If someone accidentally scratched me with their nails, does this transmit hiv? superficial scratch without any blood?

No it should not under the circumstances described even if they are HIV positive.

HIV is transmitted through broken skin, open wounds, but mostly through mucosal membranes which is not what above scenario describes. A reliable site is cdc.gov in clarifying STD’s in general.

HIV is a blood to blood transmission. bodily fluids, semen and even breast milk. No blood on scratch or from a bloody nail, then no transmission of HIV.