body.logged_in {
  .flashes{
    .flash {
      @include gradient(#f7f1d3, #f5edc5);
      @include text-shadow(#fafafa);
      border-bottom: 1px solid #eee098;
      color: #cb9810;
      font-weight: bold;
      font-size: 1.1em;
      line-height: 1.0em;
      padding: 13px 30px 11px;
      position: relative;

      &.flash_notice {
        @include gradient(#dce9dd, #ccdfcd);
        border-bottom: 1px solid #adcbaf;
        color: #416347;
      }
      &.flash_error {
        @include gradient(#f5e4e4, #f1dcdc);
        border-bottom: 1px solid #e0c2c0;
        color: #b33c33;
      }
    }
  }
}

body.logged_out {
  .flash {
    @include no-shadow;
    @include text-shadow(#fff);
    background: none;
    color: #666;
    font-weight: bold;
    line-height: 1.0em;
    padding: 0;
  }
}

body.logged_in {
  .flashes{
    .flash {
      @include gradient(#f7f1d3, #f5edc5);
      @include text-shadow(#fafafa);
      border-bottom: 1px solid #eee098;
      color: #cb9810;
      font-weight: bold;
      font-size: 1.1em;
      line-height: 1.0em;
      padding: 13px 30px 11px;
      position: relative;

      &.flash_notice {
        @include gradient(#dce9dd, #ccdfcd);
        border-bottom: 1px solid #adcbaf;
        color: #416347;
      }
      &.flash_error {
        @include gradient(#f5e4e4, #f1dcdc);
        border-bottom: 1px solid #e0c2c0;
        color: #b33c33;
      }
    }
  }
}

body.logged_out {
  .flash {
    @include no-shadow;
    @include text-shadow(#fff);
    background: none;
    color: #666;
    font-weight: bold;
    line-height: 1.0em;
    padding: 0;
    margin-bottom: 8px;
  }
}

Fix overlapping flash message on non-logged pages
Fix overlapping flash message on non-logged pages

Add some margin-bottom to flash messages on logged out pages
