body {
  font-family: "Hiragino Sans", "Meiryo", sans-serif;
  background: #f5f5f7;
  margin: 0;
  padding: 40px 16px;
}

.container {
  max-width: 720px;
  margin: 0 auto;
  background: white;
  padding: 32px;
  border-radius: 12px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
}

h1 {
  font-size: 22px;
  margin-bottom: 4px;
}

.task-table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 16px;
  font-size: 14px;
}

.task-table th, .task-table td {
  border-bottom: 1px solid #eee;
  padding: 8px;
  text-align: left;
}

.task-table tr.done {
  color: #999;
  text-decoration: line-through;
}

button {
  padding: 6px 12px;
  background: #2d6cdf;
  color: white;
  border: none;
  border-radius: 6px;
  font-size: 12px;
  cursor: pointer;
}