how to change variant options name

[xavierluca]

i have more then 5000 products on my webshop and i am building a new one but most of the product variant option names are diffrent i want them all to be "size" i added a custom css and it worked but when i tried saving it it would not let me please help me find a solution.

legend.form__label {

  position: relative;

  visibility: hidden;

}

legend.form__label::after {

  content: "Size";

  visibility: visible;

  position: absolute;

  top: 0;

  left: 0;

}

this code made it how i wanted but it wouldnt let me save it