article,aside,details,figcaption,figure,footer,header,hgroup,main,nav,section,summary{display:block}audio,canvas,video{display:inline-block}audio:not([controls]){display:none;height:0}[hidden]{display:none}html{font-family:sans-serif;-webkit-text-size-adjust:100%;-ms-text-size-adjust:100%}body{margin:0}a:focus{outline:thin dotted}a:active,a:hover{outline:0}h1{margin:.67em 0}h1,h2,h3,h4,h5,h6{font-size:18px}abbr[title]{border-bottom:1px dotted}b,strong{font-weight:bold}dfn{font-style:italic}hr{-moz-box-sizing:content-box;box-sizing:content-box;height:0}mark{background:#ff0;color:#000}code,kbd,pre,samp{font-family:monospace,serif;font-size:1em}pre{white-space:pre-wrap}q{quotes:"\201C" "\201D" "\2018" "\2019"}small{font-size:80%}sub,sup{font-size:75%;line-height:0;position:relative;vertical-align:baseline}sup{top:-0.5em}sub{bottom:-0.25em}img{border:0}svg:not(:root){overflow:hidden}figure{margin:0}fieldset{border:1px solid #c0c0c0;margin:0 2px;padding:.35em .625em .75em}legend{border:0;padding:0}button,input,select,textarea{font-family:inherit;font-size:100%;margin:0}button,input{line-height:normal}button,select{text-transform:none}button,html input[type="button"],input[type="reset"],input[type="submit"]{-webkit-appearance:button;cursor:pointer}button[disabled],html input[disabled]{cursor:default}input[type="checkbox"],input[type="radio"]{box-sizing:border-box;padding:0}input[type="search"]{-webkit-appearance:textfield;-moz-box-sizing:content-box;-webkit-box-sizing:content-box;box-sizing:content-box}input[type="search"]::-webkit-search-cancel-button,input[type="search"]::-webkit-search-decoration{-webkit-appearance:none}button::-moz-focus-inner,input::-moz-focus-inner{border:0;padding:0}textarea{overflow:auto;vertical-align:top}table{border-collapse:collapse;border-spacing:0}
.sprite-ico-Header_Logo2x,
.sprite-ico-Button_iPhone2x,
.sprite-ico-Button_Android2x,
.sprite-ico-Arrow_Right2x,
.sprite-ico-News_Arrow2x,
.sprite-ico-Dark_News_Arrow2x{background-image:url("share-icons.png");background-repeat:no-repeat;display: inline-block;vertical-align: middle;}.sprite-ico-Header_Logo2x{background-position:0px 0px;width:53px;height:55px;}
.sprite-ico-Button_iPhone2x{background-position:-53px 0px;width:17px;height:20px;}
.sprite-ico-Button_Android2x{background-position:-53px -20px;width:17px;height:20px;}
.sprite-ico-Arrow_Right2x{background-position:-70px 0px;width:12px;height:20px;}
.sprite-ico-News_Arrow2x{background-position:-70px -20px;width:10px;height:15px;}
.sprite-ico-Dark_News_Arrow2x{background-position:-70px -35px;width:10px;height:15px;}
@media only screen and (-webkit-min-device-pixel-ratio: 2.0), only screen and (min--moz-device-pixel-ratio: 2.0), only screen and (-o-min-device-pixel-ratio: 200/100), only screen and (min-device-pixel-ratio: 2.0) {.sprite-ico-Header_Logo2x,
.sprite-ico-Button_iPhone2x,
.sprite-ico-Button_Android2x,
.sprite-ico-Arrow_Right2x,
.sprite-ico-News_Arrow2x,
.sprite-ico-Dark_News_Arrow2x{background-image:url("share-icons@2x.png");-webkit-background-size: 82px 55px;-moz-background-size: 82px 55px;background-size: 82px 55px;}}
body {
    background: #f6f6f6;
    padding-top: 60px;
    font-family: 'Helvetica Neue',Helvetica,Arial,Sans-serif;
}
img {
  vertical-align: middle;
  color: transparent;
  font-size: 0;
}
blockquote {
  border-left: 3px solid #D0E5F2;
  font-style: normal;
  padding: 0 0 0 .5em;
  margin: .5em 0;
  display: block;
  line-height: 1.7em;
  vertical-align:baseline;
  font-size: 100%;
}
ul, ol {
  padding-left: 20px;
}
.web-logo {
  width: 126px;
  height: 42px;
  background-image:url("Web_Logo.png");
  background-repeat:no-repeat;
  display: inline-block;
  vertical-align: middle;
}
.global-header {
  width: 100%;
  position: fixed;
  top:0;
  z-index: 9990;
  height: 60px;
  background-color: #009dd7;
  color: #FaFcFe;
}

.global-header .title {
  font-size: 24px;
  font-weight: 100;
  margin: 0 0 0 63px;
}
.global-header .main-wrap{
  height: 60px;
  position: relative;
  line-height: 60px;
}

.download-banner-v2 {
  position: fixed;
  bottom: 0;
  z-index: 3;
  display: none;
  width: 100%;
  height: 60px;
  background-color: rgba(0, 0, 0, .7);
  color: #fff;
  -webkit-transition: opacity .3s ease-out;
          transition: opacity .3s ease-out;
}

.download-banner-v2.hide {
  opacity: 0;
}

.download-banner-v2 .close {
  position: absolute;
  top: 0;
  left: 0;
  width: 21px;
  height: 21px;
  padding: 19px 12px 20px;
  background-image: url("close.png");
  background-position: center;
  background-repeat: no-repeat;
  background-size: 21px;
  opacity: 1;
}

.download-banner-v2 .icon {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 46px;
  width: 41px;
  height: 41px;
  margin: auto;
  background-image: url("app-icon.png");
  background-position: center;
  background-size: 41px;
}

.download-banner-v2 .title,
.download-banner-v2 .describe {
  margin-left: 97px;
  margin-right: 84px;
  line-height: 1;
}

.download-banner-v2 .title {
  margin-top: 12px;
  margin-bottom: 0;
  font-size: 19px;
}

.download-banner-v2 .describe {
  margin-top: 4px;
  font-size: 12px;
}

.download-banner-v2 .download-btn {
  position: absolute;
  top: 0;
  right: 10px;
  bottom: 0;
  width: 74px;
  height: 23px;
  padding-top: 10px;
  margin: auto;
  font-size: 13px;
  line-height: 1;
  text-align: center;
  text-decoration: none;
  color: #fff;
  background-color: #58af08;
  border: 0;
  border-radius: 4px;
}

.sprite-ico-Header_Logo2x {
  position: absolute;
  bottom: 0;
}

.button {
  display: inline-block;
  height: 36px;
  line-height: 36px;
  width: 120px;
  background-color: #1cade9;
  margin: 0 5px;
  color: white;
  text-decoration: none;
  text-align: center;
  border-radius: 4px;
  font-size: 14px;
}
html.no-touch .button:hover {
  background-color: #1fb3f0;
}
.button i {
  margin-right: 10px;
}
.button span {
  vertical-align: -2px;
}

.download {
  float: right;
}

.main-wrap {
  max-width: 600px;
  min-width: 300px;
  margin: 0 auto;
}

.content-wrap {
  overflow: hidden;
  background-color: #fff;
}
.content-wrap a {
  word-break: break-all;
}

.headline {
  border-bottom: 4px solid #f6f6f6;
}
.headline-title.onlyheading {
  margin: 20px 0;
}
.headline img {
  max-width: 100%;
  vertical-align: top;
}
html.no-touch .headline-background:hover {
  background-color: #fdfdfd;
}
.headline-background-link {
  line-height: 2em;
  position: relative;
  padding: 25px 40px;
  display: block;
  text-decoration: none;
}
.icon-arrow-right {
  position: absolute;
  top:50%;
  right:20px;
  margin-top: -10px;
}
.headline-background .heading{
  color: #999;
  font-size: 20px;
  margin-bottom: 5px;
}
.headline-background .heading-content {
  font-size: 24px;
  color: #444;
  text-decoration: none;
}
.img-wrap {
  position: relative;
  max-height: 375px;
  overflow: hidden;
}
.img-wrap img {
  margin-top: -18%;
  width: 640px;
}
.img-wrap .img-source {
  position: absolute;
  bottom: 10px;
  z-index: 1;
  font-size: 12px;
  color: rgba(255,255,255,.6);
  right: 40px;
  text-shadow: 0px 1px 2px rgba(0,0,0,.3);
}

.logo-image-place-holder {
  background-color: #00addf;
  height: 126px;
}

.logo-image-place-holder img {
  display: block;
  margin: 0 auto;
}

.img-mask {
  position: absolute;
  top:0;
  width: 100%;
  height: 100%;
  background: -moz-linear-gradient(top, rgba(0,0,0,0) 25%, rgba(0,0,0,0.6) 100%); 
  background: -webkit-gradient(linear, left top, left bottom, color-stop(25%,rgba(0,0,0,0)), color-stop(100%,rgba(0,0,0,0.6))); 
  background: -webkit-linear-gradient(top, rgba(0,0,0,0) 25%,rgba(0,0,0,0.6) 100%); 
  background: -o-linear-gradient(top, rgba(0,0,0,0) 25%,rgba(0,0,0,0.6) 100%); 
  background: -ms-linear-gradient(top, rgba(0,0,0,0) 25%,rgba(0,0,0,0.6) 100%); 
  background: linear-gradient(to bottom, rgba(0,0,0,0) 25%,rgba(0,0,0,0.6) 100%); 
  filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#00000000', endColorstr='#99000000',GradientType=0 ); 
}
.headline-title {
  margin: 20px 0 10px;
  font-size: 30px;
  line-height: 1.2em;
  padding: 0 40px;
  color: #222;
}
.img-wrap .headline-title {
  margin: 20px 0;
  bottom: 10px;
  z-index: 1;
  position: absolute;
  color: white;
  text-shadow: 0px 1px 2px rgba(0,0,0,0.3);
}
.headline-summary {
  padding: 20px 40px 0;
}

.meta {
  white-space: nowrap;
  text-overflow: ellipsis;
  overflow: hidden;
  font-size: 16px;
  color: #b8b8b8;
}
.meta span {
  vertical-align: middle;
}
.meta .source-icon {
  width: 20px;
  height: 20px;
}
.meta .time {
  float: right;
  margin-top: 2px;
}
.meta .source-icon {
  margin-right: 4px;
}
.meta .source {
  vertical-align: middle;
}

.content {
  color: #444;
  line-height: 2em;
  margin: 10px 0 25px;
}
.content img{
  max-width: 100%;
  margin: 10px 0;
  display: block;
}
.content img[src*="zhihu.com/equation"] {
display: inline-block;
margin: 0 3px;
}
.content a {
  color: #105CB6;
  text-decoration: none;
}
.content a:hover {
  text-decoration: underline;
}
.view-more {
  text-align: right;
  margin-bottom: 34px;
}
.view-more a{
  color: #698ebf;
  font-size: 14px;
  text-decoration: none;
}
html.no-touch .view-more a:hover {
  text-decoration: underline;
}

.question {
  padding: 0 40px;
  overflow: hidden;
}
.question + .question {
  border-top: 5px solid #f6f6f6;
}

.question-title{
  font-size: 22px;
  line-height: 1.4em;
  color: #222;
  font-weight: bold;
  margin: 25px 0;
}

.meta .author {
  color: #444;
}
.meta .avatar {
  width: 20px;
  height: 20px;
  border-radius: 2px;
  margin-right: 5px;
}
.meta img.avatar {
  display: inline-block;
}
.meta .bio {
  color: #999;
}
.answer + .answer {
  border-top: 2px solid #f6f6f6;
  padding-top: 30px;
}
.qr {
  background-color: #fff;
  text-align: center;
  border-top: 5px solid #F6F6F6;
  padding: 25px;
}
.qr .heading {
  font-size: 18px;
  color: #555;
}
.qr .subheading {
  font-size: 14px;
  color: #b8b8b8;
}
.qr-wrap {
  padding-top: 25px;
  padding-bottom: 15px;
}

.footer {
  padding: 20px 0;
  text-align: center;
  color: #b8b8b8;
  font-size: 13px;
}
.footer a {
  color: #b8b8b8;
  text-decoration: none;
}

.footer .view-origin{
  margin: 5px auto;
  display: inline-block;
  line-height: 50px;
  background: #f1f1f1;
  height: 50px;
  width: 90%;
  font-size: 16px;
  color: #616161;
  text-decoration: none;
}


.footer-download {
  display: none;
  margin-top: 10px;
  margin-bottom: 40px;
}
a.download-btn {
  display: inline-block;
  height: 60px;
  line-height: 60px;
  width: 280px;
  border: 1px solid #b8b8b8;
  background-color: #fdfdfd;
  font-size: 17px;
  border-radius: 10px;
  color: #444;
}
html.no-touch .footer a:hover {
  text-decoration: underline;
}

.icon-arrow-right {
  background-image: url("share-icons.png");
  background-repeat: no-repeat;
  display: inline-block;
  vertical-align: middle;
  background-position: -70px 0px;
  width: 12px;
  height: 20px;
}

.highlight {
  width: auto;
  overflow: auto;
  word-wrap: normal;
}
.highlight::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}
.highlight code {
  overflow: auto;
}
.highlight::-webkit-scrollbar-thumb:horizontal {
  border-radius: 6px;
  background-color: rgba(0,0,0,.5);
}
.highlight::-webkit-scrollbar-thumb:horizontal:hover {
  background-color: rgba(0,0,0,.6);
}
.highlight pre {
  margin: 0;
  white-space: pre;
}
.highlight .hll { background-color: #ffffcc }
.highlight  { background: #ffffff; }
.highlight .c { color: #999988; font-style: italic }
.highlight .err { color: #a61717; background-color: #e3d2d2 }
.highlight .k { font-weight: bold }
.highlight .o { font-weight: bold }
.highlight .cm { color: #999988; font-style: italic }
.highlight .cp { color: #999999; font-weight: bold }
.highlight .c1 { color: #999988; font-style: italic }
.highlight .cs { color: #999999; font-weight: bold; font-style: italic }
.highlight .gd { color: #000000; background-color: #ffdddd }
.highlight .ge { font-style: italic }
.highlight .gr { color: #aa0000 }
.highlight .gh { color: #999999 }
.highlight .gi { color: #000000; background-color: #ddffdd }
.highlight .go { color: #888888 }
.highlight .gp { color: #555555 }
.highlight .gs { font-weight: bold }
.highlight .gu { color: #aaaaaa }
.highlight .gt { color: #aa0000 }
.highlight .kc { font-weight: bold }
.highlight .kd { font-weight: bold }
.highlight .kn { font-weight: bold }
.highlight .kp { font-weight: bold }
.highlight .kr { font-weight: bold }
.highlight .kt { color: #445588; font-weight: bold }
.highlight .m { color: #009999 }
.highlight .s { color: #d32 }
.highlight .na { color: #008080 }
.highlight .nb { color: #008080 }
.highlight .nc { color: #445588; font-weight: bold }
.highlight .no { color: #008080 }
.highlight .ni { color: #800080 }
.highlight .ne { color: #990000; font-weight: bold }
.highlight .nf { color: #990000; font-weight: bold }
.highlight .nn { color: #555555 }
.highlight .nt { color: #000080 }
.highlight .nv { color: #008080 }
.highlight .ow { font-weight: bold }
.highlight .w { color: #bbbbbb }
.highlight .mf { color: #009999 }
.highlight .mh { color: #009999 }
.highlight .mi { color: #009999 }
.highlight .mo { color: #009999 }
.highlight .sb { color: #d32 }
.highlight .sc { color: #d32 }
.highlight .sd { color: #d32 }
.highlight .s2 { color: #d32 }
.highlight .se { color: #d32 }
.highlight .sh { color: #d32 }
.highlight .si { color: #d32 }
.highlight .sx { color: #d32 }
.highlight .sr { color: #808000 }
.highlight .s1 { color: #d32 }
.highlight .ss { color: #d32 }
.highlight .bp { color: #999999 }
.highlight .vc { color: #008080 }
.highlight .vg { color: #008080 }
.highlight .vi { color: #008080 }
.highlight .il { color: #009999 }



.bottom-recommend {
  display: none;
  padding-left: 12px;
  padding-right: 12px;
  font-size: 14px;
  color: #000;
  background: #fff;
}

.bottom-recommend a {
  margin-top: 12px;
  padding-top: 12px;
  display: block;
  height: 60px;
  font-size: 15px;
  line-height: 20px;
  color: #000;
  text-decoration: none;
  border-top: solid 1px #e1e1e1;
}

.bottom-recommend .link-image {
  float: right;
  width: 75px;
  height: 60px;
  margin-left: 18px;
  background-position: 50%;
  background-size: cover;
}

@media (max-width: 480px) {
  .bottom-recommend {
    display: block;
  }
  .new-download-banner {
    display: block;
  }


  .headline .meta {
    padding: 0 20px !important;
  }
  body{
    padding-top: 0;
  }
  blockquote, sup {
    line-height: 1.4em;
  }
  .global-header .main-wrap {
	margin: 0 10px;
  }
  .qr {
    display: none;
  }
  .footer {
    margin: 0;
    padding: 25px 0 25px 0;
    background-color: white;
  }
  .footer-download {
    display: block;
  }

  
  .download-banner {
    display: block;
  }

  html.show-download-banner .download-banner-v2 {
    display: block;
  }

  .icon-arrow-right {
    background-repeat: no-repeat;
    display: inline-block;
    vertical-align: middle;
    background-position: -70px -20px;
    width: 10px;
    height: 15px;
    margin-top: -7.5px;
  }
  .img-wrap .headline-title {
    bottom: 5px;
  }
  .content {
    line-height: 1.6em;
    margin: 10px 0 20px;
    font-size: 17px
  }
  .img-wrap .img-source {
    right: 10px !important;
    font-size: 9px;
  }
  .headline-background-link {
    padding: 20px 45px 20px 20px !important;
  }
  .headline-title {
    font-size: 21px;
    padding: 0 20px !important;
  }
  .question-title {
    font-size: 19px;
    margin: 20px 0;
  }
  .headline-background .heading {
    font-size: 15px !important;
    margin-bottom: 8px;
    line-height: 1em;
  }
  .headline-background .heading-content {
    font-size: 17px !important;
    line-height: 1.2em;
  }
  .question {
    padding: 0 20px !important;
  }
  .global-header {
    display: none;
  }
  .button {
    width: 60px;
  }
  .button i {
    margin-right: 0;
  }
  .answer + .answer {
    padding-top: 20px;
  }
  .button span {
    display: none;
  }
  .view-more {
    margin-bottom: 25px;
  }

  .footer .view-origin{
    color: #b8b8b8;
  }
}

@media only screen and (-webkit-min-device-pixel-ratio: 2), only screen and (min--moz-device-pixel-ratio: 2), only screen and (-o-min-device-pixel-ratio: 200/100), only screen and (min-device-pixel-ratio: 2) {
  .icon-arrow-right {
    background-image: url("share-icons@2x.png") !important;
    -webkit-background-size: 82px 55px;
    -moz-background-size: 82px 55px;
    background-size: 82px 55px;
  }
  .star {
    background-image: url("star@2x.png");
    -webkit-background-size: 9px 9px;
    -moz-background-size: 9px 9px;
    background-size: 9px 9px;
  }
  .web-logo {
    background-image: url("Web_Logo@2x.png") !important;
    -webkit-background-size: 126px 42px;
    -moz-background-size: 126px 42px;
    background-size: 126px 42px;
  }
}

.meta .meta-item {
  width:39%;
  overflow:hidden;
  white-space:nowrap;
  text-overflow:ellipsis;
  display:inline-block;
  color:#929292;
  margin-right:7px
}

.headline .meta {
  white-space:nowrap
  ;text-overflow:ellipsis;
  overflow:hidden;
  font-size:11px;
  color:#b8b8b8;
  margin:15px 0;
  padding:0 40px
}

.headline .meta a, .headline .meta a:hover {
  margin-top:2px;
  float:right;
  font-size:11px;
  color:#0066cf;
  text-decoration:none
}


    .header-for-mobile {
      height: 62px;
      overflow: hidden;
      line-height: 1;
      display: none;
	  background: #fff;
    }

    .header-for-mobile-btn {
      float: right;
      margin-top: 17px;
      border-radius: 3px;
      background-color: #57c200;
      padding: 8px 9px;
      color: #fff;
      font-size: 12px;
    }

    .header-for-mobile-logo-img {
      float: left;
      margin-top: 7px;
      width: 48px;
      height: 48px;
    }

    .header-for-mobile-download-link,
    .header-for-mobile-download-link:active,
    .header-for-mobile-download-link:visited,
    .header-for-mobile-download-link:hover {
      display: block;
      padding: 0 10px 0 16px;
      text-decoration: none;
    }

    .header-for-mobile-title {
      display: block;
      font-size: 18px;
      color: #000;
      padding: 12px 0 8px;
      margin-left: 58px;
    }
    .header-for-mobile-meta {
      display: block;
      font-size: 12px;
      color: #666;
      padding: 0 0 12px;
      margin-left: 58px;
    }
    @media (max-width: 480px) {
      .header-for-mobile {
        display: block;
      }
	  .footer {
		display: block;
	  }
    }

    .bottom-recommend-title {
      display: block;
      position: relative;
      top: -8px;
      height: 22px;
      width: 64px;
      margin: 0 auto;
      background: #fff;
      text-align: center;
      font-size: 10px;
      color: #666;
    }

    .bottom-recommend {
        border-top: solid 1px #e1e1e1;
	    background: #fff;
        padding-left: 0;
        padding-right: 0;
        margin: 0 12px;
    }

    .bottom-recommend a {
      margin-top: 0;
      padding-top: 0;
      display: block;
      border-top: none;
      background: #f9f9f9;
      padding: 10px;
      font-size: 15px;
    }
    .bottom-recommend .bottom-recommend-download-link, .bottom-recommend .bottom-recommend-download-link:hover,
    .bottom-recommend .bottom-recommend-download-link:active,
    .bottom-recommend .bottom-recommend-download-link:visited {
      margin-top: 15px;
      display: block;
      border-radius: 2px;
      height: 35px;
      line-height: 35px;
      font-size: 15px;
      background-color: #00b7f5;
      text-align: center;
      color: #fff;
      text-decoration: none;
    }
    .bottom-wrap {
	    background: #fff;
    }