diff --git a/tildes/scss/_spectre_variables.scss b/tildes/scss/_spectre_variables.scss
index d0ba4ec..dfe129b 100644
--- a/tildes/scss/_spectre_variables.scss
+++ b/tildes/scss/_spectre_variables.scss
@@ -12,5 +12,5 @@ $size-xs: 480px;
 $size-sm: 600px;
 $size-md: $show-sidebar-width;
 $size-lg: 960px;
-$size-xl: 1080px;
-$size-2x: 1200px;
+$size-xl: 1200px;
+$size-2x: 1500px;
diff --git a/tildes/scss/_variables.scss b/tildes/scss/_variables.scss
index 3dbd13e..20e984e 100644
--- a/tildes/scss/_variables.scss
+++ b/tildes/scss/_variables.scss
@@ -7,7 +7,10 @@ $show-sidebar-width: 840px;
 $min-touch-size: 26px;
 
 // Maximum width of the <main> element
-$main-max-width: 70rem;
+$main-max-width: 1400px;
 
 // Maximum width to allow on "paragraph-like" text
 $paragraph-max-width: 40rem;
+
+// The approximate size where the site's width "maxes out" (larger just adds margins)
+$size-max: $main-max-width + $sidebar-width;
diff --git a/tildes/scss/modules/_comment.scss b/tildes/scss/modules/_comment.scss
index 0ebd03f..4ad0359 100644
--- a/tildes/scss/modules/_comment.scss
+++ b/tildes/scss/modules/_comment.scss
@@ -96,7 +96,7 @@
 .comment-tree-replies {
   margin-left: 0.4rem;
 
-  @media (min-width: $size-md) {
+  @media (min-width: $size-xl) {
     margin-left: 1rem;
   }
 }
@@ -276,4 +276,29 @@
   }
 }
 
-@include flatten-single-replies-above-depth(4);
+@media (max-width: $size-xs) {
+  @include flatten-single-replies-above-depth(4);
+}
+@media (min-width: $size-xs) and (max-width: $size-sm) {
+  @include flatten-single-replies-above-depth(7);
+}
+@media (min-width: $size-sm) and (max-width: $size-md) {
+  @include flatten-single-replies-above-depth(10);
+}
+@media (min-width: $size-md) and (max-width: $size-lg) {
+  // drop back down because sidebar shows up, which actually gives less space
+  @include flatten-single-replies-above-depth(7);
+}
+@media (min-width: $size-lg) and (max-width: $size-xl) {
+  @include flatten-single-replies-above-depth(9);
+}
+@media (min-width: $size-xl) and (max-width: $size-2x) {
+  // don't increase much yet since left indent increases, so space is reduced again
+  @include flatten-single-replies-above-depth(12);
+}
+@media (min-width: $size-2x) and (max-width: $size-max) {
+  @include flatten-single-replies-above-depth(20);
+}
+@media (min-width: $size-max) {
+  @include flatten-single-replies-above-depth(30);
+}