1. types: `<gradient>`: `linear-gradient()`: unitless `0` for <angle>

2. types: `<gradient>`: `repeating-linear-gradient()`: unitless `0` for <angle>

3. types: `<length>`: `dvb`, `dvh`, `dvi`, `dvmax`, `dvmin`, `dvw` units

4. types: `<length>`: `lvb`, `lvh`, `lvi`, `lvmax`, `lvmin`, `lvw` units

5. types: `<length>`: `svb`, `svh`, `svi`, `svmax`, `svmin`, `svw` units