diff --git a/core/slice.py b/core/slice.py
index a81a075..70b50b3 100644
--- a/core/slice.py
+++ b/core/slice.py
@@ -103,7 +103,7 @@ class SlicePaths(list[np.ndarray]):
         
         return new_paths
 
-    def offset_curve(self, distance: float, join_style: str = 'round', rotation: Any = None) -> SlicePaths:
+    def offset_curve(self, distance: float, join_style: Literal['round', 'mitre'] = 'round', rotation: Any = None) -> SlicePaths:
         """Offsets open/closed curves by a distance using shapely. Handles optional rotation."""
         p = self
         if rotation and any(rotation):
@@ -770,7 +770,7 @@ def offset_geometry_to_paths(geom: BaseGeometry, z: float) -> list[np.ndarray]:
 def offset_curve_slice(
     slice_paths: list[np.ndarray],
     distance: float,
-    join_style: str = 'round'
+    join_style: Literal['round', 'mitre'] = 'round'
 ) -> tuple[list[np.ndarray], list[int]]:
     if not slice_paths:
         return [], []
@@ -909,7 +909,7 @@ def paths_to_shapely_polygon(paths: list[np.ndarray]) -> BaseGeometry:
     from shapely.geometry import Polygon
     from shapely.ops import unary_union
     
-    pc = pyclipper.Pyclipper()
+    pc = pyclipper.Pyclipper()  # pyright: ignore[reportAttributeAccessIssue]
     for p in paths:
         if len(p) < 3:
             continue
@@ -917,9 +917,9 @@ def paths_to_shapely_polygon(paths: list[np.ndarray]) -> BaseGeometry:
         if np.allclose(pts_2d[0], pts_2d[-1]):
             pts_2d = pts_2d[:-1]
         scaled = (pts_2d * SCALE).astype(np.int64).tolist()
-        pc.AddPath(scaled, pyclipper.PT_SUBJECT, True)
+        pc.AddPath(scaled, pyclipper.PT_SUBJECT, True) # pyright: ignore[reportAttributeAccessIssue]
         
-    tree = pc.Execute2(pyclipper.CT_UNION, pyclipper.PFT_EVENODD, pyclipper.PFT_EVENODD)
+    tree = pc.Execute2(pyclipper.CT_UNION, pyclipper.PFT_EVENODD, pyclipper.PFT_EVENODD) # pyright: ignore[reportAttributeAccessIssue]
     
     def polytree_to_shapely(node) -> list[Polygon]:
         polygons = []