diff --git a/AppendBuffer.h b/AppendBuffer.h
index 3572d8d..231a79e 100644
--- a/AppendBuffer.h
+++ b/AppendBuffer.h
@@ -1,8 +1,7 @@
 /*
  * AppendBuffer.h - selector header to choose GapBuffer or PieceTable
  */
-#ifndef KTE_APPENDBUFFER_H
-#define KTE_APPENDBUFFER_H
+#pragma once
 
 #ifdef KTE_USE_PIECE_TABLE
 #include "PieceTable.h"
@@ -10,6 +9,4 @@ using AppendBuffer = PieceTable;
 #else
 #include "GapBuffer.h"
 using AppendBuffer = GapBuffer;
-#endif
-
-#endif // KTE_APPENDBUFFER_H
+#endif
\ No newline at end of file
diff --git a/Buffer.h b/Buffer.h
index faf941f..4e65236 100644
--- a/Buffer.h
+++ b/Buffer.h
@@ -1,8 +1,7 @@
 /*
  * Buffer.h - editor buffer representing an open document
  */
-#ifndef KTE_BUFFER_H
-#define KTE_BUFFER_H
+#pragma once
 
 #include <cstddef>
 #include <memory>
@@ -466,6 +465,4 @@ private:
 	bool syntax_enabled_   = true;
 	std::string filetype_;
 	std::unique_ptr<kte::HighlighterEngine> highlighter_;
-};
-
-#endif // KTE_BUFFER_H
+};
\ No newline at end of file
diff --git a/Command.h b/Command.h
index 0d8f912..93d55d9 100644
--- a/Command.h
+++ b/Command.h
@@ -1,8 +1,7 @@
 /*
  * Command.h - command model and registry for editor actions
  */
-#ifndef KTE_COMMAND_H
-#define KTE_COMMAND_H
+#pragma once
 
 #include <functional>
 #include <string>
@@ -155,6 +154,4 @@ void InstallDefaultCommands();
 // Returns true if the command executed successfully.
 bool Execute(Editor &ed, CommandId id, const std::string &arg = std::string(), int count = 0);
 
-bool Execute(Editor &ed, const std::string &name, const std::string &arg = std::string(), int count = 0);
-
-#endif // KTE_COMMAND_H
\ No newline at end of file
+bool Execute(Editor &ed, const std::string &name, const std::string &arg = std::string(), int count = 0);
\ No newline at end of file
diff --git a/Editor.h b/Editor.h
index 81d276f..d788c98 100644
--- a/Editor.h
+++ b/Editor.h
@@ -1,9 +1,7 @@
 /*
  * Editor.h - top-level editor state and buffer management
  */
-#ifndef KTE_EDITOR_H
-#define KTE_EDITOR_H
-
+#pragma once
 #include <cstddef>
 #include <ctime>
 #include <string>
@@ -561,6 +559,4 @@ public:
 private:
 	std::string replace_find_tmp_;
 	std::string replace_with_tmp_;
-};
-
-#endif // KTE_EDITOR_H
\ No newline at end of file
+};
\ No newline at end of file
diff --git a/Frontend.h b/Frontend.h
index 1ca1923..026f90c 100644
--- a/Frontend.h
+++ b/Frontend.h
@@ -1,9 +1,7 @@
 /*
  * Frontend.h - top-level container that couples Input + Renderer and runs the loop
  */
-#ifndef KTE_FRONTEND_H
-#define KTE_FRONTEND_H
-
+#pragma once
 
 class Editor;
 class InputHandler;
@@ -21,6 +19,4 @@ public:
 
 	// Shutdown/cleanup
 	virtual void Shutdown() = 0;
-};
-
-#endif // KTE_FRONTEND_H
+};
\ No newline at end of file
diff --git a/GUIConfig.h b/GUIConfig.h
index 49fb6fe..6590618 100644
--- a/GUIConfig.h
+++ b/GUIConfig.h
@@ -1,8 +1,7 @@
 /*
  * GUIConfig - loads simple GUI configuration from $HOME/.config/kte/kge.ini
  */
-#ifndef KTE_GUI_CONFIG_H
-#define KTE_GUI_CONFIG_H
+#pragma once
 
 #include <string>
 
@@ -31,6 +30,4 @@ public:
 
 	// Load from explicit path. Returns true if file existed and was parsed.
 	bool LoadFromFile(const std::string &path);
-};
-
-#endif // KTE_GUI_CONFIG_H
\ No newline at end of file
+};
\ No newline at end of file
diff --git a/GUIFrontend.h b/GUIFrontend.h
index c6c0ba6..10644a3 100644
--- a/GUIFrontend.h
+++ b/GUIFrontend.h
@@ -1,9 +1,7 @@
 /*
  * GUIFrontend - couples GUIInputHandler + GUIRenderer and owns SDL2/ImGui lifecycle
  */
-#ifndef KTE_GUI_FRONTEND_H
-#define KTE_GUI_FRONTEND_H
-
+#pragma once
 #include "Frontend.h"
 #include "GUIConfig.h"
 #include "GUIInputHandler.h"
@@ -35,6 +33,4 @@ private:
 	SDL_GLContext gl_ctx_ = nullptr;
 	int width_            = 1280;
 	int height_           = 800;
-};
-
-#endif // KTE_GUI_FRONTEND_H
\ No newline at end of file
+};
\ No newline at end of file
diff --git a/GUIInputHandler.h b/GUIInputHandler.h
index 4bbece5..da8d5fb 100644
--- a/GUIInputHandler.h
+++ b/GUIInputHandler.h
@@ -1,9 +1,7 @@
 /*
  * GUIInputHandler - ImGui/SDL2-based input mapping for GUI mode
  */
-#ifndef KTE_GUI_INPUT_HANDLER_H
-#define KTE_GUI_INPUT_HANDLER_H
-
+#pragma once
 #include <mutex>
 #include <queue>
 
@@ -41,6 +39,4 @@ private:
 	bool uarg_had_digits_ = false; // whether any digits were supplied
 	int uarg_value_       = 0; // current absolute value (>=0)
 	std::string uarg_text_; // raw digits/minus typed for status display
-};
-
-#endif // KTE_GUI_INPUT_HANDLER_H
+};
\ No newline at end of file
diff --git a/GUIRenderer.h b/GUIRenderer.h
index 7a5a75c..b83a773 100644
--- a/GUIRenderer.h
+++ b/GUIRenderer.h
@@ -1,9 +1,7 @@
 /*
  * GUIRenderer - ImGui-based renderer for GUI mode
  */
-#ifndef KTE_GUI_RENDERER_H
-#define KTE_GUI_RENDERER_H
-
+#pragma once
 #include "Renderer.h"
 
 class GUIRenderer final : public Renderer {
@@ -13,6 +11,4 @@ public:
 	~GUIRenderer() override = default;
 
 	void Draw(Editor &ed) override;
-};
-
-#endif // KTE_GUI_RENDERER_H
+};
\ No newline at end of file
diff --git a/GapBuffer.h b/GapBuffer.h
index 6cf5ab8..c8f7630 100644
--- a/GapBuffer.h
+++ b/GapBuffer.h
@@ -1,9 +1,7 @@
 /*
  * GapBuffer.h - C++ replacement for abuf append/prepend buffer utilities
  */
-#ifndef KTE_GAPBUFFER_H
-#define KTE_GAPBUFFER_H
-
+#pragma once
 #include <cstddef>
 
 
@@ -75,6 +73,4 @@ private:
 	char *buffer_         = nullptr;
 	std::size_t size_     = 0; // number of valid bytes (excluding terminator)
 	std::size_t capacity_ = 0; // capacity of buffer_ excluding space for terminator
-};
-
-#endif // KTE_GAPBUFFER_H
+};
\ No newline at end of file
diff --git a/HelpText.h b/HelpText.h
index 1e7f922..31502ff 100644
--- a/HelpText.h
+++ b/HelpText.h
@@ -1,9 +1,7 @@
 /*
  * HelpText.h - embedded/customizable help content
  */
-#ifndef KTE_HELPTEXT_H
-#define KTE_HELPTEXT_H
-
+#pragma once
 #include <string>
 
 class HelpText {
@@ -12,6 +10,4 @@ public:
 	// Project maintainers can customize the returned string below
 	// (in HelpText.cc) without touching the help command logic.
 	static std::string Text();
-};
-
-#endif // KTE_HELPTEXT_H
+};
\ No newline at end of file
diff --git a/InputHandler.h b/InputHandler.h
index fe4387b..6bfb50e 100644
--- a/InputHandler.h
+++ b/InputHandler.h
@@ -1,9 +1,7 @@
 /*
  * InputHandler.h - input abstraction and mapping to commands
  */
-#ifndef KTE_INPUT_HANDLER_H
-#define KTE_INPUT_HANDLER_H
-
+#pragma once
 #include <string>
 
 #include "Command.h"
@@ -24,6 +22,4 @@ public:
 	// Poll for input and translate it to a command. Non-blocking.
 	// Returns true if a command is available in 'out'. Returns false if no input.
 	virtual bool Poll(MappedInput &out) = 0;
-};
-
-#endif // KTE_INPUT_HANDLER_H
+};
\ No newline at end of file
diff --git a/KKeymap.h b/KKeymap.h
index 62b86ef..e5645db 100644
--- a/KKeymap.h
+++ b/KKeymap.h
@@ -1,9 +1,7 @@
 /*
  * KKeymap.h - mapping for k-command (C-k prefix) keys to CommandId
  */
-#ifndef KTE_KKEYMAP_H
-#define KTE_KKEYMAP_H
-
+#pragma once
 #include "Command.h"
 
 
@@ -29,6 +27,4 @@ KLowerAscii(const int key)
 	if (key >= 'A' && key <= 'Z')
 		return key + ('a' - 'A');
 	return key;
-}
-
-#endif // KTE_KKEYMAP_H
+}
\ No newline at end of file
diff --git a/OptimizedSearch.h b/OptimizedSearch.h
index 3893491..c4f0976 100644
--- a/OptimizedSearch.h
+++ b/OptimizedSearch.h
@@ -1,7 +1,5 @@
 // OptimizedSearch.h - Boyer–Moore (bad character) based substring search
-#ifndef KTE_OPTIMIZED_SEARCH_H
-#define KTE_OPTIMIZED_SEARCH_H
-
+#pragma once
 #include <array>
 #include <cstddef>
 #include <string>
@@ -22,6 +20,4 @@ private:
 	std::string last_pat_;
 
 	void build_bad_char(const std::string &pattern);
-};
-
-#endif // KTE_OPTIMIZED_SEARCH_H
\ No newline at end of file
+};
\ No newline at end of file
diff --git a/PieceTable.h b/PieceTable.h
index b110485..07022d4 100644
--- a/PieceTable.h
+++ b/PieceTable.h
@@ -1,9 +1,7 @@
 /*
  * PieceTable.h - Alternative to GapBuffer using a piece table representation
  */
-#ifndef KTE_PIECETABLE_H
-#define KTE_PIECETABLE_H
-
+#pragma once
 #include <cstddef>
 #include <string>
 #include <vector>
@@ -93,6 +91,4 @@ private:
 	mutable std::string materialized_;
 	mutable bool dirty_     = true;
 	std::size_t total_size_ = 0;
-};
-
-#endif // KTE_PIECETABLE_H
+};
\ No newline at end of file
diff --git a/Renderer.h b/Renderer.h
index f5371ed..cf20156 100644
--- a/Renderer.h
+++ b/Renderer.h
@@ -1,9 +1,7 @@
 /*
  * Renderer.h - rendering abstraction
  */
-#ifndef KTE_RENDERER_H
-#define KTE_RENDERER_H
-
+#pragma once
 
 class Editor;
 
@@ -12,6 +10,4 @@ public:
 	virtual ~Renderer() = default;
 
 	virtual void Draw(Editor &ed) = 0;
-};
-
-#endif // KTE_RENDERER_H
+};
\ No newline at end of file
diff --git a/TerminalFrontend.h b/TerminalFrontend.h
index 81538ea..4f8b837 100644
--- a/TerminalFrontend.h
+++ b/TerminalFrontend.h
@@ -1,9 +1,7 @@
 /*
  * TerminalFrontend - couples TerminalInputHandler + TerminalRenderer and owns ncurses lifecycle
  */
-#ifndef KTE_TERMINAL_FRONTEND_H
-#define KTE_TERMINAL_FRONTEND_H
-
+#pragma once
 #include <termios.h>
 
 #include "Frontend.h"
@@ -31,6 +29,4 @@ private:
 	// Saved terminal attributes to restore on shutdown
 	bool have_orig_tio_ = false;
 	struct termios orig_tio_{};
-};
-
-#endif // KTE_TERMINAL_FRONTEND_H
+};
\ No newline at end of file
diff --git a/TerminalInputHandler.h b/TerminalInputHandler.h
index 22e1113..bbc5096 100644
--- a/TerminalInputHandler.h
+++ b/TerminalInputHandler.h
@@ -1,9 +1,7 @@
 /*
  * TerminalInputHandler - ncurses-based input handling for terminal mode
  */
-#ifndef KTE_TERMINAL_INPUT_HANDLER_H
-#define KTE_TERMINAL_INPUT_HANDLER_H
-
+#pragma once
 #include "InputHandler.h"
 
 
@@ -30,6 +28,4 @@ private:
 	bool uarg_had_digits_ = false; // whether any digits were supplied
 	int uarg_value_       = 0; // current absolute value (>=0)
 	std::string uarg_text_; // raw digits/minus typed for status display
-};
-
-#endif // KTE_TERMINAL_INPUT_HANDLER_H
+};
\ No newline at end of file
diff --git a/TerminalRenderer.h b/TerminalRenderer.h
index bb34d60..85b1403 100644
--- a/TerminalRenderer.h
+++ b/TerminalRenderer.h
@@ -1,9 +1,7 @@
 /*
  * TerminalRenderer - ncurses-based renderer for terminal mode
  */
-#ifndef KTE_TERMINAL_RENDERER_H
-#define KTE_TERMINAL_RENDERER_H
-
+#pragma once
 #include "Renderer.h"
 
 
@@ -14,6 +12,4 @@ public:
 	~TerminalRenderer() override;
 
 	void Draw(Editor &ed) override;
-};
-
-#endif // KTE_TERMINAL_RENDERER_H
+};
\ No newline at end of file
diff --git a/TestFrontend.h b/TestFrontend.h
index e87e610..7adc0e4 100644
--- a/TestFrontend.h
+++ b/TestFrontend.h
@@ -1,9 +1,7 @@
 /*
  * TestFrontend.h - headless frontend for testing with programmable input
  */
-#ifndef KTE_TEST_FRONTEND_H
-#define KTE_TEST_FRONTEND_H
-
+#pragma once
 #include "Frontend.h"
 #include "TestInputHandler.h"
 #include "TestRenderer.h"
@@ -36,6 +34,4 @@ public:
 private:
 	TestInputHandler input_{};
 	TestRenderer renderer_{};
-};
-
-#endif // KTE_TEST_FRONTEND_H
+};
\ No newline at end of file
diff --git a/TestInputHandler.h b/TestInputHandler.h
index 66d47d5..793b866 100644
--- a/TestInputHandler.h
+++ b/TestInputHandler.h
@@ -1,9 +1,7 @@
 /*
  * TestInputHandler.h - programmable input handler for testing
  */
-#ifndef KTE_TEST_INPUT_HANDLER_H
-#define KTE_TEST_INPUT_HANDLER_H
-
+#pragma once
 #include <queue>
 
 #include "InputHandler.h"
@@ -29,6 +27,4 @@ public:
 
 private:
 	std::queue<MappedInput> queue_;
-};
-
-#endif // KTE_TEST_INPUT_HANDLER_H
+};
\ No newline at end of file
diff --git a/TestRenderer.h b/TestRenderer.h
index 8d4753a..dc04e8e 100644
--- a/TestRenderer.h
+++ b/TestRenderer.h
@@ -1,9 +1,7 @@
 /*
  * TestRenderer.h - minimal renderer for testing (no actual display)
  */
-#ifndef KTE_TEST_RENDERER_H
-#define KTE_TEST_RENDERER_H
-
+#pragma once
 #include <cstddef>
 
 #include "Renderer.h"
@@ -31,6 +29,4 @@ public:
 
 private:
 	std::size_t draw_count_ = 0;
-};
-
-#endif // KTE_TEST_RENDERER_H
+};
\ No newline at end of file
diff --git a/UndoNode.h b/UndoNode.h
index d098a67..d870214 100644
--- a/UndoNode.h
+++ b/UndoNode.h
@@ -1,6 +1,4 @@
-#ifndef KTE_UNDONODE_H
-#define KTE_UNDONODE_H
-
+#pragma once
 #include <cstdint>
 #include <string>
 
@@ -20,7 +18,4 @@ struct UndoNode {
 	std::string text;
 	UndoNode *child = nullptr; // next in current timeline
 	UndoNode *next  = nullptr; // redo branch
-};
-
-
-#endif // KTE_UNDONODE_H
+};
\ No newline at end of file
diff --git a/UndoNodePool.h b/UndoNodePool.h
index f6409d1..7204825 100644
--- a/UndoNodePool.h
+++ b/UndoNodePool.h
@@ -1,6 +1,4 @@
-#ifndef KTE_UNDONODEPOOL_H
-#define KTE_UNDONODEPOOL_H
-
+#pragma once
 #include <stack>
 #include <vector>
 #include <memory>
@@ -60,6 +58,4 @@ private:
 	std::size_t block_size_;
 	std::vector<std::unique_ptr<UndoNode[]> > blocks_;
 	std::stack<UndoNode *> available_;
-};
-
-#endif // KTE_UNDONODEPOOL_H
\ No newline at end of file
+};
\ No newline at end of file
diff --git a/UndoSystem.h b/UndoSystem.h
index 979e272..e8e36fd 100644
--- a/UndoSystem.h
+++ b/UndoSystem.h
@@ -1,6 +1,4 @@
-#ifndef KTE_UNDOSYSTEM_H
-#define KTE_UNDOSYSTEM_H
-
+#pragma once
 #include <string_view>
 #include <cstddef>
 #include <cstdint>
@@ -54,6 +52,4 @@ private:
 	UndoTree &tree_;
 	// Internal hint for Delete batching: whether next Append() should prepend
 	bool pending_prepend_ = false;
-};
-
-#endif // KTE_UNDOSYSTEM_H
+};
\ No newline at end of file
diff --git a/UndoTree.h b/UndoTree.h
index 4be268b..141b8f6 100644
--- a/UndoTree.h
+++ b/UndoTree.h
@@ -1,6 +1,4 @@
-#ifndef KTE_UNDOTREE_H
-#define KTE_UNDOTREE_H
-
+#pragma once
 #include "UndoNode.h"
 
 
@@ -9,7 +7,4 @@ struct UndoTree {
 	UndoNode *current = nullptr; // current state of buffer
 	UndoNode *saved   = nullptr; // points to node matching last save (for dirty flag)
 	UndoNode *pending = nullptr; // in-progress batch (detached)
-};
-
-
-#endif // KTE_UNDOTREE_H
+};
\ No newline at end of file
diff --git a/fonts/Font.h b/fonts/Font.h
index 15925e0..934fe2a 100644
--- a/fonts/Font.h
+++ b/fonts/Font.h
@@ -12,7 +12,7 @@ inline const unsigned int *DefaultFontData = BrassMonoCode::DefaultFontBoldCompr
 
 class Font {
 public:
-	Font(std::string name, unsigned int *data, const unsigned int size)
+	Font(std::string name, const unsigned int *data, const unsigned int size)
 		: name_(std::move(name)),
 		  data_(data),
 		  size_(size) {}
@@ -28,7 +28,7 @@ public:
 
 private:
 	std::string name_;
-	unsigned int *data_{nullptr};
+	const unsigned int *data_{nullptr};
 	unsigned int size_{0};
 };
 }
\ No newline at end of file
diff --git a/fonts/FontRegistry.cc b/fonts/FontRegistry.cc
index 5167658..018024d 100644
--- a/fonts/FontRegistry.cc
+++ b/fonts/FontRegistry.cc
@@ -7,87 +7,87 @@ InstallDefaultFonts()
 {
 	FontRegistry::Instance().Register(std::make_unique<Font>(
 		"default",
-		const_cast<unsigned int *>(BrassMono::DefaultFontBoldCompressedData),
+		BrassMono::DefaultFontBoldCompressedData,
 		BrassMono::DefaultFontBoldCompressedSize
 	));
 	FontRegistry::Instance().Register(std::make_unique<Font>(
 		"b612",
-		const_cast<unsigned int *>(B612Mono::DefaultFontRegularCompressedData),
+		B612Mono::DefaultFontRegularCompressedData,
 		B612Mono::DefaultFontRegularCompressedSize
 	));
 	FontRegistry::Instance().Register(std::make_unique<Font>(
 		"brassmono",
-		const_cast<unsigned int *>(BrassMono::DefaultFontBoldCompressedData),
+		BrassMono::DefaultFontBoldCompressedData,
 		BrassMono::DefaultFontBoldCompressedSize
 	));
 	FontRegistry::Instance().Register(std::make_unique<Font>(
 		"brassmonocode",
-		const_cast<unsigned int *>(BrassMonoCode::DefaultFontBoldCompressedData),
+		BrassMonoCode::DefaultFontBoldCompressedData,
 		BrassMonoCode::DefaultFontBoldCompressedSize
 	));
 	FontRegistry::Instance().Register(std::make_unique<Font>(
 		"fira",
-		const_cast<unsigned int *>(FiraCode::DefaultFontRegularCompressedData),
+		FiraCode::DefaultFontRegularCompressedData,
 		FiraCode::DefaultFontRegularCompressedSize
 	));
 	FontRegistry::Instance().Register(std::make_unique<Font>(
 		"go",
-		const_cast<unsigned int *>(Go::DefaultFontRegularCompressedData),
+		Go::DefaultFontRegularCompressedData,
 		Go::DefaultFontRegularCompressedSize
 	));
 	FontRegistry::Instance().Register(std::make_unique<Font>(
 		"ibm",
-		const_cast<unsigned int *>(IBMPlexMono::DefaultFontRegularCompressedData),
+		IBMPlexMono::DefaultFontRegularCompressedData,
 		IBMPlexMono::DefaultFontRegularCompressedSize
 	));
 	FontRegistry::Instance().Register(std::make_unique<Font>(
 		"idealist",
-		const_cast<unsigned int *>(Idealist::DefaultFontRegularCompressedData),
+		Idealist::DefaultFontRegularCompressedData,
 		Idealist::DefaultFontRegularCompressedSize
 	));
 	FontRegistry::Instance().Register(std::make_unique<Font>(
 		"inconsolata",
-		const_cast<unsigned int *>(Inconsolata::DefaultFontRegularCompressedData),
+		Inconsolata::DefaultFontRegularCompressedData,
 		Inconsolata::DefaultFontRegularCompressedSize
 	));
 	FontRegistry::Instance().Register(std::make_unique<Font>(
 		"inconsolataex",
-		const_cast<unsigned int *>(InconsolataExpanded::DefaultFontRegularCompressedData),
+		InconsolataExpanded::DefaultFontRegularCompressedData,
 		InconsolataExpanded::DefaultFontRegularCompressedSize
 	));
 	FontRegistry::Instance().Register(std::make_unique<Font>(
 		"iosevka",
-		const_cast<unsigned int *>(Iosoveka::DefaultFontRegularCompressedData),
+		Iosoveka::DefaultFontRegularCompressedData,
 		Iosoveka::DefaultFontRegularCompressedSize
 	));
 	FontRegistry::Instance().Register(std::make_unique<Font>(
 		"iosevkaex",
-		const_cast<unsigned int *>(IosevkaExtended::DefaultFontRegularCompressedData),
+		IosevkaExtended::DefaultFontRegularCompressedData,
 		IosevkaExtended::DefaultFontRegularCompressedSize
 	));
 	FontRegistry::Instance().Register(std::make_unique<Font>(
 		"sharetech",
-		const_cast<unsigned int *>(ShareTech::DefaultFontRegularCompressedData),
+		ShareTech::DefaultFontRegularCompressedData,
 		ShareTech::DefaultFontRegularCompressedSize
 	));
 	FontRegistry::Instance().Register(std::make_unique<Font>(
 		"space",
-		const_cast<unsigned int *>(SpaceMono::DefaultFontRegularCompressedData),
+		SpaceMono::DefaultFontRegularCompressedData,
 		SpaceMono::DefaultFontRegularCompressedSize
 	));
 	FontRegistry::Instance().Register(std::make_unique<Font>(
 		"syne",
-		const_cast<unsigned int *>(Syne::DefaultFontRegularCompressedData),
+		Syne::DefaultFontRegularCompressedData,
 		Syne::DefaultFontRegularCompressedSize
 	));
 	FontRegistry::Instance().Register(std::make_unique<Font>(
 		"triplicate",
-		const_cast<unsigned int *>(Triplicate::DefaultFontRegularCompressedData),
+		Triplicate::DefaultFontRegularCompressedData,
 		Triplicate::DefaultFontRegularCompressedSize
 	));
 	FontRegistry::Instance().Register(std::make_unique<Font>(
 		"unispace",
-		const_cast<unsigned int *>(Unispace::DefaultFontRegularCompressedData),
+		Unispace::DefaultFontRegularCompressedData,
 		Unispace::DefaultFontRegularCompressedSize
 	));
 }
diff --git a/main.cc b/main.cc
index 561dc2d..fee3bed 100644
--- a/main.cc
+++ b/main.cc
@@ -1,7 +1,10 @@
 #include <cctype>
+#include <cerrno>
 #include <cstdio>
+#include <cstring>
 #include <getopt.h>
 #include <iostream>
+#include <limits>
 #include <memory>
 #include <signal.h>
 #include <string>
@@ -41,10 +44,10 @@ main(int argc, const char *argv[])
 	Editor editor;
 
 	// CLI parsing using getopt_long
-	bool req_gui      = false;
-	bool req_term     = false;
-	bool show_help    = false;
-	bool show_version = false;
+	bool req_gui                   = false;
+	[[maybe_unused]] bool req_term = false;
+	bool show_help                 = false;
+	bool show_version              = false;
 
 	static struct option long_opts[] = {
 		{"gui", no_argument, nullptr, 'g'},
@@ -86,10 +89,6 @@ main(int argc, const char *argv[])
 		return 0;
 	}
 
-#if !defined(KTE_BUILD_GUI)
-	(void) req_term; // suppress unused warning when GUI is not compiled in
-#endif
-
 	// Determine frontend
 #if !defined(KTE_BUILD_GUI)
 	if (req_gui) {
@@ -104,11 +103,13 @@ main(int argc, const char *argv[])
 	} else if (req_term) {
 		use_gui = false;
 	} else {
-		// Default depends on build target: kge defaults to GUI, kte to terminal
+
+
+	// Default depends on build target: kge defaults to GUI, kte to terminal
 #if defined(KTE_DEFAULT_GUI)
-		use_gui = true;
+	use_gui = true;
 #else
-		use_gui = false;
+	use_gui = false;
 #endif
 	}
 #endif
@@ -134,7 +135,13 @@ main(int argc, const char *argv[])
 						// Clamp to >=1 later; 0 disables.
 						try {
 							unsigned long v = std::stoul(p);
-							pending_line    = static_cast<std::size_t>(v);
+							if (v > std::numeric_limits<std::size_t>::max()) {
+								std::cerr <<
+									"kte: Warning: Line number too large, ignoring\n";
+								pending_line = 0;
+							} else {
+								pending_line = static_cast<std::size_t>(v);
+							}
 						} catch (...) {
 							// Ignore malformed huge numbers
 							pending_line = 0;
@@ -193,8 +200,15 @@ main(int argc, const char *argv[])
 #if defined(KTE_BUILD_GUI) && defined(__APPLE__)
 	if (use_gui) {
 		/* likely using the .app, so need to cd */
-		if (chdir(getenv("HOME")) != 0) {
-			std::cerr << "kge.app: failed to chdir to HOME" << std::endl;
+		const char *home = getenv("HOME");
+		if (!home) {
+			std::cerr << "kge.app: HOME environment variable not set" << std::endl;
+			return 1;
+		}
+		if (chdir(home) != 0) {
+			std::cerr << "kge.app: failed to chdir to " << home << ": "
+				<< std::strerror(errno) << std::endl;
+			return 1;
 		}
 	}
 #endif
@@ -212,4 +226,4 @@ main(int argc, const char *argv[])
 	fe->Shutdown();
 
 	return 0;
-}
+}
\ No newline at end of file