:root {
  --paper: #f4f6f7;
  --ink: #1d242c;
  --steel: #5c6b7a;
  --brass: #9c7a2e;
  --brass-deep: #7d6124;
  --panel: #141a21;
  --panel-ink: #d7dee6;
  --line: #d3dae0;
  --mono: ui-monospace, "SF Mono", Menlo, Consolas, "Cascadia Code", monospace;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
}

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

html { -webkit-text-size-adjust: 100%; }

body {
  font-family: var(--sans);
  background: var(--paper);
  color: var(--ink);
  line-height: 1.6;
  font-size: 1.0625rem;
}

.page {
  max-width: 41rem;
  margin: 0 auto;
  padding: 4.5rem 1.5rem 3rem;
}

a { color: var(--brass-deep); text-underline-offset: 3px; }
a:hover { color: var(--ink); }
a:focus-visible, button:focus-visible, .cta:focus-visible {
  outline: 2px solid var(--brass);
  outline-offset: 3px;
}

/* wordmark + display type */
.wordmark {
  font-family: var(--mono);
  font-size: 0.9375rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  color: var(--steel);
  text-decoration: none;
}
.wordmark b { color: var(--ink); font-weight: 600; }

h1 {
  font-family: var(--mono);
  font-weight: 650;
  font-size: clamp(1.9rem, 5.5vw, 2.6rem);
  line-height: 1.15;
  letter-spacing: -0.03em;
  margin: 2.75rem 0 1rem;
}

.tagline {
  font-size: 1.1875rem;
  color: var(--steel);
  max-width: 34rem;
  margin-bottom: 2.5rem;
}

.eyebrow {
  font-family: var(--mono);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--brass-deep);
  margin: 3.25rem 0 1rem;
}

/* signature: server-sees / you-see panel */
.cipher {
  background: var(--panel);
  color: var(--panel-ink);
  border-radius: 10px;
  padding: 1.4rem 1.5rem;
  font-family: var(--mono);
  font-size: 0.8125rem;
  line-height: 1.5;
  margin-bottom: 2.5rem;
}
.cipher .row { display: block; }
.cipher .row + .row { margin-top: 1.1rem; }
.cipher .label {
  display: block;
  font-size: 0.6875rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: #8494a5;
  margin-bottom: 0.3rem;
}
.cipher .enc {
  color: #9fb0c2;
  word-break: break-all;
}
.cipher .enc .sep { color: #55647a; }
.cipher .plain { color: #e8c96a; font-size: 1rem; }

/* platforms */
.platforms {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin-bottom: 1rem;
}
.platform {
  border: 1px solid var(--line);
  border-radius: 10px;
  background: #fff;
  padding: 1.3rem 1.4rem;
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
  align-items: flex-start;
}
.platform h2 {
  font-family: var(--mono);
  font-size: 1.0625rem;
  font-weight: 650;
}
.platform p { color: var(--steel); font-size: 0.9375rem; flex: 1; }
@media (max-width: 34rem) {
  .platforms { grid-template-columns: 1fr; }
}

/* CTA */
.cta {
  display: inline-block;
  font-family: var(--mono);
  font-size: 0.9375rem;
  font-weight: 600;
  color: var(--paper);
  background: var(--ink);
  text-decoration: none;
  padding: 0.85rem 1.5rem;
  border-radius: 8px;
  border: 1px solid var(--ink);
}
.cta:hover { background: var(--brass-deep); border-color: var(--brass-deep); color: var(--paper); }
.cta-note {
  font-size: 0.875rem;
  color: var(--steel);
  margin-top: 0.75rem;
}

/* features as a definition grid */
.features {
  display: grid;
  grid-template-columns: max-content 1fr;
  gap: 0.65rem 1.5rem;
}
.features dt {
  font-family: var(--mono);
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--ink);
  padding-top: 0.15rem;
  white-space: nowrap;
}
.features dd { color: var(--steel); }

/* requirements checklist */
.requirements {
  border: 1px solid var(--line);
  border-left: 3px solid var(--brass);
  border-radius: 8px;
  padding: 1.3rem 1.5rem;
  background: #fff;
}
.requirements h2 {
  font-family: var(--mono);
  font-size: 0.9375rem;
  font-weight: 650;
  margin-bottom: 0.75rem;
}
.requirements ul { list-style: none; }
.requirements li {
  padding-left: 1.4rem;
  position: relative;
  margin-bottom: 0.5rem;
  color: var(--steel);
}
.requirements li::before {
  content: "▪";
  color: var(--brass);
  position: absolute;
  left: 0.2rem;
}
.requirements strong { color: var(--ink); font-weight: 600; }

/* prose pages (privacy, support) */
.prose h1 { margin-bottom: 0.5rem; }
.prose .dateline {
  font-family: var(--mono);
  font-size: 0.8125rem;
  color: var(--steel);
  margin-bottom: 2.25rem;
}
.prose h2 {
  font-family: var(--mono);
  font-size: 1.0625rem;
  font-weight: 650;
  letter-spacing: -0.01em;
  margin: 2.25rem 0 0.6rem;
}
.prose p { margin-bottom: 1rem; max-width: 38rem; }
.prose ul { margin: 0 0 1rem 1.25rem; }
.prose li { margin-bottom: 0.4rem; }

footer {
  margin-top: 4.5rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--line);
  display: flex;
  gap: 1.5rem;
  align-items: baseline;
  font-family: var(--mono);
  font-size: 0.8125rem;
  color: var(--steel);
}
footer .spacer { flex: 1; }
.trademark {
  margin-top: 1.25rem;
  max-width: 46rem;
  font-family: var(--mono);
  font-size: 0.75rem;
  line-height: 1.5;
  color: var(--steel);
}
footer a { color: var(--steel); }
footer a:hover { color: var(--ink); }

@media (max-width: 34rem) {
  .page { padding-top: 3rem; }
  .features { grid-template-columns: 1fr; gap: 0.1rem; }
  .features dt { padding-top: 0.6rem; }
  footer { flex-wrap: wrap; gap: 0.75rem 1.5rem; }
}

@media (prefers-reduced-motion: no-preference) {
  .cta { transition: background 140ms ease, border-color 140ms ease; }
}