fix headings

apps/client/src/features/editor/styles/core.css

@@ -52,7 +52,34 @@
 
   h1,
   h2,
-  h3,
+  h3 {
+    letter-spacing: -0.01em;
+    line-height: 1.2;
+    font-weight: 600;
+    margin-bottom: 0;
+  }
+
+  h1 strong,
+  h2 strong,
+  h3 strong {
+    font-weight: 600;
+  }
+
+  h1 {
+    font-size: 1.875rem;
+    margin-top: 1.875rem;
+  }
+
+  h2 {
+    font-size: 1.5rem;
+    margin-top: 1.5rem;
+  }
+
+  h3 {
+    font-size: 1.25rem;
+    margin-top: 1.25rem;
+  }
+
   h4,
   h5,
   h6 {
@@ -243,3 +270,10 @@
 .actionIconGroup {
   background: var(--mantine-color-body);
 }
+
+.page-title .ProseMirror h1 {
+  font-size: 2.5rem;
+  font-weight: 700;
+  margin-top: 0;
+  margin-bottom: 0.75em;
+}