body {
  font-family: sans-serif;
  margin: 0;
  background: #f7f7f7;
  width: 100vw;
  min-height: 100vh;
}

.container {
  background: #fff;
  padding: 24px;
  border-radius: 0;
  max-width: 100vw;
  width: 100vw;
  min-height: 100vh;
  box-sizing: border-box;
  display: flex;
  flex-direction: column;
  justify-content: flex-start;
  align-items: stretch;
}

label {
  font-weight: bold;
  margin-bottom: 12px;
  font-size: 1.1rem;
  width: 100%;
}

input[type="text"] {
  width: 100%;
  padding: 16px;
  margin-bottom: 18px;
  font-size: 1.2rem;
  box-sizing: border-box;
  border: 1px solid #ddd;
  border-radius: 8px;
  background: #f9f9f9;
}

.btn-area {
  display: flex;
  flex-direction: row;
  gap: 12px;
  margin-bottom: 24px;
  width: 100%;
}

button {
  font-size: 1.1rem;
  padding: 14px 0;
  flex: 1 1 0;
  border: none;
  border-radius: 8px;
  background: #2d8cf0;
  color: #fff;
  cursor: pointer;
  transition: background 0.2s;
}

button:hover {
  background: #1967b3;
}

#qrcode {
  margin-top: 24px;
  text-align: center;
  min-height: 120px;
  width: 100%;
  display: flex;
  justify-content: center;
  align-items: center;
}

#qrcode img,
#qrcode canvas {
  width: 90vw !important;
  max-width: 480px;
  height: auto !important;
  display: block;
  margin: 0 auto;
}

@media (max-width: 600px) {
  .container {
    padding: 10px;
  }
  input[type="text"] {
    font-size: 1.1rem;
    padding: 12px;
  }
  button {
    font-size: 1rem;
    padding: 14px 0;
  }
  .btn-area {
    flex-direction: column;
    gap: 10px;
  }
  #qrcode img,
  #qrcode canvas {
    width: 98vw !important;
    max-width: 98vw;
    min-width: 200px;
  }
}