diff --git a/app.py b/app.py
index c96f113..6b910da 100644
--- a/app.py
+++ b/app.py
@@ -40,7 +40,7 @@ HTML_FORM = '''
   }
   .form-card {
     background: #22282c;
-    padding: 2em 2.4em 1em 2em;
+    padding: 2em 2em 1em 2em;
     border-radius: 1.5em;
     box-shadow: 0 0 12px 0 #000a;
     min-width: 410px;
@@ -54,12 +54,14 @@ HTML_FORM = '''
   .markdown-ref {
     background: #22282c;
     border-radius: 1.2em;
-    box-shadow: 0 0 8px #0008;
-    padding: 1.3em 1.2em 1.1em 1.6em;
+    box-shadow: 0 0 12px 0 #000a;
+    padding: 2em 2em 1.5em 2em;
     color: #b6c8e0;
     font-size: 1.08em;
-    max-width: 410px;
     font-family: inherit;
+    box-sizing: border-box;
+    width: 100%;
+    max-width: 410px;
   }
   .markdown-ref h4 {
     margin: 0 0 0.4em 0;
@@ -102,10 +104,10 @@ HTML_FORM = '''
   .buttons {
     display: flex;
     gap: 1em;
-    align-items: center;
+    justify-content: center;
   }
   button[type=submit] {
-    background: linear-gradient(90deg, #8ee3c1, #35a7ff 85%);
+    background: linear-gradient(90deg, #8ee3c1, #35a7ff);
     color: #222;
     font-weight: bold;
     font-size: 1.12em;
@@ -122,6 +124,12 @@ HTML_FORM = '''
     filter: brightness(1.12);
     box-shadow: 0 4px 18px #2229;
   }
+
+  button[type=submit][name=print] {
+    background: linear-gradient(90deg, #ffeb3b, #ff9100);
+    color:#181c1f;
+  }
+
   .preview-card {
     background: #23282d;
     padding: 2em 1.4em 1em 1.4em;
@@ -137,7 +145,6 @@ HTML_FORM = '''
     margin-top: 1em;
     max-width: 100%;
     background: #fff;
-    border-radius: 0.6em;
     box-shadow: 0 0 8px 1px #111a;
   }
   .status-msg {
@@ -158,8 +165,92 @@ HTML_FORM = '''
     border-left: 4px solid #ff6384;
     box-shadow: 0 0 8px #22000690;
   }
+
+  @media (max-width: 1000px) {
+    .centered-flex {
+      flex-direction: column;
+      align-items: center;
+      height: auto;
+      gap: 1.6em;
+    }
+
+    .form-card,
+    .preview-card,
+    .markdown-ref {
+      min-width: auto;
+      max-width: 90vw;
+      width: 100%;
+      margin: 0.8em 0;
+    }
+  }
+
+  .print-frame {
+    position: relative;
+    background: #fff;
+    padding: 10px 15px;
+    margin-top: 1em;
+    overflow: hidden;
+  }
+
+  .print-frame::before,
+  .print-frame::after {
+    content: "";
+    position: absolute;
+    left: 0;
+    width: 101%;
+    height: 10px;
+    background: url('data:image/svg+xml;base64,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') repeat-x left;
+    background-size: 10px 384px;
+    z-index: 1;
+  }
+
+  .print-frame::before {
+    top: 0;
+  }
+
+  .print-frame::after {
+    bottom: 0;
+    transform: rotate(180deg);
+  }
+
+  .print-frame img {
+    display: block;
+    margin: 0 auto;
+    border-radius: 0;
+    box-shadow: none;
+    position: relative;
+    z-index: 2;
+  }
 </style>
 <div class="centered-flex">
+  <div class="form-card">
+    <center>
+    <h2 style="margin-top:0.2em;">😺 CatNote 🖨️</h2>
+    </center>
+    <form method=post enctype=multipart/form-data>
+      <textarea name=md placeholder="Ingrese Markdown aquí...">{{ default_md }}</textarea><br>
+      <div class="buttons">
+        <button type=submit name="generate">📷 Generar</button>
+        <button type=submit name="print">🖨️ Imprimir</button>
+      </div>
+    </form>
+    {% if printed %}
+      <div class="status-msg">✅ Enviado a impresora</div>
+    {% endif %}
+    {% if error %}
+      <div class="status-msg status-err">⚠️ {{ error }}</div>
+    {% endif %}
+  </div>
+  <div class="preview-card">
+    {% if img %}
+      <h3 style="margin-top:0.1em;margin-bottom:0.6em;">Vista previa</h3>
+      <div class="print-frame">
+        <img src="data:image/png;base64,{{ img }}">
+      </div>
+    {% else %}
+      <p style="opacity:.6;">Su vista previa aparecerá aquí</p>
+    {% endif %}
+  </div>
   <div class="markdown-ref">
     <h4>Referencia rápida de Markdown</h4>
     <ul>
@@ -174,35 +265,12 @@ HTML_FORM = '''
       <li><b>Salto de línea:</b> Deje una línea vacía</li>
     </ul>
   </div>
-  <div class="form-card">
-    <h2 style="margin-top:0.2em;">CatNotepad</h2>
-    <form method=post enctype=multipart/form-data>
-      <textarea name=md placeholder="Ingrese Markdown aquí...">{{ default_md }}</textarea><br>
-      <div class="buttons">
-        <button type=submit name="generate">📷 Generar</button>
-        <button type=submit name="print" style="background:linear-gradient(90deg,#ffeb3b 55%,#ff9100 95%);color:#181c1f;">🖨️ Imprimir</button>
-      </div>
-    </form>
-    {% if printed %}
-      <div class="status-msg">✅ Enviado a impresora</div>
-    {% endif %}
-    {% if error %}
-      <div class="status-msg status-err">⚠️ {{ error }}</div>
-    {% endif %}
-  </div>
-  <div class="preview-card">
-    {% if img %}
-      <h3 style="margin-top:0.1em;margin-bottom:0.6em;">Vista previa</h3>
-      <img src="data:image/png;base64,{{ img }}">
-    {% else %}
-      <p style="opacity:.6;">Su vista previa aparecerá aquí</p>
-    {% endif %}
-  </div>
 </div>
 '''
 
 def parse_line(line):
-    header_level = 0
+    if re.match(r'^\s*---\s*$', line):
+        return ('hr', [])
     header_match = re.match(r"^(#{1,3}) +(.*)", line)
     if header_match:
         header_level = len(header_match.group(1))
@@ -307,7 +375,9 @@ def render(md):
             lines_out.append(('blank', []))
             continue
         tag = parse_line(src_line)
-        if tag[0] == 'header':
+        if tag[0] == 'hr':
+            lines_out.append(('hr',))
+        elif tag[0] == 'header':
             header_level = tag[1]
             segments = tag[2]
             if header_level == 1:
@@ -346,13 +416,23 @@ def render(md):
             segments = tag[1]
             for wrapped in wrap_segments(segments, font, font_bold, font_italic, font_bolditalic, IMAGE_WIDTH):
                 lines_out.append(('text', wrapped, font, FONT_SIZE))
-    height = sum(item[3] if item[0] in ('header','text','bullet','ordered') else FONT_SIZE for item in lines_out) + 10
+
+    height = sum(
+        item[3] if item[0] in ('header', 'text', 'bullet', 'ordered') else
+        10 if item[0] == 'hr' else
+        FONT_SIZE
+        for item in lines_out
+    ) + 10
+
     image = Image.new("L", (IMAGE_WIDTH, height), 255)
     draw = ImageDraw.Draw(image)
     y = 0
     for item in lines_out:
         if item[0] == 'blank':
             y += FONT_SIZE
+        elif item[0] == 'hr':
+            draw.line((0, y + 5, IMAGE_WIDTH, y + 5), fill=0, width=2)
+            y += 10
         elif item[0] == 'header':
             segments, fnt, sz = item[1], item[2], item[3]
             x = 0
@@ -396,7 +476,6 @@ def render(md):
             y += sz
     return image
 
-
 @app.route("/", methods=["GET", "POST"])
 def index():
     img_data = None
@@ -436,4 +515,4 @@ def index():
         printed=printed, error=error)
 
 if __name__ == "__main__":
-    app.run(host="0.0.0.0")
+    app.run(host="0.0.0.0", debug=True)