/* Flech - Estilos principales */
:root {
  --blue-primary: #3B82F6;
  --blue-light: #E0F2FE;
  --blue-bg: #F0F9FF;
  --blue-dark: #1e3a5f;
  --text-dark: #1e293b;
  --text-muted: #64748b;
  --white: #ffffff;
  --footer-bg: #0f172a;
  --disclaimer-bg: #fef3c7;
  --disclaimer-border: #f59e0b;
  --ad-badge: #dc2626;
  --radius: 16px;
  --radius-sm: 12px;
  --shadow: 0 4px 24px rgba(59, 130, 246, 0.08);
  --shadow-hover: 0 12px 40px rgba(59, 130, 246, 0.15);
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
  color: var(--text-dark);
  background: var(--white);
  overflow-x: hidden;
  padding-top: 36px; /* espacio para la placa PUBLICIDAD */
}

/* Ad plaque - siempre visible */
.ad-badge {
  position: fixed;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  z-index: 9999;
  background: var(--ad-badge);
  color: white;
  padding: 6px 20px;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.05em;
  border-radius: 0 0 var(--radius-sm) var(--radius-sm);
  box-shadow: 0 4px 12px rgba(220, 38, 38, 0.4);
  animation: slideDown 0.6s ease-out, pulse 3s ease-in-out 1s infinite;
}

@keyframes slideDown {
  from { transform: translateX(-50%) translateY(-100%); opacity: 0; }
  to { transform: translateX(-50%) translateY(0); opacity: 1; }
}

@keyframes pulse {
  0%, 100% { box-shadow: 0 4px 12px rgba(220, 38, 38, 0.4); }
  50% { box-shadow: 0 4px 20px rgba(220, 38, 38, 0.6); }
}

/* Disclaimer - color brillante */
.disclaimer-banner {
  background: linear-gradient(135deg, #fef3c7 0%, #fde68a 50%, #fcd34d 100%);
  border: 2px solid var(--disclaimer-border);
  color: #92400e;
  padding: 14px 24px;
  text-align: center;
  font-size: 14px;
  font-weight: 600;
  margin: 0;
  position: relative;
  z-index: 100;
  animation: fadeIn 0.8s ease-out;
  box-shadow: 0 2px 12px rgba(245, 158, 11, 0.3);
}

.disclaimer-banner strong { color: #b45309; }

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(-10px); }
  to { opacity: 1; transform: translateY(0); }
}

/* Header */
.header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(0,0,0,0.06);
  padding: 16px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: 1200px;
  margin: 0 auto;
  transition: box-shadow 0.25s ease, border-bottom-color 0.25s ease, background 0.25s ease;
}

.header.scrolled {
  background: rgba(255,255,255,0.98);
  box-shadow: 0 4px 24px rgba(0,0,0,0.08);
  border-bottom-color: rgba(0,0,0,0.1);
}

.logo {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--blue-primary);
  display: flex;
  align-items: center;
  gap: 8px;
}

.logo-icon {
  width: 32px;
  height: 32px;
  background: linear-gradient(135deg, var(--blue-primary), #60a5fa);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 14px;
}

.nav {
  display: flex;
  align-items: center;
  gap: 32px;
}

.nav a {
  color: var(--text-dark);
  text-decoration: none;
  font-weight: 500;
  transition: color 0.2s, transform 0.2s;
}

.nav a:hover {
  color: var(--blue-primary);
  transform: translateY(-1px);
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 20px;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 14px;
  cursor: pointer;
  transition: all 0.3s ease;
  text-decoration: none;
  border: none;
}

.btn-primary {
  background: var(--blue-primary);
  color: white;
  box-shadow: 0 4px 14px rgba(59, 130, 246, 0.4);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(59, 130, 246, 0.5);
}

.btn-secondary {
  background: white;
  color: var(--blue-primary);
  border: 2px solid var(--blue-primary);
}

.btn-secondary:hover {
  background: var(--blue-light);
  transform: translateY(-2px);
}

/* Hero */
.hero {
  background: linear-gradient(180deg, var(--blue-bg) 0%, var(--white) 70%);
  padding: 60px 24px 80px;
  position: relative;
  overflow: hidden;
  max-width: none;
  width: 100%;
}

.hero::before,
.hero::after {
  content: '';
  position: absolute;
  width: 400px;
  height: 400px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(59, 130, 246, 0.12) 0%, transparent 70%);
  animation: float 8s ease-in-out infinite;
}

.hero::before { top: -100px; left: -100px; animation-delay: 0s; }
.hero::after { bottom: -100px; right: -100px; animation-delay: -4s; }

@keyframes float {
  0%, 100% { transform: translate(0, 0) scale(1); }
  50% { transform: translate(20px, -20px) scale(1.05); }
}

.hero-inner {
  max-width: 720px;
  margin: 0 auto;
  text-align: center;
  position: relative;
  z-index: 1;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: white;
  padding: 8px 16px;
  border-radius: 999px;
  font-size: 13px;
  color: var(--text-muted);
  margin-bottom: 24px;
  box-shadow: var(--shadow);
  animation: fadeInUp 0.8s ease-out 0.2s both;
}

.hero h1 {
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 20px;
  color: var(--text-dark);
  animation: fadeInUp 0.8s ease-out 0.3s both;
}

.hero p {
  font-size: 1.1rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 32px;
  animation: fadeInUp 0.8s ease-out 0.4s both;
}

.hero-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  justify-content: center;
  animation: fadeInUp 0.8s ease-out 0.5s both;
}

.hero-cta input {
  padding: 14px 20px;
  border: 2px solid #e2e8f0;
  border-radius: var(--radius-sm);
  font-size: 16px;
  min-width: 260px;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.hero-cta input:focus {
  outline: none;
  border-color: var(--blue-primary);
  box-shadow: 0 0 0 4px rgba(59, 130, 246, 0.15);
}

.hero-cta .btn {
  animation: subtlePulse 2.5s ease-in-out infinite;
}

@keyframes subtlePulse {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.02); }
}

@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(24px); }
  to { opacity: 1; transform: translateY(0); }
}

/* Sections common */
section {
  max-width: 1200px;
  margin: 0 auto;
  padding: 80px 24px;
}

.section-title {
  font-size: clamp(1.75rem, 4vw, 2.25rem);
  font-weight: 800;
  margin-bottom: 48px;
  text-align: center;
  color: var(--text-dark);
}

/* How it works / Steps */
.steps-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
}

.step-card {
  background: white;
  border-radius: var(--radius);
  padding: 32px;
  box-shadow: var(--shadow);
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  opacity: 0;
  transform: translateY(30px);
}

.step-card.visible {
  opacity: 1;
  transform: translateY(0);
}

.step-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-hover);
}

.step-card .icon-wrap {
  width: 56px;
  height: 56px;
  background: var(--blue-light);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  margin-bottom: 20px;
}

.step-card .step-num {
  font-size: 12px;
  font-weight: 700;
  color: var(--blue-primary);
  letter-spacing: 0.05em;
  margin-bottom: 8px;
}

.step-card h3 {
  font-size: 1.25rem;
  margin-bottom: 12px;
  color: var(--text-dark);
}

.step-card p {
  color: var(--text-muted);
  line-height: 1.6;
  font-size: 15px;
}

/* Features */
.feature-block {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
  margin-bottom: 80px;
}

.feature-block:nth-child(even) {
  direction: rtl;
}

.feature-block:nth-child(even) > * {
  direction: ltr;
}

.feature-content h3 {
  font-size: 1.5rem;
  margin-bottom: 16px;
  color: var(--text-dark);
}

.feature-content p {
  color: var(--text-muted);
  line-height: 1.7;
  margin-bottom: 24px;
}

.feature-visual {
  background: white;
  border-radius: var(--radius);
  padding: 32px;
  box-shadow: var(--shadow);
  transition: transform 0.4s ease;
}

.feature-block:hover .feature-visual {
  transform: scale(1.02);
}

.feature-visual--product {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0;
  background: transparent;
  box-shadow: none;
  border: none;
}

.feature-visual--product .product-img {
  width: 100%;
  max-width: 400px;
  height: auto;
  aspect-ratio: 1;
  object-fit: contain;
  border-radius: 24px;
  display: block;
}

.feature-content-btns {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 24px;
}

.feature-content-btns .btn {
  flex: 0 1 auto;
  min-width: 120px;
  justify-content: center;
}

/* Testimonials */
.testimonials-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 24px;
}

.testimonial-card {
  background: white;
  border-radius: var(--radius);
  padding: 28px;
  box-shadow: var(--shadow);
  transition: all 0.3s ease;
  opacity: 0;
  transform: translateY(20px);
}

.testimonial-card.visible {
  opacity: 1;
  transform: translateY(0);
}

.testimonial-card:hover {
  box-shadow: var(--shadow-hover);
  transform: translateY(-4px);
}

.testimonial-card .avatar {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--blue-primary), #93c5fd);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-weight: 700;
  margin-bottom: 16px;
}

.testimonial-card .name {
  font-weight: 700;
  color: var(--text-dark);
  margin-bottom: 4px;
}

.testimonial-card .role {
  font-size: 13px;
  color: var(--text-muted);
  margin-bottom: 12px;
}

.testimonial-card blockquote {
  font-size: 15px;
  color: var(--text-muted);
  line-height: 1.6;
  font-style: italic;
}

/* FAQ */
.faq-list {
  max-width: 720px;
  margin: 0 auto;
}

.faq-item {
  background: white;
  border-radius: var(--radius-sm);
  margin-bottom: 12px;
  box-shadow: 0 2px 12px rgba(0,0,0,0.04);
  overflow: hidden;
  transition: box-shadow 0.3s ease;
}

.faq-item:hover {
  box-shadow: var(--shadow);
}

.faq-question {
  width: 100%;
  padding: 20px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  text-align: left;
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-dark);
  background: none;
  border: none;
  cursor: pointer;
  transition: background 0.2s;
}

.faq-question:hover {
  background: var(--blue-bg);
}

.faq-question .arrow {
  flex-shrink: 0;
  margin-left: 16px;
  transition: transform 0.3s ease;
}

.faq-item.open .faq-question .arrow {
  transform: rotate(180deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s ease;
}

.faq-answer-inner {
  padding: 0 24px 20px;
  color: var(--text-muted);
  line-height: 1.7;
}

/* Scientific sources */
.sources-section {
  background: transparent;
  border-radius: var(--radius);
  padding: 48px;
}

.sources-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
  margin-top: 32px;
}

.source-card {
  background: white;
  border-radius: var(--radius-sm);
  padding: 20px;
  border-left: 4px solid var(--blue-primary);
  transition: transform 0.2s, box-shadow 0.2s;
}

.source-card:hover {
  transform: translateX(4px);
  box-shadow: var(--shadow);
}

.source-card a {
  color: var(--blue-primary);
  font-weight: 600;
  text-decoration: none;
}

.source-card a:hover {
  text-decoration: underline;
}

.source-card .meta {
  font-size: 13px;
  color: var(--text-muted);
  margin-top: 8px;
}

/* CTA final */
.cta-section {
  background: linear-gradient(135deg, var(--blue-bg) 0%, var(--blue-light) 100%);
  padding: 80px 24px;
  text-align: center;
  margin: 0 0 0;
  position: relative;
  overflow: hidden;
  width: 100%;
  max-width: none;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.cta-section::before {
  content: '';
  position: absolute;
  width: 300px;
  height: 300px;
  background: radial-gradient(circle, rgba(59, 130, 246, 0.2) 0%, transparent 70%);
  border-radius: 50%;
  top: -50%;
  right: -10%;
  animation: float 10s ease-in-out infinite;
}

.cta-section h2 {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  margin-bottom: 16px;
  color: var(--text-dark);
  position: relative;
  max-width: 640px;
}

.cta-section p {
  color: var(--text-muted);
  margin-bottom: 32px;
  position: relative;
  max-width: 560px;
}

.cta-section .btn {
  margin: 0 auto;
}

/* Footer */
.footer {
  background: var(--footer-bg);
  color: #94a3b8;
  padding: 60px 24px 24px;
}

.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr 2fr;
  gap: 48px;
  margin-bottom: 40px;
}

.footer-brand .logo {
  color: white;
  margin-bottom: 12px;
}

.footer-brand p {
  font-size: 14px;
  line-height: 1.6;
  margin-bottom: 16px;
  max-width: 260px;
}

.footer-links {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}

.footer-links h4 {
  color: white;
  font-size: 14px;
  margin-bottom: 16px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.footer-links a {
  color: #94a3b8;
  text-decoration: none;
  font-size: 14px;
  display: block;
  margin-bottom: 10px;
  transition: color 0.2s;
}

.footer-links a:hover {
  color: white;
}

.footer-bottom {
  max-width: 1200px;
  margin: 0 auto;
  padding-top: 24px;
  border-top: 1px solid rgba(255,255,255,0.1);
  font-size: 13px;
  text-align: center;
}

/* Legal pages */
.legal-page {
  max-width: 800px;
  margin: 0 auto;
  padding: 40px 24px 80px;
}

.legal-page h1 {
  font-size: 2rem;
  margin-bottom: 24px;
  color: var(--text-dark);
}

.legal-page h2 {
  font-size: 1.35rem;
  margin: 32px 0 16px;
  color: var(--text-dark);
}

.legal-page p, .legal-page li {
  color: var(--text-muted);
  line-height: 1.8;
  margin-bottom: 12px;
}

.legal-page ul {
  margin: 16px 0 16px 24px;
}

/* Responsive */
@media (max-width: 768px) {
  .nav { display: none; }
  .hero-cta { flex-direction: column; }
  .hero-cta input { min-width: 100%; }
  .feature-block {
    grid-template-columns: 1fr;
    direction: ltr;
    margin-bottom: 48px;
  }
  .feature-block:nth-child(even) { direction: ltr; }
  .footer-inner {
    grid-template-columns: 1fr;
    text-align: center;
  }
  .footer-brand p { max-width: none; }
  .footer-links { grid-template-columns: 1fr; text-align: center; }
}

/* Scroll animations */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Animación de entrada para secciones (scroll) */
.section-title {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease 0.2s, transform 0.6s ease 0.2s;
}

.reveal.visible .section-title {
  opacity: 1;
  transform: translateY(0);
}

/* Hover suave en tarjetas de fuentes */
.source-card {
  opacity: 1;
  transition: opacity 0.2s, transform 0.2s, box-shadow 0.2s;
}

.source-card:active {
  transform: translateX(2px);
}