:root {
  color: #333;
  background: #fff;
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Yu Gothic", sans-serif;
  line-height: 1.8;
}

* { box-sizing: border-box; }
body { margin: 0; }
a { color: inherit; }

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 80px;
  padding: 0 5%;
  border-bottom: 1px solid #eee;
}

.site-logo { color: #eb6100; font-weight: 800; text-decoration: none; }
.site-header nav { display: flex; gap: 24px; font-size: .9rem; }
.site-header nav a { text-decoration: none; }

.blog-hero { padding: 90px 5%; background: #fff8f1; text-align: center; }
.blog-hero > p { margin: 0; color: #eb6100; font-size: .8rem; font-weight: bold; letter-spacing: .15em; }
.blog-hero h1 { margin: 12px 0 20px; color: #eb6100; font-size: clamp(2rem, 5vw, 3.5rem); }
.blog-hero div { max-width: 680px; margin: auto; }

.post-list, .post-detail { width: min(90%, 900px); margin: 0 auto; padding: 80px 0; }
.post-card { padding: 30px 0; border-bottom: 1px solid #e5e5e5; }
.post-card time, .post-date { color: #777; font-size: .85rem; }
.post-card h2 { margin: 8px 0; font-size: 1.45rem; }
.post-card h2 a { text-decoration: none; }
.post-card p { margin: 0 0 15px; }
.read-more, .back-to-list a { color: #d65300; font-weight: bold; }
.empty-message { text-align: center; }

.post-detail { max-width: 760px; }
.post-detail h1 { margin: 8px 0 20px; color: #eb6100; font-size: clamp(1.9rem, 4vw, 3rem); line-height: 1.4; }
.post-categories span { display: inline-block; margin-right: 8px; padding: 2px 10px; background: #fff0e5; color: #d65300; font-size: .82rem; }
.post-body { margin-top: 45px; }
.post-body h2 { margin-top: 50px; color: #eb6100; }
.post-body img { max-width: 100%; height: auto; }
.back-to-list { margin-top: 70px; }

.site-footer { padding: 45px 5%; background: #f6f6f6; text-align: center; }
.site-footer a, .site-footer small { display: block; margin: 8px 0; color: #666; font-size: .85rem; }

@media (max-width: 640px) {
  .site-header { min-height: 70px; padding: 0 5%; }
  .site-header nav { gap: 12px; font-size: .78rem; }
  .blog-hero { padding: 65px 5%; }
  .post-list, .post-detail { padding: 55px 0; }
}