/* ── Reset & base ────────────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg:        #F2F2F0;   /* piano roll canvas */
  --surface:   #F7F7F5;   /* white key rows */
  --border:    #C0C0BE;   /* bar grid lines */
  --border-lt: #E0E0DE;   /* beat grid lines */
  --text:      #232320;   /* transport bar / dark chrome */
  --muted:     #888886;   /* piano key labels */
  --chrome:    #232320;   /* nav background */
  --chrome-sub:#383836;   /* transport bottom separator */
  --chrome-txt:#DEDEDC;   /* text on dark chrome */
  --accent:    #CC8800;   /* amber — loop handles, draw preview */
  --accent-dk: #AA6600;
  --code-bg:   #ECECEA;   /* black key rows */
  --radius:    6px;
  --mono: "DM Mono", "Menlo", "Consolas", monospace;
  --sans: "Inter", system-ui, sans-serif;
}

html { scroll-behavior: smooth; }

body {
  font-family: var(--sans);
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}

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

code {
  font-family: var(--mono);
  font-size: 0.87em;
  background: var(--code-bg);
  padding: 2px 6px;
  border-radius: 4px;
  color: var(--text);
}

/* ── Layout ─────────────────────────────────────────────────────────────── */
.section-inner {
  max-width: 680px;
  margin: 0 auto;
  padding: 0 32px;
}

/* ── Nav ────────────────────────────────────────────────────────────────── */
nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--chrome);
  border-bottom: 1px solid var(--chrome-sub);
}
.nav-inner {
  max-width: 680px;
  margin: 0 auto;
  padding: 0 32px;
  height: 40px;
  display: flex;
  align-items: center;
}
.wordmark {
  font-weight: 500;
  font-size: 13px;
  color: var(--chrome-txt);
  letter-spacing: 0.01em;
}
.wordmark:hover { text-decoration: none; color: #fff; }

/* ── Hero ───────────────────────────────────────────────────────────────── */
.hero {
  padding: 80px 0 64px;
}
.hero-inner {
  position: relative;
  z-index: 1;
}
.badge {
  display: inline-block;
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
  border: 1px solid var(--accent);
  border-radius: 100px;
  padding: 2px 9px;
  margin-bottom: 20px;
}
h1 {
  font-size: clamp(2.2rem, 5vw, 3.4rem);
  font-weight: 300;
  line-height: 1.1;
  letter-spacing: -0.03em;
  margin-bottom: 20px;
  color: var(--text);
}
.hero-sub {
  font-size: 1rem;
  color: var(--muted);
  font-weight: 400;
}

/* ── Download section ───────────────────────────────────────────────────── */
.install {
  padding: 64px 0;
  border-top: 1px solid var(--border);
}
.install h2, .about h2 {
  font-size: 1.4rem;
  font-weight: 400;
  letter-spacing: -0.01em;
  margin-bottom: 24px;
  color: var(--text);
}

.download-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin-bottom: 32px;
}
.download-card {
  display: flex;
  flex-direction: column;
  gap: 5px;
  padding: 20px 18px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  text-decoration: none !important;
  transition: border-color 0.12s;
}
.download-card:hover { border-color: var(--text); }
.dl-platform { font-size: 14px; font-weight: 600; color: var(--text); }
.dl-detail   { font-size: 11px; color: var(--muted); line-height: 1.4; }
.dl-cta      { margin-top: 10px; font-size: 12px; font-weight: 500; color: var(--accent); }

/* ── CSS-only tabs ──────────────────────────────────────────────────────── */
#tab-mac, #tab-win { display: none; }

.tab-labels {
  display: flex;
  gap: 0;
  margin-bottom: 20px;
  border-bottom: 1px solid var(--border);
}
.tab-label {
  font-size: 13px;
  font-weight: 500;
  padding: 6px 14px;
  cursor: pointer;
  color: var(--muted);
  border-bottom: 2px solid transparent;
  margin-bottom: -1px;
  transition: color 0.12s;
}
.tab-label:hover { color: var(--text); }

#tab-mac:checked ~ .tab-labels label[for="tab-mac"],
#tab-win:checked ~ .tab-labels label[for="tab-win"] {
  color: var(--text);
  border-bottom-color: var(--text);
}

.tab-content { display: none; }
#tab-mac:checked ~ #content-mac,
#tab-win:checked ~ #content-win { display: block; }

/* ── Step list ──────────────────────────────────────────────────────────── */
.run-steps {
  list-style: decimal;
  padding-left: 20px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.run-steps li {
  font-size: 14px;
  color: var(--muted);
  line-height: 1.6;
}
.run-steps pre { margin-top: 8px; }

pre {
  background: var(--code-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 12px 14px;
  overflow-x: auto;
}
pre code {
  background: none;
  padding: 0;
  font-size: 12.5px;
  line-height: 1.7;
}

/* ── About ──────────────────────────────────────────────────────────────── */
.about {
  padding: 64px 0;
  border-top: 1px solid var(--border);
}
.about p {
  font-size: 14px;
  color: var(--muted);
  margin-bottom: 14px;
  line-height: 1.75;
}
.small-note { font-size: 12px !important; }

/* ── Footer ─────────────────────────────────────────────────────────────── */
footer {
  background: var(--chrome);
  border-top: 1px solid var(--chrome-sub);
  padding: 20px 0;
}
.footer-inner {
  max-width: 680px;
  margin: 0 auto;
  padding: 0 32px;
}
.footer-wordmark { font-size: 12px; color: #888886; font-weight: 500; }

/* ── Responsive ─────────────────────────────────────────────────────────── */
@media (max-width: 520px) {
  .hero { padding: 48px 0 40px; }
  h1 { font-size: 2rem; }
  .download-grid { grid-template-columns: 1fr; }
}