/* --- Reset y base --- */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --azul-premium: #0A1F44;        /* Azul oscuro premium */
  --azul-acento: #1E3A6F;         /* Variante más clara para hover */
  --azul-suave: #E6F0FF;
  --blanco: #FFFFFF;
  --gris-fondo: #F8FAFC;          /* Fondo gris muy claro para secciones alternas */
  --borde: #E9EEF5;
  --texto-oscuro: #1E293B;
  --texto-suave: #475569;
  --sombra-suave: 0 20px 35px -8px rgba(0, 0, 0, 0.05), 0 10px 15px -6px rgba(0, 0, 0, 0.02);
  --borde-radio: 24px;

  /* Colores de la app (tema oscuro de la pantalla de lectura) */
  --app-fondo: #0F0F0F;
  --app-superficie: #161616;
  --app-linea: #262626;
  --app-texto: #EDEDEB;
  --app-texto-suave: #A3A3A0;
  --app-texto-tenue: #6B6B68;
  --app-acento: #A9BBD3;
  --app-bloque: #202020;          /* recuadro de las expresiones */
  --app-borde-bloque: #2C2C2C;
  --app-formula-fondo: #1A1A1A;
  --app-formula-borde: #3B3B3B;
  --app-serif: Georgia, 'Noto Serif', 'Times New Roman', serif;
}

html {
  scroll-padding-top: 84px;       /* las secciones no quedan debajo de la barra fija */
}

body {
  font-family: 'Inter', sans-serif;
  background-color: var(--blanco);
  color: var(--texto-oscuro);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4, .btn-primary, .btn-secondary, .btn-outline, .btn-light, .logo-text, .nav-links a {
  font-family: 'Playfair Display', serif;
  font-weight: 600;
  letter-spacing: -0.02em;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* --- Barra de navegación --- */
.navbar {
  background-color: var(--blanco);
  padding: 16px 0;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 1px 0 rgba(0, 0, 0, 0.06), 0 4px 20px rgba(10, 31, 68, 0.04);
  border-bottom: 1px solid #EEF2F7;
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.logo {
  display: flex;
  align-items: center;
  color: var(--azul-premium);
  text-decoration: none;
}

.logo-text {
  font-size: 28px;
  font-weight: 700;
  letter-spacing: -0.03em;
  color: var(--azul-premium);
}

.nav-links {
  display: flex;
  list-style: none;
  gap: 32px;
}

.nav-links a {
  text-decoration: none;
  color: var(--texto-oscuro);
  font-size: 16px;
  font-weight: 500;
  transition: color 0.2s;
}

.nav-links a:hover {
  color: var(--azul-premium);
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 22px;
  color: var(--azul-premium);
  cursor: pointer;
  padding: 6px;
}

.btn-outline {
  display: inline-block;
  padding: 10px 22px;
  border-radius: 40px;
  border: 1.5px solid var(--azul-premium);
  color: var(--azul-premium);
  text-decoration: none;
  font-size: 16px;
  transition: all 0.2s;
}

.btn-outline:hover {
  background-color: var(--azul-premium);
  color: white;
}

/* --- Hero --- */
.hero {
  background-color: var(--blanco);
  padding: 70px 0 90px;
}

.hero-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: stretch;
  gap: 50px;
  flex-wrap: wrap;
}

.hero-content {
  flex: 1 1 450px;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.hero-title {
  font-size: 58px;
  line-height: 1.1;
  font-weight: 700;
  color: var(--texto-oscuro);
  margin-bottom: 20px;
}

.highlight {
  color: var(--azul-premium);
  white-space: nowrap;
}

.hero-subtitle {
  font-size: 18px;
  color: var(--texto-suave);
  margin-bottom: 32px;
  max-width: 550px;
}

.hero-actions {
  display: flex;
  gap: 16px;
  margin-bottom: 32px;
  flex-wrap: wrap;
}

.hero-puntos {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 10px 28px;
  color: var(--texto-suave);
  font-size: 15px;
}

.hero-puntos i {
  color: var(--azul-premium);
  margin-right: 6px;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  background-color: var(--azul-premium);
  color: white;
  padding: 14px 34px;
  border-radius: 60px;
  text-decoration: none;
  font-size: 18px;
  border: none;
  cursor: pointer;
  transition: background 0.2s;
  box-shadow: 0 12px 25px -8px rgba(10, 31, 68, 0.3);
}

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

.btn-secondary {
  display: inline-block;
  background-color: transparent;
  color: var(--azul-premium);
  padding: 14px 34px;
  border-radius: 60px;
  text-decoration: none;
  font-size: 18px;
  border: 1.5px solid var(--azul-premium);
  transition: all 0.2s;
}

.btn-secondary:hover {
  background-color: var(--azul-premium);
  color: white;
}

.hero-images {
  flex: 1 1 420px;
  display: flex;
  min-height: 460px;
}

.hero-img-stack {
  flex: 1;
  display: flex;
}

.hero-img-secondary {
  width: 100%;
  object-fit: cover;
  border-radius: var(--borde-radio);
  box-shadow: var(--sombra-suave);
}

/* --- Secciones genéricas --- */
.section {
  padding: 90px 0;
}

.bg-white {
  background-color: var(--blanco);
}

.bg-light {
  background-color: var(--gris-fondo);
}

.section-header {
  text-align: center;
  max-width: 720px;
  margin: 0 auto 56px;
}

.section-kicker {
  display: inline-block;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--azul-premium);
  background: var(--azul-suave);
  padding: 6px 14px;
  border-radius: 40px;
  margin-bottom: 18px;
}

.section-title {
  font-size: 44px;
  font-weight: 700;
  color: var(--texto-oscuro);
  margin-bottom: 16px;
  line-height: 1.15;
}

.section-subtitle {
  font-size: 18px;
  color: var(--texto-suave);
}

/* --- La app: características --- */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: 28px;
}

.feature-card {
  background: white;
  padding: 36px 26px;
  border-radius: var(--borde-radio);
  box-shadow: var(--sombra-suave);
  border: 1px solid var(--borde);
  transition: transform 0.2s;
}

.feature-card:hover {
  transform: translateY(-6px);
}

.feature-card i {
  font-size: 30px;
  color: var(--azul-premium);
  margin-bottom: 18px;
}

.feature-card h3 {
  font-size: 22px;
  margin-bottom: 10px;
}

.feature-card p {
  color: var(--texto-suave);
  font-size: 15px;
}

/* --- Materias --- */
.materias-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 24px;
}

.materia-card {
  background: white;
  padding: 30px 26px;
  border-radius: var(--borde-radio);
  border: 1px solid var(--borde);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.02);
  transition: border-color 0.2s, transform 0.2s;
}

.materia-card:hover {
  border-color: var(--azul-premium);
  transform: translateY(-4px);
}

.materia-card i {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  border-radius: 14px;
  background: var(--azul-suave);
  color: var(--azul-premium);
  font-size: 20px;
  margin-bottom: 16px;
}

.materia-card h3 {
  font-size: 22px;
  margin-bottom: 8px;
}

.materia-card p {
  color: var(--texto-suave);
  font-size: 15px;
}

/* --- Así se ve: teléfono + guía --- */
.demo {
  display: flex;
  align-items: flex-start;
  justify-content: center;
  gap: 64px;
  flex-wrap: wrap;
}

.telefono {
  width: 360px;
  max-width: 100%;
  background: #050505;
  border-radius: 44px;
  padding: 12px;
  box-shadow: 0 40px 70px -20px rgba(10, 31, 68, 0.45), 0 0 0 1px #1c1c1c inset;
  flex-shrink: 0;
}

.telefono-barra {
  display: flex;
  justify-content: space-between;
  padding: 6px 22px 8px;
  font-size: 12px;
  color: var(--app-texto);
  background: var(--app-fondo);
  border-radius: 32px 32px 0 0;
  font-weight: 500;
}

.telefono-barra i {
  font-size: 11px;
  margin-left: 4px;
}

.app {
  background: var(--app-fondo);
  border-radius: 0 0 32px 32px;
  height: 720px;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.app-cabecera {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 10px 16px 14px;
  border-bottom: 1px solid var(--app-linea);
  color: var(--app-texto-suave);
}

.app-titulo {
  font-family: 'Cormorant Garamond', serif;
  font-weight: 300;
  font-size: 22px;
  line-height: 1.15;
  color: var(--app-texto);
}

.app-etiqueta {
  font-family: 'Inter', sans-serif;
  font-weight: 500;
  font-size: 10.5px;
  letter-spacing: 2.2px;
  text-transform: uppercase;
  color: var(--app-texto-suave);
}

.app-etiqueta.tenue {
  color: var(--app-texto-tenue);
}

.app-cuerpo {
  flex: 1;
  overflow-y: auto;
  padding: 8px 0 28px;
  scrollbar-width: thin;
  scrollbar-color: #2a2a2a transparent;
}

.app-h4 {
  font-family: var(--app-serif);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 1.4px;
  text-transform: uppercase;
  color: var(--app-texto);
  padding: 18px 12px 6px;
}

.app-fila {
  display: flex;
  gap: 8px;
  padding: 8px 12px 8px 10px;
}

.app-num {
  width: 24px;
  flex-shrink: 0;
  text-align: right;
  font-family: 'Inter', sans-serif;
  font-weight: 300;
  font-size: 11px;
  color: var(--app-texto-tenue);
  padding-top: 7px;
  font-variant-numeric: tabular-nums;
}

.app-fila > div,
.app-fila > p {
  flex: 1;
  min-width: 0;
}

.app-texto {
  font-family: var(--app-serif);
  font-size: 18px;
  line-height: 30px;
  color: var(--app-texto);
}

.app-texto strong {
  font-weight: 700;
}

.app-texto-ej {
  font-family: var(--app-serif);
  font-size: 16px;
  line-height: 26px;
  color: var(--app-texto);
  margin-top: 8px;
}

/* Expresión dentro del texto: recuadro tenue, como en la app */
.ex {
  display: inline-block;
  font-family: var(--app-serif);
  background: var(--app-bloque);
  border: 1px solid var(--app-borde-bloque);
  border-radius: 5px;
  padding: 0 6px;
  line-height: 24px;
  white-space: nowrap;
}

.lim {
  display: inline-flex;
  flex-direction: column;
  align-items: center;
  line-height: 1;
  vertical-align: middle;
}

.lim small {
  font-size: 0.62em;
  margin-top: 2px;
}

.frac {
  display: inline-flex;
  flex-direction: column;
  align-items: center;
  vertical-align: middle;
  line-height: 1.1;
  margin: 0 2px;
}

.frac > span:first-child {
  border-bottom: 1px solid currentColor;
  padding: 0 3px;
}

.frac > span:last-child {
  padding: 0 3px;
}

.app-formula {
  background: var(--app-formula-fondo);
  border: 1px solid var(--app-formula-borde);
  border-radius: 8px;
  padding: 12px;
}

.app-formula-ex {
  font-family: var(--app-serif);
  font-size: 19px;
  line-height: 30px;
  text-align: center;
  color: var(--app-texto);
  margin-top: 4px;
}

.app-aparte {
  border-left: 2px solid var(--app-linea);
  padding-left: 12px;
}

.app-proc {
  margin-top: 14px;
  background: var(--app-bloque);
  border: 1px solid var(--app-borde-bloque);
  border-radius: 8px;
  padding: 10px 8px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.app-renglon {
  display: flex;
  flex-direction: column;
  gap: 2px;
  align-items: center;
}

.app-renglon .rot {
  align-self: flex-start;
  font-family: 'Inter', sans-serif;
  font-size: 11.5px;
  letter-spacing: 0.3px;
  color: var(--app-texto-tenue);
}

.app-renglon .exp {
  font-family: var(--app-serif);
  font-size: 15px;
  color: var(--app-texto);
  white-space: nowrap;
}

.app-renglon.final {
  border-top: 2px solid var(--app-borde-bloque);
  padding-top: 8px;
}

.app-renglon.final .rot {
  color: var(--app-acento);
}

.app-renglon.final .exp {
  font-weight: 700;
}

.app-ejercicios {
  margin-top: 28px;
  border-top: 1px solid var(--app-linea);
}

.app-respuesta {
  font-family: var(--app-serif);
  font-size: 15px;
  line-height: 24px;
  color: var(--app-texto-suave);
  margin-top: 2px;
}

.demo-guia {
  list-style: none;
  counter-reset: guia;
  flex: 1 1 340px;
  max-width: 460px;
  display: flex;
  flex-direction: column;
  gap: 26px;
  padding-top: 24px;
}

.demo-guia li {
  counter-increment: guia;
  position: relative;
  padding-left: 60px;
}

.demo-guia li::before {
  content: counter(guia);
  position: absolute;
  left: 0;
  top: 0;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--azul-premium);
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: 'Playfair Display', serif;
  font-weight: 700;
  font-size: 17px;
}

.demo-guia h3 {
  font-size: 21px;
  margin-bottom: 4px;
}

.demo-guia p {
  color: var(--texto-suave);
  font-size: 15.5px;
}

/* --- Cómo funciona --- */
.pasos-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 28px;
}

.paso {
  text-align: center;
  padding: 34px 26px;
  border-radius: var(--borde-radio);
  border: 1px solid var(--borde);
  background: white;
}

.paso-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 52px;
  height: 52px;
  border-radius: 50%;
  border: 1.5px solid var(--azul-premium);
  color: var(--azul-premium);
  font-family: 'Playfair Display', serif;
  font-weight: 700;
  font-size: 22px;
  margin-bottom: 16px;
}

.paso h3 {
  font-size: 22px;
  margin-bottom: 8px;
}

.paso p {
  color: var(--texto-suave);
  font-size: 15px;
}

/* --- Botones de descarga --- */
.cta-buttons {
  display: flex;
  gap: 20px;
  justify-content: center;
  flex-wrap: wrap;
}

.btn-light {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  background: rgba(255, 255, 255, 0.12);
  color: white;
  padding: 16px 36px;
  border-radius: 60px;
  text-decoration: none;
  font-size: 18px;
  border: 1px solid rgba(255, 255, 255, 0.2);
  transition: background 0.2s;
}

.btn-light:hover {
  background: rgba(255, 255, 255, 0.2);
}

/* --- Footer --- */
.footer {
  background-color: #0B1A30;
  color: #94A3B8;
  padding: 40px 0;
}

.footer-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 20px;
}

.footer-logo {
  font-family: 'Playfair Display', serif;
  font-size: 22px;
  font-weight: 600;
  color: white;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 28px;
}

.footer-links a {
  color: #94A3B8;
  text-decoration: none;
  font-size: 15px;
  transition: color 0.2s;
}

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

/* --- Responsive --- */
@media (max-width: 900px) {
  .nav-toggle {
    display: block;
    margin-left: auto;
  }
  .nav-cta {
    display: none;
  }
  .nav-links {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    gap: 0;
    background: white;
    border-bottom: 1px solid #EEF2F7;
    box-shadow: 0 12px 24px rgba(10, 31, 68, 0.08);
  }
  .nav-links.abierto {
    display: flex;
  }
  .nav-links a {
    display: block;
    padding: 14px 24px;
  }
  .hero-title {
    font-size: 44px;
  }
  .hero-images {
    min-height: 340px;
  }
  .section-title {
    font-size: 36px;
  }
  .demo {
    gap: 40px;
  }
  .demo-guia {
    padding-top: 0;
  }
}

@media (max-width: 600px) {
  .container,
  .nav-container,
  .hero-container {
    padding: 0 16px;
  }
  .section {
    padding: 64px 0;
  }
  .hero {
    padding: 48px 0 64px;
  }
  .hero-title {
    font-size: 36px;
  }
  .hero-actions {
    flex-direction: column;
    align-items: stretch;
  }
  .hero-actions a {
    justify-content: center;
    text-align: center;
  }
  .hero-images {
    min-height: 240px;
  }
  .section-title {
    font-size: 30px;
  }
  .telefono {
    border-radius: 36px;
    padding: 8px;
  }
  .app {
    height: 620px;
  }
  .footer-content {
    flex-direction: column;
    text-align: center;
  }
  .footer-links {
    justify-content: center;
  }
}

/* ================= Página legal (privacidad) ================= */
.legal-hero {
  background-color: var(--blanco);
  padding: 80px 0 40px;
  text-align: center;
  border-bottom: 1px solid #EEF2F7;
}

.legal-hero h1 {
  font-size: 52px;
  font-weight: 700;
  color: var(--texto-oscuro);
  margin-bottom: 16px;
  line-height: 1.15;
}

.legal-hero p {
  font-size: 18px;
  color: var(--texto-suave);
  max-width: 640px;
  margin: 0 auto;
}

.legal-meta {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-top: 24px;
  padding: 8px 18px;
  background: var(--azul-suave);
  color: var(--azul-premium);
  border-radius: 40px;
  font-size: 14px;
  font-weight: 500;
}

.legal-body {
  padding: 70px 0 90px;
  background-color: var(--blanco);
}

.legal-container {
  max-width: 820px;
  margin: 0 auto;
  padding: 0 24px;
}

.legal-toc {
  background: var(--gris-fondo);
  border: 1px solid var(--borde);
  border-radius: var(--borde-radio);
  padding: 32px 36px;
  margin-bottom: 56px;
}

.legal-toc h2 {
  font-size: 22px;
  margin-bottom: 18px;
  color: var(--azul-premium);
}

.legal-toc ol {
  list-style: none;
  counter-reset: item;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px 24px;
}

.legal-toc ol li {
  counter-increment: item;
  font-size: 15px;
}

.legal-toc ol li a {
  color: var(--texto-oscuro);
  text-decoration: none;
  display: inline-flex;
  align-items: baseline;
  gap: 10px;
  transition: color 0.2s;
}

.legal-toc ol li a::before {
  content: counter(item, decimal-leading-zero);
  font-family: 'Playfair Display', serif;
  font-weight: 700;
  color: var(--azul-premium);
  font-size: 15px;
}

.legal-toc ol li a:hover {
  color: var(--azul-premium);
}

.legal-section {
  margin-bottom: 48px;
  scroll-margin-top: 100px;
}

.legal-section h2 {
  font-size: 30px;
  color: var(--texto-oscuro);
  margin-bottom: 18px;
  padding-bottom: 12px;
  border-bottom: 2px solid #EEF2F7;
  display: flex;
  align-items: center;
  gap: 12px;
}

.legal-section h2 .num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  flex-shrink: 0;
  background: var(--azul-premium);
  color: white;
  border-radius: 50%;
  font-size: 16px;
  font-weight: 700;
}

.legal-section h3 {
  font-size: 20px;
  color: var(--azul-premium);
  margin: 28px 0 12px;
}

.legal-section p {
  font-size: 16.5px;
  color: var(--texto-oscuro);
  margin-bottom: 16px;
  line-height: 1.7;
}

.legal-section ul {
  list-style: none;
  margin: 16px 0 20px;
  padding-left: 4px;
}

.legal-section ul li {
  position: relative;
  padding-left: 28px;
  margin-bottom: 10px;
  font-size: 16px;
  color: var(--texto-oscuro);
  line-height: 1.6;
}

.legal-section ul li::before {
  content: "•";
  color: var(--azul-premium);
  font-size: 22px;
  position: absolute;
  left: 6px;
  top: -3px;
  font-weight: 700;
}

.legal-callout {
  background: var(--azul-suave);
  border-left: 4px solid var(--azul-premium);
  border-radius: 12px;
  padding: 20px 26px;
  margin: 24px 0;
  font-size: 16px;
  color: var(--texto-oscuro);
  line-height: 1.6;
}

.legal-callout strong {
  color: var(--azul-premium);
}

.legal-section a {
  color: var(--azul-premium);
  text-decoration: underline;
  text-underline-offset: 3px;
  font-weight: 500;
  overflow-wrap: anywhere;
}

.legal-section a:hover {
  color: var(--azul-acento);
}

.legal-table-wrap {
  overflow-x: auto;
  margin: 24px 0;
  border-radius: 16px;
  border: 1px solid var(--borde);
}

.legal-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 15px;
}

.legal-table thead {
  background: var(--azul-premium);
  color: white;
}

.legal-table th,
.legal-table td {
  padding: 14px 18px;
  text-align: left;
  vertical-align: top;
}

.legal-table tbody tr:nth-child(even) {
  background: #F8FAFC;
}

.legal-table tbody tr {
  border-bottom: 1px solid #EEF2F7;
}

/* Recuadro azul de descarga (inicio y privacidad) */
.legal-cta {
  background: var(--azul-premium);
  border-radius: var(--borde-radio);
  padding: 48px 40px;
  text-align: center;
  color: white;
}

.legal-cta h3 {
  font-size: 30px;
  margin-bottom: 12px;
  color: white;
}

.legal-cta p {
  color: #CBD5E1;
  font-size: 16px;
  margin-bottom: 24px;
}

@media (max-width: 600px) {
  .legal-hero {
    padding: 56px 0 30px;
  }
  .legal-hero h1 {
    font-size: 36px;
  }
  .legal-container {
    padding: 0 16px;
  }
  .legal-toc {
    padding: 24px;
  }
  .legal-toc ol {
    grid-template-columns: 1fr;
  }
  .legal-section h2 {
    font-size: 24px;
  }
  .legal-cta {
    padding: 32px 24px;
  }
  .legal-cta h3 {
    font-size: 22px;
  }
}