/* ===========================
   ESTILOS BASE
   =========================== */
@import url('https://fonts.googleapis.com/css2?family=Space+Grotesk:wght@400;500;700&family=Inter:wght@400;600&display=swap');

:root {
  --color-texto: #f6f1eb;
  --color-primario: #0072ff;
  --color-secundario: #00d4ff;
  --color-fondo1: #0f0f0f;
  --color-fondo2: #1a1a1a;
  --color-fondo3: #111111;
  --color-fondo4: #181818;
  --sombra: rgba(0, 114, 255, 0.6);
}

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

body {
  font-family: "Inter", sans-serif;
  color: var(--color-texto);
  background-color: var(--color-fondo1);
  scroll-behavior: smooth;
  overflow-x: hidden;
}

/* ===========================
   LOGO PRINCIPAL
   =========================== */
.logo {
  width: clamp(120px, 10vw, 240px); /* Escalable */
  height: auto;
  display: block;
  margin: 0 auto 1.5rem auto;
  filter: drop-shadow(0 0 8px rgba(0, 212, 255, 0.3));
  transition: transform 0.3s ease, filter 0.3s ease;
}

.logo:hover {
  transform: scale(1.05);
  filter: drop-shadow(0 0 15px rgba(0, 212, 255, 0.6));
}

/* ===========================
   SECCIONES
   =========================== */
.seccion {
  height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
  padding: 2rem;
  padding-bottom: 8rem; /* espacio para el footer */
  transition: background 0.6s ease;
  box-sizing: border-box;
}

#inicio {
  background: linear-gradient(180deg, var(--color-fondo1) 0%, var(--color-fondo2) 100%);
}

#aprendizaje {
  background: linear-gradient(180deg, var(--color-fondo2) 0%, var(--color-fondo3) 100%);
}

#proximo {
  background: linear-gradient(180deg, var(--color-fondo3) 0%, var(--color-fondo4) 100%);
}

/* ===========================
   VIDEO EMBED
   =========================== */
.video-container {
  width: 80%;
  max-width: 720px;
  aspect-ratio: 16 / 9;
  margin: 2rem auto;
  box-shadow: 0 0 25px rgba(0, 212, 255, 0.15);
  border-radius: 12px;
  overflow: hidden;
  transition: transform 0.3s ease;
}

.video-container:hover {
  transform: scale(1.02);
}

iframe {
  width: 100%;
  height: 100%;
  border: none;
}

/* ===========================
   BOTONES
   =========================== */
.boton-proyecto {
  display: inline-block;
  padding: 1rem 2.4rem;
  margin-top: 1rem;
  background: linear-gradient(135deg, var(--color-secundario), var(--color-primario));
  color: #fff;
  text-decoration: none;
  border-radius: 50px;
  font-weight: 600;
  letter-spacing: 0.05em;
  box-shadow: 0 0 12px var(--sombra);
  transition: transform 0.3s, box-shadow 0.3s;
}

.boton-proyecto:hover {
  transform: scale(1.07);
  box-shadow: 0 0 22px var(--sombra);
}

/* ===========================
   FLECHAS DE SCROLL
   =========================== */
.scroll-down {
  margin-top: 2rem;
  font-size: 2rem;
  color: var(--color-secundario);
  cursor: pointer;
  animation: blink 1.5s infinite;
  text-shadow: 0 0 10px rgba(0, 212, 255, 0.6);
}

@keyframes blink {
  0%, 100% { opacity: 0.3; transform: translateY(0); }
  50% { opacity: 1; transform: translateY(8px); }
}

/* ===========================
   FLECHA FIJA (SUBIR ARRIBA)
   =========================== */
.flecha-arriba {
  position: fixed;
  bottom: 100px;
  right: 40px;
  background: linear-gradient(135deg, var(--color-secundario), var(--color-primario));
  color: #fff;
  border-radius: 50%;
  padding: 0.9rem 1.1rem;
  font-size: 1.5rem;
  cursor: pointer;
  box-shadow: 0 0 12px var(--sombra);
  transition: transform 0.3s, box-shadow 0.3s, opacity 0.3s;
  opacity: 0;
  pointer-events: none;
  z-index: 20;
}

.flecha-arriba.visible {
  opacity: 1;
  pointer-events: auto;
}

.flecha-arriba:hover {
  transform: scale(1.1);
  box-shadow: 0 0 24px var(--sombra);
}

/* ===========================
   FOOTER STICKY
   =========================== */
footer {
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100%;
  background: rgba(10, 10, 10, 0.95);
  backdrop-filter: blur(8px);
  color: #999;
  text-align: center;
  padding: 0.8rem 0;
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  z-index: 10;
}

footer .redes {
  margin-top: 0.3rem;
}

footer .redes a {
  color: var(--color-texto);
  margin: 0 0.6rem;
  font-size: 1.3rem;
  transition: color 0.3s, transform 0.3s, text-shadow 0.3s;
}

footer .redes a:hover {
  color: var(--color-secundario);
  transform: scale(1.15);
  text-shadow: 0 0 10px var(--sombra);
}

/* ===========================
   RESPONSIVE
   =========================== */
@media (max-width: 768px) {
  .logo {
    width: 160px;
  }

  .video-container {
    width: 90%;
  }

  .boton-proyecto {
    padding: 0.9rem 1.6rem;
    font-size: 0.95rem;
  }

  .flecha-arriba {
    right: 20px;
    bottom: 80px;
  }
}