:root {
      --primary-blue: #002d8a;
      --light-blue: #0066cc;
      --accent-blue: #00abf0;
      --text-light: #ccc;
      --white: #ffffff;
      --shadow: rgba(0, 45, 138, 0.2);
      --dark-text: #2c3e50;
      --success-green: #27ae60;
      --gradient-bg: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    }

    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }

    .btn-volver-container {
  text-align: center;
  margin: 40px 0;
}

.btn-volver {
  display: inline-block;
  background: linear-gradient(135deg, #007bff, #0056b3);
  color: #fff;
  padding: 12px 24px;
  font-size: 1rem;
  border: none;
  border-radius: 8px;
  text-decoration: none;
  font-weight: 500;
  box-shadow: 0 4px 12px rgba(0, 91, 187, 0.3);
  transition: all 0.3s ease;
}

.btn-volver:hover {
  background: linear-gradient(135deg, #0056b3, #003c82);
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(0, 91, 187, 0.5);
}


    body {
      font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
      background: var(--gradient-bg);
      min-height: 100vh;
      color: var(--dark-text);
      line-height: 1.6;
    }

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 20px;
    }

    header {
      text-align: center;
      margin-bottom: 40px;
      padding: 30px 0;
      background: linear-gradient(135deg, var(--primary-blue), var(--light-blue));
      border-radius: 20px;
      box-shadow: 0 15px 35px var(--shadow);
      position: relative;
      overflow: hidden;
    }

    header::before {
      content: '';
      position: absolute;
      top: -50%;
      left: -50%;
      width: 200%;
      height: 200%;
      background: radial-gradient(circle, rgba(255,255,255,0.1) 0%, transparent 70%);
      animation: rotate 20s linear infinite;
    }

    header h1 {
      color: var(--white);
      font-size: 2.5rem;
      font-weight: 700;
      text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
      position: relative;
      z-index: 2;
      margin-bottom: 10px;
    }

    .subtitle {
      color: var(--text-light);
      font-size: 1.1rem;
      position: relative;
      z-index: 2;
    }

    @keyframes rotate {
      0% { transform: rotate(0deg); }
      100% { transform: rotate(360deg); }
    }

    .selector {
      display: flex;
      justify-content: center;
      gap: 15px;
      margin-bottom: 40px;
      flex-wrap: wrap;
      background: var(--white);
      padding: 20px;
      border-radius: 20px;
      box-shadow: 0 10px 30px var(--shadow);
    }

    .selector button {
      background: linear-gradient(135deg, var(--primary-blue), var(--light-blue));
      color: var(--white);
      padding: 15px 30px;
      border: none;
      border-radius: 25px;
      cursor: pointer;
      font-size: 1.1rem;
      font-weight: 600;
      transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
      position: relative;
      overflow: hidden;
      box-shadow: 0 5px 15px var(--shadow);
    }

    .selector button::before {
      content: '';
      position: absolute;
      top: 0;
      left: -100%;
      width: 100%;
      height: 100%;
      background: linear-gradient(90deg, transparent, rgba(255,255,255,0.3), transparent);
      transition: left 0.5s;
    }

    .selector button:hover::before {
      left: 100%;
    }

    .selector button:hover {
      transform: translateY(-3px);
      box-shadow: 0 8px 25px var(--shadow);
    }

    .selector button.active {
      background: linear-gradient(135deg, var(--accent-blue), var(--light-blue));
      transform: translateY(-2px);
      box-shadow: 0 8px 25px rgba(0, 171, 240, 0.4);
    }

    .contenido {
      display: none;
      background: var(--white);
      padding: 40px;
      border-radius: 20px;
      box-shadow: 0 20px 60px var(--shadow);
      position: relative;
      overflow: hidden;
    }

    .contenido::before {
      content: '';
      position: absolute;
      top: 0;
      left: 0;
      right: 0;
      height: 5px;
      background: linear-gradient(90deg, var(--primary-blue), var(--accent-blue), var(--light-blue));
    }

    .contenido.active {
      display: block;
      animation: fadeInUp 0.6s ease-out;
    }

    @keyframes fadeInUp {
      from {
        opacity: 0;
        transform: translateY(30px);
      }
      to {
        opacity: 1;
        transform: translateY(0);
      }
    }

    .contenido img {
      max-width: 200px;
      display: block;
      margin: 0 auto 30px;
      border-radius: 15px;
      box-shadow: 0 10px 30px var(--shadow);
      transition: transform 0.3s ease;
    }

    .contenido img:hover {
      transform: scale(1.05);
    }

    .contenido h2 {
      text-align: center;
      color: var(--primary-blue);
      font-size: 2rem;
      margin-bottom: 30px;
      position: relative;
    }

    .contenido h2::after {
      content: '';
      position: absolute;
      bottom: -10px;
      left: 50%;
      transform: translateX(-50%);
      width: 60px;
      height: 3px;
      background: linear-gradient(90deg, var(--accent-blue), var(--light-blue));
      border-radius: 2px;
    }

    table {
      width: 100%;
      border-collapse: separate;
      border-spacing: 0;
      margin-top: 30px;
      border-radius: 15px;
      overflow: hidden;
      box-shadow: 0 10px 30px var(--shadow);
    }

    table th {
      background: linear-gradient(135deg, var(--primary-blue), var(--light-blue));
      color: var(--white);
      padding: 18px 15px;
      text-align: center;
      font-weight: 600;
      font-size: 1.1rem;
      text-transform: uppercase;
      letter-spacing: 1px;
    }

    table td {
      padding: 15px;
      text-align: center;
      border-bottom: 1px solid #e8ecf4;
      background: var(--white);
      transition: all 0.3s ease;
      font-weight: 500;
    }

    table tr:hover td {
      background: #f8fbff;
      transform: scale(1.02);
    }

    table tr:last-child td {
      border-bottom: none;
    }

    .modelo-img {
      width: 120px;
      height: auto;
      border-radius: 10px;
      box-shadow: 0 5px 15px var(--shadow);
      transition: transform 0.3s ease;
      margin-bottom: 10px;
    }

    .modelo-img:hover {
      transform: scale(1.1);
    }

    .precio {
      color: var(--success-green);
      font-weight: 700;
      font-size: 1.1rem;
    }

    .serie {
      font-family: 'Courier New', monospace;
      color: var(--primary-blue);
      font-weight: 600;
    }

    .marca {
      background: linear-gradient(135deg, var(--accent-blue), var(--light-blue));
      color: var(--white);
      padding: 5px 12px;
      border-radius: 20px;
      font-size: 0.9rem;
      font-weight: 600;
      display: inline-block;
    }

    /* Responsive Design */
    @media (max-width: 768px) {
      .container {
        padding: 10px;
      }
      
      header h1 {
        font-size: 2rem;
      }
      
      .selector {
        padding: 15px;
      }
      
      .selector button {
        padding: 12px 20px;
        font-size: 1rem;
      }
      
      .contenido {
        padding: 20px;
      }
      
      table th, table td {
        padding: 10px 8px;
        font-size: 0.9rem;
      }
      
      .modelo-img {
        width: 80px;
      }
    }

    /* Loading animation */
    .loading {
      display: inline-block;
      width: 20px;
      height: 20px;
      border: 3px solid rgba(255,255,255,.3);
      border-radius: 50%;
      border-top-color: var(--white);
      animation: spin 1s ease-in-out infinite;
    }

    @keyframes spin {
      to { transform: rotate(360deg); }
    }