* { margin: 0; padding: 0; box-sizing: border-box; }
body {
  font-family: Arial, sans-serif;
  line-height: 1.6;
  overflow-x: hidden;
  background: #fff;
}

/* Animaciones */
@keyframes fadeUp {
  0% { opacity: 0; transform: translateY(30px); }
  100% { opacity: 1; transform: translateY(0); }
}

.animate { opacity: 0; animation: fadeUp 0.8s ease forwards; }
.delay-1 { animation-delay: 0.3s; }
.delay-2 { animation-delay: 0.6s; }
.delay-3 { animation-delay: 0.9s; }

/* Hero */
.hero {
  min-height: 100vh;
  background: #2c2c2c;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  color: white;
  flex-direction: column;
}
.product-image {
  width: 250px; height: 250px; background: #f0f0f0; border-radius: 20px;
  margin: 0 auto 20px; display: flex; align-items: center; justify-content: center;
  box-shadow: 0 10px 20px rgba(0,0,0,0.3);
}
.product-title { font-size: 2.5rem; margin: 20px 0; }
.product-price { font-size: 1.8rem; margin-bottom: 20px; }
.buy-button {
  background: #b0b0b0; border: none; color: white; padding: 12px 30px;
  border-radius: 25px; cursor: pointer; transition: transform .2s;
}
.buy-button:hover { background: #a0a0a0; transform: scale(1.05); }

/* Navbar */
.navbar {
  position: fixed; top: -70px; left: 0; right: 0;
  background: white; border-bottom: 1px solid #eee;
  transition: top .3s; padding: 10px 30px;
  z-index: 100; display: flex; justify-content: space-between; align-items: center;
}
.navbar.visible { top: 0; }
.nav-title { font-weight: bold; color: #333; }
.nav-buy-button {
  background: #b0b0b0; border: none; color: white; padding: 8px 20px;
  border-radius: 20px; cursor: pointer; transition: transform .2s;
}
.nav-buy-button:hover { background: #a0a0a0; transform: scale(1.05); }

/* Botón menú */
.menu-button {
  position: fixed; top: 20px; left: 20px; z-index: 1001;
  background: white; border: none; width: 40px; height: 40px;
  border-radius: 8px; cursor: pointer; transition: top .3s;
}
.menu-button.shifted { top: 80px; }

/* Sidebar */
.sidebar {
  position: fixed; top: 0; left: -250px; width: 250px; height: 100vh;
  background: #fff; box-shadow: 2px 0 8px rgba(0,0,0,0.1);
  transition: left .3s; z-index: 1000; padding: 60px 20px;
}
.sidebar.open { left: 0; }
.sidebar a {
  display: block; padding: 12px 0; color: #333; text-decoration: none;
}
.sidebar a:hover { color: #b0b0b0; }

/* Overlay */
.overlay {
  position: fixed; top:0; left:0; width:100%; height:100%;
  background: rgba(0,0,0,0.3); opacity:0; visibility:hidden;
  transition:.3s; z-index: 500;
}
.overlay.active { opacity:1; visibility:visible; }

/* Sección detalles */
.details { padding: 60px 20px; background: #fff; }
.details-content {
  max-width: 900px; margin: auto; display: grid;
  grid-template-columns: 1fr 1fr; gap: 40px;
}
.details h2 { margin-bottom: 15px; }
.features { list-style: none; }
.features li { margin: 8px 0; }
.details-image {
  background: #f5f5f5; height: 300px;
  display: flex; justify-content: center; align-items: center;
}

/* Footer */
.footer { background: #2c2c2c; color: white; text-align: center; padding: 30px; }

/* Responsive */
@media (max-width: 768px) {
  .details-content { grid-template-columns: 1fr; text-align: center; }
  .navbar { flex-direction: column; gap: 10px; }
}


/* Formulario de compra */
.purchase-form-overlay {
  position: fixed;
  top: 0; left: 0; width: 100%; height: 100%;
  background: rgba(0,0,0,0.5);
  display: flex; align-items: center; justify-content: center;
  z-index: 2000; opacity: 0; visibility: hidden;
  transition: all 0.3s ease;
}
.purchase-form-overlay.active { opacity: 1; visibility: visible; }
.purchase-form {
  background: white; padding: 40px; border-radius: 20px;
  box-shadow: 0 20px 40px rgba(0,0,0,0.3);
  max-width: 500px; width: 90%;
  max-height: 90vh; overflow-y: auto;
  transform: translateY(-50px); transition: transform 0.3s ease;
}
.purchase-form-overlay.active .purchase-form { transform: translateY(0); }
.form-header { text-align: center; margin-bottom: 30px; }
.form-title { font-size: 1.8rem; color: #2c2c2c; margin-bottom: 10px; }
.form-subtitle { color: #666; font-size: 1rem; }
.form-group { margin-bottom: 20px; }
.form-label {
  display: block; margin-bottom: 8px; color: #333;
  font-weight: 500; text-transform: uppercase;
  font-size: 0.9rem; letter-spacing: 0.5px;
}
.form-input {
  width: 100%; padding: 12px 15px; border: 2px solid #f0f0f0;
  border-radius: 10px; font-size: 1rem; background: #fafafa;
  transition: border-color 0.3s, box-shadow 0.3s;
}
.form-input:focus {
  outline: none; border-color: #b0b0b0;
  box-shadow: 0 0 0 3px rgba(176,176,176,0.1);
  background: white;
}
.form-buttons { display: flex; gap: 15px; margin-top: 30px; }
.form-button {
  flex: 1; padding: 15px; border: none; border-radius: 25px;
  font-size: 1rem; cursor: pointer; transition: all 0.2s;
  font-weight: 500; text-transform: uppercase; letter-spacing: 0.5px;
}
.form-button-primary { background: #b0b0b0; color: white; }
.form-button-primary:hover {
  background: #a0a0a0; transform: translateY(-2px);
  box-shadow: 0 5px 15px rgba(176,176,176,0.3);
}
.form-button-secondary { background: #f0f0f0; color: #666; }
.form-button-secondary:hover { background: #e0e0e0; transform: translateY(-2px); }
.close-button {
  position: absolute; top: 15px; right: 20px;
  background: none; border: none; font-size: 24px;
  color: #999; cursor: pointer; transition: color 0.2s;
}
.close-button:hover { color: #666; }

@media (max-width: 768px) {
  .purchase-form { padding: 30px 20px; margin: 10px; }
  .form-buttons { flex-direction: column; }
}