/* The same monochrome constraint as the app (§3): black, white, one hue
   channel, one geometric sans. The landing page is the only surface where
   purchasing happens (§11.2), so it has to look like the product rather than
   like a marketing site bolted onto it. */

:root {
  --bg: #000000;
  --surface: #0A0A0A;
  --border: #1F1F1F;
  --border-strong: #333333;
  --muted: #6E6E6E;
  --secondary: #A3A3A3;
  --text: #FFFFFF;
  --measure: 62ch;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 400 16px/1.6 Inter, -apple-system, BlinkMacSystemFont, "Segoe UI",
        system-ui, sans-serif;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--text); text-decoration: none; }
a:hover { text-decoration: underline; }

.bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 24px;
  border-bottom: 1px solid var(--border);
}

/* The logo mark: an R with the 45° slash through it. The diagonal is the
   app's entire visual signature and the only non-rectilinear element. */
.mark {
  position: relative;
  font-weight: 600;
  font-size: 24px;
  letter-spacing: -0.02em;
  display: inline-block;
  width: 1.4em;
}
.mark .slash {
  position: absolute;
  left: 0.1em;
  top: -0.15em;
  width: 1px;
  height: 1.5em;
  background: var(--text);
  transform: rotate(45deg);
  transform-origin: center;
}

.bar nav a { margin-left: 20px; color: var(--secondary); font-size: 14px; }
.bar nav a:last-child { color: var(--text); }

main { max-width: 900px; margin: 0 auto; padding: 0 24px; }

section { padding: 64px 0; border-bottom: 1px solid var(--border); }
section:last-child { border-bottom: 0; }

h1 {
  font-size: clamp(28px, 5vw, 44px);
  font-weight: 600;
  letter-spacing: -0.02em;
  line-height: 1.15;
  margin: 0 0 20px;
}

h2 {
  font-size: 20px;
  font-weight: 600;
  margin: 0 0 12px;
}

p { max-width: var(--measure); color: var(--secondary); }
.lede { font-size: 18px; color: var(--secondary); }
.note { color: var(--muted); font-size: 14px; }
.fine { color: var(--muted); font-size: 13px; }

/* The one filled affordance on the page, mirroring the app's primary button:
   white fill, black text, no colour anywhere. */
.cta {
  display: inline-block;
  margin: 24px 0 10px;
  padding: 13px 26px;
  background: var(--text);
  color: var(--bg);
  border-radius: 8px;
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}
.cta:hover { text-decoration: none; opacity: 0.9; }

.pipe pre {
  overflow-x: auto;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 20px;
  font-size: 12px;
  line-height: 1.5;
  color: var(--secondary);
}

.cols { display: grid; gap: 40px; grid-template-columns: 1fr 1fr; }
@media (max-width: 720px) { .cols { grid-template-columns: 1fr; } }

.scope ul { padding-left: 20px; max-width: var(--measure); color: var(--secondary); }
.scope li { margin-bottom: 10px; }
.scope strong { color: var(--text); font-weight: 500; }

/* Pricing ---------------------------------------------------------------- */

.plans { display: grid; gap: 20px; grid-template-columns: repeat(3, 1fr); }
@media (max-width: 820px) { .plans { grid-template-columns: 1fr; } }

.plan {
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 24px;
  background: var(--surface);
  display: flex;
  flex-direction: column;
}
.plan.featured { border-color: var(--border-strong); }

.plan h3 {
  margin: 0 0 4px;
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}
.price { font-size: 32px; font-weight: 600; letter-spacing: -0.02em; margin: 8px 0 2px; }
.per { color: var(--muted); font-size: 13px; margin: 0 0 20px; }

.plan ul { list-style: none; padding: 0; margin: 0 0 24px; flex: 1; }
.plan li {
  color: var(--secondary);
  font-size: 14px;
  padding: 6px 0;
  border-bottom: 1px solid var(--border);
}
.plan li:last-child { border-bottom: 0; }
/* Withheld features are dimmed rather than removed — a gap in the list is
   less honest than showing what you are not getting. */
.plan li.off { color: var(--muted); }

.toggle { display: flex; gap: 8px; justify-content: center; margin-bottom: 32px; }
.toggle button {
  background: transparent;
  color: var(--secondary);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 8px 18px;
  font: inherit;
  font-size: 13px;
  cursor: pointer;
}
.toggle button[aria-pressed="true"] {
  background: var(--text);
  color: var(--bg);
  border-color: var(--text);
}

.buy {
  display: block;
  width: 100%;
  padding: 12px;
  background: var(--text);
  color: var(--bg);
  border: 0;
  border-radius: 8px;
  font: inherit;
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  cursor: pointer;
  text-align: center;
}
.buy.ghost { background: transparent; color: var(--text); border: 1px solid var(--border); }
.buy:disabled { background: var(--surface); color: var(--muted); cursor: default; }

/* Failure without a colour to spend: a 2px left rule and full-strength text,
   the same encoding the app uses (§3.3). */
.error {
  border-left: 2px solid var(--text);
  background: var(--surface);
  padding: 12px;
  margin-top: 16px;
  font-size: 14px;
  color: var(--text);
}
.error:empty { display: none; }

/* Legal ------------------------------------------------------------------ */

.legal { max-width: var(--measure); }
.legal h2 { margin-top: 32px; }
.legal p, .legal li { color: var(--secondary); }
.legal ul { padding-left: 20px; }

footer {
  border-top: 1px solid var(--border);
  padding: 32px 24px;
  text-align: center;
}
footer a { color: var(--secondary); font-size: 14px; }
footer p { margin: 6px auto; }