/* ベース */
*, *::before, *::after { box-sizing: border-box; }
body {
  max-width: 800px;
  margin: 0 auto;
  padding: 2rem 2rem 0;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Noto Sans JP", Meiryo, sans-serif;
  font-size: 16px;
  line-height: 1.7;
  color: #1f2328;
  background: #fff;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

main {
  flex: 1;
}

/* リンク */
a { color: #0969da; text-decoration: none; }
a:hover { text-decoration: underline; }

/* 見出し */
h1, h2, h3, h4, h5, h6 {
  margin-top: 1.5em;
  margin-bottom: 0.5em;
  font-weight: 600;
  line-height: 1.3;
}
h1 { font-size: 2em; padding-bottom: 0.3em; border-bottom: 1px solid #d1d9e0; }
h2 { font-size: 1.5em; padding-bottom: 0.3em; border-bottom: 1px solid #d1d9e0; }
h3 { font-size: 1.25em; }
h4 { font-size: 1em; }
h5 { font-size: 0.875em; }
h6 { font-size: 0.85em; color: #656d76; }

/* 段落・テキスト */
p { margin: 1em 0; }
strong { font-weight: 600; }
em { font-style: italic; }

/* リスト */
ul, ol { margin: 1em 0; padding-left: 2em; }
li { margin: 0.25em 0; }
li > ul, li > ol { margin: 0.25em 0; }

/* 引用 */
blockquote {
  margin: 1em 0;
  padding: 0 1em;
  color: #656d76;
  border-left: 4px solid #d1d9e0;
}
blockquote > :first-child { margin-top: 0; }
blockquote > :last-child { margin-bottom: 0; }

/* コード */
code {
  font-family: ui-monospace, "SFMono-Regular", "SF Mono", Menlo, Consolas, monospace;
  font-size: 0.875em;
  padding: 0.2em 0.4em;
  background: #f6f8fa;
  border-radius: 6px;
}
pre {
  margin: 1em 0;
  padding: 1em;
  overflow-x: auto;
  font-size: 0.875em;
  line-height: 1.5;
  background: #f6f8fa;
  border-radius: 6px;
}
pre code {
  padding: 0;
  background: none;
  font-size: inherit;
}

/* テーブル */
table {
  margin: 1em 0;
  border-collapse: collapse;
  width: 100%;
}
th, td {
  padding: 0.5em 1em;
  border: 1px solid #d1d9e0;
}
th {
  font-weight: 600;
  background: #f6f8fa;
}
tr:nth-child(even) { background: #f6f8fa; }

/* 水平線 */
hr {
  margin: 2em 0;
  border: 0;
  border-top: 1px solid #d1d9e0;
}

/* 画像 */
img {
  max-width: 100%;
  height: auto;
  border-radius: 6px;
}

/* Note/Warning/Important (GitHub Alerts) */
.markdown-alert {
  margin: 1em 0;
  padding: 0.5em 1em;
  border-left: 4px solid;
  border-radius: 6px;
}
.markdown-alert > :first-child { margin-top: 0; }
.markdown-alert > :last-child { margin-bottom: 0; }
.markdown-alert-title {
  display: flex;
  align-items: center;
  gap: 0.5em;
  font-weight: 600;
  margin-bottom: 0.25em;
}
.markdown-alert-note {
  border-color: #0969da;
  background: #ddf4ff;
}
.markdown-alert-note .markdown-alert-title { color: #0969da; }
.markdown-alert-tip {
  border-color: #1a7f37;
  background: #dafbe1;
}
.markdown-alert-tip .markdown-alert-title { color: #1a7f37; }
.markdown-alert-important {
  border-color: #8250df;
  background: #fbefff;
}
.markdown-alert-important .markdown-alert-title { color: #8250df; }
.markdown-alert-warning {
  border-color: #9a6700;
  background: #fff8c5;
}
.markdown-alert-warning .markdown-alert-title { color: #9a6700; }
.markdown-alert-caution {
  border-color: #cf222e;
  background: #ffebe9;
}
.markdown-alert-caution .markdown-alert-title { color: #cf222e; }

/* Mermaid */
pre.mermaid {
  background: transparent;
  text-align: center;
}

/* 記事 */
article { margin-top: 2rem; }
.post-date { color: #656d76; font-size: 0.9rem; }
.post-meta { color: #656d76; font-size: 0.9rem; }
.post-meta a { color: #656d76; }
.post-meta a:hover { color: #0969da; }

/* 記事一覧 */
.post-list {
  list-style: none;
  padding: 0;
  margin-top: 2rem;
}
.post-list li {
  margin-bottom: 0;
}
.post-list a {
  display: block;
  padding: 1.25rem 0;
  border-bottom: 1px solid #d1d9e0;
  color: inherit;
  transition: background 0.15s;
}
.post-list a:hover {
  background: #f6f8fa;
  text-decoration: none;
}
.post-list .post-title {
  font-size: 1.2rem;
  font-weight: 600;
  color: #0969da;
  margin-bottom: 0.25rem;
}
.post-list a:hover .post-title {
  text-decoration: underline;
}
.post-list .post-date {
  font-size: 0.85rem;
  color: #656d76;
}

/* フッター */
footer {
  margin-top: 4rem;
  padding: 2rem 0;
  border-top: 1px solid #d1d9e0;
  text-align: center;
  color: #656d76;
  font-size: 0.85rem;
}
footer p {
  margin: 0;
}