em | 易学教程

css中em小于1时chrome字体大小和firefox字体大小不一致的问题

阅读更多关于 css中em小于1时chrome字体大小和firefox字体大小不一致的问题

　　css中em设置为0.8，结果页面显示，chrome字体比firefox字体大了不少。 chrome有默认字体大小，默认为12px。设置的字体大小小于12px时，也是按照12px来显示。 firefox则是按照字体的实际大小显示。在css中单位长度用的最多的是px、em、rem，这三个的区别，可以看一下： https://www.cnblogs.com/wind-lanyan/p/6978084.html 可以改一下下css样式，使得chrome中显示小于12px的字体。下面内容转自： https://www.cnblogs.com/jiangxiaobo/p/5669976.html 　　可以使用Webkit 的内核的 -webkit-text-size-adjust 的私有 CSS 属性来解决，比如下面的代码就可以成功的解决，通过它即可实现字体大小不随终端设备或浏览器影响。样式定义如下：　　#chrome10px{ -webkit-text-size-adjust:none; font-size:10px; } 　　只要加了 -webkit-text-size-adjust:none; 字体大小就不受限制了。　　但是，在chrome更新到27版本之后就不可以用了。　　那此时应该怎么办呢？想一想，还是有办法解决的。　　chrome是支持css3的

使用rem实现移动端适配的简单方法

阅读更多关于使用rem实现移动端适配的简单方法

使用rem适配已经快一年了，感觉还是不错的，在这里记录一下。 ##1.原理 rem 是一个相对单位，相对的是根元素‘html’的字号。比如html的font-size:100px;那么1rem=100px；html的font-size:120px;那么1rem=120px；所以我们可以根据手机不同的尺寸，设置不同的根元素字体，来适应不同的屏幕。而且它兼容性好，从安卓2.1就支持rem。举个栗子： //在iPhone5下 html{ font-size:100px; } //在iPhone6下 html{ font-size:116px; } .box{ width:1rem;//在iPhone5下，width为100px;在iPhone6下,width为116px，从而实现了大小屏的适配 } ##2.设置基准我们依据什么来设置根目录的字号呢？两种方案 ###2.1css媒体查询宽度设置断点为什么是宽度？因为垂直方向的可以出滚动条，而水平方向出现滚动条就有点怪怪的了。 @charset "utf-8"; //iphone5 @media screen and (max-width: 374px){ html{ font-size: 85px; } } //iphone6 @media screen and (min-width: 375px)and(max-width:

Margin and padding using em

阅读更多关于 Margin and padding using em

When 1em is applied to an element, it takes the default value of the browser (usually, 16px) or the font-size value of its parent, right?. But I noticed that if I use something like margin-top: 1em in a h1 element (without using a reset stylesheet, and therefore, h1 is set to font-size: 32px ), then 1em is equal to 32px , even if its parent element is set to font-size: 16px . However, using something like font-size: 100%; solves the discrepancy. What am I missing? When 1em is applied to an element, it takes the default value of the browser (usually, 16px) or the font-size value of its parent,

02-body标签中相关标签

阅读更多关于 02-body标签中相关标签

02-body标签中相关标签今日内容：字体标签： h1~h6、<font>、<u>、<b>、<strong><em>、<sup>、<sub> 排版标签　　　<div> 、<span> 、 <br>、<hr>、<center>、<pre> 超链接 <a> 图片标签 <img> 一、字体标签字体标签包含：h1~h6、<font>、<u>、<b>、<strong><em>、<sup>、<sub> 标题标签h1~h6 标题使用 <h1> 至 <h6> 标签进行定义。 <h1> 定义最大的标题， <h6> 定义最小的标题。具有align属性，属性值可以是：left、center、right。 <h1>路飞学城</h1> <h2>路飞学城</h2> <h3>路飞学城</h3> <h4>路飞学城</h4> <h5>路飞学城</h5> <h6>路飞学城</h6> 字体标签<font>(已废弃) color="红色" 或 color="#ff00cc" 或 color="new rgb(0,0,255)" ：设置字体颜色。设置方式：单词 #ff00cc rgb(0,0,255) size ：设置字体大小。取值范围只能是：1至7。取值时，如果取值大于7那就按照7来算，如果取值小于1那就按照1来算。如果想要更大的字体，那就只能通过css样式来解决 face="微软雅黑" ：设置字体类型

How do responsive images work with `em` supplied as a length in `sizes`?

阅读更多关于 How do responsive images work with `em` supplied as a length in `sizes`?

How can browsers understand the em unit when used in a responsive image? <img alt="A giraffe" src="giraffe.jpg" srcset="giraffe@1.5x.jpg 600w, giraffe@2x.jpg 800w, [etc.]" sizes="(max-width: 40em) 40em"> This validates, and I'm not seeing warnings in browser consoles. But if the whole point of the image preloader is to fetch images before the CSS is downloaded and parsed, what does the browser use for em ? Is it just its default font-size that it applies to <html> ? Should I use rem for clarity? Is there a difference between the two when the user zooms? This isn't theoretical; I'm using em in

响应式布局之 px、em、 rem

阅读更多关于响应式布局之 px、em、 rem

一、写在前面的话　　作为一面前端开发者，对 px 、em 、 rem 应该是再熟悉不过了，但大多数小伙伴应该都和我一样仅仅停留在了解的层面，并不是实质性的掌握它们。本文对三者进行了详细的总结和详细说明，不熟悉的各位小伙伴阅读本文一定会有所收获，如果你对这三者已经了解的非常透彻，那本文可能对你的帮助不大。二、简述　　px、em、rem都是计量单位，都能表示尺寸，但是有有所不同，而且其各有各的优缺点。三、PX （pixel）　　Px 表示“绝对尺寸”（并非真正的绝对），实际上就是css中定义的像素（此像素与设备的物理像素有一定的区别），利用px设置字体大小及元素宽高等比较稳定和精确。Px的缺点是其不能适应浏览器缩放时产生的变化，因此一般不用于响应式网站。注： 1、像素 1024x768 的，表示的是水平方向是 1024 个像素点，垂直方向是 768个像素点。　　 2、以上所述 px 为 css 中定义的像素（以下简称 css 像素），与实际的物理像素是有区别的，早期电脑屏幕的物理像素与 css 像素相同，但是随着科技的发展，高精度屏幕开始出现在人们的视野中。以 iPhone 的 Retina　　屏为例，其物理像素与 css 像素关系见下图。　　为此移动端浏览器以及某些桌面浏览器引入了 devicePixelRatio（DPR 设备像素比）属性，其官方的定义为

Delphi: Center Specific Line in TRichEdit by Scrolling

阅读更多关于 Delphi: Center Specific Line in TRichEdit by Scrolling

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I have a Delphi 2007 TRichEdit with several lines in it. I want to scroll the richedit vertically such that a specific line number if approximately centered in the visible/display area of the richedit. For example, I want to write the code for CenterLineInRichEdit in this example: procedure CenterLineInRichEdit(Edit: TRichEdit; LineNum: Integer); begin ... Edit.ScrollTo(...); end; procedure TForm1.FormCreate(Sender: TObject); var REdit: TRichEdit; i: Integer; begin REdit := TRichEdit.Create(Self); REdit.Parent := Self; Redit.ScrollBars :=

jQuery/JavaScript: convert pixels to em in a easy way

阅读更多关于 jQuery/JavaScript: convert pixels to em in a easy way

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I am looking for a easy way to add a line of code to a plugin of mine, to convert a couple of pixel values into em values, because the layout of my project needs to be in ems. Is there an easy way to do this, because I don't want to add a third-party plugin to the site. Won't post the code here, as it has nothing to do with the plugin it self. Thanks. Example: 13px -> ??em 回答1: I think your question is very important. Since the classes of display resolutions are rapidly increasing, using em positioning to support wide range of screen

Why can't I decrease the line-height of this text?

阅读更多关于 Why can't I decrease the line-height of this text?

http://jsfiddle.net/mJxn4/ This is very odd: I have a few lines of text wrapped in an <em> tag. No matter what I do, lowering the value for line-height below 17px has no effect. I can bump the line-height up to greater than 17px and it'll apply, but I can't get it lower than 17px. The CSS in question is: #others .item em { font-size: 13px; line-height: 17px; } Try adjusting the line height both higher and lower and run the updated fiddle after each change, and you'll see what I mean. Why would this be? No line-height is specified anywhere else in the CSS, so nothing is overriding it. That

how efficently may i use filter_var($email, FILTER_VALIDATE_EMAIL).?

阅读更多关于 how efficently may i use filter_var($email, FILTER_VALIDATE_EMAIL).?

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I have tried out some code below but one major thing i missed out is email validation...but now i am trying to add filter_var($email, FILTER_VALIDATE_EMAIL) in my code..but confused where to include it in my code. Please may I know how and were can I add email validation in my code. please help me out and i beg you pardon i am wrong. here goes the /*.php*/ code <?php require_once 'DB_Functions.php'; $db = new DB_Functions(); // json response array $response = array("error" => false); if (!empty($_POST['fname']) && !empty($_POST['lname']) &&

订阅 em