A straightforward example of CSS inline styles can be explored using the Copy as HTML feature of the Arduino IDE. When editing a sketch, the code appears to the viewer as follows,

/**
 * PURPOSE:
 * AUTHOR:
 * DATE:
 * COMMENT: 
 */
int bits [] = {
  11,8,6,3};
int duration = 200;
int number = 0;
int limit = 16;

void setup(){
  for(int i=0; i<=3; i++)
    pinMode(bits[i], OUTPUT);
}

void loop(){
  for(int i=0; i<=3; i++)
     digitalWrite(bits[i],number & 1<<(3-i));
  delay(duration);
  // modular advance of the number 
  number = (number+1) % limit;
}

When the Copy as HTML feature is used to present the code in a web page, the HTML looks like this (the numbered lines have been included for reference purposes only),