css矩形盒子实现虚线流动边框+css实现step连接箭头

由于项目里需要手写步骤条 且实现指定状态边框虚线流动效果，故使用css去绘制步骤条连接箭头和绘制边框流动效果

效果：

1.绘制步骤条连接箭头

    <ul class="process-list">
      <div v-for="(process, index) in processes" :key="index" class="flex items-center item-box">
        <li :class="active==process.id?'active':''">
          <span class="process-name">{{ process.name }}</span>
        </li>
        <div class="arrow"></div>
      </div>
    </ul>

// 绘制连接线
.arrow {
  display:inline-block;
  height:2px;
  width:80px;
  background-color:#909399;
  position:relative;
  margin-left: 10px;
  margin-right: 20px;
}
// 绘制箭头
.arrow:before {
  position:absolute;
  content:"";
  width:0;
  height:0;
  border:6px solid transparent;
  border-left:6px solid #909399;
  left:100%;
  top:50%;
  transform: translateY(-50%);
}

2.绘制流动虚线边框

  .process-item.active {
    color: #000;
    background-color: rgba(144, 147, 153, 0.2);
    position: relative;
    z-index: 2;
    background: linear-gradient(90deg, #2671e2 50%, transparent 0) repeat-x,
      linear-gradient(90deg, #2671e2 50%, transparent 0) repeat-x,
      linear-gradient(0deg, #2671e2 50%, transparent 0) repeat-y,
      linear-gradient(0deg, #2671e2 50%, transparent 0) repeat-y;
    background-color: rgba(144, 147, 153, 0.2);
    background-size: 8px 2px, 8px 2px, 2px 8px, 2px 8px;
    background-position: 0 0, 0 100%, 0 0, 100% 0;
    animation: linearGradientMove 0.3s infinite linear;
  }
  // 虚线动画
  @keyframes linearGradientMove {
    100% {
      background-position: 8px 0, -8px 100%, 0 -8px, 100% 8px;
    }
  }