目录
基础样式
整个页面的通用规则
normalize.css库可以帮助消除不同客户端浏览器渲染上的不同。
访问：https://necolas.github.io/normalize.css/8.0.1/normalize.css
我也将源码列在文章末尾
修饰符
message模块的变体
message–error
message-warning
不需要定义整个模块，只需要覆盖需要改变的地方
多元素模块
media__image、media__body一起填满media容器，构成media模块
状态类
is-或者has-开头，在JavaScript里面可以动态的添加或者移除它，来达到状态变化
工具类
文字居中、左浮动、清除浮动、隐藏某个元素
.text-center {
text-align: center !important;
}
.float-left {
float: left;
}
.clearfix::before,
.clearfix::after {
content: " ";
display: table;
}
.clearfix::after {
clear: both;
}
.hidden {
display: none !important;
}
模块化CSS理论
样式系统划分为五个具体类别
基础：如果不添加 CSS 类名，标记会以什么外观呈现。
布局：把页面分成一些区域。
模块：设计中的模块化、可复用的单元。
状态：描述在特定的状态或情况下，模块或布局的显示方式。
主题：一个可选的视觉外观层，可以让你更换不同主题
分离容器和内容
区分布局与组件的角色和职责
在标记上使用单一、扁平的选择器
使用其他原则，比如单一职责原则、单一样式来源、内容修饰符
OOCSS【Object-Oriented CSS】
面向对象的 CSS，创建一个 HTML 切换。
<div class="toggle simple">
<div class="toggle-control open">
<h1 class="toggle-title">Title 1</h1>
</div>
<div class="toggle-details open"> ... </div>
...
</div>
两个主要的原则：
分离结构和外观open、simple
分离容器和内容toggle-control、toggle
SMACSS【Scalable and Modular Architecture for CSS】
模块化架构的可扩展 CSS）方法，写出来的代码如下：
<div class="toggle toggle-simple">
<div class="toggle-control is-active">
<h2 class="toggle-title">Title 1</h2>
</div>
<div class="toggle-details is-active">
...
</div>
...
</dl>
normalize.css库
/*! normalize.css v8.0.1 | MIT License | github.com/necolas/normalize.css */
/* Document
========================================================================== */
/**
* 1. Correct the line height in all browsers.
* 2. Prevent adjustments of font size after orientation changes in iOS.
*/
html {
line-height: 1.15; /* 1 */
-webkit-text-size-adjust: 100%; /* 2 */
}
/* Sections
========================================================================== */
/**
* Remove the margin in all browsers.
*/
body {
margin: 0;
}
/**
* Render the `main` element consistently in IE.
*/
main {
display: block;
}
/**
* Correct the font size and margin on `h1` elements within `section` and
* `article` contexts in Chrome, Firefox, and Safari.
*/
h1 {
font-size: 2em;
margin: 0.67em 0;
}
/* Grouping content
========================================================================== */
/**
* 1. Add the correct box sizing in Firefox.
* 2. Show the overflow in Edge and IE.
*/
hr {
box-sizing: content-box; /* 1 */
height: 0; /* 1 */
overflow: visible; /* 2 */
}
/**
* 1. Correct the inheritance and scaling of font size in all browsers.
* 2. Correct the odd `em` font sizing in all browsers.
*/
pre {
font-family: monospace, monospace; /* 1 */
font-size: 1em; /* 2 */
}
/* Text-level semantics
========================================================================== */
/**
* Remove the gray background on active links in IE 10.
*/
a {
background-color: transparent;
}
/**
* 1. Remove the bottom border in Chrome 57-
* 2. Add the correct text decoration in Chrome, Edge, IE, Opera, and Safari.
*/
abbr[title] {
border-bottom: none; /* 1 */
text-decoration: underline; /* 2 */
text-decoration: underline dotted; /* 2 */
}
/**
* Add the correct font weight in Chrome, Edge, and Safari.
*/
b,
strong {
font-weight: bolder;
}
/**
* 1. Correct the inheritance and scaling of font size in all browsers.
* 2. Correct the odd `em` font sizing in all browsers.
*/
code,
kbd,
samp {
font-family: monospace, monospace; /* 1 */
font-size: 1em; /* 2 */
}
/**
* Add the correct font size in all browsers.
*/
small {
font-size: 80%;
}
/**
* Prevent `sub` and `sup` elements from affecting the line height in
* all browsers.
*/
sub,
sup {
font-size: 75%;
line-height: 0;
position: relative;
vertical-align: baseline;
}
sub {
bottom: -0.25em;
}
sup {
top: -0.5em;
}
/* Embedded content
========================================================================== */
/**
* Remove the border on images inside links in IE 10.
*/
img {
border-style: none;
}
/* Forms
========================================================================== */
/**
* 1. Change the font styles in all browsers.
* 2. Remove the margin in Firefox and Safari.
*/
button,
input,
optgroup,
select,
textarea {
font-family: inherit; /* 1 */
font-size: 100%; /* 1 */
line-height: 1.15; /* 1 */
margin: 0; /* 2 */
}
/**
* Show the overflow in IE.
* 1. Show the overflow in Edge.
*/
button,
input { /* 1 */
overflow: visible;
}
/**
* Remove the inheritance of text transform in Edge, Firefox, and IE.
* 1. Remove the inheritance of text transform in Firefox.
*/
button,
select { /* 1 */
text-transform: none;
}
/**
* Correct the inability to style clickable types in iOS and Safari.
*/
button,
[type="button"],
[type="reset"],
[type="submit"] {
-webkit-appearance: button;
}
/**
* Remove the inner border and padding in Firefox.
*/
button::-moz-focus-inner,
[type="button"]::-moz-focus-inner,
[type="reset"]::-moz-focus-inner,
[type="submit"]::-moz-focus-inner {
border-style: none;
padding: 0;
}
/**
* Restore the focus styles unset by the previous rule.
*/
button:-moz-focusring,
[type="button"]:-moz-focusring,
[type="reset"]:-moz-focusring,
[type="submit"]:-moz-focusring {
outline: 1px dotted ButtonText;
}
/**
* Correct the padding in Firefox.
*/
fieldset {
padding: 0.35em 0.75em 0.625em;
}
/**
* 1. Correct the text wrapping in Edge and IE.
* 2. Correct the color inheritance from `fieldset` elements in IE.
* 3. Remove the padding so developers are not caught out when they zero out
* `fieldset` elements in all browsers.
*/
legend {
box-sizing: border-box; /* 1 */
color: inherit; /* 2 */
display: table; /* 1 */
max-width: 100%; /* 1 */
padding: 0; /* 3 */
white-space: normal; /* 1 */
}
/**
* Add the correct vertical alignment in Chrome, Firefox, and Opera.
*/
progress {
vertical-align: baseline;
}
/**
* Remove the default vertical scrollbar in IE 10+.
*/
textarea {
overflow: auto;
}
/**
* 1. Add the correct box sizing in IE 10.
* 2. Remove the padding in IE 10.
*/
[type="checkbox"],
[type="radio"] {
box-sizing: border-box; /* 1 */
padding: 0; /* 2 */
}
/**
* Correct the cursor style of increment and decrement buttons in Chrome.
*/
[type="number"]::-webkit-inner-spin-button,
[type="number"]::-webkit-outer-spin-button {
height: auto;
}
/**
* 1. Correct the odd appearance in Chrome and Safari.
* 2. Correct the outline style in Safari.
*/
[type="search"] {
-webkit-appearance: textfield; /* 1 */
outline-offset: -2px; /* 2 */
}
/**
* Remove the inner padding in Chrome and Safari on macOS.
*/
[type="search"]::-webkit-search-decoration {
-webkit-appearance: none;
}
/**
* 1. Correct the inability to style clickable types in iOS and Safari.
* 2. Change font properties to `inherit` in Safari.
*/
::-webkit-file-upload-button {
-webkit-appearance: button; /* 1 */
font: inherit; /* 2 */
}
/* Interactive
========================================================================== */
/*
* Add the correct display in Edge, IE 10+, and Firefox.
*/
details {
display: block;
}
/*
* Add the correct display in all browsers.
*/
summary {
display: list-item;
}
/* Misc
========================================================================== */
/**
* Add the correct display in IE 10+.
*/
template {
display: none;
}
/**
* Add the correct display in IE 10.
*/
[hidden] {
display: none;
}