.popup-overlay {
      position: fixed;
      inset: 0;
      background: rgba(0, 0, 0, 0.45);
      backdrop-filter: blur(6px);
      -webkit-backdrop-filter: blur(6px);
      display: flex;
      align-items: center;
      justify-content: center;
      padding: 20px;
      z-index: 9999;

      opacity: 0;
      visibility: hidden;
      transition: opacity 0.35s ease, visibility 0.35s ease;
    }

    .popup-overlay.show {
      opacity: 1;
      visibility: visible;
    }

    /* Popup box */
    .popup-banner {
      position: relative;
      width: min(92vw, 500px);
      background: rgba(255, 255, 255, 0.12);
      border: 1px solid rgba(255, 255, 255, 0.18);
      border-radius: 24px;
      padding: 28px 24px;
      text-align: center;
      box-shadow:
        0 20px 60px rgba(0, 0, 0, 0.35),
        inset 0 1px 0 rgba(255, 255, 255, 0.15);
      backdrop-filter: blur(16px);
      -webkit-backdrop-filter: blur(16px);
      overflow: hidden;

      transform: scale(0.85) translateY(30px);
      opacity: 0;
    }

    .popup-overlay.show .popup-banner {
      animation: popupIn 0.55s cubic-bezier(0.22, 1, 0.36, 1) forwards;
    }

    @keyframes popupIn {
      0% {
        opacity: 0;
        transform: scale(0.85) translateY(30px);
      }
      60% {
        opacity: 1;
        transform: scale(1.03) translateY(-4px);
      }
      100% {
        opacity: 1;
        transform: scale(1) translateY(0);
      }
    }

    /* Glow decoration */
    .popup-banner::before,
    .popup-banner::after {
      content: "";
      position: absolute;
      border-radius: 50%;
      filter: blur(45px);
      z-index: 0;
    }

    .popup-banner::before {
      width: 180px;
      height: 180px;
      background: rgba(99, 102, 241, 0.35);
      top: -60px;
      left: -40px;
    }

    .popup-banner::after {
      width: 160px;
      height: 160px;
      background: rgba(236, 72, 153, 0.28);
      bottom: -60px;
      right: -30px;
    }

    .popup-content {
      position: relative;
      z-index: 1;
    }

    .popup-badge {
      display: inline-block;
      padding: 8px 14px;
      margin-bottom: 14px;
      border-radius: 999px;
      background: rgba(255, 255, 255, 0.14);
      border: 1px solid rgba(255, 255, 255, 0.18);
      font-size: 0.85rem;
      letter-spacing: 0.4px;
      color: #e2e8f0;
    }

    .popup-banner h2 {
      font-size: clamp(1.5rem, 4vw, 2rem);
      margin-bottom: 12px;
      line-height: 1.2;
    }

    .popup-banner p {
      font-size: 1rem;
      line-height: 1.6;
      color: #e5e7eb;
      opacity: 0.95;
      margin-bottom: 22px;
    }

    .popup-actions {
      display: flex;
      gap: 12px;
      justify-content: center;
      flex-wrap: wrap;
    }

    .popup-btn {
      border: none;
      outline: none;
      cursor: pointer;
      padding: 12px 20px;
      border-radius: 14px;
      font-size: 0.95rem;
      font-weight: 600;
      transition: transform 0.25s ease, box-shadow 0.25s ease, opacity 0.25s ease;
    }

    .popup-btn:hover {
      transform: translateY(-2px);
    }

    .popup-btn.primary {
      background: linear-gradient(135deg, #6366f1, #8b5cf6);
      color: white;
      box-shadow: 0 12px 24px rgba(99, 102, 241, 0.35);
    }

    .popup-btn.secondary {
      background: rgba(255, 255, 255, 0.12);
      color: white;
      border: 1px solid rgba(255, 255, 255, 0.18);
    }

    .close-btn {
      position: absolute;
      top: 14px;
      right: 14px;
      width: 38px;
      height: 38px;
      border: none;
      border-radius: 50%;
      background: rgba(255, 255, 255, 0.12);
      color: white;
      font-size: 1.1rem;
      cursor: pointer;
      display: grid;
      place-items: center;
      transition: background 0.25s ease, transform 0.25s ease;
      z-index: 2;
    }

    .close-btn:hover {
      background: rgba(255, 255, 255, 0.2);
      transform: rotate(90deg);
    }

    /* Mobile tuning */
    @media (max-width: 480px) {
      .popup-banner {
        border-radius: 20px;
        padding: 24px 18px;
      }

      .popup-banner p {
        font-size: 0.95rem;
      }

      .popup-actions {
        flex-direction: column;
      }

      .popup-btn {
        width: 100%;
      }
    }