Seedling Stem leggy droopy..help!

My seedling has been slow but doing alright (8days after planting)

This morning, I have checked that the stem got leggy, pale and leaves were droopy..
The color was light greenish too..

So, I repot her more deeply and gave her 50ml of water
because she was almost falling down by blowing fan....

I don't think it's overwatering. surface and coco was quite dried out.
Is this could be a symptom of underwatering?
or is this a damping-off?..Any possible way to bring her back?

I have been running 24hrs light with no darkness..
Is this could be a reason?..

Please help..I am really depressed and worried..

Genetics: Hericules from Sannie's shop, Netherland (Indica)
Lights: 45W Flourescent 'white' x2 (Running 24/0)
RH: 60~70% (Humidifier inside tent)
Temp: 77~80 F (120mm PC Fan x3 blowing)
Medium: GH Coco Coir/Perlite (60/40)
Water PH: 5.9~6.1 (No nutes)

Just let it go for a day I was thinking at first a water issue but maybe it's to humid I just read something about humidity and plant problems maybe look into that

24/0 is not your problem.

in fact I don't really know if you have a problem yet.

your specs seem to be fine, so keep an eye on her,

if she keeps deteriorating, then shoot us a post.

but I would leave her for a day or two, with a decent watering schedule.

just MY opinion,

hope I can help a little.
Coma

The leggy I am guessing is just it turning toward the light. You want to rotate the plant if that is the case. All looks ok to me.