:root {
  --bg: #f6f7f9;
  --card: #ffffff;
  --text: #1d2330;
  --muted: #6b7280;
  --border: #e3e6eb;
  --accent: #f38020;
  --accent-hover: #d96d10;
  --error: #c62828;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #14161b;
    --card: #1e2128;
    --text: #e8eaef;
    --muted: #9aa1ad;
    --border: #2e333d;
    --error: #ff6b6b;
  }
}

* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Noto Sans JP", sans-serif;
  line-height: 1.7;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

.site-header {
  background: var(--card);
  border-bottom: 1px solid var(--border);
  padding: 12px 16px;
}
.logo { font-weight: 700; font-size: 1.2rem; color: var(--text); }

.container { max-width: 720px; margin: 0 auto; padding: 24px 16px 64px; }
.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 20px;
  margin-bottom: 24px;
}
h2 { margin: 0 0 12px; font-size: 1.15rem; }
.section-title { font-size: 1rem; color: var(--muted); }

.form { display: grid; gap: 10px; }
input, textarea {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--bg);
  color: var(--text);
  font: inherit;
}
textarea { resize: vertical; }
button {
  justify-self: end;
  padding: 10px 20px;
  border: 0;
  border-radius: 8px;
  background: var(--accent);
  color: #fff;
  font: inherit;
  font-weight: 600;
  cursor: pointer;
}
button:hover { background: var(--accent-hover); }
button:disabled { opacity: .6; cursor: wait; }
.error { color: var(--error); margin: 0; font-size: .9rem; }

.post-list, .comment-list { list-style: none; padding: 0; margin: 0 0 24px; }
.post-list li a {
  display: block;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 14px 18px;
  margin-bottom: 10px;
  color: var(--text);
}
.post-list li a:hover { border-color: var(--accent); text-decoration: none; }
.post-title { font-weight: 600; display: block; }
.excerpt { color: var(--muted); font-size: .9rem; display: block; overflow-wrap: anywhere; }
.meta { color: var(--muted); font-size: .85rem; margin: 0; }
.body { white-space: pre-wrap; overflow-wrap: anywhere; margin-top: 12px; }
.empty { color: var(--muted); text-align: center; padding: 24px 0; }

.comment-list li {
  border-left: 3px solid var(--border);
  padding: 4px 0 4px 14px;
  margin-bottom: 14px;
}
.comment-list .body { margin-top: 2px; }

.pager { display: flex; justify-content: space-between; }
.btn-secondary { cursor: pointer; }