diff --git a/index.html b/index.html
index 4a3fe34..9f7047a 100644
--- a/index.html
+++ b/index.html
@@ -481,6 +481,51 @@ <h3 class="modal-section-title">Open-source credits</h3>
           </div>
         </div>
 
+        <!-- Share Modal -->
+        <div id="share-modal" class="reset-modal-overlay modal-overlay" role="dialog" aria-modal="true" aria-labelledby="share-modal-title" aria-hidden="true" style="display:none;">
+          <div class="reset-modal-box reset-modal-box--wide modal-box">
+            <div class="modal-header">
+              <p id="share-modal-title" class="reset-modal-message">Share Document</p>
+              <button type="button" class="modal-close-btn" id="share-modal-close-icon" aria-label="Close share dialog">
+                <i class="bi bi-x-lg"></i>
+              </button>
+            </div>
+            <div class="modal-body">
+              <p class="share-modal-description">Choose how recipients can interact with this document.</p>
+              <div class="share-mode-cards">
+                <label class="share-mode-card" id="share-card-view" for="share-mode-view">
+                  <input type="radio" id="share-mode-view" name="share-mode" value="view" checked />
+                  <span class="share-card-icon"><i class="bi bi-eye"></i></span>
+                  <span class="share-card-body">
+                    <span class="share-card-title">View only</span>
+                    <span class="share-card-desc">Opens in preview mode. The editor is hidden.</span>
+                  </span>
+                  <span class="share-card-check"><i class="bi bi-check-lg"></i></span>
+                </label>
+                <label class="share-mode-card" id="share-card-edit" for="share-mode-edit">
+                  <input type="radio" id="share-mode-edit" name="share-mode" value="edit" />
+                  <span class="share-card-icon"><i class="bi bi-pencil-square"></i></span>
+                  <span class="share-card-body">
+                    <span class="share-card-title">Edit</span>
+                    <span class="share-card-desc">Opens in split editor + preview mode.</span>
+                  </span>
+                  <span class="share-card-check"><i class="bi bi-check-lg"></i></span>
+                </label>
+              </div>
+              <div class="share-url-row">
+                <input type="text" id="share-url-input" class="rename-modal-input share-url-input" readonly placeholder="Generating link…" aria-label="Share URL" />
+                <button class="reset-modal-btn share-copy-btn" id="share-copy-btn" title="Copy link">
+                  <i class="bi bi-clipboard"></i>
+                </button>
+              </div>
+              <p class="share-modal-notice"><i class="bi bi-info-circle"></i> The entire document is encoded in the URL. No data is sent to any server.</p>
+            </div>
+            <div class="reset-modal-actions">
+              <button class="reset-modal-btn reset-modal-cancel" id="share-modal-close">Close</button>
+            </div>
+          </div>
+        </div>
+
         <!-- Rename Modal -->
         <div id="rename-modal" class="reset-modal-overlay" role="dialog" aria-modal="true" aria-labelledby="rename-modal-title" style="display:none;">
           <div class="reset-modal-box reset-modal-box--wide">
@@ -717,4 +762,4 @@ <h3 class="modal-section-title">Open-source credits</h3>
     <script src="https://cdnjs.cloudflare.com/ajax/libs/bootstrap/5.3.2/js/bootstrap.bundle.min.js"></script>
     <script src="script.js"></script>
 </body>
-</html>
+</html>
\ No newline at end of file
diff --git a/script.js b/script.js
index a8cf5e3..8cd4773 100644
--- a/script.js
+++ b/script.js
@@ -665,7 +665,10 @@ document.addEventListener("DOMContentLoaded", function () {
           return markdown;
         }
         resetExtendedMarkdownState();
-        return applyFootnotes(extractFootnoteDefinitions(markdown));
+        // ✅ Replace escaped dollar signs before marked.js strips the backslash.
+        // This prevents MathJax from treating lone $ as a math delimiter.
+        const protectedMarkdown = markdown.replace(/\\\$/g, '&#36;');
+        return applyFootnotes(extractFootnoteDefinitions(protectedMarkdown));
       },
     },
   });
@@ -5009,64 +5012,151 @@ This is a fully client-side application. Your content never leaves your browser
     return new TextDecoder().decode(pako.inflate(bytes));
   }
 
-  function copyShareUrl(btn) {
+  // ============================================
+  // Share Modal
+  // ============================================
+
+  const shareModal        = document.getElementById('share-modal');
+  const shareModalCloseX  = document.getElementById('share-modal-close-icon');
+  const shareModalClose   = document.getElementById('share-modal-close');
+  const shareUrlInput     = document.getElementById('share-url-input');
+  const shareCopyBtn      = document.getElementById('share-copy-btn');
+  const shareModeView     = document.getElementById('share-mode-view');
+  const shareModeEdit     = document.getElementById('share-mode-edit');
+  const shareCardView     = document.getElementById('share-card-view');
+  const shareCardEdit     = document.getElementById('share-card-edit');
+
+  function buildShareUrl(mode) {
     const markdownText = markdownEditor.value;
     let encoded;
     try {
       encoded = encodeMarkdownForShare(markdownText);
     } catch (e) {
-      console.error("Share encoding failed:", e);
-      alert("Failed to encode content for sharing: " + e.message);
+      console.error('Share encoding failed:', e);
+      return null;
+    }
+    // mode=view  →  #share=<encoded>   (opens preview-only)
+    // mode=edit  →  #share=<encoded>&edit=1
+    const base = window.location.origin + window.location.pathname + '#share=' + encoded;
+    return mode === 'edit' ? base + '&edit=1' : base;
+  }
+
+  function updateShareUrlField() {
+    const mode = shareModeView.checked ? 'view' : 'edit';
+    const url = buildShareUrl(mode);
+    if (!url) {
+      shareUrlInput.value = 'Error generating link.';
+      shareCopyBtn.disabled = true;
       return;
     }
+    const tooLarge = url.length > MAX_SHARE_URL_LENGTH;
+    if (tooLarge) {
+      shareUrlInput.value = 'Document too large to share via URL.';
+      shareCopyBtn.disabled = true;
+    } else {
+      shareUrlInput.value = url;
+      shareCopyBtn.disabled = false;
+    }
+  }
 
-    const shareUrl = window.location.origin + window.location.pathname + '#share=' + encoded;
-    const tooLarge = shareUrl.length > MAX_SHARE_URL_LENGTH;
+  function openShareModal() {
+    // Reset to view-only by default each time
+    shareModeView.checked = true;
+    syncShareCardStyles();
+    updateShareUrlField();
+    shareModal.style.display = '';
+    requestAnimationFrame(() => {
+      shareModal.classList.add('is-visible');
+      shareModal.setAttribute('aria-hidden', 'false');
+    });
+  }
 
-    const originalHTML = btn.innerHTML;
-    const copiedHTML = '<i class="bi bi-check-lg"></i> Copied!';
+  function closeShareModal() {
+    shareModal.classList.remove('is-visible');
+    shareModal.setAttribute('aria-hidden', 'true');
+    shareModal.addEventListener('transitionend', function handler() {
+      shareModal.style.display = 'none';
+      shareModal.removeEventListener('transitionend', handler);
+    });
+  }
+
+  function syncShareCardStyles() {
+    if (shareModeView.checked) {
+      shareCardView.classList.add('is-selected');
+      shareCardEdit.classList.remove('is-selected');
+    } else {
+      shareCardEdit.classList.add('is-selected');
+      shareCardView.classList.remove('is-selected');
+    }
+  }
+
+  shareModeView.addEventListener('change', function () {
+    syncShareCardStyles();
+    updateShareUrlField();
+  });
+  shareModeEdit.addEventListener('change', function () {
+    syncShareCardStyles();
+    updateShareUrlField();
+  });
+
+  shareCopyBtn.addEventListener('click', function () {
+    const url = shareUrlInput.value;
+    if (!url || shareCopyBtn.disabled) return;
 
     function onCopied() {
-      if (!tooLarge) {
-        window.location.hash = 'share=' + encoded;
-      }
-      btn.innerHTML = copiedHTML;
-      setTimeout(() => { btn.innerHTML = originalHTML; }, 2000);
+      const orig = shareCopyBtn.innerHTML;
+      shareCopyBtn.innerHTML = '<i class="bi bi-check-lg"></i>';
+      setTimeout(() => { shareCopyBtn.innerHTML = orig; }, 2000);
     }
 
     if (navigator.clipboard && window.isSecureContext) {
-      navigator.clipboard.writeText(shareUrl).then(onCopied).catch(() => {
-        // clipboard.writeText failed; nothing further to do in secure context
-      });
+      navigator.clipboard.writeText(url).then(onCopied).catch(() => {});
     } else {
       try {
-        const tempInput = document.createElement("textarea");
-        tempInput.value = shareUrl;
-        document.body.appendChild(tempInput);
-        tempInput.select();
-        document.execCommand("copy");
-        document.body.removeChild(tempInput);
+        const tmp = document.createElement('textarea');
+        tmp.value = url;
+        document.body.appendChild(tmp);
+        tmp.select();
+        document.execCommand('copy');
+        document.body.removeChild(tmp);
         onCopied();
-      } catch (_) {
-        // copy failed silently
-      }
+      } catch (_) {}
     }
-  }
+  });
+
+  shareModalCloseX.addEventListener('click', closeShareModal);
+  shareModalClose.addEventListener('click', closeShareModal);
+  shareModal.addEventListener('click', function (e) {
+    if (e.target === shareModal) closeShareModal();
+  });
+  document.addEventListener('keydown', function (e) {
+    if (e.key === 'Escape' && shareModal.classList.contains('is-visible')) closeShareModal();
+  });
 
-  shareButton.addEventListener("click", function () { copyShareUrl(shareButton); });
-  mobileShareButton.addEventListener("click", function () { copyShareUrl(mobileShareButton); });
+  shareButton.addEventListener('click', openShareModal);
+  mobileShareButton.addEventListener('click', openShareModal);
 
   function loadFromShareHash() {
     if (typeof pako === 'undefined') return;
     const hash = window.location.hash;
     if (!hash.startsWith('#share=')) return;
-    const encoded = hash.slice('#share='.length);
+
+    // Parse encoded content and optional &edit=1 flag.
+    // Hash format: #share=<encoded>  or  #share=<encoded>&edit=1
+    const rest = hash.slice('#share='.length);
+    const ampIdx = rest.indexOf('&');
+    const encoded = ampIdx === -1 ? rest : rest.slice(0, ampIdx);
+    const params = ampIdx === -1 ? '' : rest.slice(ampIdx + 1);
+    const isEdit = params.split('&').includes('edit=1');
+
     if (!encoded) return;
     try {
       const decoded = decodeMarkdownFromShare(encoded);
       markdownEditor.value = decoded;
       renderMarkdown();
       saveCurrentTabState();
+      // Apply the correct view mode: edit=1 → split, default → preview only
+      setViewMode(isEdit ? 'split' : 'preview');
     } catch (e) {
       console.error("Failed to load shared content:", e);
       alert("The shared URL could not be decoded. It may be corrupted or incomplete.");
@@ -5495,4 +5585,4 @@ This is a fully client-side application. Your content never leaves your browser
       container.appendChild(toolbar);
     });
   }
-});
+});
\ No newline at end of file
diff --git a/styles.css b/styles.css
index 36c2a12..dff24c7 100644
--- a/styles.css
+++ b/styles.css
@@ -2686,3 +2686,125 @@ a:focus {
   border-left: 0;
   border-right: 0.25em solid currentColor;
 }
+
+/* ============================================
+   SHARE MODAL
+   ============================================ */
+
+.share-modal-description {
+  font-size: 13px;
+  color: var(--text-secondary, #57606a);
+  margin: 0;
+}
+
+.share-mode-cards {
+  display: flex;
+  flex-direction: column;
+  gap: 8px;
+}
+
+.share-mode-card {
+  display: flex;
+  align-items: center;
+  gap: 12px;
+  padding: 12px 14px;
+  border-radius: 8px;
+  border: 1px solid var(--border-color);
+  background: var(--bg-color);
+  cursor: pointer;
+  transition: border-color 0.15s ease, background-color 0.15s ease;
+  user-select: none;
+}
+
+.share-mode-card:hover {
+  border-color: var(--accent-color);
+  background: var(--button-hover);
+}
+
+.share-mode-card.is-selected {
+  border-color: var(--accent-color);
+  background: color-mix(in srgb, var(--accent-color) 8%, transparent);
+}
+
+.share-mode-card input[type="radio"] {
+  display: none;
+}
+
+.share-card-icon {
+  font-size: 18px;
+  width: 28px;
+  text-align: center;
+  color: var(--text-secondary, #57606a);
+  flex-shrink: 0;
+}
+
+.share-mode-card.is-selected .share-card-icon {
+  color: var(--accent-color);
+}
+
+.share-card-body {
+  display: flex;
+  flex-direction: column;
+  gap: 2px;
+  flex: 1;
+  min-width: 0;
+}
+
+.share-card-title {
+  font-size: 13px;
+  font-weight: 600;
+  color: var(--text-color);
+}
+
+.share-card-desc {
+  font-size: 12px;
+  color: var(--text-secondary, #57606a);
+}
+
+.share-card-check {
+  width: 18px;
+  text-align: center;
+  color: var(--accent-color);
+  opacity: 0;
+  transition: opacity 0.15s ease;
+  flex-shrink: 0;
+}
+
+.share-mode-card.is-selected .share-card-check {
+  opacity: 1;
+}
+
+.share-url-row {
+  display: flex;
+  gap: 8px;
+  align-items: center;
+}
+
+.share-url-input {
+  flex: 1;
+  font-size: 12px;
+  font-family: var(--font-mono, monospace);
+  color: var(--text-secondary, #57606a);
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}
+
+.share-copy-btn {
+  flex-shrink: 0;
+  padding: 6px 10px;
+}
+
+.share-copy-btn:disabled {
+  opacity: 0.5;
+  cursor: not-allowed;
+}
+
+.share-modal-notice {
+  font-size: 11px;
+  color: var(--text-secondary, #57606a);
+  margin: 0;
+  display: flex;
+  align-items: center;
+  gap: 5px;
+}
\ No newline at end of file