SidebarButton.vue

<template>
  <div
    class="sidebar-button"
    @click="$emit('toggle-sidebar')"
  >
    <svg
      class="icon"
      xmlns="http://www.w3.org/2000/svg"
      aria-hidden="true"
      role="img"
      viewBox="0 0 448 512"
    >
      <path
        fill="currentColor"
        d="M436 124H12c-6.627 0-12-5.373-12-12V80c0-6.627 5.373-12 12-12h424c6.627 0 12 5.373 12 12v32c0 6.627-5.373 12-12 12zm0 160H12c-6.627 0-12-5.373-12-12v-32c0-6.627 5.373-12 12-12h424c6.627 0 12 5.373 12 12v32c0 6.627-5.373 12-12 12zm0 160H12c-6.627 0-12-5.373-12-12v-32c0-6.627 5.373-12 12-12h424c6.627 0 12 5.373 12 12v32c0 6.627-5.373 12-12 12z"
        class=""
      />
    </svg>
  </div>
</template>

<style lang="stylus">
.sidebar-button
  cursor pointer
  display none
  width 1.25rem
  height 1.25rem
  position absolute
  padding 0.6rem
  top 0.6rem
  left 1rem
  .icon
    display block
    width 1.25rem
    height 1.25rem

@media (max-width: $MQMobile)
  .sidebar-button
    display block
</style>