ionic-framework/scss/ionic/structure/_bar.scss

// Use Flexbox for our header and footer bars
.bar {
  @include disable-user-select();

  position: fixed;
  right: 0;
  left: 0;
  z-index: 10;
  width: 100%;

  box-sizing: border-box;

  height: $barHeight;

  padding: $barPaddingPortrait;

  // Title inside of a bar is centered
  .title {
    position: absolute;
    z-index: 0;

    width: 100%;
    top: 0;
    left: 0;

    line-height: $barHeight;

    margin: 0;
    //padding: $barPaddingVertical 0px;

    text-align: center;
    white-space: nowrap;
    font-size: $barTitleFontSize;

  }


  .title a {
    color: inherit;
  }

  // Place the last button in a bar on the right of the bar
  /*
  .title + .button:last-child,
  .button + .button:last-child,
  .button.pull-right {
    position: absolute;
    top: 5px;
    right: 5px;
  }
  */
}

.buttons {
  position: absolute;

  // Lift the buttons container above the title
  z-index: 1;

  padding: $barPaddingPortrait;
  line-height: $barButtonsLineHeight;


  .button {
    padding: 6px 12px;
    line-height: 14px;
  }
}
.buttons:first-child {
  left: 0;
  top: 0;
}
.buttons:last-child {
  right: 0;
  top: 0;
}

// Header at top
.bar-header {
  top: 0;
}

// Footer at bottom
.bar-footer {
  bottom: 0;
}

// Don't render padding if the bar is just for tabs
.bar-tabs {
  padding: 0;
}

.bar-header-secondary {
  top: $barHeight;
}
.bar-footer-secondary {
  bottom: $barHeight;
}

/* Pad top/bottom of content so it doesn't hide behind .bar-title and .bar-tab.
   Note: For these to work, content must come after both bars in the markup */
.has-header {
  top: $barHeight;
}

.has-footer {
  bottom: $barHeight;
}