next-ucap-messenger/projects/ucap-webmessenger-app/src/app/layouts/native/components/top-bar.component.scss

:host {
  .app-layout-native-title-bar {
    -webkit-user-select: none;
    -webkit-app-region: drag;

    position: fixed;
    right: 0;
    top: 0;
    display: flex;
    padding: 0 10px;
    cursor: pointer;
    height: 30px;
    color:#ffffff;
    //background: rgba(37, 27, 30, 0.9);
    //border-bottom: 1px solid #d5dadb;

    .app-layout-native-title-bar-logo {
      width: 16px;
      height: 16px;
    }

    .app-layout-native-title-bar-title {
      padding-left: 8px;
      font-size: 12px;
    }

    .app-layout-native-title-bar-spacer {
      flex: 1 1 auto;
    }

    .app-layout-native-title-bar-actions {
      position: relative;

      .button {
        -webkit-app-region: no-drag;
        outline: 0;
        cursor: pointer;
        border: none;
        height: 30px;
        min-width: 30px;
        max-width: 30px;
        padding: 5px;
        line-height: 10px;
        border-radius: 0;
        background: transparent;
        transition: background 0.2s linear, color 0.2s linear;
        text-align: center;
        font-size: 10px;
        vertical-align: middle;
        margin-left:6px;
        transform: translateY(-2px);
        .mat-icon {
          //transform: translateY(-2px);
          width: 16px;
          height: 16px;
          min-height:16px;
          min-width:16px;
          font-size: 16px;
        }

        &.app-layout-native-title-bar-close,
        &.app-layout-native-title-bar-maximize,
        &.app-layout-native-title-bar-minimize {
          color: darken(white, 20%);
          font-weight: lighter;
        }

        // &.app-layout-native-title-bar-minimize .mat-icon {
        //   transform: translateY(-43%);
        // }

        &:hover {
          &.app-layout-native-title-bar-close {
            background: darken(#000000, 10%);
            color: darken(white, 0);
          }

          &.app-layout-native-title-bar-minimize {
            background: darken(#000000, 10%);
            color: darken(white,0);
          }

          &.app-layout-native-title-bar-maximize {
            background: darken(#000000, 10%);
            color: darken(white, 0);
          }
        }
      }
    }
  }
}