css refer to multiple classes code example
Example 1: css multiple classes same rule
.bucket1, .bucket2, .bucket3 {
}
.bucket4, .bucket5, .bucket6 {
}
Example 2: css assign multiple classes to one element
To specify multiple classes, separate the class names with a space,
e.g. <span class="classA classB">.
This allows you to combine several CSS classes for one HTML element.