body {
  font-family: system-ui, sans-serif;
  background: #f8f9fa;
  margin: 0;
  padding: 0;
}
main {
  max-width: 600px;
  margin: 2rem auto;
  background: #fff;
  padding: 2rem;
  border-radius: 8px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.07);
}
form > div {
  margin-bottom: 1.5rem;
}
label {
  font-weight: 600;
  display: block;
  margin-bottom: 0.5rem;
}
textarea, input[type="text"] {
  width: 100%;
  font-size: 1rem;
  padding: 0.5rem;
  border: 1px solid #ccc;
  border-radius: 4px;
  box-sizing: border-box;
  resize: vertical;
}

/* Expandable preamble textarea styles */
#preamble {
  transition: height 0.3s ease;
  overflow-y: auto;
}

#preamble.expanded {
  height: 500px;
  resize: none;
}

#preamble.collapsed {
  height: auto;
  resize: vertical;
}

#togglePreamble {
  position: absolute;
  bottom: 8px;
  right: 8px;
  background: #007bff;
  color: #fff;
  font-size: 0.8rem;
  padding: 0.3rem 0.8rem;
  border: none;
  border-radius: 4px;
  cursor: pointer;
  transition: background 0.2s;
  z-index: 10;
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

#togglePreamble:hover {
  background: #0056b3;
}
textarea[readonly], input[readonly] {
  background: #f1f3f4;
}
button {
  margin-top: 0.5rem;
  padding: 0.4rem 1.2rem;
  font-size: 1rem;
  border: none;
  border-radius: 4px;
  background: #007bff;
  color: #fff;
  cursor: pointer;
  transition: background 0.2s;
}
button:hover {
  background: #0056b3;
}
header h1 {
  text-align: center;
}
footer {
  text-align: center;
}