什么是normalize.css?
它是为了帮助我们统一各个浏览器的样式和消除bug的css库。
为什么需要normalize.css，有什么好处？
- 不像一些reset.css，normalize.css会保持浏览器的默认效果。
- 对大多数的元素进行了合理的限制。
- 修复了bug和一些常见的浏览器的不一致。
- 提高了开发效率。
normalize.css使用情况如何？
github地址：https://github.com/necolas/normalize.css。
从github上我们可以看到，normalize.css已经有2万+的star，足以看到其受欢迎的程度，并且Bootstrap也是使用的normalize.css，所以，放心使用吧！
normalize.css源码解析
/*! normalize.css v7.0.0 | 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
* IE on Windows Phone and in iOS. 一些手机中，在屏幕方向发生变化时会强制改变文字大小，这里做出限制。
*/
html {
line-height: 1.15; /* 1 */
-ms-text-size-adjust: 100%; /* 2 */
-webkit-text-size-adjust: 100%; /* 2 */
}
/* Sections
========================================================================== */
/**
* Remove the margin in all browsers (opinionated). padding都是0，所以只需要限制margin即可。
*/
body {
margin: 0;
}
/**
* Add the correct display in IE 9-. 在IE9以下的浏览器中， 会将不认识的元素（不支持的元素）看做是内联元素，所以这里进行纠正。
*/
article,
aside,
footer,
header,
nav,
section {
display: block;
}
/**
* Correct the font size and margin on `h1` elements within `section` and
* `article` contexts in Chrome, Firefox, and Safari. 对h1做出修正。
*/
h1 {
font-size: 2em;
margin: 0.67em 0;
}
/* Grouping content
========================================================================== */
/**
* Add the correct display in IE 9-.
* 1. Add the correct display in IE.
*/
figcaption,
figure,
main { /* 1 */
display: block;
}
/**
* Add the correct margin in IE 8.
*/
figure {
margin: 1em 40px;
}
/**
* 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
========================================================================== */
/**
* 1. Remove the gray background on active links in IE 10.
* 2. Remove gaps in links underline in iOS 8+ and Safari 8+. 背景色为透明。
*/
a {
background-color: transparent; /* 1 */
-webkit-text-decoration-skip: objects; /* 2 */
}
/**
* 1. Remove the bottom border in Chrome 57- and Firefox 39-.
* 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 */
}
/**
* Prevent the duplicate application of `bolder` by the next rule in Safari 6.
*/
b,
strong {
font-weight: inherit;
}
/**
* 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 style in Android 4.3-.
*/
dfn {
font-style: italic;
}
/**
* Add the correct background and color in IE 9-.
*/
mark {
background-color: #ff0;
color: #000;
}
/**
* Add the correct font size in all browsers. 统一small的字体大小。
*/
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
========================================================================== */
/**
* Add the correct display in IE 9-. IE9以下设置为inline-block，否则有可能宽高出现问题。
*/
audio,
video {
display: inline-block;
}
/**
* Add the correct display in iOS 4-7.
*/
audio:not([controls]) {
display: none;
height: 0;
}
/**
* Remove the border on images inside links in IE 10-. 去除border。
*/
img {
border-style: none;
}
/**
* Hide the overflow in IE.
*/
svg:not(:root) {
overflow: hidden;
}
/* Forms
========================================================================== */
/**
* 1. Change the font styles in all browsers (opinionated).
* 2. Remove the margin in Firefox and Safari.
*/
button,
input,
optgroup,
select,
textarea {
font-family: sans-serif; /* 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;
}
/**
* 1. Prevent a WebKit bug where (2) destroys native `audio` and `video`
* controls in Android 4.
* 2. Correct the inability to style clickable types in iOS and Safari.
*/
button,
html [type="button"], /* 1 */
[type="reset"],
[type="submit"] {
-webkit-appearance: button; /* 2 */
}
/**
* Remove the inner border and padding in Firefox. 去除border
*/
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 */
}
/**
* 1. Add the correct display in IE 9-.
* 2. Add the correct vertical alignment in Chrome, Firefox, and Opera. 修复一些浏览器对于vertical-align的bug
*/
progress {
display: inline-block; /* 1 */
vertical-align: baseline; /* 2 */
}
/**
* Remove the default vertical scrollbar in IE.
*/
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 and cancel buttons in Chrome and Safari on macOS.
*/
[type="search"]::-webkit-search-cancel-button,
[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 IE 9-.
* 1. Add the correct display in Edge, IE, and Firefox. 防止误当做内联元素。
*/
details, /* 1 */
menu {
display: block;
}
/*
* Add the correct display in all browsers.
*/
summary {
display: list-item;
}
/* Scripting
========================================================================== */
/**
* Add the correct display in IE 9-.
*/
canvas {
display: inline-block;
}
/**
* Add the correct display in IE.
*/
template {
display: none;
}
/* Hidden
========================================================================== */
/**
* Add the correct display in IE 10-.
*/
[hidden] {
display: none;
}
尽情使用吧！
时间： 2024-10-12 15:12:03