Feature/v2/more landing zones (#4575)

# Description of Changes

<!--
Please provide a summary of the changes, including:

- What was changed
- Why the change was made
- Any challenges encountered

Closes #(issue_number)
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---

## Checklist

### General

- [ ] I have read the [Contribution
Guidelines](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/CONTRIBUTING.md)
- [ ] I have read the [Stirling-PDF Developer
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/DeveloperGuide.md)
(if applicable)
- [ ] I have read the [How to add new languages to
Stirling-PDF](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md)
(if applicable)
- [ ] I have performed a self-review of my own code
- [ ] My changes generate no new warnings

### Documentation

- [ ] I have updated relevant docs on [Stirling-PDF's doc
repo](https://github.com/Stirling-Tools/Stirling-Tools.github.io/blob/main/docs/)
(if functionality has heavily changed)
- [ ] I have read the section [Add New Translation
Tags](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md#add-new-translation-tags)
(for new translation tags only)

### UI Changes (if applicable)

- [ ] Screenshots or videos demonstrating the UI changes are attached
(e.g., as comments or direct attachments in the PR)

### Testing (if applicable)

- [ ] I have tested my changes locally. Refer to the [Testing
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/DeveloperGuide.md#6-testing)
for more details.

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

frontend/src/components/fileEditor/FileEditor.module.css

@@ -304,4 +304,84 @@
 /* Light mode selected header stroke override */
 :global([data-mantine-color-scheme="light"]) .card[data-selected="true"] {
   outline-color: #3B4B6E;
+}
+
+/* =========================
+   Add File Card Styles
+   ========================= */
+
+.addFileCard {
+  background: var(--file-card-bg);
+  border: 2px dashed var(--border-default);
+  border-radius: 0.0625rem;
+  cursor: pointer;
+  transition: all 0.18s ease;
+  max-width: 100%;
+  max-height: 100%;
+  overflow: hidden;
+  margin-left: 0.5rem;
+  margin-right: 0.5rem;
+  opacity: 0.7;
+}
+
+.addFileCard:hover {
+  opacity: 1;
+  border-color: var(--color-blue-500);
+  box-shadow: var(--shadow-md);
+  transform: translateY(-2px);
+}
+
+.addFileCard:focus {
+  outline: 2px solid var(--color-blue-500);
+  outline-offset: 2px;
+}
+
+.addFileHeader {
+  background: var(--bg-subtle);
+  color: var(--text-secondary);
+  border-bottom: 1px solid var(--border-default);
+}
+
+.addFileCard:hover .addFileHeader {
+  background: var(--color-blue-500);
+  color: white;
+}
+
+.addFileContent {
+  flex: 1;
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  justify-content: center;
+  padding: 1.5rem 1rem;
+  gap: 0.5rem;
+}
+
+.addFileIcon {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  width: 5rem;
+  height: 5rem;
+  border-radius: 50%;
+  background: var(--bg-subtle);
+  transition: background-color 0.18s ease;
+}
+
+.addFileCard:hover .addFileIcon {
+  background: var(--color-blue-50);
+}
+
+.addFileText {
+  font-weight: 500;
+  transition: color 0.18s ease;
+}
+
+.addFileCard:hover .addFileText {
+  color: var(--text-primary);
+}
+
+.addFileSubtext {
+  font-size: 0.875rem;
+  opacity: 0.8;
 }