/* ChattFlow — landing page pública. CSS a mano, sin frameworks ni paso de compilación. */
@import url('https://fonts.googleapis.com/css2?family=Plus+Jakarta+Sans:wght@400;500;600;700&display=swap');

:root {
  --color-primary: #2563EB;
  --color-primary-dark: #1D4ED8;
  --color-primary-light: #EFF6FF;
  --color-accent: #2962FF;
  --color-bg: #F8FAFC;
  --color-bg-alt: #F1F5F9;
  --color-text: #1E293B;
  --color-text-muted: #64748B;
  --color-border: #E2E8F0;
  --color-card: #FFFFFF;
  --color-ring: #2563EB;
  --radius: 16px;
  --max-width: 1120px;
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-primary: #3B82F6;
    --color-primary-dark: #2563EB;
    --color-primary-light: #1E3A8A;
    --color-accent: #2962FF;
    --color-bg: #0F172A;
    --color-bg-alt: #1E293B;
    --color-text: #F8FAFC;
    --color-text-muted: #94A3B8;
    --color-border: #334155;
    --color-card: #0F172A;
    --color-ring: #3B82F6;
    color-scheme: dark;
  }
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: "Plus Jakarta Sans", -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.55;
}

h1, h2, h3, h4, h5, h6 {
  text-wrap: balance;
}

:focus-visible {
  outline: 2px solid var(--color-ring);
  outline-offset: 2px;
}

:focus:not(:focus-visible) {
  outline: none;
}

@media (prefers-reduced-motion: reduce) {
  *, ::before, ::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

a {
  color: inherit;
}

img,
svg {
  display: block;
  max-width: 100%;
}

.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* ---------- Header ---------- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: color-mix(in srgb, var(--color-bg) 80%, transparent);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--color-border);
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.25rem;
  text-decoration: none;
  color: var(--color-text);
}

.brand-mark {
  width: 34px;
  height: 34px;
  border-radius: 10px;
  background: var(--color-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 28px;
}

.site-nav a:not(.btn) {
  text-decoration: none;
  color: var(--color-text-muted);
  font-size: 0.95rem;
  font-weight: 500;
}

.site-nav a:not(.btn):hover {
  color: var(--color-text);
}

.nav-cta {
  display: inline-flex;
}

/* ---------- Buttons ---------- */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 13px 24px;
  border-radius: 12px;
  font-weight: 600;
  font-size: 0.98rem;
  text-decoration: none;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform 0.15s ease, background 0.15s ease, box-shadow 0.15s ease;
}

.btn:hover {
  transform: translateY(-1px);
}

.btn-primary {
  background: var(--color-primary);
  color: #ffffff;
  box-shadow: 0 8px 20px -8px color-mix(in srgb, var(--color-primary) 70%, transparent);
}

.btn-primary:hover {
  background: var(--color-primary-dark);
}

.btn-accent {
  background: var(--color-accent);
  color: #ffffff;
  box-shadow: 0 8px 20px -8px color-mix(in srgb, var(--color-accent) 70%, transparent);
}

.btn-accent:hover {
  background: #1D4ED8;
}

.btn-outline {
  background: transparent;
  border-color: var(--color-border);
  color: var(--color-text);
}

.btn-outline:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.btn-lg {
  padding: 16px 30px;
  font-size: 1.05rem;
}

/* ---------- Hero ---------- */

.hero {
  padding: 88px 0 72px;
}

.hero .container {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 56px;
  align-items: center;
}

.eyebrow {
  display: inline-block;
  background: var(--color-primary-light);
  color: var(--color-primary-dark);
  font-weight: 600;
  font-size: 0.82rem;
  letter-spacing: 0.02em;
  padding: 6px 14px;
  border-radius: 999px;
  margin-bottom: 18px;
}

@media (prefers-color-scheme: dark) {
  .eyebrow {
    color: var(--color-primary);
  }
}

.hero h1 {
  font-size: clamp(2.1rem, 4vw, 3.1rem);
  line-height: 1.15;
  margin: 0 0 20px;
  letter-spacing: -0.01em;
}

.hero p.lead {
  font-size: 1.15rem;
  color: var(--color-text-muted);
  margin: 0 0 32px;
  max-width: 52ch;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-bottom: 20px;
}

.hero-note {
  font-size: 0.88rem;
  color: var(--color-text-muted);
}

.hero-visual {
  background: color-mix(in srgb, var(--color-bg-alt) 70%, transparent);
  backdrop-filter: blur(12px);
  border: 1px solid color-mix(in srgb, var(--color-border) 50%, transparent);
  border-radius: 24px;
  padding: 28px;
  box-shadow: 0 20px 40px -10px rgba(0, 0, 0, 0.05);
}

.phone-mock {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: 20px;
  padding: 18px;
  max-width: 320px;
  margin: 0 auto;
  box-shadow: 0 24px 48px -24px rgba(0, 0, 0, 0.25);
}

.phone-mock .bubble {
  border-radius: 14px;
  padding: 12px 14px;
  margin-bottom: 10px;
  font-size: 0.88rem;
  max-width: 82%;
}

.phone-mock .bubble.in {
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border);
}

.phone-mock .bubble.out {
  background: var(--color-primary);
  color: #fff;
  margin-left: auto;
}

/* ---------- Sections ---------- */

section {
  padding: 72px 0;
}

.section-alt {
  background: var(--color-bg-alt);
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
}

.section-head {
  max-width: 640px;
  margin: 0 auto 48px;
  text-align: center;
}

.section-head h2 {
  font-size: clamp(1.7rem, 3vw, 2.3rem);
  margin: 0 0 14px;
  letter-spacing: -0.01em;
}

.section-head p {
  color: var(--color-text-muted);
  font-size: 1.05rem;
  margin: 0;
}

/* ---------- Features ---------- */

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.feature-card {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 26px;
  box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.feature-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.05);
}

.feature-icon {
  width: 44px;
  height: 44px;
  border-radius: 12px;
  background: var(--color-primary-light);
  color: var(--color-primary-dark);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 16px;
}

@media (prefers-color-scheme: dark) {
  .feature-icon {
    color: var(--color-primary);
  }
}

.feature-card h3 {
  font-size: 1.08rem;
  margin: 0 0 8px;
}

.feature-card p {
  color: var(--color-text-muted);
  font-size: 0.95rem;
  margin: 0;
}

/* ---------- Steps ---------- */

.steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  counter-reset: step;
}

.step {
  position: relative;
  padding-top: 8px;
}

.step .step-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 999px;
  background: var(--color-primary);
  color: #fff;
  font-weight: 700;
  font-size: 0.95rem;
  margin-bottom: 14px;
}

.step h3 {
  margin: 0 0 8px;
  font-size: 1.02rem;
}

.step p {
  margin: 0;
  color: var(--color-text-muted);
  font-size: 0.92rem;
}

/* ---------- Pricing ---------- */

.pricing-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
  max-width: 760px;
  margin: 0 auto;
}

.price-card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 32px 28px;
}

.price-card.featured {
  border-color: var(--color-primary);
  box-shadow: 0 16px 40px -20px color-mix(in srgb, var(--color-primary) 60%, transparent);
}

.price-card h3 {
  margin: 0 0 4px;
  font-size: 1.15rem;
}

.price-tag {
  font-size: 1.6rem;
  font-weight: 700;
  margin: 10px 0 18px;
  color: var(--color-text-muted);
}

.price-card ul {
  list-style: none;
  padding: 0;
  margin: 0 0 24px;
  display: grid;
  gap: 10px;
  font-size: 0.94rem;
}

.price-card li {
  display: flex;
  gap: 8px;
  color: var(--color-text-muted);
}

.price-card li::before {
  content: "✓";
  color: var(--color-primary);
  font-weight: 700;
}

/* ---------- CTA final ---------- */

.cta-final {
  text-align: center;
}

.cta-final h2 {
  font-size: clamp(1.7rem, 3vw, 2.2rem);
  margin: 0 0 14px;
}

.cta-final p {
  color: var(--color-text-muted);
  margin: 0 0 28px;
}

/* ---------- Footer ---------- */

.site-footer {
  border-top: 1px solid var(--color-border);
  padding: 40px 0;
}

.site-footer .container {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  align-items: center;
  justify-content: space-between;
}

.footer-links {
  display: flex;
  gap: 20px;
  flex-wrap: wrap;
}

.footer-links a {
  text-decoration: none;
  color: var(--color-text-muted);
  font-size: 0.9rem;
}

.footer-links a:hover {
  color: var(--color-primary);
}

.footer-note {
  color: var(--color-text-muted);
  font-size: 0.85rem;
}

/* ---------- Nav toggle (móvil) ---------- */

.nav-toggle {
  display: none;
  background: none;
  border: 1px solid var(--color-border);
  border-radius: 10px;
  padding: 8px 10px;
  cursor: pointer;
}

/* ---------- Legal page ---------- */

.legal {
  padding: 56px 0 96px;
}

.legal .container {
  max-width: 760px;
}

.legal h1 {
  font-size: 2rem;
  margin-bottom: 6px;
}

.legal .updated {
  color: var(--color-text-muted);
  font-size: 0.9rem;
  margin-bottom: 36px;
}

.legal h2 {
  font-size: 1.2rem;
  margin: 36px 0 10px;
}

.legal p,
.legal li {
  color: var(--color-text-muted);
  font-size: 0.98rem;
}

.legal .callout {
  background: var(--color-primary-light);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 18px 20px;
  margin-bottom: 32px;
  font-size: 0.92rem;
}

.legal .callout strong {
  color: var(--color-primary-dark);
}

@media (prefers-color-scheme: dark) {
  .legal .callout strong {
    color: var(--color-primary);
  }
}

/* ---------- Responsive ---------- */

@media (max-width: 900px) {
  .hero .container {
    grid-template-columns: 1fr;
  }

  .hero-visual {
    order: -1;
  }

  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .steps {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 640px) {
  .site-nav {
    position: fixed;
    inset: 72px 16px auto 16px;
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    padding: 16px;
    flex-direction: column;
    align-items: stretch;
    gap: 14px;
    box-shadow: 0 16px 40px -16px rgba(0, 0, 0, 0.3);
    display: none;
  }

  .site-nav.open {
    display: flex;
  }

  .nav-toggle {
    display: inline-flex;
  }

  .nav-cta .btn {
    width: 100%;
  }

  .features-grid,
  .steps,
  .pricing-grid {
    grid-template-columns: 1fr;
  }

  .hero {
    padding: 56px 0 48px;
  }

  section {
    padding: 56px 0;
  }
}