diff --git a/CHANGELOG.md b/CHANGELOG.md
index b985833..5a51010 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,10 +2,14 @@
 
 ## Versión actual
 
-- Versión base: `1.2.12`
+- Versión base: `1.2.13`
 
 ## Historial
 
+### 1.2.13 - 2026-04-27
+
+- Web y Android ocultan por defecto los detalles avanzados de `Firmar ahora` y los muestran solo bajo demanda con botón de ojo.
+
 ### 1.2.12 - 2026-04-23
 
 - Web reordena el menú principal para mostrar `Firmar ahora` en segunda posición y `Mis documentos` justo debajo.
diff --git a/VERSION b/VERSION
index f2ae0b4..0b1f1ed 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-1.2.12
+1.2.13
diff --git a/android/app/build.gradle b/android/app/build.gradle
index 817682f..038ddf8 100644
--- a/android/app/build.gradle
+++ b/android/app/build.gradle
@@ -18,8 +18,8 @@ android {
         applicationId "net.linkedcorp.linkedsign"
         minSdk 26
         targetSdk 35
-        versionCode 10212
-        versionName "1.2.12"
+        versionCode 10213
+        versionName "1.2.13"
 
         buildConfigField "String", "API_BASE_URL", "\"${apiBaseUrl}\""
     }
diff --git a/android/app/src/main/java/net/linkedcorp/linkedsign/ui/LinkedSignApp.kt b/android/app/src/main/java/net/linkedcorp/linkedsign/ui/LinkedSignApp.kt
index 71add51..16734b4 100644
--- a/android/app/src/main/java/net/linkedcorp/linkedsign/ui/LinkedSignApp.kt
+++ b/android/app/src/main/java/net/linkedcorp/linkedsign/ui/LinkedSignApp.kt
@@ -1330,6 +1330,7 @@ private fun SignScreen(
     var certPassword by rememberSaveable { mutableStateOf("") }
     var reason by rememberSaveable { mutableStateOf("Firmado digitalmente") }
     var location by rememberSaveable { mutableStateOf("") }
+    var showAdvancedOptions by remember { mutableStateOf(false) }
     var currentPageIndex by rememberSaveable(selectedDocumentId) { mutableStateOf(0) }
     var preview by remember(selectedDocumentId) { mutableStateOf<PdfPreviewState?>(null) }
     var placement by remember(selectedDocumentId) { mutableStateOf<SignaturePlacement?>(null) }
@@ -1339,6 +1340,9 @@ private fun SignScreen(
     val selectedDocument = state.documents.firstOrNull { it.id.toString() == selectedDocumentId }
     val signerLabel = state.userName ?: state.userEmail ?: "Firmante"
     val signatureStyle = state.signaturePreferences?.signatureStyle ?: "qr"
+    val qrPosition = state.signaturePreferences?.qrPosition ?: "left"
+    val qrBackground = state.signaturePreferences?.qrBackground ?: "transparent"
+    val qrBorder = state.signaturePreferences?.qrBorder ?: "none"
 
     LaunchedEffect(initialDocumentId, state.documents) {
         val documentId = initialDocumentId ?: return@LaunchedEffect
@@ -1360,7 +1364,6 @@ private fun SignScreen(
     ) {
         item {
             SectionCard(title = "Vista previa y firma") {
-                Text("Esta versión usa la configuración visual de firma ya guardada en tu cuenta.", color = TextMuted, fontSize = AppFontSizes.sm)
                 DropdownSelector(
                     label = "Documento",
                     options = state.documents.associate { it.id.toString() to (it.title ?: it.filename ?: "Documento ${it.id}") },
@@ -1374,8 +1377,37 @@ private fun SignScreen(
                     onSelect = { selectedCertificateId = it }
                 )
                 AppTextField(value = certPassword, onValueChange = { certPassword = it }, label = "Contraseña del certificado", isPassword = true)
-                AppTextField(value = reason, onValueChange = { reason = it }, label = "Razón")
-                AppTextField(value = location, onValueChange = { location = it }, label = "Ubicación")
+                OutlinedActionButton(
+                    label = if (showAdvancedOptions) "Ocultar detalles" else "Mostrar detalles",
+                    icon = if (showAdvancedOptions) Icons.Outlined.VisibilityOff else Icons.Outlined.Visibility
+                ) {
+                    showAdvancedOptions = !showAdvancedOptions
+                }
+                if (showAdvancedOptions) {
+                    Text("Esta versión usa la configuración visual de firma ya guardada en tu cuenta.", color = TextMuted, fontSize = AppFontSizes.sm)
+                    AppTextField(value = reason, onValueChange = { reason = it }, label = "Razón")
+                    AppTextField(value = location, onValueChange = { location = it }, label = "Ubicación")
+                    Surface(
+                        modifier = Modifier.fillMaxWidth(),
+                        shape = RoundedCornerShape(18.dp),
+                        color = SurfaceSoft,
+                        border = BorderStroke(1.dp, StrokeSoft)
+                    ) {
+                        Column(
+                            modifier = Modifier.padding(16.dp),
+                            verticalArrangement = Arrangement.spacedBy(6.dp)
+                        ) {
+                            Text("Estilo aplicado", color = BrandDark, fontSize = AppFontSizes.base, fontWeight = FontWeight.SemiBold)
+                            Text("La firma usará tu configuración guardada en el menú Estilo Firma.", color = TextMuted, fontSize = AppFontSizes.sm)
+                            Text("Tipo: $signatureStyle", color = BrandDark, fontSize = AppFontSizes.sm)
+                            if (signatureStyle == "qr") {
+                                Text("Posición QR: ${if (qrPosition == "left") "Izquierda" else "Derecha"}", color = BrandDark, fontSize = AppFontSizes.sm)
+                                Text("Fondo: ${if (qrBackground == "transparent") "Transparente" else "Suave"}", color = BrandDark, fontSize = AppFontSizes.sm)
+                                Text("Borde: ${if (qrBorder == "none") "Sin borde" else "Con borde"}", color = BrandDark, fontSize = AppFontSizes.sm)
+                            }
+                        }
+                    }
+                }
                 OutlinedActionButton("Cargar PDF para ubicar firma", Icons.Outlined.Description) {
                     val documentId = selectedDocumentId.toIntOrNull() ?: return@OutlinedActionButton
                     scope.launch {
diff --git a/backend/package.json b/backend/package.json
index bb73407..743660f 100644
--- a/backend/package.json
+++ b/backend/package.json
@@ -1,6 +1,6 @@
 {
   "name": "linkedsign-backend",
-  "version": "1.2.12",
+  "version": "1.2.13",
   "private": true,
   "description": "Initial backend for LinkedSign",
   "main": "src/server.js",
diff --git a/frontend/package.json b/frontend/package.json
index a0d7914..7fcbdc6 100644
--- a/frontend/package.json
+++ b/frontend/package.json
@@ -1,7 +1,7 @@
 {
   "name": "frontend",
   "private": true,
-  "version": "1.2.12",
+  "version": "1.2.13",
   "type": "module",
   "scripts": {
     "dev": "vite",
diff --git a/frontend/src/index.css b/frontend/src/index.css
index 74905c0..d876b22 100644
--- a/frontend/src/index.css
+++ b/frontend/src/index.css
@@ -1059,6 +1059,13 @@ select {
   justify-content: center;
 }
 
+.btn-inline-toggle {
+  width: fit-content;
+  display: inline-flex;
+  align-items: center;
+  gap: 8px;
+}
+
 .sign-form-card form { display: flex; flex-direction: column; gap: 14px; }
 
 .sign-info-panel { display: flex; flex-direction: column; gap: 14px; }
@@ -2314,6 +2321,11 @@ select {
     flex: 1;
   }
 
+  .btn-inline-toggle {
+    width: 100%;
+    justify-content: center;
+  }
+
   .steps-bar {
     flex-direction: column;
     align-items: stretch;
diff --git a/frontend/src/pages/signatures/SignaturesPage.jsx b/frontend/src/pages/signatures/SignaturesPage.jsx
index d7e40a2..0b4a5f2 100644
--- a/frontend/src/pages/signatures/SignaturesPage.jsx
+++ b/frontend/src/pages/signatures/SignaturesPage.jsx
@@ -3,7 +3,7 @@ import { useSearchParams } from 'react-router-dom';
 import { listDocuments, downloadDocument, uploadDocument } from '../../api/documents';
 import { listCertificates } from '../../api/certificates';
 import { signDocument, getSignatures, downloadSigned } from '../../api/signatures';
-import { PenTool, FileText, Shield, CheckCircle, MapPin, Download, Check, Plus } from 'lucide-react';
+import { PenTool, FileText, Shield, CheckCircle, MapPin, Download, Check, Plus, Eye, EyeOff } from 'lucide-react';
 import toast from 'react-hot-toast';
 import PasswordModal from '../../components/ui/PasswordModal';
 import PdfSignaturePlacer from '../../components/ui/PdfSignaturePlacer';
@@ -40,6 +40,7 @@ export default function SignaturesPage() {
   const [pendingSign, setPendingSign] = useState(null);
   const [uploadingDocument, setUploadingDocument] = useState(false);
   const [pendingLocalDocument, setPendingLocalDocument] = useState(null);
+  const [showAdvancedOptions, setShowAdvancedOptions] = useState(false);
   const documentInputRef = useRef(null);
 
   useEffect(() => {
@@ -293,22 +294,34 @@ export default function SignaturesPage() {
               </select>
               {certs.length === 0 && <small className="field-hint">No tienes certificados activos.</small>}
             </div>
-            <div className="field">
-              <label>Razón de firma</label>
-              <input type="text" name="reason" value={form.reason} onChange={handleChange} />
-            </div>
-            <div className="field">
-              <label>Ubicación</label>
-              <input type="text" name="location" value={form.location} onChange={handleChange} placeholder="Ciudad, País..." />
-            </div>
-            <div className="info-box">
-              <h4>Estilo aplicado</h4>
-              <p>La firma usará tu configuración guardada en el menú <strong>Estilo Firma</strong>.</p>
-              <p><strong>Tipo:</strong> {form.signatureStyle}</p>
-              {form.signatureStyle === 'qr' && <p><strong>Posición QR:</strong> {form.qrPosition === 'left' ? 'Izquierda' : 'Derecha'}</p>}
-              {form.signatureStyle === 'qr' && <p><strong>Fondo:</strong> {form.qrBackground === 'transparent' ? 'Transparente' : 'Suave'}</p>}
-              {form.signatureStyle === 'qr' && <p><strong>Borde:</strong> {form.qrBorder === 'none' ? 'Sin borde' : 'Con borde'}</p>}
-            </div>
+            <button
+              type="button"
+              className="btn btn-ghost btn-inline-toggle"
+              onClick={() => setShowAdvancedOptions((current) => !current)}
+            >
+              {showAdvancedOptions ? <EyeOff size={16} /> : <Eye size={16} />}
+              {showAdvancedOptions ? 'Ocultar detalles' : 'Mostrar detalles'}
+            </button>
+            {showAdvancedOptions && (
+              <>
+                <div className="field">
+                  <label>Razón de firma</label>
+                  <input type="text" name="reason" value={form.reason} onChange={handleChange} />
+                </div>
+                <div className="field">
+                  <label>Ubicación</label>
+                  <input type="text" name="location" value={form.location} onChange={handleChange} placeholder="Ciudad, País..." />
+                </div>
+                <div className="info-box">
+                  <h4>Estilo aplicado</h4>
+                  <p>La firma usará tu configuración guardada en el menú <strong>Estilo Firma</strong>.</p>
+                  <p><strong>Tipo:</strong> {form.signatureStyle}</p>
+                  {form.signatureStyle === 'qr' && <p><strong>Posición QR:</strong> {form.qrPosition === 'left' ? 'Izquierda' : 'Derecha'}</p>}
+                  {form.signatureStyle === 'qr' && <p><strong>Fondo:</strong> {form.qrBackground === 'transparent' ? 'Transparente' : 'Suave'}</p>}
+                  {form.signatureStyle === 'qr' && <p><strong>Borde:</strong> {form.qrBorder === 'none' ? 'Sin borde' : 'Con borde'}</p>}
+                </div>
+              </>
+            )}
             <button className="btn btn-primary btn-full" onClick={handleGoToPlace}>
               <MapPin size={16} /> Elegir posición de firma →
             </button>
@@ -372,7 +385,7 @@ export default function SignaturesPage() {
           <div className="step-nav">
             <button className="btn btn-ghost" onClick={() => setStep(0)}>← Volver</button>
             <p className="step-desc">
-              Haz clic donde quieres que aparezca la firma en <strong>{selectedDoc?.title}</strong>
+              Haz clic donde quieres que aparezca la firma en <strong>{selectedDocumentTitle}</strong>
             </p>
           </div>
           <PdfSignaturePlacer
@@ -396,15 +409,27 @@ export default function SignaturesPage() {
             <h3>Posición confirmada — listo para firmar</h3>
           </div>
           <div className="sign-confirm-details">
-            <p><strong>Documento:</strong> {selectedDoc?.title}</p>
+            <p><strong>Documento:</strong> {selectedDocumentTitle}</p>
             <p><strong>Certificado:</strong> {selectedCert?.alias}</p>
-            <p><strong>Razón:</strong> {form.reason}</p>
-            {form.location && <p><strong>Ubicación:</strong> {form.location}</p>}
-            <p><strong>Estilo visual:</strong> {form.signatureStyle}</p>
-            {form.signatureStyle === 'qr' && <p><strong>Posición QR:</strong> {form.qrPosition === 'left' ? 'Izquierda' : 'Derecha'}</p>}
-            {form.signatureStyle === 'qr' && <p><strong>Fondo:</strong> {form.qrBackground === 'transparent' ? 'Transparente' : 'Suave'}</p>}
-            {form.signatureStyle === 'qr' && <p><strong>Borde:</strong> {form.qrBorder === 'none' ? 'Sin borde' : 'Con borde'}</p>}
             <p><strong>Página:</strong> {(sigPlacement?.page ?? 0) + 1}</p>
+            <button
+              type="button"
+              className="btn btn-ghost btn-inline-toggle"
+              onClick={() => setShowAdvancedOptions((current) => !current)}
+            >
+              {showAdvancedOptions ? <EyeOff size={16} /> : <Eye size={16} />}
+              {showAdvancedOptions ? 'Ocultar detalles' : 'Mostrar detalles'}
+            </button>
+            {showAdvancedOptions && (
+              <>
+                <p><strong>Razón:</strong> {form.reason}</p>
+                {form.location && <p><strong>Ubicación:</strong> {form.location}</p>}
+                <p><strong>Estilo visual:</strong> {form.signatureStyle}</p>
+                {form.signatureStyle === 'qr' && <p><strong>Posición QR:</strong> {form.qrPosition === 'left' ? 'Izquierda' : 'Derecha'}</p>}
+                {form.signatureStyle === 'qr' && <p><strong>Fondo:</strong> {form.qrBackground === 'transparent' ? 'Transparente' : 'Suave'}</p>}
+                {form.signatureStyle === 'qr' && <p><strong>Borde:</strong> {form.qrBorder === 'none' ? 'Sin borde' : 'Con borde'}</p>}
+              </>
+            )}
           </div>
           <div className="sign-confirm-actions">
             <button className="btn btn-ghost" onClick={() => setStep(1)}>← Cambiar posición</button>