What should the font value of CSS be?

We have spent a lot of time learning HTML, CSS, JS in these four months, and we often use this property in CSS:

. Div1{border-left-width:1px;border-left-style:solid;border-left-color: #ddd;}. div2{padding-top:3px;padding-right:4px;padding-bottom:5px;padding-left:6px;}. div3{background-position:111px 222px;background-image:url (image.png); background-repeat:no-repeat; Background-color: #cfc;}

And we can merge them into this:

. div1{border-left:1px solid #ddd;}. div2{padding:3px 4px 5px 6px;}. div3{background:111px 222px URL (image.png) no-repeat #cfc;}

In the values of these properties, the order is indifferent, and the number is also variable, the middle can also omit some do not write, can also be a value for two properties, it seems normal, but there is a CSS property is a special case, that is, font.

Font:font-style¦¦font-variant¦¦font-weight¦¦font-size¦¦line-height¦¦font-family

Font Sets or retrieves the text attributes in an object. This property is a composite property. The default value is: normal normal normal medium normal "times New Roman". The first method of declaring a parameter must be arranged in the order shown above. Only one value is allowed per parameter. Ignores the default value of the standalone property whose arguments correspond to.

P {font:12px/14px Sans-serif}p {font:80% sans-serif}p {font:x-large/110% "New Century Schoolbook", serif}p {font : Bold Italic Large Palatino, serif}p {font:normal small-caps 120%/120% fantasy}p {font:oblique 12pt "Helvetica Nue" , serif; font-stretch:condensed}

And in addition to these sequential attributes, the size and family of the font are essential.

Summarize:

I don't know if I understand, I just follow my own understanding and look at some information, but if you do not set a value in the font, he will use the default value, and other properties will not have a value.

　　

　

What should the font value of CSS be?