:root {
  --bg: #0b0d10;
  --panel: #12161b;
  --panel-2: #171c22;
  --text: #eef2f5;
  --muted: #a7b0b9;
  --line: #2a323b;
  --accent: #d7dde3;
  --header-bg: rgba(11,13,16,.92);
  --button-text: #0b0d10;
  --max: 1080px;
  color-scheme: dark;
}

:root[data-theme="light"] {
  --bg: #f6f7f8;
  --panel: #ffffff;
  --panel-2: #eef1f3;
  --text: #171a1d;
  --muted: #5f6871;
  --line: #d8dde2;
  --accent: #1f252b;
  --header-bg: rgba(246,247,248,.92);
  --button-text: #ffffff;
  color-scheme: light;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans JP", "Hiragino Kaku Gothic ProN", "Yu Gothic", sans-serif;
  line-height: 1.65;
  transition: background-color .18s ease, color .18s ease;
}

a { color: inherit; }
button { font: inherit; }
.wrap { width: min(var(--max), calc(100% - 40px)); margin: 0 auto; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  border-bottom: 1px solid var(--line);
  background: var(--header-bg);
  backdrop-filter: blur(10px);
}

.nav {
  min-height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}
.brand { text-decoration: none; font-weight: 700; letter-spacing: .02em; }
.nav-right { display: flex; align-items: center; gap: 12px; }
nav { display: flex; gap: 22px; flex-wrap: wrap; }
nav a { text-decoration: none; color: var(--muted); font-size: .95rem; }
nav a:hover { color: var(--text); }
.language-switch,
.theme-toggle {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 4px;
  border: 1px solid var(--line);
  background: var(--panel);
  white-space: nowrap;
}
.language-switch a,
.language-switch span {
  padding: 5px 9px;
  text-decoration: none;
  font-size: .82rem;
  font-weight: 700;
  color: var(--muted);
}
.language-switch .active { background: var(--accent); color: var(--button-text); }
.language-switch a:hover { color: var(--text); }
.theme-toggle {
  cursor: pointer;
  color: var(--text);
  min-width: 42px;
  justify-content: center;
  padding: 8px 10px;
}
.theme-toggle:hover { border-color: var(--muted); }
.theme-toggle:focus-visible { outline: 2px solid var(--text); outline-offset: 2px; }
.theme-icon { line-height: 1; font-size: 1rem; }

.hero { padding: 112px 0 96px; }
.eyebrow, .section-kicker {
  margin: 0 0 14px;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: .14em;
  font-size: .78rem;
  font-weight: 700;
}
.hero h1 {
  margin: 0;
  max-width: 900px;
  font-size: clamp(3rem, 8vw, 6.8rem);
  line-height: .98;
  letter-spacing: -.045em;
}
html[lang="ja"] .hero h1 { line-height: 1.08; letter-spacing: -.035em; }
.lede {
  max-width: 760px;
  margin: 28px 0 0;
  color: var(--muted);
  font-size: clamp(1.08rem, 2vw, 1.3rem);
}
.actions { display: flex; align-items: center; gap: 18px; flex-wrap: wrap; margin-top: 30px; }
.actions.compact { margin-top: 14px; }
.button {
  display: inline-block;
  text-decoration: none;
  padding: 12px 18px;
  border: 1px solid var(--accent);
  background: var(--accent);
  color: var(--button-text);
  font-weight: 700;
}
.button.secondary { background: transparent; color: var(--text); border-color: var(--line); }
.text-link { color: var(--text); text-underline-offset: 4px; }
.report-language-block { margin-top: 28px; padding-top: 22px; border-top: 1px solid var(--line); }

.section { padding: 84px 0; border-top: 1px solid var(--line); }
.section h2 { margin: 0 0 20px; font-size: clamp(2rem, 4vw, 3.2rem); letter-spacing: -.03em; }
.section > p:not(.section-kicker) { max-width: 780px; color: var(--muted); }

.case-card {
  background: linear-gradient(180deg, var(--panel-2), var(--panel));
  border: 1px solid var(--line);
  padding: 32px;
}
.case-meta { display: flex; flex-wrap: wrap; gap: 10px 16px; color: var(--muted); font-size: .84rem; }
.case-meta span:not(:last-child)::after { content: "·"; margin-left: 16px; }
.case-card h2 { margin-top: 18px; }
.case-subtitle { max-width: 820px; color: var(--text) !important; font-size: 1.08rem; }

.grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  margin: 28px 0;
}
.grid > div { background: var(--panel); padding: 22px; }
.grid strong { display: block; margin-bottom: 8px; }
.grid span { color: var(--muted); }
.principle { color: var(--text) !important; font-size: 1.08rem; }

.footer {
  border-top: 1px solid var(--line);
  padding: 34px 0 60px;
  color: var(--muted);
  font-size: .88rem;
}
.footer p { margin: 6px 0; }

@media (max-width: 820px) {
  .nav { align-items: flex-start; flex-direction: column; padding: 16px 0; }
  .nav-right { width: 100%; align-items: flex-start; flex-direction: column; gap: 12px; }
  nav { gap: 14px; }
  .hero { padding: 80px 0 68px; }
  .section { padding: 64px 0; }
  .grid { grid-template-columns: 1fr; }
  .case-card { padding: 24px; }
  .case-meta span::after { display: none; }
}