ionic-framework/scss/_platform.scss

/**
 * Platform
 * --------------------------------------------------
 */

.platform-ios7 {
  .bar-header {
    height: 64px;

    > * {
      margin-top: 20px;
    }
  }

  .has-header {
    top: 64px;
  }

  .bar-subheader {
    top: 64px;
  }

  .has-subheader {
    top: 108px;
  }
}

.platform-android {
  .bar-header {
    height: 48px;
  }

  .has-header {
    top: 48px;
  }

  .bar-subheader {
    top: 48px;
  }

  .has-subheader {
    top: 96px;
  }

  .title {
    line-height: 48px;
  }
}