change the font size on a label html

1.group {
2  margin-bottom: 20px;
3}
4.group label {
5  font-size: 10px;
6}
7.group2 label {
8  font-size: 4px;
9}

1<div class="group">
2  <label for="input1">First label</label>
3  <input type="text" name="input1">
4</div>
5<div class="group group2">
6  <label for="input2">Second label</label>
7  <input type="text" name="input2">
8</div>