/* ===============================
   VARIABLES GLOBALES
================================= */
:root {
  --color-dark: #2c3e50;
  --color-light: #ecf0f1;
  --color-accent: #1abc9c;
  --color-primary: #2980b9;
  --color-primary-hover: #1f6391;

  --font-main: 'Poppins', sans-serif;
  --shadow-card: 0 12px 24px rgba(0, 0, 0, 0.15);
  --shadow-btn: 0 4px 15px rgba(0,0,0,0.2);
  --radius-card: 1rem;
  --radius-btn: 0.5rem;
}

/* ===============================
   ESTILOS BASE
================================= */
html, body {
  height: 100%;
  margin: 0;
  padding: 0;
}

body {
  display: flex;
  flex-direction: column;
  font-family: var(--font-main);
  background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
  scroll-behavior: smooth;
}

/* ===============================
   MAIN
================================= */
main {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 2rem 0;
}

/* ===============================
   NAVBAR
================================= */
.navbar {
  background-color: var(--color-dark) !important;
  padding: 0.8rem 1rem;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.navbar-brand {
  color: var(--color-light) !important;
  font-weight: 700;
  font-size: 1.4rem;
}

.navbar-brand img {
  height: 50px;
}

.navbar-nav .nav-link {
  color: var(--color-light);
  font-weight: 500;
  margin-left: 1.2rem;
  transition: all 0.3s ease;
}

.navbar-nav .nav-link:hover,
.navbar-nav .nav-link.active {
  color: var(--color-accent);
  text-decoration: underline;
}

/* ===============================
   CARD COMPONENT
================================= */
.card {
  border-radius: var(--radius-card);
  box-shadow: var(--shadow-card);
  transition: transform 0.3s ease-out, box-shadow 0.3s ease-out;
  will-change: transform;
  background-color: #fff;
  padding: 2rem;
  animation: fadeInUp 0.7s ease-out;
}

.card:hover {
  transform: translateY(-8px);
  box-shadow: 0 20px 40px rgba(0,0,0,0.2);
}

.card h1 {
  font-size: 2.2rem;
  color: var(--color-dark);
  margin-bottom: 0.5rem;
}

.card p.lead {
  font-size: 1.15rem;
  color: #555;
  margin-bottom: 1.5rem;
}

.card img {
  max-width: 120px;
  margin-bottom: 1rem;
}

/* ===============================
   BOTONES
================================= */
.btn-primary {
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
  color: #fff;
  font-weight: 600;
  border: none;
  font-size: 1.1rem;
  padding: 0.65rem 2rem;
  border-radius: var(--radius-btn);
  box-shadow: var(--shadow-btn);
  transition: all 0.3s ease;
}

.btn-primary:hover {
  background-color: var(--color-primary-hover);
  transform: translateY(-2px);
  box-shadow: 0 6px 18px rgba(0,0,0,0.25);
}

/* ===============================
   FOOTER
================================= */
footer {
  background-color: var(--color-dark);
  color: var(--color-light);
  text-align: center;
  padding: 1rem 0;
  font-size: 0.9rem;
  border-radius: 0.5rem 0.5rem 0 0;
}

footer a {
  color: var(--color-accent);
  text-decoration: none;
  transition: all 0.3s ease;
}

footer a:hover {
  text-decoration: underline;
  color: #16a085;
}

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

/* ===============================
   RESPONSIVE
================================= */
@media (max-width: 576px) {
  .card {
    padding: 1.5rem;
  }

  .btn-primary {
    font-size: 1rem;
    padding: 0.5rem 1.5rem;
  }

  .navbar-brand {
    font-size: 1.25rem;
  }

  footer {
    font-size: 0.8rem;
  }
}