Underlined items means it stands for something else. i.e. length=number.
W3Schools CSS Reference
ClassType AttributesExamples
font-familyfamily-name | generic-family-name Times | serif, Courier | monospace, sans-serif | Helvetica
font-stylenormal | italic | oblique
font-variantnormal | small-caps
font-weight normal|bold|bolder|lighter|100|200|300|400|500|600|700|800|900
font-sizeabsolute-size|relative-size|length|percent Absolute=xx-small,x-small,small, medium, large,x-large,xx-large.   relative=smaller,larger
font font-family [font-style font-variant font-weight font-size line-height]
colorcolor
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background-colorcolor | transparent
background-imageURL | none
background-attachmentscroll | fixed
background-position percent | length | [[left| center|right] [top|center| bottom]]
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textword-spacinglength | normal
textword-wrapnormal | break-word break-word allows long words to be broken.
textletter-spacinglength | normal
text-decoration Set color, style, line, and shadow in one call
text-decoration-colorcolor
text-decoration-stylesolid(default)|double|dotted|dashed|wavy determines the way the line (if any) is displayed.
text-decoration-linenone(default)|underline|overline| line-throughdetermines where a line (if any) is displayed.
text-decoration-shadow
textvertical-align percent | baseline | sub | super | top | text-top | middle | bottom | text-bottom
text-transform capitalize | uppercase | lowercase | none(default) convert all text in a block
text-align left | right | center | justify
text-indentlength | percent Used on the first line in a <P>
textline-height normal | length | percent | number
texttab-sizenumbernumber of spaces to substitute for a tab
text-justifyauto|inter-word|distribute|none|trim determines how to justify if text-align is set to justify.
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boxmargin-topauto | length | percent
boxmargin-rightauto | length | percent
boxmargin-bottomauto | length | percent
boxmargin-leftauto | length | percent
boxmarginmagin-top margin-right margin-bottom margin-left
boxpadding-toplength | percent
boxpadding-rightlength | percent
boxpadding-bottomlength | percent
boxpadding-leftlength | percent
boxpaddingpadding-top padding-right padding-bottom padding-left
boxborder-top-width length | thin | medium | thick
boxborder-right-width length | thin | medium | thick
boxborder-bottom-width length | thin | medium | thick
boxborder-left-width length | thin | medium | thick
boxborder-width border-top-width border-right-width border-bottom-width border-left-width specify each width using one call
boxborder-colorcolor
boxborder-style none|dotted|dashed|solid|double|groove|ridge|inset|outset
boxborder-top border-top-width border-style border-color add width, color, and style attributes to border-top
boxborder-right border-right-width border-style border-color add width, color, and style attributes to border-right
boxborder-bottom border-bottom-width border-style border-color add width, color, and style attributes to border-bottom
boxborder-left border-left-width border-style border-color add width, color, and style attributes to border-left
boxborderborder-width border-style border-color all borders at once with the same values
boxwidthauto | length | percent
boxheightauto | length | percent
boxfloatleft | right | none
boxclearnone | left | right | both
boxvisibilityhidden | visible | collapse collapse=hidden for most items
boxvertical-aligntop|text-top|middle|bottom|text-bottom|sub|super
boxmax-heightnone(default)|length|percent length=100px or 75%
boxmax-widthnone(default)|length|percent length=100px or 75%
boxmin-heightnone(default)|length|percent length=100px or 75%
boxmin-widthnone(default)|length|percent length=100px or 75%
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classdisplay block | inline | list-item | none
classwhite-spacenormal | pre | nowrap
classlist-style-type disc|circle|square|decimal|lower-roman|upper-roman|lower-alpha| upper-alpha|none
classlist-style-imageURL | none
classlist-style-positioninside | outside
classlist-style list-style-type list-style-image list-style-position
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tableborder-spacinglength
tableempty-cellsshow(default)|hide
tabletable-layoutauto(default)|fixed
tablecaption-sidetop(default)|bottom
tableborder-collapseseparate(default)|collapse
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list-styleset all list styles in one call
listcounter-increment complicated. Uses counter-reset to allow subsections.
listcounter-reset Uses counter-increment to allow subsections.
list-style-imagenone(default)|URL
list-style-positioninside|outside(default) determines where the marker will be placed.
list-style-type none(default)|disc|circle|decimal|square|many more see the w3schools site for the full list
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uiresizenone(default)|both|vertical|horizontal determines if an element can be resized by the user.
uicursormanysets the cursor shape.

Usage

In StylesheetIn Document
#menu {float: left; width: 10em; }<DIV id="menu">
p {text-indent: 2em; }<P>
td.r {text-align: right; }<TD class="r"
<P STYLE="font-size: 18pt"></P>

Use <LINK REF="stylesheet" TYPE="text/css" HREF="file.css"> to link the external stylesheet to the document.
Use <STYLE TYPE="text/css"> P {text-indent: 3em;} </STYLE> to create stylesheet codes in the HEAD section.