CSS Change rem unit default value

/* This will change the value of 1 rem */  
html {  
  /* font-size: 10px; */ /* But this will cause problems with people who change browser's font size */  
  /* Percentage of user's browser font size setting */  
  font-size: 62.5%; /* 10px / 16px = 0.625 = 62.5% */  
}