Sunscreens

SPF 50 if you're outdoors a lot or treating pigmentation. Otherwise pick whichever texture you'll wear every day — that's the bigger factor.

Some do. Look for non-comedogenic gel or fluid textures rather than rich creams, and remove it properly at night — leftover sunscreen is a common cause of congestion blamed on the sunscreen itself.

If you sit near a window, yes. UVA passes through glass and it's the wavelength involved in pigmentation and ageing.

Mineral (zinc, titanium) is gentler and better for sensitive or reactive skin, but heavier and more likely to leave a cast. Chemical filters are lighter and more cosmetically elegant. Neither is unsafe.

Korean chemical formulas and the tinted options avoid it. If you have deeper skin, the tinted versions and the newer Korean fluids are the ones to look at first.