🎨 Important CSS Properties

Property Usage Where Used Extra Notes
display Defines element type Layout block, inline, flex, grid
position Positioning element Layout static, relative, absolute, fixed
top / left / right / bottom Move positioned elements Layout Works with position
z-index Layer order Overlapping elements Higher = on top
width / height Set size All elements px, %, vw, vh
margin Outer spacing Layout Space outside element
padding Inner spacing Layout Space inside element
box-sizing Size calculation Layout border-box recommended
color Text color Text name, hex, rgb
font-size Text size Text px, em, rem
font-family Font style Text Fallback fonts
font-weight Text thickness Text normal, bold, 100–900
text-align Text alignment Text left, center, right
background-color Background color UI Any color format
background-image Background image UI url(), gradients
background-size Image size Background cover, contain
border Border around element UI width style color
border-radius Rounded corners UI px or %
box-shadow Shadow effect UI x y blur color
display: flex Flex layout Responsive design One-dimensional
justify-content Horizontal alignment Flexbox center, space-between
align-items Vertical alignment Flexbox center, stretch
transition Smooth change Hover effects time + property
transform Scale, rotate Animations scale(), rotate()
animation Keyframe animation Advanced effects Uses @keyframes
opacity Transparency UI 0 to 1
overflow Content overflow Containers hidden, scroll