边框样式属性 | border-top-style

border-top-style

border-top-style CSS属性设置元素的顶部的线条样式border。

/* Keyword values */
border-top-style: none;
border-top-style: hidden;
border-top-style: dotted;
border-top-style: dashed;
border-top-style: solid;
border-top-style: double;
border-top-style: groove;
border-top-style: ridge;
border-top-style: inset;
border-top-style: outset;

/* Global values */
border-top-style: inherit;
border-top-style: initial;
border-top-style: unset;

注意：规范没有定义不同风格的边界如何连接角落。

返回值	none
适用元素	all elements. It also applies to ::first-letter.
是否是继承属性	no
适用媒体	visual
计算值	as specified
Animation type	discrete
正规顺序	the unique non-ambiguous order defined by the formal grammar

语法

该border-top-style属性被指定为从border-style属性中选择的单个关键字。

正式语法

<br-style>where 
<br-style> = none | hidden | dotted | dashed | solid | double | groove | ridge | inset | outset

示例

HTML

<table>
  <tr>
    <td class="b1">none</td>
    <td class="b2">hidden</td>
    <td class="b3">dotted</td>
    <td class="b4">dashed</td>
  </tr>
  <tr>
    <td class="b5">solid</td>
    <td class="b6">double</td>
    <td class="b7">groove</td>
    <td class="b8">ridge</td>
  </tr>
  <tr>
    <td class="b9">inset</td>
    <td class="b10">outset</td>
  </tr>
</table>

CSS

/* Define look of the table */
table {
  border-width: 2px;
  background-color: #52E385;
}
tr, td {
  padding: 3px;
}

/* border-top-style example classes */
.b1 {border-top-style: none;}
.b2 {border-top-style: hidden;}
.b3 {border-top-style: dotted;}
.b4 {border-top-style: dashed;}
.b5 {border-top-style: solid;}
.b6 {border-top-style: double;}
.b7 {border-top-style: groove;}
.b8 {border-top-style: ridge;}
.b9 {border-top-style: inset;}
.b10 {border-top-style: outset;}

结果

规范

Specification	Status	Comment
CSS Backgrounds and Borders Module Level 3The definition of 'border-top-style' in that specification.	Candidate Recommendation	No significant change.
CSS Level 2 (Revision 1)The definition of 'border-top-style' in that specification.	Recommendation	Initial definition.

浏览器兼容性

Feature	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari
Basic Support	1	(Yes)	11	5.5	9.2	1

Feature	Android	Chrome for Android	Edge mobile	Firefox for Android	IE mobile	Opera Android	iOS Safari
Basic Support	?	?	(Yes)	(Yes)1	?	?	?

在Firefox 50之前，圆角（带border-radius）的边框样式总是呈现为好像border-top-style被设定成solid一样。这已在Firefox 50中修复。