body {
      background-color: #0b0f19;
      color: #fff;
      font-family: 'Poppins', sans-serif;
      margin: 0;
      padding: 0;
      text-align: center;
    }

    /* Header / Back Link */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      padding: 15px 30px;
      background: rgba(0, 0, 0, 0.6);
      z-index: 100;
      text-align: left;
    }

    .header a {
      color: #00eaff;
      text-decoration: none;
      font-weight: 600;
      font-size: 16px;
      display: inline-flex;
      align-items: center;
      transition: color 0.3s ease;
    }

    .header a:hover {
      color: #0af;
      text-shadow: 0 0 10px #00eaff;
    }

    .header a .arrow {
      margin-right: 8px;
      font-size: 18px;
    }

    /* Page padding to avoid header overlap */
    .page-content {
      padding: 100px 20px 50px;
      max-width: 1200px;
      margin: 0 auto;
    }

    .section-title {
      font-size: 2.2rem;
      margin-bottom: 40px;
      color: #fff;
    }

    .section-title span {
      color: #00eaff;
    }

    .cert-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
      gap: 30px;
      justify-items: center;
    }

    .cert-card {
      position: relative;
      background: rgba(255,255,255,0.05);
      border: 1px solid rgba(0,234,255,0.2);
      border-radius: 15px;
      overflow: hidden;
      perspective: 1000px;
      transition: all 0.3s ease;
      color: #fff;
      transform: translateY(60px);
      opacity: 0;
      width: 100%;
      max-width: 320px;
    }

    .cert-card.show {
      opacity: 1;
      transform: translateY(0);
      transition: all 0.8s ease;
    }

    .cert-glow {
      position: absolute;
      top: 50%;
      left: 50%;
      width: 300%;
      height: 300%;
      background: radial-gradient(circle, rgba(0,234,255,0.2), transparent 60%);
      z-index: 0;
      pointer-events: none;
      transform: translate(-50%, -50%);
      transition: transform 0.2s ease;
      filter: blur(50px);
    }

    .cert-inner {
      transform-style: preserve-3d;
      transition: transform 0.2s ease;
    }

    .cert-inner img {
      width: 100%;
      height: 200px;
      object-fit: cover;
      border-bottom: 2px solid #00eaff33;
      display: block;
      position: relative;
      z-index: 1;
    }

    .cert-content {
      padding: 20px;
      position: relative;
      z-index: 2;
    }

    .cert-content h3 {
      font-size: 1.2rem;
      margin-bottom: 10px;
      color: #fff;
    }

    .cert-content p {
      font-size: 0.95rem;
      color: #ccc;
      margin-bottom: 15px;
    }

    .cert-content a {
      display: inline-block;
      text-decoration: none;
      color: #00eaff;
      font-weight: 600;
      padding: 8px 15px;
      border-radius: 8px;
      transition: all 0.3s ease;
    }

    .cert-content a:hover {
      color: #0af;
      text-shadow: 0 0 10px #00eaff;
    }

    @media (max-width: 1024px) { .cert-inner img { height: 180px; } }
    @media (max-width: 768px) { .cert-grid { grid-template-columns: repeat(2, 1fr); } .cert-inner img { height: 160px; } }
    @media (max-width: 480px) { .cert-grid { grid-template-columns: 1fr; } .cert-inner img { height: 140px; } }