diff --git a/static/js/cookbookServe.js b/static/js/cookbookServe.js
index 5a5d6dfc1..099da1779 100644
--- a/static/js/cookbookServe.js
+++ b/static/js/cookbookServe.js
@@ -1258,7 +1258,7 @@ function _rerenderCachedModels() {
       // stays as the source-of-truth so every existing change handler
       // (updateBackendVisibility, runtime readiness, command builder)
       // still fires via dispatchEvent('change') on selection.
-      panelHtml += `<label>${_l('Engine','Inference engine: vLLM, SGLang, llama.cpp, Ollama, or Diffusers')}<div class="hwfit-backend-picker" data-backend-picker style="position:relative;width:100%;"><select class="hwfit-sf hwfit-backend-source" data-field="backend" style="display:none;">${backendOpts}</select><button type="button" class="hwfit-backend-btn" data-backend-btn aria-haspopup="listbox" aria-expanded="false" style="display:flex;align-items:center;gap:6px;width:100%;height:28px;padding:0 8px;background:var(--bg);color:var(--fg);border:1px solid var(--border);border-radius:4px;font:inherit;font-size:11px;cursor:pointer;text-align:left;position:relative;top:-3px;"><span class="hwfit-backend-btn-icon" data-backend-icon-slot aria-hidden="true" style="display:inline-flex;align-items:center;justify-content:center;width:16px;height:16px;color:var(--accent, var(--red));flex-shrink:0;"></span><span class="hwfit-backend-btn-label" data-backend-label style="flex:1;min-width:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;"></span><svg width="10" height="10" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2.5" stroke-linecap="round" stroke-linejoin="round" aria-hidden="true" style="opacity:0.6;flex-shrink:0;"><polyline points="6 9 12 15 18 9"/></svg></button><div class="hwfit-backend-menu" data-backend-menu role="listbox" hidden style="position:absolute;top:calc(100% + 4px);left:0;right:0;z-index:100;background:var(--panel, var(--bg));border:1px solid var(--border);border-radius:6px;box-shadow:0 6px 20px rgba(0,0,0,0.22);padding:4px;"></div></div></label>`;
+      panelHtml += `<label>${_l('Engine','Inference engine: vLLM, SGLang, llama.cpp, Ollama, or Diffusers')}<div class="hwfit-backend-picker" data-backend-picker style="position:relative;width:100%;"><select class="hwfit-sf hwfit-backend-source" data-field="backend" style="display:none;">${backendOpts}</select><button type="button" class="hwfit-backend-btn" data-backend-btn aria-haspopup="listbox" aria-expanded="false" style="display:flex;align-items:center;gap:6px;width:100%;height:32px;padding:0 8px;background:var(--bg);color:var(--fg);border:1px solid var(--border);border-radius:4px;font:inherit;font-size:11px;cursor:pointer;text-align:left;position:relative;top:-3px;"><span class="hwfit-backend-btn-icon" data-backend-icon-slot aria-hidden="true" style="display:inline-flex;align-items:center;justify-content:center;width:16px;height:16px;color:var(--accent, var(--red));flex-shrink:0;"></span><span class="hwfit-backend-btn-label" data-backend-label style="flex:1;min-width:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;"></span><svg width="10" height="10" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2.5" stroke-linecap="round" stroke-linejoin="round" aria-hidden="true" style="opacity:0.6;flex-shrink:0;"><polyline points="6 9 12 15 18 9"/></svg></button><div class="hwfit-backend-menu" data-backend-menu role="listbox" hidden style="position:absolute;top:calc(100% + 4px);left:0;right:0;z-index:100;background:var(--panel, var(--bg));border:1px solid var(--border);border-radius:6px;box-shadow:0 6px 20px rgba(0,0,0,0.22);padding:4px;"></div></div></label>`;
       panelHtml += `<input type="hidden" class="hwfit-sf" data-field="host" value="${esc(_es.remoteHost || '')}" />`;
       // Inference mode pill (llama.cpp only) — lives directly to the
       // RIGHT of Backend in Row 1 so the engine and the GPU/CPU choice
@@ -1383,10 +1383,9 @@ function _rerenderCachedModels() {
       // tuning, or any other KEY=VALUE pair that doesn't have a dedicated
       // field. After the venv activate runs, $VIRTUAL_ENV / $PATH / etc. are
       // already exported so they expand correctly here.
-      // grid-column: 1 / -1 makes Env span every column of the Advanced
-      // row's CSS grid (the old flex:1 1 100% did nothing in a grid
-      // container — left an empty trailing column gap on wide modals).
-      panelHtml += `<label class="hwfit-backend-vllm hwfit-backend-sglang" style="grid-column:2 / -1;">${_l('Env','Extra KEY=VALUE env-var pairs prepended to the launch (space-separated). The Env Preset above covers the usual MiniMax M3 values; use this for additional overrides.')}<input type="text" class="hwfit-sf" data-field="extra_env" value="${esc(svm('extra_env', sv('extra_env','')))}" placeholder="NCCL_P2P_DISABLE=1" style="width:100%;" /></label>`;
+      // CSS places this beside vLLM's Env Preset, but lets it span the full
+      // row for SGLang where that preset field is hidden.
+      panelHtml += `<label class="hwfit-backend-vllm hwfit-backend-sglang hwfit-extra-env-label">${_l('Env','Extra KEY=VALUE env-var pairs prepended to the launch (space-separated). The Env Preset above covers the usual MiniMax M3 values; use this for additional overrides.')}<input type="text" class="hwfit-sf" data-field="extra_env" value="${esc(svm('extra_env', sv('extra_env','')))}" placeholder="NCCL_P2P_DISABLE=1" style="width:100%;" /></label>`;
       panelHtml += `</div>`;
       // Row 2b: Diffusers settings
       const diffDtypeOpts = ['bfloat16','float16','float32'].map(d => `<option value="${d}"${sv('diff_dtype','bfloat16')===d?' selected':''}>${d}</option>`).join('');
@@ -1937,6 +1936,7 @@ function _rerenderCachedModels() {
 
       function updateBackendVisibility() {
         const b = panel.querySelector('[data-field="backend"]')?.value || 'vllm';
+        panel.dataset.backendActive = b;
         panel.querySelectorAll('[class*="hwfit-backend-"]').forEach(el => {
           // Skip the entire backend-picker subtree — the picker's own
           // classes (`hwfit-backend-picker`, `-btn`, `-menu`, `-item`,
diff --git a/static/style.css b/static/style.css
index 336fe5332..edfb49d89 100644
--- a/static/style.css
+++ b/static/style.css
@@ -20339,10 +20339,16 @@ body.gallery-selecting .gallery-dl-btn,
 .hwfit-sf[data-field="backend"],
 .hwfit-sf[data-field="dtype"],
 .hwfit-sf[data-field="tp"] {
-  height: 28px;
+  height: 32px;
   box-sizing: border-box;
   width: 100%;
 }
+.hwfit-extra-env-label {
+  grid-column: 1 / -1;
+}
+.hwfit-serve-panel[data-backend-active="vllm"] .hwfit-extra-env-label {
+  grid-column: 2 / -1;
+}
 .hwfit-sf:focus {
   border-color: var(--accent, var(--red));
   outline: none;