.checkout-overlay { position: fixed; inset: 0; z-index: 1100; display: none;
  align-items: flex-start; justify-content: center; overflow-y: auto;
  background: rgba(5,8,12,0.8); backdrop-filter: blur(6px); padding: 40px 16px; }
.checkout-overlay.open { display: flex; }
.checkout-modal { position: relative; width: 100%; max-width: 480px;
  background: var(--card, #0f172a); border: 1px solid rgba(255,255,255,0.08);
  border-radius: 16px; padding: 20px; }
.checkout-close { position: absolute; top: 14px; right: 18px; background: none;
  border: none; color: var(--text-secondary, #8892a8); font-size: 1.4rem; cursor: pointer; z-index: 2; }
#checkout-container { min-height: 360px; }
.checkout-error { color: #f87171; font-size: 0.9rem; padding: 12px; }