/* HeartBeat site — the app's own visual language, translated to the web.
   Forced dark, one hue per track, cyan reserved for MIDI-learn, amber for locks,
   square corners. Colors sampled from HeartBeat/Theme.swift. */

:root {
  --bg: rgb(5, 5, 8);
  --surface: rgb(33, 33, 42);
  --elevated: rgb(18, 18, 23);
  --step-off: rgb(42, 42, 52);
  --step-accent: rgb(60, 60, 74);
  --hairline: rgba(255, 255, 255, 0.16);
  --hairline-soft: rgba(255, 255, 255, 0.08);
  --amber: rgb(255, 191, 38);
  --cyan: rgb(51, 230, 255);
  --red: rgb(255, 61, 61);
  --violet: rgb(194, 143, 255);
  --text: rgba(255, 255, 255, 0.92);
  --text-dim: rgba(255, 255, 255, 0.55);
  --text-faint: rgba(255, 255, 255, 0.35);

  /* The default track sweep (Theme.defaultTrackSlots) */
  --t0: rgb(235, 74, 65);   --t1: rgb(229, 116, 46);  --t2: rgb(242, 169, 72);
  --t3: rgb(252, 241, 94);  --t4: rgb(203, 249, 79);  --t5: rgb(103, 192, 57);
  --t6: rgb(122, 251, 175); --t7: rgb(86, 188, 175);  --t8: rgb(109, 230, 252);
  --t9: rgb(75, 162, 232);  --t10: rgb(54, 123, 187); --t11: rgb(132, 109, 221);
  --t12: rgb(202, 114, 222);--t13: rgb(235, 76, 206); --t14: rgb(212, 93, 158);
  --t15: rgb(240, 153, 167);

  --r: 4px;           /* the app's squared-up corner */
  --r-panel: 6px;
  --font: -apple-system, "SF Pro Text", system-ui, "Segoe UI", Roboto, sans-serif;
  --mono: ui-monospace, "SF Mono", SFMono-Regular, Menlo, Consolas, monospace;
}

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

html { scroll-behavior: smooth; }

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

::selection { background: rgba(51, 230, 255, 0.25); }

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

code {
  font-family: var(--mono);
  font-size: 0.85em;
  background: var(--surface);
  border: 1px solid var(--hairline-soft);
  border-radius: 3px;
  padding: 0.1em 0.4em;
}

/* ---------- chrome shared by every page ---------- */

.topbar {
  position: sticky;
  top: 0;
  z-index: 50;
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 12px 22px;
  background: rgba(5, 5, 8, 0.88);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--hairline-soft);
}

.topbar .wordmark {
  font-weight: 800;
  font-size: 17px;
  letter-spacing: 0.02em;
  color: var(--text);
}
.topbar .wordmark:hover { text-decoration: none; }
.topbar .wordmark .beat { color: var(--red); }

.topbar nav { margin-left: auto; display: flex; gap: 18px; }
.topbar nav a {
  color: var(--text-dim);
  font-size: 13.5px;
  font-weight: 600;
}
.topbar nav a:hover { color: var(--text); text-decoration: none; }
.topbar nav a.active { color: var(--text); }

/* The 16-track rainbow hairline — the site's signature stripe. */
.trackstripe {
  height: 3px;
  background: linear-gradient(90deg,
    var(--t0) 0 6.25%,  var(--t1) 0 12.5%,  var(--t2) 0 18.75%, var(--t3) 0 25%,
    var(--t4) 0 31.25%, var(--t5) 0 37.5%,  var(--t6) 0 43.75%, var(--t7) 0 50%,
    var(--t8) 0 56.25%, var(--t9) 0 62.5%,  var(--t10) 0 68.75%, var(--t11) 0 75%,
    var(--t12) 0 81.25%, var(--t13) 0 87.5%, var(--t14) 0 93.75%, var(--t15) 0 100%);
}

footer {
  margin-top: 80px;
  padding: 28px 22px 40px;
  border-top: 1px solid var(--hairline-soft);
  color: var(--text-faint);
  font-size: 13px;
  text-align: center;
}
footer a { color: var(--text-dim); }

/* ---------- landing ---------- */

.hero {
  max-width: 980px;
  margin: 0 auto;
  padding: 84px 22px 40px;
  text-align: center;
}

.hero h1 {
  font-size: clamp(42px, 8vw, 76px);
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.05;
}
.hero h1 .beat { color: var(--red); }

.hero .tagline {
  margin: 18px auto 0;
  max-width: 620px;
  font-size: clamp(17px, 2.6vw, 21px);
  color: var(--text-dim);
}

.hero .cta-row {
  margin-top: 34px;
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
}

.btn-beta {
  display: inline-flex;
  align-items: center;
  padding: 12px 20px;
  background: var(--red);
  color: #fff !important;
  border-radius: var(--r);
  font-weight: 700;
  font-size: 14px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}
.btn-beta:hover { text-decoration: none; opacity: 0.85; }

.hero .cta-note {
  margin-top: 14px;
  font-size: 14px;
  color: var(--text-faint);
}

.btn-manual {
  display: inline-flex;
  align-items: center;
  padding: 12px 20px;
  background: var(--text);
  color: var(--bg) !important;
  border-radius: var(--r);
  font-weight: 700;
  font-size: 14px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}
.btn-manual:hover { text-decoration: none; opacity: 0.85; }

.section {
  max-width: 980px;
  margin: 0 auto;
  padding: 48px 22px;
}

.section h2 {
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--text-faint);
  margin-bottom: 22px;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 14px;
}

.feature {
  background: var(--elevated);
  border: 1px solid var(--hairline-soft);
  border-left: 3px solid var(--accent, var(--t8));
  border-radius: var(--r-panel);
  padding: 18px 18px 16px;
}
.feature h3 { font-size: 16px; font-weight: 700; margin-bottom: 6px; }
.feature p { font-size: 14px; color: var(--text-dim); }
.feature a { font-size: 13px; font-weight: 600; }

/* ---------- screenshots ---------- */

.phone {
  max-width: 340px;
  margin: 46px auto 0;
  border: 1px solid var(--hairline);
  border-radius: 34px;
  padding: 10px;
  background: var(--elevated);
  box-shadow: 0 30px 80px rgba(0, 0, 0, 0.6);
}
.phone img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: 26px;
}

.shot {
  display: block;
  width: min(320px, 100%);
  height: auto;
  margin: 20px auto;
  border: 1px solid var(--hairline-soft);
  border-radius: 14px;
}
.shot-row {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
  justify-content: center;
  margin: 20px 0;
}
.shot-row .shot { margin: 0; flex: 0 1 240px; }
/* A sideways-phone capture: full column width, gentler corners. */
.shot.wide { width: 100%; max-width: 860px; border-radius: 10px; }
.phone.wide { max-width: 900px; border-radius: 26px; }
.phone.wide img { border-radius: 18px; }

/* ---------- manual layout ---------- */

.manual {
  display: grid;
  grid-template-columns: 230px minmax(0, 1fr);
  gap: 40px;
  max-width: 1080px;
  margin: 0 auto;
  padding: 34px 22px 60px;
}

.manual aside {
  position: sticky;
  top: 76px;
  align-self: start;
  font-size: 13.5px;
}
.manual aside .group {
  font-size: 10.5px;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-faint);
  margin: 18px 0 6px;
}
.manual aside a {
  display: block;
  color: var(--text-dim);
  padding: 4px 10px;
  border-left: 2px solid transparent;
  font-weight: 600;
}
.manual aside a:hover { color: var(--text); text-decoration: none; }
.manual aside a.here {
  color: var(--text);
  border-left-color: var(--accent, var(--cyan));
  background: linear-gradient(90deg, rgba(255,255,255,0.05), transparent);
}

.manual article { min-width: 0; }

.manual article h1 {
  font-size: 34px;
  font-weight: 800;
  letter-spacing: -0.01em;
  margin-bottom: 6px;
}
.manual article .lede {
  color: var(--text-dim);
  font-size: 17px;
  margin-bottom: 30px;
  max-width: 62ch;
}
.manual article h2 {
  font-size: 22px;
  font-weight: 800;
  margin: 44px 0 12px;
  padding-top: 18px;
  border-top: 1px solid var(--hairline-soft);
}
.manual article h2:first-of-type { border-top: none; padding-top: 0; }
.manual article h3 {
  font-size: 16px;
  font-weight: 700;
  margin: 26px 0 8px;
}
.manual article p { margin: 10px 0; max-width: 70ch; }
.manual article ul, .manual article ol { margin: 10px 0 10px 22px; max-width: 66ch; }
.manual article li { margin: 5px 0; }

/* a physical control / button name */
.key {
  display: inline-block;
  font-size: 0.8em;
  font-weight: 800;
  letter-spacing: 0.05em;
  background: var(--surface);
  border: 1px solid var(--hairline);
  border-bottom-width: 2px;
  border-radius: 3px;
  padding: 0.05em 0.5em;
  vertical-align: 0.05em;
}
.key.amber { color: var(--amber); }
.key.cyan { color: var(--cyan); }
.key.red { color: var(--red); }

/* callouts */
.tip, .note {
  border-radius: var(--r-panel);
  border: 1px solid var(--hairline-soft);
  padding: 12px 16px;
  margin: 16px 0;
  font-size: 14.5px;
  max-width: 70ch;
  background: var(--elevated);
}
.tip { border-left: 3px solid var(--t6); }
.note { border-left: 3px solid var(--amber); }
.tip strong:first-child, .note strong:first-child {
  text-transform: uppercase;
  font-size: 11px;
  letter-spacing: 0.1em;
  display: block;
  margin-bottom: 3px;
  color: var(--text-dim);
}

/* parameter tables */
table {
  width: 100%;
  border-collapse: collapse;
  margin: 14px 0 22px;
  font-size: 14px;
}
th {
  text-align: left;
  font-size: 10.5px;
  font-weight: 800;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-faint);
  padding: 6px 12px;
  border-bottom: 1px solid var(--hairline);
}
td {
  padding: 7px 12px;
  border-bottom: 1px solid var(--hairline-soft);
  vertical-align: top;
}
td:first-child {
  font-family: var(--mono);
  font-size: 12.5px;
  font-weight: 700;
  white-space: nowrap;
}
td:last-child { color: var(--text-dim); }
.tablewrap { overflow-x: auto; }

/* page-turn footer nav */
.pagenav {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  margin-top: 56px;
  padding-top: 18px;
  border-top: 1px solid var(--hairline-soft);
}
.pagenav a {
  background: var(--elevated);
  border: 1px solid var(--hairline-soft);
  border-radius: var(--r);
  padding: 12px 16px;
  font-weight: 700;
  font-size: 14px;
  color: var(--text);
  flex: 0 1 auto;
}
.pagenav a small {
  display: block;
  font-weight: 600;
  font-size: 10.5px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-faint);
}
.pagenav a:hover { text-decoration: none; border-color: var(--hairline); }
.pagenav .next { margin-left: auto; text-align: right; }

@media (max-width: 760px) {
  .manual { grid-template-columns: 1fr; gap: 8px; }
  .manual aside {
    position: static;
    display: flex;
    flex-wrap: wrap;
    gap: 2px 10px;
    padding-bottom: 14px;
    border-bottom: 1px solid var(--hairline-soft);
  }
  .manual aside .group { width: 100%; margin: 8px 0 2px; }
  .manual aside a { border-left: none; padding: 2px 4px; }
}