浅谈nornalize.css(含源码)

/*! normalize.css v6.0.0 | 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. */html { ?line-height: 1.15; /* 1 */ ?-ms-text-size-adjust: 100%; /* 2 */ ?-webkit-text-size-adjust: 100%; /* 2 */}/* Sections ??========================================================================== *//** * Add the correct display in IE 9-. */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. */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+. */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. */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-. */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-. */img { ?border-style: none;}/** * Hide the overflow in IE. */svg:not(:root) { ?overflow: hidden;}/* Forms ??========================================================================== *//** * Remove the margin in Firefox and Safari. */button,input,optgroup,select,textarea { ?margin: 0;}/** * 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;}/** * 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. */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. */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;}