body {
      font-family: 'Poppins', sans-serif;
      margin: 0;
      background: linear-gradient(135deg, #0b0c2a, #1b1e5f, #2e307a);
      color: #e6e6e6;
      line-height: 1.6;
    }
#menu {
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  transition: all 0.4s ease;
  padding: 10px 5%;
  position: fixed; 
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

.navbar-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  max-width: 1200px;
  margin: auto;
}

.navbar-brand {
  text-transform: uppercase;
  font-size: 24px;
  font-weight: 900;
  color: #4a90e2;
  text-decoration: none;
  display: flex;
  align-items: center;
}

.logo {
  height: 40px;
  margin-right: 10px;
}

.navbar-nav {
  list-style: none;
  display: flex;
  gap: 20px;
  margin: 0;
  padding: 0;
}

.navbar-nav li a {
  text-transform: uppercase;
  color: #555;
  font-size: 13px;
  letter-spacing: 1px;
  text-decoration: none;
  transition: color 0.3s ease;
}

.navbar-nav li a:hover {
  color: #ff7b54;
}


.navbar-toggle {
  display: none;
  font-size: 28px;
  background: none;
  border: none;
  cursor: pointer;
}


@media (max-width: 768px) {
  .navbar-nav {
    flex-direction: column;
    display: none;
    background: rgba(255, 255, 255, 0.95);
    position: absolute;
    top: 60px;
    right: 5%;
    width: 90%;
    padding: 15px;
    border-radius: 10px;
    box-shadow: 0 0 10px rgba(0,0,0,0.1);
  }

  .navbar-nav.show {
    display: flex;
  }

  .navbar-toggle {
    display: block;
  }
}

    a {
      text-decoration: none;
      color: inherit;
    }

    header {
      background: url('experimento4.png') center/cover no-repeat;
      height: 50vh;
      display: flex;
      align-items: center;
      justify-content: center;
      position: relative;
      filter: brightness(0.6);
    }

    header h1 {
      position: absolute;
      color: #fff;
      text-align: center;
      font-size: 2rem;
      padding: 0 1rem;
      text-shadow: 0 3px 10px rgba(0,0,0,0.7);
    }

    .container {
      max-width: 1000px;
      margin: 2rem auto;
      padding: 0 1rem;
    }

    article {
      background: rgba(255,255,255,0.05);
      border-radius: 15px;
      padding: 1.5rem;
      margin-bottom: 2rem;
      box-shadow: 0 6px 15px rgba(0,0,0,0.3);
      transition: transform 0.3s, background 0.3s;
    }

    article:hover {
      transform: translateY(-5px);
      background: rgba(255,255,255,0.1);
    }

    article h2 {
      color: #fff;
      margin-bottom: 0.5rem;
      border-left: 5px solid #6b5cff;
      padding-left: 10px;
    }

    article .meta {
      font-size: 0.9rem;
      color: #aaa;
      margin-bottom: 1rem;
    }

    .article-image {
      width: 100%;
      height: 200px;
      object-fit: cover;
      border-radius: 10px;
      margin-bottom: 1rem;
    }


    .buttons {
      display: flex;
      justify-content: center;
      gap: 1rem;
      flex-wrap: wrap;
      margin: 2rem 0;
    }

    .btn {
      background: #5a3df0;
      color: #fff;
      padding: 0.7rem 1.3rem;
      border-radius: 2rem;
      font-weight: 500;
      box-shadow: 0 4px 12px rgba(0,0,0,0.3);
      transition: background 0.3s, transform 0.2s;
    }

    .btn:hover {
      background: #7b5cff;
      transform: translateY(-2px);
    }

    .btn.back {
      background: #2b82f6;
    }

    .btn.back:hover {
      background: #509cff;
    }

    footer {
      text-align: center;
      font-size: 0.9rem;
      padding: 2rem 1rem;
      background: rgba(0,0,0,0.4);
      color: #aaa;
    }

    @media (max-width: 700px) {
      header h1 {
        font-size: 1.5rem;
      }

      .btn {
        padding: 0.6rem 1rem;
        font-size: 0.9rem;
      }

      .article-image {
        height: 150px;
      }
    }