/* =============================================================
   The Cardiac Dance — Rhythm City
   Design system & global styles
   ============================================================= */

/* ---------- Fonts ---------- */
@import url('https://fonts.googleapis.com/css2?family=Space+Grotesk:wght@400;500;600;700&family=Inter:wght@400;450;500;600;700&display=swap');

/* ---------- Design tokens ---------- */
:root {
  /* base surfaces */
  --ink:            #070A12;
  --bg:             #0B0F1A;
  --bg-2:           #0E1322;
  --surface:        #131A2B;
  --surface-2:      #1A2236;
  --surface-3:      #222C44;
  --line:           #2A3650;
  --line-soft:      #1F293F;

  /* text */
  --text:           #EAEEF7;
  --text-soft:      #AEB8CE;
  --text-mute:      #7C879F;

  /* signature ECG green */
  --ecg:            #34E7A6;
  --ecg-bright:     #5CFFC2;
  --ecg-deep:       #0E2C24;
  --ecg-glow:       rgba(52, 231, 166, 0.55);

  /* venue accents */
  --neon-pink:      #FF5C8A;
  --neon-violet:    #9D7BFF;
  --neon-amber:     #FFB454;
  --neon-cyan:      #46D4FF;

  /* rhythm family colors */
  --fam-sinus:      #34E7A6;
  --fam-atrial:     #9D7BFF;
  --fam-junctional: #FFB454;
  --fam-ventricular:#FF5C6C;
  --fam-block:      #46D4FF;
  --fam-pacemaker:  #6EE7E0;
  --fam-advanced:   #FF5C8A;
  --fam-artifact:   #8B97B2;

  /* status */
  --danger:         #FF5C6C;
  --warn:           #FFB454;
  --ok:             #34E7A6;

  /* layout */
  --maxw:           1180px;
  --radius:         16px;
  --radius-sm:      10px;
  --radius-lg:      26px;

  /* type */
  --font-head: 'Space Grotesk', 'Segoe UI', system-ui, sans-serif;
  --font-body: 'Inter', 'Segoe UI', system-ui, -apple-system, sans-serif;

  --shadow:    0 24px 60px -28px rgba(0,0,0,0.85);
  --shadow-sm: 0 10px 28px -16px rgba(0,0,0,0.8);
}

/* ---------- Reset ---------- */
* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  font-family: var(--font-body);
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  font-size: 16.5px;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
  font-weight: 450;
}
img, svg, canvas { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button { font-family: inherit; cursor: pointer; border: none; background: none; color: inherit; }
input, select, textarea { font-family: inherit; }
ul { list-style: none; }

/* page background ambience */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  background:
    radial-gradient(680px 420px at 12% -6%, rgba(52,231,166,0.10), transparent 70%),
    radial-gradient(720px 480px at 92% 4%, rgba(157,123,255,0.11), transparent 72%),
    radial-gradient(900px 600px at 50% 108%, rgba(255,92,138,0.07), transparent 70%);
}

/* ---------- Typography ---------- */
h1, h2, h3, h4 { font-family: var(--font-head); font-weight: 600; line-height: 1.18; letter-spacing: -0.018em; }
h1 { font-size: clamp(2.3rem, 5.4vw, 4rem); font-weight: 700; }
h2 { font-size: clamp(1.7rem, 3.4vw, 2.5rem); }
h3 { font-size: clamp(1.2rem, 2vw, 1.5rem); }
p  { color: var(--text-soft); }
strong { color: var(--text); font-weight: 600; }

.eyebrow {
  font-family: var(--font-head);
  text-transform: uppercase;
  letter-spacing: 0.22em;
  font-size: 0.72rem;
  font-weight: 600;
  color: var(--ecg);
  display: inline-flex;
  align-items: center;
  gap: 9px;
}
.eyebrow::before {
  content: "";
  width: 26px; height: 2px;
  background: linear-gradient(90deg, var(--ecg), transparent);
}

.grad-text {
  background: linear-gradient(108deg, var(--ecg-bright) 8%, var(--neon-cyan) 48%, var(--neon-violet) 92%);
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* ---------- Layout ---------- */
.wrap { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 26px; position: relative; z-index: 1; }
.section { padding: 84px 0; position: relative; z-index: 1; }
.section-tight { padding: 52px 0; }
main { position: relative; z-index: 1; min-height: 60vh; }

.section-head { max-width: 660px; margin-bottom: 40px; }
.section-head.center { margin-left: auto; margin-right: auto; text-align: center; }
.section-head h2 { margin: 14px 0 12px; }
.section-head p { font-size: 1.05rem; }

/* ============================================================
   Navigation
   ============================================================ */
.site-header {
  position: sticky; top: 0; z-index: 100;
  background: rgba(11,15,26,0.82);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--line-soft);
}
.nav {
  display: flex; align-items: center; justify-content: space-between;
  height: 70px;
}
.brand { display: flex; align-items: center; gap: 11px; font-family: var(--font-head); font-weight: 700; font-size: 1.08rem; letter-spacing: -0.02em; }
.brand .mark {
  width: 38px; height: 38px; border-radius: 11px;
  background: linear-gradient(150deg, var(--surface-2), var(--ink));
  border: 1px solid var(--line);
  display: grid; place-items: center;
  flex-shrink: 0;
  position: relative; overflow: hidden;
}
.brand .mark svg { width: 26px; height: 26px; }
.brand .mark::after {
  content:""; position:absolute; inset:0;
  box-shadow: inset 0 0 16px rgba(52,231,166,0.25);
}
.brand small { display: block; font-family: var(--font-body); font-weight: 500; font-size: 0.66rem; letter-spacing: 0.16em; text-transform: uppercase; color: var(--text-mute); margin-top: -3px; }

.nav-links { display: flex; align-items: center; gap: 4px; }
.nav-links a {
  padding: 9px 15px; border-radius: 9px;
  font-size: 0.92rem; font-weight: 500; color: var(--text-soft);
  transition: color .15s, background .15s;
}
.nav-links a:hover { color: var(--text); background: var(--surface); }
.nav-links a.active { color: var(--ecg); background: var(--ecg-deep); }

.nav-cta {
  padding: 9px 18px !important;
  background: var(--ecg) !important;
  color: var(--ink) !important;
  font-weight: 600 !important;
  border-radius: 9px;
}
.nav-cta:hover { background: var(--ecg-bright) !important; }

.nav-toggle { display: none; width: 42px; height: 42px; border-radius: 10px; border: 1px solid var(--line); }
.nav-toggle span, .nav-toggle span::before, .nav-toggle span::after {
  display: block; width: 18px; height: 2px; background: var(--text); border-radius: 2px;
  position: relative; margin: 0 auto; transition: .2s;
}
.nav-toggle span::before, .nav-toggle span::after { content: ""; position: absolute; left: 0; }
.nav-toggle span::before { top: -6px; }
.nav-toggle span::after { top: 6px; }

/* ============================================================
   Buttons
   ============================================================ */
.btn {
  display: inline-flex; align-items: center; gap: 9px;
  padding: 13px 24px; border-radius: 11px;
  font-family: var(--font-head); font-weight: 600; font-size: 0.95rem;
  transition: transform .14s ease, box-shadow .2s, background .2s;
  white-space: nowrap;
}
.btn:active { transform: translateY(1px); }
.btn-primary { background: var(--ecg); color: var(--ink); box-shadow: 0 14px 34px -16px var(--ecg-glow); }
.btn-primary:hover { background: var(--ecg-bright); box-shadow: 0 18px 40px -14px var(--ecg-glow); }
.btn-ghost { background: var(--surface); color: var(--text); border: 1px solid var(--line); }
.btn-ghost:hover { background: var(--surface-2); border-color: var(--surface-3); }
.btn-lg { padding: 16px 30px; font-size: 1.02rem; }
.btn svg { width: 18px; height: 18px; }

/* ============================================================
   Cards & generic surfaces
   ============================================================ */
.card {
  background: var(--surface);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  transition: transform .18s ease, border-color .18s, box-shadow .18s;
}
.panel {
  background: linear-gradient(180deg, var(--surface), var(--bg-2));
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-lg);
}

.tag {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 4px 11px; border-radius: 999px;
  font-size: 0.72rem; font-weight: 600; letter-spacing: 0.04em;
  font-family: var(--font-head);
  border: 1px solid var(--line);
  color: var(--text-soft);
  text-transform: uppercase;
}
.tag .dot { width: 7px; height: 7px; border-radius: 50%; background: currentColor; }

/* ============================================================
   ECG monitor display
   ============================================================ */
.monitor {
  position: relative;
  background:
    radial-gradient(120% 140% at 50% 0%, #0c1c18 0%, #060b0c 75%);
  border: 1px solid #1d3b33;
  border-radius: 14px;
  overflow: hidden;
}
.monitor canvas { display: block; width: 100%; }
.monitor::after {
  content: "";
  position: absolute; inset: 0;
  pointer-events: none;
  box-shadow: inset 0 0 60px rgba(0,0,0,0.6);
  border-radius: 14px;
}
.monitor-label {
  position: absolute; top: 9px; left: 12px;
  font-family: var(--font-head); font-size: 0.66rem; font-weight: 600;
  letter-spacing: 0.16em; text-transform: uppercase;
  color: var(--ecg); opacity: 0.85;
  display: flex; align-items: center; gap: 7px;
}
.monitor-label .live { width: 7px; height: 7px; border-radius: 50%; background: var(--ecg); animation: blip 1.05s infinite; }
@keyframes blip { 0%,100%{opacity:1} 50%{opacity:0.25} }
.monitor-rate {
  position: absolute; top: 8px; right: 12px;
  font-family: var(--font-head); font-weight: 700;
  color: var(--ecg-bright);
  font-size: 1.05rem; line-height: 1;
}
.monitor-rate small { font-size: 0.58rem; letter-spacing: 0.12em; color: var(--text-mute); display:block; text-align:right; font-weight:600; }

/* pause / play control on each monitor */
.mon-toggle {
  position: absolute; bottom: 8px; right: 8px; z-index: 5;
  width: 27px; height: 27px; border-radius: 50%; padding: 0;
  background: rgba(7,12,11,0.74);
  border: 1px solid rgba(52,231,166,0.4);
  display: grid; place-items: center;
  color: var(--ecg);
  opacity: 0.6;
  transition: opacity .15s, background .15s, transform .12s;
}
.monitor:hover .mon-toggle { opacity: 1; }
.mon-toggle:hover { background: rgba(7,12,11,0.96); transform: scale(1.09); }
.mon-toggle:active { transform: scale(0.95); }
.mon-toggle svg { width: 12px; height: 12px; }
.mon-toggle.is-paused { opacity: 1; border-color: var(--ecg); background: rgba(52,231,166,0.18); }

/* ============================================================
   Footer
   ============================================================ */
.site-footer {
  border-top: 1px solid var(--line-soft);
  background: var(--ink);
  padding: 56px 0 30px;
  position: relative; z-index: 1;
  margin-top: 40px;
}
.footer-grid {
  display: grid; grid-template-columns: 1.6fr 1fr 1fr 1fr; gap: 36px;
  margin-bottom: 38px;
}
.footer-grid h4 { font-size: 0.78rem; text-transform: uppercase; letter-spacing: 0.14em; color: var(--text-mute); margin-bottom: 14px; font-family: var(--font-body); }
.footer-grid a { display: block; color: var(--text-soft); font-size: 0.92rem; padding: 5px 0; transition: color .15s; }
.footer-grid a:hover { color: var(--ecg); }
.footer-blurb { color: var(--text-mute); font-size: 0.9rem; max-width: 290px; margin-top: 14px; }
.footer-bottom {
  border-top: 1px solid var(--line-soft);
  padding-top: 22px;
  display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap;
  color: var(--text-mute); font-size: 0.82rem;
}
.footer-disclaimer {
  background: var(--surface);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-sm);
  padding: 14px 18px;
  font-size: 0.8rem; color: var(--text-mute);
  margin-bottom: 30px;
}
.footer-disclaimer strong { color: var(--text-soft); }

/* ============================================================
   Callout boxes (book components)
   ============================================================ */
.callout {
  border-radius: var(--radius);
  padding: 22px 24px;
  margin: 26px 0;
  border: 1px solid var(--line);
  background: var(--surface);
  position: relative;
}
.callout-head {
  display: flex; align-items: center; gap: 10px;
  font-family: var(--font-head); font-weight: 600; font-size: 0.96rem;
  margin-bottom: 10px;
}
.callout-head .ico { font-size: 1.1rem; }
.callout p { font-size: 0.96rem; }
.callout p + p { margin-top: 9px; }
.callout ul.bul { margin-top: 8px; }
.callout ul.bul li {
  position: relative; padding-left: 20px; margin: 7px 0;
  font-size: 0.95rem; color: var(--text-soft);
}
.callout ul.bul li::before {
  content: ""; position: absolute; left: 2px; top: 10px;
  width: 7px; height: 7px; border-radius: 2px; background: currentColor; opacity: 0.6;
}

.callout.mansion { border-color: rgba(110,231,224,0.32); background: linear-gradient(180deg, rgba(110,231,224,0.07), var(--surface)); }
.callout.mansion .callout-head { color: var(--fam-pacemaker); }
.callout.warn { border-color: rgba(255,180,84,0.34); background: linear-gradient(180deg, rgba(255,180,84,0.07), var(--surface)); }
.callout.warn .callout-head { color: var(--warn); }
.callout.heart { border-color: rgba(255,92,108,0.34); background: linear-gradient(180deg, rgba(255,92,108,0.07), var(--surface)); }
.callout.heart .callout-head { color: var(--danger); }
.callout.music { border-color: rgba(157,123,255,0.34); background: linear-gradient(180deg, rgba(157,123,255,0.07), var(--surface)); }
.callout.music .callout-head { color: var(--neon-violet); }
.callout.pro { border-color: rgba(70,212,255,0.34); background: linear-gradient(180deg, rgba(70,212,255,0.07), var(--surface)); }
.callout.pro .callout-head { color: var(--neon-cyan); }
.callout.dont { border-color: rgba(255,92,138,0.32); background: linear-gradient(180deg, rgba(255,92,138,0.06), var(--surface)); }
.callout.dont .callout-head { color: var(--neon-pink); }

/* ============================================================
   Tables
   ============================================================ */
.tbl-wrap { overflow-x: auto; border-radius: var(--radius); border: 1px solid var(--line-soft); margin: 22px 0; }
table.data {
  width: 100%; border-collapse: collapse; font-size: 0.9rem;
  background: var(--surface);
}
table.data th, table.data td { padding: 12px 15px; text-align: left; border-bottom: 1px solid var(--line-soft); }
table.data th {
  font-family: var(--font-head); font-weight: 600; font-size: 0.76rem;
  text-transform: uppercase; letter-spacing: 0.07em; color: var(--text-mute);
  background: var(--bg-2);
}
table.data td { color: var(--text-soft); vertical-align: top; }
table.data tr:last-child td { border-bottom: none; }
table.data tbody tr:hover { background: var(--surface-2); }
table.data td strong { color: var(--text); }

/* ============================================================
   Generic prose block
   ============================================================ */
.prose p { margin: 14px 0; }
.prose h3 { margin: 30px 0 10px; color: var(--text); }
.prose h4 { margin: 22px 0 8px; color: var(--ecg); font-size: 1.04rem; }
.prose ul.bul li { position: relative; padding-left: 22px; margin: 8px 0; color: var(--text-soft); }
.prose ul.bul li::before {
  content: ""; position: absolute; left: 3px; top: 11px;
  width: 7px; height: 7px; border-radius: 2px;
  background: var(--ecg); opacity: 0.8;
}
.prose em { color: var(--text); font-style: italic; }

/* speaker lines (Dr. Pulse / RhythmBot) */
.speaker {
  display: flex; gap: 14px; align-items: flex-start;
  background: var(--surface); border: 1px solid var(--line-soft);
  border-radius: var(--radius); padding: 18px 20px; margin: 22px 0;
}
.speaker .avatar {
  width: 44px; height: 44px; border-radius: 12px; flex-shrink: 0;
  display: grid; place-items: center; font-size: 1.4rem;
  border: 1px solid var(--line);
}
.speaker.pulse .avatar { background: rgba(70,212,255,0.12); border-color: rgba(70,212,255,0.3); }
.speaker.bot .avatar { background: rgba(52,231,166,0.12); border-color: rgba(52,231,166,0.3); }
.speaker .who { font-family: var(--font-head); font-weight: 600; font-size: 0.9rem; margin-bottom: 2px; }
.speaker.pulse .who { color: var(--neon-cyan); }
.speaker.bot .who { color: var(--ecg); }
.speaker p { font-size: 0.96rem; font-style: italic; margin: 0; }

/* ============================================================
   Utility
   ============================================================ */
.grid { display: grid; gap: 22px; }
.g-2 { grid-template-columns: repeat(2, 1fr); }
.g-3 { grid-template-columns: repeat(3, 1fr); }
.g-4 { grid-template-columns: repeat(4, 1fr); }
.center { text-align: center; }
.mt-0 { margin-top: 0; } .mt-1 { margin-top: 12px; } .mt-2 { margin-top: 24px; } .mt-3 { margin-top: 40px; }
.muted { color: var(--text-mute); }
.hidden { display: none !important; }
.reveal { opacity: 0; transform: translateY(22px); transition: opacity .6s ease, transform .6s ease; }
.reveal.in { opacity: 1; transform: none; }

/* ============================================================
   Responsive
   ============================================================ */
@media (max-width: 920px) {
  .g-4 { grid-template-columns: repeat(2, 1fr); }
  .g-3 { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 760px) {
  .section { padding: 60px 0; }
  .nav-links {
    position: fixed; top: 70px; left: 0; right: 0;
    flex-direction: column; align-items: stretch;
    background: var(--bg-2); border-bottom: 1px solid var(--line);
    padding: 14px 20px; gap: 4px;
    transform: translateY(-130%); transition: transform .25s ease;
    max-height: calc(100vh - 70px); overflow-y: auto;
  }
  .nav-links.open { transform: translateY(0); }
  .nav-links a { padding: 13px 14px; }
  .nav-toggle { display: grid; place-items: center; }
  .g-2, .g-3, .g-4 { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 460px) {
  .footer-grid { grid-template-columns: 1fr; }
  .wrap { padding: 0 18px; }
}

/* reduced motion */
@media (prefers-reduced-motion: reduce) {
  * { animation-duration: .001s !important; transition-duration: .001s !important; }
  html { scroll-behavior: auto; }
}