是否有可用的CSS规则可以删除之前在样式表中为特定元素设置的任何样式?
一个很好的例子可能是在一个移动优先的RWD站点中，在这个站点中，用于小屏幕视图中的特定元素的许多样式都需要“重置”或删除桌面视图中的相同元素。
一个CSS规则可以实现如下功能:
.element {
all: none;
}
使用示例:
/* mobile first */
.element {
margin: 0 10;
transform: translate3d(0, 0, 0);
z-index: 50;
display: block;
etc..
etc..
}
@media only screen and (min-width: 980px) {
.element {
all: none;
}
}
因此，我们可以快速删除或重新设置样式，而不必声明每个属性。
当前回答
你提到了移动优先的网站……对于响应式设计，用大屏样式覆盖小屏幕样式当然是可能的。但你可能不需要这样做。
试试这个:
.thisClass {
/* Rules for all window sizes. */
}
@media all and (max-width: 480px) {
.thisClass {
/* Rules for only small browser windows. */
}
}
@media all and (min-width: 481px) and (max-width: 960px) {
.thisClass {
/* Rules for only medium browser windows. */
}
}
@media all and (min-width: 961px) {
.thisClass {
/* Rules for only large browser windows. */
}
}
这些媒体查询不会重叠，因此它们的规则不会相互覆盖。这使得单独维护每一组样式更加容易。
其他回答
如果你碰巧在构建系统中使用sass，一种在所有主流浏览器中都能工作的方法是用:not()选择器包装你所有的样式导入，就像这样…
:not(.disable-all-styles) {
@import 'my-sass-file';
@import 'my-other-sass-file';
}
然后你可以在容器上使用disable类，子内容不会有任何你的样式。
<div class="disable-all-styles">
<p>Nothing in this div is affected by my sass styles.</p>
</div>
当然，现在所有的样式都将以:not()选择器作为前缀，所以这有点难看，但效果很好。
你提到了移动优先的网站……对于响应式设计，用大屏样式覆盖小屏幕样式当然是可能的。但你可能不需要这样做。
试试这个:
.thisClass {
/* Rules for all window sizes. */
}
@media all and (max-width: 480px) {
.thisClass {
/* Rules for only small browser windows. */
}
}
@media all and (min-width: 481px) and (max-width: 960px) {
.thisClass {
/* Rules for only medium browser windows. */
}
}
@media all and (min-width: 961px) {
.thisClass {
/* Rules for only large browser windows. */
}
}
这些媒体查询不会重叠，因此它们的规则不会相互覆盖。这使得单独维护每一组样式更加容易。
更好的解决方案
下载“复制/粘贴”样式表，将css属性重置为默认值(UA样式): https://github.com/monmomo04/resetCss.git
Thanks@Milche Patern! I was really looking for reset/default style properties value. My first try was to copy the computed value from the browser Dev tool of the root(html) element. But as it computed, it would have looked/worked different on every system. For those who encounter a browser crash when trying to use the asterisk * to reset the style of the children elements, and as I knew it didn't work for you, I have replaced the asterisk "*" with all the HTML tags name instead. The browser didn't crash; I am on Chrome Version 46.0.2490.71 m. At last, it's good to mention that those properties will reset the style to the default style of topest root element but not to the initial value for each HTML element. So to correct this, I have taken the "user-agent" styles of webkit based browser and implemented it under the "reset-this" class.
Useful link:下载“复制/粘贴”样式表，将css属性重置为默认值(UA样式): https://github.com/monmomo04/resetCss.git
用户代理风格: 浏览器默认的HTML元素CSS http://trac.webkit.org/browser/trunk/Source/WebCore/css/html.css
Css的特殊性(注意特殊性): https://css-tricks.com/specifics-on-css-specificity/
https://github.com/monmomo04/resetCss.git
我不建议使用这里标记为正确的答案。它是一个巨大的CSS，试图覆盖一切。
我建议您评估如何根据具体情况从元素中删除样式。
比如说，为了搜索引擎优化的目的，你需要在一个没有实际标题的页面上包含一个H1。你可能想让该页面的导航链接为H1，但当然你不希望该导航链接在页面上显示为一个巨大的H1。
您应该做的是将该元素包装在h1标记中并检查它。看看h1元素具体应用了哪些CSS样式。
假设我看到以下样式应用于元素。
//bootstrap.min.css:1
h1 {
font-size: 65px;
font-family: 'rubikbold'!important;
font-weight: normal;
font-style: normal;
text-transform: uppercase;
}
//bootstrap.min.css:1
h1, .h1 {
font-size: 36px;
}
//bootstrap.min.css:1
h1, .h1, h2, .h2, h3, .h3 {
margin-top: 20px;
margin-bottom: 10px;
}
//bootstrap.min.css:1
h1, h2, h3, h4, h5, h6, .h1, .h2, .h3, .h4, .h5, .h6 {
font-family: inherit;
font-weight: 500;
line-height: 1.1;
color: inherit;
}
//bootstrap.min.css:1
h1 {
margin: .67em 0;
font-size: 2em;
}
//user agent stylesheet
h1 {
display: block;
font-size: 2em;
-webkit-margin-before: 0.67em;
-webkit-margin-after: 0.67em;
-webkit-margin-start: 0px;
-webkit-margin-end: 0px;
font-weight: bold;
}
现在你需要针点准确的样式，这是应用到H1和在css类中取消设置。它看起来会像下面这样:
.no-style-h1 {
font-size: unset !important;
font-family: unset !important;
font-weight: unset !important;
font-style: unset !important;
text-transform: unset !important;
margin-top: unset !important;
margin-bottom: unset !important;
line-height: unset !important;
color: unset !important;
margin: unset !important;
display: unset !important;
-webkit-margin-before: unset !important;
-webkit-margin-after: unset !important;
-webkit-margin-start: unset !important;
-webkit-margin-end: unset !important;
}
这是更干净，不只是转储一个随机的代码团到你的css，你不知道它实际上在做什么。
现在可以将这个类添加到h1中
<h1 class="no-style-h1">
Title
</h1>
As other answers have mentioned, the CSS property all set to the value unset seems to override all CSS properties without knowing which properties are in play. However, this did not work for me while adding custom CSS in a Wordpress site, as the all property was not recognized by the Wordpress custom CSS editor, and did not reflect changes in Microsoft Edge. Instead, what worked for me was a brute-force override, that is, to identify every property used in the webpage element and manually reset each one of them. The way to identify the CSS properties being used by an element is to inspect the element with your web browser, and go through the 'Styles' tab.
