diff --git a/apps/mapgen-studio/src/features/configOverrides/rjsfTemplates.tsx b/apps/mapgen-studio/src/features/configOverrides/rjsfTemplates.tsx
index 7a995ab42f..701075874f 100644
--- a/apps/mapgen-studio/src/features/configOverrides/rjsfTemplates.tsx
+++ b/apps/mapgen-studio/src/features/configOverrides/rjsfTemplates.tsx
@@ -14,7 +14,13 @@ export type BrowserConfigFormContext = {
 // tokens (`card`/`muted`/`border`/`accent`/…), so there is no `lightMode` read.
 const FORM = {
   card: "bg-card border-border",
-  nested: "bg-muted/40 border-border-subtle",
+  // Group well: nesting is a surface, not an indent (Pass-3 config-surface
+  // spec). One recess below the stage card — tinted toward the page token so
+  // groups read as machined slots in the slate. `background` sits below `card`
+  // in BOTH themes (5%<9% dark, 96%<100% light), so the tint recesses in both.
+  // Two surface tiers maximum: card → well; deeper nesting adds headings and
+  // rhythm only, never a third surface.
+  well: "bg-background/40 border-border-subtle",
   divider: "border-border",
   // Field labels sit a full tier above prose (Pass-2 form hierarchy): labels are
   // foreground anchors the eye scans; descriptions/help/gs-comments recede on the
@@ -25,6 +31,19 @@ const FORM = {
   text: "text-foreground",
   borderSubtle: "border-border-subtle",
   button: "bg-muted text-foreground border-border hover:bg-accent",
+  // Group headings are eyebrows: the well's geometry carries the grouping, so
+  // its caption recedes below field labels (the brightest scan line in a card).
+  groupHeading: "text-label font-semibold uppercase tracking-wider text-muted-foreground",
+  subGroupHeading: "text-label font-semibold uppercase tracking-wider text-muted-foreground/70",
+  // Rhythm on the 4px base (Pass-3): 4px inside a field block, 8px between
+  // sibling fields, 12px between groups/stage sections. Group wells carry
+  // `my-1`, which composes with the sibling gap to the 12px group step.
+  rhythm: {
+    field: "gap-1",
+    siblings: "gap-2",
+    sections: "gap-3",
+    groupPull: "my-1",
+  },
 } as const;
 
 function humanizeSchemaLabel(label: string): string {
@@ -85,7 +104,7 @@ export function BrowserConfigFieldTemplate(
 
   if (!showLabel) {
     return (
-      <div className={["flex flex-col gap-1", classNames].filter(Boolean).join(" ")}>
+      <div className={[`flex flex-col ${FORM.rhythm.field}`, classNames].filter(Boolean).join(" ")}>
         <div className={textClass}>{children}</div>
         {description && !suppressDescription ? <div className={`text-data ${labelClass}`}>{description}</div> : null}
         {renderGsComments({ schema: props.schema, className: labelClass })}
@@ -96,7 +115,7 @@ export function BrowserConfigFieldTemplate(
   }
 
   return (
-    <div className={["flex flex-col gap-1", classNames].filter(Boolean).join(" ")}>
+    <div className={[`flex flex-col ${FORM.rhythm.field}`, classNames].filter(Boolean).join(" ")}>
       <FieldRow>
         <label className={`text-data min-w-[96px] ${FORM.fieldLabel}`} htmlFor={id}>
           <span className="font-medium">{prettyLabel}</span>
@@ -127,7 +146,11 @@ export function BrowserConfigObjectFieldTemplate(
   const textClass = FORM.text;
 
   if (isRoot) {
-    return <div className="flex flex-col gap-2">{properties.filter((p) => !p.hidden).map((p) => p.content)}</div>;
+    return (
+      <div className={`flex flex-col ${FORM.rhythm.sections}`}>
+        {properties.filter((p) => !p.hidden).map((p) => p.content)}
+      </div>
+    );
   }
 
   if (isTransparent) {
@@ -138,7 +161,7 @@ export function BrowserConfigObjectFieldTemplate(
   const isStage = depth === 1;
 
   const content = (
-    <div className="flex flex-col gap-1.5">
+    <div className={`flex flex-col ${FORM.rhythm.siblings}`}>
       {!isStage && description ? (
         <div className={`text-data ${labelClass}`}>{description}</div>
       ) : null}
@@ -160,17 +183,26 @@ export function BrowserConfigObjectFieldTemplate(
     );
   }
 
-  const headingClass = `${depth >= 3 ? "text-data" : "text-xs"} font-semibold ${textClass}`;
-  const inlineBorder = `${depth >= 3 ? "pl-2" : "pl-2.5"} border-l ${FORM.borderSubtle}`;
-  const groupWrapper = `flex flex-col gap-0.5`;
+  // Depth 2: the one well tier inside a stage card. Depth ≥3: no further
+  // surface — an eyebrow heading and the sibling rhythm carry the structure
+  // (surface nesting is capped at card → well; see FORM.well).
+  if (depth === 2) {
+    return (
+      <section className={`rounded-md border p-2 ${FORM.rhythm.groupPull} ${FORM.well}`}>
+        <header className="pb-1.5">
+          <div className={FORM.groupHeading}>{prettyTitle}</div>
+        </header>
+        {content}
+      </section>
+    );
+  }
+
   return (
-    <section className={groupWrapper}>
+    <section className={`flex flex-col gap-1 ${FORM.rhythm.groupPull}`}>
       <header>
-        <div className={headingClass}>{prettyTitle}</div>
+        <div className={FORM.subGroupHeading}>{prettyTitle}</div>
       </header>
-      <div className={inlineBorder}>
-        {content}
-      </div>
+      {content}
     </section>
   );
 }
@@ -181,13 +213,15 @@ export function BrowserConfigArrayFieldTemplate(
   const { title, items, canAdd, onAddClick, disabled, readonly, schema } = props;
   const prettyTitle = title ? humanizeSchemaLabel(title) : "Items";
   const allowMutations = !disabled && !readonly;
-  const textClass = FORM.text;
   const labelClass = FORM.label;
 
+  // Arrays ride the same well tier as object groups (one surface recess);
+  // items separate by hairline borders only — a tinted item box would be a
+  // third surface tier, which the elevation scheme caps out.
   return (
-    <section className={`rounded-md border p-2 ${FORM.nested}`}>
+    <section className={`rounded-md border p-2 ${FORM.rhythm.groupPull} ${FORM.well}`}>
       <div className="flex items-center gap-2">
-        <div className={`text-xs font-semibold ${textClass}`}>{prettyTitle}</div>
+        <div className={FORM.groupHeading}>{prettyTitle}</div>
         <div style={{ flex: 1 }} />
         {canAdd && allowMutations ? (
           <button
@@ -201,13 +235,13 @@ export function BrowserConfigArrayFieldTemplate(
       </div>
       {renderGsComments({ schema, className: labelClass })}
       <div className={`my-2 border-t ${FORM.divider}`} />
-      <div className="flex flex-col gap-2">
+      <div className={`flex flex-col ${FORM.rhythm.siblings}`}>
         {items.map((item, index) => {
           // RJSF v6 types this as ReactElement[], but some templates/versions
           // pass an "item" object that wraps the actual element in `.children`.
           const content = (item as any)?.children ?? (item as any)?.props?.children ?? item;
           return (
-            <div key={item.key ?? index} className={`rounded-md border p-2 ${FORM.nested}`}>
+            <div key={item.key ?? index} className={`rounded border p-2 ${FORM.borderSubtle}`}>
               {content}
             </div>
           );
diff --git a/apps/mapgen-studio/test/config/rjsfFieldTemplateErrors.test.tsx b/apps/mapgen-studio/test/config/rjsfFieldTemplateErrors.test.tsx
index ffe99d56d4..7c1d9c1cce 100644
--- a/apps/mapgen-studio/test/config/rjsfFieldTemplateErrors.test.tsx
+++ b/apps/mapgen-studio/test/config/rjsfFieldTemplateErrors.test.tsx
@@ -2,8 +2,11 @@ import { renderToStaticMarkup } from "react-dom/server";
 import { describe, expect, it } from "vitest";
 import type { FieldTemplateProps, RJSFSchema } from "@rjsf/utils";
 
+import type { ObjectFieldTemplateProps } from "@rjsf/utils";
+
 import {
   BrowserConfigFieldTemplate,
+  BrowserConfigObjectFieldTemplate,
   type BrowserConfigFormContext,
 } from "../../src/features/configOverrides/rjsfTemplates";
 
@@ -56,3 +59,34 @@ describe("BrowserConfigFieldTemplate error live regions", () => {
     expect(html).toMatch(/text-muted-foreground/);
   });
 });
+
+describe("BrowserConfigObjectFieldTemplate nesting surfaces", () => {
+  type ObjectProps = ObjectFieldTemplateProps<unknown, RJSFSchema, BrowserConfigFormContext>;
+
+  function renderGroup(path: (string | number)[]): string {
+    const props = {
+      title: "Mesh Resolution",
+      description: undefined,
+      properties: [{ hidden: false, content: <div>field</div>, name: "x" }],
+      fieldPathId: { path, id: path.join("_") },
+      schema: { type: "object" } as RJSFSchema,
+      registry: { formContext: { transparentPaths: new Set<string>() } },
+    };
+    return renderToStaticMarkup(
+      <BrowserConfigObjectFieldTemplate {...(props as unknown as ObjectProps)} />
+    );
+  }
+
+  it("renders a depth-2 group as a recessed well, not an indent rule", () => {
+    const html = renderGroup(["foundation", "meshResolution"]);
+    // Pass-3 config-surface spec: surface tier (page-tint well), no border-l ladder.
+    expect(html).toContain("bg-background/40");
+    expect(html).not.toContain("border-l");
+  });
+
+  it("adds no third surface tier at depth 3", () => {
+    const html = renderGroup(["foundation", "meshResolution", "advanced"]);
+    expect(html).not.toContain("bg-background/40");
+    expect(html).not.toContain("border-l");
+  });
+});
diff --git a/openspec/changes/mapgen-studio-config-surface/tasks.md b/openspec/changes/mapgen-studio-config-surface/tasks.md
index 9968349cb2..43e3970e23 100644
--- a/openspec/changes/mapgen-studio-config-surface/tasks.md
+++ b/openspec/changes/mapgen-studio-config-surface/tasks.md
@@ -1,20 +1,20 @@
 ## 1. Implementation
 
-- [ ] 1.1 Codify `FORM` rhythm + well surface classes in `rjsfTemplates.tsx`
+- [x] 1.1 Codify `FORM` rhythm + well surface classes in `rjsfTemplates.tsx`
       (fieldGap 4 / siblingGap 8 / groupGap 12; well = page-tint + subtle
       border + rounded + p-2).
-- [ ] 1.2 Object template: depth≥2 groups render as wells (drop `border-l` +
+- [x] 1.2 Object template: depth≥2 groups render as wells (drop `border-l` +
       `pl-*` ladder); depth≥3 adds heading + rhythm only; headings move to the
       eyebrow tier.
-- [ ] 1.3 Array template: unify onto the well treatment.
-- [ ] 1.4 Apply rhythm to root/stage content gaps.
-- [ ] 1.5 Update `rjsfFieldTemplateErrors.test.tsx` assertions if class names
+- [x] 1.3 Array template: unify onto the well treatment.
+- [x] 1.4 Apply rhythm to root/stage content gaps.
+- [x] 1.5 Update `rjsfFieldTemplateErrors.test.tsx` assertions if class names
       shifted; add a well/no-indent assertion for a nested group.
 
 ## 2. Verification
 
-- [ ] 2.1 `bun run openspec -- validate mapgen-studio-config-surface --strict`
-- [ ] 2.2 tsc + mapgen-studio vitest green
-- [ ] 2.3 Visual on :5173, dark AND light: stage card → group well reads as two
+- [x] 2.1 `bun run openspec -- validate mapgen-studio-config-surface --strict`
+- [x] 2.2 tsc + mapgen-studio vitest green
+- [x] 2.3 Visual on :5173, dark AND light: stage card → group well reads as two
       recess steps (squint test shows chunking); no left-rule indents; rhythm
       visibly tiered (field < sibling < group). Screenshot both themes.