diff --git a/src/index.html b/src/index.html
index 993ded9..39fadcf 100644
--- a/src/index.html
+++ b/src/index.html
@@ -8,6 +8,7 @@
   </head>
 
   <body>
+    <div id="progress-bar"></div>
     <header id="site-header">
       <nav id="main-nav">
         <a href="#" class="nav-logo">Brew<span>Box</span></a>
@@ -135,6 +136,14 @@
             Completá el formulario y recibís tu primer envío en menos de 72hs.
             Estudiantes obtienen un descuento del 20%.
           </p>
+          <div class="plan-preview" id="plan-preview">
+            <div class="plan-preview-inner">
+              <span class="plan-preview-label">Plan seleccionado</span>
+              <span class="plan-preview-name" id="plan-preview-name">—</span>
+              <span class="plan-preview-price" id="plan-preview-price"></span>
+              <ul class="plan-preview-features" id="plan-preview-features"></ul>
+            </div>
+          </div>
         </div>
 
         <form action="#" method="post">
@@ -144,15 +153,24 @@
               <div class="field-group">
                 <label for="name">Nombre</label>
                 <input type="text" id="name" name="name" required />
+                <span class="field-error-msg"
+                  >Ingresá al menos 2 caracteres</span
+                >
               </div>
               <div class="field-group">
                 <label for="lastname">Apellido</label>
                 <input type="text" id="lastname" name="lastname" required />
+                <span class="field-error-msg"
+                  >Ingresá al menos 2 caracteres</span
+                >
               </div>
             </div>
             <div class="field-group">
               <label for="email">Correo electrónico</label>
               <input type="email" id="email" name="email" required />
+              <span class="field-error-msg"
+                >Ingresá un correo electrónico válido</span
+              >
             </div>
             <div class="field-group checkbox-group">
               <input type="checkbox" id="student" name="student" />
@@ -178,6 +196,7 @@
             <div class="field-group">
               <label for="reason">¿Por qué te suscribís?</label>
               <textarea id="reason" name="reason" rows="4"></textarea>
+              <span class="char-counter" id="reason-counter">0 / 300</span>
             </div>
           </fieldset>
 
@@ -191,6 +210,16 @@
                 <option value="debit">Tarjeta de débito</option>
               </select>
             </div>
+            <div class="field-group" id="cuotas-group" style="display: none">
+                <label for="cuotas">Cantidad de cuotas</label>
+                <input
+                  type="number"
+                  id="cuotas"
+                  name="cuotas"
+                  min="1"
+                  max="12"
+                  placeholder="1"
+                />
             <div class="field-group field-group--icon">
               <label for="card">Número de tarjeta</label>
               <div class="input-icon-wrapper">
@@ -213,10 +242,12 @@
                   type="text"
                   id="card"
                   name="card"
-                  placeholder="1234 5678 9012 3456"
+                  placeholder="XXXX-XXXX-XXXX-XXXX"
                   required
                 />
+                <span class="card-brand" id="card-brand"></span>
               </div>
+              <span class="field-error-msg">Número de tarjeta inválido</span>
             </div>
             <div class="field-row">
               <div class="field-group">
@@ -228,6 +259,7 @@
                   placeholder="MM/AA"
                   required
                 />
+                <span class="field-error-msg">Formato MM/AA</span>
               </div>
               <div class="field-group">
                 <label for="cvv">CVV</label>
@@ -238,6 +270,7 @@
                   placeholder="123"
                   required
                 />
+                <span class="field-error-msg">Ingresá un CVV válido</span>
               </div>
             </div>
           </fieldset>
@@ -314,6 +347,31 @@
             <button type="submit" class="cta-button">Suscribirme</button>
           </div>
         </form>
+        <div id="form-confirmation">
+          <div class="confirmation-icon">
+            <svg
+              xmlns="http://www.w3.org/2000/svg"
+              width="20"
+              height="20"
+              viewBox="0 0 24 24"
+              fill="none"
+              stroke="currentColor"
+              stroke-width="1.5"
+              stroke-linecap="round"
+              stroke-linejoin="round"
+            >
+              <polyline points="20 6 9 17 4 12"></polyline>
+            </svg>
+          </div>
+          <p class="confirmation-title">¡Bienvenido a BrewBox!</p>
+          <p class="confirmation-text">
+            Tu suscripción fue registrada. En las próximas horas vas a recibir
+            un email de confirmación con los detalles de tu primer envío.
+          </p>
+          <p class="confirmation-detail">
+            Primer envío estimado: <span id="confirm-date"></span>
+          </p>
+        </div>
       </section>
     </main>
 
diff --git a/src/script.js b/src/script.js
index e69de29..2e5b879 100644
--- a/src/script.js
+++ b/src/script.js
@@ -0,0 +1,308 @@
+// Smooth scrolling for anchor links
+document.querySelectorAll('a[href^="#"]').forEach(anchor => {
+    anchor.addEventListener('click', function(e) {
+        e.preventDefault();
+        const target = document.querySelector(this.getAttribute('href'));
+        if (target) {
+            target.scrollIntoView({ behavior: 'smooth' });
+        }
+    });
+});
+
+// Scroll progress bar
+const progressBar = document.getElementById('progress-bar');
+
+window.addEventListener('scroll', () => {
+    const scrollTop = window.scrollY;
+    const docHeight = document.documentElement.scrollHeight - window.innerHeight;
+    const progress = (scrollTop / docHeight) * 100;
+    progressBar.style.width = progress + '%';
+});
+
+// Student discount logic
+const studentCheckbox = document.getElementById('student');
+
+const plans = {
+    normal:  { full: 10, label: 'Normal' },
+    premium: { full: 15, label: 'Premium' }
+};
+
+function updatePrices() {
+    const isStudent = studentCheckbox.checked;
+
+    document.querySelectorAll('.radio-group label').forEach(lbl => {
+        const input = lbl.querySelector('input[type="radio"]');
+        if (!input) return;
+
+        const plan = plans[input.value];
+        if (!plan) return;
+
+        const discounted = (plan.full * 0.7).toFixed(2);
+
+        if (isStudent) {
+            lbl.innerHTML = `
+                <input type="radio" name="plan" value="${input.value}" ${input.checked ? 'checked' : ''} ${input.required ? 'required' : ''}>
+                ${plan.label} —
+                <span class="price-original">$${plan.full}/mes</span>
+                <span class="price-discount">20% OFF</span>
+                <span class="price-new">$${discounted}/mes</span>
+            `;
+        } else {
+            lbl.innerHTML = `
+                <input type="radio" name="plan" value="${input.value}" ${input.checked ? 'checked' : ''} ${input.required ? 'required' : ''}>
+                ${plan.label} — $${plan.full}/mes
+            `;
+        }
+    });
+}
+
+studentCheckbox.addEventListener('change', updatePrices);
+
+// Character counter for textarea
+const textarea = document.getElementById('reason');
+const counter = document.getElementById('reason-counter');
+const MAX_CHARS = 300;
+
+textarea.addEventListener('input', () => {
+    const len = textarea.value.length;
+    counter.textContent = `${len} / ${MAX_CHARS}`;
+
+    counter.classList.remove('near-limit', 'at-limit');
+
+    if (len >= MAX_CHARS) {
+        textarea.value = textarea.value.slice(0, MAX_CHARS);
+        counter.classList.add('at-limit');
+    } else if (len >= MAX_CHARS * 0.8) {
+        counter.classList.add('near-limit');
+    }
+});
+
+// Form validation
+function setFieldState(input, isValid) {
+    const group = input.closest('.field-group');
+    if (!group) return;
+    group.classList.remove('error', 'success');
+    if (input.value.trim() === '') return;
+    group.classList.add(isValid ? 'success' : 'error');
+}
+
+// Name and Lastname
+['name', 'lastname'].forEach(id => {
+    document.getElementById(id).addEventListener('input', function() {
+        setFieldState(this, this.value.trim().length >= 2);
+    });
+});
+
+// Email
+document.getElementById('email').addEventListener('input', function() {
+    const valid = /^[^\s@]+@[^\s@]+\.[^\s@]+$/.test(this.value);
+    setFieldState(this, valid);
+});
+
+// MMAA validation
+document.getElementById('expiry').addEventListener('input', function() {
+    this.value = this.value.replace(/[^\d]/g, '').slice(0, 4);
+    if (this.value.length > 2) {
+        this.value = this.value.slice(0, 2) + '/' + this.value.slice(2);
+    }
+    const valid = /^(0[1-9]|1[0-2])\/\d{2}$/.test(this.value);
+    setFieldState(this, valid);
+});
+
+// CVV
+document.getElementById('cvv').addEventListener('input', function() {
+    this.value = this.value.replace(/\D/g, '').slice(0, 4);
+    setFieldState(this, this.value.length >= 3);
+});
+
+
+// Plan preview logic
+const planData = {
+    normal: {
+        name: 'Normal',
+        price: '$10/mes',
+        priceStudent: '$7.00/mes',
+        features: [
+            '250 g por envío',
+            '1 café de origen único por mes',
+            'Envío gratuito',
+            'Guía de preparación'
+        ]
+    },
+    premium: {
+        name: 'Premium',
+        price: '$15/mes',
+        priceStudent: '$10.50/mes',
+        features: [
+            '500 g por envío',
+            '2 cafés de origen único por mes',
+            'Envío gratuito',
+            'Guía de preparación',
+            'Acceso a lotes exclusivos'
+        ]
+    }
+};
+
+const planPreview     = document.getElementById('plan-preview');
+const planPreviewName = document.getElementById('plan-preview-name');
+const planPreviewPrice = document.getElementById('plan-preview-price');
+const planPreviewFeatures = document.getElementById('plan-preview-features');
+
+function updatePlanPreview() {
+    const selected = document.querySelector('input[name="plan"]:checked');
+    if (!selected) {
+        planPreview.classList.remove('visible');
+        return;
+    }
+
+    const plan = planData[selected.value];
+    const isStudent = document.getElementById('student').checked;
+
+    planPreviewName.textContent = plan.name;
+    planPreviewPrice.textContent = isStudent ? plan.priceStudent : plan.price;
+
+    planPreviewFeatures.innerHTML = plan.features
+        .map(f => `<li>${f}</li>`)
+        .join('');
+
+    planPreview.classList.add('visible');
+}
+
+document.querySelectorAll('input[name="plan"]').forEach(radio => {
+    radio.addEventListener('change', updatePlanPreview);
+});
+
+// Update prices and preview when student checkbox changes
+studentCheckbox.addEventListener('change', () => {
+    updatePrices();
+    updatePlanPreview();
+});
+
+// Credit card validation and brand detection
+const cardInput = document.getElementById('card');
+const cardBrand = document.getElementById('card-brand');
+
+const cardPatterns = {
+    Visa:       /^4/,
+    Mastercard: /^5[1-5]|^2[2-7]/,
+    Amex:       /^3[47]/,
+    Naranja:    /^589562/,
+    Cabal:      /^604201|^589657/,
+};
+
+function detectCardBrand(number) {
+    const clean = number.replace(/\s/g, '');
+    for (const [brand, pattern] of Object.entries(cardPatterns)) {
+        if (pattern.test(clean)) return brand;
+    }
+    return null;
+}
+
+function validateCard(number) {
+    const clean = number.replace(/\s/g, '');
+    if (clean.length < 13) return false;
+
+    // Luhn algorithm
+    let sum = 0;
+    let alternate = false;
+    for (let i = clean.length - 1; i >= 0; i--) {
+        let n = parseInt(clean[i]);
+        if (alternate) {
+            n *= 2;
+            if (n > 9) n -= 9;
+        }
+        sum += n;
+        alternate = !alternate;
+    }
+    return sum % 10 === 0;
+}
+
+cardInput.addEventListener('input', function() {
+    // Remove non-digits and limit to 16 characters
+    let val = this.value.replace(/\D/g, '').slice(0, 16);
+    this.value = val.replace(/(.{4})/g, '$1 ').trim();
+
+    const brand = detectCardBrand(this.value);
+    const valid = validateCard(this.value);
+
+    if (brand) {
+        cardBrand.textContent = brand;
+        cardBrand.classList.add('visible');
+    } else {
+        cardBrand.classList.remove('visible');
+    }
+
+    setFieldState(this, valid);
+});
+
+// Payment cuotas logic
+const paymentSelect = document.getElementById('payment');
+const cuotasGroup = document.getElementById('cuotas-group');
+const cuotasInput = document.getElementById('cuotas');
+
+paymentSelect.addEventListener('change', function() {
+    if (this.value === 'credit') {
+        cuotasGroup.style.display = 'flex';
+        cuotasInput.setAttribute('required', '');
+    } else {
+        cuotasGroup.style.display = 'none';
+        cuotasInput.removeAttribute('required');
+        cuotasInput.value = '';
+    }
+});
+
+// Cuotas validation
+cuotasInput.addEventListener('input', function() {
+    const val = parseInt(this.value);
+    setFieldState(this, val >= 1 && val <= 12);
+});
+
+// Form submission logic
+const form = document.querySelector('form');
+const submitBtn = document.querySelector('.cta-button[type="submit"]');
+const confirmation = document.getElementById('form-confirmation');
+const confirmDate = document.getElementById('confirm-date');
+const subsCounter = document.querySelector('.hero-stats .stat-item:last-child .stat-number');
+
+form.addEventListener('submit', function(e) {
+    e.preventDefault();
+
+    // loading state
+    submitBtn.classList.add('loading');
+    submitBtn.innerHTML = '<span class="spinner"></span> Procesando...';
+
+    setTimeout(() => {
+        // Hidden form
+        form.style.transition = 'opacity 0.3s ease';
+        form.style.opacity = '0';
+
+        setTimeout(() => {
+            form.style.display = 'none';
+
+            // Calculate delivery date (7 days from now)
+            const delivery = new Date();
+            delivery.setDate(delivery.getDate() + 7);
+            confirmDate.textContent = delivery.toLocaleDateString('es-AR', {
+                day: 'numeric',
+                month: 'long',
+                year: 'numeric'
+            });
+
+            // Show confirmation
+            confirmation.style.display = 'flex';
+            requestAnimationFrame(() => {
+                requestAnimationFrame(() => {
+                    confirmation.classList.add('visible');
+                });
+            });
+
+            // +1 to subscriber counter
+            if (subsCounter) {
+                const current = parseInt(subsCounter.textContent);
+                subsCounter.textContent = current + 1;
+            }
+
+        }, 300);
+
+    }, 2000); // simulate processing delay
+});
\ No newline at end of file
diff --git a/src/styles.css b/src/styles.css
index e090f7a..ddfbb33 100644
--- a/src/styles.css
+++ b/src/styles.css
@@ -23,6 +23,16 @@ a {
     color: inherit;
 }
 
+input[type="number"]::-webkit-outer-spin-button,
+input[type="number"]::-webkit-inner-spin-button {
+    -webkit-appearance: none;
+    margin: 0;
+}
+
+input[type="number"] {
+    -moz-appearance: textfield;
+}
+
 /* Navbar */
 #site-header {
     position: sticky;
@@ -537,6 +547,7 @@ label {
 
 input[type="text"],
 input[type="email"],
+input[type="number"],
 textarea,
 select {
     background: rgba(255, 255, 255, 0.04);
@@ -595,6 +606,7 @@ textarea {
     display: flex;
     align-items: center;
     gap: 0.6rem;
+    flex-wrap: wrap;
     font-size: 0.88rem;
     letter-spacing: 0.03em;
     text-transform: none;
@@ -735,6 +747,238 @@ textarea {
     }
 }
 
+.price-original {
+    text-decoration: line-through;
+    color: rgba(245, 240, 232, 0.25);
+    font-size: 0.85rem;
+}
+
+.price-discount {
+    color: #c8a96e;
+    font-size: 0.72rem;
+    letter-spacing: 0.1em;
+    border: 1px solid rgba(200, 169, 110, 0.3);
+    padding: 0.1rem 0.4rem;
+    border-radius: 2px;
+    white-space: nowrap;
+}
+
+.price-new {
+    color: #f5f0e8;
+    font-size: 0.95rem;
+}
+
+.char-counter {
+    font-size: 0.68rem;
+    letter-spacing: 0.08em;
+    color: rgba(245, 240, 232, 0.2);
+    text-align: right;
+    transition: color 0.2s;
+}
+
+.char-counter.near-limit {
+    color: #c8a96e;
+}
+
+.char-counter.at-limit {
+    color: rgba(220, 80, 80, 0.7);
+}
+
+.field-group.error input,
+.field-group.error textarea,
+.field-group.error select {
+    border-bottom-color: rgba(220, 80, 80, 0.6);
+    background: rgba(220, 80, 80, 0.04);
+}
+
+.field-group.success input,
+.field-group.success textarea,
+.field-group.success select {
+    border-bottom-color: rgba(100, 200, 130, 0.5);
+    background: rgba(100, 200, 130, 0.03);
+}
+
+.field-error-msg {
+    font-size: 0.68rem;
+    letter-spacing: 0.05em;
+    color: rgba(220, 80, 80, 0.7);
+    margin-top: 0.25rem;
+    display: none;
+}
+
+.field-group.error .field-error-msg {
+    display: block;
+}
+
+.plan-preview {
+    margin-top: 2rem;
+    border-top: 1px solid rgba(255, 255, 255, 0.06);
+    padding-top: 1.5rem;
+    opacity: 0;
+    transform: translateY(8px);
+    transition: opacity 0.3s ease, transform 0.3s ease;
+    pointer-events: none;
+}
+
+.plan-preview.visible {
+    opacity: 1;
+    transform: translateY(0);
+    pointer-events: auto;
+}
+
+.plan-preview-label {
+    display: block;
+    font-size: 0.65rem;
+    letter-spacing: 0.2em;
+    text-transform: uppercase;
+    color: rgba(245, 240, 232, 0.25);
+    margin-bottom: 0.5rem;
+}
+
+.plan-preview-name {
+    display: block;
+    font-size: 1.3rem;
+    font-weight: normal;
+    color: #f5f0e8;
+    margin-bottom: 0.25rem;
+}
+
+.plan-preview-price {
+    display: block;
+    font-size: 0.85rem;
+    color: #c8a96e;
+    margin-bottom: 1.25rem;
+    letter-spacing: 0.05em;
+}
+
+.plan-preview-features {
+    list-style: none;
+    display: flex;
+    flex-direction: column;
+    gap: 0.6rem;
+}
+
+.plan-preview-features li {
+    display: flex;
+    align-items: flex-start;
+    gap: 0.75rem;
+    font-size: 0.8rem;
+    color: rgba(245, 240, 232, 0.45);
+    line-height: 1.4;
+}
+
+.plan-preview-features li::before {
+    content: '';
+    display: block;
+    width: 12px;
+    min-width: 12px;
+    height: 1px;
+    background: #c8a96e;
+    margin-top: 0.65em;
+}
+
+.card-brand {
+    position: absolute;
+    right: 0.75rem;
+    font-size: 0.65rem;
+    letter-spacing: 0.1em;
+    text-transform: uppercase;
+    color: #c8a96e;
+    opacity: 0;
+    transition: opacity 0.2s;
+    pointer-events: none;
+}
+
+.card-brand.visible {
+    opacity: 1;
+}
+
+/* Loading State */
+.spinner {
+    width: 18px;
+    height: 18px;
+    border: 2px solid rgba(10, 10, 10, 0.3);
+    border-top-color: #0a0a0a;
+    border-radius: 50%;
+    animation: spin 0.7s linear infinite;
+    display: inline-block;
+    vertical-align: middle;
+    margin-right: 0.5rem;
+}
+
+@keyframes spin {
+    to { transform: rotate(360deg); }
+}
+
+.cta-button.loading {
+    opacity: 0.8;
+    cursor: not-allowed;
+    pointer-events: none;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    gap: 0.5rem;
+}
+
+/* Confirmación */
+#form-confirmation {
+    display: none;
+    flex-direction: column;
+    gap: 1.5rem;
+    padding: 3rem 0;
+    opacity: 0;
+    transform: translateY(12px);
+    transition: opacity 0.4s ease, transform 0.4s ease;
+}
+
+#form-confirmation.visible {
+    opacity: 1;
+    transform: translateY(0);
+}
+
+.confirmation-icon {
+    width: 48px;
+    height: 48px;
+    border: 1px solid rgba(200, 169, 110, 0.3);
+    border-radius: 50%;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+}
+
+.confirmation-icon svg {
+    color: #c8a96e;
+}
+
+.confirmation-title {
+    font-size: 1.8rem;
+    font-weight: normal;
+    color: #f5f0e8;
+    letter-spacing: -0.01em;
+    line-height: 1.2;
+}
+
+.confirmation-text {
+    font-size: 0.9rem;
+    line-height: 1.8;
+    color: rgba(245, 240, 232, 0.4);
+    max-width: 38ch;
+}
+
+.confirmation-detail {
+    font-size: 0.72rem;
+    letter-spacing: 0.1em;
+    text-transform: uppercase;
+    color: rgba(245, 240, 232, 0.2);
+    border-top: 1px solid rgba(255, 255, 255, 0.06);
+    padding-top: 1.5rem;
+}
+
+.confirmation-detail span {
+    color: #c8a96e;
+}
+
+
 /* Footer */
 
 #site-footer {
@@ -801,4 +1045,15 @@ textarea {
     .footer-links {
         gap: 1.25rem;
     }
+}
+
+#progress-bar {
+    position: fixed;
+    top: 0;
+    left: 0;
+    width: 0%;
+    height: 2px;
+    background: #c8a96e;
+    z-index: 9999;
+    transition: width 0.1s linear;
 }
\ No newline at end of file
