PC vendor CSS prefix

[crcn]

This could provide additional functionality that isn't supported by HTML and CSS out of the box. For example:

Can be expressed with:

div {
  style {

    /* left right top bottom */
    --pc-constraints: 10px 10px 10px 10px
  }
}

Could be compiled to:

._class {
  left: 10px;
  top: 10px;
  position: absolute;
  width: calc(100% - 10px);
  height: calc(100% - 10px);
}

Considerations:

• Ensure taht