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    border-top-left-radius Redirect 1

    Summary

    The border-top-left-radius CSS property sets the rounding of the top-left corner of the element. The rounding can be a circle or an ellipse, or if one of the value is 0 no rounding is done and the corner is square.

    border-radius.png

    A background, being an image or a color, is clipped at the border, even a rounded one; the exact location of the clipping is defined by the value of the background-clip property.

    If the value of this property is not set in a border-radius shorthand property that is applied to the element after the border-top-left-radius CSS property, the value of this property is then reset to its initial value by the shorthand property.

    • Initial value 0
    • Applies to all elements; but UA are not required to apply to table and inline-table elements when border-collapse is collapse. The behavior on internal table elements is undefined for the moment.
    • Inherited no
    • Percentages refer to the corresponding dimension of the border box
    • Media visual
    • Computed value two absolute length or percentages
    • Animatable yes, as a length, percentage or calc(); when both values are lengths, they are interpolated as lengths; when both values are percentages, they are interpolated as percentages; otherwise, both values are converted into a calc() function that is the sum of a length and a percentage (each possibly zero), and these calc() functions have each half interpolated as real numbers.
    • Canonical order the unique non-ambiguous order defined by the formal grammar

    Syntax

    Formal syntax: [ <length> | <percentage> ]{1,2}  
    border-top-left-radius: radius               /* the corner is a circle    */  E.g. border-top-left-radius: 3px
    border-top-left-radius: horizontal vertical  /* the corner is an ellipsis */  E.g. border-top-left-radius: 0.5em 1em
    
    border-top-left-radius: inherit
    

    where:

    radius
    Is a <length> or a <percentage> denoting the radius of the circle to use for the border in that corner.
    horizontal
    Is a <length> or a <percentage> denoting the horizontal semi-major axis of the ellipsis to use for the border in that corner.
    vertical
    Is a <length> or a <percentage> denoting the vertical semi-major axis of the ellipsis to use for the border in that corner.

    Values

    <length>
    Denotes the size of the circle radius or the semi-major and semi-minor axes of the ellipsis. It can be expressed in any unit allowed by the CSS <length> data types. Negative values are invalid.
    <percentage>
    Denotes the size of the circle radius, or the semi-major and semi-minor axes of the ellipsis, using percentage values. Percentages for the horizontal axis refer to the width of the box, percentages for the vertical axis refer to the height of the box. Negative values are invalid.

    Examples

    Live example Code
     
    An arc of circle is used as the border
    div {
      border-top-left-radius: 40px 40px;
    }
     
    An arc of ellipse is used as the border
    div {
      border-top-left-radius: 40px 20px;
    }
    
     
    The box is a square: an arc of circle is used as the border
    div 
      border-top-left-radius: 40%;
    }
    
     
    The box is not a square: an arc of ellipse is used as the border
    div {
      border-top-left-radius: 40%;
    }
    
     
    The background color is clipped at the border
    div {
      border-top-left-radius:40%;
      border-style: black 3px double;
      background-color: rgb(250,20,70);
      background-clip: content-box;
    }
    

    Specifications

    Specification Status Comment
    CSS Backgrounds and Borders Module Level 3 Candidate Recommendation Initial specification

    Browser compatibility

    Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
    Basic support 0.2 -webkit

    1.0 (1.0) - 12.0 (12.0)-moz
    but with a non-standard name:
    -moz-border-radius-topleft

    9.0 10.5 3.0 (522)-webkit
    4.0 4.0 (2.0) 5.0 (532.5)
    Percentages 4.0 1.0 (1.0) with a bug (see note) 9.0 10.5 5.0 (532.5)
    4.0 (2.0)
    Elliptical corners 0.2 3.5 (1.9.1) 9.0 10.5 3.0 (522 )
    Feature Android Firefox Mobile (Gecko) IE Phone Opera Mobile Safari Mobile
    Basic support ? ? ? ? ?

    Browser notes

    Gecko

    • The prefixed version (allowed from Firefox 1 to Firefox 12) of this property uses a different name, -moz-border-radius-topleft, than the final property as Mozilla implemented it before the final name was coined.
    • Before Firefox 4, the <percentage> was relative to the width of the box even when specifying the radius for a height). This implied that -moz-border-radius-topleft was always drawing an arc of circle, and never an ellipse, when followed by a single value.
    • Gecko is not able to display dotted and dashed rounded corners correctly: it displays them as solid (bug 382721).

    See also

    The border-radius-related CSS properties: the CSS shorthand border-radius, the properties for the other corners: border-top-right-radius, border-bottom-right-radius, and border-bottom-left-radius.

    Document Tags and Contributors

    Contributors to this page: Sheppy
    Last updated by: Sheppy,
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