/* ===== VARIABLES CSS ===== */
:root {
  --primary: #4142f5;
  --primary-dark: #2829c8;
  --accent: #c1fa3b;
  --bg-light: #ffffff;
  --bg-gradient: linear-gradient(
    135deg,
    #fff 0%,
    rgba(193, 250, 59, 0.15) 100%
  );
  --text-dark: #1a1a1a;
  --text-light: #666;
  --shadow-sm: 0 2px 12px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.12);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.16);
  --radius-sm: 12px;
  --radius-md: 20px;
  --radius-lg: 30px;
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: "Poppins", "Segoe UI", system-ui, -apple-system, sans-serif;
  background: var(--bg-gradient);
  color: var(--text-dark);
  line-height: 1.6;
  overflow-x: hidden;
  position: relative;
}

/* ===== DECORACIÓN DE FONDO ===== */
.bg-decoration {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: -1;
  opacity: 0.05;
  background-image: radial-gradient(
      circle at 20% 50%,
      var(--primary) 0%,
      transparent 50%
    ),
    radial-gradient(circle at 80% 80%, var(--accent) 0%, transparent 50%);
  pointer-events: none;
}

/* ===== HEADER ===== */
header {
  background: linear-gradient(
    135deg,
    var(--primary) 0%,
    var(--primary-dark) 100%
  );
  color: #fff;
  text-align: center;
  padding: 4rem 2rem 5rem;
  position: relative;
  overflow: hidden;
}

header::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: repeating-linear-gradient(
    45deg,
    transparent,
    transparent 10px,
    rgba(255, 255, 255, 0.03) 10px,
    rgba(255, 255, 255, 0.03) 20px
  );
}

.header-content {
  position: relative;
  z-index: 1;
  max-width: 800px;
  margin: 0 auto;
}

.logo-main {
  width: 120px;
  height: 120px;
  border-radius: 50%;
  margin: 0 auto 1.5rem;
  border: 5px solid rgba(255, 255, 255, 0.3);
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.3);
  animation: float 3s ease-in-out infinite;
}

@keyframes float {
  0%,
  100% {
    transform: translateY(0px);
  }
  50% {
    transform: translateY(-10px);
  }
}

header h1 {
  font-size: clamp(2.5rem, 6vw, 4rem);
  font-weight: 800;
  margin-bottom: 0.8rem;
  letter-spacing: -0.02em;
  animation: fadeInUp 0.6s ease-out;
}

header p {
  font-size: clamp(1rem, 2.5vw, 1.3rem);
  opacity: 0.95;
  font-weight: 300;
  animation: fadeInUp 0.6s ease-out 0.2s backwards;
}

.header-wave {
  position: absolute;
  bottom: -1px;
  left: 0;
  width: 100%;
  height: 60px;
  background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1200 120" preserveAspectRatio="none"><path d="M321.39,56.44c58-10.79,114.16-30.13,172-41.86,82.39-16.72,168.19-17.73,250.45-.39C823.78,31,906.67,72,985.66,92.83c70.05,18.48,146.53,26.09,214.34,3V0H0V27.35A600.21,600.21,0,0,0,321.39,56.44Z" fill="%23ffffff"></path></svg>');
  background-size: cover;
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ===== NAV ===== */
nav {
  position: sticky;
  top: 20px;
  z-index: 100;
  padding: 0 2rem;
  margin: -40px auto 3rem;
}

.nav-container {
  background: rgba(255, 255, 255, 0.98);
  backdrop-filter: blur(20px);
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 8px;
  padding: 1rem;
  border-radius: var(--radius-lg);
  max-width: 600px;
  margin: 0 auto;
  box-shadow: var(--shadow-lg);
  border: 1px solid rgba(255, 255, 255, 0.8);
}

.nav-link {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--primary);
  text-decoration: none;
  font-weight: 600;
  font-size: 1rem;
  padding: 0.8rem 1.5rem;
  border-radius: var(--radius-sm);
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.nav-link::before {
  content: "";
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(
    90deg,
    transparent,
    rgba(193, 250, 59, 0.2),
    transparent
  );
  transition: left 0.5s;
}

.nav-link:hover::before {
  left: 100%;
}

.nav-link:hover {
  background: var(--accent);
  color: var(--text-dark);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.nav-icon {
  font-size: 1.3rem;
}

/* ===== MAIN ===== */
main {
  max-width: 1400px;
  margin: 0 auto;
  padding: 2rem clamp(1rem, 5vw, 3rem) 4rem;
}

.content-card {
  background: var(--bg-light);
  padding: 3rem;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  margin-bottom: 3rem;
  border: 1px solid rgba(65, 66, 245, 0.08);
  position: relative;
  overflow: hidden;
  animation: fadeIn 0.6s ease-out backwards;
}

.content-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: linear-gradient(90deg, var(--primary), var(--accent));
}

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

.card-header {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  margin-bottom: 3rem;
  padding-bottom: 2rem;
  border-bottom: 2px solid rgba(65, 66, 245, 0.1);
}

.section-icon {
  width: 80px;
  height: 80px;
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-md);
  object-fit: cover;
}

.card-title-wrapper h2 {
  font-size: clamp(1.8rem, 4vw, 2.5rem);
  color: var(--primary);
  font-weight: 700;
  margin-bottom: 0.5rem;
  letter-spacing: -0.01em;
}

.card-subtitle {
  color: var(--text-light);
  font-size: 1.1rem;
  font-weight: 400;
}

/* ===== TOPICS GRID ===== */
.topics-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(400px, 100%), 1fr));
  gap: 2rem;
}

.topic-block {
  background: linear-gradient(135deg, #f8f9ff 0%, #ffffff 100%);
  padding: 2rem;
  border-radius: var(--radius-md);
  border: 2px solid rgba(65, 66, 245, 0.1);
  transition: var(--transition);
}

.topic-block:hover {
  border-color: var(--primary);
  box-shadow: var(--shadow-md);
  transform: translateY(-4px);
}

.topic-header {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 1.5rem;
  padding-bottom: 1rem;
  border-bottom: 2px solid rgba(65, 66, 245, 0.1);
}

.topic-icon {
  font-size: 2rem;
}

.topic-header h3 {
  flex: 1;
  font-size: 1.5rem;
  color: var(--primary);
  font-weight: 700;
  margin: 0;
}

.topic-badge {
  background: var(--accent);
  color: var(--text-dark);
  padding: 0.3rem 0.8rem;
  border-radius: 20px;
  font-size: 0.85rem;
  font-weight: 600;
}

.exercise-badge {
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  color: white;
}

/* ===== TOPIC LIST ===== */
.topic-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.topic-list li {
  margin-bottom: 0.8rem;
}

.topic-link {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 1rem 1.2rem;
  background: white;
  border-radius: var(--radius-sm);
  text-decoration: none;
  color: var(--text-dark);
  border: 1px solid rgba(65, 66, 245, 0.1);
  transition: var(--transition);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

.topic-link:hover {
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  color: white;
  border-color: transparent;
  transform: translateX(8px);
  box-shadow: var(--shadow-md);
}

.link-number {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  background: var(--accent);
  color: var(--text-dark);
  border-radius: 8px;
  font-weight: 700;
  font-size: 0.9rem;
  flex-shrink: 0;
}

.topic-link:hover .link-number {
  background: white;
  color: var(--primary);
}

.link-text {
  flex: 1;
  font-weight: 500;
}

.link-arrow {
  font-size: 1.2rem;
  opacity: 0;
  transform: translateX(-10px);
  transition: var(--transition);
}

.topic-link:hover .link-arrow {
  opacity: 1;
  transform: translateX(0);
}

/* ===== EXERCISE LIST ===== */
.exercise-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.exercise-list li {
  margin-bottom: 1rem;
}

.exercise-link {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
  padding: 1.2rem;
  background: white;
  border-radius: var(--radius-sm);
  text-decoration: none;
  color: var(--text-dark);
  border: 1px solid rgba(65, 66, 245, 0.1);
  transition: var(--transition);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

.exercise-link:hover {
  background: linear-gradient(135deg, #f8f9ff, white);
  border-color: var(--primary);
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.exercise-link.challenge {
  border: 2px solid var(--accent);
  background: linear-gradient(135deg, #fffef5, white);
}

.exercise-link.challenge:hover {
  background: var(--accent);
  border-color: var(--accent);
}

.exercise-icon {
  font-size: 1.8rem;
  flex-shrink: 0;
}

.exercise-content {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
}

.exercise-title {
  font-weight: 600;
  font-size: 1.05rem;
  color: var(--primary);
}

.exercise-link:hover .exercise-title {
  color: var(--primary-dark);
}

.exercise-link.challenge:hover .exercise-title {
  color: var(--text-dark);
}

.exercise-desc {
  font-size: 0.9rem;
  color: var(--text-light);
}

/* ===== RECURSOS ===== */
.resources-card {
  background: linear-gradient(
    135deg,
    var(--primary) 0%,
    var(--primary-dark) 100%
  );
  color: white;
}

.resources-card .card-title-wrapper h2,
.resources-card .card-subtitle {
  color: white;
}

.resources-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(250px, 100%), 1fr));
  gap: 1.5rem;
}

.resource-item {
  background: rgba(255, 255, 255, 0.15);
  backdrop-filter: blur(10px);
  padding: 2rem;
  border-radius: var(--radius-md);
  text-align: center;
  border: 1px solid rgba(255, 255, 255, 0.2);
  transition: var(--transition);
}

.resource-item:hover {
  background: rgba(255, 255, 255, 0.25);
  transform: translateY(-8px);
}

.resource-icon {
  font-size: 3rem;
  display: block;
  margin-bottom: 1rem;
}

.resource-item h4 {
  font-size: 1.3rem;
  margin-bottom: 0.5rem;
  font-weight: 600;
}

.resource-item p {
  opacity: 0.9;
  font-size: 0.95rem;
}

/* ===== FOOTER ===== */
footer {
  background: linear-gradient(
    135deg,
    var(--primary) 0%,
    var(--primary-dark) 100%
  );
  color: white;
  padding: 3rem 2rem 2rem;
  margin-top: 4rem;
  position: relative;
  overflow: hidden;
}

.footer-wave {
  position: absolute;
  top: -1px;
  left: 0;
  width: 100%;
  height: 60px;
  background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1200 120" preserveAspectRatio="none"><path d="M321.39,56.44c58-10.79,114.16-30.13,172-41.86,82.39-16.72,168.19-17.73,250.45-.39C823.78,31,906.67,72,985.66,92.83c70.05,18.48,146.53,26.09,214.34,3V0H0V27.35A600.21,600.21,0,0,0,321.39,56.44Z" fill="%23ffffff"></path></svg>');
  background-size: cover;
  transform: rotate(180deg);
}

.footer-content {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 2rem;
  align-items: center;
  text-align: center;
  position: relative;
  z-index: 1;
}

.footer-logo img {
  width: 80px;
  height: 80px;
  border-radius: 50%;
  margin: 0 auto 1rem;
  border: 3px solid rgba(255, 255, 255, 0.3);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.2);
}

.footer-tagline {
  font-size: 0.95rem;
  opacity: 0.9;
}

.footer-copyright {
  font-weight: 600;
  font-size: 1.1rem;
  margin-bottom: 0.3rem;
}

.footer-love {
  opacity: 0.9;
  font-size: 0.95rem;
}

.social-links {
  display: flex;
  justify-content: center;
  gap: 1.5rem;
  flex-wrap: wrap;
}

.social-link {
  display: inline-block;
  transition: var(--transition);
}

.social-link img {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.15);
  padding: 10px;
  transition: var(--transition);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

.social-link:hover img {
  transform: translateY(-6px) rotate(5deg) scale(1.1);
  background: var(--accent);
  box-shadow: 0 8px 24px rgba(193, 250, 59, 0.5);
}

/* ===== SCROLLBAR ===== */
::-webkit-scrollbar {
  width: 12px;
}

::-webkit-scrollbar-track {
  background: #f1f1f1;
}

::-webkit-scrollbar-thumb {
  background: var(--primary);
  border-radius: 6px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--primary-dark);
}

/* ===== ANIMACIONES ===== */
@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.content-card:nth-child(1) {
  animation-delay: 0.1s;
}
.content-card:nth-child(2) {
  animation-delay: 0.2s;
}
.content-card:nth-child(3) {
  animation-delay: 0.3s;
}

/* ===== RESPONSIVIDAD ===== */
@media (max-width: 768px) {
  header {
    padding: 3rem 1.5rem 4rem;
  }

  .logo-main {
    width: 100px;
    height: 100px;
  }

  nav {
    top: 10px;
    padding: 0 1rem;
  }

  .nav-container {
    flex-direction: column;
    gap: 6px;
    padding: 0.8rem;
  }

  .nav-link {
    width: 100%;
    justify-content: center;
  }

  .content-card {
    padding: 2rem 1.5rem;
  }

  .card-header {
    flex-direction: column;
    text-align: center;
  }

  .topics-grid {
    grid-template-columns: 1fr;
  }

  .footer-content {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
}

@media (max-width: 480px) {
  .content-card {
    padding: 1.5rem 1rem;
  }

  .topic-block {
    padding: 1.5rem;
  }

  .topic-link,
  .exercise-link {
    padding: 0.8rem;
  }

  .social-link img {
    width: 40px;
    height: 40px;
  }
}

/* ===== NAV ===== */
nav {
  position: sticky;
  top: 10px;
  z-index: 100;
  padding: 0 1rem;
  margin: -40px auto 2rem;
}

.nav-container {
  background: rgba(255, 255, 255, 0.98);
  backdrop-filter: blur(20px);
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 8px;
  padding: 0.8rem 1rem;
  border-radius: var(--radius-lg);
  max-width: 600px;
  margin: 0 auto;
  box-shadow: var(--shadow-lg);
  border: 1px solid rgba(255, 255, 255, 0.8);
}

.nav-link {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--primary);
  text-decoration: none;
  font-weight: 600;
  font-size: 1rem;
  padding: 0.8rem 1.5rem;
  border-radius: var(--radius-sm);
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.nav-link::before {
  content: "";
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(
    90deg,
    transparent,
    rgba(193, 250, 59, 0.2),
    transparent
  );
  transition: left 0.5s;
}

.nav-link:hover::before {
  left: 100%;
}

.nav-link:hover {
  background: var(--accent);
  color: var(--text-dark);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.nav-icon {
  font-size: 1.3rem;
}

/* ===== RESPONSIVIDAD NAV ===== */
@media (max-width: 768px) {
  nav {
    top: 8px;
    padding: 0 0.8rem;
    margin: -35px auto 1.5rem;
  }

  .nav-container {
    flex-direction: row;
    gap: 6px;
    padding: 0.6rem;
    border-radius: 50px;
    max-width: 95%;
  }

  .nav-link {
    flex: 1;
    justify-content: center;
    padding: 0.6rem 0.8rem;
    font-size: 0.85rem;
    gap: 6px;
  }

  .nav-icon {
    font-size: 1.1rem;
  }

  .nav-text {
    font-size: 0.85rem;
  }
}

@media (max-width: 480px) {
  nav {
    top: 5px;
    padding: 0 0.5rem;
    margin: -30px auto 1rem;
  }

  .nav-container {
    padding: 0.5rem;
    gap: 4px;
    border-radius: 40px;
  }

  .nav-link {
    padding: 0.5rem 0.6rem;
    font-size: 0.8rem;
    gap: 4px;
    border-radius: 8px;
  }

  .nav-icon {
    font-size: 1rem;
  }

  .nav-text {
    font-size: 0.75rem;
  }
}

/* Ocultar texto en pantallas muy pequeñas (opcional) */
@media (max-width: 360px) {
  .nav-text {
    display: none;
  }

  .nav-link {
    padding: 0.6rem;
  }

  .nav-icon {
    font-size: 1.2rem;
  }
}