.purpose {
  position: absolute;
  top: 18px;
  left: 32px;
  font-family: Songti;
  min-height: 30px;
  display: flex;
  align-items: center;
}

.purpose-title {
  font-weight: bolder;
  font-size: 22px;
  color: 333333;
  margin-left: 10px;
}

.purpose-desc {
  font-size: 14px;
  color: #464646;
  margin-left: 10px;
}

.demo-btn {
  display: inline-block;
  position: absolute;
  right: 166px;
  top: 18px;
  width: 176px;
  height: 48px;
  line-height: 48px;
  text-align: center;
  background-color: rgba(135, 149, 225, 0.69);
  color: white;
  font-size: 18px;
  font-weight: bolder;
  border-radius: 6px;
  font-family: Songti;
}

a.demo-btn:active {
  background-color: rgba(135, 149, 225, 0.69);
}

a.demo-btn:hover {
  text-decoration: none;
  color: white;
}

.demo-btn:hover {
  background-color: rgba(135, 149, 225, 0.86);
}

.demo-btn-arrow {
  position: absolute;
  right: 8px;
  top: 50%;
  transform: translateY(-50%);
}

/* --- */
body {
  padding-top: 1px;
}

.main {
  margin: 114px auto 0 253px;
}

.features {
  max-width: 668px;
}

.feature {
  min-height: 110px;
  padding: 25px 32px 16px 20px;
  border-radius: 4px;
  border: 1px solid transparent;
  position: relative;
  transition: 300ms all ease-in-out;
  margin-bottom: 16px;
}

.feature-title {
  font-size: 18px;
  font-family: Songti;
  color: #000000;
  height: 25px;
}

.feature-text {
  font-size: 16px;
  font-family: Kaiti;
  color: #333333;
  min-height: 22px;
  margin-top: 6px;
}

.feature:hover {
  border-color: #00ee00;
}

.feature:hover .feature-right {
  opacity: 1;
}

.feature-right {
  opacity: 0;
  transition: inherit;
  position: absolute;
  right: 24px;
  top: 50%;
  transform: translateY(-50%);
  width: 14px;
  height: 23px;
  -webkit-mask-position: 50% 50%;
  mask-position: 50% 50%;
  -webkit-mask-repeat: no-repeat;
  mask-repeat: no-repeat;
  -webkit-mask-size: 100%;
  mask-size: 100%;
  background-color: currentColor;
  mask-image: url("data:image/svg+xml,%3Csvg width='14px' height='23px' viewBox='0 0 14 23' version='1.1'%0Axmlns='http://www.w3.org/2000/svg' xmlns:xlink='http://www.w3.org/1999/xlink'%3E%3Cg id='介绍页' stroke='none' stroke-width='1' fill='none' fill-rule='evenodd'%3E%3Cg transform='translate(-883.000000, -162.000000)' fill='%23999999' fill-rule='nonzero' id='features'%3E%3Cg transform='translate(253.000000, 114.000000)' id='f'%3E%3Cpolygon id='路径' points='632.663968 48 630 50.6639676 638.653171 59.3360324 630 68.0080972 632.663968 70.6720648 644 59.3360324'%3E%3C/polygon%3E%3C/g%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
  -webkit-mask-image: url("data:image/svg+xml,%3Csvg width='14px' height='23px' viewBox='0 0 14 23' version='1.1'%0Axmlns='http://www.w3.org/2000/svg' xmlns:xlink='http://www.w3.org/1999/xlink'%3E%3Cg id='介绍页' stroke='none' stroke-width='1' fill='none' fill-rule='evenodd'%3E%3Cg transform='translate(-883.000000, -162.000000)' fill='%23999999' fill-rule='nonzero' id='features'%3E%3Cg transform='translate(253.000000, 114.000000)' id='f'%3E%3Cpolygon id='路径' points='632.663968 48 630 50.6639676 638.653171 59.3360324 630 68.0080972 632.663968 70.6720648 644 59.3360324'%3E%3C/polygon%3E%3C/g%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
  color: #999999;
}

.startbtn {
  display: inline-block;
  width: 294px;
  height: 80px;
  line-height: 80px;
  background: #acd8a7;
  box-shadow: 0 2px 4px 0 rgba(0, 0, 0, 0.5);
  border-radius: 40px;
  font-family: Songti;
  font-size: 18px;
  color: #333333;
  text-align: center;
  margin-top: 72px;
  margin-bottom: 72px;
}

a.startbtn:hover {
  text-decoration: none;
  color: currentColor;
}

a.startbtn:active {
  background-color: #acd8a7;
}

.startbtn:hover {
  background-color: #9cce97;
}

/* --- mobile --- */
@media screen and (max-width: 600px) {
  .demo-btn {
    position: relative;
    left: 0;
    right: 0;
    margin: 32px auto 56px auto;
    display: block;
  }
  .purpose {
    flex-wrap: wrap;
    position: relative;
    left: 0;
    right: 0;
    padding-left: 16px;
  }
  .purpose-desc {
    display: flex;
    margin-left: 2px;
  }
  .main {
    margin: 10px;
  }

  .feature {
    padding: 16px 24px 16px 16px;
  }
  .feature-right {
    right: 8px;
  }

  .startbtn {
    width: 232px;
    height: 56px;
    line-height: 56px;
    font-size: 17px;
    margin: 56px auto;
    display: block;
  }
}