.Document { 
  background-color: silver; 
  color: gray; 
} 
.Document.-main { 
  padding: 30px; 
} 
.Document.-main > heading { 
  border-bottom: 1px solid gray; 
  background-color: silver; 
} 

.Document.-main > heading > h1 { 
  color: black; 
} 

.Cat { 
  color: black; 
} 

.\$car { 
  background-image: url('car.png'); 
}