@media (max-width: 768px) {

  .checkout-sticky-top {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 9999;

    display: flex;
    justify-content: center;
    align-items: center;

    padding: 10px 12px;

    background: rgba(255, 255, 255, 0.92);
    backdrop-filter: blur(10px);

    box-shadow: 0 4px 18px rgba(0, 0, 0, 0.12);

    transform: translateY(-120%);
    transition: transform 0.25s ease;
  }

  .checkout-sticky-top.visible {
    transform: translateY(0);
  }

  .checkout-sticky-top button {
    width: 100%;
    max-width: 420px;

    border-radius: 8px;

    padding: 14px 16px;

    font-size: 16px;
    font-weight: 600;

    display: flex;
    align-items: center;
    justify-content: center;

    text-align: center;

    box-shadow: 0 6px 18px rgba(0, 0, 0, 0.15);
  }

  body {
    padding-top: 0;
  }
}