dompdf supports the following CSS selector syntaxes. dompdf also supports elements with multiple class attributes (e.g. <p class="red bold">foo</p> matches p.red and p.bold).

Note that the CSS selectors are case sensitive in dompdf (e.g. .foo will not match <div class="FOO">bar</div>)

Selector	Supported	Version Added	Notes
*	yes
E	yes
E F	yes
E > F	yes
E.class	yes
E#myid	yes
E:root	yes	2.0.2
E:first-child	yes
E:last-child	yes	0.6.0
E:only-child	yes	2.0.2
E:first-of-type	partial	0.6.0
E:last-of-type	partial	0.6.0
E:only-of-type	partial	2.0.2
E:nth-child	yes	0.6.0
E:nth-last-child	yes	0.6.0	Parsed as nth-child until 0.8.0
E:nth-of-type	partial	0.6.0
E:nth-last-of-type	partial	0.6.0	Parsed as nth-of-type until 0.8.0
E:empty	yes
E:link	yes
E:any-link	yes	2.0.2
E:visited	N/A
E:active	N/A
E:hover	N/A
E:focus	N/A
E:lang(c)	no
E + F	yes		Behaved as E ~ F until 1.1.0
E ~ F	yes	1.1.0
E[foo]	yes
E[foo="warning"]	yes
E[foo~="warning"]	yes
E[foo$="warning"]	yes	0.6.0
E[foo^="warning"]	yes	0.6.0
E[foo*="warning"]	yes	0.6.0
E[lang|="en"]	yes

Page Selectors	Supported	Version Added	Notes
@page	yes
@page :left	yes	0.6.0	only margins are applied
@page :right	yes	0.6.0	only margins are applied
@page :odd	yes	0.6.0	only margins are applied
@page :even	yes	0.6.0	only margins are applied
@page :first	yes	0.6.0	only margins are applied

Property	Supported	Version Added	Notes
E::first-line	no
E::first-letter	no
E::before	yes		Only on block and inline elements
E::after	yes		Only on block and inline elements

dompdf supports the majority of CSS 2.1 properties and some CSS 3 properties. See the following table for details on which properties are supported.

Property	Supported	Version Added	Notes
background-attachment	N/A
background-color	yes
background-image	yes
background-position	yes
background-repeat	yes
background-size	yes	0.8.6
background	yes		Supports setting background-position and background-size since 1.2.0
border-collapse	yes
border-color	yes
border-radius	yes	0.6.0	Supported on inline elements since 2.0.0. Only supports single radius value per corner
border-spacing	yes
border-style	yes
border-top	yes
border-top-color	yes
border-top-style	yes
border-top-width	yes
border-width	yes
border	yes
bottom	yes		Supported for relative positioning since 1.1.0
box-shadow	no
box-sizing	no
caption-side	no		Caption elements are moved before the table, as block elements
clear	partial	0.6.0	In 0.6.x DOMPDF_ENABLE_CSS_FLOAT must be true
clip	no
color	yes
content	yes
counter-increment	yes
counter-reset	yes		Multiple counters supported with 1.2.0
cursor	N/A
direction	no
display	partial		Display type run-in is not supported
empty-cells	yes	0.6.0
float	partial	0.6.0	In 0.6.x DOMPDF_ENABLE_CSS_FLOAT must be true
font-family	yes
font-size	yes
font-stretch	no
font-style	yes
font-variant	no
font-weight	yes		Numeric font weights supported since 0.8.4. bolder and lighter keywords supported since 3.0.0
font	yes
height	yes
inset	yes	2.0.0
left	yes
letter-spacing	yes		Not supported when using the GD backend
line-height	yes
list-style-image	yes
list-style-position	yes
list-style-type	yes
list-style	yes
margin-right	yes
margin-top	yes
margin	yes
max-height	partial
max-width	yes		Supported on table cells since 1.1.0 (only absolute values)
min-height	partial
min-width	yes		Supported on table cells since 1.1.0 (only absolute values)
opacity	yes		Supports percentage values since 2.0.0. Not supported when using the GD backend
orphans	yes
outline-color	yes
outline-offset	yes	1.1.0
outline-style	yes
outline-width	yes
outline	yes		Takes border radius into account since 1.1.0. Supported on inline elements since 2.0.0
overflow	partial
overflow-wrap	yes	1.1.0
padding-top	yes
padding	yes
page-break-after	yes		Supported on table rows since 1.1.0. Not supported on table row groups
page-break-before	yes		Supported on table rows since 1.1.0. Not supported on table row groups
page-break-inside	yes		Not supported on table row groups
position	yes
quotes	yes
right	yes		Supported for relative positioning since 1.1.0
size	yes		for @page
src	partial		for @font-face
table-layout	yes	0.6.0
text-align	yes
text-decoration	yes
text-indent	yes
text-shadow	no
text-transform	yes
transform	yes		Except for 3D transformations
transform-origin	yes
top	yes
unicode-bidi	no
unicode-range	no		for @font-face
vertical-align	yes
visibility	yes
white-space	yes
widows	no
width	yes		auto support added in 0.7.1
word-break	no		Supports the deprecated break-word keyword only since 2.0.0
word-spacing	yes		Not supported when using the GD backend
word-wrap	yes	0.6.0	Alias of overflow-wrap since 1.1.0
z-index	yes
--*	yes	3.0.0	double-dash prefix custom properties syntax

Keyword	Supported	Version Added	Notes
initial	yes	1.2.0
inherit	yes
unset	yes	1.2.0
revert	no

Unit	Supported	Version Added	Notes
px	yes
pt	yes
%	yes
rem	yes	0.6.0
em	yes
cm	yes
mm	yes
ex	yes		Equals to em/2
in	yes
pc	yes
rad	yes	0.6.0	for 2D transforms
deg	yes	0.6.0	for 2D transforms
grad	yes	3.0.0	for 2D transforms
turn	yes	3.0.0	for 2D transforms

Color	Supported	Version Added	Notes
transparent	yes
currentcolor	yes	1.2.0
Basic color keywords	yes
Extended color keywords	yes
Numerical color values	yes
CMYK color values	yes	0.8.0
RGBA color values	yes	0.7.0	transparency was ignored prior to 0.7.1; space-separated syntax supported with 1.2.0
HSL color values	no
HSLA color values	no
CSS2 system colors	no

Function	Supported	Version Added	Notes
calc	yes	3.0.0

Function	Supported	Version Added	Notes
min	yes	3.0.0
max	yes	3.0.0
clamp	yes	3.0.0

Function	Supported	Version Added	Notes
round	partial	3.0.0	does not support rounding strategy or interval
mod	yes	3.0.0
rem	yes	3.0.0

Function	Supported	Version Added	Notes
sin	yes	3.0.0
cos	yes	3.0.0
tan	yes	3.0.0
asin	yes	3.0.0
acos	yes	3.0.0
atan	yes	3.0.0
atan2	yes	3.0.0

Function	Supported	Version Added	Notes
pow	yes	3.0.0
sqrt	yes	3.0.0
hypot	yes	3.0.0
log	yes	3.0.0
exp	yes	3.0.0

Function	Supported	Version Added	Notes
abs	yes	3.0.0
sign	yes	3.0.0

Function	Supported	Version Added	Notes
attr	partial		only parsed by the content property; does not support type or unit specification; does not support fallback value
url	partial		does not support SVG paths (element identifiers)
var	yes	3.0.0