* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --bg-0: #020617;
  --bg-1: #0f172a;
  --text: #e5e7eb;
  --muted: #cbd5f5;
  --muted-2: #94a3b8;
  --accent: #38bdf8;
  --surface: rgba(255, 255, 255, 0.04);
  --border: rgba(148, 163, 184, 0.22);
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: "Helvetica Neue", Arial, "Hiragino Kaku Gothic ProN",
    "Noto Sans JP", sans-serif;
  background: linear-gradient(180deg, var(--bg-1), var(--bg-0));
  color: var(--text);
  line-height: 1.7;
  min-height: 100vh;
}

.container {
  max-width: 960px;
  margin: 0 auto;
  padding: 0 24px;
}

.skip-link {
  position: absolute;
  left: 12px;
  top: 12px;
  padding: 10px 14px;
  border-radius: 10px;
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text);
  text-decoration: none;
  transform: translateY(-160%);
  transition: transform 0.2s ease;
  z-index: 10;
}

.skip-link:focus-visible {
  transform: translateY(0);
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}

.site-header {
  border-bottom: 1px solid rgba(148, 163, 184, 0.16);
  background: rgba(2, 6, 23, 0.35);
}

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 22px 24px;
}

.brand {
  display: flex;
  align-items: center;
}

.brand__logo {
  height: 40px;
  width: auto;
  display: block;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.site-nav a {
  color: var(--muted);
  text-decoration: none;
  font-weight: 600;
}

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

.site-nav a:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 4px;
  border-radius: 10px;
}

.hero {
  padding: 72px 0 84px;
}

.hero h1 {
  font-size: clamp(2rem, 5vw, 3.2rem);
  font-weight: 800;
  letter-spacing: 0.02em;
  margin-bottom: 32px;
  text-wrap: balance;
}

.lead {
  font-size: 1.1rem;
  color: var(--muted);
  margin-bottom: 40px;
  max-width: 56ch;
}

.highlight {
  color: var(--accent);
  font-weight: 700;
}

.invite-note {
  margin-top: 18px;
  padding: 14px 16px;
  max-width: 72ch;
  border-radius: 16px;
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid rgba(148, 163, 184, 0.18);
}

.invite-note p {
  color: var(--muted);
  margin-top: 10px;
}

.pill {
  display: inline-flex;
  align-items: center;
  padding: 6px 12px;
  border-radius: 999px;
  background: rgba(56, 189, 248, 0.14);
  border: 1px solid rgba(56, 189, 248, 0.35);
  color: var(--text);
  font-weight: 700;
  letter-spacing: 0.02em;
}

.emphasis {
  font-weight: 800;
  letter-spacing: 0.02em;
}

.flow {
  margin: 0 0 96px;
}

.flow h2 {
  font-size: 1.8rem;
  margin-bottom: 14px;
}

.section-lead {
  color: var(--muted);
  margin-bottom: 18px;
  max-width: 72ch;
}

.flow-diagram {
  padding: 26px;
  border-radius: 20px;
  background: var(--surface);
  border: 1px solid var(--border);
  display: grid;
  grid-template-columns: 1fr 60px 1fr 60px 1fr;
  grid-template-rows: auto auto;
  gap: 16px;
  align-items: center;
}

.flow-card {
  padding: 18px 16px;
  border-radius: 16px;
  border: 1px solid rgba(148, 163, 184, 0.2);
  background: rgba(2, 6, 23, 0.25);
  position: relative;
  min-height: 92px;
}

.flow-title {
  font-weight: 800;
  letter-spacing: 0.02em;
}

.flow-caption {
  color: var(--muted);
  margin-top: 6px;
  font-size: 0.95rem;
}

.flow-badge {
  position: absolute;
  right: 12px;
  top: 12px;
  padding: 6px 10px;
  border-radius: 999px;
  background: rgba(56, 189, 248, 0.12);
  border: 1px solid rgba(56, 189, 248, 0.32);
  color: var(--text);
  font-weight: 800;
  font-size: 0.9rem;
}

.flow-arrow {
  text-align: center;
  font-size: 1.5rem;
  color: rgba(229, 231, 235, 0.85);
}

.flow-card--supporter {
  grid-column: 1;
  grid-row: 1 / span 2;
}

.flow-card--trypass {
  grid-column: 3;
  grid-row: 1 / span 2;
}

.flow-card--challenger {
  grid-column: 5;
  grid-row: 1;
}

.flow-card--org {
  grid-column: 5;
  grid-row: 2;
}

.flow-arrow--to-trypass {
  grid-column: 2;
  grid-row: 1 / span 2;
}

.flow-arrow--to-challenger {
  grid-column: 4;
  grid-row: 1;
}

.flow-arrow--to-org {
  grid-column: 4;
  grid-row: 2;
}

.flow-footnote {
  margin-top: 14px;
  color: var(--muted-2);
  font-size: 0.95rem;
}

.about {
  margin: 0 0 96px;
  padding: 40px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 20px;
}

.about h2 {
  font-size: 1.8rem;
  margin-bottom: 24px;
}

.about p {
  margin-bottom: 16px;
  color: #dbeafe;
  max-width: 68ch;
}

.footer {
  text-align: center;
  font-size: 0.9rem;
  color: var(--muted-2);
  padding: 36px 0 52px;
  border-top: 1px solid rgba(148, 163, 184, 0.16);
}

.footer__inner {
  padding: 0 24px;
}

@media (max-width: 640px) {
  .site-header__inner {
    padding: 18px 24px;
    gap: 10px;
  }

  .brand__logo {
    height: 34px;
  }

  .hero {
    padding: 56px 0 68px;
  }

  .flow-diagram {
    grid-template-columns: 1fr;
    grid-template-rows: auto;
  }

  .flow-card--supporter,
  .flow-card--trypass,
  .flow-card--challenger,
  .flow-card--org,
  .flow-arrow--to-trypass,
  .flow-arrow--to-challenger,
  .flow-arrow--to-org {
    grid-column: auto;
    grid-row: auto;
  }

  .flow-arrow {
    transform: rotate(90deg);
  }

  .about {
    padding: 26px;
    border-radius: 16px;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
  }
}