通常用户看到的页面的样式会受到三层控制，第一层是浏览器的默认样式，第二层是网页定义样式，第三层是用户自定义样式。和CSS一样，后面的优先级高于前面的，也就是说网页定义样式可以覆盖浏览器的默认样式，而用户自定义样式优先级最高。实际情况是虽然浏览器都或多或少提供了用户自定义样式的功能，但是极少数会有用户去自定义，一般用也是高级用户。而浏览器默认的样式往往在不同的浏览器、不同的语言版本甚至不同的系统版本都有不同的设置，这就导致如果直接利用默认样式的页面在各个浏览器下显示非常不一致，于是就有了类似YUI的reset之类用来尽量重写浏览器的默认设置保证各个浏览器样式一致性的做法。

拿字体来说，各个浏览器默认的字体种类、字体大小和字体行高都不一样，比如IE8的中文版在Windows XP下显示网页时默认字体是宋体，而英文版肯定不会如此。所以我们需要统一设置默认的字体样式，以便实现一致的显示效果来保证设计的一致性和提高开发效率。

以后准备使用如下默认字体样式：

body{

 font: 12px/1.5 arial;

}

字体：arial

我们页面的绝大部分内容字符都是中文，毫无疑问目前为止在网页上最常用也是最通用的显示中文的字体是宋体，但是宋体在显示英文、数字和英文符号时过于糟糕，比如©字符，所以我们一般期望通过CSS来实现用更好的字体样式来显示它们，然后用宋体来显示中文和中文符号。之所以选择arial是因为：

Windows和Mac都预装了这款字体，应该是使用最广泛的网页字体了。它的潜在对手tahoma和helvetica就没有这么幸运了。

视觉设计的专业人士可能会认为在Windows中使用tahoma、在Mac中使用helvetica更好，比如淘宝的默认字体样式是font: 12px/1 Tahoma, Helvetica, Arial, "\5b8b\4f53", sans-serif;

这是一个很不错的选择，但是你也会发现Google、YAHOO、Youtube、Bing甚至MSN的新版都使用arial作为第一默认字体。所以从美观和可读性上来讲arial应该是完全可以接受的。

一般情况下设置font-family都会在最后设置通用字体族以保证其安全性，比如Google的设置为font-family:arial,sans-serif;，但是至少在非中文版的Win7下当编码是GBK时，IE8会因sans-serif来渲染宋体，导致字体出现变形，这就是为什么淘宝需要在sans-serif前加上宋体而Google无需这样做的原因。

因为中文字体的选择非常有限，所以目前所有的主流浏览器都设置使用宋体来显示中文。Baidu的首页和搜索结果页使用font-family:arial;可以从侧面说明这样做的安全性。可能有人注意到Firefox中国版默认显示的中文字体是微软雅黑，这是因为谋智网络擅自修改了用户自定义样式，不允许网页的样式覆盖浏览器设置的样式。也是由于类似的情况，我们要弹性设计网页非常重要。

使用英文字体作为第一默认字体会导致的问题之一就是中英文以及符号混排时的对齐问题、通过设置行高和hasLayout能解决绝大部分情况，但是都不会很完美，如果把字体改成“宋体”能彻底的解决问题。很明显，这个问题只出现在IE上。所以，如果你的网站很少使用英文、数字和英文符号，那么直接设置{font-family:\5b8b\4f53;}也是很合理的选择。

大小：12px

12px是宋体能显示的极限，虽然微软雅黑能显示更小的字体，但目前的应用环境尚未成熟。由于宋体基本上是目前显示中文唯一的通用Web字体，所以12px成为最常用的字体大小。我们当然可以依据产品的需要来修改这个默认值。

不用考虑基于字体大小（em）的设计。

在Chrome3.0之后的中文版中，字体大小最小值是12px，比如你设置最小字体为10px，最后也变成12px。

行高：1.5倍

这是一个经验值，不同的产品对这个值要求可能不同，但我们一般会设置最常用的为默认值。比如YUI的font中是font:13px/1.231 arial,helvetica,clean,sans-serif;即字体大小默认值是13px，行高是13*1.231=16.003px，默认的行高是默认字体的1.231倍。对于中文来说，常用的字体大小12px、14px、16px、18px等偶数大小，在IE6和IE7设置其行高也为偶数能解决一些特殊情况下的字体对其问题。

在IE6和IE7中，行高值必须大于字体的2px才能保证字体的完整显示或当其作为链接时能有效显示下划线。

设置line-height时，注意不要使用单位（包括%在内），因为子节点会继承经过运算后的line-height值，所以当使用单位后浏览器会把line-height计算成第一次定义的绝对值，而不会随着字体大小的变化而变化，而无单位的数值表示是所在容器的font-size的倍数，所以设置为无单位的数值是最佳选择。

深入CSS 行高非常有利于理解line-height，值得一读。

性能和效率

大部分平台都有arial，减少浏览器的查找时间。

代码最少，书写方便。arial基本上是名字最短的字体了，可以节约CSS的大小。

所有的字母都小写，目前Google就是这样做的，好处是既可以编写更快也能提升Gzip压缩的效率。

中文最好用unicode表示，比如使用宋体是{font-family:\5b8b\4f53;}，使用微软雅黑是{font-family:\5fae\8f6f\96c5\9ed1;}，这样的好处是避免编码问题，同时能得到所有的主流浏览器的支持。

使用正确的字体种类写法，避免使用引号，这样可以缩小CSS的大小。中文字体可以按上一条方式来编写。

未来

通过对中英文及符号混排的测试，我发现微软雅黑其实表现相当不错，包括英文数字和英文字符以及在IE6和IE7的显示效果上，但唯一的遗憾是在XP下如果安装了微软雅黑字体的用户没有打开“使用屏幕字体的边缘平滑”选项的话，在Firefox、Safari和Opera、特别是IE6下会非常模糊难以辨认。针对这个问题目前并没有很好的解决方案，所以只有等到IE6使用比率非常小的时候才可能正式的使用它。或许需要到2014年，XP死掉的时候。

虽然很早就有了@font-face，但是浏览器的支持、网速和商业问题，导致它很少被应用。最近关于字体的好消息是Firefox3.6将支持Web Open Font Forma。关于Web字体未来的相关信息可以看Web 字体的未来、关于 Web 字体：现状与未来和再谈 Web 字体的现状与未来。

There are a thousand ways to design and create buttons today and you only need to spend a small amount of time looking through work on dribbble to get a sense of them. A great deal of these examples are exactly the same, but occasionally there are the odd few that feel like they’ve had a little more care and attention in their making.

Taking advantage of wonderful new CSS3 properties we can create some amazingly elegant and stylish buttons styles without so much as the whiff of an image and have perfectly adequate fall back styles for older browsers. You may like to create your buttons straight in CSS, or you may like to head for your layout tool of choice, but it’s important to think carefully about how your button design lives in context.

It’s all too easy to simply reach for a pre-designed ‘UI Elements PSD’ that some generous soul has shared for free (and no doubt contains Apple inspired buttons). But why not take a moment to consider whether said button style is appropriate in the context of your design and consider if there’s room to create something a little more original?

Recycling someone else’s buttons is fine, it saves time, but there’s no harm in taking a moment to understand the design and composition of your (or someone else’s) buttons in a little more detail. How are they designed? Do they fit the interface/context/brand? Is there an opportunity to create something unique? Are my buttons prominent enough? Do I need primary, secondary, tertiary buttons? Do they differ substantially enough from each other? Do they look slick?! (Why not, we all want to design cool looking stuff right?!).

Here are ten quick and simple things that I always think about when designing buttons. I’m not going to share ideas on how to use layer effects in Photoshop but some simple, general design principles that can go a long away in optimizing the design of your buttons and other UI in general.

It’s important that your buttons match their contextual style. This could mean fitting in with a color palette, graphical style or taking a lead from some form of brand guidelines or logo. Perhaps there are some prominent shapes, textures or design styles that you can pick up on. Maybe a logo has a circular aspect to it and you could pick up on this in your buttons or other potential calls to action.

If an interface predominately uses flat color then perhaps big shiny Apple-like buttons aren’t the way to go. If you can, take the opportunity to experiment with extending the brand through to the interface by using appropriate shapes, effects, coloring or other forms of embellishment.

Following on from above, stop for a moment before opening the ‘UI Elements PSD’. It’s easy to reach for grads, shadows, bevels etc. but take a moment to think whether it’s the right choice not just to match a brand but also the interface in which the buttons sit and whether they need to feel overly ‘buttony’.

Buttons may need to feel particularly button-like within an app and on mobile, for example, but with websites maybe there’s room to do something a little different with your buttons or calls to action.

With so many interface designs being inspired by Apple OS styling, particularly in a lot of the UI Element PSD’s out there, buttons can get a little lost amongst other elements being used in the UI, diluting their potentially important power. Try using color, size, whitespace or typography to ensure your buttons have the visual weight they need to stand out from the rest of the interface.

Following on from the above, if there are lots of other rounded corner UI elements in your design, consider using circular  ended buttons or perhaps some other change in shape. This could give you an extra bit of contrast that ensures your important calls to action have the prominence they may need.

If you’re striving for an OS inspired style or you’re working with a predesigned elements PSD then it’s likely your UI elements will predominantly be rounded corner rectangular in shape. Consider reducing the level of embellishment on elements that can afford to feel less ‘buttony’.

Most buttons we see out there have some form of border or stroke on them. Loosely speaking, if your button is darker than the background on which it sits use a dark stroke of the general button color. If the reverse is true then go for a stroke that’s a darker shade of the background color. If you stick with the former and use it on a darker background I find it can make the button edges a little ‘dirty’. Using the latter can also help make your button really pop. I consider this to be a general design principle when dealing with strokes/borders in web design.

Over the years I’ve always sworn by my ‘Shadow Law’. The ‘Shadow Law’ states that drop shadows work best when an element is lighter than its background. If an element is darker than its background then drop shadows should be used very subtly. Similar to color matching strokes and borders, I very much consider this to be a general design principle that applies to all UI elements.

As well as being another small detail that can further differentiate your buttons from similar UI elements, the use of simple iconic elements such as arrows can give some sense of action and a small affordance as to what happens when a user clicks.

For example, an arrow pointing right after the text on a button maybe gives the user some sense of moving on or leaving the page. An arrow pointing down might suggest that some content will be progressively disclosed below, or perhaps some kind of menu will open.

If you’re designing an interface where there are consistently lots of actions and functionality on display it may be important to establish some visual language with your buttons by establishing primary, secondary, tertiary and potentially more styles.

Consider reserving the strongest and boldest color for your primary buttons and using progressively less strength or saturation as you reduce importance. As well as color and shade, consider reducing size, whitespace, text size and level of embellishment to further reduce the visual weight of buttons that aren’t primary.

This is a no brainer really, but is often something considered toward the end of the design process. Always work through the core states required for your buttons to ensure they provide the user with sufficient feedback in their context. Users will likely have a mental model of how a button works in the real world as they use it through its various states. Some simple CSS tweaks with shadows, border and gradients and the like can give the user some simple feedback and a touch of eye candy!

As designers you’ll all have your own process you go through. I’ll bet a lot of the time that can involve moving your head back from the screen, tilting it slightly, squinting and saying ‘Yeah that’s about right!’. That’s part of the fun of designing of course and talented designers tend to get it right doing just that, but I think it’s always good to run a bit of internal commentary, interrogating and reasoning over the design decisions you’re making.

There’s no harm in re-using or leaning on pre-designed styles and UI elements, they can obviously save a lot of time. It may even be the case that someone has pixel-perfectly crafted exactly what you were looking for and is offering it for free. However, I don’t think there’s any harm in having a deeper understanding of the design process and craft behind what you’re creating and informing your design decisions going forward.