Copy Codeselector {  
    property: value;  
}  

Element div, Class ., ID #
Pseudo-classes :hover, :nth-child()

Hierarchy: Inline > ID > Class > Element

Copy Code/* This is a comment */  

Copy Code.container {  
  display: flex;  
  justify-content: center;  
  align-items: center;  
  gap: 1rem;  
}  

Copy Code.grid {  
  display: grid;  
  grid-template-columns: repeat(3, 1fr);  
  grid-gap: 20px;  
}  

Copy Code@media (max-width: 768px) { ... }  

Copy Code@keyframes slide {  
  0% { transform: translateX(-100%); }  
  100% { transform: translateX(0); }  
}  

Copy Code:root {  
  --primary-color: #2196F3;  
}  
.element {  
  color: var(--primary-color);  
}