Zend certified PHP/Magento developer

getting all categories and subcategories

I’m trying to get all categories and subcategories i want to select them dynamically where if i add in the subcategory another subcategory and whenever i add … , it will return them all but i dont want to return them all in the same function because when i want to style them i’m facing problems ,i added a image shows how i want to display them. maybe in Radiators subcategory there is another subcategory ….. so i want to get them all but in way that i can control with their style

Heating Solar
Boilers
Radiators
Floor Heating
….

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