You are an expert Verilog hardware designer working on a complete FPGA or ASIC project. You are given the full source code of a Verilog project. One of the modules in the project is incomplete — its implementation is missing and marked with:

// >>> Module Implementation Begin

// <<< Module Implementation End

Your task is to complete the missing implementation so that the entire project functions correctly. You must infer what the missing module or logic is supposed to do by analyzing the rest of the codebase: module names, signal connections, instantiations, comments, and usage patterns.

Follow these rules:

1. Only generate Verilog code to go between the `// >>> Module Implementation Begin` and `// <<< Module Implementation End` comments.
2. Use Verilog-2001 syntax. Ensure the code is synthesizable.
3. Assume the goal is a working, integrated hardware design — your code must make the whole system function as intended.
4. Analyze the naming, I/O ports, and how the module is instantiated or used in other parts of the project.
5. Implement correct behavior based on design context. Do not guess randomly — reason it out.
6. Avoid vendor-specific features unless explicitly required.
7. Do not output comments, explanation, or anything outside the required code region unless explicitly asked.

Your output should contain **only the Verilog code** that fits inside the marked region.

/*
 * Copyright (c) 2024 Rebecca G. Bettencourt
 * SPDX-License-Identifier: Apache-2.0
 */

`default_nettype none

module tt_um_rebeccargb_styler (
    input  wire [7:0] ui_in,    // Dedicated inputs
    output wire [7:0] uo_out,   // Dedicated outputs
    input  wire [7:0] uio_in,   // IOs: Input path
    output wire [7:0] uio_out,  // IOs: Output path
    output wire [7:0] uio_oe,   // IOs: Enable path (active high: 0=input, 1=output)
    input  wire       ena,      // always 1 when the design is powered, so you can ignore it
    input  wire       clk,      // clock
    input  wire       rst_n     // reset_n - low to reset
);

  reg [3:0] scanlineIn;
  wire [3:0] scanlineOut;
  reg [7:0] ctrl;
  reg [15:0] bitmapIn;
  wire [15:0] bitmapOut;
  reg [24:0] attr;

  wire faintPhase = ui_in[3] & ~ctrl[7];
  wire blinkPhase = ui_in[4];
  wire cursorPhase = ctrl[7] ? ui_in[3] : ~ui_in[4];
  wire cursorEnable = ui_in[5] & ctrl[3];

  styler s(
    .scanlineIn(scanlineIn), .bitmapIn(bitmapIn),
    .xoffset(attr[0]), .xscale(attr[1]),
    .yoffset(attr[2]), .yscale(attr[3]),
    .xPreMirror(attr[4]), .xPostMirror(attr[5]),
    .yPreMirror(attr[6]), .yPostMirror(attr[7]),
    .bold(attr[8]), .faint(attr[9]), .italic(attr[10]), .reverseItalic(attr[11]),
    .blink(attr[12]), .alternate(attr[13]), .inverse(attr[14]), .hidden(attr[15]),
    .underline(attr[16]), .doubleUnderline(attr[17]), .dottedUnderline(attr[18]),
    .strikethru(attr[19]), .doubleStrikethru(attr[20]), .dottedStrikethru(attr[21]),
    .overline(attr[22]), .doubleOverline(attr[23]), .dottedOverline(attr[24]),
    .extraBold(ctrl[6]), .blinkEnable(ctrl[5]), .lineEnable(ctrl[4]),
    .cursorEnable(cursorEnable), .cursorBlink(ctrl[2]),
    .cursorTop(ctrl[1]), .cursorBottom(ctrl[0]),
    .faintPhase(faintPhase), .blinkPhase(blinkPhase), .cursorPhase(cursorPhase),
    .scanlineOut(scanlineOut), .bitmapOut(bitmapOut)
  );

  wire [7:0] a8 = (
    ui_in[1] ?
    (ui_in[0] ? {7'b0, attr[24]} : attr[23:16]) :
    (ui_in[0] ? attr[15:8] : attr[7:0])
  );

  wire [7:0] b8 = (
    ui_in[0] ? bitmapOut[15:8] : bitmapOut[7:0]
  );

  wire [7:0] f8 = (
    ui_in[2] ? a8 :
    ui_in[1] ? b8 :
    ui_in[0] ? ctrl :
    {4'b0, scanlineOut}
  );

  assign uo_out  = f8;
  assign uio_out = f8;
  assign uio_oe  = {8{~ui_in[6]}};

  task reset; begin
    scanlineIn <= 4'h0;
    ctrl <= 8'h3C;
    bitmapIn <= 16'h0000;
    attr <= 25'h0000000;
  end endtask

  task write; begin
    case (ui_in[2:0])
      0: scanlineIn <= uio_in[3:0];
      1: ctrl <= uio_in;
      2: bitmapIn[7:0] <= uio_in;
      3: bitmapIn[15:8] <= uio_in;
      4: attr[7:0] <= uio_in;
      5: attr[15:8] <= uio_in;
      6: attr[23:16] <= uio_in;
      7: attr[24] <= uio_in[0];
    endcase
  end endtask

  always @(posedge clk) begin
    if (~rst_n) reset;
    else if (~ui_in[7]) write;
  end

  // List all unused inputs to prevent warnings
  wire _unused = &{ena, clk, rst_n, 1'b0};

endmodule


module styler_linegen (
	input wire [3:0] scanlineIn,
	input wire yoffset,
	input wire yscale,
	input wire faint,
	input wire inverse,
	input wire underline,
	input wire strikethru,
	input wire overline,
	input wire doubleUnderline,
	input wire doubleStrikethru,
	input wire doubleOverline,
	input wire dottedUnderline,
	input wire dottedStrikethru,
	input wire dottedOverline,
	input wire faintPhase,
	input wire lineEnable,
	input wire cursorEnable,
	input wire cursorBlink,
	input wire cursorPhase,
	input wire cursorTop,
	input wire cursorBottom,
	input wire yPreMirror,
	input wire yPostMirror,
	output wire [3:0] bitmapScanline,
	output wire [3:0] effectScanline,
	output wire inverseOut,
	output wire faintOut,
	output wire faintPhaseOut,
	output wire solidLineOut
);

	wire [3:0] s0 = scanlineIn;
	wire cursor = cursorEnable & (cursorPhase | ~cursorBlink) & (
		(~(cursorTop | cursorBottom)) | (cursorTop & (s0 < 3)) | (cursorBottom & (s0 > 12))
	);

	wire [3:0] s1 = yPostMirror ? (s0 ^ 4'hF) : s0;
	wire [3:0] s2 = yscale ? {1'b0, s1[3:1]} : s1;
	wire [3:0] s3 = yoffset ? (s2 ^ 4'h8) : s2;

	wire sl0 = lineEnable & (underline | doubleUnderline | dottedUnderline) & (doubleUnderline ? underline ? (s3 == 15) : (s3 == 13 || s3 == 15) : (s3 == 13));
	wire sl1 = lineEnable & (strikethru | doubleStrikethru | dottedStrikethru) & (doubleStrikethru ? strikethru ? (s3 == 5 || s3 == 7 || s3 == 9) : (s3 == 6 || s3 == 8) : (s3 == 7));
	wire sl2 = lineEnable & (overline | doubleOverline | dottedOverline) & (doubleOverline ? overline ? (s3 == 2) : (s3 == 0 || s3 == 2) : (s3 == 0));
	wire dottedLine = (sl0 & dottedUnderline) | (sl1 & dottedStrikethru) | (sl2 & dottedOverline);
	wire solidLine = sl0 | sl1 | sl2;

	assign effectScanline = s3;
	assign bitmapScanline = yPreMirror ? (s3 ^ 4'hF) : s3;
	assign inverseOut = inverse ^ cursor;
	assign faintOut = faint | dottedLine;
	assign faintPhaseOut = faintPhase ^ s1[0];
	assign solidLineOut = solidLine;

endmodule


module styler_style (
	input wire [15:0] bitmapIn,
	input wire xoffset,
	input wire xscale,
	input wire bold,
	input wire extraBold,
	input wire italic,
	input wire reverse,
	input wire xPreMirror,
	input wire [3:0] scanline,
	output wire [15:0] bitmapOut
);

	wire [15:0] b0 = bitmapIn;
	wire [15:0] b1 = xPreMirror ? {
		b0[0], b0[1], b0[2], b0[3], b0[4], b0[5], b0[6], b0[7],
		b0[8], b0[9], b0[10], b0[11], b0[12], b0[13], b0[14], b0[15]
	} : b0;

	wire [15:0] b2 = (
		(italic & ~reverse) ? (
			(scanline < 4) ? {2'b00, b1[15:2]} :
			(scanline < 8) ? {1'b0, b1[15:1]} :
			(scanline < 12) ? b1[15:0] :
			{b1[14:0], 1'b0}
		) :
		(reverse & ~italic) ? (
			(scanline < 4) ? {b1[13:0], 2'b00} :
			(scanline < 8) ? {b1[14:0], 1'b0} :
			(scanline < 12) ? b1[15:0] :
			{1'b0, b1[15:1]}
		) :
		b1
	);

	wire [15:0] b3 = bold ? extraBold ? ({b2[14:0], 1'b0} | b2 | {1'b0, b2[15:1]}) : (b2 | {1'b0, b2[15:1]}) : b2;
	wire [15:0] b4 = xoffset ? {b3[7:0], b3[15:8]} : b3;
	wire [15:0] b5 = xscale ? {
		b4[15], b4[15], b4[14], b4[14], b4[13], b4[13], b4[12], b4[12],
		b4[11], b4[11], b4[10], b4[10], b4[9], b4[9], b4[8], b4[8]
	} : b4;

	assign bitmapOut = b5;

endmodule


module styler_invert (
	input wire [15:0] bitmapIn,
	input wire blink,
	input wire alternate,
	input wire inverse,
	input wire hidden,
	input wire blinkPhase,
	input wire blinkEnable,
	input wire faint,
	input wire faintPhase,
	input wire solidLine,
	input wire xPostMirror,
	output wire [15:0] bitmapOut
);
// >>> Module Implementation Begin

// <<< Module Implementation End
endmodule




module styler (
	input wire [3:0] scanlineIn,
	input wire [15:0] bitmapIn,
	input wire xoffset,
	input wire xscale,
	input wire yoffset,
	input wire yscale,
	input wire xPreMirror,
	input wire xPostMirror,
	input wire yPreMirror,
	input wire yPostMirror,
	input wire bold,
	input wire faint,
	input wire italic,
	input wire reverseItalic,
	input wire blink,
	input wire alternate,
	input wire inverse,
	input wire hidden,
	input wire underline,
	input wire doubleUnderline,
	input wire dottedUnderline,
	input wire strikethru,
	input wire doubleStrikethru,
	input wire dottedStrikethru,
	input wire overline,
	input wire doubleOverline,
	input wire dottedOverline,
	input wire extraBold,
	input wire blinkEnable,
	input wire lineEnable,
	input wire cursorEnable,
	input wire cursorBlink,
	input wire cursorTop,
	input wire cursorBottom,
	input wire faintPhase,
	input wire blinkPhase,
	input wire cursorPhase,
	output wire [3:0] scanlineOut,
	output wire [15:0] bitmapOut
);

	wire [3:0] scanlineInt;
	wire inverseInt;
	wire faintInt;
	wire faintPhaseInt;
	wire solidLineInt;
	wire [15:0] bitmapInt;

	styler_linegen lg(
		scanlineIn,
		yoffset,
		yscale,
		faint,
		inverse,
		underline,
		strikethru,
		overline,
		doubleUnderline,
		doubleStrikethru,
		doubleOverline,
		dottedUnderline,
		dottedStrikethru,
		dottedOverline,
		faintPhase,
		lineEnable,
		cursorEnable,
		cursorBlink,
		cursorPhase,
		cursorTop,
		cursorBottom,
		yPreMirror,
		yPostMirror,
		scanlineOut,
		scanlineInt,
		inverseInt,
		faintInt,
		faintPhaseInt,
		solidLineInt
	);

	styler_style sty(
		bitmapIn,
		xoffset,
		xscale,
		bold,
		extraBold,
		italic,
		reverseItalic,
		xPreMirror,
		scanlineInt,
		bitmapInt
	);

	styler_invert inv(
		bitmapInt,
		blink,
		alternate,
		inverseInt,
		hidden,
		blinkPhase,
		blinkEnable,
		faintInt,
		faintPhaseInt,
		solidLineInt,
		xPostMirror,
		bitmapOut
	);

endmodule


Reference solution:
rtl/generated.v: 
	wire [15:0] b0 = bitmapIn;
	wire [15:0] b1 = solidLine ? 16'hFFFF : b0;
	wire [15:0] b2 = faint ? (b1 & (faintPhase ? 16'h5555 : 16'hAAAA)) : b1;
	wire [15:0] b3 = hidden ? 16'h0000 : b2;
	wire [15:0] b4 = (blink & blinkPhase & blinkEnable) ? 16'h0000 : b3;
	wire [15:0] b5 = (alternate & (blinkPhase | ~blinkEnable)) ? (b4 ^ 16'hFFFF) : b4;
	wire [15:0] b6 = inverse ? (b5 ^ 16'hFFFF) : b5;

	wire [15:0] b7 = xPostMirror ? {
		b6[0], b6[1], b6[2], b6[3], b6[4], b6[5], b6[6], b6[7],
		b6[8], b6[9], b6[10], b6[11], b6[12], b6[13], b6[14], b6[15]
	} : b6;

	assign bitmapOut = b7;