Quell is a free architect portfolio theme for Astro.
Other themes to consider
Craftline
Free theme for plumbers, electricians and other local trades: a scroll story with a CSS 3D house and a quote form that only says sent when it is.
Orrery
Free dark theme for consultants and small B2B firms: thirteen scroll effects with no animation library and a contact form that only says sent when it is.
Shoal
Free theme for real estate agents: full-screen photo hero, service tiles, area guides and a contact form that only says thank you once the message is really sent.
Contour
A free developer portfolio theme with a working contact form.
Lattice
A free developer portfolio theme.
Kavelle
A free interior design studio theme.