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Summary of CSS DIV usage_html/css_WEB-ITnose

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2016-06-24 11:40:481061browse

(original link:)


CCS = Cascading Style Sheets


Inline style sheet (not recommended):


Internal style sheet (not recommended):


External style sheet (usually under the title of the head):


CSS Writing structure:

{

; : ;

… …

}

For example:

p {

color: #F00;

font-size: 12px;

}


Basic type selector:

  • Tag selector: written inside <> tag, such as: p{}. Select all contents of this label. Support custom labels.
  • Class selector: starting with ".", such as: .30font{}, means selecting all elements with class "30font".
  • id selector: starts with "#".

  • Composite type selector:

  • Pseudo-class selector: separated by ":", For example, "a:link", "a:hover", "a:active" (mouse pressed), "a:visited" for ; or ".myClass:hover"
  • Group selector: separated by ",", select several elements at the same time, such as: "a, p, h3"
  • tag specifies the selector: such as p.aa means p with class="aa" Tag, p#aa represents the p tag with id="aa"
  • contains selectors: separated by spaces, indicating B inside A, such as "#top a" indicating < inside id="top" ;a> tag
  • sibling adjacent selectors: separated by " ", such as "h1 p" means

    tag

  • attribute selector adjacent to

    : Separated by "[]", such as "p[align]" means

    tags with align attribute

  • Wildcard selector: "*", means selecting all elements

  • Font and text properties:

  • font-family: font name
  • font-size: font Size needs to be in unit px
  • font-weight: bold. bold, bolder, lighter, 100, 200, ... 900 (meaning 100, 200...)
  • font-style: font style. normal, italic, oblique (also italic, only valid for some special fonts)
  • font-variant: Convert English letters to uppercase. normal: normal font, small-caps: small uppercase font
  • line-hight: line height
  • text-transform: capitalize: capitalize the first letter, uppercase: all capitals, lowercase: All lowercase, none: unchanged
  • text-decoration: text decoration. underline, overline, line-through, blink, none, there can be multiple, separated by spaces
  • color: color
  • text-indet: first line indent (requires unit)
  • text-align: text alignment, left, right, center, justify (justify both ends)
  • letter-spacing: word spacing (requires unit px)

  • Background attributes:

  • background-color: background color
  • background-image: background image (takes precedence over background color) )
  • background-repeat: Whether to tile the background image. repeat (default), no-repeat, repeat-x, repeat-y (horizontal and vertical tiles)
  • background-attachment: whether to follow the scroll bar movement. fixed: do not move, scroll: move (default)
  • background-position: background positioning, the relative displacement of the origin coordinates (x, y) of the upper left corner of the background image, or right, left, top, bottom, center
  • Background attributes can be written together. List the attribute values ​​and separate them with spaces, such as:

    body{

    background: #F00 url(images/bg.jpg) no- repeat fixed 50px 100px;

    }

    背景平铺:repeat-x 或 repeat-y,把图片按x轴或y轴(横向或竖向)平铺


    优先级排序:默认 < 标签 < class < ID


    框模型(或盒模型):

  • 内联对象,按行显示:display:inline,由line-hight决定行高。如

    ,

  • 块对象,按块显示:display:block,由width和height决定宽和高,默认占一行。如
  • 内联对象转换为块对象后,就可以使用width和height属性了:a{display:block; width=10px; height:20px;}


  • padding:内填充(分top, bottom, left, right)
  • margin:外边距(分top, bottom, left, right)
  • border:边框(分top, bottom, left, right)
  • width:内容的宽度
  • height:内容的高度
  • 注:当两个元素上下排列时,他们间的margin会自动合并(都不是float或绝对定位的情况下)


    border的属性(分top, bottom, left, right):

  • style:线条样式(dotted, solid, double, 等)
  • width:粗细(单位px)
  • color:颜色
  • 可以缩写:border: solid 1px #FFF;

    单独设置一条边:

  • border-bottom: solid 2px #00F;
  • border-bottom-width: 2px;
  • (注:后面会覆盖前面的)


    margin和padding的设置:

  • margin: 1px (上下左右)
  • margin: 1px 2px 3px 4px; (上 右 下 左)
  • margin: 1px 2px; (上下 左右)
  • margin: 1px 2px 3px; (上 左右 下)
  • (注:padding的设置方法跟margin一样)


    浮动(float):

  • 浮动到普通流的上一层
  • float: left,浮动后向左,直到左边碰到边界或碰到同一层元素的右边界
  • float: right,浮动后向右,直到右边碰到边界或碰到同一层元素的左边界

  • 清理(clear):

  • 使浮动层继续在普通流保留占位
  • clear: both, left, right,应用于普通流,使普通流根据上一层的占位情况来决定自己的位置
  • 一般可以在浮动层和普通流直接加一个clear div来分隔排版,如:


    Center the block horizontally:

    1. margin left and right: auto (eg: margin:0px auto;)
    2. The block must have a specific width value (width)

    Note: The body has a margin of 8px by default. Cancel method: body{margin:0px;}

    Center the block vertically (less commonly used):

    1. width:500px; height:200px; position: absolute; top:50%; left:50%; margin-top:-100px; margin-left:-250px;

    Center text within the block:

    1. Center horizontally: text- align: center
    2. Vertically centered: line height = box height, such as: height:200px; line-height:200px (one line fills the entire div)


    ul list:

  • There is padding and margin by default. Cancel method: ul{padding:0px; margin:0px;}
  • list-style: List style (none, )
  • list-style-image:url(images/a.jpg);
  • Horizontal: li{float:left}
  • Set the dividing line: li{ background:url(images/1.png) no-repeat bottom center;}

  • Positioning (via position attribute):

  • static: Default positioning method, displayed by row or block.
  • relative: relative positioning, the element is offset by a certain distance (use top, right, bottom, left to position relative to the original position, the original space occupied will not be released)
  • absolute: element Removed completely from the document flow (similar to float) and positioned relative to its parent box (using top, right, bottom, left positioning). For example: #aaa{position:absolute; top:100px; left:50px;}
  • fixed: similar to absolute, except that the positioning is at a distance from the browser window. (Can be used to make floating ads)
  • Note: If they overlap, you can use the z-index attribute to determine who is on top, and the one with the larger value is on top.


    Size:

  • Fixed value: such as width: 100px;
  • missing Default value: leave it blank
  • Percent: the percentage of the parent box, such as width: 80%;
  • min-height, min-width: the minimum height and width of the element
  • max-height, max-width: the maximum height and width of the element

  • Handling when content exceeds the parent box:

  • overflow:hidden: The exceeded content is cut
  • overflow:scroll: The scroll bar is always displayed
  • overflow:auto: When the content is cut, Show scroll bars (the default value for body and textarea is auto)
  • overflow-x:hidden: Disable horizontal scroll bars
  • overflow-y:scroll: Always display vertical scroll bars
  • Note: If the parent box does not set height, the parent box will be raised until it reaches max-height.


    Browser scroll bar settings:

    For example: html{

    scrollbar-base-color:# F00;

    }

    Note: It seems to be only valid for IE.




    Photoshop cutting process:

    1. Use guides
    2. Use the slice tool
    3. Cancel the background and make the image transparent
    4. Save as web format...
    5. Save: slice : All user slices
    6. Save
    7. Rename

    Original article, please indicate the reprint from Clement-Xu’s csdn blog. )