:root {
  --color-primary: #2563EB;
  --color-secondary: #4F46E5;
  --color-bg: #FFFFFF;
  --color-text: #111827;
  --color-muted: #6B7280;
  --color-surface: #F3F4F6;
  --color-border: #E5E7EB;
  --gradient-brand: linear-gradient(135deg, var(--color-primary), var(--color-secondary));

  --font-sans: 'Inter', 'Noto Sans JP', -apple-system, BlinkMacSystemFont, 'Hiragino Sans', 'Yu Gothic', sans-serif;

  --header-height: 76px;
  --container-width: 1120px;
  --radius-sm: 10px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --shadow-sm: 0 1px 2px rgba(17, 24, 39, 0.06), 0 1px 3px rgba(17, 24, 39, 0.06);
  --shadow-md: 0 8px 24px rgba(17, 24, 39, 0.08);
  --shadow-lg: 0 20px 48px rgba(17, 24, 39, 0.12);
  --ease: cubic-bezier(0.16, 1, 0.3, 1);
}

* { box-sizing: border-box; }
html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--header-height);
}
body {
  margin: 0;
  font-family: var(--font-sans);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; margin: 0; padding: 0; }
h1, h2, h3, p { margin: 0; }
button { font: inherit; cursor: pointer; }

.container {
  width: 100%;
  max-width: var(--container-width);
  margin-inline: auto;
  padding-inline: 24px;
}

.skip-link {
  position: absolute;
  left: 16px;
  top: -60px;
  background: var(--color-primary);
  color: #fff;
  padding: 10px 18px;
  border-radius: var(--radius-sm);
  z-index: 1000;
  transition: top 0.2s var(--ease);
  font-weight: 600;
}
.skip-link:focus { top: 16px; }

:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 3px;
}

/* Header */
.site-header {
  position: fixed;
  inset: 0 0 auto 0;
  height: var(--header-height);
  display: flex;
  align-items: center;
  z-index: 100;
  background: rgba(255, 255, 255, 0.7);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  transition: background 0.3s var(--ease), box-shadow 0.3s var(--ease), border-color 0.3s var(--ease);
  border-bottom: 1px solid transparent;
}
.site-header.is-scrolled {
  background: rgba(255, 255, 255, 0.92);
  border-bottom-color: var(--color-border);
  box-shadow: var(--shadow-sm);
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}
.brand { display: flex; align-items: center; }
.brand-logo { height: 28px; width: auto; }

.nav-links {
  display: flex;
  align-items: center;
  gap: 8px;
}
.nav-link {
  display: inline-block;
  padding: 10px 16px;
  border-radius: 999px;
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--color-text);
  transition: background 0.2s var(--ease), color 0.2s var(--ease);
}
.nav-link:hover { background: var(--color-surface); }
.nav-link.is-active { color: var(--color-primary); }
.nav-link-cta {
  background: var(--gradient-brand);
  color: #fff !important;
}
.nav-link-cta:hover { opacity: 0.92; background: var(--gradient-brand); }

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  width: 40px;
  height: 40px;
  background: transparent;
  border: none;
  border-radius: var(--radius-sm);
}
.nav-toggle:hover { background: var(--color-surface); }
.nav-toggle-bar {
  width: 20px;
  height: 2px;
  background: var(--color-text);
  border-radius: 2px;
  transition: transform 0.25s var(--ease), opacity 0.25s var(--ease);
}
.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* Hero */
.hero {
  position: relative;
  min-height: 100svh;
  display: flex;
  align-items: center;
  padding-top: var(--header-height);
  background: var(--gradient-brand);
  overflow: hidden;
  isolation: isolate;
}
.hero-bg {
  position: absolute;
  inset: 0;
  overflow: hidden;
}
.hero-watermark {
  position: absolute;
  top: 50%;
  right: -10%;
  width: 900px;
  max-width: 90vw;
  transform: translateY(-50%) rotate(-6deg);
  opacity: 0.16;
  mix-blend-mode: multiply;
  filter: saturate(0);
  pointer-events: none;
}
.hero-inner {
  position: relative;
  z-index: 1;
  padding-block: 96px;
}
.hero-kicker {
  color: rgba(255, 255, 255, 0.85);
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  font-size: 0.8rem;
  margin-bottom: 20px;
}
.hero-title {
  font-size: clamp(2.75rem, 7vw, 5.25rem);
  font-weight: 800;
  color: #fff;
  letter-spacing: -0.02em;
  line-height: 1.05;
}
.hero-subtitle {
  margin-top: 20px;
  font-size: clamp(1.1rem, 2.4vw, 1.5rem);
  color: rgba(255, 255, 255, 0.92);
  font-weight: 500;
}
.hero-badge {
  margin-top: 28px;
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 8px 18px;
  border: 1px solid rgba(255, 255, 255, 0.35);
  border-radius: 999px;
  color: #fff;
  font-size: 0.85rem;
  font-weight: 600;
  background: rgba(255, 255, 255, 0.08);
}
.hero-badge .dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: #fff;
}
.hero-actions {
  margin-top: 44px;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 28px;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 15px 28px;
  border-radius: 999px;
  font-weight: 700;
  font-size: 0.98rem;
  transition: transform 0.25s var(--ease), box-shadow 0.25s var(--ease), opacity 0.25s var(--ease);
}
.btn-primary {
  background: #fff;
  color: var(--color-primary);
  box-shadow: var(--shadow-md);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: var(--shadow-lg); }
.btn-primary svg { transition: transform 0.25s var(--ease); }
.btn-primary:hover svg { transform: translateY(2px); }
.btn-ghost-inverse {
  color: #fff;
  font-weight: 600;
  border-bottom: 1px solid rgba(255, 255, 255, 0.5);
  border-radius: 0;
  padding: 4px 2px;
}
.btn-ghost-inverse:hover { border-color: #fff; }

/* Sections */
.section { padding-block: 120px; }
.section-surface { background: var(--color-surface); }
.section-head { max-width: 640px; margin-bottom: 64px; }
.eyebrow {
  display: inline-block;
  color: var(--color-primary);
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  font-size: 0.8rem;
  margin-bottom: 14px;
}
.section-head h2 {
  font-size: clamp(1.75rem, 3.5vw, 2.5rem);
  font-weight: 800;
  letter-spacing: -0.01em;
}
.section-lead {
  margin-top: 16px;
  color: var(--color-muted);
  font-size: 1.05rem;
}
.br-desktop { display: none; }
@media (min-width: 720px) { .br-desktop { display: inline; } }

/* About pillars */
.pillars {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 24px;
}
.pillar-card {
  padding: 32px;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease);
}
.pillar-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); }
.pillar-icon {
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  background: var(--gradient-brand);
  color: #fff;
  margin-bottom: 20px;
}
.pillar-card h3 { font-size: 1.15rem; font-weight: 700; margin-bottom: 10px; }
.pillar-card p { color: var(--color-muted); font-size: 0.95rem; }

/* Members */
.members {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 20px;
}
.member-card {
  text-align: center;
  padding: 32px 20px;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease);
}
.member-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); }
.member-avatar {
  width: 64px;
  height: 64px;
  margin: 0 auto 18px;
  border-radius: 50%;
  background: var(--gradient-brand);
  color: #fff;
  font-weight: 800;
  font-size: 1.4rem;
  display: flex;
  align-items: center;
  justify-content: center;
}
.member-name { font-size: 1.05rem; font-weight: 700; }
.member-role { margin-top: 6px; color: var(--color-muted); font-size: 0.9rem; }
.member-card-open { background: transparent; border-style: dashed; }
.member-avatar-open {
  background: var(--color-bg);
  border: 1.5px dashed var(--color-muted);
  color: var(--color-muted);
  font-size: 1.6rem;
}
.members-note {
  margin-top: 40px;
  text-align: center;
  color: var(--color-muted);
  font-size: 0.95rem;
}
.members-note a { color: var(--color-primary); font-weight: 600; }
.members-note a:hover { text-decoration: underline; }

/* Projects */
.projects {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 24px;
}
.project-card {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
  background: var(--color-bg);
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease);
}
.project-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); }
.project-media {
  aspect-ratio: 16 / 11;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 32px;
}
.project-media img { width: 100%; height: 100%; object-fit: contain; }
.project-media-dark { background: #0a0a0a; }
.project-media-light { background: #fbfbfc; }
.project-media-soon {
  background: var(--color-surface);
  color: var(--color-muted);
}
.project-body { padding: 24px; }
.project-body h3 { font-size: 1.2rem; font-weight: 700; }
.project-body p { margin-top: 6px; color: var(--color-muted); font-size: 0.95rem; }
.project-note { margin-top: 10px !important; font-size: 0.85rem !important; }
.badge {
  display: inline-block;
  margin-top: 16px;
  padding: 6px 14px;
  border-radius: 999px;
  background: rgba(37, 99, 235, 0.1);
  color: var(--color-primary);
  font-size: 0.8rem;
  font-weight: 700;
}
.badge-muted { background: var(--color-border); color: var(--color-muted); }
.project-card-soon { border-style: dashed; }

/* News timeline */
.timeline {
  position: relative;
  max-width: 720px;
  padding-left: 32px;
}
.timeline::before {
  content: '';
  position: absolute;
  left: 5px;
  top: 6px;
  bottom: 6px;
  width: 2px;
  background: var(--color-border);
}
.timeline-item {
  position: relative;
  padding-bottom: 40px;
}
.timeline-item:last-child { padding-bottom: 0; }
.timeline-dot {
  position: absolute;
  left: -32px;
  top: 6px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--gradient-brand);
  box-shadow: 0 0 0 4px var(--color-bg);
}
.section-surface .timeline-dot { box-shadow: 0 0 0 4px var(--color-surface); }
.timeline-date {
  display: inline-block;
  font-weight: 700;
  color: var(--color-primary);
  font-size: 0.9rem;
  margin-bottom: 8px;
}
.timeline-content h3 { font-size: 1.1rem; font-weight: 700; }
.timeline-content p { margin-top: 6px; color: var(--color-muted); font-size: 0.95rem; }

/* Contact */
.contact-card {
  display: flex;
  align-items: center;
  gap: 18px;
  max-width: 520px;
  padding: 24px 28px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
}
.contact-icon {
  width: 48px;
  height: 48px;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  background: var(--gradient-brand);
  color: #fff;
}
.contact-email {
  flex: 1;
  min-width: 0;
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--color-text);
  overflow-wrap: break-word;
}
.contact-email:hover { color: var(--color-primary); }
.copy-btn {
  position: relative;
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 10px 16px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-bg);
  color: var(--color-muted);
  font-size: 0.85rem;
  font-weight: 600;
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease);
  flex-shrink: 0;
}
.copy-btn:hover { color: var(--color-primary); border-color: var(--color-primary); }
.copy-btn.is-copied { color: var(--color-primary); border-color: var(--color-primary); }
.copy-btn-label { white-space: nowrap; }

/* Footer */
.site-footer { background: var(--color-surface); border-top: 1px solid var(--color-border); }
.footer-inner {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 40px;
  padding-block: 56px;
}
.footer-logo { height: 24px; width: auto; margin-bottom: 16px; }
.footer-brand p { color: var(--color-muted); font-size: 0.9rem; }
.footer-brand p + p { margin-top: 6px; }
.footer-members { font-weight: 600; color: var(--color-text) !important; }
.footer-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 28px;
  align-content: flex-start;
}
.footer-nav a {
  color: var(--color-muted);
  font-size: 0.92rem;
  font-weight: 500;
  transition: color 0.2s var(--ease);
}
.footer-nav a:hover { color: var(--color-primary); }
.footer-bottom {
  border-top: 1px solid var(--color-border);
  padding-block: 24px;
}
.footer-bottom p {
  text-align: center;
  color: var(--color-muted);
  font-size: 0.85rem;
}

/* Scroll reveal */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.7s var(--ease), transform 0.7s var(--ease);
}
.reveal.is-visible { opacity: 1; transform: translateY(0); }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
  .btn, .pillar-card, .member-card, .project-card { transition: none; }
}

/* Responsive nav */
@media (max-width: 860px) {
  .nav-toggle { display: flex; }
  .nav { position: static; }
  .nav-links {
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 4px;
    background: #fff;
    border-bottom: 1px solid var(--color-border);
    padding: 12px;
    box-shadow: var(--shadow-md);
    transform: translateY(-8px);
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transition: transform 0.25s var(--ease), opacity 0.25s var(--ease), visibility 0.25s;
  }
  .nav-links.is-open {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
  }
  .nav-link { text-align: center; padding: 14px 16px; }
  .nav-link-cta { margin-top: 4px; }
}

@media (max-width: 640px) {
  .section { padding-block: 80px; }
  .hero-inner { padding-block: 64px; }
  .hero-actions { gap: 20px; }
}

@media (max-width: 480px) {
  .contact-card { flex-direction: column; align-items: flex-start; }
  .contact-email { font-size: 1.05rem; }
  .copy-btn { align-self: stretch; justify-content: center; }
}