grafana/public/sass/components/_jsontree.scss

/* Structure */
json-tree {
  .json-tree-key {
    vertical-align: middle;
  }
  .expandable {
    position: relative;
    &::before {
      pointer-events: none;
    }
    &::before,
    & > .json-tree-key {
      cursor: pointer;
    }
  }
  .json-tree-branch-preview {
    display: inline-block;
    vertical-align: middle;
  }
}

/* Looks */
json-tree {
  ul {
    padding-left: $spacer;
  }
  li,
  ul {
    list-style: none;
  }
  li {
    line-height: 1.3rem;
  }
  .json-tree-key {
    color: $variable;
    padding: 5px 10px 5px 15px;
    &::after {
      content: ":";
    }
  }
  json-node.expandable {
    &::before {
      content: "\25b6";
      position: absolute;
      left: 0px;
      font-size: 8px;
      transition: transform 0.1s ease;
    }
    &.expanded::before {
      transform: rotate(90deg);
    }
  }
  .json-tree-leaf-value,
  .json-tree-branch-preview {
    word-break: break-all;
  }
  .json-tree-branch-preview {
    overflow: hidden;
    font-style: italic;
    max-width: 40%;
    height: 1.5em;
    opacity: 0.7;
  }
}