border-top：<line-width> || <line-style> || <color>
<line-width> = <length> | thin | medium | thick
<line-style> = none | hidden | dotted | dashed | solid | double | groove | ridge | inset | outset
默認(rèn)值：看每個(gè)獨(dú)立屬性
適用于：所有元素
繼承性：無(wú)
動(dòng)畫性：看每個(gè)獨(dú)立屬性
計(jì)算值：看每個(gè)獨(dú)立屬性
相關(guān)屬性：[ border ] || [ border-right ] || [ border-bottom ] || [ border-left ]
| Values | IE | Firefox | Chrome | Safari | Opera | iOS Safari | Android Browser | Android Chrome |
|---|---|---|---|---|---|---|---|---|
| Basic Support | 6.0+ | 2.0+ | 4.0+ | 3.1+ | 3.5+ | 3.2+ | 2.1+ | 18.0+ |