Evgeny Kulakov

.v-treeview-node--leaf {
    /* margin-left: 26px; */
  margin-left: 0;
}
.v-treeview-node {
    /* margin-left: 26px; */
  margin-left: 0;
}

<template>
   <div>
     <header></header>
     <sidebar></sidebar>
     <slot name="content"></slot>
   </div>
</template>

<!-- some page -->

<my-layout>
  <div slot="content">
    <!-- page content -->
 </div>
</my-layout>