Erroneous indents added when pasting

When I paste code that is already properly indented, extra indents are added, forcing the manual removal of indents in order to achieve consistent indentation for readability). For example, if I copy this:

  color: var(--color-primary);
  background: var(--color-bkgrd-highlight);
  border-left-color: var(--color-primary);

…when pasted it is now like this:

  color: var(--color-primary);
    background: var(--color-bkgrd-highlight);
    border-left-color: var(--color-primary);