diff --git a/src/popup.css b/src/popup.css
index b738083..4afa115 100644
--- a/src/popup.css
+++ b/src/popup.css
@@ -37,18 +37,29 @@
 html, body {
   width: 440px;
   min-height: 200px;
+  max-height: 600px;
   background: var(--bg);
   color: var(--text);
   font-family: var(--font);
   font-size: 13px;
   line-height: 1.5;
   overflow-x: hidden;
+  overflow-y: hidden;
 }
 
 /* ── Views ── */
 .view { display: flex; flex-direction: column; }
 .view.hidden { display: none !important; }
 
+/* ── Main view fills viewport, footer always visible ── */
+#view-main {
+  height: 600px;
+  max-height: 600px;
+  display: flex;
+  flex-direction: column;
+  overflow: hidden;
+}
+
 /* ── Loading ── */
 #view-loading {
   align-items: center;
@@ -170,13 +181,14 @@ header {
 .tab.active { color: var(--accent); border-bottom-color: var(--accent); }
 
 /* ── Tab panels ── */
-.tab-panel { flex: 1; }
-.tab-panel.hidden { display: none; }
+.tab-panel { flex: 1; min-height: 0; display: flex; flex-direction: column; }
+.tab-panel.hidden { display: none !important; }
 
 #md-editor {
   display: block;
   width: 100%;
-  height: 260px;
+  flex: 1;
+  min-height: 0;
   background: var(--bg);
   border: none;
   border-bottom: 1px solid var(--border);
@@ -191,7 +203,8 @@ header {
 #md-editor::placeholder { color: var(--text-muted); }
 
 .preview-body {
-  height: 260px;
+  flex: 1;
+  min-height: 0;
   overflow-y: auto;
   padding: 14px 16px;
   border-bottom: 1px solid var(--border);
diff --git a/src/popup.html b/src/popup.html
index d51560a..d1635de 100644
--- a/src/popup.html
+++ b/src/popup.html
@@ -57,14 +57,14 @@
     </div>
 
     <!-- edit panel -->
-    <div id="tab-edit" class="tab-panel flex flex-col h-96 border-b border-gray-100 dark:border-gray-800">
-      <textarea rows="14" id="md-editor" spellcheck="false" placeholder="Markdown content…" class="flex-1 w-full p-3 text-sm resize-none focus:outline-none focus:ring-1 focus:ring-emerald-100 dark:focus:ring-emerald-900/30 bg-transparent text-inherit"></textarea>
-      <div id="char-counter" class="char-counter text-right px-3 py-1 text-[10px] text-gray-400">0 chars</div>
+    <div id="tab-edit" class="tab-panel flex flex-col flex-1 min-h-0">
+      <textarea id="md-editor" spellcheck="false" placeholder="Markdown content…"></textarea>
+      <div id="char-counter" class="char-counter">0 chars</div>
     </div>
 
     <!-- preview panel -->
-    <div id="tab-preview" class="tab-panel hidden h-64 overflow-y-auto p-3 border-b border-gray-100 dark:border-gray-800">
-      <div id="md-preview" class="preview-body prose prose-sm dark:prose-invert max-w-none"></div>
+    <div id="tab-preview" class="tab-panel hidden flex flex-col flex-1 min-h-0">
+      <div id="md-preview" class="preview-body"></div>
     </div>
 
     <!-- images section -->