/* ------------------------------------------
 * IT书包
 * 网址：www.itshubao.com
 * 整理：yinq<3331653644@qq.com> 
 -------------------------------------------- */
* {
  box-sizing: border-box;
  margin: 0;
  border: 0;
}

html, body {
  height: 100%;
}

body {
  display: -webkit-box;
  display: -ms-flexbox;
  display: flex;
  -webkit-box-pack: center;
      -ms-flex-pack: center;
          justify-content: center;
  -webkit-box-align: center;
      -ms-flex-align: center;
          align-items: center;
  background: whitesmoke;
}

button {
  font-family: Source Sans Pro;
  font-size: 1rem;
  line-height: 3.5em;
  padding: 0 1.5em;
  background: gold;
  box-shadow: inset 0 -0.125rem rgba(0, 0, 0, 0.2);
  color: black;
  border-radius: 5em;
  cursor: pointer;
  -webkit-user-select: none;
     -moz-user-select: none;
      -ms-user-select: none;
          user-select: none;
  -webkit-transform-origin: 100% 100%;
          transform-origin: 100% 100%;
}
button:focus {
  outline: 0;
}

.shadow {
  margin-top: -.325rem;
  width: 100%;
  height: .75rem;
  background: -webkit-radial-gradient(closest-side, #dcdcdc, rgba(0, 0, 0, 0));
  background: radial-gradient(closest-side, #dcdcdc, rgba(0, 0, 0, 0));
  opacity: 0;
}