diff --git a/frontend/src/components/CardEditor.jsx b/frontend/src/components/CardEditor.jsx
index 4783869..4ca15f8 100644
--- a/frontend/src/components/CardEditor.jsx
+++ b/frontend/src/components/CardEditor.jsx
@@ -12,7 +12,7 @@ export default function CardEditor({ index, level, handleLevelChange, handleRemo
         <span className="absolute bottom-3 right-4 text-sm font-black text-slate-300 rotate-180">{index + 1}</span>
         <input type="text" placeholder="Término..." value={level} onChange={(e) => handleLevelChange(index, e.target.value)} className={`w-10/12 text-center text-lg font-bold text-slate-700 bg-transparent border-b-2 border-dashed outline-none pb-1 ${error ? 'border-red-300 focus:border-red-500 placeholder:text-red-200' : 'border-slate-300 focus:border-blue-500'}`} />
       </div>
-      <div className="h-6 mt-2">{error && <p className="text-red-500 text-xs font-semibold animate-pulse">Escribe un término</p>}</div>
+      <div className="h-6 mt-2">{error && <p className="text-red-500 text-xs font-semibold">Escribe un término</p>}</div>
     </div>
   );
 }
\ No newline at end of file
diff --git a/frontend/src/components/CriterionInput.jsx b/frontend/src/components/CriterionInput.jsx
index b636ede..55b1ce7 100644
--- a/frontend/src/components/CriterionInput.jsx
+++ b/frontend/src/components/CriterionInput.jsx
@@ -1,6 +1,6 @@
 export default function CriterionInput({ criterionName, setCriterionName, error }) {
   return (
-    <div className="flex flex-row items-center justify-center gap-3 w-full z-30 relative mb-2">
+    <div className="flex flex-row items-center justify-center gap-3 w-full z-30 relative mt-4">
       <label className="text-sm font-bold text-slate-600 uppercase tracking-wide whitespace-nowrap">
         Nombre del Criterio:
       </label>
@@ -19,8 +19,8 @@ export default function CriterionInput({ criterionName, setCriterionName, error
         />
         
         {error && (
-          <span className="absolute top-1/2 -right-24 -translate-y-1/2 text-xs font-bold text-red-500 animate-pulse whitespace-nowrap">
-            * Obligatorio
+          <span className="absolute top-1/2 -right-18 -translate-y-1/2 text-red-500 text-xs font-semibold">
+            Obligatorio
           </span>
         )}
       </div>
diff --git a/frontend/src/components/EyeIcon.jsx b/frontend/src/components/EyeIcon.jsx
deleted file mode 100644
index 70437ac..0000000
--- a/frontend/src/components/EyeIcon.jsx
+++ /dev/null
@@ -1,12 +0,0 @@
-export default function EyeIcon({ isOpen }) {
-  return isOpen ? (
-    <svg xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24" strokeWidth={2} stroke="currentColor" className="w-5 h-5">
-      <path strokeLinecap="round" strokeLinejoin="round" d="M2.036 12.322a1.012 1.012 0 010-.639C3.423 7.51 7.36 4.5 12 4.5c4.638 0 8.573 3.007 9.963 7.178.07.207.07.431 0 .639C20.577 16.49 16.64 19.5 12 19.5c-4.638 0-8.573-3.007-9.963-7.178z" />
-      <path strokeLinecap="round" strokeLinejoin="round" d="M15 12a3 3 0 11-6 0 3 3 0 016 0z" />
-    </svg>
-  ) : (
-    <svg xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24" strokeWidth={2} stroke="currentColor" className="w-5 h-5">
-      <path strokeLinecap="round" strokeLinejoin="round" d="M3.98 8.223A10.477 10.477 0 001.934 12C3.226 16.338 7.244 19.5 12 19.5c.993 0 1.953-.138 2.863-.395M6.228 6.228A10.45 10.45 0 0112 4.5c4.756 0 8.773 3.162 10.065 7.498a10.523 10.523 0 01-4.293 5.774M6.228 6.228L3 3m3.228 3.228l3.65 3.65m7.894 7.894L21 21m-3.228-3.228l-3.65-3.65m0 0a3 3 0 10-4.243-4.243m4.242 4.242L9.88 9.88" />
-    </svg>
-  );
-}
\ No newline at end of file
diff --git a/frontend/src/components/editor/Step1BaseScale.jsx b/frontend/src/components/editor/Step1BaseScale.jsx
index 7bdb24b..b3ba7d7 100644
--- a/frontend/src/components/editor/Step1BaseScale.jsx
+++ b/frontend/src/components/editor/Step1BaseScale.jsx
@@ -3,6 +3,7 @@ import CriterionInput from '../CriterionInput';
 import CardEditor from '../CardEditor';
 import BlankCardsCounter from '../BlankCardsCounter';
 import AddLevelButton from '../AddLevelButton';
+import { FiZoomIn, FiMaximize } from 'react-icons/fi';
 
 export default function Step1BaseScale({
   criterionName, handleCriterionChange,
@@ -51,15 +52,15 @@ export default function Step1BaseScale({
                 }} 
                 className={`flex items-center gap-2 px-3 py-1.5 rounded-lg font-bold transition-all shadow-sm border text-sm ${isZoomActive ? 'bg-blue-50 border-blue-200 text-blue-700' : 'bg-white border-slate-200 text-slate-600'}`}
             >
-                <span>{isZoomActive ? '🔍' : '🖼️'}</span>
-                {isZoomActive ? 'Ver de cerca (Scroll)' : 'Ajustar mesa'}
+                <span>{isZoomActive ? <FiZoomIn className="w-4 h-4" strokeWidth={2.5} /> : <FiMaximize className="w-4 h-4" strokeWidth={2.5}></FiMaximize> }</span>
+                {isZoomActive ? 'Ver de cerca' : 'Ajustar mesa'}
             </button>
             )}
         </div>
 
         <CriterionInput criterionName={criterionName} setCriterionName={handleCriterionChange} error={errors.criterion} />
         
-        <div ref={containerRef} className={`w-full mt-2 transition-all relative ${!isZoomActive && needsZoom ? 'overflow-x-auto flex justify-start pb-12 pt-4 px-4 custom-scrollbar' : 'overflow-visible flex justify-center pb-12 pt-4'}`}>
+        <div ref={containerRef} className={`w-full mt-2 transition-all relative ${!isZoomActive && needsZoom ? 'overflow-x-auto flex justify-start pt-4 px-4 custom-scrollbar' : 'overflow-visible flex justify-center pt-4'}`}>
             <div className={`flex flex-row items-start min-w-max transition-transform duration-500 ease-out px-4 origin-top`} style={{ transform: `scale(${currentScale})`, marginBottom: isZoomActive && currentScale < 1 ? `-${(1 - currentScale) * 300}px` : '0px' }}>
             
                 <div ref={tableRef} className="flex flex-row items-start relative px-10 overflow-visible">
@@ -100,7 +101,7 @@ export default function Step1BaseScale({
         </div>
         
         {/* Generar Gráfica Continua */}
-        <div className="w-full max-w-lg mt-8 pt-6 border-t border-slate-200 flex flex-col items-center z-20 relative bg-white">
+        <div className="w-full max-w-lg mt-6 mb-2 pt-6 border-t border-slate-200 flex flex-col items-center z-20 relative bg-white">
             <button onClick={handleGenerateBaseScale} disabled={isLoading} className={`w-full py-3 text-white text-lg font-bold rounded-xl shadow-md transition-all active:scale-[0.98] ${isLoading ? 'bg-slate-400 cursor-not-allowed' : 'bg-gradient-to-r from-blue-600 to-indigo-600 hover:from-blue-700 hover:to-indigo-700'}`}>
             {isLoading ? 'Calculando...' : 'Generar Gráfica Continua'}
             </button>
diff --git a/frontend/src/components/layout/Footer.jsx b/frontend/src/components/layout/Footer.jsx
index 4bb3a2f..b272700 100644
--- a/frontend/src/components/layout/Footer.jsx
+++ b/frontend/src/components/layout/Footer.jsx
@@ -1,6 +1,6 @@
 export default function Footer() {
   return (
-    <footer className="bg-white border-t border-slate-200 mt-auto shrink-0 w-full pt-12 pb-6">
+    <footer className="bg-white border-t border-slate-200 mt-auto shrink-0 w-full pt-8 pb-8">
       <div className="max-w-7xl mx-auto px-4 sm:px-6 lg:px-8">
         
         <div className="grid grid-cols-1 sm:grid-cols-2 lg:grid-cols-12 gap-8 lg:gap-6">
diff --git a/frontend/src/lib/api.js b/frontend/src/lib/api.js
index 1cabe5d..e94beef 100644
--- a/frontend/src/lib/api.js
+++ b/frontend/src/lib/api.js
@@ -22,12 +22,18 @@ api.interceptors.response.use(
     return response;
   },
   (error) => {
+    // Si es un error 401 (No autorizado)
     if (error.response && error.response.status === 401) {
       localStorage.removeItem('token');
       localStorage.removeItem('user');
-      window.location.href = '/login';
+      
+      // SOLUCIÓN: Solo recargamos y redirigimos si NO estamos ya en /login
+      if (window.location.pathname !== '/login') {
+        window.location.href = '/login';
+      }
     }
-
+    
+    // Propagamos el error para que los componentes puedan leer backendData
     if (error.response && error.response.data) {
         return Promise.reject({ 
             ...error, 
diff --git a/frontend/src/pages/History.jsx b/frontend/src/pages/History.jsx
index 6947934..8dea8b1 100644
--- a/frontend/src/pages/History.jsx
+++ b/frontend/src/pages/History.jsx
@@ -2,6 +2,7 @@ import { useState, useEffect } from 'react';
 import { Link } from 'react-router-dom';
 import { getUserHistory, deleteHistoryItem } from '../services/docService';
 import Step3FinalGraph from '../components/editor/Step3FinalGraph';
+import { FiEye, FiTrash2, FiBarChart2, FiInbox, FiClock } from 'react-icons/fi';
 
 export default function History() {
   const [historyItems, setHistoryItems] = useState([]);
@@ -64,12 +65,13 @@ export default function History() {
       {/* Lista de Historial */}
       {isLoading ? (
         <div className="bg-white p-12 rounded-3xl shadow-sm border border-slate-200 flex flex-col items-center justify-center text-slate-400 border-dashed">
-           <div className="animate-spin text-4xl mb-4">⏳</div>
-           <p className="font-medium">Cargando tus gráficas...</p>
+           <div className="text-6xl"><FiClock className="w-16 h-16 mb-4 opacity-50" strokeWidth={1.5} /></div>
+           <p className="font-medium text-lg">Cargando tus gráficas...</p>
+
         </div>
       ) : historyItems.length === 0 ? (
         <div className="bg-white p-12 rounded-3xl shadow-sm border border-slate-200 flex flex-col items-center justify-center text-slate-400 border-dashed">
-           <span className="text-6xl mb-4">📭</span>
+           <span className="text-6xl"><FiInbox className="w-16 h-16 mb-4 opacity-50" strokeWidth={1.5} /></span>
            <p className="font-medium text-lg">Aún no has guardado ningún modelo.</p>
            <p className="text-sm mt-2">Ve al editor, crea una gráfica y dale a "Guardar".</p>
         </div>
@@ -86,7 +88,7 @@ export default function History() {
                 <div className="p-6 flex flex-col sm:flex-row justify-between items-center gap-4 bg-slate-50/50 rounded-t-2xl">
                   <div className="flex items-center gap-4 w-full sm:w-auto">
                     <div className="w-12 h-12 bg-blue-100 text-blue-600 rounded-full flex items-center justify-center text-xl shadow-inner">
-                      📊
+                      <FiBarChart2 className="w-5 h-5" strokeWidth={2.5} />
                     </div>
                     <div>
                       <h3 className="text-xl font-bold text-slate-800">{item.name || 'Modelo sin título'}</h3>
@@ -111,7 +113,7 @@ export default function History() {
                       className="px-4 py-2.5 bg-white border border-red-200 text-red-500 font-bold rounded-xl hover:bg-red-50 transition-colors shadow-sm"
                       title="Borrar modelo"
                     >
-                      Borrar
+                      <FiTrash2 className="w-5 h-5" strokeWidth={2.5} />
                     </button>
                   </div>
                 </div>
diff --git a/frontend/src/pages/Login.jsx b/frontend/src/pages/Login.jsx
index 8f3ff7a..a119649 100644
--- a/frontend/src/pages/Login.jsx
+++ b/frontend/src/pages/Login.jsx
@@ -2,7 +2,7 @@ import { useState, useEffect, useRef } from 'react';
 import { Link, useNavigate, useSearchParams } from 'react-router-dom';
 import { useAuth } from '../context/AuthContext';
 import { authService } from '../services/authService';
-import EyeIcon from '../components/EyeIcon';
+import { FiEye, FiEyeOff } from 'react-icons/fi';
 
 export default function Login() {
   const [email, setEmail] = useState('');
@@ -70,7 +70,7 @@ export default function Login() {
   };
 
   return (
-    <div className="flex-1 flex items-center justify-center">
+    <div className="flex-1 flex items-center justify-center py-4">
       <div className="max-w-md w-full bg-white p-10 rounded-3xl shadow-sm border border-slate-200">
         
         <div className="text-center mb-8">
@@ -108,7 +108,11 @@ export default function Login() {
                 onClick={() => setShowPassword(!showPassword)}
                 className="absolute right-4 top-1/2 -translate-y-1/2 text-slate-400 hover:text-slate-600 transition-colors focus:outline-none"
               >
-                <EyeIcon isOpen={showPassword} />
+                {showPassword ? (
+                  <FiEye className="w-5 h-5" strokeWidth={2} />
+                ) : (
+                  <FiEyeOff className="w-5 h-5" strokeWidth={2} />
+                )}
               </button>
             </div>
           </div>
diff --git a/frontend/src/pages/Register.jsx b/frontend/src/pages/Register.jsx
index cdc38fc..fc66b73 100644
--- a/frontend/src/pages/Register.jsx
+++ b/frontend/src/pages/Register.jsx
@@ -2,7 +2,7 @@ import { useState } from 'react';
 import { useNavigate, Link } from 'react-router-dom';
 import { useAuth } from '../context/AuthContext';
 import { authService } from '../services/authService';
-import EyeIcon from '../components/EyeIcon';
+import { FiEye, FiEyeOff } from 'react-icons/fi';
 
 export default function Register() {
     const [username, setUsername] = useState('');
@@ -37,7 +37,7 @@ export default function Register() {
     };
 
   return (
-    <div className="flex-1 flex items-center justify-center">
+    <div className="flex-1 flex items-center justify-center py-4">
       <div className="max-w-md w-full bg-white p-10 rounded-3xl shadow-sm border border-slate-200">
         
         <div className="text-center mb-8">
@@ -58,7 +58,7 @@ export default function Register() {
               type="text" required autoComplete="username"
               className="w-full px-5 py-3 rounded-2xl border border-slate-200 focus:ring-2 focus:ring-blue-500 outline-none transition-all bg-slate-50 focus:bg-white"
               value={username} onChange={(e) => setUsername(e.target.value)}
-              placeholder="Ej: usuario99"
+              placeholder="Ej: alexis99"
             />
           </div>
 
@@ -86,7 +86,11 @@ export default function Register() {
                 type="button" onClick={() => setShowPassword(!showPassword)}
                 className="absolute right-4 top-1/2 -translate-y-1/2 text-slate-400 hover:text-slate-600 transition-colors focus:outline-none"
               >
-                <EyeIcon isOpen={showPassword} />
+                {showPassword ? (
+                  <FiEye className="w-5 h-5" strokeWidth={2} />
+                ) : (
+                  <FiEyeOff className="w-5 h-5" strokeWidth={2} />
+                )}
               </button>
             </div>
           </div>
@@ -105,7 +109,11 @@ export default function Register() {
                 type="button" onClick={() => setShowConfirmPassword(!showConfirmPassword)}
                 className="absolute right-4 top-1/2 -translate-y-1/2 text-slate-400 hover:text-slate-600 transition-colors focus:outline-none"
               >
-                <EyeIcon isOpen={showConfirmPassword} />
+                {showConfirmPassword ? (
+                  <FiEye className="w-5 h-5" strokeWidth={2} />
+                ) : (
+                  <FiEyeOff className="w-5 h-5" strokeWidth={2} />
+                )}
               </button>
             </div>
           </div>