/* Runtime (runtime.proverify.ai) — Proverify.ai design system, Runtime green as primary accent.
   Restyled from milli.run: same content architecture and interactive trace demo,
   minimalist black/white/gray base instead of off-white/lime, rounded components,
   shared Proverify.ai sans instead of JetBrains Mono. */

:root{
  --bg:#fff;
  --alt:#f5f5f7;
  --line:#dedede;
  --ink:#0a0a0a;
  --muted:#63636b;
  --radius:22px;
  --shadow:0 24px 60px rgba(0,0,0,.08);

  --accent:#2E6B4F;        /* Runtime signal green */
  --accent-mid:#75A692;
  --accent-tint:#EDF4F0;
  --accent-line:#C6DBD0;
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{background:var(--bg);color:var(--ink);font-family:-apple-system,BlinkMacSystemFont,"SF Pro Display","Inter",Segoe UI,sans-serif;line-height:1.6;-webkit-font-smoothing:antialiased}
a{color:inherit}
.sub a{text-decoration:underline;text-decoration-thickness:1px;text-underline-offset:3px}
button,input{font:inherit;color:inherit;background:none;border:0;cursor:pointer}

nav{position:fixed;top:0;left:0;right:0;z-index:20;padding:20px 60px;display:flex;align-items:center;justify-content:space-between;background:rgba(255,255,255,.9);backdrop-filter:blur(20px);border-bottom:1px solid var(--line)}
.product-badge{display:inline-flex;align-items:center;overflow:hidden;border:1px solid var(--accent-line);border-radius:999px;background:#fff;font-weight:700;line-height:1;text-decoration:none;white-space:nowrap;box-shadow:0 4px 14px rgba(0,0,0,.04)}
.product-badge .brand-name{padding:9px 12px;color:var(--ink);font-size:15px;letter-spacing:-.03em}
.product-badge .product-name{align-self:stretch;display:flex;align-items:center;padding:9px 12px;background:var(--accent-tint);border-left:1px solid var(--accent-line);color:var(--accent);font-size:12px;letter-spacing:.04em}
.nav-links{display:flex;gap:26px;list-style:none}
.nav-links a{font-size:14px;font-weight:500;text-decoration:none;color:var(--muted)}
.nav-links a:hover{color:var(--ink)}
.btn{display:inline-flex;align-items:center;justify-content:center;padding:11px 20px;border-radius:999px;text-decoration:none;font-size:13px;font-weight:700;border:1px solid var(--ink);background:var(--ink);color:#fff}
.btn.secondary{background:transparent;color:var(--ink);border-color:var(--line)}
.btn.session-trigger{background:var(--accent);color:#fff;border-color:var(--accent)}
.btn.session-trigger:hover{filter:brightness(.95)}
.nav-actions,.cta-actions{display:flex;align-items:center;gap:12px}

section{padding:80px 80px;border-bottom:1px solid var(--line)}
section.alt{background:var(--alt)}
.hero{min-height:78vh;padding-top:160px}
.label{font-size:11px;font-weight:700;letter-spacing:.1em;text-transform:uppercase;color:var(--accent);margin-bottom:18px}
h1{font-size:clamp(40px,6vw,72px);font-weight:700;letter-spacing:-.045em;line-height:1.05;max-width:1100px;margin-bottom:26px}
h1 em{font-style:normal;color:var(--muted)}
h2{font-size:clamp(30px,3.7vw,46px);font-weight:700;letter-spacing:-.03em;line-height:1.1;max-width:960px;margin-bottom:22px}
h3{font-size:18px;font-weight:650;letter-spacing:-.01em;margin-bottom:10px}
p{color:#4b4b4b;font-size:14px;line-height:1.65}
.sub,.intro{font-size:18px;color:#4b4b4b;max-width:800px;line-height:1.65;margin-bottom:40px}
.intro{font-size:16px}
.cta-row{display:flex;gap:12px;align-items:center;flex-wrap:wrap;margin-bottom:50px}

.metric-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:36px;border-top:1px solid var(--line);padding-top:36px;max-width:1120px}
.metric{border-left:1px solid var(--line);padding-left:18px}
.metric:first-child{border-left:none;padding-left:0}
.metric-value{font-size:38px;font-weight:700;letter-spacing:-.02em;line-height:1}
.metric-value .unit{font-size:18px;color:var(--muted);font-weight:400;margin-left:2px}
.metric-label{font-size:12px;color:var(--muted);line-height:1.45;margin-top:8px}

.grid-2{display:grid;grid-template-columns:1fr 1fr;gap:28px;margin-top:26px}
.grid-3{display:grid;grid-template-columns:repeat(3,1fr);gap:22px;margin-top:26px}
.card{background:var(--bg);border:1px solid var(--line);border-radius:var(--radius);padding:24px}
.alt .card{background:var(--bg)}
.card-label{font-size:11px;font-weight:700;letter-spacing:.08em;text-transform:uppercase;color:var(--accent);margin-bottom:12px}
.card strong{color:var(--ink)}

.guarantees{display:grid;grid-template-columns:repeat(6,1fr);gap:16px;margin-top:26px}
.guarantee{border-top:2px solid var(--accent);padding-top:14px}
.guarantee strong{display:block;font-size:13px;margin-bottom:8px}
.guarantee span{display:block;font-size:12px;color:var(--muted);line-height:1.5}

.note{max-width:1040px;margin-top:22px;padding:16px 18px;border:1px solid var(--line);border-left:3px solid var(--accent);border-radius:14px;background:var(--alt);color:#4b4b4b;font-size:13px;line-height:1.6}
.alt .note{background:var(--bg)}
.note strong{color:var(--ink)}

.proof-points{display:grid;grid-template-columns:1fr 1fr;gap:26px;margin-top:26px}
.phase-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:26px;margin-top:26px}
.team-note{margin-top:26px;max-width:960px;color:#4b4b4b;font-size:14px;line-height:1.7}
.team-note strong{color:var(--ink)}
.final-cta{margin-top:42px;padding-top:30px;border-top:1px solid var(--line);display:flex;align-items:center;justify-content:space-between;gap:30px;flex-wrap:wrap}
.final-cta h3{font-size:23px;margin:0}

footer{padding:30px 80px;background:var(--alt);display:flex;justify-content:space-between;gap:20px;flex-wrap:wrap;font-size:12px;color:var(--muted)}

.reveal{opacity:0;transform:translateY(10px);transition:opacity .5s ease,transform .5s ease}
.reveal.visible{opacity:1;transform:translateY(0)}

/* --- interactive trace demo (session modal) --- */
.session-modal{position:fixed;inset:0;z-index:80;display:none;align-items:center;justify-content:center;padding:24px}
.session-modal.open{display:flex}
.session-backdrop{position:absolute;inset:0;background:rgba(10,10,10,.65);backdrop-filter:blur(4px)}
.session-window{position:relative;z-index:1;width:min(1120px,100%);max-height:min(88vh,920px);overflow:hidden;background:var(--bg);border-radius:26px;box-shadow:var(--shadow);display:grid;grid-template-rows:auto auto 1fr auto}
.session-head{display:flex;align-items:flex-start;justify-content:space-between;gap:24px;padding:26px 30px 20px;border-bottom:1px solid var(--line);background:var(--alt);border-radius:26px 26px 0 0}
.session-head h2{font-size:clamp(24px,3vw,36px);margin:0;max-width:none}
.session-close{width:38px;height:38px;border:1px solid var(--line);border-radius:999px;background:var(--bg);font-size:22px;line-height:1;display:flex;align-items:center;justify-content:center}
.session-close:hover{border-color:var(--ink)}
.session-toggle-wrap{padding:14px 30px;border-bottom:1px solid var(--line);display:flex;align-items:center;justify-content:space-between;gap:20px;background:var(--bg)}
.session-mode-toggle{position:relative;display:grid;grid-template-columns:1fr 1fr;width:min(440px,100%);border:1px solid var(--line);border-radius:999px;background:var(--alt);padding:3px}
.session-mode-toggle:before{content:"";position:absolute;top:3px;bottom:3px;left:3px;width:calc(50% - 3px);background:var(--ink);border-radius:999px;transition:transform .22s ease}
.session-mode-toggle[data-mode="runtime"]:before{transform:translateX(100%)}
.mode-option{position:relative;z-index:1;padding:9px 14px;font-size:11px;font-weight:700;letter-spacing:.04em;text-transform:uppercase;color:var(--muted);border-radius:999px}
.mode-option.active{color:#fff}
.session-status{font-size:11px;font-weight:700;letter-spacing:.05em;text-transform:uppercase;color:var(--muted);white-space:nowrap}
.session-status strong{color:var(--ink)}
.session-body{overflow:auto;padding:26px 30px;background:linear-gradient(180deg,var(--bg),var(--alt))}
.session-grid{display:grid;grid-template-columns:minmax(220px,.9fr) minmax(0,1.6fr);gap:20px;align-items:start}
.customer-panel,.runtime-panel{background:var(--bg);border:1px solid var(--line);border-radius:16px;overflow:hidden}
.panel-head{display:flex;align-items:center;justify-content:space-between;gap:12px;padding:13px 16px;border-bottom:1px solid var(--line);font-size:10px;font-weight:700;letter-spacing:.08em;text-transform:uppercase;color:var(--muted)}
.panel-head strong{color:var(--ink)}
.turn-list{padding:12px;display:grid;gap:10px}
.turn-chip{border:1px solid var(--line);border-radius:12px;background:var(--bg);padding:12px;text-align:left;width:100%;display:block}
.turn-chip.active{border-color:var(--accent);background:var(--accent-tint)}
.turn-chip span{display:block;font-size:10px;font-weight:700;letter-spacing:.05em;text-transform:uppercase;color:var(--muted);margin-bottom:6px}
.turn-chip.active span{color:var(--accent)}
.turn-chip p{font-size:12px;color:var(--ink);line-height:1.45;margin:0}
.runtime-stage{padding:16px;display:grid;gap:13px}
.user-utterance{border:1px solid var(--line);border-radius:12px;background:var(--alt);padding:13px 15px;font-size:14px;color:var(--ink)}
.user-utterance strong{display:block;font-size:10px;font-weight:700;letter-spacing:.08em;text-transform:uppercase;color:var(--muted);margin-bottom:6px}
.state-row{display:grid;grid-template-columns:repeat(3,1fr);gap:10px}
.state-card{border:1px solid var(--line);border-radius:12px;background:var(--bg);padding:11px}
.state-card b{display:block;font-size:10px;font-weight:700;letter-spacing:.08em;text-transform:uppercase;color:var(--muted);margin-bottom:6px}
.state-card span{display:block;font-size:13px;font-weight:700;color:var(--ink);line-height:1.4}
.slot-grid{display:grid;grid-template-columns:1fr 1fr;gap:10px}
.slot-box{border:1px solid var(--line);border-radius:12px;padding:11px;background:var(--bg)}
.slot-box b{display:block;font-size:10px;font-weight:700;letter-spacing:.08em;text-transform:uppercase;color:var(--muted);margin-bottom:8px}
.slot-tags{display:flex;flex-wrap:wrap;gap:6px}
.slot-tag{display:inline-flex;border:1px solid var(--line);border-radius:999px;padding:4px 9px;font-size:11px;font-weight:600;background:var(--alt);color:var(--ink)}
.slot-tag.missing{background:var(--bg);color:var(--muted);border-style:dashed}
.candidate-list{display:grid;gap:6px}
.candidate-row{display:grid;grid-template-columns:66px 130px minmax(0,1fr);gap:10px;align-items:center;border:1px solid var(--line);border-radius:10px;background:var(--bg);padding:8px 10px;font-size:12px;color:var(--muted)}
.candidate-row.top{border-color:var(--ink)}
.candidate-row.correct{background:var(--accent-tint);border-color:var(--accent-line)}
.candidate-score{font-size:11px;font-weight:700;color:var(--ink)}
.candidate-asin{font-size:10px;font-weight:700;color:var(--muted)}
.candidate-title{white-space:nowrap;overflow:hidden;text-overflow:ellipsis;color:var(--ink)}
.ask-card{border:1px solid var(--ink);border-radius:14px;background:var(--ink);color:#fff;padding:14px;display:grid;gap:10px}
.ask-card b{font-size:11px;font-weight:700;letter-spacing:.06em;text-transform:uppercase;color:var(--accent-mid)}
.choice-row{display:flex;flex-wrap:wrap;gap:8px}
.choice-pill{display:inline-flex;align-items:center;border:1px solid rgba(255,255,255,.3);border-radius:999px;padding:6px 10px;font-size:11px;font-weight:700;background:rgba(255,255,255,.08);color:#fff}
.flow-strip{display:grid;grid-template-columns:repeat(4,1fr);gap:2px;margin-top:2px}
.flow-node{border-top:2px solid var(--line);padding-top:8px;font-size:10px;font-weight:700;letter-spacing:.04em;text-transform:uppercase;color:var(--muted)}
.flow-node.active{border-color:var(--accent);color:var(--ink)}
.llm-response{border:1px solid var(--line);border-radius:14px;background:var(--bg);padding:16px;display:grid;gap:12px}
.llm-bubble{padding:15px;border:1px solid var(--line);border-radius:12px;background:var(--alt);color:var(--ink);font-size:14px;line-height:1.6}
.llm-bubble strong{display:block;margin-bottom:6px;color:var(--ink)}
.llm-cost-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:10px}
.llm-cost{border:1px solid var(--line);border-radius:10px;padding:10px;background:var(--bg)}
.llm-cost b{display:block;font-size:10px;font-weight:700;letter-spacing:.08em;text-transform:uppercase;color:var(--muted);margin-bottom:5px}
.llm-cost span{font-size:12px;font-weight:700;color:var(--ink)}
.latency-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:8px}
.latency-card{border:1px solid var(--line);border-radius:10px;background:var(--bg);padding:10px}
.latency-card b{display:block;font-size:9px;font-weight:700;letter-spacing:.08em;text-transform:uppercase;color:var(--muted);margin-bottom:5px}
.latency-card span{display:block;font-size:12px;font-weight:700;color:var(--ink);line-height:1.35}
.latency-note{border:1px solid var(--line);border-radius:10px;background:var(--alt);padding:10px 12px;font-size:10px;font-weight:700;letter-spacing:.03em;text-transform:uppercase;color:var(--muted)}
.latency-note strong{color:var(--ink)}
.session-controls{display:flex;align-items:center;justify-content:space-between;gap:16px;padding:16px 30px;border-top:1px solid var(--line);background:var(--bg)}
.session-stepper{font-size:11px;font-weight:700;letter-spacing:.04em;text-transform:uppercase;color:var(--muted)}
.session-control-buttons{display:flex;gap:10px}
.session-control-buttons .btn{padding:9px 14px;border-radius:999px}

@media(max-width:1024px){
  .session-grid{grid-template-columns:1fr}
  .state-row,.llm-cost-grid,.latency-grid{grid-template-columns:1fr 1fr}
  section{padding:56px 40px}
  .metric-grid{grid-template-columns:repeat(2,1fr)}
  .grid-2,.grid-3,.proof-points,.phase-grid{grid-template-columns:1fr}
  .guarantees{grid-template-columns:repeat(3,1fr)}
}
@media(max-width:760px){
  nav{padding:16px 20px;flex-wrap:wrap;gap:12px}
  .nav-links{order:3;width:100%;justify-content:center;gap:16px;border-top:1px solid var(--line);padding-top:12px}
  .nav-links a{font-size:12px}
  section{padding:44px 20px}
  .hero{min-height:auto;padding-top:140px}
  .sub,.intro{font-size:15px}
  .cta-row{flex-direction:column;align-items:stretch}
  .metric-grid,.guarantees{grid-template-columns:1fr}
  .metric{border-left:none;border-top:1px solid var(--line);padding:16px 0 0}
  .metric:first-child{border-top:none;padding-top:0}
  .final-cta{display:block}
  .final-cta .btn{margin-top:20px;width:100%}
  footer{padding:26px 20px;display:block}
  .nav-actions{order:2;margin-left:auto;gap:8px}
  .nav-actions .btn{padding:8px 12px;font-size:12px}
  .cta-actions{margin-top:18px;display:grid;grid-template-columns:1fr;gap:10px}
  .cta-actions .btn{width:100%}
  .session-modal{padding:10px}
  .session-window{max-height:94vh}
  .session-head,.session-toggle-wrap,.session-body,.session-controls{padding-left:16px;padding-right:16px}
  .session-toggle-wrap{display:grid;gap:10px}
  .session-mode-toggle{width:100%}
  .state-row,.slot-grid,.llm-cost-grid,.flow-strip{grid-template-columns:1fr}
  .candidate-row{grid-template-columns:58px 96px minmax(0,1fr)}
  .session-controls{display:grid}
  .latency-grid{grid-template-columns:1fr}
  .session-control-buttons{display:grid;grid-template-columns:1fr 1fr}
}