* { box-sizing: border-box; }
body {
  font-family: system-ui, sans-serif;
  padding: 1rem;
  margin: 0;
  background-color: #f9f9f9;
  color: #222;
}
.container {
  max-width: 500px;
  margin: 0 auto;
  background: white;
  border-radius: 10px;
  box-shadow: 0 0 8px rgba(0,0,0,0.1);
  padding: 1.2rem;
}
h2 {
  text-align: center;
  font-size: 1.5rem;
}
label {
  margin-top: 1rem;
  display: block;
  font-weight: 600;
}
input, select, button {
  width: 100%;
  padding: 12px;
  margin-top: 6px;
  margin-bottom: 1rem;
  border: 1px solid #ccc;
  border-radius: 6px;
  font-size: 1rem;
}
button {
  background-color: #007bff;
  color: white;
  font-weight: bold;
  cursor: pointer;
  transition: background-color 0.2s ease;
}
button:hover {
  background-color: #0056b3;
}
canvas {
  display: block;
  margin: 1.5rem auto;
  max-width: 100%;
  height: auto;
}
.result {
  font-family: monospace;
  font-size: 0.95em;
  word-break: break-word;
  background: #f1f1f1;
  border-radius: 6px;
  padding: 0.8rem;
  margin-top: 0.5rem;
  position: relative;
  display: none;
}
#keyText {
  cursor: pointer;
}
.copy-icon {
  vertical-align: middle;
  margin-left: 8px;
}
@media (max-width: 400px) {
  h2 { font-size: 1.25rem; }
  input, select, button { font-size: 0.95rem; padding: 10px; }
  .result { font-size: 0.85rem; padding: 0.6rem; }
}