CSS样式初始化
方法一：css reset
/* reset */
html{color:#000;background:#fff;}
body,div,dl,dt,dd,ul,ol,li,h2,h3,h4,h5,h6,h7,input,button,textarea,p,blockquote,th,td{margin:0;padding:0;}
body{font:12px/1 Tahoma,Helvetica,Arial,"\5b8b\4f53",sans-serif;}
img{border:none;}
em,strong{font-style:normal;font-weight:normal;}
li{list-style:none;}
table {border-collapse:collapse;border-spacing:0;}
h2{font-size:18px;}
h3{font-size:16px;}
h4{font-size:14px;}
h5, h6, h7{font-size:100%;}
q:before,q:after{content:'';}/* 消除q前后的内容 */
button,input,select,textarea{font-size:100%;}/* 使得表单元素在 ie 下能继承字体大小 */
input,button,textarea,select,optgroup,option{font-family:inherit;font-size:inherit;font-style:inherit;font-weight:inherit;}
address,cite,dfn,em,var{font-style:normal;} /* 将斜体扶正 */
/* link */
a{color:#36c;text-decoration:none;}
a:hover{color:#f60;text-decoration:underline;}
方法二：normalize.css
/*! normalize.css v4.1.1 | MIT License | github.com/necolas/normalize.css */
/**
* 1. Change the default font family in all browsers (opinionated).
* 2. Prevent adjustments of font size after orientation changes in IE and iOS.
*/
html {
font-family: sans-serif; /* 1 */
-ms-text-size-adjust: 100%; /* 2 */
-webkit-text-size-adjust: 100%; /* 2 */
}
/**
* Remove the margin in all browsers (opinionated).
*/
body {
margin: 0;
}
/* HTML5 display definitions
========================================================================== */
/**
* Add the correct display in IE 9-.
* 1. Add the correct display in Edge, IE, and Firefox.
* 2. Add the correct display in IE.
*/
article,
aside,
details, /* 1 */
figcaption,
figure,
footer,
header,
main, /* 2 */
menu,
nav,
section,
summary { /* 1 */
display: block;
}
/**
* Add the correct display in IE 9-.
*/
audio,
canvas,
progress,
video {
display: inline-block;
}
/**
* Add the correct display in iOS 4-7.
*/
audio:not([controls]) {
display: none;
height: 0;
}
/**
* Add the correct vertical alignment in Chrome, Firefox, and Opera.
*/
progress {
vertical-align: baseline;
}
/**
* Add the correct display in IE 10-.
* 1. Add the correct display in IE.
*/
template, /* 1 */
[hidden] {
display: none;
}
/* Links
========================================================================== */
/**
* 1. Remove the gray background on active links in IE 10.
* 2. Remove gaps in links underline in iOS 8+ and Safari 8+.
*/
a {
background-color: transparent; /* 1 */
-webkit-text-decoration-skip: objects; /* 2 */
}
/**
* Remove the outline on focused links when they are also active or hovered
* in all browsers (opinionated).
*/
a:active,
a:hover {
outline-width: 0;
}
/* Text-level semantics
========================================================================== */
/**
* 1. Remove the bottom border in 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;
}
/**
* Add the correct font style in Android 4.3-.
*/
dfn {
font-style: italic;
}
/**
* Correct the font size and margin on `h2` elements within `section` and
* `article` contexts in Chrome, Firefox, and Safari.
*/
h2 {
font-size: 2em;
margin: 0.67em 0;
}
/**
* Add the correct background and color in IE 9-.
*/
mark {
background-color: #ff0;
color: #000;
}
/**
* 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 p_w_picpaths inside links in IE 10-.
*/
img {
border-style: none;
}
/**
* Hide the overflow in IE.
*/
svg:not(:root) {
overflow: hidden;
}
/* Grouping content
========================================================================== */
/**
* 1. Correct the inheritance and scaling of font size in all browsers.
* 2. Correct the odd `em` font sizing in all browsers.
*/
code,
kbd,
pre,
samp {
font-family: monospace, monospace; /* 1 */
font-size: 1em; /* 2 */
}
/**
* 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 */
}
/* Forms
========================================================================== */
/**
* 1. Change font properties to `inherit` in all browsers (opinionated).
* 2. Remove the margin in Firefox and Safari.
*/
button,
input,
select,
textarea {
font: inherit; /* 1 */
margin: 0; /* 2 */
}
/**
* Restore the font weight unset by the previous rule.
*/
optgroup {
font-weight: bold;
}
/**
* 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.
*/
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;
}
/**
* Change the border, margin, and padding in all browsers (opinionated).
*/
fieldset {
border: 1px solid #c0c0c0;
margin: 0 2px;
padding: 0.35em 0.625em 0.75em;
}
/**
* 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 */
}
/**
* 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 OS X.
*/
[type="search"]::-webkit-search-cancel-button,
[type="search"]::-webkit-search-decoration {
-webkit-appearance: none;
}
/**
* Correct the text style of placeholders in Chrome, Edge, and Safari.
*/
::-webkit-input-placeholder {
color: inherit;
opacity: 0.54;
}
/**
* 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 */
}