A simple way reset last margin in css

Fir example I have a To-Do list ul > li for short.

Between each li I have a margin-bottom.

.todo-item {
  margin-bottom: 1rem;
}

.todo-item:last-child {
  margin-bottom: 0;
}

But you can use this for it:

.todo-item:not(:last-child) {
  margin-bottom: 1rem;
}

:not has great Browsers support

Use and happy!