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

:root {
  --black: #000000;
  --white: #ffffff;
  --gray-100: #f5f5f7;
  --gray-200: #e8e8ed;
  --gray-400: #86868b;
  --gray-600: #3a3a3c;
  --gray-800: #1d1d1f;
}

html { scroll-behavior: smooth; }

body {
  font-family: 'Noto Sans JP', sans-serif;
  background: var(--white);
  color: var(--black);
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

/* NAV */
nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(255,255,255,0.85);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid rgba(0,0,0,0.08);
  height: 52px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 24px;
}

.nav-logo {
  font-family: 'Noto Sans JP', sans-serif;
  font-weight: 400;
  font-size: 18px;
  letter-spacing: 0.05em;
  color: var(--black);
  text-decoration: none;
}

.nav-links {
  display: flex;
  gap: 32px;
  list-style: none;
}

.nav-links a {
  font-size: 13px;
  color: var(--gray-600);
  text-decoration: none;
  letter-spacing: 0.02em;
  transition: color 0.2s;
}
.nav-links a:hover { color: var(--black); }

.nav-cta {
  font-size: 13px;
  background: var(--black);
  color: var(--white);
  padding: 8px 20px;
  border-radius: 980px;
  text-decoration: none;
  letter-spacing: 0.02em;
  transition: background 0.2s;
}
.nav-cta:hover { background: var(--gray-600); }

/* HERO */
.hero {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 120px 24px 80px;
  background: var(--white);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse 80% 60% at 50% 50%, rgba(0,0,0,0.03) 0%, transparent 70%);
  pointer-events: none;
}

.hero-eyebrow {
  font-size: 13px;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--gray-400);
  margin-bottom: 24px;
  opacity: 0;
  animation: fadeUp 0.8s ease 0.1s forwards;
}

.hero-title {
  font-family: 'Noto Serif JP', serif;
  font-weight: 300;
  font-size: clamp(48px, 8vw, 96px);
  line-height: 1.1;
  letter-spacing: -0.02em;
  color: var(--black);
  margin-bottom: 28px;
  opacity: 0;
  animation: fadeUp 0.8s ease 0.25s forwards;
}

.hero-title span {
  display: block;
  font-weight: 700;
  font-family: 'Noto Sans JP', sans-serif;
  letter-spacing: -0.03em;
}

.hero-sub {
  font-size: clamp(16px, 2vw, 21px);
  font-weight: 300;
  color: var(--gray-400);
  max-width: 560px;
  line-height: 1.7;
  margin-bottom: 48px;
  opacity: 0;
  animation: fadeUp 0.8s ease 0.4s forwards;
}

.hero-actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  justify-content: center;
  opacity: 0;
  animation: fadeUp 0.8s ease 0.55s forwards;
}

.btn-primary {
  font-family: 'Noto Sans JP', sans-serif;
  font-size: 15px;
  background: var(--black);
  color: var(--white);
  padding: 14px 32px;
  border-radius: 980px;
  text-decoration: none;
  letter-spacing: 0.02em;
  transition: transform 0.2s, background 0.2s;
  display: inline-block;
}
.btn-primary:hover { background: var(--gray-600); transform: scale(1.02); }

.btn-ghost {
  font-family: 'Noto Sans JP', sans-serif;
  font-size: 15px;
  background: transparent;
  color: var(--black);
  padding: 14px 32px;
  border-radius: 980px;
  border: 1px solid rgba(0,0,0,0.2);
  text-decoration: none;
  letter-spacing: 0.02em;
  transition: border-color 0.2s, transform 0.2s;
  display: inline-block;
}
.btn-ghost:hover { border-color: var(--black); transform: scale(1.02); }

.app-window {
    display: flex;
    justify-content: center;
    align-items: center;
}


/* FEATURES */
section { overflow: hidden; }

.section-intro {
  text-align: center;
  padding: 100px 24px 60px;
  background: var(--white);
}

.section-eyebrow {
  font-size: 13px;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--gray-400);
  margin-bottom: 16px;
}

.section-title {
  font-family: 'Noto Serif JP', serif;
  font-weight: 300;
  font-size: clamp(32px, 5vw, 56px);
  line-height: 1.15;
  letter-spacing: -0.01em;
  color: var(--black);
  max-width: 700px;
  margin: 0 auto 20px;
}

.section-body {
  font-size: 17px;
  font-weight: 300;
  color: var(--gray-400);
  max-width: 480px;
  margin: 0 auto;
  line-height: 1.7;
}

/* BENTO GRID */
.bento {
  padding: 0 24px 80px;
  max-width: 1100px;
  margin: 0 auto;
}

.bento-grid {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  grid-template-rows: auto;
  gap: 16px;
}

.bento-cell {
  background: var(--gray-100);
  border-radius: 20px;
  padding: 40px;
  overflow: hidden;
  position: relative;
  transition: transform 0.3s ease;
}
.bento-cell:hover { transform: scale(1.01); }

.bento-cell.wide { grid-column: span 8; }
.bento-cell.half { grid-column: span 6; }
.bento-cell.third { grid-column: span 4; }
.bento-cell.narrow { grid-column: span 4; }

.bento-cell-tag {
  font-size: 11px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--gray-400);
  margin-bottom: 12px;
}

.bento-cell-title {
  font-family: 'Noto Serif JP', serif;
  font-size: clamp(22px, 3vw, 34px);
  font-weight: 300;
  line-height: 1.25;
  color: var(--black);
  margin-bottom: 12px;
  letter-spacing: -0.01em;
}

.bento-cell-body {
  font-size: 14px;
  font-weight: 300;
  color: var(--gray-400);
  line-height: 1.65;
  max-width: 320px;
}

/* visual elements in bento */
.bento-visual {
  margin-top: 32px;
}

.kernel-diagram {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}

.kernel-layer {
  background: var(--black);
  color: var(--white);
  border-radius: 8px;
  padding: 8px 16px;
  font-size: 12px;
  letter-spacing: 0.05em;
  font-family: 'Noto Sans JP', sans-serif;
}

.kernel-arrow {
  color: var(--gray-400);
  font-size: 18px;
}

.kernel-layer.outlined {
  background: transparent;
  color: var(--black);
  border: 1px solid rgba(0,0,0,0.2);
}

.metric-row {
  display: flex;
  gap: 24px;
  margin-top: 28px;
}

.metric-item { flex: 1; }

.metric-num {
  font-family: 'Noto Serif JP', serif;
  font-size: 42px;
  font-weight: 300;
  line-height: 1;
  color: var(--black);
  letter-spacing: -0.02em;
}

.metric-unit { font-size: 18px; color: var(--gray-400); }

.metric-label {
  font-size: 12px;
  color: var(--gray-400);
  margin-top: 4px;
  letter-spacing: 0.03em;
}

.lang-badges {
  display: flex;
  gap: 8px;
  margin-top: 28px;
  flex-wrap: wrap;
}

.lang-badge {
  background: var(--white);
  border: 1px solid rgba(0,0,0,0.12);
  border-radius: 980px;
  padding: 6px 14px;
  font-size: 12px;
  font-family: 'Noto Sans JP', sans-serif;
  font-weight: 500;
  letter-spacing: 0.03em;
  color: var(--gray-600);
}

.lang-badge.active {
  background: var(--black);
  color: var(--white);
  border-color: var(--black);
}

.code-block {
  background: #0d0d0d;
  border-radius: 12px;
  padding: 20px;
  margin-top: 28px;
  font-family: 'SF Mono', 'Fira Code', monospace;
  font-size: 12px;
  line-height: 1.7;
  color: #aaa;
  overflow: hidden;
}

.code-block .kw { color: #ddd; font-weight: 500; }
.code-block .cm { color: #555; font-style: italic; }
.code-block .fn { color: #ccc; }
.code-block .lit { color: #999; }

/* DARK STRIP */
.dark-strip {
  background: var(--black);
  color: var(--white);
  padding: 100px 24px;
  text-align: center;
}

.dark-strip .section-title { color: var(--white); }
.dark-strip .section-body { color: rgba(255,255,255,0.45); }
.dark-strip .section-eyebrow { color: rgba(255,255,255,0.3); }

.spec-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1px;
  background: rgba(255,255,255,0.08);
  border: 1px solid rgba(255,255,255,0.08);
  border-radius: 16px;
  overflow: hidden;
  max-width: 900px;
  margin: 60px auto 0;
}

.spec-item {
  background: var(--black);
  padding: 36px 28px;
  text-align: left;
}

.spec-label {
  font-size: 11px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: rgba(255,255,255,0.3);
  margin-bottom: 8px;
}

.spec-value {
  font-family: 'Noto Serif JP', serif;
  font-size: 20px;
  font-weight: 300;
  color: var(--white);
  line-height: 1.3;
}

/* PHILOSOPHY */
.philosophy {
  padding: 100px 24px;
  max-width: 800px;
  margin: 0 auto;
  text-align: center;
}

.philosophy blockquote {
  font-family: 'Noto Serif JP', serif;
  font-size: clamp(24px, 3.5vw, 40px);
  font-weight: 300;
  line-height: 1.55;
  color: var(--black);
  letter-spacing: -0.01em;
  position: relative;
}

.philosophy blockquote::before {
  content: '';
  display: block;
  width: 40px;
  height: 1px;
  background: var(--black);
  margin: 0 auto 40px;
}

.philosophy figcaption {
  font-size: 13px;
  color: var(--gray-400);
  margin-top: 32px;
  letter-spacing: 0.05em;
}

/* CTA SECTION */
.cta-section {
  background: var(--gray-100);
  padding: 100px 24px;
  text-align: center;
}

.cta-title {
  font-family: 'Noto Serif JP', serif;
  font-size: clamp(32px, 5vw, 60px);
  font-weight: 300;
  color: var(--black);
  margin-bottom: 20px;
  letter-spacing: -0.01em;
}

.cta-sub {
  font-size: 17px;
  font-weight: 300;
  color: var(--gray-400);
  margin-bottom: 40px;
  line-height: 1.6;
}

.cta-buttons {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
}

/* FOOTER */
footer {
  background: var(--gray-100);
  border-top: 1px solid var(--gray-200);
  padding: 48px 24px 32px;
}

.footer-inner {
  max-width: 1100px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 2fr repeat(3, 1fr);
  gap: 40px;
}

.footer-brand {
  font-family: 'Noto Serif JP', serif;
  font-size: 22px;
  font-weight: 400;
  letter-spacing: 0.04em;
  color: var(--black);
  margin-bottom: 10px;
}

.footer-tagline {
  font-size: 13px;
  color: var(--gray-400);
  line-height: 1.6;
  max-width: 220px;
}

.footer-col-title {
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--black);
  margin-bottom: 16px;
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-links a {
  font-size: 13px;
  color: var(--gray-400);
  text-decoration: none;
  transition: color 0.2s;
}
.footer-links a:hover { color: var(--black); }

.footer-bottom {
  max-width: 1100px;
  margin: 40px auto 0;
  padding-top: 24px;
  border-top: 1px solid var(--gray-200);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}

.footer-copy {
  font-size: 12px;
  color: var(--gray-400);
  letter-spacing: 0.02em;
}

.footer-legal {
  display: flex;
  gap: 24px;
  list-style: none;
}

.footer-legal a {
  font-size: 12px;
  color: var(--gray-400);
  text-decoration: none;
  transition: color 0.2s;
}
.footer-legal a:hover { color: var(--black); }

/* ANIMATIONS */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(24px); }
  to   { opacity: 1; transform: translateY(0); }
}

.reveal {
  opacity: 0;
  transform: translateY(32px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}
.reveal.visible { opacity: 1; transform: translateY(0); }

/* RESPONSIVE */
@media (max-width: 768px) {
  .nav-links { display: none; }
  .bento-cell.wide,
  .bento-cell.half,
  .bento-cell.third,
  .bento-cell.narrow { grid-column: span 12; }
  .footer-inner { grid-template-columns: 1fr 1fr; }
  .screen-content { grid-template-columns: 1fr; }
  .screen-sidebar { display: none; }
  .screen-cards { grid-template-columns: repeat(2, 1fr); }
}