bitwarden-desktop/src/scss/environment.scss

html.os_windows {
  body {
    border-top: 1px solid #dddddd;
  }

  &.theme_dark body {
    border-top-color: #000000;
  }
}

html.os_macos {
  body.layout_frontend {
    -webkit-app-region: drag;

    button,
    a,
    i,
    b,
    span,
    input,
    p,
    h1,
    h2,
    h3,
    h4,
    h5,
    h6,
    img,
    select,
    textarea,
    label,
    .box,
    .modal-backdrop {
      -webkit-app-region: no-drag;
    }
  }

  #login-page {
    .content {
      a.settings-icon {
        position: absolute;
        left: unset;
        right: 20px;

        span {
          margin-right: 8px;
          float: left;
        }
      }
    }
  }

  .vault .header-search {
    -webkit-app-region: drag;

    input,
    i {
      -webkit-app-region: no-drag;
    }
  }

  .vault > .groupings > .content > .inner-content {
    padding-top: 0;
  }
}