diff --git a/README.md b/README.md
index f2259d1..34c2749 100644
--- a/README.md
+++ b/README.md
@@ -65,15 +65,15 @@ moffee is an open-source slide maker that transforms markdown documents into cle
 
 One of moffee's strengths is using dividers to organize text and images effectively.
 
-___
+===
 
 - Use `---` to trigger page breaks.
-- Use `***` to arrange elements horizontally.
-- Use `___` to split elements vertically.
+- Use `<->` to arrange elements horizontally.
+- Use `===` to split elements vertically.
 
 moffee automatically adjusts element sizes to accommodate large blocks of text or complex illustrations.
 
-***
+<->
 
 ![blue coffee](coffee.png)
 ```
@@ -158,23 +158,23 @@ Text on the next slide.
 
 You'll notice the second slide shares the `Page 1` title. moffee selects the most suitable title for each slide.
 
-In addition to `---`, moffee supports `***` and `___` for in-slide layout. Use `***` to separate elements horizontally:
+In addition to `---`, moffee supports `<->` and `===` for in-slide layout. Use `<->` to separate elements horizontally:
 
 ```markdown
 Text on the left.
-***
+<->
 ![Image on the right](https://placehold.co/600x400)
 ```
 
-`___` places elements vertically and takes precedence over `***`. Use them together for flexible layouts:
+`===` places elements vertically and takes precedence over `<->`. Use them together for flexible layouts:
 
 ```markdown
 Top bun
-___
+===
 Patty on the left
-***
+<->
 Lettuce on the right
-___
+===
 Bottom bun
 ```
 
diff --git a/SECURITY.md b/SECURITY.md
index 0991fbc..32a4411 100644
--- a/SECURITY.md
+++ b/SECURITY.md
@@ -12,7 +12,7 @@ currently being supported with security updates.
 
 ## Reporting a Vulnerability
 
-If you discover a security vulnerability, please report it by creating an issue in our project's Issue Tracker. 
+If you discover a security vulnerability, please report it by creating an issue in our project's Issue Tracker.
 
 When reporting, please provide:
 - A brief description of the vulnerability
diff --git a/docs/getting-started.md b/docs/getting-started.md
index 28acefb..ef60b0b 100644
--- a/docs/getting-started.md
+++ b/docs/getting-started.md
@@ -53,23 +53,23 @@ Text on the next slide.
 
 You'll notice the second slide shares the `Page 1` title. moffee selects the most suitable title for each slide.
 
-In addition to `---`, moffee supports `***` and `___` for in-slide layout. Use `***` to separate elements horizontally:
+In addition to `---`, moffee supports `<->` and `===` for in-slide layout. Use `<->` to separate elements horizontally:
 
 ```markdown
 Text on the left.
-***
+<->
 ![Image on the right](https://placehold.co/600x400)
 ```
 
-`___` places elements vertically and takes precedence over `***`. Use them together for flexible layouts:
+`===` places elements vertically and takes precedence over `<->`. Use them together for flexible layouts:
 
 ```markdown
 Top bun
-___
+===
 Patty on the left
-***
+<->
 Lettuce on the right
-___
+===
 Bottom bun
 ```
 
diff --git a/docs/syntax.md b/docs/syntax.md
index cd7ad8c..a2b490d 100644
--- a/docs/syntax.md
+++ b/docs/syntax.md
@@ -15,7 +15,7 @@ Use headers to structure your presentation:
 Emphasize key points:
 - *Italic*: `*italic*` or `_italic_`
 - **Bold**: `**bold**` or `__bold__`
-- ***Bold and Italic***: `***bold and italic***`
+- <->Bold and Italic<->: `<->bold and italic<->`
 
 ### Lists
 Organize information clearly:
@@ -131,18 +131,18 @@ Content for slide 2
 ### In-slide Layout
 
 #### Horizontal Separation
-Create columns with `***`:
+Create columns with `<->`:
 ```markdown
 Left column content
-***
+<->
 Right column content
 ```
 
 #### Vertical Separation
-Stack content with `___`:
+Stack content with `===`:
 ```markdown
 Top section
-___
+===
 Bottom section
 ```
 
@@ -150,11 +150,11 @@ Bottom section
 Create complex layouts:
 ```markdown
 Top row
-___
+===
 Left column
-***
+<->
 Right column
-___
+===
 Bottom row
 ```
 
diff --git a/moffee/compositor.py b/moffee/compositor.py
index 37c2383..ce1d1ec 100644
--- a/moffee/compositor.py
+++ b/moffee/compositor.py
@@ -114,9 +114,9 @@ def chunk(self) -> Chunk:
         """
         Split raw_md into chunk tree
         Chunk tree branches when in-page divider is met.
-        - adjacent "***"s create chunk with horizontal direction
-        - adjacent "___" create chunk with vertical direction
-        "___" possesses higher priority than "***"
+        - adjacent "<->"s create chunk with horizontal direction
+        - adjacent "===" create chunk with vertical direction
+        "===" possesses higher priority than "<->"
 
         :return: Root of the chunk tree
         """
@@ -133,12 +133,12 @@ def split_by_div(text, type) -> List[Chunk]:
                     strs[-1] += line + "\n"
             return [Chunk(paragraph=s) for s in strs]
 
-        # collect "___"
-        vchunks = split_by_div(self.raw_md, "_")
-        # split by "***" if possible
+        # collect "==="
+        vchunks = split_by_div(self.raw_md, "=")
+        # split by "<->" if possible
         for i in range(len(vchunks)):
-            hchunks = split_by_div(vchunks[i].paragraph, "*")
-            if len(hchunks) > 1:  # found ***
+            hchunks = split_by_div(vchunks[i].paragraph, "<")
+            if len(hchunks) > 1:  # found <->
                 vchunks[i] = Chunk(children=hchunks, type=Type.NODE)
 
         if len(vchunks) == 1:
@@ -259,7 +259,7 @@ def composite(document: str) -> List[Page]:
 
     Splitting criteria:
     - New h1/h2/h3 header (except when following another header)
-    - "---" Divider (___, ***, +++ not count)
+    - "---" Divider (===, <->, +++ not count)
 
     :param document: Input markdown document as a string.
     :param document_path: Optional string, will be used to redirect url in documents if given.
diff --git a/moffee/utils/md_helper.py b/moffee/utils/md_helper.py
index 034742c..f779c96 100644
--- a/moffee/utils/md_helper.py
+++ b/moffee/utils/md_helper.py
@@ -40,26 +40,30 @@ def is_empty(line: str) -> bool:
     return is_comment(line) or line.strip() == ""
 
 
-def is_divider(line: str, type=None) -> bool:
+def is_divider(line: str, type: Optional[str] = None) -> bool:
     """
-    Determines if a given line is a Markdown divider (horizontal rule).
-    Markdown dividers are three or more hyphens, asterisks, or underscores,
-    without any other characters except spaces.
+    Determines if a given line is a Markdown divider (horizontal rule, vertical divider, or horizontal divider).
 
     :param line: The line to check
-    :param type: Which type to match, str. e.g. "*" to match "***" only. Defaults to "", match any of "*", "-" and "_".
+    :param type: Which type to match, str. e.g. "*" to match "***" only, "<" to match "<->", "=" to match "===".
+                 Defaults to None, match any of "*", "-", "_", "<" or "=".
     :return: True if the line is a divider, False otherwise
     """
     stripped_line = line.strip()
-    if len(stripped_line) < 3:
-        return False
     if type is None:
-        type = "-*_"
-
-    assert type in "-*_", "type must be either '*', '-' or '_'"
-    return all(char in type for char in stripped_line) and any(
-        char * 3 in stripped_line for char in type
-    )
+        return bool(re.match(r"^\s*([\*\-\_]{3,}|<->|={3,})\s*$", stripped_line))
+    elif type == "*":
+        return bool(re.match(r"^\s*\*{3,}\s*$", stripped_line))
+    elif type == "-":
+        return bool(re.match(r"^\s*\-{3,}\s*$", stripped_line))
+    elif type == "_":
+        return bool(re.match(r"^\s*_{3,}\s*$", stripped_line))
+    elif type == "<":
+        return bool(re.match(r"^\s*<->\s*$", stripped_line))
+    elif type == "=":
+        return bool(re.match(r"^\s*={3,}\s*$", stripped_line))
+    else:
+        return False
 
 
 def contains_image(line: str) -> bool:
diff --git a/pyproject.toml b/pyproject.toml
index 9a44973..2aa91d2 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -18,6 +18,7 @@ pymdown-extensions = "^10.8.1"
 livereload = "^2.7.0"
 click = "^8.1.7"
 beautifulsoup4 = "^4.12.3"
+myst-parser = "^4.0.0"
 
 [tool.poetry.dev-dependencies]
 pytest = "^8.2.2"
diff --git a/tests/test_builder.py b/tests/test_builder.py
index e1ff007..75c892c 100644
--- a/tests/test_builder.py
+++ b/tests/test_builder.py
@@ -24,11 +24,11 @@ def setup_test_env():
 ![Image-1](image.png)
 ---
 Paragraph 1
-___
+===
 Paragraph 2
-***
+<->
 Paragraph 3
-***
+<->
 ![Image-2](image2.png)
     """
     with tempfile.TemporaryDirectory() as temp_dir:
diff --git a/tests/test_md_helper.py b/tests/test_md_helper.py
index 51523ab..8681a20 100644
--- a/tests/test_md_helper.py
+++ b/tests/test_md_helper.py
@@ -40,6 +40,15 @@ def test_is_divider():
     assert is_divider("***", type="*") is True
     assert is_divider("***", type="-") is False
     assert is_divider("* * *", type="*") is False
+    assert is_divider("<->") is True
+    assert is_divider("<->", type="<") is True
+    assert is_divider("<->", type="-") is False
+    assert is_divider("===") is True
+    assert is_divider("===", type="=") is True
+    assert is_divider("===", type="*") is False
+    assert is_divider("  ===  ") is True
+    assert is_divider("==") is False
+    assert is_divider("= = =") is False
 
 
 def test_contains_image():
diff --git a/tests/test_paginate.py b/tests/test_paginate.py
index c8660e1..50f1fd3 100644
--- a/tests/test_paginate.py
+++ b/tests/test_paginate.py
@@ -112,7 +112,7 @@ def test_page_splitting_on_dividers():
 Content 1
 ---
 Content 2
-***
+<->
 Content 3
     """
     pages = composite(doc)
@@ -126,7 +126,7 @@ def test_escaped_area_paging():
 ---
 Content 2
 ```
-***
+<->
 Content 3
     """
     pages = composite(doc)
@@ -139,7 +139,7 @@ def test_escaped_area_chunking():
 ---
 Content 2
 ```bash
-***
+<->
 Content 3
 ```
     """
@@ -198,7 +198,7 @@ def test_chunking_trivial():
 def test_chunking_vertical():
     doc = """
 Paragraph 1
-___
+===
 
 Paragraph 2
     """
@@ -213,10 +213,10 @@ def test_chunking_vertical():
 def test_chunking_horizontal():
     doc = """
 Paragraph 1
-***
+<->
 
 Paragraph 2
-***
+<->
     """
     pages = composite(doc)
     chunk = pages[0].chunk
@@ -231,11 +231,11 @@ def test_chunking_hybrid():
 Other Pages
 ---
 Paragraph 1
-___
+===
 Paragraph 2
-***
+<->
 Paragraph 3
-***
+<->
 Paragraph 4
     """
     pages = composite(doc)