* {
  box-sizing: border-box;
}

html {
  color-scheme: dark;
}

body {
  margin: 0;
  background: var(--bg-base);
  color: var(--text-primary);
  font-family: var(--font-sans);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

img {
  max-width: 100%;
  display: block;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--accent-deep);
  color: var(--bg-base);
  padding: var(--space-2) var(--space-4);
  z-index: 100;
}
.skip-link:focus {
  left: var(--space-4);
  top: var(--space-4);
}

/* Contract band: always visible, top of page */
.ca-band {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  flex-wrap: wrap;
  padding: var(--space-3) var(--space-5);
  background: var(--bg-raised);
  border-bottom: 1px solid var(--border-subtle);
  font-size: 0.9rem;
}
.ca-band__label {
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  font-size: 0.7rem;
}
.ca-band__value {
  font-family: ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-primary);
  word-break: break-all;
}
.ca-band[data-ca-state="stated"] .ca-band__value {
  color: var(--accent-bright);
}
.ca-band__copy {
  min-height: var(--tap-min);
  min-width: var(--tap-min);
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-subtle);
  background: transparent;
  color: var(--text-primary);
  font-size: 0.85rem;
  cursor: pointer;
  transition: background-color var(--duration-fast) var(--ease-standard);
}
.ca-band__copy:not(:disabled):hover {
  background: var(--bg-panel);
}
.ca-band__copy:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}
.ca-band__copy[data-copied="true"] {
  border-color: var(--accent-deep);
  color: var(--accent-bright);
}
.ca-band__status {
  color: var(--text-muted);
  font-size: 0.8rem;
}

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  padding: var(--space-4) var(--space-5);
  flex-wrap: wrap;
}

.brand {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  text-decoration: none;
  color: var(--text-primary);
}
.brand__word {
  font-weight: 700;
  font-size: 1.1rem;
  letter-spacing: -0.01em;
}

.primary-nav {
  display: flex;
  gap: var(--space-5);
}
.primary-nav a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.95rem;
  min-height: var(--tap-min);
  display: inline-flex;
  align-items: center;
}
.primary-nav a:hover {
  color: var(--text-primary);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: var(--space-4);
}

.btn {
  min-height: var(--tap-min);
  padding: 0 var(--space-4);
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 600;
  border: 1px solid var(--border-subtle);
  cursor: pointer;
  transition: background-color var(--duration-fast) var(--ease-standard);
}
.btn--ghost {
  background: transparent;
  color: var(--text-primary);
}
.btn--ghost:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}

.social-row {
  display: flex;
  gap: var(--space-2);
}
.social-icon {
  width: var(--tap-min);
  height: var(--tap-min);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  text-decoration: none;
  transition: background-color var(--duration-fast) var(--ease-standard), color var(--duration-fast) var(--ease-standard);
}
.social-icon[aria-disabled="true"] {
  color: var(--text-muted);
  cursor: not-allowed;
  pointer-events: none;
  opacity: 0.5;
}
.social-icon[data-social-state="active"]:hover {
  color: var(--accent-bright);
  background: var(--bg-panel);
}

main {
  padding: 0 var(--space-5);
}

.hero {
  max-width: 46rem;
  margin: var(--space-8) auto var(--space-7);
  text-align: center;
}
.hero h1 {
  font-size: clamp(1.9rem, 4vw + 1rem, 3.2rem);
  line-height: 1.1;
  margin: 0 0 var(--space-4);
  letter-spacing: -0.02em;
}
.hero__sub {
  color: var(--text-secondary);
  font-size: 1.1rem;
  margin: 0 auto var(--space-5);
  max-width: 38rem;
}
.hero__cta-note {
  color: var(--text-muted);
  font-size: 0.85rem;
}

.chain-panel,
.how-it-works {
  max-width: 60rem;
  margin: 0 auto var(--space-8);
}
.chain-panel h2,
.how-it-works h2 {
  font-size: 1.5rem;
  margin-bottom: var(--space-4);
}

.chain-card {
  background: var(--bg-panel);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
  display: grid;
  gap: var(--space-3);
}
.chain-card__row {
  display: flex;
  justify-content: space-between;
  gap: var(--space-4);
  flex-wrap: wrap;
  border-bottom: 1px solid var(--border-subtle);
  padding-bottom: var(--space-3);
}
.chain-card__row:last-child {
  border-bottom: none;
  padding-bottom: 0;
}
.chain-card__label {
  color: var(--text-secondary);
  font-size: 0.85rem;
}
.chain-card__value {
  font-weight: 600;
  text-align: right;
}
.chain-card__value--mono {
  font-family: ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
  font-size: 0.85rem;
  word-break: break-all;
}
.chain-card__value--muted {
  color: var(--text-muted);
  font-weight: 400;
  font-size: 0.85rem;
}

.steps {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-5);
}
.step {
  background: var(--bg-panel);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: var(--space-5);
}
.step__index {
  color: var(--accent-deep);
  font-weight: 700;
  font-size: 0.85rem;
  letter-spacing: 0.08em;
}
.step h3 {
  margin: var(--space-2) 0 var(--space-2);
  font-size: 1.05rem;
}
.step p {
  color: var(--text-secondary);
  margin: 0;
  font-size: 0.92rem;
}

.how-it-works__note {
  margin-top: var(--space-5);
  color: var(--text-muted);
  font-size: 0.85rem;
  max-width: 42rem;
}

.site-footer {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-6) var(--space-5) var(--space-8);
  border-top: 1px solid var(--border-subtle);
  text-align: center;
}
.site-footer__brand {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-weight: 700;
}
.site-footer__tagline {
  color: var(--text-secondary);
  margin: 0;
  font-size: 0.95rem;
}
.site-footer__legal {
  color: var(--text-muted);
  font-size: 0.8rem;
  margin: 0;
}

@media (max-width: 640px) {
  .steps {
    grid-template-columns: 1fr;
  }
  .site-header {
    justify-content: center;
    text-align: center;
  }
  .header-actions {
    justify-content: center;
    width: 100%;
  }
  .chain-card__row {
    flex-direction: column;
    gap: var(--space-1);
  }
  .chain-card__value {
    text-align: left;
  }
}