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

body {
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  background: #f3f4f6;
  color: #111827;
  padding: 20px;
}

.container {
  width: 100%;
  max-width: 500px;
  background: #ffffff;
  padding: 30px;
  border-radius: 20px;
  text-align: center;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.08);
}

h1 {
  margin-bottom: 10px;
  font-size: 36px;
}

.subtitle {
  margin-bottom: 25px;
  color: #6b7280;
  line-height: 1.5;
}

.input-box {
  display: flex;
  gap: 10px;
  margin-bottom: 25px;
}

#qrInput {
  flex: 1;
  padding: 12px 14px;
  border: 1px solid #d1d5db;
  border-radius: 10px;
  outline: none;
  font-size: 15px;
}

#qrInput:focus {
  border-color: #2563eb;
}

#generateBtn {
  border: none;
  background: #2563eb;
  color: white;
  padding: 12px 18px;
  border-radius: 10px;
  cursor: pointer;
  font-size: 14px;
}

#generateBtn:hover {
  background: #1d4ed8;
}

.qr-box {
  display: none;
  justify-content: center;
  align-items: center;
  padding: 20px;
  background: #f9fafb;
  border-radius: 16px;
}

.qr-box.show {
  display: flex;
}

#qrImage {
  width: 220px;
  height: 220px;
}

@media (max-width: 560px) {
  .input-box {
    flex-direction: column;
  }

  h1 {
    font-size: 30px;
  }
}