diff --git a/md_pdf/build/__init__.py b/md_pdf/build/__init__.py
index 11c8fb8..2c77bc5 100644
--- a/md_pdf/build/__init__.py
+++ b/md_pdf/build/__init__.py
@@ -1,4 +1,3 @@
-from md_pdf.consts import WORKING_DIR
 from md_pdf.build.md import read_files
 from md_pdf.build.pandoc import build_document, output_html
 from md_pdf.build.cover import render_cover
diff --git a/md_pdf/build/md.py b/md_pdf/build/md.py
index ea55c9f..49be8be 100644
--- a/md_pdf/build/md.py
+++ b/md_pdf/build/md.py
@@ -1,5 +1,6 @@
 import glob
 
+
 def get_files_content(filenames):
     for filename in filenames:
         with open(filename) as f:
diff --git a/md_pdf/build/pandoc.py b/md_pdf/build/pandoc.py
index 2853457..44b825f 100644
--- a/md_pdf/build/pandoc.py
+++ b/md_pdf/build/pandoc.py
@@ -6,6 +6,7 @@ from md_pdf.consts import PROJECT_DIR, CSL_DIR
 
 CSL_FILE = os.path.join(PROJECT_DIR, 'assets', 'harverd.csl')
 
+
 def fix_references_title(content):
     soup = BeautifulSoup(content, 'html.parser')
     reference_element = soup.find('div', class_='references')
@@ -33,7 +34,10 @@ def build_document(files_content, bibliography):
         ]
         filters.append('pandoc-citeproc')
 
-    html = pypandoc.convert_text(files_content, 'html', format='md',
+    html = pypandoc.convert_text(
+        files_content,
+        'html',
+        format='md',
         extra_args=args,
         filters=filters
     )
diff --git a/md_pdf/config/validate.py b/md_pdf/config/validate.py
index 8660401..0b97d6b 100644
--- a/md_pdf/config/validate.py
+++ b/md_pdf/config/validate.py
@@ -56,5 +56,3 @@ def validate_config(config):
         validate_bibliography
     ]:
         validator(config)
-
-