Examples

#Groups Selector

h1, h2 {
    color: red;
}

#Chaining Selector

h3.section-heading {
    color: blue;
}

#Attribute Selector

div[attribute="SomeValue"] {
    background-color: red;
}

#First Child Selector

p:first-child {
    font-weight: bold;
}

#No Children Selector

.box:empty {
  background: lime;
  height: 80px;
  width: 80px;
}