body {
      background-color: #F7F7F5;
      color: #222222;
      font-family: "游明朝", "Yu Mincho", "Hiragino Mincho ProN", serif;
      margin: 0;
      padding: 40px;
      line-height: 1.9;
    }

    h1 {
      font-size: 1.4rem;
      font-weight: normal;
      margin-bottom: 2rem;
    }

    .motivation {
      margin-bottom: 3rem;
      white-space: pre-line;
    }

    ul {
      list-style: none;
      padding-left: 0;
    }

    li {
      margin-bottom: 0.6rem;
    }

    .read {
      text-decoration: line-through;
    }
    footer {
  margin-top: 4rem;
  font-size: 0.8rem;
  color: #666666;
}
/* 文章が横に広がりすぎないようにする */
article, main, .container {
  max-width: 760px;   /* 700〜900で好み */
  margin: 0 auto;
}

/* 余白が欲しければ（bodyのpaddingがあるなら不要） */
@media (max-width: 860px) {
  article, main, .container {
    padding: 0 16px;
  }
}
.site-footer {
  margin-top: 4rem;
  padding-top: 1.5rem;
  border-top: 1px solid #ddd;
  font-size: 0.85rem;
  color: #666;
  text-align: center;
}


.back-to-library {
  position: absolute;
  top: 24px;
  left: 28px;

  color: #222222;
  text-decoration: none;
  font-size: 1.2rem;

  transition: color 0.18s ease;
}

.back-to-library:hover {
  color: #dc4813;
}