* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: "poppins", sans-serif;
}

body {
  background: linear-gradient(90deg, #e3ffe7 0%, #d9e7ff 100%);
}

.container {
  max-width: 80%;
  width: 400px;
  margin: 90px auto;
  padding: 30px 20px;
  background-color: #fff;
  border-radius: 10px;
  box-shadow: rgba(50, 50, 93, 0.25) 0px 50px 100px -20px,
    rgba(0, 0, 0, 0.3) 0px 30px 60px -30px,
    rgba(10, 37, 64, 0.35) 0px -2px 6px 0px inset;
}

h1 {
  font-size: 25px;
  margin-bottom: 30px;
}

input {
  padding: 20px 10px;
  color: #555;
  width: 100%;
  font-size: 18px;
  outline: none;
  border-radius: 6px;
  margin-bottom: 17px;
}

#qr-box {
  width: 200px;
  max-height: 0;
  overflow: hidden;
  transition: all 0.7s;
  border-radius: 6px;
}

#qr {
  width: 100%;
  padding: 10px;
}

#qr-box.show-img {
  max-height: 300px;
  margin: 30px auto;
  border: 1px solid #d1d1d1;
}

#btn {
  margin-top: 17px;
  color: #fff;
  background-color: #054a91;
  padding: 20px;
  width: 100%;
  transition: all 0.3s;
  border-radius: 6px;
  cursor: pointer;
  font-size: 18px;
}

#btn:hover {
  background-color: #0a3c6d;
}

.error {
  animation: shake 0.1s linear 10;
}

@keyframes shake {
  0% {
    transform: translateX(0);
  }
  25% {
    transform: translateX(-2px);
  }
  50% {
    transform: translateX(0);
  }
  75% {
    transform: translateX(2px);
  }
  100% {
    transform: translateX(0);
  }
}