Css container background colors

background

The background shorthand CSS property sets all background style properties at once, such as color, image, origin and size, or repeat method. Component properties not set in the background shorthand property value declaration are set to their default values.

Try it

Constituent properties

This property is a shorthand for the following CSS properties:

Syntax

/* Using a */ background: green; /* Using a and */ background: url("test.jpg") repeat-y; /* Using a and */ background: border-box red; /* A single image, centered and scaled */ background: no-repeat center/80% url("../img/image.png"); /* Global values */ background: inherit; background: initial; background: revert; background: revert-layer; background: unset; 

The background property is specified as one or more background layers, separated by commas.

The syntax of each layer is as follows:

• Each layer may include zero or one occurrences of any of the following values:
  • The value may only be included immediately after , separated with the ‘/’ character, like this: » center/80% «.
  • The value may be included zero, one, or two times. If included once, it sets both background-origin and background-clip . If it is included twice, the first occurrence sets background-origin , and the second sets background-clip .
  • The value may only be included in the last layer specified.

  Values

  See background-clip and background-origin . Default: border-box and padding-box respectively.

  See background-color . Default: transparent .

  The following three lines of CSS are equivalent:

  background: none; background: transparent; background: repeat scroll 0% 0% / auto padding-box border-box none transparent; 

  Accessibility concerns

  Browsers do not provide any special information on background images to assistive technology. This is important primarily for screen readers, as a screen reader will not announce its presence and therefore convey nothing to its users. If the image contains information critical to understanding the page’s overall purpose, it is better to describe it semantically in the document.

  Formal definition

  • background-image : none
  • background-position : 0% 0%
  • background-size : auto auto
  • background-repeat : repeat
  • background-origin : padding-box
  • background-clip : border-box
  • background-attachment : scroll
  • background-color : transparent
  • background-position : refer to the size of the background positioning area minus size of background image; size refers to the width for horizontal offsets and to the height for vertical offsets
  • background-size : relative to the background positioning area
  • background-image : as specified, but with url() values made absolute
  • background-position : as each of the properties of the shorthand:
    • background-position-x : A list, each item consisting of: an offset given as a combination of an absolute length and a percentage, plus an origin keyword
    • background-position-y : A list, each item consisting of: an offset given as a combination of an absolute length and a percentage, plus an origin keyword
    • background-color : a color
    • background-image : discrete
    • background-clip : a repeatable list of
    • background-position : a repeatable list of
    • background-size : a repeatable list of
    • background-repeat : discrete
    • background-attachment : discrete

    Formal syntax

    background =
    [ # , ]?

    =
    ||
    [ / ]? ||
    ||
    ||
    ||
    

    =
    ||
    ||
    [ / ]? ||
    ||
    ||
    ||
    

    =
    |
    none

    =
    [ left | center | right | top | bottom | ] |
    [ left | center | right | ] [ top | center | bottom | ] |
    [ center | [ left | right ] ? ] && [ center | [ top | bottom ] ? ]

    =
    [ | auto ] |
    cover |
    contain

    =
    repeat-x |
    repeat-y |
    [ repeat | space | round | no-repeat ]

    =
    scroll |
    fixed |
    local

    =
    border-box |
    padding-box |
    content-box

    =
    |

    =
    |

    =
    url( * ) |
    src( * )

    Examples

    Setting backgrounds with color keywords and images

    HTML

    p class="topbanner"> Starry skybr /> Twinkle twinklebr /> Starry sky p> p class="warning">Here is a paragraphp> p>p> 

    CSS

    .warning  background: pink; > .topbanner  background: url("starsolid.gif") #99f repeat-y fixed; > 

    Result

    Specifications

    Browser compatibility

    BCD tables only load in the browser

    See also

    Found a content problem with this page?

    This page was last modified on Jul 18, 2023 by MDN contributors.

    Your blueprint for a better internet.

    MDN

    Support

    Our communities

    Developers

    Visit Mozilla Corporation’s not-for-profit parent, the Mozilla Foundation.
    Portions of this content are ©1998– 2023 by individual mozilla.org contributors. Content available under a Creative Commons license.

    Источник

    HTML Background Color Tutorial – How to Change a Div Background Color, Explained with Code Examples

    

    One of the most common things you may have to do as a web developer is to change the background-color of an HTML element. But it may be confusing to do if you do not understand how to use the CSS background-color property.

    In the article, we discuss

    • the default background color value of an HTML element
    • how to change the background color of a div, which is a very common element
    • which parts of the CSS box model are affected by the background-color property, and
    • the different values this property can take.

    Default Background Color of an Element

    The default background color of a div is transparent . So if you do not specify the background-color of a div, it will display that of its parent element.

    Changing the Background Color of a Div

    In this example, we will change the background colors of the following divs.

     
    I love HTML
     
    I love CSS
     
    I love JavaScript
     

    Without any styling, this will translate to the following visually.

    

    Let’s change the background color of the divs by adding styles to the classes. You can follow along by trying the examples in an HTML file.

     .div-1 < background-color: #EBEBEB; >.div-2 < background-color: #ABBAEA; >.div-3  
    I love HTML
     
    I love CSS
     
    I love JavaScript
      

    This will result in the following:

    

    Cool! We have successfully changed the background color of this div. Next, let’s get to know more about this property. Let’s see how the background-color property affects parts of the CSS-box model.

    Background Color and the CSS Box Model

    According to the CSS box model, all HTML elements can be modeled as rectangular boxes. Every box is composed of 4 parts as shown in the diagram below.

    

    You can read up on the box model if you are not familiar with it. The question is, which part of the box model is affected when you change the background color of a div? The simple answer is the padding area and the content area. Let’s confirm this by using an example.

     body < background-color: #ABBAEA; >.child  
    This is the parent div which contains the div we are testing
     
    This example shows that changing the background color of a div does not affect the border and margin of the div.
     
     
     

    

    From the example above, we can see that the margin area and the border area are not affected by the change in background color. We can change the color of the border using the border-color property. The margin area remains transparent and reflects the background color of the parent container.

    Finally, let’s discuss the values the background-color property can take.

    Background-color Values

    Just like the color property, the background-color property can take six different values. Let’s consider the three most common values with an example. In the example, we set the background-color of the div to red with different values.

     /* Keyword value/name of color */ .div-1 < background-color: red; >/* Hexadecimal value */ .div-2 < background-color: #FF0000; >/* RGB value */ .div-3  
    The background property can take six different values.
     
     
    The background property can take six different values.
     
     
    The background property can take six different values.
     
      

    Notice that they all result with the same background color.

    

    Other values the background-color property can take include HSL value, special keyword values and global values. Here are examples of each of them.

    /* HSL value */ background-color: hsl(0, 100%, 25%; /* Special keyword values */ background-color: currentcolor; background-color: transparent; /* Global values */ background-color: inherit; background-color: initial; background-color: unset; 

    You can read more on each of these values here.

    Extra Note

    When setting the background color of an element, it is important to ensure that the contrast ratio of the background color and the color of the text it contains is high enough. This is to ensure that people with low vision can easily read the text.

    

    The contrast between the background color of the first div and the color of the text is not high enough for everyone to see. So unless you are the only one using the website you are building and you have very good eyesight, you should avoid such color combinations.

    The second div has a much better contrast ratio between the background color and the color of the text . Thus, it is more accessible and clearer for people to read.

    Conclusion

    In this article, we saw how you can change the background-color of a div. We also discussed which parts of the CSS box model are affected by the change in background-color. Finally, we discussed the values the background-color property can take.

    I hope you found this article useful. Thanks for reading.

    Источник

    background-color

    The background-color CSS property sets the background color of an element.

    Try it

    Syntax

    /* Keyword values */ background-color: red; background-color: indigo; /* Hexadecimal value */ background-color: #bbff00; /* Fully opaque */ background-color: #bf0; /* Fully opaque shorthand */ background-color: #11ffee00; /* Fully transparent */ background-color: #1fe0; /* Fully transparent shorthand */ background-color: #11ffeeff; /* Fully opaque */ background-color: #1fef; /* Fully opaque shorthand */ /* RGB value */ background-color: rgb(255 255 128); /* Fully opaque */ background-color: rgb(117 190 218 / 0.5); /* 50% transparent */ /* HSL value */ background-color: hsl(50 33% 25%); /* Fully opaque */ background-color: hsl(50 33% 25% / 0.75); /* 75% opaque, i.e. 25% transparent */ /* Special keyword values */ background-color: currentcolor; background-color: transparent; /* Global values */ background-color: inherit; background-color: initial; background-color: revert; background-color: revert-layer; background-color: unset; 

    The background-color property is specified as a single value.

    Values

    The uniform color of the background. It is rendered behind any background-image that is specified, although the color will still be visible through any transparency in the image.

    Accessibility concerns

    It is important to ensure that the contrast ratio between the background color and the color of the text placed over it is high enough that people experiencing low vision conditions will be able to read the content of the page.

    Color contrast ratio is determined by comparing the luminance of the text and background color values. In order to meet current Web Content Accessibility Guidelines (WCAG), a ratio of 4.5:1 is required for text content and 3:1 for larger text such as headings. Large text is defined as 18.66px and bold or larger, or 24px or larger.

    Formal definition

    Formal syntax

    Examples

    HTML

    div class="exampleone">Lorem ipsum dolor sit amet, consectetuerdiv> div class="exampletwo">Lorem ipsum dolor sit amet, consectetuerdiv> div class="examplethree">Lorem ipsum dolor sit amet, consectetuerdiv> 

    CSS

    .exampleone  background-color: transparent; > .exampletwo  background-color: rgb(153, 102, 153); color: rgb(255, 255, 204); > .examplethree  background-color: #777799; color: #ffffff; > 

    Result

    Specifications

    Browser compatibility

    BCD tables only load in the browser

    See also

    Found a content problem with this page?

    This page was last modified on Jul 18, 2023 by MDN contributors.

    Your blueprint for a better internet.

    MDN

    Support

    Our communities

    Developers

    Visit Mozilla Corporation’s not-for-profit parent, the Mozilla Foundation.
    Portions of this content are ©1998– 2023 by individual mozilla.org contributors. Content available under a Creative Commons license.

    Источник

    Читайте также:  Css float right position bottom