/*! normalize.css v8.0.0 | MIT License | github.com/necolas/normalize.css */

/* Document
   ========================================================================== */

/**
 * 1. 修正所有浏览器中的行高.
 * 2. 在iOS的切换横竖屏时，防止字体大小的调整.
 */

html {
  line-height: 1.15; /* 1 */
  -webkit-text-size-adjust: 100%; /* 2 */
}

/* Sections
   ========================================================================== */

/**
 * 删除所有浏览器的margin值。
 */

body {
  margin: 0;
}

/**
 * Correct the font size and margin on `h1` elements within `section` and
 * `article` contexts in Chrome, Firefox, and Safari.
 * 修正h1元素的font-size和margin值
 */

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.
 * 1.修正火狐浏览器的box-sizing
 */

hr {
  box-sizing: content-box; /* 1 */
  height: 0; /* 1 */
  overflow: visible; /* 2 */
}

/**
 * 1. Correct the inheritance and scaling of font size in all browsers.
 * 1. 在所有浏览器中纠正字体大小的继承和扩展。
 * 2. Correct the odd `em` font sizing in all browsers.
 * 2. 在所有浏览器中纠正奇数的字体大小。
 */

pre {
  font-family: monospace, monospace; /* 1 */
  font-size: 1em; /* 2 */
}

/* Text-level semantics：文本级别的语义
   ========================================================================== */

/**
 * Remove the gray background on active links in IE 10.
 * 删除IE 10中活跃链接的灰色背景。
 */

a {
  background-color: transparent;
}

/**
 * 1. Remove the bottom border in Chrome 57-
 * 1. 移除Chrome 57-浏览器的border-bottom
 * 2. Add the correct text decoration in Chrome, Edge, IE, Opera, and Safari.
 * 2. 在Chrome、Edge、IE、Opera和Safari中添加正确的text-decoration。
 */

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.
 * 在Chrome、Edge和Safari中添加正确的font-weight
 */

b,
strong {
  font-weight: bolder;
}

/**
 * 1. Correct the inheritance and scaling of font size in all browsers.
 * 1.在所有浏览器中纠正字体大小的继承和扩展。
 * 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.
 * 防止“sub”和“sup”元素影响所有浏览器的线高度。
 */

sub,
sup {
  font-size: 75%;
  line-height: 0;
  position: relative;
  vertical-align: baseline;
}

sub {
  bottom: -0.25em;
}

sup {
  top: -0.5em;
}

/* Embedded content：嵌入命令
   ========================================================================== */

/**
 * 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.
 * 在Edge、Firefox和IE中删除文本转换的继承。
 * 1. Remove the inheritance of text transform in Firefox.
 * 1. 删除Firefox中文本转换的继承。
 */

button,
select { /* 1 */
  text-transform: none;
}

/**
 * Correct the inability to style clickable types in iOS and Safari.
 * 纠正在iOS和Safari中无法使用可点击类型的功能。
 */

button,
[type="button"],
[type="reset"],
[type="submit"] {
  -webkit-appearance: button;
}

/**
 * Remove the inner border and padding in Firefox.
 * 移除Firefox中border和padding
 */

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.
 * 恢复以前规则未设置的焦点样式。
 */

button:-moz-focusring,
[type="button"]:-moz-focusring,
[type="reset"]:-moz-focusring,
[type="submit"]:-moz-focusring {
  outline: 1px dotted ButtonText;
}

/**
 * Correct the padding in Firefox.
 * 修正火狐的padding值
 */

fieldset {
  padding: 0.35em 0.75em 0.625em;
}

/**
 * 1. Correct the text wrapping in Edge and IE.
 * 1. 
 * 2. Correct the color inheritance from `fieldset` elements in IE.
 * 2. 从IE的“fieldset”元素中纠正颜色继承。
 * 3. Remove the padding so developers are not caught out when they zero out
 *    `fieldset` elements in all browsers.
 * 3.
 */

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.
 * 在Chrome、Firefox和Opera中添加正确的垂直对齐方式。
 */

progress {
  vertical-align: baseline;
}

/**
 * Remove the default vertical scrollbar in IE 10+.
 * 删除IE 10+中的默认垂直滚动条
 */

textarea {
  overflow: auto;
}

/**
 * 1. Add the correct box sizing in IE 10.
 * 1. 修正IE10中的box-sizing
 * 2. Remove the padding in IE 10.
 * 2. 移除IE10的padding值
 */

[type="checkbox"],
[type="radio"] {
  box-sizing: border-box; /* 1 */
  padding: 0; /* 2 */
}

/**
 * Correct the cursor style of increment and decrement buttons in Chrome.
 * 修正Chrome中增加和减量按钮的光标样式。
 */

[type="number"]::-webkit-inner-spin-button,
[type="number"]::-webkit-outer-spin-button {
  height: auto;
}

/**
 * 1. Correct the odd appearance in Chrome and Safari.
 * 1. 修正在Chrome和Safari中出现的奇怪现象。
 * 2. Correct the outline style in Safari.
 * 2. 修正Safari中的outline样式
 */

[type="search"] {
  -webkit-appearance: textfield; /* 1 */
  outline-offset: -2px; /* 2 */
}

/**
 * Remove the inner padding in Chrome and Safari on macOS.
 * 移除chrome和macos上的Safari的padding值
 */

[type="search"]::-webkit-search-decoration {
  -webkit-appearance: none;
}

/**
 * 1. Correct the inability to style clickable types in iOS and Safari.
 * 1. 纠正在iOS和Safari中无法使用可点击类型的功能。
 * 2. Change font properties to `inherit` in Safari.
 * 2. 在Safari中更改字体属性，以“inherit”。
 */

::-webkit-file-upload-button {
  -webkit-appearance: button; /* 1 */
  font: inherit; /* 2 */
}

/* Interactive：交互式的
   ========================================================================== */

/*
 * Add the correct display in Edge, IE 10+, and Firefox.
 * 修正Edge, IE 10+,和 Firefox中details标签的display属性
 */

details {
  display: block;
}

/*
 * Add the correct display in all browsers.
 * 修正所有浏览器的display属性
 */

summary {
  display: list-item;
}

/* Misc
   ========================================================================== */

/**
 * Add the correct display in IE 10+.
 * 修正IE10+的template元素的display
 */

template {
  display: none;
}

/**
 * Add the correct display in IE 10.
 * 修正IE 10中的display
 */

[hidden] {
  display: none;
}