add: añadir iconos instalando la librería react-icons para los botones de login y logout.

ajustados márgenes en diferentes vistas para mantener coherencia visual.

frontend/package-lock.json

@@ -12,6 +12,7 @@
         "axios": "^1.13.6",
         "react": "^19.2.4",
         "react-dom": "^19.2.4",
+        "react-icons": "^5.6.0",
         "react-router-dom": "^7.13.2",
         "recharts": "^3.8.0",
         "tailwindcss": "^4.2.2"
@@ -3077,6 +3078,15 @@
         "react": "^19.2.4"
       }
     },
+    "node_modules/react-icons": {
+      "version": "5.6.0",
+      "resolved": "https://registry.npmjs.org/react-icons/-/react-icons-5.6.0.tgz",
+      "integrity": "sha512-RH93p5ki6LfOiIt0UtDyNg/cee+HLVR6cHHtW3wALfo+eOHTp8RnU2kRkI6E+H19zMIs03DyxUG/GfZMOGvmiA==",
+      "license": "MIT",
+      "peerDependencies": {
+        "react": "*"
+      }
+    },
     "node_modules/react-is": {
       "version": "19.2.4",
       "resolved": "https://registry.npmjs.org/react-is/-/react-is-19.2.4.tgz",

frontend/package.json

@@ -14,6 +14,7 @@
     "axios": "^1.13.6",
     "react": "^19.2.4",
     "react-dom": "^19.2.4",
+    "react-icons": "^5.6.0",
     "react-router-dom": "^7.13.2",
     "recharts": "^3.8.0",
     "tailwindcss": "^4.2.2"

frontend/src/components/editor/Step1BaseScale.jsx

@@ -37,7 +37,7 @@ export default function Step1BaseScale({
   const currentScale = isZoomActive && needsZoom ? dynamicScale : 1;
 
   return (
-    <div className="w-full bg-white p-6 rounded-2xl shadow-sm border border-slate-200 mb-6 flex flex-col items-center animate-fade-in relative overflow-visible">
+    <div className="w-full bg-white p-6 rounded-2xl shadow-sm border border-slate-200 flex flex-col items-center animate-fade-in relative overflow-visible">
         
         <div className="flex justify-between items-center w-full mb-4 border-b pb-3 relative z-30">
             <h2 className="text-xl font-bold text-slate-800">

frontend/src/components/editor/Step3FinalGraph.jsx

@@ -19,7 +19,7 @@ const Step3FinalGraph = memo(({ data, criterionName }) => {
   }
 
   return (
-    <div className="w-full h-[550px] mt-2 bg-white p-6 rounded-2xl shadow-sm border border-slate-200 flex flex-col final-graph-container relative">
+    <div className="w-full h-[550px] bg-white p-6 rounded-2xl shadow-sm border border-slate-200 flex flex-col final-graph-container relative">
       <style>{`.final-graph-container svg * { clip-path: none !important; }`}</style>
       
       <h3 className="text-xl font-bold mb-4 text-center text-slate-800 uppercase">

frontend/src/components/layout/Header.jsx

@@ -1,6 +1,7 @@
 import { useState } from 'react';
 import { Link, useNavigate, useLocation } from 'react-router-dom';
 import { useAuth } from '../../context/AuthContext'; 
+import { FiLogIn, FiLogOut } from 'react-icons/fi';
 
 export default function Header() {
   const [isDropdownOpen, setIsDropdownOpen] = useState(false);
@@ -60,8 +61,13 @@ export default function Header() {
                       <p className="text-xs font-bold text-slate-400 uppercase tracking-wider">Usuario</p>
                       <p className="text-sm font-bold text-slate-700 truncate">{user?.username}</p>
                     </div>
-                    <button onClick={handleLogout} className="w-full text-left px-4 py-2 text-sm font-medium text-red-600 hover:bg-red-50 transition-colors">
+                    
-                      🚪 Cerrar Sesión
+                    <button 
+                      onClick={handleLogout} 
+                      className="w-full flex items-center gap-2 px-4 py-2 text-sm font-bold text-red-600 hover:bg-red-50 transition-colors"
+                    >
+                      <FiLogOut className="w-5 h-5" strokeWidth={2.5} />
+                      Cerrar Sesión
                     </button>
                   </div>
                 </>
@@ -69,10 +75,12 @@ export default function Header() {
             </div>
           ) : (
             <div className="flex items-center border-l border-slate-200 pl-4">
+              
               <Link 
                 to="/login" 
-                className="text-sm font-bold bg-blue-600 text-white px-5 py-2.5 rounded-xl shadow-sm hover:bg-blue-700 transition-all active:scale-95"
+                className="flex items-center gap-2 text-sm font-bold bg-blue-600 text-white px-5 py-2.5 rounded-xl shadow-sm hover:bg-blue-700 transition-all active:scale-95"
               >
+                <FiLogIn className="w-5 h-5" strokeWidth={2.5} />
                 Acceder
               </Link>
             </div>

frontend/src/pages/DocEditor.jsx

@@ -248,7 +248,7 @@ export default function DocEditor() {
       )}
 
       {step === 3 && finalResult && (
-        <div className="flex flex-col gap-6 w-full">
+        <div className="flex flex-col w-full">
           <Step3FinalGraph data={finalResult} criterionName={criterionName} />
 
           <button 

frontend/src/pages/History.jsx

@@ -44,7 +44,7 @@ export default function History() {
   };
 
   return (
-    <div className="w-full max-w-7xl mx-auto flex flex-col gap-8 animate-fade-in pb-12">      
+    <div className="w-full max-w-7xl mx-auto flex flex-col gap-8 animate-fade-in pb-2">      
       {/* Cabecera */}
       <div className="flex justify-between items-center bg-white p-8 rounded-3xl shadow-sm border border-slate-200">
         <div>