrease font size',
     fontColor: 'Font color',
     chooseFontColor: 'Choose font color',
     highlightColor: 'Highlight color',