*, *::before, *::after { box-sizing: border-box; }

:root {
  --accent: #1e4d82;
  --accent2: #2f7a55;
  --bg: #ffffff;
  --bg2: #f3f7f3;
  --text: #1a2d3d;
  --muted: #5a7280;
  --line: rgba(26, 45, 61, .12);
}

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: 'Noto Sans JP', sans-serif;
  color: var(--text);
  background:
    linear-gradient(180deg, rgba(243,247,243,.92), rgba(255,255,255,.98) 360px),
    var(--bg);
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

a { color: inherit; }
img { display: block; max-width: 100%; height: auto; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 18px;
  padding: 14px clamp(18px, 5vw, 60px);
  background: rgba(255,255,255,.93);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid rgba(0,0,0,.07);
}

.nav-logo {
  color: var(--accent);
  text-decoration: none;
  font-size: .98rem;
  font-weight: 700;
  line-height: 1.25;
  letter-spacing: .04em;
  flex: 0 1 auto;
}

.nav-logo span {
  display: block;
  font-family: 'Rajdhani', sans-serif;
  font-size: .68rem;
  font-weight: 600;
  letter-spacing: .2em;
  color: var(--accent2);
  text-transform: uppercase;
}

.site-nav {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: clamp(12px, 3vw, 30px);
  flex-wrap: wrap;
}

.site-nav a {
  color: var(--muted);
  text-decoration: none;
  font-size: .8rem;
  font-weight: 500;
  letter-spacing: .06em;
}

.site-nav a:hover { color: var(--accent); }

.site-nav .nav-cta {
  padding: 8px 18px;
  border: 1px solid var(--accent);
  border-radius: 2px;
  color: var(--accent);
}

main {
  width: min(100%, 960px);
  margin: 0 auto;
  padding: 0 clamp(18px, 5vw, 32px) 80px;
}

.blog-hero {
  padding: clamp(58px, 12vw, 110px) 0 34px;
}

.eyebrow {
  width: fit-content;
  margin: 0 0 18px;
  padding: 5px 13px;
  border: 1px solid rgba(47,122,85,.25);
  color: var(--accent2);
  background: rgba(47,122,85,.06);
  font-size: .68rem;
  letter-spacing: .24em;
}

.blog-hero h1,
.article-header h1 {
  margin: 0;
  font-size: clamp(2rem, 7vw, 3.6rem);
  line-height: 1.25;
  letter-spacing: 0;
}

.blog-hero p:last-child,
.article-header p {
  max-width: 680px;
  margin: 18px 0 0;
  color: var(--muted);
  font-size: clamp(1rem, 2.5vw, 1.08rem);
  line-height: 1.9;
}

.post-list {
  display: grid;
  gap: 18px;
  padding-top: 18px;
}

.post-card {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(255,255,255,.82);
  transition: transform .2s, border-color .2s, box-shadow .2s;
}

.post-card:hover {
  transform: translateY(-2px);
  border-color: rgba(30,77,130,.35);
  box-shadow: 0 16px 42px rgba(30,77,130,.08);
}

.post-card a {
  display: block;
  text-decoration: none;
}

.post-card-body {
  padding: clamp(20px, 5vw, 30px);
}

.post-card-image {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  border-radius: 8px 8px 0 0;
  border-bottom: 1px solid var(--line);
}

.post-card h2 {
  margin: 12px 0 10px;
  color: var(--text);
  font-size: clamp(1.25rem, 4.2vw, 1.7rem);
  line-height: 1.45;
  letter-spacing: 0;
}

.post-card p {
  margin: 0;
  color: var(--muted);
  line-height: 1.85;
}

.post-meta {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
  color: var(--accent2);
  font-size: .78rem;
  letter-spacing: .08em;
}

.post-meta span {
  padding: 3px 9px;
  border: 1px solid rgba(47,122,85,.22);
  border-radius: 999px;
  background: rgba(47,122,85,.06);
}

.article {
  padding-top: clamp(40px, 10vw, 80px);
}

.back-link {
  display: inline-block;
  margin-bottom: 28px;
  color: var(--muted);
  font-size: .88rem;
  text-decoration: none;
}

.back-link:hover { color: var(--accent); }

.article-header {
  padding-bottom: 30px;
  border-bottom: 1px solid var(--line);
}

.article-cover {
  width: 100%;
  margin: 30px 0 0;
  border-radius: 8px;
  border: 1px solid var(--line);
  object-fit: cover;
}

.article-body {
  padding: 34px 0 18px;
  font-size: clamp(1rem, 2.7vw, 1.08rem);
  line-height: 2;
}

.article-body img {
  width: 100%;
  margin: 28px 0;
  border-radius: 8px;
}

.article-body h2 {
  margin: 42px 0 14px;
  padding-left: 14px;
  border-left: 3px solid var(--accent2);
  font-size: clamp(1.35rem, 4.8vw, 1.85rem);
  line-height: 1.45;
  letter-spacing: 0;
}

.article-body h3 {
  margin: 30px 0 10px;
  font-size: 1.2rem;
  letter-spacing: 0;
}

.article-body p,
.article-body ul {
  margin: 0 0 22px;
}

.article-body ul {
  padding-left: 1.2em;
}

.article-body li {
  margin: 8px 0;
}

.article-body a {
  color: var(--accent);
  text-underline-offset: 3px;
}

.related {
  padding-top: 24px;
  border-top: 1px solid var(--line);
}

.related h2 {
  margin: 0 0 14px;
  font-size: 1rem;
  color: var(--muted);
}

.related ul {
  margin: 0;
  padding-left: 1.1em;
}

.related li {
  margin: 8px 0;
}

.related a {
  color: var(--accent);
  text-decoration: none;
}

.site-footer {
  display: flex;
  justify-content: space-between;
  gap: 18px;
  align-items: center;
  padding: 30px clamp(18px, 5vw, 60px);
  border-top: 1px solid var(--line);
  background: var(--bg);
}

.site-footer strong {
  display: block;
  color: var(--accent);
  font-size: .95rem;
  letter-spacing: .04em;
}

.site-footer span,
.site-footer p {
  margin: 0;
  color: var(--muted);
  font-size: .72rem;
  line-height: 1.7;
}

@media (max-width: 640px) {
  .site-header {
    align-items: flex-start;
    padding: 12px 18px;
  }

  .site-nav {
    gap: 8px 12px;
  }

  .site-nav a {
    font-size: .74rem;
  }

  .site-nav a:first-child {
    display: none;
  }

  .site-nav .nav-cta {
    padding: 6px 12px;
  }

  .site-footer {
    flex-direction: column;
    align-items: flex-start;
  }
}