diff --git a/layout-review/04_missing_handler.html b/layout-review/04_missing_handler.html
index 8475a01..53aca8e 100644
--- a/layout-review/04_missing_handler.html
+++ b/layout-review/04_missing_handler.html
@@ -63,39 +63,44 @@
 
       <hr class="dt-divider">
 
-      <!-- Options expander (Missingness profile + Strategy) -->
-      <details class="dt-expander">
+      <!-- Missingness profile — always visible: see the damage before configuring -->
+      <h2>Missingness profile</h2>
+      <div class="dt-metrics">
+        <div class="dt-metric"><div class="label">Rows</div><div class="value">2,150</div></div>
+        <div class="dt-metric"><div class="label">Cells missing</div><div class="value">1,043</div></div>
+        <div class="dt-metric"><div class="label">% cells missing</div><div class="value">8.1%</div></div>
+        <div class="dt-metric"><div class="label">Complete rows</div><div class="value">1,388</div></div>
+      </div>
+      <div class="dt-table-wrap">
+        <table class="dt-table">
+          <thead><tr><th>column</th><th>dtype</th><th>missing</th><th>missing_pct</th><th>disguised</th><th>has_missing</th></tr></thead>
+          <tbody>
+            <tr><td>respondent_id</td><td>object</td><td>0</td><td>0.0%</td><td>0</td><td>False</td></tr>
+            <tr><td>age</td><td>float64</td><td>187</td><td>8.7%</td><td>61</td><td>True</td></tr>
+            <tr><td>region</td><td>object</td><td>142</td><td>6.6%</td><td>142</td><td>True</td></tr>
+            <tr><td>income</td><td>float64</td><td>329</td><td>15.3%</td><td>118</td><td>True</td></tr>
+            <tr><td>satisfaction</td><td>float64</td><td>95</td><td>4.4%</td><td>40</td><td>True</td></tr>
+            <tr><td>comments</td><td>object</td><td>290</td><td>13.5%</td><td>290</td><td>True</td></tr>
+          </tbody>
+        </table>
+      </div>
+
+      <hr class="dt-divider">
+
+      <!-- Options expander (Strategy) — configuration follows the diagnostic -->
+      <details class="dt-expander" open>
         <summary>Options</summary>
         <div class="dt-expander-body">
 
-          <h3>Missingness profile</h3>
-          <div class="dt-metrics">
-            <div class="dt-metric"><div class="label">Rows</div><div class="value">2,150</div></div>
-            <div class="dt-metric"><div class="label">Cells missing</div><div class="value">1,043</div></div>
-            <div class="dt-metric"><div class="label">% cells missing</div><div class="value">8.1%</div></div>
-            <div class="dt-metric"><div class="label">Complete rows</div><div class="value">1,388</div></div>
-          </div>
-
-          <div class="dt-table-wrap">
-            <table class="dt-table">
-              <thead><tr><th>column</th><th>dtype</th><th>missing</th><th>missing_pct</th><th>disguised</th><th>has_missing</th></tr></thead>
-              <tbody>
-                <tr><td>respondent_id</td><td>object</td><td>0</td><td>0.0%</td><td>0</td><td>False</td></tr>
-                <tr><td>age</td><td>float64</td><td>187</td><td>8.7%</td><td>61</td><td>True</td></tr>
-                <tr><td>region</td><td>object</td><td>142</td><td>6.6%</td><td>142</td><td>True</td></tr>
-                <tr><td>income</td><td>float64</td><td>329</td><td>15.3%</td><td>118</td><td>True</td></tr>
-                <tr><td>satisfaction</td><td>float64</td><td>95</td><td>4.4%</td><td>40</td><td>True</td></tr>
-                <tr><td>comments</td><td>object</td><td>290</td><td>13.5%</td><td>290</td><td>True</td></tr>
-              </tbody>
-            </table>
-          </div>
-
-          <hr class="dt-divider">
-
           <h3>Strategy</h3>
+          <div class="dt-precedence">
+            <span class="dt-mi">layers</span>
+            <span>Resolution order: <strong>per-column override</strong> → <strong>global strategy</strong> → <strong>preset</strong>. The most specific setting wins; layers it overrides are dimmed.</span>
+          </div>
           <div class="dt-field">
             <label class="dt-label">Preset</label>
-            <div class="dt-radio-row" style="flex-direction:column;gap:10px">
+            <div class="dt-help-text" style="color:var(--warn);display:flex;align-items:center;gap:5px;margin-bottom:8px"><span class="dt-mi" style="font-family:'Material Symbols Outlined';font-size:15px;line-height:1">info</span> Overridden by <strong>Global strategy → median</strong> (set under Advanced options). Presets apply only when global is &ldquo;(use preset)&rdquo;.</div>
+            <div class="dt-radio-row is-overridden" style="flex-direction:column;gap:10px">
               <span class="dt-radio on"><span class="dot"></span> detect-only (standardize sentinels to NaN, no fill or drop)</span>
               <span class="dt-radio"><span class="dot"></span> safe-fill (numeric → median, categorical → mode)</span>
               <span class="dt-radio"><span class="dot"></span> drop-incomplete (drop any row with missing)</span>
@@ -121,7 +126,7 @@
                   <h4>Strategy override</h4>
                   <div class="dt-field">
                     <label class="dt-label">Global strategy</label>
-                    <div class="dt-select">(use preset)</div>
+                    <div class="dt-select">median</div>
                     <div class="dt-help-text">drop_row / drop_col use the thresholds below. mean / median / interpolate are numeric only — non-numeric columns fall back to the categorical strategy.</div>
                   </div>
                   <div class="dt-field">
@@ -135,11 +140,11 @@
               <div class="dt-cols-2">
                 <div class="dt-field">
                   <label class="dt-label">Row drop threshold (drop rows with ≥ this fraction missing across selected cols)</label>
-                  <div class="dt-slider"><div class="track"><div class="fill" style="width:100%"></div><div class="knob" style="left:100%"></div></div><div class="val">1.00</div></div>
+                  <div class="dt-slider"><div class="track"><div class="fill" style="width:100%"></div><div class="knob" style="left:calc(100% - 8px)"></div></div><div class="val">1.00</div></div>
                 </div>
                 <div class="dt-field">
                   <label class="dt-label">Column drop threshold (drop columns with ≥ this fraction missing)</label>
-                  <div class="dt-slider"><div class="track"><div class="fill" style="width:100%"></div><div class="knob" style="left:100%"></div></div><div class="val">1.00</div></div>
+                  <div class="dt-slider"><div class="track"><div class="fill" style="width:100%"></div><div class="knob" style="left:calc(100% - 8px)"></div></div><div class="val">1.00</div></div>
                 </div>
               </div>
 
@@ -164,13 +169,13 @@
               <p class="dt-caption">Set a different strategy for specific columns. Leave any row blank to use the global strategy.</p>
               <div class="dt-table-wrap">
                 <table class="dt-table">
-                  <thead><tr><th>Column</th><th>Override</th></tr></thead>
+                  <thead><tr><th>Column</th><th>Override</th><th>Resolves to</th></tr></thead>
                   <tbody>
-                    <tr><td>age</td><td><span class="dt-select" style="display:inline-block;min-width:160px;padding:4px 24px 4px 10px">median</span></td></tr>
-                    <tr><td>region</td><td><span class="dt-select" style="display:inline-block;min-width:160px;padding:4px 24px 4px 10px">mode</span></td></tr>
-                    <tr><td>income</td><td><span class="dt-select" style="display:inline-block;min-width:160px;padding:4px 24px 4px 10px"></span></td></tr>
-                    <tr><td>satisfaction</td><td><span class="dt-select" style="display:inline-block;min-width:160px;padding:4px 24px 4px 10px"></span></td></tr>
-                    <tr><td>comments</td><td><span class="dt-select" style="display:inline-block;min-width:160px;padding:4px 24px 4px 10px">constant</span></td></tr>
+                    <tr><td>age</td><td><span class="dt-select" style="display:inline-block;min-width:160px;padding:4px 24px 4px 10px;color:var(--ink-tertiary)">(global)</span></td><td>median <span style="color:var(--ink-tertiary);font-size:11px">· global</span></td></tr>
+                    <tr><td>region</td><td><span class="dt-select" style="display:inline-block;min-width:160px;padding:4px 24px 4px 10px;color:var(--ink-tertiary)">(global)</span></td><td>mode <span style="color:var(--ink-tertiary);font-size:11px">· global → categorical fallback</span></td></tr>
+                    <tr><td>income</td><td><span class="dt-select" style="display:inline-block;min-width:160px;padding:4px 24px 4px 10px;color:var(--ink-tertiary)">(global)</span></td><td>median <span style="color:var(--ink-tertiary);font-size:11px">· global</span></td></tr>
+                    <tr><td>satisfaction</td><td><span class="dt-select" style="display:inline-block;min-width:160px;padding:4px 24px 4px 10px;color:var(--ink-tertiary)">(global)</span></td><td>median <span style="color:var(--ink-tertiary);font-size:11px">· global</span></td></tr>
+                    <tr><td>comments</td><td><span class="dt-select" style="display:inline-block;min-width:160px;padding:4px 24px 4px 10px">constant</span></td><td><strong>constant</strong> <span style="color:var(--ink-tertiary);font-size:11px">· this column</span></td></tr>
                   </tbody>
                 </table>
               </div>
@@ -198,28 +203,14 @@
       <p><strong>Missingness — before vs. after</strong></p>
       <div class="dt-table-wrap">
         <table class="dt-table">
-          <thead><tr><th>column</th><th>before_missing</th><th>before_pct</th><th>after_missing</th><th>after_pct</th></tr></thead>
+          <thead><tr><th>column</th><th>before_missing</th><th>before_pct</th><th>after_missing</th><th>after_pct</th><th>strategy</th></tr></thead>
           <tbody>
-            <tr><td>respondent_id</td><td>0</td><td>0.0</td><td class="dt-cell-add">0</td><td class="dt-cell-add">0.0</td></tr>
-            <tr><td>age</td><td class="dt-cell-flag">187</td><td>8.7</td><td class="dt-cell-add">0</td><td class="dt-cell-add">0.0</td></tr>
-            <tr><td>region</td><td class="dt-cell-flag">142</td><td>6.6</td><td class="dt-cell-add">0</td><td class="dt-cell-add">0.0</td></tr>
-            <tr><td>income</td><td class="dt-cell-flag">329</td><td>15.3</td><td class="dt-cell-add">0</td><td class="dt-cell-add">0.0</td></tr>
-            <tr><td>satisfaction</td><td class="dt-cell-flag">95</td><td>4.4</td><td class="dt-cell-add">0</td><td class="dt-cell-add">0.0</td></tr>
-            <tr><td>comments</td><td class="dt-cell-flag">290</td><td>13.5</td><td class="dt-cell-add">0</td><td class="dt-cell-add">0.0</td></tr>
-          </tbody>
-        </table>
-      </div>
-
-      <p><strong>Strategy applied per column</strong></p>
-      <div class="dt-table-wrap">
-        <table class="dt-table">
-          <thead><tr><th>column</th><th>strategy</th></tr></thead>
-          <tbody>
-            <tr><td>age</td><td>median</td></tr>
-            <tr><td>region</td><td>mode</td></tr>
-            <tr><td>income</td><td>median</td></tr>
-            <tr><td>satisfaction</td><td>median</td></tr>
-            <tr><td>comments</td><td>constant</td></tr>
+            <tr><td>respondent_id</td><td>0</td><td>0.0</td><td>0</td><td>0.0</td><td class="dt-cell-flag">—</td></tr>
+            <tr><td>age</td><td class="dt-cell-flag">187</td><td>8.7</td><td class="dt-cell-add">0</td><td class="dt-cell-add">0.0</td><td>median</td></tr>
+            <tr><td>region</td><td class="dt-cell-flag">142</td><td>6.6</td><td class="dt-cell-add">0</td><td class="dt-cell-add">0.0</td><td>mode</td></tr>
+            <tr><td>income</td><td class="dt-cell-flag">329</td><td>15.3</td><td class="dt-cell-add">0</td><td class="dt-cell-add">0.0</td><td>median</td></tr>
+            <tr><td>satisfaction</td><td class="dt-cell-flag">95</td><td>4.4</td><td class="dt-cell-add">0</td><td class="dt-cell-add">0.0</td><td>median</td></tr>
+            <tr><td>comments</td><td class="dt-cell-flag">290</td><td>13.5</td><td class="dt-cell-add">0</td><td class="dt-cell-add">0.0</td><td>constant</td></tr>
           </tbody>
         </table>
       </div>
diff --git a/layout-review/app.css b/layout-review/app.css
index 11b3a04..9ce8263 100644
--- a/layout-review/app.css
+++ b/layout-review/app.css
@@ -330,6 +330,20 @@ code, .dt-mono { font-family: var(--font-mono); font-size: 0.92em; font-feature-
 .dt-radio .dot { width: 16px; height: 16px; border-radius: 50%; border: 1px solid var(--border-strong); display: inline-block; flex-shrink: 0; }
 .dt-radio.on .dot { border: 5px solid var(--ink); }
 
+/* Strategy precedence legend + overridden state (Fix Missing Values).
+   Makes the preset -> global -> per-column resolution order legible and
+   visibly dims a layer when a more specific layer wins. */
+.dt-precedence {
+  display: flex; align-items: center; gap: 8px;
+  background: var(--surface-hover); border: 1px solid var(--border);
+  border-radius: var(--r-md); padding: 9px 13px; margin: 0 0 14px;
+  font-size: 12.5px; color: var(--ink-secondary); line-height: 1.4;
+}
+.dt-precedence .dt-mi { font-family: "Material Symbols Outlined"; font-size: 18px; color: var(--ink-tertiary); flex-shrink: 0; }
+.dt-precedence strong { color: var(--ink); font-weight: 600; }
+.dt-radio-row.is-overridden { opacity: 0.5; }
+.dt-radio-row.is-overridden .dt-radio { text-decoration: line-through; text-decoration-color: var(--ink-tertiary); }
+
 /* Slider */
 .dt-slider { margin: 14px 0 6px; }
 .dt-slider .track { position: relative; height: 4px; background: var(--border-strong); border-radius: 2px; }