CSS是一種優化web頁面設計的編程語言。它可以讓開發者們輕松地對各種元素，如文字、圖片、背景等進行樣式設置。以下是CSS中所有元素的列表：

/* 聲明 */
@charset
@font-face
@import
@media
@namespace
/* 選擇器 */
*    
[type = "text"]   
:first-letter   
:before    
:after    
:lang
:not   
:active   
:hover   
:focus   
:checked   
:empty   
:enabled   
:disabled   
:target   
:first-child   
:last-child   
:nth-child(n)   
:nth-last-child(n)   
:only-child   
:first-of-type   
:last-of-type   
:nth-of-type(n)   
:nth-last-of-type(n)   
:only-of-type   
:root   
:link   
:visited   
:default   
/* 值 */
!important   
initial   
inherit   
unset   
/* 屬性 */
align-content   
align-items   
align-self   
animation   
animation-name   
animation-duration   
animation-timing-function   
animation-delay   
animation-iteration-count   
animation-direction   
animation-fill-mode   
animation-play-state   
backface-visibility   
background   
background-attachment   
background-color   
background-image   
background-position   
background-repeat   
background-size   
border   
border-collapse   
border-color   
border-spacing   
border-style   
border-width   
bottom   
box-shadow   
box-sizing   
caption-side   
clear   
clip   
color   
column-count   
column-gap   
column-rule   
column-rule-color   
column-rule-style   
column-rule-width   
column-span   
column-width   
content   
counter-increment   
counter-reset   
cursor   
direction   
display   
empty-cells   
filter   
flex   
flex-basis   
flex-direction   
flex-flow   
flex-grow   
flex-shrink   
flex-wrap   
float   
font   
font-family   
font-size   
font-size-adjust   
font-stretch   
font-style   
font-variant   
font-weight   
height   
justify-content   
left   
letter-spacing   
line-height   
list-style   
list-style-image   
list-style-position   
list-style-type   
margin   
margin-bottom   
margin-left   
margin-right   
margin-top   
max-height   
max-width   
min-height   
min-width   
opacity   
order   
outline   
outline-color   
outline-offset   
outline-style   
outline-width   
overflow   
overflow-x   
overflow-y   
padding   
padding-bottom   
padding-left   
padding-right   
padding-top   
page-break-after   
page-break-before   
page-break-inside   
perspective   
perspective-origin   
position   
quotes   
resize   
right   
table-layout   
text-align   
text-align-last   
text-decoration   
text-indent   
text-justify   
text-transform   
top   
transform   
transform-origin   
transform-style   
transition   
transition-property   
transition-duration   
transition-timing-function   
transition-delay   
unicode-bidi   
vertical-align   
visibility   
white-space   
width   
word-break   
word-spacing   
word-wrap   
writing-mode   
z-index

以上是CSS的所有元素，其中有些極少使用，但是對提高開發效率、實現某些特效是非常有幫助的。