@charset "UTF-8";

/* ==========================================================================
   Reset / base
   ========================================================================== */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: "Noto Sans JP", "Hiragino Kaku Gothic ProN", "Hiragino Sans", Meiryo, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; height: auto; display: block; }
a { color: inherit; text-decoration: none; }
ul { list-style: none; margin: 0; padding: 0; }
h1, h2, h3, h4, h5, h6 { margin: 0; font-weight: 700; line-height: 1.5; }
p { margin: 0 0 1em; }
p:last-child { margin-bottom: 0; }

:root {
  --navy: #17324f;
  --navy-deep: #0e2138;
  --gold: #c99a3f;
  --gold-light: #f1d99a;
  --teal: #2f7d78;
  --bg: #f6f7f9;
  --surface: #ffffff;
  --text: #232a33;
  --text-soft: #5b6673;
  --border: #e4e7ec;
  --radius-lg: 20px;
  --radius-md: 14px;
  --radius-sm: 8px;
  --shadow: 0 8px 30px rgba(23, 50, 79, 0.08);
  --shadow-sm: 0 2px 10px rgba(23, 50, 79, 0.06);
  --container: 1100px;
}

.container {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
}

.section { padding: 56px 0; }

/* ==========================================================================
   Header
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.94);
  backdrop-filter: saturate(180%) blur(10px);
  border-bottom: 1px solid var(--border);
}
.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding-top: 12px;
  padding-bottom: 12px;
}
.brand { display: flex; flex-direction: column; min-width: 0; }
.brand-name {
  font-weight: 700;
  color: var(--navy);
  font-size: clamp(0.85rem, 0.7rem + 0.6vw, 1.05rem);
  white-space: nowrap;
}
.brand-sub { font-size: 0.72rem; color: var(--text-soft); }
.header-nav { display: none; gap: 18px; }
.header-nav a { font-size: 0.84rem; font-weight: 700; color: var(--text-soft); white-space: nowrap; }
.header-nav a.active, .header-nav a:hover { color: var(--navy); }

/* ==========================================================================
   Buttons
   ========================================================================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 13px 28px;
  border-radius: 999px;
  font-weight: 700;
  font-size: 0.95rem;
  white-space: nowrap;
  transition: transform 0.15s ease, box-shadow 0.15s ease, background 0.15s ease;
  border: 2px solid transparent;
}
.btn-primary {
  background: linear-gradient(135deg, var(--gold) 0%, #b8842a 100%);
  color: #fff;
  box-shadow: 0 10px 24px rgba(201, 154, 63, 0.35);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 14px 28px rgba(201, 154, 63, 0.42); }
.btn-outline { background: transparent; color: var(--navy); border-color: var(--navy); }
.btn-outline:hover { background: var(--navy); color: #fff; }
.btn-sm { padding: 9px 18px; font-size: 0.85rem; }
.btn-block { width: 100%; }

/* ==========================================================================
   Hero
   ========================================================================== */
.hero {
  position: relative;
  background: radial-gradient(ellipse at top right, #1f4c6e 0%, var(--navy) 45%, var(--navy-deep) 100%);
  color: #fff;
  overflow: hidden;
}
.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    radial-gradient(circle at 12% 20%, rgba(201, 154, 63, 0.22), transparent 40%),
    radial-gradient(circle at 88% 82%, rgba(47, 125, 120, 0.28), transparent 45%);
  pointer-events: none;
}
.hero .container { position: relative; padding: 36px 24px; }
.hero-banner-img { border-radius: var(--radius-md); box-shadow: var(--shadow); overflow: hidden; margin-bottom: 18px; }
.hero h1 { font-size: clamp(1.2rem, 1rem + 1vw, 1.7rem); letter-spacing: 0.02em; margin-bottom: 8px; }
.hero-lead { font-size: 0.92rem; color: rgba(255, 255, 255, 0.85); max-width: 620px; }

/* ==========================================================================
   Layout: content + sidebar
   ========================================================================== */
.layout { display: grid; grid-template-columns: minmax(0, 1fr); gap: 32px; align-items: start; }

/* ==========================================================================
   Article content card
   ========================================================================== */
.content-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  padding: 32px;
}
.content-card h3.heading {
  color: var(--navy);
  font-size: 1.1rem;
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--border);
}
.article-body p { margin-bottom: 1em; color: var(--text); }
.article-body img { border-radius: var(--radius-sm); }
.article-body hr { border: 0; border-top: 1px solid var(--border); margin: 20px 0; }
.article-body h3.heading:not(:first-child) { margin-top: 28px; }
.article-body h4 {
  color: var(--navy);
  font-size: 0.95rem;
  margin: 20px 0 10px;
}
.article-body strong { color: var(--navy); }
.article-body .related-articles,
.article-body ul {
  display: flex;
  flex-direction: column;
  gap: 6px;
  margin-bottom: 1em;
}
.article-body ul li { font-size: 0.92rem; color: var(--text-soft); }
.article-body ul li a { color: var(--navy); font-weight: 500; }
.article-body ul li a:hover { color: var(--gold); text-decoration: underline; }
.article-body table {
  width: 100%;
  border-collapse: collapse;
  margin: 16px 0;
  font-size: 0.88rem;
}
.article-body table th, .article-body table td {
  padding: 8px 10px;
  border: 1px solid var(--border);
  text-align: left;
}
.article-body table th { background: var(--navy); color: #fff; font-weight: 700; }
.article-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
  padding-top: 24px;
  border-top: 1px solid var(--border);
}

/* ==========================================================================
   Index page: article list
   ========================================================================== */
.article-list { display: flex; flex-direction: column; gap: 2px; }
.article-list li {
  padding: 10px 0;
  border-bottom: 1px solid var(--border);
  font-size: 0.9rem;
  color: var(--text-soft);
}
.article-list li:last-child { border-bottom: 0; }
.article-list a { color: var(--navy); font-weight: 500; }
.article-list a:hover { color: var(--gold); text-decoration: underline; }
.article-list .num { color: var(--gold); font-weight: 700; margin-right: 6px; }

/* ==========================================================================
   Sidebar
   ========================================================================== */
.sidebar { display: flex; flex-direction: column; gap: 20px; }
.sidebar-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 22px;
  box-shadow: var(--shadow-sm);
}
.sidebar-card h3 {
  font-size: 0.95rem;
  color: var(--navy);
  margin-bottom: 14px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--border);
}
.sidebar-card ul { display: flex; flex-direction: column; gap: 8px; }
.sidebar-card li { font-size: 0.86rem; color: var(--text-soft); }
.sidebar-card li a { color: var(--navy); font-weight: 500; }
.sidebar-card li a:hover { color: var(--gold); }
.sidebar-card .updated { font-size: 0.76rem; color: var(--text-soft); text-align: right; margin-top: 8px; }

/* ==========================================================================
   Footer
   ========================================================================== */
.site-footer {
  background: var(--navy-deep);
  color: rgba(255, 255, 255, 0.82);
  padding: 48px 0 24px;
  margin-top: 40px;
}
.footer-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 32px;
  padding-bottom: 28px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.12);
}
.footer-grid h4 { color: #fff; font-size: 0.95rem; margin-bottom: 10px; }
.footer-grid p { font-size: 0.86rem; margin: 0; }
.footer-grid a:hover { color: var(--gold-light); }
.footer-links { display: flex; flex-direction: column; gap: 8px; }
.footer-bottom { padding-top: 18px; text-align: center; font-size: 0.8rem; color: rgba(255, 255, 255, 0.55); }
.footer-disclaimer { font-size: 0.74rem; color: rgba(255, 255, 255, 0.5); margin-top: 10px; }

/* ==========================================================================
   Back to top
   ========================================================================== */
#pagetop { position: fixed; bottom: 22px; right: 22px; z-index: 200; }
#pagetop a {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--navy);
  color: #fff;
  font-size: 0.75rem;
  font-weight: 700;
  box-shadow: var(--shadow);
  transition: background 0.15s ease, transform 0.15s ease;
}
#pagetop a:hover { background: var(--gold); transform: translateY(-3px); }

/* ==========================================================================
   Responsive
   ========================================================================== */
@media screen and (min-width: 720px) {
  .header-nav { display: flex; }
  .layout { grid-template-columns: minmax(0, 1fr) 300px; }
}
@media screen and (max-width: 760px) {
  .section { padding: 40px 0; }
  .content-card { padding: 22px; }
  .article-body table { font-size: 0.8rem; }
}