diff --git a/desktop-app/resources/index.html b/desktop-app/resources/index.html
index 9bfbf0c..fccf41e 100644
--- a/desktop-app/resources/index.html
+++ b/desktop-app/resources/index.html
@@ -269,6 +269,11 @@ <h5>Menu</h5>
             <button type="button" class="markdown-tool-btn text-tool" data-md-action="uppercase" title="Uppercase" aria-label="Uppercase">A</button>
             <button type="button" class="markdown-tool-btn text-tool" data-md-action="lowercase" title="Lowercase" aria-label="Lowercase">a</button>
           </div>
+          <div class="markdown-toolbar-group">
+            <button type="button" class="markdown-tool-btn" data-md-action="align-left" title="Align left" aria-label="Align left"><i class="bi bi-text-left"></i></button>
+            <button type="button" class="markdown-tool-btn" data-md-action="align-center" title="Align center" aria-label="Align center"><i class="bi bi-text-center"></i></button>
+            <button type="button" class="markdown-tool-btn" data-md-action="align-right" title="Align right" aria-label="Align right"><i class="bi bi-text-right"></i></button>
+          </div>
           <div class="markdown-toolbar-group heading-group">
             <button type="button" class="markdown-tool-btn text-tool" data-md-action="heading" data-md-level="1" title="Heading 1" aria-label="Heading 1">H1</button>
             <button type="button" class="markdown-tool-btn text-tool" data-md-action="heading" data-md-level="2" title="Heading 2" aria-label="Heading 2">H2</button>
diff --git a/desktop-app/resources/js/script.js b/desktop-app/resources/js/script.js
index 1644be0..aeb5974 100644
--- a/desktop-app/resources/js/script.js
+++ b/desktop-app/resources/js/script.js
@@ -290,7 +290,7 @@ document.addEventListener("DOMContentLoaded", function () {
       path: "M256 512A256 256 0 1 0 256 0a256 256 0 1 0 0 512zM175 175c9.4-9.4 24.6-9.4 33.9 0l47 47 47-47c9.4-9.4 24.6-9.4 33.9 0s9.4 24.6 0 33.9l-47 47 47 47c9.4 9.4 9.4 24.6 0 33.9s-24.6 9.4-33.9 0l-47-47-47 47c-9.4 9.4-24.6 9.4-33.9 0s-9.4-24.6 0-33.9l47-47-47-47c-9.4-9.4-9.4-24.6 0-33.9z",
     },
   };
-  const GITHUB_ALERT_MARKER_REGEX = /^\[!(NOTE|TIP|IMPORTANT|WARNING|CAUTION)\](?:\s+|$)/i;
+  const GITHUB_ALERT_MARKER_REGEX = /^\[!(NOTE|TIP|IMPORTANT|WARNING|CAUTION)\](?:(?:\s|&nbsp;|<br\s*\/?>)+|$)/i;
 
   function enhanceGitHubAlerts(container) {
     if (!container) return;
@@ -306,8 +306,8 @@ document.addEventListener("DOMContentLoaded", function () {
       }
       if (!firstParagraph) return;
 
-      const firstParagraphHtml = firstParagraph.innerHTML.trim();
-      const markerMatch = firstParagraphHtml.match(GITHUB_ALERT_MARKER_REGEX);
+    const firstParagraphHtml = firstParagraph.innerHTML.trim();
+    const markerMatch = firstParagraphHtml.match(GITHUB_ALERT_MARKER_REGEX);
       if (!markerMatch) return;
 
       const alertType = markerMatch[1].toLowerCase();
@@ -336,9 +336,9 @@ document.addEventListener("DOMContentLoaded", function () {
 
       blockquote.insertBefore(title, blockquote.firstChild);
 
-      const remainingHtml = firstParagraphHtml
-        .replace(GITHUB_ALERT_MARKER_REGEX, "")
-        .trim();
+    const remainingHtml = firstParagraphHtml
+      .replace(GITHUB_ALERT_MARKER_REGEX, "")
+      .trim();
       if (remainingHtml) {
         firstParagraph.innerHTML = remainingHtml;
       } else {
@@ -1076,7 +1076,7 @@ This is a fully client-side application. Your content never leaves your browser
       const html = tableHtml + marked.parse(referenceData.cleanedMarkdown);
       const sanitizedHtml = DOMPurify.sanitize(html, {
         ADD_TAGS: ['mjx-container'],
-        ADD_ATTR: ['id', 'class', 'style'],
+        ADD_ATTR: ['id', 'class', 'style', 'align'],
         ALLOWED_URI_REGEXP: /^(?:(?:https?|mailto|tel|blob):|[^a-z]|[a-z+.\-]+(?:[^a-z+.\-:]|$))/i
       });
       markdownPreview.innerHTML = sanitizedHtml;
@@ -2168,6 +2168,30 @@ This is a fully client-side application. Your content never leaves your browser
     });
   }
 
+  function insertAlignmentBlock(align) {
+    const allowedAlignments = new Set(['left', 'center', 'right']);
+    const isAllowed = allowedAlignments.has(align);
+    if (!isAllowed) {
+      console.warn('Unsupported alignment:', align);
+      return;
+    }
+    const safeAlign = align;
+    const value = markdownEditor.value;
+    const start = markdownEditor.selectionStart;
+    const end = markdownEditor.selectionEnd;
+    const selected = value.slice(start, end);
+    const hasSelection = start !== end;
+    const blockStart = `<div align="${safeAlign}">\n`;
+    const blockEnd = `\n</div>`;
+    const block = `${blockStart}${hasSelection ? selected : ''}${blockEnd}`;
+    const needsLeadingBreak = start > 0 && value[start - 1] !== '\n';
+    const needsTrailingBreak = end < value.length && value[end] !== '\n';
+    const replacement = (needsLeadingBreak ? '\n' : '') + block + (needsTrailingBreak ? '\n' : '');
+    const contentStart = start + (needsLeadingBreak ? 1 : 0) + blockStart.length;
+    const contentEnd = contentStart + (hasSelection ? selected.length : 0);
+    replaceEditorRange(start, end, replacement, contentStart, hasSelection ? contentEnd : contentStart);
+  }
+
   function insertMarkdownBlock(block, startOverride, endOverride) {
     const value = markdownEditor.value;
     const start = typeof startOverride === 'number' ? startOverride : markdownEditor.selectionStart;
@@ -3348,6 +3372,9 @@ This is a fully client-side application. Your content never leaves your browser
     else if (action === 'strike') wrapEditorSelection('~~', '~~', 'struck text');
     else if (action === 'italic') wrapEditorSelection('*', '*', 'italic text');
     else if (action === 'quote') transformEditorLines(function(line) { return line ? '> ' + line.replace(/^>\s?/, '') : '>'; });
+    else if (action === 'align-left') insertAlignmentBlock('left');
+    else if (action === 'align-center') insertAlignmentBlock('center');
+    else if (action === 'align-right') insertAlignmentBlock('right');
     else if (action === 'title-case') transformSelectionOrCurrentLine(toTitleCase);
     else if (action === 'uppercase') transformSelectionOrCurrentLine(function(text) { return text.toUpperCase(); });
     else if (action === 'lowercase') transformSelectionOrCurrentLine(function(text) { return text.toLowerCase(); });
@@ -3720,7 +3747,7 @@ This is a fully client-side application. Your content never leaves your browser
       const html = marked.parse(markdown);
       const sanitizedHtml = DOMPurify.sanitize(html, {
         ADD_TAGS: ['mjx-container'], 
-        ADD_ATTR: ['id', 'class', 'style']
+        ADD_ATTR: ['id', 'class', 'style', 'align']
       });
       const tempContainer = document.createElement("div");
       tempContainer.innerHTML = sanitizedHtml;
@@ -4338,7 +4365,7 @@ This is a fully client-side application. Your content never leaves your browser
       const html = marked.parse(markdown);
       const sanitizedHtml = DOMPurify.sanitize(html, {
         ADD_TAGS: ['mjx-container', 'svg', 'path', 'g', 'marker', 'defs', 'pattern', 'clipPath'],
-        ADD_ATTR: ['id', 'class', 'style', 'viewBox', 'd', 'fill', 'stroke', 'transform', 'marker-end', 'marker-start']
+        ADD_ATTR: ['id', 'class', 'style', 'align', 'viewBox', 'd', 'fill', 'stroke', 'transform', 'marker-end', 'marker-start']
       });
 
       const tempElement = document.createElement("div");
diff --git a/index.html b/index.html
index 0f0fddf..939caab 100644
--- a/index.html
+++ b/index.html
@@ -135,6 +135,9 @@ <h1 class="h4 mb-0 me-2">Markdown Viewer</h1>
                         <i class="bi bi-share"></i> <span class="btn-text">Share</span>
                     </button>
                     
+                    <button id="direction-toggle" class="tool-button" title="Toggle RTL/LTR" aria-label="Toggle text direction">
+                        <i class="bi bi-text-right"></i>
+                    </button>
                     <button id="theme-toggle" class="tool-button" title="Toggle Dark Mode">
                         <i class="bi bi-moon"></i>
                     </button>
@@ -231,6 +234,9 @@ <h5>Menu</h5>
                                 <i class="bi bi-share me-2"></i> Share
                             </button>
                             
+                            <button id="mobile-direction-toggle" class="mobile-menu-item" title="Toggle RTL/LTR">
+                                <i class="bi bi-text-right me-2"></i> Switch to RTL
+                            </button>
                             <button id="mobile-theme-toggle" class="mobile-menu-item" title="Toggle Dark Mode">
                                 <i class="bi bi-moon me-2"></i> Dark Mode
                             </button>
@@ -266,6 +272,11 @@ <h5>Menu</h5>
             <button type="button" class="markdown-tool-btn text-tool" data-md-action="uppercase" title="Uppercase" aria-label="Uppercase">A</button>
             <button type="button" class="markdown-tool-btn text-tool" data-md-action="lowercase" title="Lowercase" aria-label="Lowercase">a</button>
           </div>
+          <div class="markdown-toolbar-group">
+            <button type="button" class="markdown-tool-btn" data-md-action="align-left" title="Align left" aria-label="Align left"><i class="bi bi-text-left"></i></button>
+            <button type="button" class="markdown-tool-btn" data-md-action="align-center" title="Align center" aria-label="Align center"><i class="bi bi-text-center"></i></button>
+            <button type="button" class="markdown-tool-btn" data-md-action="align-right" title="Align right" aria-label="Align right"><i class="bi bi-text-right"></i></button>
+          </div>
           <div class="markdown-toolbar-group heading-group">
             <button type="button" class="markdown-tool-btn text-tool" data-md-action="heading" data-md-level="1" title="Heading 1" aria-label="Heading 1">H1</button>
             <button type="button" class="markdown-tool-btn text-tool" data-md-action="heading" data-md-level="2" title="Heading 2" aria-label="Heading 2">H2</button>
diff --git a/script.js b/script.js
index 1644be0..2d8ca04 100644
--- a/script.js
+++ b/script.js
@@ -21,6 +21,7 @@ document.addEventListener("DOMContentLoaded", function () {
   const markdownPreview = document.getElementById("markdown-preview");
   const markdownFormatToolbar = document.getElementById("markdown-format-toolbar");
   const themeToggle = document.getElementById("theme-toggle");
+  const directionToggle = document.getElementById("direction-toggle");
   const importFromFileButton = document.getElementById("import-from-file");
   const importFromGithubButton = document.getElementById("import-from-github");
   const fileInput = document.getElementById("file-input");
@@ -66,6 +67,7 @@ document.addEventListener("DOMContentLoaded", function () {
   const mobileExportPdf     = document.getElementById("mobile-export-pdf");
   const mobileCopyMarkdown  = document.getElementById("mobile-copy-markdown");
   const mobileThemeToggle   = document.getElementById("mobile-theme-toggle");
+  const mobileDirectionToggle = document.getElementById("mobile-direction-toggle");
   const shareButton         = document.getElementById("share-button");
   const mobileShareButton   = document.getElementById("mobile-share-button");
   const githubImportModal = document.getElementById("github-import-modal");
@@ -209,6 +211,30 @@ document.addEventListener("DOMContentLoaded", function () {
     ? '<i class="bi bi-sun"></i>'
     : '<i class="bi bi-moon"></i>';
 
+  function updateDirectionToggleUI(direction) {
+    const isRtl = direction === "rtl";
+    const toggleLabel = isRtl ? "Switch to LTR" : "Switch to RTL";
+    if (directionToggle) {
+      directionToggle.innerHTML = isRtl
+        ? '<i class="bi bi-text-left"></i>'
+        : '<i class="bi bi-text-right"></i>';
+      directionToggle.setAttribute("title", toggleLabel);
+      directionToggle.setAttribute("aria-label", toggleLabel);
+      directionToggle.setAttribute("aria-pressed", isRtl.toString());
+    }
+    if (mobileDirectionToggle) {
+      const icon = isRtl
+        ? '<i class="bi bi-text-left me-2"></i>'
+        : '<i class="bi bi-text-right me-2"></i>';
+      mobileDirectionToggle.innerHTML = `${icon} ${toggleLabel}`;
+    }
+  }
+
+  const savedDirection = loadGlobalState().direction;
+  const initialDirection = savedDirection === "rtl" ? "rtl" : "ltr";
+  document.documentElement.setAttribute("dir", initialDirection);
+  updateDirectionToggleUI(initialDirection);
+
   const initMermaid = () => {
     const currentTheme = document.documentElement.getAttribute("data-theme");
     const mermaidTheme = currentTheme === "dark" ? "dark" : "default";
@@ -290,7 +316,7 @@ document.addEventListener("DOMContentLoaded", function () {
       path: "M256 512A256 256 0 1 0 256 0a256 256 0 1 0 0 512zM175 175c9.4-9.4 24.6-9.4 33.9 0l47 47 47-47c9.4-9.4 24.6-9.4 33.9 0s9.4 24.6 0 33.9l-47 47 47 47c9.4 9.4 9.4 24.6 0 33.9s-24.6 9.4-33.9 0l-47-47-47 47c-9.4 9.4-24.6 9.4-33.9 0s-9.4-24.6 0-33.9l47-47-47-47c-9.4-9.4-9.4-24.6 0-33.9z",
     },
   };
-  const GITHUB_ALERT_MARKER_REGEX = /^\[!(NOTE|TIP|IMPORTANT|WARNING|CAUTION)\](?:\s+|$)/i;
+  const GITHUB_ALERT_MARKER_REGEX = /^\[!(NOTE|TIP|IMPORTANT|WARNING|CAUTION)\](?:(?:\s|&nbsp;|<br\s*\/?>)+|$)/i;
 
   function enhanceGitHubAlerts(container) {
     if (!container) return;
@@ -306,8 +332,8 @@ document.addEventListener("DOMContentLoaded", function () {
       }
       if (!firstParagraph) return;
 
-      const firstParagraphHtml = firstParagraph.innerHTML.trim();
-      const markerMatch = firstParagraphHtml.match(GITHUB_ALERT_MARKER_REGEX);
+    const firstParagraphHtml = firstParagraph.innerHTML.trim();
+    const markerMatch = firstParagraphHtml.match(GITHUB_ALERT_MARKER_REGEX);
       if (!markerMatch) return;
 
       const alertType = markerMatch[1].toLowerCase();
@@ -336,9 +362,9 @@ document.addEventListener("DOMContentLoaded", function () {
 
       blockquote.insertBefore(title, blockquote.firstChild);
 
-      const remainingHtml = firstParagraphHtml
-        .replace(GITHUB_ALERT_MARKER_REGEX, "")
-        .trim();
+    const remainingHtml = firstParagraphHtml
+      .replace(GITHUB_ALERT_MARKER_REGEX, "")
+      .trim();
       if (remainingHtml) {
         firstParagraph.innerHTML = remainingHtml;
       } else {
@@ -1076,7 +1102,7 @@ This is a fully client-side application. Your content never leaves your browser
       const html = tableHtml + marked.parse(referenceData.cleanedMarkdown);
       const sanitizedHtml = DOMPurify.sanitize(html, {
         ADD_TAGS: ['mjx-container'],
-        ADD_ATTR: ['id', 'class', 'style'],
+        ADD_ATTR: ['id', 'class', 'style', 'align'],
         ALLOWED_URI_REGEXP: /^(?:(?:https?|mailto|tel|blob):|[^a-z]|[a-z+.\-]+(?:[^a-z+.\-:]|$))/i
       });
       markdownPreview.innerHTML = sanitizedHtml;
@@ -2168,6 +2194,30 @@ This is a fully client-side application. Your content never leaves your browser
     });
   }
 
+  function insertAlignmentBlock(align) {
+    const allowedAlignments = new Set(['left', 'center', 'right']);
+    const isAllowed = allowedAlignments.has(align);
+    if (!isAllowed) {
+      console.warn('Unsupported alignment:', align);
+      return;
+    }
+    const safeAlign = align;
+    const value = markdownEditor.value;
+    const start = markdownEditor.selectionStart;
+    const end = markdownEditor.selectionEnd;
+    const selected = value.slice(start, end);
+    const hasSelection = start !== end;
+    const blockStart = `<div align="${safeAlign}">\n`;
+    const blockEnd = `\n</div>`;
+    const block = `${blockStart}${hasSelection ? selected : ''}${blockEnd}`;
+    const needsLeadingBreak = start > 0 && value[start - 1] !== '\n';
+    const needsTrailingBreak = end < value.length && value[end] !== '\n';
+    const replacement = (needsLeadingBreak ? '\n' : '') + block + (needsTrailingBreak ? '\n' : '');
+    const contentStart = start + (needsLeadingBreak ? 1 : 0) + blockStart.length;
+    const contentEnd = contentStart + (hasSelection ? selected.length : 0);
+    replaceEditorRange(start, end, replacement, contentStart, hasSelection ? contentEnd : contentStart);
+  }
+
   function insertMarkdownBlock(block, startOverride, endOverride) {
     const value = markdownEditor.value;
     const start = typeof startOverride === 'number' ? startOverride : markdownEditor.selectionStart;
@@ -3348,6 +3398,9 @@ This is a fully client-side application. Your content never leaves your browser
     else if (action === 'strike') wrapEditorSelection('~~', '~~', 'struck text');
     else if (action === 'italic') wrapEditorSelection('*', '*', 'italic text');
     else if (action === 'quote') transformEditorLines(function(line) { return line ? '> ' + line.replace(/^>\s?/, '') : '>'; });
+    else if (action === 'align-left') insertAlignmentBlock('left');
+    else if (action === 'align-center') insertAlignmentBlock('center');
+    else if (action === 'align-right') insertAlignmentBlock('right');
     else if (action === 'title-case') transformSelectionOrCurrentLine(toTitleCase);
     else if (action === 'uppercase') transformSelectionOrCurrentLine(function(text) { return text.toUpperCase(); });
     else if (action === 'lowercase') transformSelectionOrCurrentLine(function(text) { return text.toLowerCase(); });
@@ -3530,6 +3583,19 @@ This is a fully client-side application. Your content never leaves your browser
   mobileExportHtml.addEventListener("click", () => exportHtml.click());
   mobileExportPdf.addEventListener("click", () => exportPdf.click());
   mobileCopyMarkdown.addEventListener("click", () => copyMarkdownButton.click());
+  if (mobileDirectionToggle) {
+    mobileDirectionToggle.addEventListener("click", () => {
+      if (directionToggle) {
+        directionToggle.click();
+      } else {
+        const direction =
+          document.documentElement.getAttribute("dir") === "rtl" ? "ltr" : "rtl";
+        document.documentElement.setAttribute("dir", direction);
+        saveGlobalState({ direction });
+        updateDirectionToggleUI(direction);
+      }
+    });
+  }
   mobileThemeToggle.addEventListener("click", () => {
     themeToggle.click();
     mobileThemeToggle.innerHTML = themeToggle.innerHTML + " Toggle Dark Mode";
@@ -3635,6 +3701,15 @@ This is a fully client-side application. Your content never leaves your browser
   });
   previewPane.addEventListener("scroll", syncPreviewToEditor);
   toggleSyncButton.addEventListener("click", toggleSyncScrolling);
+  if (directionToggle) {
+    directionToggle.addEventListener("click", function () {
+      const direction =
+        document.documentElement.getAttribute("dir") === "rtl" ? "ltr" : "rtl";
+      document.documentElement.setAttribute("dir", direction);
+      saveGlobalState({ direction });
+      updateDirectionToggleUI(direction);
+    });
+  }
   themeToggle.addEventListener("click", function () {
     const theme =
       document.documentElement.getAttribute("data-theme") === "dark"
@@ -3720,7 +3795,7 @@ This is a fully client-side application. Your content never leaves your browser
       const html = marked.parse(markdown);
       const sanitizedHtml = DOMPurify.sanitize(html, {
         ADD_TAGS: ['mjx-container'], 
-        ADD_ATTR: ['id', 'class', 'style']
+        ADD_ATTR: ['id', 'class', 'style', 'align']
       });
       const tempContainer = document.createElement("div");
       tempContainer.innerHTML = sanitizedHtml;
@@ -4338,7 +4413,7 @@ This is a fully client-side application. Your content never leaves your browser
       const html = marked.parse(markdown);
       const sanitizedHtml = DOMPurify.sanitize(html, {
         ADD_TAGS: ['mjx-container', 'svg', 'path', 'g', 'marker', 'defs', 'pattern', 'clipPath'],
-        ADD_ATTR: ['id', 'class', 'style', 'viewBox', 'd', 'fill', 'stroke', 'transform', 'marker-end', 'marker-start']
+        ADD_ATTR: ['id', 'class', 'style', 'align', 'viewBox', 'd', 'fill', 'stroke', 'transform', 'marker-end', 'marker-start']
       });
 
       const tempElement = document.createElement("div");
diff --git a/styles.css b/styles.css
index efa662b..ce26589 100644
--- a/styles.css
+++ b/styles.css
@@ -2547,3 +2547,69 @@ a:focus {
   background-color: var(--button-bg);
   white-space: nowrap;
 }
+
+/* ========================================
+   RTL SUPPORT
+   ======================================== */
+
+[dir="rtl"] body {
+  direction: rtl;
+}
+
+[dir="rtl"] #markdown-editor,
+[dir="rtl"] .markdown-body {
+  direction: rtl;
+  text-align: right;
+}
+
+[dir="rtl"] .markdown-body pre,
+[dir="rtl"] .markdown-body code,
+[dir="rtl"] .fm-complex {
+  direction: ltr;
+  text-align: left;
+}
+
+[dir="rtl"] .line-numbers {
+  left: auto;
+  right: 20px;
+  padding: 10px 0 10px 8px;
+  text-align: left;
+  border-right: none;
+  border-left: 1px solid var(--border-color);
+}
+
+[dir="rtl"] #markdown-editor {
+  padding-left: 10px;
+  padding-right: calc(10px + var(--line-number-gutter));
+}
+
+[dir="rtl"] .editor-highlight-layer {
+  inset: 20px calc(20px + var(--line-number-gutter)) 20px 0;
+}
+
+[dir="rtl"] .mobile-menu-item,
+[dir="rtl"] .tab-menu-item,
+[dir="rtl"] .modal-header .reset-modal-message,
+[dir="rtl"] .reset-modal-field,
+[dir="rtl"] .alert-option,
+[dir="rtl"] .github-import-error,
+[dir="rtl"] #github-import-modal .reset-modal-message,
+[dir="rtl"] .github-tree-file-btn,
+[dir="rtl"] .frontmatter-table td {
+  text-align: right;
+}
+
+[dir="rtl"] .github-import-tree ul {
+  padding-left: 0;
+  padding-right: 18px;
+}
+
+[dir="rtl"] .github-import-tree > ul {
+  padding-right: 4px;
+}
+
+[dir="rtl"] .markdown-body .markdown-alert,
+[dir="rtl"] .alert-preview .markdown-alert {
+  border-left: 0;
+  border-right: 0.25em solid currentColor;
+}