/* ==========================================================================
   Pulsana — design tokens
   Palette lifted directly from the PulseWatch AI app screens so the site
   and the app feel like one product: sage green + warm paper + a single
   coral heartbeat accent.
   ========================================================================== */
:root{
  --paper:      #F5F1E6;
  --paper-2:    #EFE9DA;
  --card:       #FFFFFF;
  --ink:        #24281F;
  --ink-soft:   #5B6152;
  --line:       #E1DAC7;
  --sage:       #6E9A5E;
  --sage-dark:  #547746;
  --sage-tint:  #E4EEDE;
  --coral:      #D96C7C;
  --coral-tint: #F6DEE2;
  --gold:       #C79A3D;

  --font-display: "Fraunces", "Noto Serif SC", serif;
  --font-body:    "IBM Plex Sans", "Noto Sans SC", "Noto Sans", sans-serif;
  --font-mono:    "IBM Plex Mono", "Noto Sans SC", monospace;

  --radius-s: 8px;
  --radius-m: 16px;
  --radius-l: 28px;
  --shadow: 0 12px 30px -14px rgba(36,40,31,0.22);
  --maxw: 1080px;
}

*,*::before,*::after{ box-sizing:border-box; }
html{ scroll-behavior:smooth; }
body{
  margin:0;
  background:var(--paper);
  color:var(--ink);
  font-family:var(--font-body);
  font-size:18px;
  line-height:1.6;
  -webkit-font-smoothing:antialiased;
}
img{ max-width:100%; display:block; }
a{ color:inherit; }
.wrap{ max-width:var(--maxw); margin:0 auto; padding:0 24px; }

h1,h2,h3{
  font-family:var(--font-display);
  font-weight:600;
  line-height:1.15;
  margin:0 0 .5em;
  letter-spacing:-0.01em;
}
h1{ font-size:clamp(2.3rem, 4.9vw, 3.7rem); }
h2{ font-size:clamp(1.65rem, 3.2vw, 2.3rem); }
h3{ font-size:1.3rem; }
p{ margin:0 0 1em; color:var(--ink-soft); }
.eyebrow{
  font-family:var(--font-mono);
  font-size:.8rem;
  letter-spacing:.14em;
  text-transform:uppercase;
  color:var(--sage-dark);
  display:inline-flex;
  align-items:center;
  gap:8px;
  margin-bottom:14px;
}
.eyebrow::before{
  content:"";
  width:18px; height:1px;
  background:var(--sage-dark);
}

/* ---- header / nav ---- */
.site-header{
  position:sticky; top:0; z-index:50;
  background:var(--paper);
  border-bottom:1px solid var(--line);
}
.nav{
  display:flex; align-items:center; justify-content:space-between;
  padding:16px 24px;
  max-width:var(--maxw); margin:0 auto;
}
.brand{
  display:flex; align-items:center; gap:10px;
  font-family:var(--font-display); font-weight:600; font-size:1.25rem;
  text-decoration:none; color:var(--ink);
}
.brand-mark{ width:34px; height:34px; flex:none; }
.nav-links{
  display:flex; align-items:center; gap:28px;
  list-style:none; margin:0; padding:0;
}
.nav-links a{
  text-decoration:none; font-size:1.02rem; color:var(--ink-soft);
  padding:6px 2px; border-bottom:2px solid transparent;
  transition:color .15s, border-color .15s;
}
.nav-links a:hover, .nav-links a.active{
  color:var(--ink); border-color:var(--sage);
}
.nav-right{ display:flex; align-items:center; gap:18px; }
.lang-switch{
  display:flex; gap:2px; background:var(--paper-2);
  border-radius:999px; padding:3px; font-family:var(--font-mono); font-size:.8rem;
}
.lang-switch button{
  border:0; background:transparent; padding:6px 10px; border-radius:999px;
  cursor:pointer; color:var(--ink-soft); font-family:inherit; font-size:inherit;
  letter-spacing:.03em;
}
.lang-switch button.active{ background:var(--card); color:var(--ink); box-shadow:0 1px 3px rgba(0,0,0,.12); }
.nav-toggle{ display:none; }

/* ---- buttons ---- */
.btn{
  display:inline-flex; align-items:center; justify-content:center; gap:8px;
  font-family:var(--font-body); font-weight:600; font-size:1.04rem;
  padding:14px 26px; border-radius:999px; border:1px solid transparent;
  text-decoration:none; cursor:pointer; transition:transform .15s ease, box-shadow .15s ease, background .15s ease;
}
.btn:active{ transform:translateY(1px); }
.btn-primary{ background:var(--sage); color:#fff; box-shadow:0 10px 24px -10px rgba(84,119,70,.55); }
.btn-primary:hover{ background:var(--sage-dark); }
.btn-ghost{ background:transparent; border-color:var(--line); color:var(--ink); }
.btn-ghost:hover{ border-color:var(--sage); color:var(--sage-dark); }
.btn-block{ width:100%; }
.btn[disabled]{ opacity:.5; cursor:not-allowed; }

/* ---- hero ---- */
.hero{ padding:72px 0 56px; position:relative; overflow:hidden; }
.hero-grid{ display:grid; grid-template-columns:1.1fr .9fr; gap:56px; align-items:center; }
.hero p.lead{ font-size:1.22rem; max-width:46ch; }
.hero-cta{ display:flex; gap:14px; flex-wrap:wrap; margin-top:28px; }
.pulse-line{ width:100%; height:auto; }
.pulse-path{
  fill:none; stroke:var(--coral); stroke-width:2.4;
  stroke-linecap:round; stroke-linejoin:round;
  stroke-dasharray:1400; stroke-dashoffset:1400;
  animation:draw 3.2s ease-out forwards, pulse-glow 2.6s ease-in-out 3.2s infinite;
}
@keyframes draw{ to{ stroke-dashoffset:0; } }
@keyframes pulse-glow{
  0%,100%{ opacity:1; } 50%{ opacity:.45; }
}
@media (prefers-reduced-motion: reduce){
  .pulse-path{ animation:none; stroke-dashoffset:0; }
}

/* ---- component / feature cards ---- */
.grid-3{ display:grid; grid-template-columns:repeat(3,1fr); gap:20px; }
.grid-2{ display:grid; grid-template-columns:repeat(2,1fr); gap:20px; }
.card{
  background:var(--card); border:1px solid var(--line); border-radius:var(--radius-m);
  padding:26px; box-shadow:var(--shadow);
}
.card .num{
  font-family:var(--font-mono); font-size:.75rem; color:var(--sage-dark);
  background:var(--sage-tint); display:inline-block; padding:3px 9px; border-radius:999px;
  margin-bottom:14px;
}
.card h3{ margin-bottom:8px; }
.card p{ margin-bottom:0; font-size:1.03rem; }
.icon-badge{
  width:44px; height:44px; border-radius:12px;
  display:flex; align-items:center; justify-content:center;
  background:var(--sage-tint); color:var(--sage-dark); margin-bottom:16px;
}
.icon-badge.coral{ background:var(--coral-tint); color:var(--coral); }

section{ padding:56px 0; }
.section-alt{ background:var(--card); border-top:1px solid var(--line); border-bottom:1px solid var(--line); }
.section-head{ max-width:640px; margin-bottom:36px; }
.section-head.center{ margin-left:auto; margin-right:auto; text-align:center; }

/* ---- callouts ---- */
.callout{
  border-radius:var(--radius-m); padding:20px 24px; display:flex; gap:14px; align-items:flex-start;
  border:1px solid var(--line);
}
.callout-48{
  background:var(--coral-tint); border-color:#ecc2ca;
}
.callout-48 .callout-icon{ color:var(--coral); flex:none; margin-top:2px; }
.callout-note{ background:var(--sage-tint); border-color:#cfe2c6; }
.callout h4{ margin:0 0 4px; font-family:var(--font-body); font-weight:700; font-size:1.03rem; }
.callout p{ margin:0; font-size:.98rem; }

/* ---- steps ---- */
.step{
  display:grid; grid-template-columns:56px 1fr; gap:20px;
  padding:32px 0; border-bottom:1px solid var(--line);
}
.step:last-child{ border-bottom:0; }
.step-index{
  width:44px; height:44px; border-radius:50%; background:var(--ink);
  color:var(--paper); font-family:var(--font-mono); font-size:1.03rem;
  display:flex; align-items:center; justify-content:center;
}
.step h3{ margin-bottom:6px; }
.step-body p{ font-size:1.05rem; }
.photo-row{ display:flex; gap:14px; margin-top:16px; flex-wrap:wrap; }
.photo-slot{ position:relative; width:200px; height:400px; max-width:48vw; }
.photo-slot img{
  width:100%; height:100%; object-fit:cover; border-radius:20px;
  border:1px solid var(--line); display:block; background:var(--card);
}
.photo-placeholder{
  width:200px; height:400px; max-width:48vw;
  border-radius:20px; border:1.5px dashed #C9BE9E;
  background:
    repeating-linear-gradient(135deg, #EFE9DA 0 10px, #F5F1E6 10px 20px);
  display:flex; flex-direction:column; align-items:center; justify-content:center;
  gap:8px; text-align:center; padding:14px; color:var(--ink-soft);
  font-family:var(--font-mono); font-size:.72rem;
}
.photo-placeholder svg{ width:34px; height:34px; opacity:.6; }
.photo-slot .photo-placeholder{ position:absolute; inset:0; width:100%; height:100%; max-width:none; }
.watch-card{
  background:var(--paper-2); border:1px solid var(--line); border-radius:var(--radius-m);
  padding:20px; margin-top:16px; font-size:1rem;
}
.watch-card ul{ margin:0; padding-left:1.2em; }
.watch-card li{ margin-bottom:8px; }

.video-frame{
  aspect-ratio:16/9; width:100%; border-radius:var(--radius-l);
  background:linear-gradient(135deg,#2B3126,#3C4432);
  display:flex; align-items:center; justify-content:center; position:relative;
  overflow:hidden; box-shadow:var(--shadow); margin-bottom:14px;
}
.video-frame .play-btn{
  width:74px; height:74px; border-radius:50%; background:rgba(255,255,255,.14);
  border:1.5px solid rgba(255,255,255,.5); display:flex; align-items:center; justify-content:center;
  cursor:default;
}
.video-frame .play-btn svg{ width:26px; height:26px; fill:#fff; margin-left:4px; }
.video-frame .caption{
  position:absolute; bottom:16px; left:16px; right:16px;
  color:#EFE9DA; font-family:var(--font-mono); font-size:.75rem; letter-spacing:.03em;
  display:flex; justify-content:space-between; opacity:.8;
}

/* ---- join / consent ---- */
.consent-box{
  background:var(--card); border:1px solid var(--line); border-radius:var(--radius-l);
  padding:32px; box-shadow:var(--shadow);
}
.consent-list{ margin:0 0 20px; padding-left:1.2em; }
.consent-list li{ margin-bottom:10px; font-size:1.03rem; color:var(--ink-soft); }
.check-row{
  display:flex; gap:12px; align-items:flex-start; padding:16px; border:1px solid var(--line);
  border-radius:var(--radius-s); background:var(--paper); margin-bottom:20px;
}
.check-row input{ margin-top:4px; width:18px; height:18px; accent-color:var(--sage); flex:none; }
.check-row label{ font-size:1rem; color:var(--ink-soft); }
.disclaimer-note{
  font-size:.86rem; color:var(--ink-soft); border-left:3px solid var(--gold); padding-left:12px; margin-top:22px;
}

.result-card{
  display:none; margin-top:28px; background:var(--paper); border:1px solid var(--line);
  border-radius:var(--radius-l); padding:32px; text-align:center;
}
.result-card.show{ display:block; animation:fade-up .5s ease both; }
@keyframes fade-up{ from{ opacity:0; transform:translateY(10px);} to{opacity:1; transform:translateY(0);} }
.code-display{
  font-family:var(--font-mono); font-size:1.9rem; letter-spacing:.35em;
  background:var(--sage-tint); color:var(--sage-dark); border-radius:var(--radius-s);
  padding:18px 10px; margin:16px 0; word-break:break-all;
}
.research-id{ font-family:var(--font-mono); font-size:.86rem; color:var(--ink-soft); }

/* ---- FAQ ---- */
.faq-item{ border-bottom:1px solid var(--line); }
.faq-item:first-child{ border-top:1px solid var(--line); }
.faq-q{
  width:100%; text-align:left; background:none; border:0; cursor:pointer;
  padding:20px 4px; display:flex; justify-content:space-between; align-items:center; gap:16px;
  font-family:var(--font-body); font-weight:600; font-size:1rem; color:var(--ink);
}
.faq-q .plus{ font-family:var(--font-mono); font-size:1.2rem; color:var(--sage-dark); transition:transform .2s; flex:none; }
.faq-item.open .faq-q .plus{ transform:rotate(45deg); }
.faq-a{ max-height:0; overflow:hidden; transition:max-height .28s ease; }
.faq-item.open .faq-a{ max-height:400px; }
.faq-a p{ padding:0 4px 20px; font-size:1.03rem; }

/* ---- contact ---- */
.contact-grid{ display:grid; grid-template-columns:repeat(2,1fr); gap:20px; }
.contact-card{
  background:var(--card); border:1px solid var(--line); border-radius:var(--radius-m); padding:24px;
}
.contact-card .label{ font-family:var(--font-mono); font-size:.8rem; text-transform:uppercase; letter-spacing:.08em; color:var(--sage-dark); }
.contact-card .value{ font-size:1.14rem; font-weight:600; margin:6px 0 0; word-break:break-word; }
.qr-row{ display:flex; gap:16px; margin-top:10px; }
.qr-placeholder{
  width:145px; height:145px; border-radius:var(--radius-s); border:1.5px dashed #C9BE9E;
  background:repeating-linear-gradient(45deg, #EFE9DA 0 8px, #F5F1E6 8px 16px);
  display:flex; align-items:center; justify-content:center; text-align:center;
  font-family:var(--font-mono); font-size:.72rem; color:var(--ink-soft); padding:8px;
}
.qr-img{
  width:145px; height:145px; object-fit:cover; border-radius:var(--radius-s);
  border:1px solid var(--line); background:var(--paper);
}
.contact-row{ margin-top:14px; }
.contact-row:first-of-type{ margin-top:4px; }
.simple-form{ display:grid; gap:14px; }
.simple-form input, .simple-form textarea{
  font-family:var(--font-body); font-size:1.03rem; padding:13px 14px; border-radius:var(--radius-s);
  border:1px solid var(--line); background:var(--paper); color:var(--ink);
}
.simple-form textarea{ resize:vertical; min-height:110px; }
.form-note{ font-size:.86rem; }

/* ---- footer ---- */
footer{ border-top:1px solid var(--line); padding:40px 0; }
.footer-grid{ display:flex; justify-content:space-between; flex-wrap:wrap; gap:24px; align-items:center; }
.footer-links{ display:flex; gap:22px; list-style:none; padding:0; margin:0; flex-wrap:wrap; }
.footer-links a{ text-decoration:none; color:var(--ink-soft); font-size:.88rem; }
.footer-links a:hover{ color:var(--sage-dark); }
.footer-fine{ font-size:.86rem; color:var(--ink-soft); }

/* ---- language-specific type tuning ---- */
html[lang="zh"] h1, html[lang="zh"] h2, html[lang="zh"] h3{ font-family:"Noto Serif SC", var(--font-display); letter-spacing:0; }
html[lang="zh"] body, html[lang="zh"] .eyebrow, html[lang="zh"] .code-display{ font-family:"Noto Sans SC", var(--font-body); }

/* ---- responsive ---- */
@media (max-width:860px){
  .hero-grid{ grid-template-columns:1fr; gap:36px; }
  .grid-3{ grid-template-columns:1fr; }
  .grid-2, .contact-grid{ grid-template-columns:1fr; }
  .nav-links{
    position:absolute; top:100%; left:0; right:0; background:var(--paper); border-bottom:1px solid var(--line);
    flex-direction:column; align-items:flex-start; padding:18px 24px; gap:6px;
    /* translateY(-100%) clears the panel's own height from its top:100% start
       point (i.e. fully above the header's bottom edge); the extra -100px
       then clears the header's own height too, however tall it renders — a
       fixed % here broke once the panel got taller than assumed (see commit
       history) since "-120%" is only ever 120% of the panel's OWN height,
       not the header's, so it fell short of clearing both. */
    transform:translateY(calc(-100% - 100px)); transition:transform .2s ease; box-shadow:var(--shadow);
  }
  .nav-links.open{ transform:translateY(0); }
  .nav-links a{ width:100%; padding:10px 0; }
  .nav-toggle{
    display:flex; align-items:center; justify-content:center; width:38px; height:38px;
    border:1px solid var(--line); border-radius:10px; background:var(--card); cursor:pointer;
  }
  .nav-toggle svg{ width:18px; height:18px; }
  .nav-right .btn-primary{ display:none; }
}
@media (max-width:520px){
  .photo-placeholder, .photo-slot{ width:165px; height:330px; }
}