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

:root {
  --black: #0a0a0a;
  --white: #fafafa;
  --g50:  #f7f7f7;
  --g100: #f2f2f2;
  --g200: #e4e4e4;
  --g300: #c8c8c8;
  --g400: #a0a0a0;
  --g600: #606060;
  --g800: #303030;
  --border: rgba(0,0,0,0.07);
  --border-s: rgba(0,0,0,0.13);
  --r: 18px;
  --rs: 10px;
  --nav: 54px;
  --font: 'DM Sans', 'Noto Sans JP', system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
  --mono: 'DM Mono', 'SF Mono', 'Cascadia Code', Consolas, monospace;
  --accent: #0a84ff;
  --accent-soft: rgba(10,132,255,0.10);
  --shadow-card: 0 1px 3px rgba(0,0,0,0.06), 0 6px 18px rgba(0,0,0,0.05);
  --shadow-hero: 0 18px 56px rgba(0,0,0,0.13);
}

html {
  scroll-behavior: smooth;
  background: var(--g50);
  color: var(--black);
  font-family: var(--font);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

body {
  overflow-x: hidden;
  background:
    radial-gradient(circle at 50% 0%, rgba(10,132,255,0.08), transparent 34rem),
    var(--g50);
}

img, svg {
  display: block;
}

a {
  color: inherit;
}

/* NAV */
nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  height: var(--nav);
  padding: 0 28px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--border);
  background: rgba(250,250,250,0.88);
  backdrop-filter: blur(24px);
  -webkit-backdrop-filter: blur(24px);
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--black);
  text-decoration: none;
  font-size: 15px;
  font-weight: 650;
  letter-spacing: -0.02em;
}

.nav-logo {
  width: 28px;
  height: 28px;
  border-radius: 8px;
  background: var(--black);
  display: grid;
  place-items: center;
  color: white;
  font-size: 14px;
  line-height: 1;
  font-weight: 700;
  letter-spacing: -0.06em;
}

.nav-tabs {
  display: flex;
  align-items: center;
  gap: 2px;
  list-style: none;
}

.nav-tab {
  display: inline-flex;
  align-items: center;
  height: 32px;
  padding: 0 14px;
  border-radius: 20px;
  color: var(--g600);
  text-decoration: none;
  font-size: 13px;
  font-weight: 520;
  transition: background 0.14s ease, color 0.14s ease;
}

.nav-tab:hover {
  background: var(--g100);
  color: var(--black);
}

.nav-cta {
  display: inline-flex;
  align-items: center;
  height: 32px;
  padding: 0 16px;
  border-radius: 20px;
  background: var(--black);
  color: white;
  text-decoration: none;
  font-size: 13px;
  font-weight: 650;
  transition: transform 0.14s ease, background 0.14s ease;
}

.nav-cta:hover {
  background: var(--g800);
  transform: translateY(-1px);
}

/* COMMON */
main {
  padding-top: var(--nav);
}

.section {
  max-width: 1120px;
  margin: 0 auto;
  padding: 92px 28px;
}

.section.compact {
  padding-top: 56px;
}

.section-intro {
  max-width: 760px;
  margin: 0 auto 38px;
  text-align: center;
}

.eyebrow,
.section-eyebrow,
.card-tag,
.spec-label,
.footer-col-title {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.10em;
  text-transform: uppercase;
  color: var(--g400);
}

.section-title {
  margin-top: 12px;
  font-size: clamp(34px, 5vw, 62px);
  line-height: 1.04;
  letter-spacing: -0.055em;
  font-weight: 750;
}

.section-body {
  max-width: 640px;
  margin: 18px auto 0;
  color: var(--g600);
  font-size: 16px;
  line-height: 1.85;
  font-weight: 400;
}

.btn-primary,
.btn-ghost {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 24px;
  border-radius: 999px;
  text-decoration: none;
  font-size: 14px;
  font-weight: 700;
  transition: transform 0.14s ease, background 0.14s ease, border-color 0.14s ease, color 0.14s ease;
}

.btn-primary {
  background: var(--black);
  color: white;
}

.btn-primary:hover {
  background: var(--g800);
  transform: translateY(-1px);
}

.btn-ghost {
  background: rgba(255,255,255,0.62);
  border: 1px solid var(--border-s);
  color: var(--black);
}

.btn-ghost:hover {
  background: white;
  border-color: rgba(0,0,0,0.22);
  transform: translateY(-1px);
}

/* HERO */
.hero {
  min-height: calc(100vh - var(--nav));
  max-width: 1180px;
  margin: 0 auto;
  padding: 86px 28px 64px;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  align-items: center;
  text-align: center;
}

.hero-inner {
  max-width: 980px;
  margin: 0 auto;
}

.hero-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 13px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: rgba(255,255,255,0.70);
  color: var(--g600);
  font-size: 12px;
  font-weight: 650;
  letter-spacing: -0.01em;
  box-shadow: var(--shadow-card);
  animation: fadeUp 0.7s ease 0.05s both;
}

.hero-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 0 4px var(--accent-soft);
}

.hero-title {
  margin-top: 26px;
  font-size: clamp(58px, 11vw, 138px);
  line-height: 0.92;
  letter-spacing: -0.085em;
  font-weight: 800;
  animation: fadeUp 0.7s ease 0.18s both;
}

.hero-sub {
  max-width: 690px;
  margin: 28px auto 0;
  color: var(--g600);
  font-size: clamp(17px, 2.1vw, 23px);
  line-height: 1.7;
  letter-spacing: -0.025em;
  animation: fadeUp 0.7s ease 0.30s both;
}

.hero-actions {
  margin-top: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
  animation: fadeUp 0.7s ease 0.42s both;
}

.hero-preview {
  max-width: 860px;
  margin: 58px auto 0;
  border: 1px solid var(--border-s);
  border-radius: 28px;
  background: rgba(255,255,255,0.78);
  box-shadow: var(--shadow-hero);
  overflow: hidden;
  text-align: left;
  animation: fadeUp 0.7s ease 0.54s both;
}

.preview-bar {
  height: 44px;
  padding: 0 16px;
  display: flex;
  align-items: center;
  gap: 8px;
  border-bottom: 1px solid var(--border);
  background: rgba(250,250,250,0.86);
}

.window-dot {
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--g300);
}

.preview-titlebar {
  margin-left: 8px;
  color: var(--g400);
  font-size: 12px;
  font-family: var(--mono);
}

.preview-body {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  min-height: 300px;
}

.preview-left {
  padding: 34px;
  background: var(--black);
  color: white;
}

.preview-label {
  color: rgba(255,255,255,0.45);
  font-size: 11px;
  font-family: var(--mono);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.preview-command {
  margin-top: 18px;
  font-family: var(--mono);
  font-size: clamp(22px, 3vw, 36px);
  line-height: 1.35;
  letter-spacing: -0.045em;
}

.preview-command span {
  color: var(--accent);
}

.preview-log {
  margin-top: 30px;
  display: grid;
  gap: 10px;
}

.log-line {
  display: flex;
  align-items: center;
  gap: 10px;
  color: rgba(255,255,255,0.56);
  font-size: 12px;
  font-family: var(--mono);
}

.log-pill {
  display: inline-flex;
  min-width: 54px;
  justify-content: center;
  border: 1px solid rgba(255,255,255,0.14);
  border-radius: 999px;
  padding: 3px 8px;
  color: rgba(255,255,255,0.82);
}

.preview-right {
  padding: 26px;
  background: linear-gradient(180deg, var(--white), var(--g100));
}

.preview-card {
  height: 100%;
  border: 1px solid var(--border);
  border-radius: 20px;
  background: rgba(255,255,255,0.82);
  padding: 22px;
  box-shadow: var(--shadow-card);
}

.preview-card-title {
  font-size: 15px;
  font-weight: 720;
  letter-spacing: -0.025em;
}

.preview-stack {
  margin-top: 18px;
  display: grid;
  gap: 10px;
}

.preview-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  padding: 12px;
  border-radius: 14px;
  background: var(--g50);
  border: 1px solid var(--border);
}

.preview-row strong {
  font-size: 13px;
  font-weight: 700;
}

.preview-row small {
  color: var(--g400);
  font-size: 11px;
  font-family: var(--mono);
}

.preview-status {
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 0 4px var(--accent-soft);
  flex-shrink: 0;
}

/* QUICK STATS */
.quick-stats {
  max-width: 1120px;
  margin: -16px auto 0;
  padding: 0 28px 44px;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
}

.stat-card {
  border: 1px solid var(--border);
  border-radius: var(--r);
  background: rgba(255,255,255,0.74);
  box-shadow: var(--shadow-card);
  padding: 18px;
}

.stat-value {
  font-size: 24px;
  font-weight: 760;
  letter-spacing: -0.045em;
}

.stat-label {
  margin-top: 5px;
  color: var(--g400);
  font-size: 12px;
}

/* BENTO */
.bento-grid {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: 14px;
}

.bento-cell {
  min-height: 250px;
  padding: 28px;
  border: 1px solid var(--border);
  border-radius: 24px;
  background: rgba(255,255,255,0.76);
  box-shadow: var(--shadow-card);
  overflow: hidden;
  position: relative;
  transition: transform 0.18s ease, box-shadow 0.18s ease;
}

.bento-cell:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 28px rgba(0,0,0,0.09);
}

.bento-cell.wide { grid-column: span 8; }
.bento-cell.narrow { grid-column: span 4; }
.bento-cell.half { grid-column: span 6; }
.bento-cell.third { grid-column: span 4; }
.bento-cell.full { grid-column: span 12; }

.bento-cell.dark {
  background: var(--black);
  color: white;
}

.bento-cell.dark .card-tag,
.bento-cell.dark .bento-cell-body {
  color: rgba(255,255,255,0.48);
}

.bento-cell-title {
  margin-top: 12px;
  font-size: clamp(24px, 3vw, 38px);
  line-height: 1.12;
  letter-spacing: -0.055em;
  font-weight: 760;
}

.bento-cell-body {
  max-width: 420px;
  margin-top: 14px;
  color: var(--g600);
  font-size: 14px;
  line-height: 1.75;
}

.kernel-diagram {
  margin-top: 32px;
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.kernel-layer {
  padding: 8px 13px;
  border-radius: 999px;
  background: white;
  color: var(--black);
  font-size: 12px;
  font-weight: 700;
}

.kernel-arrow {
  color: rgba(255,255,255,0.35);
}

.metric-row {
  margin-top: 28px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

.metric-item {
  border-radius: 18px;
  background: var(--g50);
  border: 1px solid var(--border);
  padding: 16px;
}

.metric-num {
  font-size: 36px;
  font-weight: 780;
  line-height: 1;
  letter-spacing: -0.06em;
}

.metric-unit {
  margin-left: 2px;
  color: var(--g400);
  font-size: 14px;
  font-weight: 650;
  letter-spacing: -0.02em;
}

.metric-label {
  margin-top: 7px;
  color: var(--g400);
  font-size: 11px;
}

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

.lang-badge {
  display: inline-flex;
  align-items: center;
  height: 30px;
  padding: 0 13px;
  border-radius: 999px;
  border: 1px solid var(--border-s);
  background: white;
  color: var(--g600);
  font-size: 12px;
  font-weight: 700;
}

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

.code-block {
  margin-top: 24px;
  padding: 18px;
  border-radius: 16px;
  background: #111;
  color: #a9a9a9;
  font-family: var(--mono);
  font-size: 12px;
  line-height: 1.75;
  overflow-x: auto;
}

.code-block .cm { color: #666; font-style: italic; }
.code-block .kw { color: #f0f0f0; }
.code-block .fn { color: #d0d0d0; }
.code-block .lit { color: #8fc7ff; }

.inline-link {
  display: inline-flex;
  margin-top: 18px;
  color: var(--accent);
  font-size: 13px;
  font-weight: 700;
  text-decoration: none;
}

.inline-link:hover {
  opacity: 0.75;
}

/* SPECS */
.dark-strip {
  background: var(--black);
  color: white;
  padding: 100px 28px;
}

.dark-strip-inner {
  max-width: 1120px;
  margin: 0 auto;
  text-align: center;
}

.dark-strip .section-title {
  color: white;
}

.dark-strip .section-body,
.dark-strip .section-eyebrow {
  color: rgba(255,255,255,0.46);
}

.spec-grid {
  max-width: 920px;
  margin: 46px auto 0;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  overflow: hidden;
  border: 1px solid rgba(255,255,255,0.10);
  border-radius: 22px;
  background: rgba(255,255,255,0.10);
}

.spec-item {
  padding: 28px;
  text-align: left;
  background: #0f0f0f;
}

.spec-label {
  color: rgba(255,255,255,0.34);
}

.spec-value {
  margin-top: 8px;
  color: white;
  font-size: 21px;
  line-height: 1.25;
  letter-spacing: -0.035em;
  font-weight: 720;
}

/* PHILOSOPHY */
.philosophy {
  max-width: 900px;
  margin: 0 auto;
  padding: 110px 28px;
  text-align: center;
}

.philosophy blockquote {
  font-size: clamp(28px, 4.3vw, 52px);
  line-height: 1.28;
  letter-spacing: -0.065em;
  font-weight: 780;
}

.philosophy blockquote::before {
  content: '';
  display: block;
  width: 40px;
  height: 3px;
  margin: 0 auto 34px;
  border-radius: 999px;
  background: var(--black);
}

.philosophy figcaption {
  margin-top: 28px;
  color: var(--g400);
  font-size: 13px;
}

/* CTA */
.cta-section {
  max-width: 1120px;
  margin: 0 auto 34px;
  padding: 0 28px;
}

.cta-card {
  padding: 64px 32px;
  border: 1px solid var(--border);
  border-radius: 28px;
  background: rgba(255,255,255,0.80);
  box-shadow: var(--shadow-card);
  text-align: center;
}

.cta-title {
  font-size: clamp(34px, 5vw, 60px);
  line-height: 1.05;
  letter-spacing: -0.06em;
  font-weight: 780;
}

.cta-sub {
  margin-top: 18px;
  color: var(--g600);
  font-size: 16px;
  line-height: 1.75;
}

.cta-buttons {
  margin-top: 30px;
  display: flex;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
}

/* CONTRIBUTE */
.page-hero {
  max-width: 980px;
  margin: 0 auto;
  padding: 132px 28px 64px;
  text-align: center;
}

.page-title {
  margin-top: 16px;
  font-size: clamp(44px, 7vw, 86px);
  line-height: 0.98;
  letter-spacing: -0.075em;
  font-weight: 800;
}

.page-sub {
  max-width: 720px;
  margin: 24px auto 0;
  color: var(--g600);
  font-size: 16px;
  line-height: 1.9;
}

.guide-section {
  max-width: 980px;
  margin: 0 auto;
  padding: 0 28px 86px;
}

.guide-list {
  display: grid;
  gap: 14px;
}

.guide-card {
  border: 1px solid var(--border);
  border-radius: 24px;
  background: rgba(255,255,255,0.78);
  box-shadow: var(--shadow-card);
  padding: 28px;
}

.guide-card-head {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 16px;
  align-items: start;
}

.guide-num {
  width: 42px;
  height: 42px;
  border-radius: 12px;
  background: var(--black);
  color: white;
  display: grid;
  place-items: center;
  font-family: var(--mono);
  font-size: 13px;
}

.guide-title {
  font-size: clamp(24px, 3vw, 36px);
  line-height: 1.15;
  letter-spacing: -0.055em;
  font-weight: 760;
}

.guide-body {
  margin-top: 18px;
  padding-left: 58px;
  color: var(--g600);
  font-size: 14px;
  line-height: 1.85;
}

.guide-body p + p,
.guide-body ol + p,
.guide-body p + ol {
  margin-top: 14px;
}

.guide-body ol {
  padding-left: 20px;
}

.guide-body li + li {
  margin-top: 7px;
}

.guide-body a {
  color: var(--accent);
  font-weight: 700;
  text-decoration: none;
}

.guide-body a:hover {
  opacity: 0.75;
}

code {
  border: 1px solid var(--border);
  border-radius: 7px;
  background: var(--g100);
  padding: 2px 6px;
  color: var(--g800);
  font-family: var(--mono);
  font-size: 0.92em;
}

/* FOOTER */
footer {
  border-top: 1px solid var(--border);
  background: rgba(250,250,250,0.86);
  padding: 46px 28px 32px;
}

.footer-inner {
  max-width: 1120px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 40px;
}

.footer-brand {
  font-size: 18px;
  font-weight: 760;
  letter-spacing: -0.035em;
}

.footer-tagline {
  max-width: 300px;
  margin-top: 10px;
  color: var(--g400);
  font-size: 13px;
  line-height: 1.7;
}

.footer-col-title {
  color: var(--black);
  margin-bottom: 13px;
}

.footer-links {
  list-style: none;
  display: grid;
  gap: 9px;
}

.footer-links a {
  color: var(--g600);
  text-decoration: none;
  font-size: 13px;
}

.footer-links a:hover {
  color: var(--black);
}

.footer-bottom {
  max-width: 1120px;
  margin: 34px auto 0;
  padding-top: 22px;
  border-top: 1px solid var(--border);
}

.footer-copy {
  color: var(--g400);
  font-size: 12px;
}

/* ANIMATION */
@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(18px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.reveal {
  opacity: 0;
  transform: translateY(22px);
  transition: opacity 0.65s ease, transform 0.65s ease;
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* RESPONSIVE */
@media (max-width: 860px) {
  nav {
    padding: 0 16px;
  }

  .nav-tabs {
    display: none;
  }

  .hero {
    padding: 72px 20px 52px;
  }

  .hero-title {
    letter-spacing: -0.07em;
  }

  .preview-body {
    grid-template-columns: 1fr;
  }

  .preview-right {
    display: none;
  }

  .quick-stats {
    grid-template-columns: repeat(2, 1fr);
    padding: 0 20px 34px;
  }

  .section,
  .philosophy,
  .dark-strip {
    padding-left: 20px;
    padding-right: 20px;
  }

  .bento-cell.wide,
  .bento-cell.narrow,
  .bento-cell.half,
  .bento-cell.third,
  .bento-cell.full {
    grid-column: span 12;
  }

  .spec-grid {
    grid-template-columns: 1fr 1fr;
  }

  .footer-inner {
    grid-template-columns: 1fr 1fr;
  }

  .guide-body {
    padding-left: 0;
  }
}

@media (max-width: 560px) {
  .nav-cta {
    display: none;
  }

  .hero-actions,
  .cta-buttons {
    flex-direction: column;
  }

  .btn-primary,
  .btn-ghost {
    width: 100%;
  }

  .quick-stats,
  .spec-grid,
  .metric-row,
  .footer-inner {
    grid-template-columns: 1fr;
  }

  .bento-cell,
  .guide-card {
    padding: 22px;
  }

  .guide-card-head {
    grid-template-columns: 1fr;
  }
}