/* ======================= */
/* RESET BÁSICO / BASE     */
/* ======================= */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

/* BODY */
body {
  background-color: #f5faff;
  color: #1a1a1a;
  line-height: 1.6;
}

/* NAVEGACIÓN */
nav {
  background-color: #e0f0ff;
  padding: 15px 30px;
  display: flex;
  flex-wrap: wrap;
  gap: 15px;
  justify-content: center;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

nav a {
  text-decoration: none;
  color: #0077cc;
  font-weight: 600;
  padding: 8px 12px;
  border-radius: 5px;
  transition: background-color 0.3s, color 0.3s;
}

nav a:hover {
  background-color: #0077cc;
  color: #ffffff;
}

/* MAIN */
main {
  max-width: 900px;
  margin: 40px auto;
  padding: 0 20px;
}

/* TITULOS */
article h1 {
  font-size: 2.5rem;
  margin-bottom: 20px;
  color: #0077cc;
  text-align: center;
}

article h2 {
  font-size: 1.8rem;
  margin-top: 25px;
  margin-bottom: 15px;
  color: #005a99;
}

article h3 {
  font-size: 1.5rem;
  margin-top: 20px;
  margin-bottom: 15px;
  color: #005a99;
  border-left: 4px solid #0077cc;
  padding-left: 10px;
}

/* PARRAFOS, LISTAS, FORMULARIOS */
p, ul li, ol li {
  font-size: 1.05rem;
  line-height: 1.85;
  margin-bottom: 15px;
}

ul, ol {
  padding-left: 25px;
}

strong {
  color: #0077cc;
}

form {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin: 15px 0;
}

form label {
  font-weight: 600;
}

form input, form select, form button {
  padding: 8px 10px;
  border-radius: 5px;
  border: 1px solid #b3d4f5;
  font-size: 1rem;
}

form button {
  background-color: #0077cc;
  color: #fff;
  font-weight: 700;
  cursor: pointer;
  transition: background-color 0.3s;
}

form button:hover {
  background-color: #005a99;
}

/* RESULTADO */
#resultado {
  margin-top: 10px;
  font-weight: 600;
  color: #1a1a1a;
}

/* FOOTER */
footer {
  background-color: #e0f0ff;
  text-align: center;
  padding: 20px 10px;
  margin-top: 40px;
  color: #0077cc;
  font-size: 0.9rem;
}

footer a {
  color: #0077cc;
  text-decoration: none;
  margin: 0 5px;
}

footer a:hover {
  text-decoration: underline;
}

/* RESPONSIVE */
@media (max-width: 768px) {
  nav {
    flex-direction: column;
    align-items: center;
  }
  article h1 {
    font-size: 2rem;
  }
  article h2 {
    font-size: 1.5rem;
  }
  article p, ul li, ol li, form input, form select, form button {
    font-size: 0.95rem;
  }
}

@media (max-width: 480px) {
  nav a {
    width: 100%;
    text-align: center;
    padding: 10px 0;
  }
  main {
    margin: 20px 10px;
    padding: 0 10px;
  }
  article h1 {
    font-size: 1.8rem;
  }
  article h2 {
    font-size: 1.3rem;
  }
  article p, ul li, ol li, form input, form select, form button {
    font-size: 0.85rem;
    padding: 5px;
  }
}