body {
  margin: 0;
  font-family: Arial, sans-serif;
  background-color: #0b1f3a;
  color: white;
}

.back-button {
  margin: 20px;
  padding: 8px 15px;
  background: white;
  color: #0b1f3a;
  border: none;
  border-radius: 5px;
  cursor: pointer;
}

.crypto-container {
  text-align: center;
  padding: 20px;
}

.crypto-options {
  display: flex;
  justify-content: center;
  gap: 20px;
  flex-wrap: wrap;
}

.crypto-option {
  background: #13294b;
  padding: 15px;
  border-radius: 10px;
  cursor: pointer;
  width: 120px;
  transition: 0.3s;
}

.crypto-option:hover {
  background: #1c3c6b;
}

.coin-logo {
  width: 40px;
  height: 40px;
}

.coin-name {
  margin-top: 10px;
}

.modal-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.6);
  justify-content: center;
  align-items: center;
}

.modal {
  background: white;
  color: black;
  width: 350px;
  padding: 25px;
  border-radius: 10px;
  text-align: center;
  position: relative;
}

.modal h3 {
  margin-top: 0;
  color: #0b1f3a;
}

.qr {
  width: 150px;
  height: 150px;
  margin: 10px auto;
}

.wallet-address {
  font-size: 12px;
  word-break: break-all;
  background: #f3f3f3;
  padding: 8px;
  border-radius: 5px;
}

.copy-btn {
  margin-top: 8px;
  padding: 6px 10px;
  border: none;
  background: #0b1f3a;
  color: white;
  border-radius: 5px;
  cursor: pointer;
}

.countdown {
  margin: 15px 0;
  font-weight: bold;
  color: red;
}

.cancel-btn {
  padding: 8px 15px;
  border: none;
  background: crimson;
  color: white;
  border-radius: 5px;
  cursor: pointer;
}

.loading-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.6);
  justify-content: center;
  align-items: center;
  z-index: 9999;
}

.spinner {
  border: 6px solid #f3f3f3;
  border-top: 6px solid #0b1f3a;
  border-radius: 50%;
  width: 50px;
  height: 50px;
  animation: spin 1s linear infinite;
}

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