body {
  font-family: "Segoe UI", Meiryo, sans-serif;
  background: #f6f7fb;
  color: #333;
  margin: 2rem auto;
  max-width: 800px;
  padding: 0 1rem;
}
h1 { text-align: center; color: #004080; }
h2 { margin-top: 1.5em; font-size: 1.1rem; color: #005599; }
textarea, input[type="text"] {
  width: 100%;
  box-sizing: border-box;
  padding: 0.6em;
  font-size: 1rem;
  border: 1px solid #ccc;
  border-radius: 6px;
  resize: vertical;
}
input[readonly], textarea[readonly] {
  background: #f0f0f0;
  color: #555;
}
button {
  margin-top: 1em;
  padding: 0.8em 1.5em;
  font-size: 1rem;
  background: #0078d7;
  color: white;
  border: none;
  border-radius: 6px;
  cursor: pointer;
}
button:disabled { background: #aaa; cursor: not-allowed; }
#status {
  margin-top: 0.5em;
  font-weight: bold;
  color: #333;
  min-height: 1.2em;
}
details summary {
  cursor: pointer;
  margin-top: 1.5em;
  font-size: 1.1rem;
  color: #005599;
}
table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 0.5em;
  font-size: 0.9rem;
}
th, td {
  border: 1px solid #ccc;
  padding: 0.4em 0.6em;
}
th { background: #eee; text-align: left; }