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

body {
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  font-size: 1.25rem;
  background-color: #92C7CF;
  line-height: 1.5;
}

h1 {
  font-size: 1.875rem;
  margin-bottom: 0.5rem;
}

h2 {
  font-size: 1.5rem;
  margin-bottom: 0.75rem;
}

header,
main section,
footer {
  width: 90%;
  max-width: 900px;
  margin: 1.25rem auto;
  padding: 1.25rem;
  border-radius: 0.625rem;
  box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
  background-color: #fff;
}

p {
  margin-bottom: 0.75rem;
}

p:last-child {
  margin-bottom: 0;
}

ul {
  margin-left: 1.5rem;
  margin-bottom: 0.75rem;
}

li {
  margin-bottom: 0.5rem;
}

a {
  color: #397680;
  text-decoration: none;
  font-weight: bold;
}

a:hover,
a:focus {
  color: #5db4c2;
  outline: 2px solid #5db4c2;
  outline-offset: 2px;
  border-radius: 2px;
}

/* Navegación */
nav ul {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin: 0;
}

nav li {
  margin: 0;
}

nav .nav-right {
  margin-left: auto;
}

nav .nav-now a {
  font-style: italic;
}

/* Modo oscuro */
@media (prefers-color-scheme: dark) {
  body {
    background-color: #1a5c64;
    color: #e0e0e0;
  }

  header,
  main section,
  footer {
    background-color: #1e1e2e;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.3);
  }

  a {
    color: #7dd3d8;
  }

  a:hover,
  a:focus {
    color: #a8e8ec;
    outline-color: #a8e8ec;
  }
}