antd-mobile/es/components/modal/modal.patch.css

<div align="center">

.adm-modal-body {
  font-size: 14px;
}
.adm-modal-title {
  font-size: 18px;
}
.adm-modal-content {
  font-size: 15px;
  color: #333333;
}
.adm-modal-close {
  color: #999999;
  font-size: 18px;
}
.adm-modal-footer.adm-space.adm-space-vertical > .adm-space-item.adm-space-item {
  margin-bottom: 20px;
}
.adm-modal-footer.adm-space.adm-space-vertical > .adm-space-item.adm-space-item:last-child {
  margin-bottom: 0;
}
.adm-modal-footer .adm-modal-button {
  font-size: 18px;
}