body {
  font-family: Arial, sans-serif;
  margin: 0;
  padding: 40px;
  background: #f5f7fa;
  color: #333;
}

h1 {
  text-align: center;
  margin-bottom: 20px;
  font-size: 26px;
}

#searchSection {
  text-align: center;
  margin-bottom: 30px;
}

#placeholder {
  margin: 10px auto;
}

#authorIdInput {
  padding: 10px;
  width: 280px;
  border: 1px solid #ccc;
  border-radius: 6px;
  font-size: 14px;
}

#searchButton {
  padding: 10px 18px;
  margin-left: 10px;
  border: none;
  border-radius: 6px;
  background-color: #007bff;
  color: white;
  font-size: 14px;
  cursor: pointer;
  transition: background 0.2s;
}

#searchButton:hover {
  background-color: #0056b3;
}

#authorResult {
  max-width: 650px;
  margin: 20px auto;
  padding: 20px;
  background: #fff;
  border-radius: 8px;
  box-shadow: 0px 2px 8px rgba(0, 0, 0, 0.1);
}

#authorResult h2 {
  margin-top: 0;
}

#errorMessage {
  text-align: center;
  font-weight: bold;
}

#chartContainer {
  max-width: 600px;
  margin: 30px auto;
}

canvas {
  width: 100% !important;
  height: 500px !important;
}