diff --git a/scripts/capture-home.mjs b/scripts/capture-home.mjs
index f9069e13..060887eb 100644
--- a/scripts/capture-home.mjs
+++ b/scripts/capture-home.mjs
@@ -371,6 +371,26 @@ try {
         const stage = page.locator('#evidence .experiment-explorer');
         await stage.scrollIntoViewIfNeeded();
         const diagnostics = await page.evaluate(() => {
+          const sectionStyle = (node) => {
+            if (!(node instanceof HTMLElement)) return null;
+            const css = getComputedStyle(node);
+            return {
+              fontFamily: css.fontFamily,
+              fontSize: Number.parseFloat(css.fontSize),
+              fontWeight: css.fontWeight,
+              lineHeight: Number.parseFloat(css.lineHeight),
+              tracking: css.letterSpacing,
+            };
+          };
+          const sectionHeadings = [...document.querySelectorAll('[data-stage] .stage-heading')].map(sectionStyle);
+          const sectionIntros = [...document.querySelectorAll('[data-stage] .stage-intro')].map(sectionStyle);
+          const aboutHeading = sectionStyle(document.querySelector('#about-title'));
+          const aboutIntro = sectionStyle(document.querySelector('.about-summary'));
+          const heroHeading = sectionStyle(document.querySelector('.hero-heading'));
+          const cardHeadings = [
+            '.card-headline', '.runtime-card__identity h4', '.value-headline',
+            '.mcb-model-card__name'
+          ].map(selector => sectionStyle(document.querySelector(selector))).filter(Boolean);
           const root = document.querySelector('#evidence .experiment-explorer');
           const tabs = [...root.querySelectorAll('[data-experiment-tab]')];
           const rail = root.querySelector('[data-experiment-rail]');
@@ -398,6 +418,7 @@ try {
           const titles = [...root.querySelectorAll('h3, h4, .experiment-mobile-chooser label')];
           return {
             theme: document.documentElement.dataset.theme,
+            typographyAudit: { sectionHeadings, sectionIntros, aboutHeading, aboutIntro, heroHeading, cardHeadings },
             pageOverflowPx: Math.max(0, document.documentElement.scrollWidth - window.innerWidth),
             selectedTab: tabs.find((t) => t.getAttribute('aria-selected') === 'true')?.dataset.trackId,
             publishedCount: tabs.filter((t) => t.dataset.published === 'true').length,
@@ -498,6 +519,31 @@ try {
         measureChecks.push(check);
         if (
           diagnostics.theme !== theme ||
+          diagnostics.typographyAudit.sectionHeadings.length !== 4 ||
+          diagnostics.typographyAudit.sectionIntros.length !== 4 ||
+          diagnostics.typographyAudit.sectionHeadings.some(heading =>
+            !heading?.fontFamily.includes('Plus Jakarta Sans') || heading.fontWeight !== '800' ||
+            !Number.isFinite(heading.fontSize)) ||
+          Math.max(...diagnostics.typographyAudit.sectionHeadings.map(heading => heading.fontSize)) -
+            Math.min(...diagnostics.typographyAudit.sectionHeadings.map(heading => heading.fontSize)) > 0.6 ||
+          diagnostics.typographyAudit.sectionIntros.some(intro =>
+            !intro?.fontFamily.includes('Inter') || intro.fontSize < 15) ||
+          (viewport.width <= 760 &&
+            Math.max(...diagnostics.typographyAudit.sectionIntros.map(intro => intro.fontSize)) -
+              Math.min(...diagnostics.typographyAudit.sectionIntros.map(intro => intro.fontSize)) > 0.6) ||
+          !diagnostics.typographyAudit.aboutHeading?.fontFamily.includes('Plus Jakarta Sans') ||
+          diagnostics.typographyAudit.aboutHeading.fontWeight !== '800' ||
+          Math.abs(diagnostics.typographyAudit.aboutHeading.fontSize -
+            diagnostics.typographyAudit.sectionHeadings[0].fontSize) > 0.6 ||
+          !diagnostics.typographyAudit.aboutIntro?.fontFamily.includes('Inter') ||
+          (viewport.width <= 760 && Math.abs(diagnostics.typographyAudit.aboutIntro.fontSize -
+            diagnostics.typographyAudit.sectionIntros[0].fontSize) > 0.6) ||
+          !diagnostics.typographyAudit.heroHeading?.fontFamily.includes('Plus Jakarta Sans') ||
+          diagnostics.typographyAudit.heroHeading.fontWeight !== '800' ||
+          diagnostics.typographyAudit.cardHeadings.length < 3 ||
+          diagnostics.typographyAudit.cardHeadings.some(heading =>
+            !heading.fontFamily.includes('Plus Jakarta Sans') ||
+            !['700', '800'].includes(heading.fontWeight) || heading.fontSize < 17) ||
           diagnostics.pageOverflowPx > 0 ||
           diagnostics.publishedCount !== 3 ||
           diagnostics.unpublishedCount !== 3 ||
diff --git a/src/components/landing/AboutSignal.astro b/src/components/landing/AboutSignal.astro
index 4ae5063c..c20f3f78 100644
--- a/src/components/landing/AboutSignal.astro
+++ b/src/components/landing/AboutSignal.astro
@@ -135,10 +135,10 @@ const proofPoints = [
     margin: 0 0 var(--space-4);
     color: var(--ink-display);
     font-family: var(--font-display);
-    font-size: clamp(1.75rem, 3.1vw, 2.95rem);
-    font-weight: 820;
-    letter-spacing: -0.042em;
-    line-height: 1.08;
+    font-size: var(--text-section-title);
+    font-weight: var(--weight-display);
+    letter-spacing: var(--tracking-section-title);
+    line-height: var(--leading-section-title);
     text-wrap: balance;
   }
 
@@ -150,14 +150,14 @@ const proofPoints = [
     max-width: 620px;
     margin: 0;
     color: var(--ink-muted);
-    font-size: clamp(1rem, 1.25vw, 1.12rem);
+    font-size: var(--text-section-intro);
     line-height: 1.6;
     text-wrap: pretty;
   }
 
   .about-summary strong {
     color: var(--ink-display);
-    font-weight: 720;
+    font-weight: var(--weight-heading);
   }
 
   .about-actions {
@@ -293,7 +293,7 @@ const proofPoints = [
     color: var(--accent-blue);
     font-family: var(--font-mono);
     font-size: var(--text-caption);
-    font-weight: 700;
+    font-weight: var(--weight-heading);
   }
 
   .proof-item h3 {
@@ -301,7 +301,7 @@ const proofPoints = [
     color: var(--ink-display);
     font-family: var(--font-display);
     font-size: 1rem;
-    font-weight: 780;
+    font-weight: var(--weight-display);
     line-height: 1.35;
   }
 
@@ -362,7 +362,7 @@ const proofPoints = [
     }
 
     .about-content h2 {
-      font-size: clamp(1.65rem, 8vw, 2.3rem);
+      font-size: var(--text-section-title-mobile);
     }
 
     .portrait-circle-wrapper {
@@ -403,6 +403,14 @@ const proofPoints = [
     }
   }
 
+  @media (max-width: 760px) {
+    .about-summary { font-size: var(--text-section-intro-mobile); }
+  }
+
+  @media (min-width: 681px) and (max-width: 760px) {
+    .about-content h2 { font-size: var(--text-section-title-mobile); }
+  }
+
   @media (prefers-reduced-motion: reduce) {
     .portrait-circle {
       transition: none;
diff --git a/src/components/landing/BuildSystemsShowcase.astro b/src/components/landing/BuildSystemsShowcase.astro
index 2c2d1f63..0a6f3535 100644
--- a/src/components/landing/BuildSystemsShowcase.astro
+++ b/src/components/landing/BuildSystemsShowcase.astro
@@ -187,7 +187,7 @@ const scopeFor = (id: string) =>
     margin: 0;
     font-family: var(--font-display);
     font-size: var(--text-caption);
-    font-weight: 800;
+    font-weight: var(--weight-display);
     letter-spacing: 0.11em;
     line-height: 1.4;
     text-transform: uppercase;
@@ -273,7 +273,7 @@ const scopeFor = (id: string) =>
     gap: 12px;
     color: var(--ink-subtle);
     font-size: var(--text-caption);
-    font-weight: 700;
+    font-weight: var(--weight-heading);
     line-height: 1.25;
   }
 
@@ -295,7 +295,7 @@ const scopeFor = (id: string) =>
     flex: 0 0 auto;
     color: var(--ink-subtle);
     font-size: var(--text-caption);
-    font-weight: 600;
+    font-weight: var(--weight-label);
     white-space: nowrap;
   }
 
@@ -333,8 +333,8 @@ const scopeFor = (id: string) =>
   .runtime-card__identity h4 {
     margin: 0;
     font-family: var(--font-display);
-    font-size: clamp(1.7rem, 3vw, 2.6rem);
-    font-weight: 800;
+    font-size: var(--text-feature-title);
+    font-weight: var(--weight-display);
     letter-spacing: -0.055em;
     line-height: 1.15;
     color: var(--ink-display);
@@ -344,7 +344,7 @@ const scopeFor = (id: string) =>
     margin: 0 0 9px;
     color: var(--ink-display);
     font-size: var(--text-body-sm);
-    font-weight: 700;
+    font-weight: var(--weight-heading);
     line-height: 1.45;
   }
 
@@ -415,7 +415,7 @@ const scopeFor = (id: string) =>
     color: var(--system-accent);
     font-family: var(--font-display);
     font-size: var(--text-caption);
-    font-weight: 750;
+    font-weight: var(--weight-heading);
     white-space: nowrap;
   }
 
@@ -500,8 +500,8 @@ const scopeFor = (id: string) =>
 
   .primitive__title {
     font-family: var(--font-display);
-    font-size: clamp(1.25rem, 2vw, 1.4rem);
-    font-weight: 800;
+    font-size: var(--text-card-title);
+    font-weight: var(--weight-display);
     letter-spacing: -0.045em;
     line-height: 1.2;
   }
@@ -517,7 +517,7 @@ const scopeFor = (id: string) =>
     margin-top: 9px;
     color: #b9cdec;
     font-size: var(--text-caption);
-    font-weight: 600;
+    font-weight: var(--weight-label);
     text-transform: capitalize;
   }
 
diff --git a/src/components/landing/DecisionTable.astro b/src/components/landing/DecisionTable.astro
index 5f0573db..b583b629 100644
--- a/src/components/landing/DecisionTable.astro
+++ b/src/components/landing/DecisionTable.astro
@@ -271,7 +271,7 @@ const modes: DeploymentMode[] = [
     margin: 0 0 8px;
     font-family: var(--font-display);
     font-size: var(--text-caption);
-    font-weight: 800;
+    font-weight: var(--weight-display);
     line-height: 1.35;
     letter-spacing: 0.08em;
   }
@@ -283,8 +283,8 @@ const modes: DeploymentMode[] = [
     margin: 0;
     max-width: 690px;
     font-family: var(--font-display);
-    font-size: clamp(1.14rem, 2.3vw, 1.55rem);
-    font-weight: 760;
+    font-size: var(--text-card-title);
+    font-weight: var(--weight-heading);
     letter-spacing: -0.036em;
     line-height: 1.22;
     color: var(--ink-display);
@@ -420,14 +420,14 @@ const modes: DeploymentMode[] = [
     color: var(--ink-display);
     font-family: var(--font-display);
     font-size: 1.08rem;
-    font-weight: 800;
+    font-weight: var(--weight-display);
     line-height: 1.2;
   }
 
   .card-eyebrow {
     color: var(--ink-subtle);
     font-size: var(--text-caption);
-    font-weight: 640;
+    font-weight: var(--weight-label);
     line-height: 1.3;
   }
 
@@ -436,7 +436,7 @@ const modes: DeploymentMode[] = [
     color: var(--ink-subtle);
     font-family: var(--font-mono);
     font-size: var(--text-caption);
-    font-weight: 620;
+    font-weight: var(--weight-label);
     white-space: nowrap;
   }
 
@@ -445,8 +445,8 @@ const modes: DeploymentMode[] = [
     max-width: 360px;
     color: var(--decision-ink);
     font-family: var(--font-display);
-    font-size: clamp(1.5rem, 3.3vw, 2rem);
-    font-weight: 830;
+    font-size: var(--text-feature-title);
+    font-weight: var(--weight-display);
     line-height: 1.13;
     letter-spacing: -0.048em;
     text-wrap: pretty;
@@ -487,7 +487,7 @@ const modes: DeploymentMode[] = [
 
   .factor dt {
     color: var(--ink-subtle);
-    font-weight: 540;
+    font-weight: var(--weight-medium);
   }
 
   .factor dd {
@@ -497,15 +497,15 @@ const modes: DeploymentMode[] = [
     min-width: 0;
     margin: 0;
     color: var(--ink);
-    font-weight: 650;
+    font-weight: var(--weight-label);
   }
 
   .factor .factor--strength {
     color: var(--mode-accent);
-    font-weight: 750;
+    font-weight: var(--weight-heading);
   }
 
-  .factor-check { flex: 0 0 auto; font-weight: 850; }
+  .factor-check { flex: 0 0 auto; font-weight: var(--weight-display); }
 
   .card-conclusion {
     flex: 0 0 auto;
@@ -525,7 +525,7 @@ const modes: DeploymentMode[] = [
     color: var(--ink-display);
     font-family: var(--font-display);
     font-size: var(--text-body-sm);
-    font-weight: 730;
+    font-weight: var(--weight-heading);
     line-height: 1.42;
   }
 
@@ -544,12 +544,12 @@ const modes: DeploymentMode[] = [
     color: var(--ink-subtle);
     font-family: var(--font-mono);
     font-size: var(--text-caption);
-    font-weight: 600;
+    font-weight: var(--weight-label);
   }
 
   .rail-position strong {
     color: var(--ink-display);
-    font-weight: 800;
+    font-weight: var(--weight-display);
   }
 
   .rail-buttons {
@@ -611,7 +611,7 @@ const modes: DeploymentMode[] = [
 
   .decision-transition strong {
     color: var(--ink-display);
-    font-weight: 750;
+    font-weight: var(--weight-heading);
   }
 
   .transition-link {
@@ -627,7 +627,7 @@ const modes: DeploymentMode[] = [
     color: var(--accent-blue-dark);
     font-family: var(--font-display);
     font-size: var(--text-caption);
-    font-weight: 770;
+    font-weight: var(--weight-heading);
     text-decoration: none;
     transition: background var(--duration-fast) ease;
   }
diff --git a/src/components/landing/EvidenceStage.astro b/src/components/landing/EvidenceStage.astro
index 5777dfcb..70c384dd 100644
--- a/src/components/landing/EvidenceStage.astro
+++ b/src/components/landing/EvidenceStage.astro
@@ -81,7 +81,7 @@ const experiments = measureStage.systems[0];
     color: var(--accent-blue-dark);
     font-family: var(--font-display);
     font-size: var(--text-caption);
-    font-weight: 820;
+    font-weight: var(--weight-display);
     letter-spacing: 0.075em;
     text-transform: uppercase;
   }
@@ -91,17 +91,17 @@ const experiments = measureStage.systems[0];
     margin: 0;
     color: var(--ink-display);
     font-family: var(--font-display);
-    font-size: clamp(1.8rem, 2.9vw, 2.75rem);
-    font-weight: 760;
-    letter-spacing: -0.032em;
-    line-height: 1.05;
+    font-size: var(--text-section-title);
+    font-weight: var(--weight-display);
+    letter-spacing: var(--tracking-section-title);
+    line-height: var(--leading-section-title);
   }
 
   .evidence-intro {
     max-width: 700px;
     margin: 12px 0 0;
     color: var(--ink-muted);
-    font-size: clamp(1rem, 1.1vw, 1.08rem);
+    font-size: var(--text-section-intro);
     line-height: 1.55;
   }
 
@@ -129,7 +129,7 @@ const experiments = measureStage.systems[0];
     color: var(--ink-display);
     font-family: var(--font-display);
     font-size: var(--text-caption);
-    font-weight: 780;
+    font-weight: var(--weight-display);
   }
 
   .experiments-toolbar__divider {
@@ -152,7 +152,7 @@ const experiments = measureStage.systems[0];
     color: var(--accent-blue-dark);
     font-family: var(--font-display);
     font-size: var(--text-caption);
-    font-weight: 740;
+    font-weight: var(--weight-heading);
     text-decoration: none;
   }
 
@@ -172,6 +172,11 @@ const experiments = measureStage.systems[0];
     }
   }
 
+  @media (max-width: 760px) {
+    .evidence-heading { font-size: var(--text-section-title-mobile); }
+    .evidence-intro { font-size: var(--text-section-intro-mobile); }
+  }
+
   @media (max-width: 540px) {
     .evidence-stage { padding: 43px 0 64px; }
 
@@ -187,8 +192,8 @@ const experiments = measureStage.systems[0];
       padding-right: 0;
     }
 
-    .evidence-heading { font-size: var(--text-h2); line-height: 1.16; }
-    .evidence-intro { font-size: var(--text-body-sm); line-height: 1.5; }
+    .evidence-heading { font-size: var(--text-section-title-mobile); line-height: var(--leading-section-title); }
+    .evidence-intro { font-size: var(--text-section-intro-mobile); line-height: 1.5; }
 
     .experiments-toolbar {
       align-items: center;
diff --git a/src/components/landing/ExperimentResultsExplorer.astro b/src/components/landing/ExperimentResultsExplorer.astro
index 5edca21c..137f6872 100644
--- a/src/components/landing/ExperimentResultsExplorer.astro
+++ b/src/components/landing/ExperimentResultsExplorer.astro
@@ -1452,7 +1452,7 @@ const selectorLabelFor = (track: Track) => {
     color: var(--accent-blue-dark);
     font-family: var(--font-display);
     font-size: var(--text-caption);
-    font-weight: 800;
+    font-weight: var(--weight-display);
     letter-spacing: 0.065em;
   }
 
@@ -1490,7 +1490,7 @@ const selectorLabelFor = (track: Track) => {
     padding: 6px 10px;
     white-space: nowrap;
     font-size: var(--text-caption);
-    font-weight: 720;
+    font-weight: var(--weight-heading);
   }
 
   .rg-dataset-picker {
@@ -1505,7 +1505,7 @@ const selectorLabelFor = (track: Track) => {
     cursor: pointer;
     font-family: var(--font-display);
     font-size: var(--text-caption);
-    font-weight: 700;
+    font-weight: var(--weight-heading);
     border-radius: var(--radius-full);
     border: 1px solid var(--border-medium);
     background: var(--surface-card);
@@ -1559,7 +1559,7 @@ const selectorLabelFor = (track: Track) => {
     color: var(--accent-blue-dark);
     font-family: var(--font-display);
     font-size: var(--text-caption);
-    font-weight: 760;
+    font-weight: var(--weight-heading);
     text-decoration: none;
   }
 
@@ -1575,7 +1575,7 @@ const selectorLabelFor = (track: Track) => {
     color: var(--ink-display);
     font-family: var(--font-display);
     font-size: clamp(2.6rem, 4vw, 3.2rem);
-    font-weight: 820;
+    font-weight: var(--weight-display);
     letter-spacing: -0.06em;
     line-height: 1;
   }
@@ -1622,14 +1622,14 @@ const selectorLabelFor = (track: Track) => {
     border-top: 2px solid color-mix(in srgb, var(--accent-blue) 32%, var(--border-subtle));
     color: var(--ink-display);
     font-family: var(--font-display);
-    font-weight: 760;
+    font-weight: var(--weight-heading);
     font-size: var(--text-caption);
   }
 
   .rg-metric-guide small {
     color: var(--ink-muted);
     margin-top: 4px;
-    font-weight: 450;
+    font-weight: var(--weight-medium);
     font-size: var(--text-caption);
     line-height: 1.45;
   }
@@ -1756,7 +1756,7 @@ const selectorLabelFor = (track: Track) => {
     background: transparent;
     color: var(--ink-muted);
     font-family: var(--font-display);
-    font-weight: 700;
+    font-weight: var(--weight-heading);
     font-size: var(--text-caption);
     white-space: nowrap;
     cursor: pointer;
@@ -1809,7 +1809,7 @@ const selectorLabelFor = (track: Track) => {
     color: var(--ink-muted);
     font-family: var(--font-display);
     font-size: var(--text-caption);
-    font-weight: 750;
+    font-weight: var(--weight-heading);
     background: var(--surface-subtle);
   }
 
@@ -1817,7 +1817,7 @@ const selectorLabelFor = (track: Track) => {
     min-width: 140px;
     color: var(--ink-display);
     font-family: var(--font-display);
-    font-weight: 760;
+    font-weight: var(--weight-heading);
     background: var(--surface-card);
   }
 
@@ -1915,7 +1915,7 @@ const selectorLabelFor = (track: Track) => {
     color: var(--accent-blue-dark);
     font-family: var(--font-display);
     font-size: var(--text-caption);
-    font-weight: 760;
+    font-weight: var(--weight-heading);
     white-space: nowrap;
     text-decoration: none;
   }
@@ -1941,7 +1941,7 @@ const selectorLabelFor = (track: Track) => {
     font-family: var(--font-display);
     font-size: 0.96rem;
     color: var(--ink-display);
-    font-weight: 780;
+    font-weight: var(--weight-display);
   }
 
   .jev-mcb-rows :global(.jev-mcb-row__model small) {
@@ -2059,7 +2059,7 @@ const selectorLabelFor = (track: Track) => {
     color: var(--ink-muted);
     font-family: var(--font-display);
     font-size: var(--text-caption);
-    font-weight: 780;
+    font-weight: var(--weight-display);
     letter-spacing: 0.07em;
   }
 
@@ -2081,7 +2081,7 @@ const selectorLabelFor = (track: Track) => {
     color: var(--ink-display);
     font-family: var(--font-display);
     font-size: 0.98rem;
-    font-weight: 750;
+    font-weight: var(--weight-heading);
   }
 
   .jev-coverage-banner p {
@@ -2150,7 +2150,7 @@ const selectorLabelFor = (track: Track) => {
     color: var(--ink-display);
     font-family: var(--font-display);
     font-size: clamp(1.5rem, 2.7vw, 2.15rem);
-    font-weight: 830;
+    font-weight: var(--weight-display);
     line-height: 1.13;
     letter-spacing: -0.045em;
   }
@@ -2184,7 +2184,7 @@ const selectorLabelFor = (track: Track) => {
     color: var(--ink-display);
     font-family: var(--font-display);
     font-size: clamp(1.05rem, 1.8vw, 1.35rem);
-    font-weight: 800;
+    font-weight: var(--weight-display);
     letter-spacing: -0.025em;
   }
 
@@ -2226,7 +2226,7 @@ const selectorLabelFor = (track: Track) => {
     padding: 0 16px 10px;
     color: var(--ink-muted);
     font-size: var(--text-caption);
-    font-weight: 720;
+    font-weight: var(--weight-heading);
   }
 
   .jev-ranking__columns > span:last-child {
@@ -2237,7 +2237,7 @@ const selectorLabelFor = (track: Track) => {
     display: block;
     color: var(--ink-subtle);
     font-size: var(--text-caption);
-    font-weight: 500;
+    font-weight: var(--weight-medium);
   }
 
   .jev-ranking__rows {
@@ -2263,7 +2263,7 @@ const selectorLabelFor = (track: Track) => {
     color: var(--ink-display);
     font-family: var(--font-display);
     font-size: 0.94rem;
-    font-weight: 780;
+    font-weight: var(--weight-display);
     line-height: 1.3;
   }
 
@@ -2449,7 +2449,7 @@ const selectorLabelFor = (track: Track) => {
   .experiment-tab__title {
     font-family: var(--font-display);
     font-size: var(--text-caption);
-    font-weight: 720;
+    font-weight: var(--weight-heading);
     white-space: nowrap;
   }
 
@@ -2513,7 +2513,7 @@ const selectorLabelFor = (track: Track) => {
     color: var(--accent-blue-dark);
     font-family: var(--font-display);
     font-size: 0.9rem;
-    font-weight: 800;
+    font-weight: var(--weight-display);
   }
 
   .evidence-panel__result {
@@ -2529,7 +2529,7 @@ const selectorLabelFor = (track: Track) => {
     color: var(--accent-blue-dark);
     font-family: var(--font-display);
     font-size: var(--text-caption);
-    font-weight: 800;
+    font-weight: var(--weight-display);
     letter-spacing: 0.055em;
   }
 
@@ -2568,7 +2568,7 @@ const selectorLabelFor = (track: Track) => {
     color: var(--ink-display);
     font-family: var(--font-display);
     font-size: clamp(1.55rem, 2.5vw, 2.15rem);
-    font-weight: 840;
+    font-weight: var(--weight-display);
     letter-spacing: -0.045em;
     line-height: 1.06;
   }
@@ -2589,7 +2589,7 @@ const selectorLabelFor = (track: Track) => {
     color: var(--accent-blue-dark);
     font-family: var(--font-display);
     font-size: var(--text-caption);
-    font-weight: 760;
+    font-weight: var(--weight-heading);
     text-decoration: none;
   }
 
@@ -2611,7 +2611,7 @@ const selectorLabelFor = (track: Track) => {
   .run-summary strong {
     color: var(--ink-display);
     font-family: var(--font-display);
-    font-weight: 760;
+    font-weight: var(--weight-heading);
   }
 
   .benchmark-story {
@@ -2648,7 +2648,7 @@ const selectorLabelFor = (track: Track) => {
     color: var(--ink-subtle);
     font-family: var(--font-display);
     font-size: var(--text-caption);
-    font-weight: 760;
+    font-weight: var(--weight-heading);
     letter-spacing: 0.045em;
   }
 
@@ -2694,7 +2694,7 @@ const selectorLabelFor = (track: Track) => {
     color: var(--ink-muted);
     font-family: var(--font-display);
     font-size: var(--text-caption);
-    font-weight: 700;
+    font-weight: var(--weight-heading);
     cursor: pointer;
   }
 
@@ -2742,7 +2742,7 @@ const selectorLabelFor = (track: Track) => {
   .plot-selection__eyebrow {
     color: var(--ink-subtle);
     font-size: var(--text-caption);
-    font-weight: 760;
+    font-weight: var(--weight-heading);
     letter-spacing: 0.06em;
   }
 
@@ -2818,7 +2818,7 @@ const selectorLabelFor = (track: Track) => {
     fill: var(--ink-muted);
     font-family: var(--font-display);
     font-size: var(--text-caption);
-    font-weight: 650;
+    font-weight: var(--weight-label);
   }
 
   .plot-legend {
@@ -2913,7 +2913,7 @@ const selectorLabelFor = (track: Track) => {
     color: var(--ink-display);
     font-family: var(--font-display);
     font-size: clamp(1.35rem, 2.2vw, 1.75rem);
-    font-weight: 830;
+    font-weight: var(--weight-display);
     letter-spacing: -0.04em;
   }
 
@@ -2943,7 +2943,7 @@ const selectorLabelFor = (track: Track) => {
     color: var(--ink-display);
     font-family: var(--font-display);
     font-size: 1rem;
-    font-weight: 780;
+    font-weight: var(--weight-display);
     line-height: 1.4;
   }
 
@@ -3039,15 +3039,15 @@ const selectorLabelFor = (track: Track) => {
     color: var(--accent-blue);
     font-family: var(--font-display);
     font-size: var(--text-caption);
-    font-weight: 740;
+    font-weight: var(--weight-heading);
     letter-spacing: .045em;
   }
   .experiment-index-heading h3 {
     margin: 5px 0 0;
     color: var(--ink-display);
     font-family: var(--font-display);
-    font-size: var(--text-h3);
-    font-weight: 760;
+    font-size: var(--text-card-title);
+    font-weight: var(--weight-heading);
     letter-spacing: -.025em;
     line-height: 1.25;
   }
@@ -3110,7 +3110,7 @@ const selectorLabelFor = (track: Track) => {
       gap: 4px 12px;
       margin-bottom: 12px;
     }
-    .experiment-index-heading h3 { font-size: 1.13rem; }
+    .experiment-index-heading h3 { font-size: var(--text-card-title); }
     .experiment-selector-wrap { margin-bottom: 15px; }
     .experiment-selector-wrap::after { display: none; }
 
@@ -3166,7 +3166,7 @@ const selectorLabelFor = (track: Track) => {
       margin: 8px 0 6px;
       font-family: var(--font-display);
       font-size: clamp(1.2rem, 5vw, 1.45rem);
-      font-weight: 760;
+      font-weight: var(--weight-heading);
       line-height: 1.2;
       letter-spacing: -.028em;
     }
@@ -3222,7 +3222,7 @@ const selectorLabelFor = (track: Track) => {
     .highlight strong {
       margin-top: 5px;
       font-size: clamp(1.13rem, 4.4vw, 1.38rem);
-      font-weight: 760;
+      font-weight: var(--weight-heading);
       letter-spacing: -.025em;
       overflow-wrap: anywhere;
     }
@@ -3322,14 +3322,14 @@ const selectorLabelFor = (track: Track) => {
     color: var(--accent-blue);
     font-family: var(--font-display);
     font-size: var(--text-caption);
-    font-weight: 720;
+    font-weight: var(--weight-heading);
     letter-spacing: .04em;
   }
   .mcb-model-browser__heading h4 {
     margin: 6px 0;
     font-family: var(--font-display);
-    font-size: var(--text-h3);
-    font-weight: 760;
+    font-size: var(--text-card-title);
+    font-weight: var(--weight-heading);
     letter-spacing: -.025em;
     line-height: 1.3;
     color: var(--ink-display);
@@ -3360,7 +3360,7 @@ const selectorLabelFor = (track: Track) => {
     color: var(--ink-muted);
     font-family: var(--font-display);
     font-size: var(--text-caption);
-    font-weight: 690;
+    font-weight: var(--weight-heading);
     cursor: pointer;
   }
   .mcb-list-filters button[aria-pressed='true'] {
@@ -3411,7 +3411,7 @@ const selectorLabelFor = (track: Track) => {
     color: var(--ink-display);
     font-family: var(--font-display);
     font-size: var(--text-body-sm);
-    font-weight: 720;
+    font-weight: var(--weight-heading);
     line-height: 1.35;
     overflow-wrap: anywhere;
   }
@@ -3434,7 +3434,7 @@ const selectorLabelFor = (track: Track) => {
   }
   .mcb-model-cards :global(.mcb-model-card__metrics span:first-child) {
     color: var(--ink-display);
-    font-weight: 700;
+    font-weight: var(--weight-heading);
   }
   .mcb-show-all {
     width: 100%;
@@ -3447,7 +3447,7 @@ const selectorLabelFor = (track: Track) => {
     color: var(--accent-blue-dark);
     font-family: var(--font-display);
     font-size: var(--text-caption);
-    font-weight: 730;
+    font-weight: var(--weight-heading);
     cursor: pointer;
   }
   .mcb-show-all[hidden] { display: none; }
@@ -3480,7 +3480,7 @@ const selectorLabelFor = (track: Track) => {
     display: block;
     font-family: var(--font-display);
     font-size: var(--text-body-sm);
-    font-weight: 720;
+    font-weight: var(--weight-heading);
     color: var(--ink-display);
   }
   .mcb-chart-details > summary small, .mcb-method-details > summary small {
@@ -3524,7 +3524,7 @@ const selectorLabelFor = (track: Track) => {
       color: var(--accent-blue);
       font-family: var(--font-display);
       font-size: var(--text-caption);
-      font-weight: 730;
+      font-weight: var(--weight-heading);
       letter-spacing: .04em;
     }
     .experiment-mobile-chooser select {
@@ -3539,7 +3539,7 @@ const selectorLabelFor = (track: Track) => {
       color: var(--ink-display);
       font-family: var(--font-display);
       font-size: var(--text-body-sm);
-      font-weight: 690;
+      font-weight: var(--weight-heading);
       text-overflow: ellipsis;
       cursor: pointer;
     }
@@ -3612,7 +3612,7 @@ const selectorLabelFor = (track: Track) => {
     .mcb-story .highlight:last-child { grid-column: 1/-1; }
     .mcb-story .highlight strong { font-size: clamp(1.12rem, 4.7vw, 1.36rem); }
     .mcb-model-browser { margin-top: 22px; }
-    .mcb-model-browser__heading h4 { font-size: 1.125rem; }
+    .mcb-model-browser__heading h4 { font-size: var(--text-card-title); }
     .mcb-model-cards { grid-template-columns: 1fr; gap: 8px; }
     .mcb-model-cards :global(.mcb-model-card) { min-height: 83px; padding: 12px; gap: 8px; }
     .mcb-model-cards :global(.mcb-model-card__top) { flex-wrap: nowrap; }
@@ -3650,8 +3650,8 @@ const selectorLabelFor = (track: Track) => {
     }
     .experiment-index-heading h3 {
       font-family: var(--font-display);
-      font-size: 1.13rem;
-      font-weight: 750;
+      font-size: var(--text-card-title);
+      font-weight: var(--weight-heading);
       letter-spacing: -.02em;
     }
     .experiment-index-heading__count { white-space: nowrap; }
@@ -3665,7 +3665,7 @@ const selectorLabelFor = (track: Track) => {
       color: var(--ink-subtle);
       font-family: var(--font-display);
       font-size: var(--text-caption);
-      font-weight: 680;
+      font-weight: var(--weight-heading);
     }
     .experiment-rail-guide > span > span { color: var(--accent-blue); }
     .experiment-rail-actions {
@@ -3678,7 +3678,7 @@ const selectorLabelFor = (track: Track) => {
       min-width: 59px;
       font-family: var(--font-mono);
       font-size: var(--text-caption);
-      font-weight: 690;
+      font-weight: var(--weight-heading);
       color: var(--ink-muted);
       font-variant-numeric: tabular-nums;
     }
@@ -3760,7 +3760,7 @@ const selectorLabelFor = (track: Track) => {
     .experiment-tab__title {
       font-family: var(--font-display);
       font-size: var(--text-body);
-      font-weight: 740;
+      font-weight: var(--weight-heading);
       line-height: 1.25;
       letter-spacing: -.025em;
       overflow-wrap: anywhere;
@@ -3769,7 +3769,7 @@ const selectorLabelFor = (track: Track) => {
       display: block;
       font-family: var(--font-body);
       font-size: var(--text-caption);
-      font-weight: 650;
+      font-weight: var(--weight-label);
       color: var(--accent-teal);
     }
     .experiment-tab[data-published='false'] .experiment-tab__availability {
@@ -3825,7 +3825,7 @@ const selectorLabelFor = (track: Track) => {
     .run-summary > span strong {
       font-family: var(--font-display);
       font-size: clamp(1.35rem, 5.2vw, 1.65rem);
-      font-weight: 790;
+      font-weight: var(--weight-display);
       line-height: 1.18;
       color: var(--ink-display);
     }
@@ -3889,7 +3889,7 @@ const selectorLabelFor = (track: Track) => {
       color: var(--ink-display);
       font-family: var(--font-display);
       font-size: clamp(1.45rem, 6vw, 1.75rem);
-      font-weight: 780;
+      font-weight: var(--weight-display);
       letter-spacing: -.025em;
     }
     .mcb-story .highlight small {
@@ -3944,7 +3944,7 @@ const selectorLabelFor = (track: Track) => {
     .mcb-model-cards :global(.mcb-model-card__top strong) {
       font-family: var(--font-display);
       font-size: var(--text-body);
-      font-weight: 780;
+      font-weight: var(--weight-display);
     }
     .mcb-model-cards :global(.mcb-model-card__metrics) {
       display: grid;
@@ -3962,7 +3962,7 @@ const selectorLabelFor = (track: Track) => {
       overflow-wrap: anywhere;
     }
     .mcb-model-cards :global(.mcb-model-card__metrics span:first-child) {
-      font-weight: 800;
+      font-weight: var(--weight-display);
       font-size: 1.05rem;
       color: var(--ink-display);
     }
@@ -4017,7 +4017,7 @@ const selectorLabelFor = (track: Track) => {
     color: var(--accent-blue-dark);
     font-family: var(--font-display);
     font-size: var(--text-caption);
-    font-weight: 770;
+    font-weight: var(--weight-heading);
     letter-spacing: .025em;
     line-height: 1.25;
     overflow-wrap: anywhere;
@@ -4031,7 +4031,7 @@ const selectorLabelFor = (track: Track) => {
     color: var(--ink-muted);
     font-family: var(--font-body);
     font-size: var(--text-caption);
-    font-weight: 660;
+    font-weight: var(--weight-label);
     line-height: 1.35;
   }
   .mcb-model-cards :global(.mcb-model-card__identity) {
@@ -4045,8 +4045,8 @@ const selectorLabelFor = (track: Track) => {
     max-width: 100%;
     color: var(--ink-display);
     font-family: var(--font-display);
-    font-size: 1.13rem;
-    font-weight: 770;
+    font-size: var(--text-card-title);
+    font-weight: var(--weight-heading);
     letter-spacing: -.025em;
     line-height: 1.22;
     overflow-wrap: anywhere;
@@ -4056,7 +4056,7 @@ const selectorLabelFor = (track: Track) => {
     color: var(--ink-muted);
     font-family: var(--font-body);
     font-size: var(--text-caption);
-    font-weight: 460;
+    font-weight: var(--weight-body);
     line-height: 1.38;
     text-wrap: pretty;
   }
@@ -4079,11 +4079,11 @@ const selectorLabelFor = (track: Track) => {
     color: var(--ink-display);
     font-family: var(--font-body);
     font-size: var(--text-caption);
-    font-weight: 500;
+    font-weight: var(--weight-medium);
     line-height: 1.25;
   }
   .mcb-model-cards :global(.mcb-model-card__metrics > .mcb-model-card__metric:first-child) {
-    font-weight: 500;
+    font-weight: var(--weight-medium);
     font-size: var(--text-caption);
   }
   .mcb-model-cards :global(.mcb-model-card__metric-value) {
@@ -4091,7 +4091,7 @@ const selectorLabelFor = (track: Track) => {
     color: var(--ink-display);
     font-family: var(--font-display);
     font-size: clamp(1.07rem, 1.6vw, 1.25rem);
-    font-weight: 800;
+    font-weight: var(--weight-display);
     line-height: 1.17;
     letter-spacing: -.025em;
     white-space: nowrap;
@@ -4102,7 +4102,7 @@ const selectorLabelFor = (track: Track) => {
     color: var(--ink-muted);
     font-family: var(--font-body);
     font-size: var(--text-caption);
-    font-weight: 500;
+    font-weight: var(--weight-medium);
     line-height: 1.3;
   }
   .mcb-model-cards :global(.mcb-model-card[aria-pressed='true']) {
@@ -4118,7 +4118,7 @@ const selectorLabelFor = (track: Track) => {
       color: var(--ink-subtle);
       font-family: var(--font-display);
       font-size: var(--text-caption);
-      font-weight: 680;
+      font-weight: var(--weight-heading);
     }
     .mcb-model-browser__swipe span { color: var(--accent-blue); }
     .mcb-model-cards :global(.mcb-model-entry) {
diff --git a/src/components/landing/LandingHeader.astro b/src/components/landing/LandingHeader.astro
index c14a1beb..bad63d1e 100644
--- a/src/components/landing/LandingHeader.astro
+++ b/src/components/landing/LandingHeader.astro
@@ -173,7 +173,7 @@ const resolveHref = (href: string) => {
   .brand-name {
     font-family: var(--font-display);
     font-size: var(--text-caption);
-    font-weight: 850;
+    font-weight: var(--weight-display);
     letter-spacing: 0.045em;
     text-transform: uppercase;
     color: var(--ink-display);
@@ -183,7 +183,7 @@ const resolveHref = (href: string) => {
   .brand-role {
     color: var(--ink-muted);
     font-size: var(--text-caption);
-    font-weight: 620;
+    font-weight: var(--weight-label);
     line-height: 1.4;
     white-space: nowrap;
   }
@@ -211,7 +211,7 @@ const resolveHref = (href: string) => {
     color: var(--ink);
     text-decoration: none;
     font-size: var(--text-caption);
-    font-weight: 650;
+    font-weight: var(--weight-label);
     transition: color var(--duration-fast) ease;
   }
 
diff --git a/src/components/landing/LandingHero.astro b/src/components/landing/LandingHero.astro
index 4ceeec08..9a156280 100644
--- a/src/components/landing/LandingHero.astro
+++ b/src/components/landing/LandingHero.astro
@@ -135,7 +135,7 @@ const linkedinUrl = hero.identity.socials?.find((link) => link.platform === 'lin
     font-size: clamp(1.85rem, 4.35vw, 4.35rem);
     line-height: 1.1;
     letter-spacing: -0.055em;
-    font-weight: 860;
+    font-weight: var(--weight-display);
     color: var(--ink-display);
     white-space: nowrap;
   }
@@ -167,7 +167,7 @@ const linkedinUrl = hero.identity.socials?.find((link) => link.platform === 'lin
     font-family: var(--font-display);
     font-size: clamp(1.32rem, 2.15vw, 2rem);
     line-height: 1.24;
-    font-weight: 760;
+    font-weight: var(--weight-heading);
     letter-spacing: -0.025em;
     color: var(--ink-display);
   }
@@ -182,7 +182,7 @@ const linkedinUrl = hero.identity.socials?.find((link) => link.platform === 'lin
 
   .hero-explanation :global(strong) {
     color: var(--ink-display);
-    font-weight: 740;
+    font-weight: var(--weight-heading);
   }
 
   .hero-position {
@@ -193,7 +193,7 @@ const linkedinUrl = hero.identity.socials?.find((link) => link.platform === 'lin
     margin: 0;
     font-family: var(--font-display);
     font-size: 0.9rem;
-    font-weight: 700;
+    font-weight: var(--weight-heading);
     color: var(--ink);
   }
 
@@ -241,7 +241,7 @@ const linkedinUrl = hero.identity.socials?.find((link) => link.platform === 'lin
     color: var(--accent-blue);
     font-family: var(--font-mono);
     font-size: var(--text-caption);
-    font-weight: 800;
+    font-weight: var(--weight-display);
     line-height: 1.5;
   }
 
@@ -285,7 +285,7 @@ const linkedinUrl = hero.identity.socials?.find((link) => link.platform === 'lin
 
   .trust-role {
     color: var(--ink);
-    font-weight: 690;
+    font-weight: var(--weight-heading);
   }
 
   .hero-trust a {
@@ -293,7 +293,7 @@ const linkedinUrl = hero.identity.socials?.find((link) => link.platform === 'lin
     align-items: center;
     gap: 5px;
     color: var(--ink-muted);
-    font-weight: 650;
+    font-weight: var(--weight-label);
     text-decoration: none;
     transition: color var(--duration-fast) ease;
   }
diff --git a/src/components/landing/LoopClosure.astro b/src/components/landing/LoopClosure.astro
index 67035c33..92c23723 100644
--- a/src/components/landing/LoopClosure.astro
+++ b/src/components/landing/LoopClosure.astro
@@ -84,7 +84,7 @@ const { loopClosure } = landingData;
     font-size: clamp(1.85rem, 3.2vw, 2.65rem);
     line-height: 1.12;
     letter-spacing: -0.035em;
-    font-weight: 800;
+    font-weight: var(--weight-display);
     color: var(--ink-display);
   }
 
@@ -113,14 +113,14 @@ const { loopClosure } = landingData;
   .track-step {
     font-family: var(--font-display);
     font-size: var(--text-badge);
-    font-weight: 800;
+    font-weight: var(--weight-display);
     color: var(--ink-muted);
     letter-spacing: 0.06em;
   }
 
   .track-step--final {
     color: var(--accent-blue-dark);
-    font-weight: 850;
+    font-weight: var(--weight-display);
     background: var(--surface-blue-subtle);
     padding: 3px 10px;
     border-radius: var(--radius-full);
@@ -128,7 +128,7 @@ const { loopClosure } = landingData;
 
   .track-arrow {
     color: var(--accent-blue);
-    font-weight: 800;
+    font-weight: var(--weight-display);
     font-size: var(--text-badge);
   }
 
@@ -137,7 +137,7 @@ const { loopClosure } = landingData;
     font-family: var(--font-display);
     font-size: var(--text-caption);
     color: var(--accent-blue-dark);
-    font-weight: 750;
+    font-weight: var(--weight-heading);
     letter-spacing: 0.02em;
   }
 
@@ -187,7 +187,7 @@ const { loopClosure } = landingData;
   .outcome-label {
     font-family: var(--font-display);
     font-size: var(--text-body);
-    font-weight: 850;
+    font-weight: var(--weight-display);
     letter-spacing: 0.05em;
     color: var(--ink-display);
   }
diff --git a/src/components/landing/MethodThread.astro b/src/components/landing/MethodThread.astro
index ad0de326..35a2ec4e 100644
--- a/src/components/landing/MethodThread.astro
+++ b/src/components/landing/MethodThread.astro
@@ -146,7 +146,7 @@ const pathD = direction === 'ltr'
   .pill-label {
     font-family: var(--font-display);
     font-size: var(--text-caption);
-    font-weight: 800;
+    font-weight: var(--weight-display);
     letter-spacing: 0.055em;
     color: var(--accent-blue-dark);
   }
diff --git a/src/components/landing/PlaneTemplate.astro b/src/components/landing/PlaneTemplate.astro
index 74fc66ac..091a1ba7 100644
--- a/src/components/landing/PlaneTemplate.astro
+++ b/src/components/landing/PlaneTemplate.astro
@@ -115,10 +115,10 @@ const titleId = `${id}-title`;
     max-width: 100%;
     margin: 0 0 var(--space-3);
     font-family: var(--font-display);
-    font-size: clamp(1.75rem, 3.1vw, 2.95rem);
-    line-height: 1.08;
-    letter-spacing: -0.042em;
-    font-weight: 820;
+    font-size: var(--text-section-title);
+    line-height: var(--leading-section-title);
+    letter-spacing: var(--tracking-section-title);
+    font-weight: var(--weight-display);
     color: var(--ink-display);
     text-wrap: pretty;
   }
@@ -126,7 +126,7 @@ const titleId = `${id}-title`;
   .plane-intro .stage-intro {
     max-width: 680px;
     margin: 0;
-    font-size: clamp(1rem, 1.25vw, 1.12rem);
+    font-size: var(--text-section-intro);
     line-height: 1.6;
     color: var(--ink-muted);
     text-wrap: pretty;
@@ -157,7 +157,6 @@ const titleId = `${id}-title`;
     .plane-section.stage-left .plane-intro,
     .plane-section.stage-right .plane-intro { align-self: flex-start; }
 
-    .plane-intro .stage-heading { font-size: clamp(1.65rem, 5vw, 2.35rem); }
   }
 
   @media (max-width: 760px) {
@@ -166,8 +165,8 @@ const titleId = `${id}-title`;
       padding-right: 12px;
     }
 
-    .plane-intro .stage-heading { font-size: clamp(1.45rem, 6vw, 1.95rem); }
-    .plane-intro .stage-intro { font-size: 0.98rem; }
+    .plane-intro .stage-heading { font-size: var(--text-section-title-mobile); }
+    .plane-intro .stage-intro { font-size: var(--text-section-intro-mobile); }
   }
 
   @media (max-width: 540px) {
diff --git a/src/components/landing/StageRail.astro b/src/components/landing/StageRail.astro
index e188e3f4..941cc1da 100644
--- a/src/components/landing/StageRail.astro
+++ b/src/components/landing/StageRail.astro
@@ -77,7 +77,7 @@ const label = String(number).padStart(2, '0');
       0 12px 30px rgba(8, 19, 51, 0.16);
     font-family: var(--font-display);
     font-size: var(--text-caption);
-    font-weight: 800;
+    font-weight: var(--weight-display);
     letter-spacing: 0.04em;
     opacity: var(--node-opacity, 0);
     transition:
diff --git a/src/components/landing/TestProductGallery.astro b/src/components/landing/TestProductGallery.astro
index 645620f4..edf8ee23 100644
--- a/src/components/landing/TestProductGallery.astro
+++ b/src/components/landing/TestProductGallery.astro
@@ -214,7 +214,7 @@ const applicationId = (name: string) =>
     margin: 0;
     font-family: var(--font-display);
     font-size: var(--text-caption);
-    font-weight: 720;
+    font-weight: var(--weight-heading);
     line-height: 1.35;
     letter-spacing: 0.045em;
   }
@@ -225,8 +225,8 @@ const applicationId = (name: string) =>
     max-width: 720px;
     color: var(--ink-display);
     font-family: var(--font-display);
-    font-size: var(--text-h3);
-    font-weight: 760;
+    font-size: var(--text-card-title);
+    font-weight: var(--weight-heading);
     letter-spacing: -0.025em;
     line-height: 1.26;
   }
@@ -350,7 +350,7 @@ const applicationId = (name: string) =>
     color: var(--ink-display);
     font-family: var(--font-display);
     font-size: 1.0625rem;
-    font-weight: 760;
+    font-weight: var(--weight-heading);
     letter-spacing: -0.018em;
     line-height: 1.2;
   }
@@ -358,7 +358,7 @@ const applicationId = (name: string) =>
     color: var(--product-accent);
     font-family: var(--font-body);
     font-size: var(--text-caption);
-    font-weight: 650;
+    font-weight: var(--weight-label);
     line-height: 1.28;
     letter-spacing: 0;
   }
@@ -375,8 +375,8 @@ const applicationId = (name: string) =>
     margin: var(--space-4) 0 var(--space-2);
     color: var(--ink-display);
     font-family: var(--font-display);
-    font-size: clamp(1.25rem, 1.85vw, 1.5rem);
-    font-weight: 760;
+    font-size: var(--text-card-title);
+    font-weight: var(--weight-heading);
     line-height: 1.21;
     letter-spacing: -0.028em;
     text-wrap: pretty;
@@ -386,7 +386,7 @@ const applicationId = (name: string) =>
     color: var(--ink-muted);
     font-family: var(--font-body);
     font-size: var(--text-body-sm);
-    font-weight: 450;
+    font-weight: var(--weight-medium);
     line-height: 1.45;
     text-wrap: pretty;
   }
@@ -463,7 +463,7 @@ const applicationId = (name: string) =>
     color: var(--ink);
     font-family: var(--font-body);
     font-size: var(--text-caption);
-    font-weight: 550;
+    font-weight: var(--weight-label);
     line-height: 1.3;
   }
 
@@ -484,12 +484,12 @@ const applicationId = (name: string) =>
     gap: 2px;
     min-width: 0;
   }
-  .runtime-label { color: var(--ink-subtle); font-size: var(--text-caption); font-weight: 650; letter-spacing: 0; }
+  .runtime-label { color: var(--ink-subtle); font-size: var(--text-caption); font-weight: var(--weight-label); letter-spacing: 0; }
   .runtime-link strong {
     color: var(--ink-display);
     font-family: var(--font-body);
     font-size: var(--text-caption);
-    font-weight: 650;
+    font-weight: var(--weight-label);
     line-height: 1.3;
   }
   .explore-link {
@@ -499,7 +499,7 @@ const applicationId = (name: string) =>
     color: var(--product-accent);
     font-family: var(--font-display);
     font-size: var(--text-caption);
-    font-weight: 730;
+    font-weight: var(--weight-heading);
   }
   .explore-link span { font-size: 18px; }
 
@@ -511,8 +511,8 @@ const applicationId = (name: string) =>
     gap: var(--space-3);
     margin-top: var(--space-2);
   }
-  .gallery-count { margin: 0; color: var(--ink-subtle); font-family: var(--font-mono); font-size: var(--text-caption); font-weight: 650; }
-  .gallery-count strong { color: var(--ink-display); font-weight: 800; }
+  .gallery-count { margin: 0; color: var(--ink-subtle); font-family: var(--font-mono); font-size: var(--text-caption); font-weight: var(--weight-label); }
+  .gallery-count strong { color: var(--ink-display); font-weight: var(--weight-display); }
   .gallery-buttons { display: flex; align-items: center; gap: var(--space-2); }
   .gallery-buttons button {
     display: grid;
@@ -553,7 +553,7 @@ const applicationId = (name: string) =>
     font-size: var(--text-body-sm);
     line-height: 1.5;
   }
-  .gallery-handoff strong { color: var(--ink-display); font-weight: 700; }
+  .gallery-handoff strong { color: var(--ink-display); font-weight: var(--weight-heading); }
   .handoff-link {
     display: inline-flex;
     align-items: center;
@@ -568,7 +568,7 @@ const applicationId = (name: string) =>
     text-decoration: none;
     font-family: var(--font-display);
     font-size: var(--text-caption);
-    font-weight: 740;
+    font-weight: var(--weight-heading);
   }
   .handoff-link:hover { background: var(--surface-blue-subtle); }
   .handoff-link span { font-size: 19px; }
diff --git a/src/components/layout/SiteFooter.astro b/src/components/layout/SiteFooter.astro
index 6b8aea35..35510704 100644
--- a/src/components/layout/SiteFooter.astro
+++ b/src/components/layout/SiteFooter.astro
@@ -108,7 +108,7 @@ const baseUrl = import.meta.env.BASE_URL.replace(/\/$/, '');
   .brand-name {
     font-family: var(--font-display);
     font-size: var(--text-caption);
-    font-weight: 700;
+    font-weight: var(--weight-heading);
     letter-spacing: -0.01em;
     color: var(--ink-display);
     transition: color var(--duration-fast) ease;
@@ -140,7 +140,7 @@ const baseUrl = import.meta.env.BASE_URL.replace(/\/$/, '');
     text-decoration: none;
     color: var(--ink-muted);
     font-size: var(--text-caption);
-    font-weight: 500;
+    font-weight: var(--weight-medium);
     transition: color var(--duration-fast) ease;
   }
 
diff --git a/src/components/layout/SiteHeader.astro b/src/components/layout/SiteHeader.astro
index 5877d89d..f47601a7 100644
--- a/src/components/layout/SiteHeader.astro
+++ b/src/components/layout/SiteHeader.astro
@@ -144,7 +144,7 @@ function getHref(href: string) {
   .brand-name {
     font-family: var(--font-display);
     font-size: var(--text-caption);
-    font-weight: 760;
+    font-weight: var(--weight-heading);
     letter-spacing: -0.012em;
     color: var(--ink-display);
     white-space: nowrap;
@@ -153,7 +153,7 @@ function getHref(href: string) {
   .brand-role {
     font-family: var(--font-body);
     font-size: var(--text-caption);
-    font-weight: 500;
+    font-weight: var(--weight-medium);
     color: var(--ink-muted);
     white-space: nowrap;
   }
@@ -192,7 +192,7 @@ function getHref(href: string) {
 
   .nav-link-text {
     font-size: var(--text-caption);
-    font-weight: 580;
+    font-weight: var(--weight-label);
     letter-spacing: -0.015em;
     line-height: 1.15;
     white-space: nowrap;
@@ -250,7 +250,7 @@ function getHref(href: string) {
     padding: 8px 13px;
     border-radius: var(--radius-full);
     font-size: var(--text-caption);
-    font-weight: 670;
+    font-weight: var(--weight-heading);
     white-space: nowrap;
     cursor: pointer;
     display: inline-flex;
@@ -362,7 +362,7 @@ function getHref(href: string) {
 
     .nav-link-text {
       font-size: 0.92rem;
-      font-weight: 600;
+      font-weight: var(--weight-label);
       text-align: left;
     }
 
diff --git a/src/layouts/BaseLayout.astro b/src/layouts/BaseLayout.astro
index aabab1ba..d44f18f3 100644
--- a/src/layouts/BaseLayout.astro
+++ b/src/layouts/BaseLayout.astro
@@ -127,7 +127,7 @@ const allSchemas = jsonLd
   <!-- Google Fonts: Plus Jakarta Sans & Inter (Modern Sans-Serif) -->
   <link rel="preconnect" href="https://fonts.googleapis.com">
   <link rel="preconnect" href="https://fonts.gstatic.com" crossorigin>
-  <link href="https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600&family=Plus+Jakarta+Sans:ital,wght@0,500;0,600;0,700;0,800;1,500;1,600&display=swap" rel="stylesheet">
+  <link href="https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700;800&family=Plus+Jakarta+Sans:ital,wght@0,500;0,600;0,700;0,800;1,500;1,600&display=swap" rel="stylesheet">
 
   <!-- Anti-flash inline theme initialization -->
   <script is:inline>
diff --git a/src/styles/tokens.css b/src/styles/tokens.css
index 98771c41..9a4a050f 100644
--- a/src/styles/tokens.css
+++ b/src/styles/tokens.css
@@ -62,6 +62,26 @@
   --text-badge: 0.875rem;
   /* 14px - badges and compact metadata remain readable */
 
+  /* Canonical homepage typographic roles.
+     Section titles match across DECIDE, BUILD, TEST and MEASURE; only the Hero
+     uses a larger display role. Keep typography predictable at phone widths. */
+  --text-section-title: clamp(1.75rem, 3.1vw, 2.95rem);
+  --text-section-title-mobile: clamp(1.6rem, 6.8vw, 2.1rem);
+  --text-section-intro: clamp(1rem, 1.25vw, 1.12rem);
+  --text-section-intro-mobile: var(--text-body);
+  --text-card-title: clamp(1.2rem, 1.75vw, 1.5rem);
+  --text-feature-title: clamp(1.45rem, 2.6vw, 2.1rem);
+  --text-card-body: var(--text-body-sm);
+  --text-kpi: clamp(1.15rem, 2vw, 1.55rem);
+
+  --weight-body: 400;
+  --weight-medium: 500;
+  --weight-label: 600;
+  --weight-heading: 700;
+  --weight-display: 800;
+  --leading-section-title: 1.12;
+  --tracking-section-title: -0.04em;
+
   /* Compatibility aliases for existing project modules.
      These resolve through the canonical scale above so older modules cannot
      silently fall back to browser defaults or sub-14px typography. */
diff --git a/tests/home-experience-contract.test.mjs b/tests/home-experience-contract.test.mjs
index 703ce454..fb9be143 100644
--- a/tests/home-experience-contract.test.mjs
+++ b/tests/home-experience-contract.test.mjs
@@ -180,7 +180,7 @@ test('TEST is a mobile-first gallery of actual project assets and product value'
   assert.match(gallery, /class="card-footer"/);
   assert.match(gallery, /class="preview-chrome"/);
   assert.doesNotMatch(gallery, /ACTUAL PRODUCT INTERFACE|CONNECTED INFRASTRUCTURE|class="infrastructure-link"/);
-  for (const token of ['--font-display', '--font-body', '--text-h3', '--text-body-sm', '--text-caption',
+  for (const token of ['--font-display', '--font-body', '--text-card-title', '--text-body-sm', '--text-caption',
     '--radius-lg', '--surface-card', '--border-medium', '--ink-display']) {
     assert.ok(gallery.includes('var(' + token + ')'), 'TEST must consume brand token ' + token);
   }
@@ -228,7 +228,7 @@ test('MEASURE is published-first and preserves all evidence provenance on mobile
   assert.match(stage, /<StageRail number=\{4\} side="right" isFinal \/>/);
   assert.match(stage, /<ExperimentResultsExplorer tracks=\{experiments\.tracks \|\| \[\]\} \/>/);
   assert.match(stage, /--font-display/);
-  assert.match(stage, /--text-h2/);
+  assert.match(stage, /--text-section-title-mobile/);
   assert.match(stage, /--touch-target-min/);
 
   assert.match(explorer, /sortedTracks = \[\.\.\.tracks\]\.sort/);
@@ -293,3 +293,68 @@ test('MEASURE is published-first and preserves all evidence provenance on mobile
   assert.match(explorer, /NO PUBLIC SNAPSHOT YET/);
   assert.match(explorer, /No fallback or invented performance values are shown/);
 });
+
+
+test('homepage uses canonical type roles across every narrative stage', () => {
+  const tokens = read('src/styles/tokens.css');
+  const layout = read('src/layouts/BaseLayout.astro');
+  const reset = read('src/styles/reset.css');
+  const plane = read('src/components/landing/PlaneTemplate.astro');
+  const evidence = read('src/components/landing/EvidenceStage.astro');
+  const about = read('src/components/landing/AboutSignal.astro');
+
+  assert.match(layout, /family=Inter:wght@400;500;600;700;800/);
+  assert.match(layout, /Plus\+Jakarta\+Sans:ital,wght@0,500;0,600;0,700;0,800/);
+  assert.match(reset, /font-family:\s*var\(--font-body\)/);
+
+  for (const token of [
+    '--text-section-title:', '--text-section-title-mobile:',
+    '--text-section-intro:', '--text-section-intro-mobile:',
+    '--text-card-title:', '--text-feature-title:', '--text-kpi:',
+    '--weight-body:', '--weight-medium:', '--weight-label:',
+    '--weight-heading:', '--weight-display:',
+    '--leading-section-title:', '--tracking-section-title:',
+  ]) {
+    assert.ok(tokens.includes(token), 'Missing canonical typography role ' + token);
+  }
+
+  for (const [name, source] of [['DECIDE/BUILD/TEST', plane], ['MEASURE', evidence], ['ABOUT', about]]) {
+    assert.match(source, /font-size:\s*var\(--text-section-title\)/, name + ' should share desktop title scale');
+    assert.match(source, /font-size:\s*var\(--text-section-title-mobile\)/, name + ' should share phone title scale');
+    assert.match(source, /font-weight:\s*var\(--weight-display\)/, name + ' should use real loaded display weight');
+    assert.match(source, /letter-spacing:\s*var\(--tracking-section-title\)/, name + ' should share heading tracking');
+    assert.match(source, /font-size:\s*var\(--text-section-intro-mobile\)/, name + ' should share phone intro scale');
+  }
+
+  for (const path of [
+    'src/components/landing/LandingHero.astro',
+    'src/components/landing/DecisionTable.astro',
+    'src/components/landing/BuildSystemsShowcase.astro',
+    'src/components/landing/TestProductGallery.astro',
+    'src/components/landing/ExperimentResultsExplorer.astro',
+    'src/components/landing/EvidenceStage.astro',
+    'src/components/landing/AboutSignal.astro',
+    'src/components/landing/StageRail.astro',
+    'src/components/landing/MethodThread.astro',
+    'src/components/landing/PlaneTemplate.astro',
+    'src/components/layout/SiteHeader.astro',
+    'src/components/layout/SiteFooter.astro',
+  ]) {
+    const source = read(path);
+    assert.doesNotMatch(source, /font-weight:\s*(?:4[1-9]\d|5\d\d|6\d\d|7\d\d|8\d\d)\s*;/,
+      path + ' must not introduce ad-hoc unsourced weights');
+    assert.doesNotMatch(source, /font-family:\s*['"](?:Arial|Helvetica|Roboto|Georgia)/,
+      path + ' must not introduce a third non-brand font');
+  }
+
+  for (const path of [
+    'src/components/landing/DecisionTable.astro',
+    'src/components/landing/BuildSystemsShowcase.astro',
+    'src/components/landing/TestProductGallery.astro',
+    'src/components/landing/ExperimentResultsExplorer.astro',
+  ]) {
+    const source = read(path);
+    assert.match(source, /var\(--text-card-title\)|var\(--text-feature-title\)/,
+      path + ' must share canonical card typography');
+  }
+});