:root {
  --bg: #111418;
  --surface: #181d22;
  --surface-strong: #20272e;
  --text: #f4f7f8;
  --text-muted: #b7c0c7;
  --line: rgba(255, 255, 255, 0.14);
  --accent: #4fd1c5;
  --accent-warm: #ffb26b;
  --max: 1120px;
}

* {
  box-sizing: border-box;
}

html {
  min-width: 320px;
}

body {
  margin: 0;
  color: var(--text);
  background: var(--bg);
  font-family: "Helvetica Neue", Arial, "Hiragino Kaku Gothic ProN", "Hiragino Sans", Meiryo, sans-serif;
  line-height: 1.7;
}

main {
  min-height: calc(100svh - 64px);
}

a {
  color: inherit;
  text-decoration: none;
}

img {
  max-width: 100%;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 64px;
  padding: 0.85rem clamp(1rem, 4vw, 2rem);
  background: rgba(17, 20, 24, 0.88);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(16px);
}

.brand {
  font-weight: 800;
  letter-spacing: 0;
}

.nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  justify-content: flex-end;
}

.nav a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 40px;
  padding: 0 0.85rem;
  border-radius: 6px;
  color: var(--text-muted);
  font-size: 0.95rem;
}

.nav a:hover {
  color: var(--text);
  background: rgba(255, 255, 255, 0.08);
}

.eyebrow {
  margin: 0 0 0.6rem;
  color: var(--accent);
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.section {
  background: var(--surface);
}

.section__inner {
  width: min(100%, var(--max));
  margin: 0 auto;
  padding: clamp(3rem, 7vw, 5rem) clamp(1rem, 4vw, 2rem);
}

.intro {
  max-width: 760px;
}

.intro h1,
.intro h2 {
  margin: 0;
  font-size: clamp(1.75rem, 4vw, 2.6rem);
  line-height: 1.25;
  letter-spacing: 0;
}

.intro p {
  margin: 1rem 0 0;
  color: var(--text-muted);
}

.site-footer {
  border-top: 1px solid var(--line);
  padding: 1rem clamp(1rem, 4vw, 2rem) 2rem;
  color: var(--text-muted);
  font-size: 0.9rem;
}

.site-footer p {
  width: min(100%, var(--max));
  margin: 0 auto;
}