/* リセット気味 */
* {
  box-sizing: border-box;
}

.base {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: #222;
  /* background: #f2f3f5; */
}

/* ヘッダー */
.site-header {
  background: #fff;
  border-bottom: 1px solid rgba(0,0,0,0.05);
}

.header-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 1rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

nav a {
  margin-left: 1.5rem;
  text-decoration: none;
  color: #666;
  font-size: 0.9rem;
}

/* 土台 */
.base {
  padding: 4rem 1rem;
}

/* 白い紙 */
.sheet {
  max-width: 820px;
  margin: 0 auto;
  padding: 3.5rem;
  background: #fff;
  margin-top:3em;

  border: 1px solid #e0e0e0;
  border-radius: 12px;
  box-shadow: 0 4px 12px rgba(0,0,0,0.04);
}

/* 見出し */
.sheet h2 {
  font-size: 2rem;
  margin: 0 0 0.5rem;
}

.sheet .sub {
  font-size: 0.9rem;
  color: #888;
  margin-bottom: 2rem;
}

.sheet p {
  line-height: 1.9;
  font-size: 0.95rem;
}

/* フッター */
.site-footer {
  text-align: center;
  padding: 3rem 0;
  font-size: 0.8rem;
  color: #888;
}

.author-sign {
  display: flex;
  align-items: center;
  gap: 0.8rem;
  opacity: 0.8;
  margin-bottom: 0.5rem; /* ここだけ */
}


.author-sign img {
  width: 48px;
  height: 48px;
  border-radius: 50%;
}

.author-sign span {
  font-size: 0.85rem;
  color: #888;
}

.sheet h2 {
  margin-top: 0;
}

.sheet p {
  line-height: 1.9;
}

.sheet p:last-of-type {
  color: #555;
}