/*! normalize.css v8.0.1 | 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 iOS.
 */

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

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

/**
 * Remove the margin in all browsers.
 */

body {
  margin: 0;
}

/**
 * Render the `main` element consistently in IE.
 */

main {
  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
   ========================================================================== */

/**
 * 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
   ========================================================================== */

/**
 * Remove the gray background on active links in IE 10.
 */

a {
  background-color: transparent;
}

/**
 * 1. Remove the bottom border in Chrome 57-
 * 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 */
}

/**
 * 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 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 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.
 * 1. Remove the inheritance of text transform in Firefox.
 */

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

/**
 * Correct the inability to style clickable types in iOS and Safari.
 */

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

/**
 * 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;
}

/**
 * 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 */
}

/**
 * Add the correct vertical alignment in Chrome, Firefox, and Opera.
 */

progress {
  vertical-align: baseline;
}

/**
 * Remove the default vertical scrollbar in IE 10+.
 */

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 in Chrome and Safari on macOS.
 */

[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 Edge, IE 10+, and Firefox.
 */

details {
  display: block;
}

/*
 * Add the correct display in all browsers.
 */

summary {
  display: list-item;
}

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

/**
 * Add the correct display in IE 10+.
 */

template {
  display: none;
}

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

[hidden] {
  display: none;
}

/* flex弹性盒布局兼容性写法样式文件
 * 常用类
 * display__flex
 * flex_direction__column
 * flex_wrap__wrap
 * justify_content__center
 * justify_content__space_between
 * justify_content__space_around
 * align_items__center
 * flex_grow__1
 * flex_shrink__0
*/

/*
    设置在弹性容器上的属性
*/
.display__flex {
  display: -webkit-box;
  display: -ms-flexbox;
  display: flex;
}

/*flex-direction属性决定主轴的方向（即项目的排列方向）。*/
.flex_direction__row_reverse {
  -webkit-box-orient: horizontal;
  -webkit-box-direction: reverse;
  -ms-flex-direction: row-reverse;
  flex-direction: row-reverse;
}
.flex_direction__column {
  -webkit-box-orient: vertical;
  -webkit-box-direction: normal;
  -ms-flex-direction: column;
  flex-direction: column;
}
.flex_direction__column_reverse {
  -webkit-box-orient: vertical;
  -webkit-box-direction: reverse;
  -ms-flex-direction: column-reverse;
  flex-direction: column-reverse;
}

/*默认情况下，项目都排在一条线（又称"轴线"）上。flex-wrap属性定义，如果一条轴线排不下，如何换行。*/
.flex_wrap__nowrap {
  -ms-flex-wrap: nowrap;
  flex-wrap: nowrap;
}
.flex_wrap__wrap {
  -ms-flex-wrap: wrap;
  flex-wrap: wrap;
}
.flex_wrap__wrap_reverse {
  -ms-flex-wrap: wrap-reverse;
  flex-wrap: wrap-reverse;
}

/*justify-content属性定义了项目在主轴上的对齐方式。*/
.justify_content__flex_start {
  -webkit-box-pack: start;
  -ms-flex-pack: start;
  justify-content: flex-start;
}
.justify_content__flex_end {
  -webkit-box-pack: end;
  -ms-flex-pack: end;
  justify-content: flex-end;
}
.justify_content__center {
  -webkit-box-pack: center;
  -ms-flex-pack: center;
  justify-content: center;
}
.justify_content__space_between {
  -webkit-box-pack: justify;
  -ms-flex-pack: justify;
  justify-content: space-between;
}
.justify_content__space_around {
  -ms-flex-pack: distribute;
  justify-content: space-around;
}

/*align-items属性定义项目在交叉轴上如何对齐。*/
.align_items__flex_start {
  -webkit-box-align: start;
  -ms-flex-align: start;
  align-items: flex-start;
}
.align_items__flex_end {
  -webkit-box-align: end;
  -ms-flex-align: end;
  align-items: flex-end;
}
.align_items__center {
  -webkit-box-align: center;
  -ms-flex-align: center;
  align-items: center;
}
.align_items__baseline {
  -webkit-box-align: baseline;
  -ms-flex-align: baseline;
  align-items: baseline;
}

/*align-content属性定义了多根轴线的对齐方式。如果项目只有一根轴线，该属性不起作用。*/
.align_content__flex_start {
  -ms-flex-line-pack: start;
  align-content: flex-start;
}
.align_content__flex_end {
  -ms-flex-line-pack: end;
  align-content: flex-end;
}
.align_content__center {
  -ms-flex-line-pack: center;
  align-content: center;
}
.align_content__space_between {
  -ms-flex-line-pack: justify;
  align-content: space-between;
}
.align_content__space_around {
  -ms-flex-line-pack: distribute;
  align-content: space-around;
}

/*
  设置在弹性项目上的属性
*/

/*order属性定义项目的排列顺序。数值越小，排列越靠前，默认为0。以下是兼容样式写法示例，可根据需要修改属性值。*/
.order__1 {
  -webkit-box-ordinal-group: 2;
  -ms-flex-order: 1;
  order: 1;
}

/*flex-grow属性定义项目的放大比例，默认为0，即如果存在剩余空间，也不放大。以下是兼容样式写法示例，可根据需要修改属性值。*/
.flex_grow__1 {
  -webkit-box-flex: 1;
  -ms-flex-positive: 1;
  flex-grow: 1;
}

/*flex-shrink属性定义了项目的缩小比例，默认为1，即如果空间不足，该项目将缩小。以下是兼容样式写法示例，可根据需要修改属性值。*/
.flex_shrink__0 {
  -ms-flex-negative: 0;
  flex-shrink: 0;
}

/*
  flex-basis属性定义了在分配多余空间之前，项目占据的主轴空间（main size）。浏览器根据这个属性，计算主轴是否有多余空间。它的默认值为auto，即项目的本来大小。
  以下是兼容样式写法示例，可根据需要修改属性值。
*/
.flex_basis__100px {
  -ms-flex-preferred-size: 100px;
  flex-basis: 100px;
}

/*align-self属性允许单个项目有与其他项目不一样的对齐方式，可覆盖align-items属性。默认值为auto，表示继承父元素的align-items属性，如果没有父元素，则等同于stretch。*/
.align_self__flex_start {
  -ms-flex-item-align: start;
  align-self: flex-start;
}
.align_self__flex_end {
  -ms-flex-item-align: end;
  align-self: flex-end;
}
.align_self__center {
  -ms-flex-item-align: center;
  align-self: center;
}
.align_self__baseline {
  -ms-flex-item-align: baseline;
  align-self: baseline;
}