#login-modal {
  display: none;
  position: fixed;
  z-index: 1000;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  overflow: auto;
  background-color: rgba(0, 0, 0, 0.5);
}
#login-modal .modal-content {
  background-color: #fff;
  margin: 10% auto;
  padding: 20px;
  border: 1px solid #888;
  width: 300px;
  border-radius: 4px;
}
#login-modal input {
  width: 100%;
  padding: 8px;
  margin: 5px 0;
  box-sizing: border-box;
}
#login-modal button {
  width: 100%;
  padding: 8px;
  margin-top: 10px;
}
#register-form { display: none; }