/* ------------------------------------------------------------------
   style.css – Paleta “Azules Espaciales” + estilos de portada
   ------------------------------------------------------------------ */

/* 1. Variables globales – paleta completa (resumen) */
:root {
  --color-background: #0A0F1C;
  --color-surface:    #121E33;
  --color-text:       #E6F8FF;
  --color-text-secondary: #A7C6E9;
  --color-primary:    #009EFF; /* azul eléctrico */
  --color-primary-hover:  #00C8FF;
  --color-primary-active: #00E4FF; /* turquesa neón */
  --color-secondary: rgba(0, 98, 255, 0.12);
  --color-secondary-hover: rgba(0, 132, 255, 0.20);
  --color-secondary-active: rgba(0, 132, 255, 0.25);
  --color-border: rgba(0, 132, 255, 0.20);
  --color-focus-ring: rgba(0, 132, 255, 0.40);
  --gradient-bg: linear-gradient(135deg,
                  #050B19 0%,
                  #002868 25%,
                  #004FAF 50%,
                  #0084F4 75%,
                  #00E4FF 100%);
  --shadow-card: 0 10px 25px rgba(0, 228, 255, 0.12);
  --shadow-hover: 0 20px 40px rgba(0, 228, 255, 0.35);
  --transition-smooth: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* 2. Modo oscuro automático (mantiene la coherencia cromática) */
@media (prefers-color-scheme: dark) {
  :root {
    --color-background: #050B19;
    --color-surface:    #0E1526;
    --color-text:       #DAF0FF;
    --color-text-secondary: #8FB1D6;
  }
}

/* 3. Reset mínimo + tipografía base */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}
html {
  font-size: 14px;
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI',
               Roboto, sans-serif;
  line-height: 1.5;
  color: var(--color-text);
  background-color: var(--color-background);
  -webkit-font-smoothing: antialiased;
}
body {
  min-height: 100vh;
  overflow-x: hidden;
  background: var(--gradient-bg);
  position: relative;
}

/* 4. Canvas de partículas decorativas */
#particles-canvas {
  position: fixed;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 0;
}

/* 5. Contenedor genérico */
.container {
  width: 100%;
  max-width: 1200px;
  margin-inline: auto;
  padding-inline: 20px;
  position: relative;
  z-index: 2;
}

/* 6. Encabezado */
.header {
  padding: 60px 0 40px;
  text-align: center;
}
.header__title {
  font-family: 'Noxlock', sans-serif;
  font-size: 3.5rem;
  font-weight: 400;
  letter-spacing: 2px;
  background: linear-gradient(135deg,
              var(--color-primary),
              var(--color-primary-hover),
              var(--color-primary-active));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  text-shadow: 0 0 30px rgba(0, 228, 255, 0.30);
  margin-bottom: 10px;
}
.header__subtitle {
  font-size: 1.2rem;
  color: rgba(255, 255, 255, 0.8);
  font-weight: 300;
  letter-spacing: 1px;
}

/* 7. Guía de uso */
.guia-uso {
  margin-top: 35px;
  max-width: 720px;
  margin-inline: auto;
  background: rgba(255, 255, 255, 0.05);
  backdrop-filter: blur(10px);
  border: 1px solid var(--color-border);
  border-radius: 12px;
  padding: 25px 30px;
  text-align: left;
}
.guia-uso__lista {
  counter-reset: pasos;
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.guia-uso__lista li {
  list-style: none;
  position: relative;
  padding-left: 42px;
  font-size: 0.95rem;
}
.guia-uso__lista li::before {
  counter-increment: pasos;
  content: counter(pasos);
  position: absolute;
  left: 0;
  top: 0;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: var(--color-primary);
  color: #fff;
  font-weight: 600;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* 8. Grid de aplicaciones */
.main {
  padding: 40px 0 80px;
}
.applications-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 30px;
}

/* 9. Tarjeta de aplicación (animaciones incluidas) */
@keyframes fadeInUp {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.app-card {
  --delay: 0s;
  background: rgba(255, 255, 255, 0.05);
  backdrop-filter: blur(20px);
  border: 1px solid var(--color-border);
  border-radius: 12px;
  padding: 30px;
  text-align: center;
  cursor: pointer;
  transition: var(--transition-smooth);
  overflow: hidden;
  box-shadow: var(--shadow-card);
  position: relative;
  opacity: 0;
  transform: translateY(30px);
  animation: fadeInUp 0.6s ease forwards;
}
.app-card:nth-child(1) { animation-delay: 0.1s; }
.app-card:nth-child(2) { animation-delay: 0.2s; }
.app-card:nth-child(3) { animation-delay: 0.3s; }
.app-card:nth-child(4) { animation-delay: 0.4s; }

.app-card::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg,
              rgba(0, 228, 255, 0.10),
              rgba(0, 148, 255, 0.10));
  opacity: 0;
  transition: opacity 0.3s ease;
  z-index: -1;
}

.app-card:hover {
  transform: translateY(-10px);
  box-shadow: var(--shadow-hover);
  border-color: rgba(0, 228, 255, 0.50);
}
.app-card:hover::before { opacity: 1; }

.app-card__icon {
  font-size: 60px;
  line-height: 1;
  margin-bottom: 20px;
  color: var(--color-primary);
  transition: var(--transition-smooth);
}
.app-card:hover .app-card__icon {
  color: var(--color-primary-hover);
  transform: scale(1.1);
}

.app-card__title {
  font-size: 1.4rem;
  font-weight: 600;
  margin-bottom: 12px;
  color: #ffffff;
  transition: color 0.3s ease;
}
.app-card:hover .app-card__title { color: var(--color-primary); }

.app-card__description {
  font-size: 0.95rem;
  color: rgba(255, 255, 255, 0.70);
  line-height: 1.5;
  transition: color 0.3s ease;
}
.app-card:hover .app-card__description {
  color: rgba(255, 255, 255, 0.90);
}

/* Efecto radial al hacer hover */
.app-card__hover-effect {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 0;
  height: 0;
  background: radial-gradient(circle,
              rgba(0, 228, 255, 0.30),
              transparent 70%);
  border-radius: 50%;
  transform: translate(-50%, -50%);
  pointer-events: none;
  transition: var(--transition-smooth);
}
.app-card:hover .app-card__hover-effect {
  width: 200px;
  height: 200px;
}

/* 10. Utilidades de accesibilidad */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

/* 11. Media-queries responsivas */
@media (max-width: 1024px) {
  .applications-grid { gap: 25px; }
  .header__title { font-size: 3rem; }
}
@media (max-width: 768px) {
  .applications-grid { grid-template-columns: repeat(2, 1fr); gap: 20px; }
  .app-card { padding: 25px; }
  .header__title { font-size: 2.5rem; }
}
@media (max-width: 576px) {
  .applications-grid { grid-template-columns: 1fr; gap: 20px; }
  .app-card { padding: 20px; }
  .header__title {
    font-size: 2rem;
    letter-spacing: 1px;
  }
  .header__subtitle { font-size: 1rem; }
}
/* ========================================
   BOTÓN VOLVER - ESTILO XADE
======================================== */
/* Botón “Volver” con fondo cian redondeado */
.boton-volver {
  position: absolute;
  top: 20px;          /* ajusta según tu diseño */
  left: 20px;
  z-index: 3;

  /* Estilo visual */
  background: cyan;     /* cian de la paleta */ /* [1] */
  color: #11b51c;                      /* buen contraste sobre cian */
  border: none;
  border-radius: 9999px;               /* forma de píldora */
  padding: 6px 18px;                   /* algo más de aire */
  font-weight: 600;
  opacity: 0.85;                       /* discreto */

  transition: opacity 0.3s var(--transition-smooth),
              transform 0.3s var(--transition-smooth);
}

.boton-volver:hover,
.boton-volver:focus-visible {
  opacity: 1;
  transform: translateY(-2px);
}