9.22 Classroom Records

One, block element

Block-level element code!

#d1, #d2 {height:100px;width:100px;border:solid 2px #FF0000;d isplay:inline;
｝

< Div = "D1" ></ Div > < Div = "D2" ></ Div >

Block element Features:

1, displayed by default in the upper-left corner of the parent tag (body)

2, block-level elements occupy the full line by default (full document flow)

Common block-level elements:

P label H1~~h6 ul li oi li hr table

Elements in two rows

Common in-line elements

A span img input

Inline element Code!

#sp1, #sp2 {    height:100px;     width:100px;     Border:solid 2px #FF0000;
Display:block;
}

< span = "SP1" > Hello </span>
<span= "SP2" > Hello 2</span>

Inline element Features:

1, size affected by text area unaffected by Heigh width

2, does not occupy one line

span is only for single text

3 inline element block level elements

Display:block

Row variable block

Display:inline

Block becomes line

Display:inline-block;

Characteristics of existing block-level elements with inline elements

(Height-width recovery to impact

Don't stand alone one line

）

float: float up or down

#d1, #d2 {height:100px;width:100px;border:solid 2px #FF0000;
float:left<!--left float--
<!--float:right Right float--

<!--Float:top floating on

<!--Float:bottom Floating

}
#d3
{

Height:100px;width:100px;border:solid 2px #FF0000;

}

<= "D1"> hehe </div><  = "D2" > haha </div>

<div = "D3" > Haha </div>

D3 height width has no effect because it is affected by the above float to use clear:both; clear both sides floating

Three, Box model

Inner pitch padding

< Div = "D1" > Hello <Div>

#d1 {height:100px; width:100px; border:solid 2px #FF0000;
padding:10px;
    }

paddding:10px

paddding:10px 20px

padding:10px0 20px 30px up or down

padding:10px 20px 30px 40px upper right lower left

Outside pitch margin

< Div = "D1" > tomorrow </div>

<div= "D2" > Nurture </div>

#d1, #d2 {height:100px; width:100px; border:solid 2px #FF0000;
}
#d2
{
margin-top:10px;
}

Can I use padding margin for inline elements?

< span = "D1" ></ span >

#d1 {Border:solid 2px #FF0000;
padding:10px;}

Inline elements have an effect on padding

#d1 {Border:solid 2px #FF0000;
Margin:left;}

< span = "D1" ></ span >

Margin is only about the element in the row

*｛

padding:0px;

margin:0px;

｝

All internal and external spacing is equal to 0

Four, relative positioning and absolute positioning

Absolute positioning:

1, out-of-document flow is not covered with a single row unaffected by floats

2, when the position of the absolute positioning element is set, it will be affected by the left right top bottom

Relative positioning: position:relative;

1 setting relative positioning is not out of document flow

2 sets the relative orientation relative to the element's parent tag.

(because the label is not out of the flow of the document, he occupies the position around it)

Fixed element position:fixed

9.22 Classroom Records