:root {
  color-scheme: light;
  --bg: #f4f6fb;
  --surface: #ffffff;
  --slate: #363e54;        /* the box in the logo */
  --slate-deep: #232a3b;
  --ink: #141c3f;          /* "Cipher" navy */
  --ink-soft: #5b6480;
  --line: #dde3ef;
  --accent: #2f6ef0;       /* "box" blue */
  --accent-dark: #1c4fcc;
  --accent-soft: #eaf0fe;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Helvetica, Arial, sans-serif;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--accent-dark); }

code, pre {
  font-family: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
}

/* Header */
header {
  border-bottom: 1px solid var(--line);
  background: rgba(244, 246, 251, .88);
  backdrop-filter: blur(8px);
  position: sticky;
  top: 0;
  z-index: 10;
}

.nav {
  max-width: 940px;
  margin: 0 auto;
  padding: 12px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.05rem;
  letter-spacing: -.01em;
  text-decoration: none;
  color: var(--ink);
}

/* crops the logo down to just the box, dropping the wordmark */
.brand-mark {
  position: relative;
  flex: none;
  width: 30px;
  height: 30px;
  border-radius: 8px;
  overflow: hidden;
  background: #fff;
}

.brand-mark img {
  position: absolute;
  width: 172%;
  left: -31%;
  top: -13%;
}

.brand-accent { color: var(--accent); }

.nav-links {
  display: flex;
  gap: 18px;
  font-size: .92rem;
}

.nav-links a {
  text-decoration: none;
  color: var(--ink-soft);
}

.nav-links a:hover { color: var(--accent); }

/* Layout */
main {
  max-width: 940px;
  margin: 0 auto;
  padding: 0 24px;
}

section { padding: 56px 0; }
section + section { border-top: 1px solid var(--line); }

h1 {
  font-size: clamp(2rem, 5vw, 2.9rem);
  line-height: 1.15;
  letter-spacing: -.025em;
  margin: 0 0 18px;
}

h2 {
  font-size: 1.5rem;
  letter-spacing: -.015em;
  margin: 0 0 14px;
}

h3 {
  font-size: 1.02rem;
  margin: 0 0 6px;
}

p { margin: 0 0 14px; }

.lead {
  font-size: 1.1rem;
  color: var(--ink-soft);
  max-width: 46ch;
}

.muted {
  color: var(--ink-soft);
  font-size: .92rem;
}

/* Hero */
.hero {
  padding: 64px 0 60px;
  display: grid;
  grid-template-columns: 1.15fr .85fr;
  gap: 40px;
  align-items: center;
}

.hero-art {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 22px;
  padding: 14px;
  box-shadow: 0 16px 40px -24px rgba(20, 28, 63, .5);
}

.hero-art img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: 12px;
}

.hero-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-top: 26px;
}

.btn {
  display: inline-block;
  padding: 11px 22px;
  border-radius: 10px;
  background: var(--accent);
  color: #fff;
  text-decoration: none;
  font-size: .95rem;
  font-weight: 600;
  border: 1px solid var(--accent);
  transition: background .15s ease, border-color .15s ease;
}

.btn:hover {
  background: var(--accent-dark);
  border-color: var(--accent-dark);
}

.btn-ghost {
  background: var(--surface);
  color: var(--ink);
  border-color: var(--line);
}

.btn-ghost:hover {
  background: var(--accent-soft);
  border-color: var(--accent-soft);
  color: var(--accent-dark);
}

/* Code */
pre {
  background: var(--slate-deep);
  border: 1px solid var(--slate);
  border-radius: 12px;
  padding: 16px 18px;
  overflow-x: auto;
  font-size: .88rem;
  line-height: 1.7;
  margin: 0 0 16px;
}

pre code { color: #e6eaf5; }

:not(pre) > code {
  background: var(--accent-soft);
  color: var(--accent-dark);
  border-radius: 5px;
  padding: 1px 5px;
  font-size: .88em;
}

/* Steps */
.steps {
  margin: 0;
  padding-left: 20px;
}

.steps li { margin-bottom: 10px; }
.steps li::marker { color: var(--accent); font-weight: 700; }

/* Cards */
.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 14px;
}

.card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-top: 3px solid var(--accent);
  border-radius: 12px;
  padding: 18px 20px;
}

.card p {
  margin: 0;
  color: var(--ink-soft);
  font-size: .92rem;
}

/* Footer */
footer {
  background: var(--slate-deep);
  color: #b9c1d6;
  margin-top: 24px;
}

.footer-inner {
  max-width: 940px;
  margin: 0 auto;
  padding: 30px 24px 40px;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 20px;
  margin-bottom: 16px;
  font-size: .85rem;
}

.footer-links a {
  color: #d3d9e8;
  text-decoration: none;
}

.footer-links a:hover { color: #7aa4ff; }

.fineprint {
  font-size: .78rem;
  color: #9aa3bb;
  max-width: 70ch;
  line-height: 1.6;
  margin: 0 0 8px;
}

.fineprint strong { color: #d3d9e8; }

/* ------------------------------------------------------------- Download */
.hero-note {
  margin: 14px 0 0;
  font-size: .85rem;
  color: var(--ink-soft);
}

.btn-lg {
  padding: 15px 30px;
  font-size: 1.05rem;
  border-radius: 12px;
}

.download {
  display: grid;
  grid-template-columns: 1.15fr .85fr;
  gap: 22px;
  align-items: stretch;
  margin-top: 22px;
}

.download-main,
.download-side {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 26px;
  /* Grid items default to min-width:auto, which lets the code block inside
     push the whole page wider than the viewport on narrow screens. */
  min-width: 0;
}

.download-main {
  border-top: 3px solid var(--accent);
}

.download-kicker {
  margin: 0 0 6px;
  font-size: .72rem;
  font-weight: 700;
  letter-spacing: .09em;
  text-transform: uppercase;
  color: var(--accent);
}

.download-main h3 {
  margin: 0 0 10px;
  font-size: 1.5rem;
  color: var(--ink);
}

.download-sub {
  margin: 0 0 22px;
  color: var(--ink-soft);
  max-width: 44ch;
}

.download-meta {
  margin: 16px 0 0;
  font-size: .82rem;
  color: var(--ink-soft);
}

.download-side p {
  margin: 0 0 12px;
  font-size: .9rem;
  color: var(--ink-soft);
}

.download-side strong { color: var(--ink); }

.download-verify { margin-top: 18px; }

.download-side pre {
  margin: 0;
  font-size: .78rem;
  padding: 12px 14px;
}

.alt-install {
  margin-top: 26px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--surface);
}

.alt-install summary {
  cursor: pointer;
  padding: 14px 20px;
  font-size: .92rem;
  font-weight: 600;
  color: var(--ink);
  list-style: none;
}

.alt-install summary::-webkit-details-marker { display: none; }

.alt-install summary::before {
  content: "＋";
  margin-right: 10px;
  color: var(--accent);
  font-weight: 700;
}

.alt-install[open] summary::before { content: "－"; }

.alt-install summary:hover { color: var(--accent-dark); }

.alt-install-body {
  padding: 0 20px 18px;
  border-top: 1px solid var(--line);
  font-size: .92rem;
}

.alt-install-body p:first-child { margin-top: 16px; }

@media (max-width: 720px) {
  .hero {
    grid-template-columns: 1fr;
    padding-top: 44px;
  }
  .hero-art { order: -1; max-width: 320px; }
  .download { grid-template-columns: 1fr; }
  .btn-lg {
    display: block;
    text-align: center;
    padding: 15px 20px;
  }
}

/* ------------------------------------------------------------- Legal page */
.legal { max-width: 68ch; }
.legal .crumb { font-size: 0.9rem; color: var(--ink-soft); margin: 0 0 18px; }
.legal h2 {
  font-size: 1.15rem;
  margin: 34px 0 10px;
  scroll-margin-top: 24px;
}
.legal h2:first-of-type { margin-top: 26px; }
.legal p { margin: 0 0 14px; }


/* ----------------------------------------------------------------- 404 page */
.nf-wrap {
  min-height: 100vh;
  display: grid;
  place-items: center;
  text-align: center;
  padding: 3rem 1.5rem;
  position: relative;
  z-index: 1;
}
.nf-inner { max-width: 46ch; }
.nf-inner img { width: 76px; height: auto; margin: 0 auto 26px; }
.nf-code {
  font-size: clamp(4.5rem, 17vw, 8.5rem);
  font-weight: 800;
  line-height: 1;
  letter-spacing: -0.04em;
  margin: 0;
  opacity: 0.13;
}
.nf-inner h1 { font-size: clamp(1.5rem, 4.5vw, 2.1rem); margin: -0.3em 0 0.6rem; }
.nf-inner p { margin: 0 0 1.9rem; opacity: 0.75; }