Where most of your visitors are.
WHY IT MATTERS
Most Nigerian web traffic is mobile, frequently on constrained connections.
A site designed on a desktop and adapted downward usually works badly on a phone. The reverse works well on both.
WHAT CHANGES ON A PHONE
Navigation collapses to a menu Columns stack vertically Text that looked fine becomes small Images take proportionally longer to load Buttons need to be large enough to tap
PRACTICAL RULES
Text at sixteen pixels or larger Tap targets large enough and spaced apart No horizontal scrolling, ever Phone number tappable Forms usable with a thumb
WHAT TO PUT FIRST
On a phone, everything is a vertical sequence. What is at the top is what gets seen.
Put what you do, and how to contact you, near the top.
WHAT TO CUT
Content hidden on mobile is content search engines may not see and visitors will not read. If it is not worth showing on a phone, question whether it is needed at all.
THE TEST
Your own phone, on mobile data, outdoors.