/* ——— Reset básico ——— */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
  }
  
  /* ——— Base ——— */
  body {
    font-family: Arial, sans-serif;
    font-size: 11pt;
    line-height: 1.6;
    color: #e8ecf2; /* texto claro sobre fondo oscuro */
    background: linear-gradient(135deg, #1b2735, #2e3c4f);
    background-attachment: fixed;
  }
  
  /* ——— Contenedor principal ——— */
  header, main, footer {
    max-width: 900px;
    margin: 0 auto 20px auto;
    padding: 20px;
    background-color: #263445;          /* panel oscuro para no “quemar” el blanco */
    border-radius: 8px;
    border: 1px solid #3b4b5f;
    box-shadow: 0 2px 8px rgba(0,0,0,0.25);
  }
  
  /* ——— Header ——— */
  header {
    text-align: center;
    border-bottom: none;
    margin-top: 20px;
    box-shadow: none;
  }
  
  h1 {
    font-size: 26px;
    margin-bottom: 8px;
    color: #f0f3f7;                      /* título claro */
  }
  
  header p {
    color: #c8d3e0;                      /* subtítulo suavizado */
    font-size: 10.5pt;
    margin-bottom: 12px;
  }
  
  /* ——— Navegación ——— */
  nav {
    margin: 12px 0;
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 10px;
  }
  
  nav a {
    text-decoration: none;
    color: #f0f3f7;
    background-color: #3a4b63;
    border: 1px solid #51657f;
    padding: 8px 14px;
    border-radius: 6px;
    transition: background-color 0.2s, color 0.2s;
  }
  
  nav a:hover {
    background-color: #f0f3f7;          /* invertimos para resaltar */
    color: #1b2735;
  }
  
  /* ——— Cuerpo principal ——— */
  main {
    margin-top: 20px;
    border-top: none;
    border-bottom: none;
  }
  
  h2 {
    color: #f0f3f7;
    margin-bottom: 10px;
  }
  
  p {
    margin-bottom: 14px;
    text-align: justify;
    color: #e8ecf2;
  }
  
  /* ——— Imágenes y figuras ——— */
  figure {
    margin: 16px 0;
    text-align: center;
  }
  
  figure img {
    max-width: 100%;
    height: auto;
    border-radius: 6px;
    border: 1px solid #46566c;
  }
  
  figcaption {
    font-size: 10pt;
    color: #b8c3d0;
    margin-top: 6px;
    font-style: italic;
  }
  
  /* ——— Aside o notas ——— */
  .aside {
    color: #f0f3f7;
    background-color: #34465a;
    border-left: 4px solid #82aaff;
    padding: 8px 12px;
    border-radius: 4px;
    font-style: italic;
  }
  
  /* ——— Footer ——— */
  footer {
    text-align: center;
    font-size: 10pt;
    color: #b0bbca;
    border-top: none;
  }
  
  /* ——— Responsivo sencillo ——— */
  @media (max-width: 640px) {
    body { font-size: 10.5pt; }
    nav { flex-direction: column; align-items: center; }
  }