body {
  margin: 0;
  background: #eee;
  font-family: "Helvetica Neue", Arial, sans-serif;
}

/* 中央寄せコンテナ */
.container {
  max-width: 960px;
  margin: 0 auto;
  background: white;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

/* ヘッダー */
.site-header {
  background: #000;
  color: white;
  padding: 1em;
}

.site-header .container {
  display: block;
  text-align: center;
}

.site-header h1 {
  margin: 0;
  font-size: 1.8em;
}

.site-header h1 a {
  text-decoration: none;
  color: white;
}

/* ナビゲーション */
.site-nav {
  margin-top: 0.5em;
}

.site-nav a {
  font-size: 1.1em;
  text-decoration: none;
  color: white;
  padding: 0.4em 0.6em;
}

.site-nav a:hover {
  background: #444;
  border-radius: 4px;
}

/* コンテンツ */
.site-content {
  padding: 2em;
}

/* フッター */
.site-footer {
  background: #777;
  color: white;
  padding: 1em;
  text-align: right;
  font-size: 0.9em;
}

.site-footer .footer-inner {
  max-width: 960px;
  margin: 0 auto;
  padding: 0 1em;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.site-footer .footer-inner a {
  color: white;
  text-decoration: none;
}

.site-footer .footer-inner a:hover {
  text-decoration: underline;
}

.site-header .container {
  display: block;
  padding: 1em;
}

/* タブを右寄せ */
.site-nav {
  text-align: right;
  margin-top: 0.5em;
}