* {
    box-sizing: border-box;
  }
  
  html {
    scroll-behavior: smooth;
  }
  
  body {
    font-family: 'Poppins', sans-serif;
    background-color: #afb2e0;
    margin: 0;
    padding: 0;
    display: flex;
  }
  
  nav {
    width: 220px;
    background-color: #3c5e75;
    padding: 20px;
    height: 100vh;
    position: sticky;
    top: 0;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    align-items: center;
  }
  
  nav img {
    width: 180px;
    display: block;
    margin: 10px auto 20px;
  }
  
  nav a {
    display: block;
    padding: 12px;
    margin-bottom: 10px;
    font-weight: bold;
    text-decoration: none;
    color: rgb(238, 203, 203);
    text-align: center;
    border-radius: 8px;
    width: 100%;
    transition: all 0.2s ease;
  }
  
  nav a:nth-child(3) {
    background-color: #5b9bd5;
  }
  nav a:nth-child(4) {
    background-color: #a6a6a6;
    color: #000;
  }
  nav a:nth-child(5) {
    background-color: #0074D9;
  }
  nav a:nth-child(6) {
    background-color: #5b9bd5;
  }
  nav a:nth-child(7) {
    background-color: #a6a6a6;
    color: #000;
  }
  nav a:nth-child(8) {
    background-color: #2528d4;
  }
  
  nav a:hover {
    filter: brightness(1.2);
    transform: scale(1.03);
  }
  
  main {
    flex: 1;
    padding: 30px;
  }
  
  section {
    background-color: rgba(129, 43, 155, 0.05);
    margin-bottom: 40px;
    padding: 25px;
    border-left: 6px solid #1184f0;
    border-radius: 10px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
  }
  
  h1, h2, h3 {
    text-align: center;
    margin-bottom: 15px;
    font-weight: 600;
  }
  
  h1 {
    font-size: 2.2em;
    color: #0056b3;
  }
  
  h2 {
    font-size: 1.8em;
    color: #4c4c4c;
  }
  
  h3 {
    font-size: 1.4em;
    color: #0074D9;
  }
  
  p {
    text-align: justify;
    font-size: 1em;
    margin-bottom: 15px;
    color: #333;
  }
  
  table.primera {
    width: 100%;
    border-collapse: collapse;
    margin-top: 15px;
    font-size: 0.95em;
  }
  
  table.primera th,
  table.primera td {
    border: 1px solid #999;
    padding: 10px;
    text-align: left;
  }
  
  table.primera th {
    background-color: #cce4ff;
    color: #003366;
  }
  
  ul {
    margin-left: 20px;
    margin-bottom: 15px;
  }
  
  li {
    margin-bottom: 10px;
  }
  
  img.center {
    display: block;
    margin-left: auto;
    margin-right: auto;
    max-width: 95%;
    height: auto;
    border: 4px solid #7ac6ff;
    border-radius: 10px;
    box-shadow: 0 0 15px rgba(0, 0, 0, 0.2);
    margin-top: 30px;
    margin-bottom: 30px;
  }
  
  footer {
    width: 100%;
    background-color: #ececec;
    padding: 15px;
    text-align: center;
    color: #333;
    font-size: 0.9em;
    margin-top: 40px;
  }
  
  @media (max-width: 800px) {
    body {
      flex-direction: column;
    }
  
    nav {
      width: 100%;
      height: auto;
      flex-direction: row;
      flex-wrap: wrap;
      justify-content: center;
      position: static;
    }
  
    nav a {
      flex: 1 1 calc(33.33% - 20px);
      margin: 10px;
      text-align: center;
      min-width: 100px;
      box-sizing: border-box;
    }
  
    main {
      padding: 20px;
    }
  
    h1 {
      font-size: 1.6em;
    }
  
    h2 {
      font-size: 1.3em;
    }
  
    h3 {
      font-size: 1.1em;
    }
  
    img.center {
      max-width: 100%;
    }
  }