hexo-theme-next/source/css/_common/components/post/post-reward.styl

.reward-container {
  margin: 20px auto;
  padding: 10px 0;
  text-align: center;
  width: 90%;

  button {
    background: transparent;
    border: 2px solid $sidebar-highlight;
    border-radius: 2px;
    color: $sidebar-highlight;
    cursor: pointer;
    line-height: 2;
    outline: 0;
    padding: 0 15px;
    transition: all $transition-ease;
    vertical-align: text-top;

    &:hover {
      background: $sidebar-highlight;
      border: 2px solid transparent;
      color: white;
    }
  }
}

#qr {
  padding-top: 20px;

  img {
    display: inline-block;
    margin: .8em 2em 0 2em;
    max-width: 100%;
    width: 180px;
  }

  if (hexo-config('reward_settings.animation')) {
    div:hover p {
      animation: roll .1s infinite linear;
    }

    @keyframes roll {
      from {
        transform: rotateZ(30deg);
      }

      to {
        transform: rotateZ(-30deg);
      }
    }
  }
}