/* styles.css - versión validable en CSS3 sin errores */

/* Reset básico */
* {
  box-sizing: border-box;
}

html, body {
  height: 100%;
  margin: 0;
  padding: 0;
  font-family: Arial, sans-serif;
  color: #000000;
  line-height: 1.4;
}

/* Header */
header {
  background-color: #4caf50;
  color: #ffffff;
  text-align: center;
  padding: 1em;
}

/* Navegación */
nav {
  background-color: silver;
  text-align: center;
  padding: 0.5em;
}

nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
}

nav li {
  display: inline-block;
  margin-right: 1em;
}

nav a {
  color: #000000;
  text-decoration: none;
}

/* Contenedor principal */
main {
  padding: 1em;
  max-width: 1200px;
  margin: 0 auto;
}

/* Sección Home */
section#home img {
  display: block;
  max-width: 100%;
  height: auto;
}

/* Botón */
section#home button {
  background-color: #4caf50;
  color: #ffffff;
  padding: 0.5em 1em;
  border: none;
  cursor: pointer;
  font: inherit;
}

/* Estado de foco accesible */
section#home button:focus,
nav a:focus {
  outline: 3px solid #999999;
}

/* Footer */
footer {
  background-color: silver;
  text-align: center;
  padding: 0.5em;
  clear: both;
}

footer p {
  margin: 0;
}

/* Media queries */
@media screen and (max-width: 600px) {
  header h1 {
    font-size: 1.5em;
  }

  nav li {
    display: block;
    width: 100%;
    text-align: center;
    margin: 0 0 0.5em 0;
  }

  main {
    padding: 0.5em;
  }

  section#home button {
    width: 100%;
    margin-bottom: 0.5em;
  }
}

@media screen and (min-width: 601px) and (max-width: 960px) {
  header h1 {
    font-size: 2em;
  }

  nav li {
    display: inline-block;
    width: auto;
    text-align: center;
    margin-bottom: 0;
  }

  main {
    padding: 1em;
  }

  section#home button {
    width: auto;
    margin-bottom: 0;
  }
}

@media screen and (min-width: 961px) {
  header h1 {
    font-size: 2.5em;
  }

  nav li {
    display: inline-block;
    width: auto;
    text-align: center;
    margin-bottom: 0;
  }

  main {
    padding: 1em;
  }

  section#home button {
    width: auto;
    margin-bottom: 0;
  }
}