/*! normalize.css v3.0.3 | MIT License | github.com/necolas/normalize.css */
/**
* 1. Set default font family to sans-serif.
* 1. 设置默认字体样式为无衬线字体
* 2. Prevent iOS and IE text size adjust after device orientation change,
* 2. 防止IOS设备和IE下字体大小因为屏幕的转向而改变。
* 附:iOS设备旋转后可能会自动调整字体大小(e.g. 竖着的时候是14px,横着就自动调整成20px)。
* without disabling user zoom.
* 并没有禁用用户放大。
*/
html {
font-family: sans-serif; /* 1 */
-ms-text-size-adjust: 100%; /* 2 */
-webkit-text-size-adjust: 100%; /* 2 */
}
/**
* Remove default margin.
* 移除默认的margin.
*/
body {
margin: 0;
}
/* HTML5 display definitions
========================================================================== */
/**
* Correct `block` display not defined for any HTML5 element in IE 8/9.
* 纠正了HTML5元素的块状属性在IE8/9中无法识别。
* Correct `block` display not defined for `details` or `summary` in IE 10/11
* and Firefox.
*IE10/11及Firefox中details` or `summary无法块状显示
* Correct `block` display not defined for `main` in IE 11.
*在IE11中main不是块状级别。
*/
article,
aside,
details,
figcaption,
figure,
footer,
header,
main,
menu,
nav,
section,
summary {
display: block;
}
/**
* 1. Correct `inline-block` display not defined in IE 8/9.
* 1.补充了HTML5新元素inline-block在IE8/9下的正确显示。
* 2. Normalize vertical alignment of `progress` in Chrome, Firefox, and Opera.
* 2.补充了部分HTML5新元素在浏览器下的垂直对齐方式为基线对齐(vertical-align: baseline)
*/
audio,
canvas,
progress,
video {
display: inline-block; /* 1 */
vertical-align: baseline; /* 2 */
}
/**
* Prevent displaying `audio` without controls in Mobile Safari 4/5/6/7.
*如果audio标签没有控制栏,则应该隐藏
*/
audio:not([controls]) {
display: none;
height: 0;
}
/**
* Address `[hidden]` styling not present in IE 8/9/10.
* Hide the `template` element in IE 8/9/10/11, Safari, and Firefox < 22.
* 新的template标签用于HTML模板,兼容旧浏览器,隐藏模板。
*/
[hidden],
template {
display: none;
}
/* Links
========================================================================== */
/**
* Remove the gray background color from active links in IE 10.
* 移除在IE10下点击超链接出现的背景。
*/
a {
background-color: transparent;
}
/**
* Improve readability of focused elements when they are also in an
* active/hover state.
*/
a:active,
a:hover {
outline: 0;
}
/* Text-level semantics
/**
*
*语义化文本标签
*/
/*
========================================================================== */
/**
* Address inconsistent styling of `abbr[title]`.
* 1. Correct styling in Firefox 39 and Opera 12.
* 2. Correct missing styling in Chrome, Edge, IE, Opera, and Safari.
*/
abbr[title] {
border-bottom: none; /* 1 */
text-decoration: underline; /* 2 */
text-decoration: underline dotted; /* 2 */
}
/**
* Address inconsistent styling of b and strong.
* 1. Correct duplicate application of `bolder` in Safari 6.0.2.
* 2. Correct style set to `bold` in Edge 12+, Safari 6.2+, and Chrome 18+.
*/
/**
*统一了b,strong样式格式:
*1.abbr元素在firefox外其他的浏览器下没有下划线的问题
*2.统一了Safari and Chrome 给b 和strong设置的属性是bolder
*/
b,
strong {
font-weight: inherit; /* 1 */
}
b,
strong {
font-weight: bolder; /* 2 */
}
/**
* Address styling not present in Safari and Chrome.
*/
/**
*dfn用于对特殊术语和专业短语的定义,在safari和chrome中不是斜体
*
*/
dfn {
font-style: italic;
}
/**
* Address variable `h1` font-size and margin within `section` and `article`
* contexts in Firefox 4+, Safari, and Chrome.
*/
/**
*在section和article中h1标签的字体大小、margin样式不统一
*
*/
h1 {
font-size: 2em;
margin: 0.67em 0;
}
/**
* Address styling not present in IE 8/9.
*/
/**
*mark标签用来突出显示标记的文本,背后有一个高亮的背景色,低版本中并不识别。
*
*/
mark {
background-color: #ff0;
color: #000;
}
/**
* Address inconsistent and variable font size in all browsers.
*/
/**
*统一了small标签在所有浏览器中的样式
*
*/
small {
font-size: 80%;
}
/**
* Prevent `sub` and `sup` affecting `line-height` in all browsers.
*/
/**
*sub和sup表示上标和下表,统一两者的样式。
*
*/
sub,
sup {
font-size: 75%;
line-height: 0;
position: relative;
vertical-align: baseline;
}
sup {
top: -0.5em;
}
sub {
bottom: -0.25em;
}
/* Embedded content
========================================================================== */
/**
* Remove border when inside `a` element in IE 8/9/10.
*/
/**
* 移除了在IE 8/9/10下a标签img的边框(旧版本的IE浏览器下有蓝色边框)
*/
img {
border: 0;
}
/**
* Correct overflow not hidden in IE 9/10/11.
*/
/**
* 图片多余部分在IE 9/10/11下不隐藏的问题
*/
svg:not(:root) {
overflow: hidden;
}
/* Grouping content群组元素
========================================================================== */
/**
* 修复margin不起作用问题
*/
figure {
margin: 1em 40px;
}
/**
* Address inconsistent styling of `hr`.
* 1. Correct `box-sizing` set to `border-box` in Firefox.
* 2. Correct `overflow` set to `hidden` in IE 8/9/10/11 and Edge 12.
*/
/**
* 统一了hr样式.
* 1. 在Firefox下设置了box-sizing`为border-box
* 2. 修正在IE 8/9/10/11 and Edge 12下overflow值为visible
*/
hr {
box-sizing: content-box; /* 1 */
height: 0; /* 1 */
overflow: visible; /* 2 */
}
/**
* Contain overflow in all browsers.
*/
/**
* 原先标签多出的直接溢出,这里标签溢出增加滚动条.
*/
pre {
overflow: auto;
}
/**
* 1. Correct inheritance and scaling of font-size for preformatted text.
* 2. Address odd `em`-unit font size rendering in all browsers.
*/
/**
* 统一了在各个浏览器中字体样式
*
*/
code,
kbd,
pre,
samp {
font-family: monospace, monospace; /* 1 */
font-size: 1em; /* 2 */
}
/* Forms表单
========================================================================== */
/**
* Known limitation: by default, Chrome and Safari on OS X allow very limited
* styling of `select`, unless a `border` property is set.
*/
/**
* 1. Correct font properties not being inherited.
* 2. Address margins set differently in Firefox 4+, Safari, and Chrome.
*/
/**
* 纠正了表单标签字体不继承的问题。
* 在各个浏览器中外边距不统一
*/
button,
input,
optgroup,
select,
textarea {
font: inherit; /* 1 */
margin: 0; /* 2 */
}
/**
* Address `overflow` set to `hidden` in IE 8/9/10/11.
*/
/**
* 将button便签在IE 8/9/10/11溢出属性改为visible
*/
button {
overflow: visible;
}
/**
* Address inconsistent `text-transform` inheritance for `button` and `select`.
* All other form control elements do not inherit `text-transform` values.
* Correct `button` style inheritance in Firefox, IE 8/9/10/11, and Opera.
* Correct `select` style inheritance in Firefox.
*/
/**
* 纠正了button、select标签text-transform属性继承的问题。
*
*/
button,
select {
text-transform: none;
}
/**
* 1. Avoid the WebKit bug in Android 4.0.* where (2) destroys native `audio`
* and `video` controls.
* 2. Correct inability to style clickable `input` types in iOS.
* 3. Improve usability and consistency of cursor style between image-type
* `input` and others.
*/
/**
* 1. 避免Android 4.0.*中的WebKit bug破坏原生的audio和video控制器.
* 2. 无法设置可点击的input标签问题
* 3. 统一其他类型的input光标样式
*
*/
button,
html input[type=”button”], /* 1 */
input[type=”reset”],
input[type=”submit”] {
-webkit-appearance: button; /* 2 */
cursor: pointer; /* 3 */
}
/**
* 统一按钮禁用时的鼠标光标样式
*/
button[disabled],
html input[disabled] {
cursor: default;
}
/**
* 移除Firefox 4+下的边框和内边距.
*/
button::-moz-focus-inner,
input::-moz-focus-inner {
border: 0;
padding: 0;
}
/**
* Restore focus style in Firefox 4+ (unset by a rule above)
*/
button:-moz-focusring,
input:-moz-focusring {
outline: 1px dotted ButtonText;
}
/**
* 修复了Firefox 4+中设置`line-height`为normal!important样式。
*
*/
input {
line-height: normal;
}
/**
* It’s recommended that you don’t attempt to style these elements.
* Firefox’s implementation doesn’t respect box-sizing, padding, or width.
*
* 1. Address box sizing set to `content-box` in IE 8/9/10.
* 2. Remove excess padding in IE 8/9/10.
*/
/**
* 1. 修正checkbox、radio在IE 8/9/10下box sizing设置为content-box的问题
* 2. 移除checkbox、radio在IE 8/9/10中多余的内边距
*/
input[type=”checkbox”],
input[type=”radio”] {
box-sizing: border-box; /* 1 */
padding: 0; /* 2 */
}
/**
* Fix the cursor style for Chrome’s increment/decrement buttons. For certain
* `font-size` values of the `input`, it causes the cursor style of the
* decrement button to change from `default` to `text`.
*/
/*修正input[type=”number”]光标改变效果*/
input[type=”number”]::-webkit-inner-spin-button,
input[type=”number”]::-webkit-outer-spin-button {
height: auto;
}
/**
* Address `appearance` set to `searchfield` in Safari and Chrome.
*/
/*修正在chrome下input[type=”search”]appearance值设置为searchfield*/
input[type=”search”] {
-webkit-appearance: textfield;
}
/**
* Remove inner padding and search cancel button in Safari and Chrome on OS X.
* Safari (but not Chrome) clips the cancel button when the search input has
* padding (and `textfield` appearance).
*/
/**
* 统一输入框的样式,移除了默认的一些样式。
*/
input[type=”search”]::-webkit-search-cancel-button,
input[type=”search”]::-webkit-search-decoration {
-webkit-appearance: none;
}
/**
* 统一了fieldset的border、外边距和内边距
*/
fieldset {
border: 1px solid #c0c0c0;
margin: 0 2px;
padding: 0.35em 0.625em 0.75em;
}
/**
* 1. Correct `color` not being inherited in IE 8/9/10/11.
* 2. Remove padding so people aren’t caught out if they zero out fieldsets.
*/
/**
* 1. 在 IE 8/9/10/11下颜色不继承问题
* 2. 重置了内边距
*/
legend {
border: 0; /* 1 */
padding: 0; /* 2 */
}
/**
* Remove default vertical scrollbar in IE 8/9/10/11.
*/
/**
* 移除了textarea在IE 8/9/10/11下的滚动条
*/
textarea {
overflow: auto;
}
/**
* Restore font weight (unset by a rule above).
* NOTE: the default cannot safely be changed in Chrome and Safari on OS X.
*/
/**
* 统一了optgroup标签的font-weight属性为bold
*
*/
optgroup {
font-weight: bold;
}