pansies from seed
I started some pansies from seed in flats. I kept them in the dark for about 10 days. I got some long white stems with a couple of small green leaves at the end. They looked a little leggy, so I decided to turn the lights on them. I have the lights set for about 16 hours a day. The flats have domes over them. I am keeping the soil warm at about 85 degrees. Now the stems have all fallen. They look dead. The soil is damp so I know it isn't a lack of water. They seem to have started drooping when the lights went on. I need to know what to do to salvage these plants.
As soon as seeds germinate they need sunlight. The pale and leggy seedlings likely did not have the energy to keep going and the change to sunlight was too stressful.
There is also a condition called dampening off, this is a fungus that kills young seedlings.
The good news is you gained some experience and you can easily resow some seeds.
These links will help you.