bootstrap/less/alerts-fixed.less

// Fixed alerts
// Position to the top or bottom.
// ------------------------------------------------

.alert-fixed-top,
.alert-fixed-bottom {
  position: fixed;
  width: 100%;
  z-index: @zindex-alert-fixed;
  border-radius: 0;
  margin: 0;
  left: 0;

  @media (min-width: @alert-fixed-width) {
    width: @alert-fixed-width;
    left: 50%;
    margin-left: (-1 * (@alert-fixed-width / 2));
  }
}

.alert-fixed-top {
  top: 0;
  border-width: 0 0 1px 0;
  
  @media (min-width: @alert-fixed-width) {
    .border-bottom-radius(@alert-border-radius);
    border-width: 0 1px 1px 1px;
  }
}

.alert-fixed-bottom {
  bottom: 0;
  border-width: 1px 0 0 0;
  
  @media (min-width: @alert-fixed-width) {
    .border-top-radius(@alert-border-radius);
    border-width: 1px 1px 0 1px;
  }
}