Fix tabs layout

Co-Authored-By: Nathan Sobo <nathan@zed.dev>

gpui/src/elements/container.rs

@@ -53,6 +53,11 @@ impl Container {
         self
     }
 
+    pub fn with_padding_bottom(mut self, padding: f32) -> Self {
+        self.padding.bottom = padding;
+        self
+    }
+
     pub fn with_background_color(mut self, color: impl Into<ColorU>) -> Self {
         self.background_color = Some(color.into());
         self

gpui/src/elements/line_box.rs

@@ -38,7 +38,11 @@ impl Element for LineBox {
             .select_font(self.family_id, &self.font_properties)
         {
             Ok(font_id) => {
-                let line_height = ctx.font_cache.bounding_box(font_id, self.font_size).y();
+                let line_height = ctx
+                    .font_cache
+                    .bounding_box(font_id, self.font_size)
+                    .y()
+                    .ceil();
                 let child_max = vec2f(
                     constraint.max.x(),
                     ctx.font_cache.ascent(font_id, self.font_size)