/* ============ BioVision Lab · styles ============ */
:root{
  --bg:#050a12;
  --bg2:#0a1322;
  --card:rgba(255,255,255,.045);
  --line:rgba(45,212,191,.16);
  --teal:#2dd4bf;
  --green:#34d399;
  --blue:#60a5fa;
  --red:#f87171;
  --violet:#a78bfa;
  --text:#e8f1ff;
  --muted:#8fa3bf;
  --radius:18px;
}
*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  background:var(--bg);
  color:var(--text);
  font-family:'Inter',system-ui,-apple-system,'Segoe UI',sans-serif;
  overflow-x:hidden;
  line-height:1.6;
}
body::before{
  content:"";position:fixed;inset:0;z-index:-1;
  background:
    radial-gradient(900px 500px at 15% 8%, rgba(45,212,191,.07), transparent 60%),
    radial-gradient(800px 500px at 85% 30%, rgba(167,139,250,.06), transparent 60%),
    radial-gradient(700px 600px at 50% 90%, rgba(52,211,153,.05), transparent 60%),
    var(--bg);
}
.mono{font-family:'JetBrains Mono',monospace}
.muted{color:var(--muted)}
.grad{background:linear-gradient(92deg,var(--teal),var(--green) 60%,var(--blue));-webkit-background-clip:text;background-clip:text;color:transparent}

/* ---------- nav ---------- */
.nav{
  position:fixed;top:0;left:0;right:0;z-index:100;
  display:flex;align-items:center;justify-content:space-between;
  padding:14px 28px;
  background:rgba(5,10,18,.72);backdrop-filter:blur(14px);-webkit-backdrop-filter:blur(14px);
  border-bottom:1px solid var(--line);
}
.brand{font-weight:800;font-size:1.15rem;color:var(--text);text-decoration:none;display:flex;align-items:center;gap:9px}
.brand-accent{color:var(--teal)}
.brand-dot{width:11px;height:11px;border-radius:50%;background:var(--teal);box-shadow:0 0 12px var(--teal);animation:pulseDot 2.4s infinite}
@keyframes pulseDot{0%,100%{transform:scale(1);opacity:1}50%{transform:scale(.72);opacity:.6}}
.nav-links{display:flex;gap:6px}
.nav-link{color:var(--muted);text-decoration:none;font-size:.9rem;font-weight:500;padding:8px 14px;border-radius:10px;transition:.2s}
.nav-link:hover{color:var(--text);background:rgba(45,212,191,.08)}
.nav-link.active{color:var(--teal);background:rgba(45,212,191,.1)}
.nav-toggle{display:none;background:none;border:1px solid var(--line);color:var(--text);font-size:1.2rem;border-radius:10px;padding:6px 12px;cursor:pointer}

/* ---------- hero ---------- */
.hero{position:relative;min-height:100svh;display:flex;align-items:center;justify-content:center;text-align:center;overflow:hidden;padding:120px 20px 80px}
#heroCanvas{position:absolute;inset:0;width:100%;height:100%}
.hero-inner{position:relative;z-index:2;max-width:820px}
.hero-badge{display:inline-block;font-size:.75rem;letter-spacing:.18em;font-weight:600;color:var(--teal);
  border:1px solid var(--line);border-radius:999px;padding:8px 18px;margin-bottom:26px;background:rgba(45,212,191,.06)}
.hero h1{font-size:clamp(3rem,8vw,5.6rem);font-weight:800;line-height:1.04;letter-spacing:-.02em;margin-bottom:22px}
.hero-sub{font-size:clamp(1rem,2.4vw,1.25rem);color:var(--muted);max-width:620px;margin:0 auto 36px}
.hero-sub em{color:var(--text);font-style:normal;font-weight:600}
.hero-ctas{display:flex;gap:14px;justify-content:center;flex-wrap:wrap;margin-bottom:56px}
.hero-stats{display:flex;gap:44px;justify-content:center;flex-wrap:wrap}
.stat{display:flex;flex-direction:column}
.stat-num{font-size:2rem;font-weight:800;color:var(--teal)}
.stat-lbl{font-size:.8rem;color:var(--muted);letter-spacing:.06em;text-transform:uppercase}
.scroll-hint{position:absolute;bottom:22px;left:50%;transform:translateX(-50%);color:var(--muted);font-size:.8rem;letter-spacing:.2em;animation:bob 2s infinite}
@keyframes bob{0%,100%{transform:translate(-50%,0)}50%{transform:translate(-50%,8px)}}

/* ---------- buttons ---------- */
.btn{display:inline-block;padding:14px 30px;border-radius:14px;font-weight:600;font-size:1rem;cursor:pointer;
  text-decoration:none;border:1px solid transparent;transition:transform .15s,box-shadow .2s,background .2s;font-family:inherit}
.btn-primary{background:linear-gradient(92deg,#14b8a6,#22c55e);color:#04120e;box-shadow:0 8px 28px rgba(45,212,191,.28)}
.btn-primary:hover{transform:translateY(-2px);box-shadow:0 12px 34px rgba(45,212,191,.4)}
.btn-ghost{background:rgba(255,255,255,.05);color:var(--text);border-color:var(--line)}
.btn-ghost:hover{background:rgba(255,255,255,.1);transform:translateY(-2px)}
.btn-small{padding:10px 18px;font-size:.9rem;border-radius:11px}
.btn-ghost.btn-small,button.btn-small{background:rgba(255,255,255,.05);color:var(--text);border:1px solid var(--line)}
button.btn-small:hover{background:rgba(255,255,255,.12)}

/* ---------- sections ---------- */
.section{max-width:1180px;margin:0 auto;padding:90px 24px 30px}
.section-head{text-align:center;margin-bottom:36px}
.kicker{font-size:.75rem;letter-spacing:.22em;font-weight:700;color:var(--teal);margin-bottom:12px}
.section-head h2{font-size:clamp(2rem,5vw,3rem);font-weight:800;letter-spacing:-.01em;margin-bottom:10px}
.section-sub{color:var(--muted);max-width:640px;margin:0 auto;font-size:1.05rem}
.glass{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);
  backdrop-filter:blur(16px);-webkit-backdrop-filter:blur(16px);
  box-shadow:0 20px 60px rgba(0,0,0,.35), inset 0 1px 0 rgba(255,255,255,.06)}
.panel{padding:30px}

/* ---------- DNA module ---------- */
.dna-layout{display:grid;grid-template-columns:1.35fr 1fr;gap:28px;align-items:stretch}
.dna-canvas-wrap{position:relative;min-height:420px;border-radius:14px;overflow:hidden;background:radial-gradient(ellipse at 50% 40%,#0b1a2c,#050b14);border:1px solid rgba(45,212,191,.1)}
#dnaCanvas{width:100%;height:100%;display:block;min-height:420px}
.dna-side{display:flex;flex-direction:column;gap:14px}
.step-count{font-family:'JetBrains Mono',monospace;font-size:.75rem;letter-spacing:.2em;color:var(--teal)}
.dna-side h3{font-size:1.6rem;font-weight:700}
.explainer{color:#c3d4ec;font-size:.98rem;min-height:132px}
.enzyme-row{display:flex;flex-wrap:wrap;gap:8px}
.enzyme-chip{font-size:.78rem;font-weight:600;padding:6px 13px;border-radius:999px;border:1px solid var(--line);
  color:var(--muted);display:flex;align-items:center;gap:7px;transition:.25s;background:rgba(255,255,255,.03)}
.enzyme-chip i{width:9px;height:9px;border-radius:50%;background:currentColor;display:inline-block}
.enzyme-chip.active{color:#04120e;border-color:transparent;box-shadow:0 4px 16px rgba(0,0,0,.4)}
.dna-controls{display:flex;gap:10px;flex-wrap:wrap}
.step-pills{display:flex;gap:8px;flex-wrap:wrap;margin-top:4px}
.pill{flex:1;min-width:80px;padding:9px 6px;font-size:.72rem;font-weight:600;text-align:center;border-radius:10px;cursor:pointer;
  border:1px solid var(--line);color:var(--muted);background:rgba(255,255,255,.03);transition:.2s;font-family:inherit}
.pill:hover{color:var(--text)}
.pill.active{color:#04120e;background:linear-gradient(92deg,var(--teal),var(--green));border-color:transparent}

/* ---------- Heart module ---------- */
.heart-layout{display:grid;grid-template-columns:1fr 1fr;gap:28px;align-items:start}
.heart-svg-wrap{background:radial-gradient(ellipse at 50% 40%,#14090f,#05070d);border-radius:14px;border:1px solid rgba(248,113,113,.12);padding:10px}
#heartSvg{width:100%;height:auto;display:block;max-height:560px}
#heartBeat{transform-origin:center;transform-box:fill-box;animation:heartbeat 0.833s ease-in-out infinite}
@keyframes heartbeat{0%,100%{transform:scale(1)}14%{transform:scale(1.055)}28%{transform:scale(1)}42%{transform:scale(1.035)}56%{transform:scale(1)}}
.heart-side{display:flex;flex-direction:column;gap:20px}
.control-block{background:rgba(255,255,255,.03);border:1px solid var(--line);border-radius:14px;padding:20px}
.control-title{font-size:.72rem;letter-spacing:.2em;font-weight:700;color:var(--teal);margin-bottom:14px}
.toggle-row{display:flex;gap:12px;flex-wrap:wrap}
.toggle{display:flex;align-items:center;gap:10px;background:rgba(255,255,255,.04);border:1px solid var(--line);
  color:var(--muted);border-radius:999px;padding:9px 18px 9px 12px;font-size:.88rem;font-weight:600;cursor:pointer;transition:.25s;font-family:inherit}
.toggle .knob{width:34px;height:19px;border-radius:999px;background:#1c2b3f;position:relative;transition:.25s;flex-shrink:0}
.toggle .knob::after{content:"";position:absolute;top:2.5px;left:3px;width:14px;height:14px;border-radius:50%;background:#8fa3bf;transition:.25s}
.toggle.on{color:var(--text);border-color:rgba(45,212,191,.4)}
.toggle.on .knob{background:rgba(45,212,191,.35)}
.toggle.on .knob::after{left:17px;background:var(--teal);box-shadow:0 0 8px var(--teal)}
.bpm-label{display:block;margin:18px 0 8px;font-size:.85rem;font-weight:600;color:var(--text)}
.bpm-state{color:var(--muted);font-weight:400}
#bpmSlider{width:100%;accent-color:var(--teal);cursor:pointer;height:28px}
.bpm-ticks{display:flex;justify-content:space-between;font-size:.72rem;color:var(--muted);font-family:'JetBrains Mono',monospace}
.circuit{list-style:none;display:flex;flex-direction:column;gap:11px;font-size:.94rem;color:#c3d4ec}
.circuit .dot{width:10px;height:10px;border-radius:50%;display:inline-block;margin-right:10px}
.dot.blue{background:var(--blue);box-shadow:0 0 8px var(--blue)}
.dot.red{background:var(--red);box-shadow:0 0 8px var(--red)}
.circuit em{color:var(--muted);font-size:.82rem}

/* ---------- Cell module ---------- */
.cell-layout{display:grid;grid-template-columns:1.5fr 1fr;gap:28px;align-items:stretch}
.cell-svg-wrap{background:radial-gradient(ellipse at 50% 45%,#0a1826,#050b14);border-radius:14px;border:1px solid rgba(45,212,191,.1);padding:8px}
#cellSvg{width:100%;height:auto;display:block}
.org{cursor:pointer;outline:none}
.org .org-shape{transition:.25s}
.org:hover .org-shape,.org:focus .org-shape{filter:url(#orgGlow) brightness(1.35)}
.org.selected .org-shape{filter:url(#orgGlow) brightness(1.5)}
.cell-card{background:rgba(255,255,255,.03);border:1px solid var(--line);border-radius:14px;padding:26px;position:relative;min-height:340px}
.cell-card-empty{text-align:center;color:var(--muted);padding-top:70px}
.cell-card-icon{font-size:3rem;margin-bottom:16px}
.cell-card-body .kicker{margin-bottom:6px}
.cell-card-body h3{font-size:1.7rem;margin-bottom:12px}
.cell-card-body p{color:#c3d4ec;font-size:.97rem}
.fact-box{margin-top:18px;background:rgba(45,212,191,.07);border:1px solid rgba(45,212,191,.25);border-radius:12px;padding:14px 16px}
.fact-tag{font-size:.68rem;font-weight:800;letter-spacing:.18em;color:var(--teal)}
.fact-box p{margin-top:6px;font-size:.9rem}
.card-close{position:absolute;top:14px;right:14px;background:none;border:1px solid var(--line);color:var(--muted);
  width:30px;height:30px;border-radius:9px;cursor:pointer;font-size:.85rem}
.card-close:hover{color:var(--text);background:rgba(255,255,255,.08)}

/* ---------- Quiz ---------- */
.quiz-panel{max-width:760px;margin:0 auto;text-align:center;padding:44px 34px}
.quiz-start-icon{font-size:3.4rem;margin-bottom:16px}
.quiz-panel h3{font-size:1.6rem;margin-bottom:10px}
#btnStartQuiz,#btnRetry{margin-top:22px}
.quiz-top{display:flex;justify-content:space-between;align-items:center;margin-bottom:12px;font-size:.85rem}
.quiz-topic{color:var(--teal);font-weight:600;font-size:.8rem;letter-spacing:.08em;text-transform:uppercase}
.progress{height:8px;background:rgba(255,255,255,.07);border-radius:99px;overflow:hidden;margin-bottom:26px}
.progress-fill{height:100%;width:0;background:linear-gradient(90deg,var(--teal),var(--green));border-radius:99px;transition:width .4s ease}
#quizQ{font-size:1.25rem;margin-bottom:22px;text-align:left}
.quiz-opts{display:flex;flex-direction:column;gap:10px;text-align:left}
.opt{padding:14px 18px;border-radius:12px;border:1px solid var(--line);background:rgba(255,255,255,.03);
  color:var(--text);cursor:pointer;font-size:.96rem;transition:.18s;font-family:inherit;text-align:left;width:100%}
.opt:hover:not(:disabled){border-color:var(--teal);background:rgba(45,212,191,.07);transform:translateX(4px)}
.opt:disabled{cursor:default;opacity:.85}
.opt.correct{border-color:var(--green);background:rgba(52,211,153,.14);box-shadow:0 0 18px rgba(52,211,153,.18)}
.opt.wrong{border-color:var(--red);background:rgba(248,113,113,.12)}
.opt .key{display:inline-block;width:26px;height:26px;border-radius:8px;background:rgba(255,255,255,.08);
  text-align:center;line-height:26px;font-size:.78rem;font-weight:700;margin-right:12px;font-family:'JetBrains Mono',monospace}
.quiz-feedback{margin:18px 0;padding:14px 18px;border-radius:12px;font-size:.93rem;text-align:left}
.quiz-feedback.good{background:rgba(52,211,153,.1);border:1px solid rgba(52,211,153,.35);color:#bdf5d6}
.quiz-feedback.bad{background:rgba(248,113,113,.1);border:1px solid rgba(248,113,113,.35);color:#ffd3d3}
#btnNextQ{margin-top:6px}
.verdict{color:var(--muted);font-size:1.05rem;max-width:480px;margin:8px auto 0}
#quizScore{font-size:2.6rem;font-weight:800}

/* ---------- footer ---------- */
.footer{margin-top:90px;border-top:1px solid var(--line);padding:44px 24px 34px;text-align:center;background:rgba(255,255,255,.015)}
.foot-inner{max-width:640px;margin:0 auto;display:flex;flex-direction:column;gap:12px;align-items:center}
.foot-brand{font-weight:800;font-size:1.2rem;display:flex;align-items:center;gap:9px}
.footer p{color:var(--muted);font-size:.95rem}
.footer b{color:var(--text)}
.foot-links{display:flex;gap:18px}
.foot-links a{color:var(--teal);text-decoration:none;font-weight:600;font-size:.95rem}
.foot-links a:hover{text-decoration:underline}
.foot-fine{font-size:.8rem!important}

/* ---------- responsive ---------- */
@media(max-width:960px){
  .dna-layout,.heart-layout,.cell-layout{grid-template-columns:1fr}
  .explainer{min-height:0}
  #dnaCanvas{min-height:360px}
  .cell-card{min-height:0}
  .cell-card-empty{padding-top:20px}
}
@media(max-width:720px){
  .nav-links{position:fixed;top:62px;left:0;right:0;flex-direction:column;background:rgba(5,10,18,.97);
    border-bottom:1px solid var(--line);padding:12px 20px 20px;display:none}
  .nav-links.open{display:flex}
  .nav-toggle{display:block}
  .panel{padding:20px}
  .section{padding:70px 16px 20px}
  .hero-ctas .btn{width:100%;text-align:center}
  .dna-controls .btn{flex:1;text-align:center}
}
@media(prefers-reduced-motion:reduce){
  *,*::before,*::after{animation-duration:.01ms!important;transition-duration:.01ms!important}
}