border-top
Borders
Sets the top border only.
| How to write it | border-top: none; |
|---|---|
| Common values | none, 1px solid #ddd |
| Inherited | No — it stops at this element |
| Category | Borders |
How to read this
- An inherited property only needs writing once on the parent — every child picks it up. Most text properties work this way.
- A shorthand resets whatever you leave out. Writing background: red alone also wipes a background image you set earlier.
- When rules collide, the more specific selector wins; only when specificity ties does source order decide.
- Animate transform and opacity for smoothness. Changing width or top forces the layout to be recalculated.
Frequently asked questions
Q. What is the CSS border-top property?
Sets the top border only.
Q. How do you write border-top?
As border-top: none; Common values include none, 1px solid #ddd.
Q. Is border-top inherited?
No. It applies only where you write it, so each element needs its own declaration.
Q. What group does border-top belong to?
The borders group.