:root { --bg: #05070a; --fg: #e7ecf3; --muted: #9aa6b5; --line: #1d2633; --accent: #2dd4bf; --btn: #0f766e; --card: #0b1118; --pq: #a78bfa; }
@media (prefers-color-scheme: light) { :root { --bg: #f7f9fb; --fg: #0b1220; --muted: #4b5767; --line: #dde3ea; --accent: #0f766e; --btn: #0f766e; --card: #ffffff; --pq: #6d28d9; } }
* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--fg); font: 16px/1.65 system-ui, -apple-system, "Segoe UI", "Noto Sans", "Noto Sans Thai", sans-serif; }
header, main, footer { max-width: 820px; margin: 0 auto; padding: 0 16px; }
header { display: flex; flex-wrap: wrap; gap: 12px; align-items: center; justify-content: space-between; padding-top: 20px; padding-bottom: 12px; border-bottom: 1px solid var(--line); }
.brand { display: flex; gap: 10px; align-items: center; color: var(--fg); text-decoration: none; font-weight: 700; letter-spacing: .04em; }
nav { display: flex; flex-wrap: wrap; gap: 6px 12px; font-size: 14px; }
nav a { color: var(--muted); text-decoration: none; }
nav a:hover { color: var(--fg); }
h1 { font-size: clamp(28px, 6vw, 40px); line-height: 1.2; margin: 32px 0 12px; }
h2 { font-size: 22px; margin: 36px 0 8px; }
.lead { font-size: 18px; color: var(--fg); }
p, li { color: var(--fg); }
.note { color: var(--muted); font-size: 15px; }
a { color: var(--accent); }
.cta { display: flex; flex-wrap: wrap; gap: 10px; margin: 20px 0 8px; }
.btn { display: inline-block; padding: 10px 16px; border-radius: 10px; background: var(--btn); color: #fff; text-decoration: none; font-weight: 600; }
.btn.alt { background: transparent; color: var(--accent); border: 1px solid var(--accent); }
footer { margin-top: 40px; padding-top: 16px; padding-bottom: 32px; border-top: 1px solid var(--line); color: var(--muted); font-size: 14px; }

/* feature cards */
.cards { list-style: none; padding: 0; margin: 16px 0; display: grid; grid-template-columns: repeat(auto-fill, minmax(230px, 1fr)); gap: 12px; }
.cards li { display: flex; gap: 12px; align-items: flex-start; background: var(--card); border: 1px solid var(--line); border-radius: 12px; padding: 14px; }
.cards b { display: block; margin-bottom: 2px; }
.cards span { color: var(--muted); font-size: 15px; line-height: 1.5; }
.ic { flex: none; width: 26px; height: 26px; color: var(--accent); margin-top: 2px; }
.ic.big { width: 34px; height: 34px; }

/* the chain: three blocks, each with transactions and a post-quantum certificate */
.chainfig, .flowfig { margin: 18px 0; }
.blocks { display: flex; align-items: center; gap: 0; }
.blk { flex: 1; min-width: 0; border: 1px solid var(--line); border-radius: 12px; background: var(--card); padding: 10px; }
.blk-h { font: 600 13px/1.4 ui-monospace, SFMono-Regular, Menlo, monospace; color: var(--muted); margin-bottom: 8px; }
.blk-r { display: flex; gap: 8px; align-items: center; font-size: 13px; line-height: 1.35; padding: 8px; border-radius: 8px; border: 1px dashed var(--line); }
.blk-r + .blk-r { margin-top: 6px; }
.blk-r .ic { width: 20px; height: 20px; margin: 0; }
.blk-r.pq { border: 1px solid var(--pq); color: var(--fg); }
.blk-r.pq .ic { color: var(--pq); }
.link { flex: none; width: 22px; height: 2px; background: var(--line); position: relative; }
.link::after { content: ""; position: absolute; right: -1px; top: -4px; border: 5px solid transparent; border-left-color: var(--line); border-right: 0; }
figcaption { color: var(--muted); font-size: 14px; margin-top: 8px; }
.flowfig figcaption { color: var(--fg); font-weight: 600; font-size: 16px; margin: 0 0 10px; }

/* Neuro's four steps */
.flow { list-style: none; padding: 0; margin: 0; display: grid; grid-template-columns: repeat(4, 1fr); gap: 12px; counter-reset: none; }
.flow li { position: relative; display: flex; flex-direction: column; gap: 8px; background: var(--card); border: 1px solid var(--line); border-radius: 12px; padding: 14px; font-size: 15px; line-height: 1.45; }
.flow li:not(:last-child)::after { content: ""; position: absolute; right: -10px; top: 50%; border: 6px solid transparent; border-left-color: var(--accent); border-right: 0; transform: translateY(-50%); }
.flow .n { font: 700 12px/1 ui-monospace, monospace; color: var(--bg); background: var(--accent); width: 22px; height: 22px; border-radius: 11px; display: grid; place-items: center; }
@media (max-width: 640px) {
  .blocks { flex-direction: column; align-items: stretch; }
  .blk:nth-child(n+4) { display: none; }
  .link { width: 2px; height: 16px; margin: 0 auto; }
  .link::after { right: -4px; top: auto; bottom: -1px; border: 5px solid transparent; border-top-color: var(--line); border-bottom: 0; }
  .blocks > .link:nth-of-type(n+2) { display: none; }
  .flow { grid-template-columns: 1fr; }
  .flow li { flex-direction: row; align-items: center; }
  .flow li:not(:last-child)::after { right: auto; left: 50%; top: auto; bottom: -11px; border: 6px solid transparent; border-top-color: var(--accent); border-bottom: 0; transform: translateX(-50%); }
}