/* ============================================================
   Quelm ring-sizer demo — ported from MindScape /baseline/try
   (.bt-* classes kept verbatim where possible; tokens inherit
   from site.css :root — Fraunces/Inter/IBM Plex Mono).
   ============================================================ */
.bt{--panel:#111A2C;--line:#1D2A42;
  background:var(--abyss);color:var(--bone);font-family:var(--sans);line-height:1.6;-webkit-font-smoothing:antialiased}
.bt h1,.bt h2{font-family:var(--serif);font-weight:340;letter-spacing:-.01em;line-height:1.12;margin:0}
.bt a{color:inherit}
.bt :focus-visible{outline:2px solid var(--pulse);outline-offset:3px;border-radius:4px}
.bt button{font-family:var(--sans);cursor:pointer}
.bt-wrap{max-width:960px;margin:0 auto;padding:0 22px}
.bt-eyebrow{font-family:var(--mono);font-size:12px;letter-spacing:.28em;color:var(--pulse);text-transform:uppercase}
.bt-h2{font-size:clamp(26px,4vw,36px);margin:14px 0 6px}

/* hero */
.bt-hero{position:relative;padding:clamp(160px,22vh,220px) 0 clamp(64px,9vh,88px);overflow:hidden;background:radial-gradient(120% 90% at 50% -20%,rgba(94,234,212,.12),transparent 60%)}
.bt-hero #horizon{position:absolute;inset:0;width:100%;height:100%;opacity:.5}
.bt-hero-inner{position:relative;display:grid;grid-template-columns:1.15fr .85fr;gap:40px;align-items:center}
.bt-hero-art{position:relative;border-radius:24px;overflow:hidden;border:1px solid rgba(94,234,212,.18);box-shadow:0 40px 120px -40px rgba(94,234,212,.35)}
.bt-hero-art img{display:block;width:100%;height:auto}
.bt-hero-badge{position:absolute;right:18px;bottom:18px;display:flex;flex-direction:column;align-items:center;justify-content:center;width:74px;height:74px;border-radius:50%;background:rgba(7,13,26,.72);border:1px solid rgba(94,234,212,.5);backdrop-filter:blur(6px);color:var(--pulse)}
.bt-hero-badge span{font-family:var(--serif);font-size:26px;line-height:1}
.bt-hero-badge small{font-family:var(--mono);font-size:9px;letter-spacing:.18em;text-transform:uppercase;color:var(--dim);margin-top:2px}
.bt-hero h1{font-size:clamp(36px,6vw,62px);max-width:17ch;margin:18px 0 18px}
.bt-hero p{color:var(--dim);font-size:17px;max-width:54ch;margin:0}
.bt-hero-ctas{display:flex;align-items:center;gap:18px;flex-wrap:wrap;margin-top:30px}
.bt-hero-note{font-family:var(--mono);font-size:12px;letter-spacing:.06em;color:var(--dim)}
.bt .bt-cta{display:inline-block;background:var(--pulse);color:#06211C;font-weight:700;padding:15px 28px;border-radius:14px;text-decoration:none;font-size:16px;box-shadow:0 14px 40px -14px rgba(94,234,212,.7);transition:transform .18s var(--ease-spring),box-shadow .18s var(--ease-spring)}
.bt .bt-cta:hover{transform:translateY(-1px);box-shadow:0 18px 48px -14px rgba(94,234,212,.85)}

/* sizer */
.bt-sizer{background:var(--ink);border-top:1px solid var(--line);border-bottom:1px solid var(--line);padding:clamp(56px,8vh,80px) 0;scroll-margin-top:92px}
.bt-tabs{display:flex;gap:10px;margin:22px 0 22px;flex-wrap:wrap}
.bt-tab{background:transparent;border:1px solid var(--line);color:var(--dim);border-radius:999px;padding:12px 20px;font-size:14.5px;font-weight:600;display:inline-flex;align-items:center;gap:8px;transition:border-color .18s,color .18s,background .18s}
.bt-tab:hover{color:var(--bone);border-color:#2a3b5c}
.bt-tab[aria-selected="true"]{border-color:var(--pulse);color:var(--pulse);background:rgba(94,234,212,.07)}
.bt-tab-ico{display:inline-flex;align-items:center;line-height:1}
.bt-panel{background:var(--panel);border:1px solid var(--line);border-radius:20px;padding:28px}
.bt-panel h3{font-family:var(--mono);font-size:12px;letter-spacing:.22em;color:var(--dim);margin:0 0 16px;font-weight:500;text-transform:uppercase}
.bt-steps{color:var(--dim);font-size:14.5px;margin:0 0 18px;padding-left:0;list-style:none;display:grid;gap:6px;counter-reset:s}
.bt-steps li{counter-increment:s;display:flex;gap:12px;align-items:baseline}
.bt-steps li::before{content:counter(s);font-family:var(--mono);font-size:11px;color:var(--pulse);border:1px solid rgba(94,234,212,.4);border-radius:999px;width:22px;height:22px;display:inline-flex;align-items:center;justify-content:center;flex:none;transform:translateY(-1px)}
.bt-steps b{color:var(--bone);font-weight:600}
.bt video,.bt #still{width:100%;border-radius:14px;background:#000;display:block}
.bt #still{max-height:70vh;object-fit:contain}
#camHolder{position:relative;border-radius:14px;overflow:hidden;background:linear-gradient(160deg,#0B1220,#131F35);width:100%;max-width:760px;min-height:0;max-height:440px;aspect-ratio:4/3;margin:0 auto}
#camHolder video{width:100%;height:100%;min-height:240px;object-fit:cover}
.bt-cam-state{position:absolute;inset:0;display:flex;align-items:center;justify-content:center;text-align:center;color:var(--dim);font-size:14px;padding:28px;pointer-events:none}
.bt-cam-state>div{display:none;flex-direction:column;gap:8px;max-width:34ch;align-items:center}
.bt-cam-state strong{color:var(--bone);font-size:15px}
#camHolder[data-cam-state="idle"] .bt-cam-idle{display:flex}
#camHolder[data-cam-state="pending"] .bt-cam-pending{display:flex}
.bt-cam-glyph{display:inline-flex;line-height:1;margin-bottom:6px;color:var(--pulse);opacity:.85}
#camHolder[data-cam-state="denied"] .bt-cam-denied{display:flex}
#camHolder[data-cam-state="live"] .bt-cam-state{display:none}
#camHolder[data-cam-state="denied"] video,#camHolder[data-cam-state="pending"] video,#camHolder[data-cam-state="idle"] video{opacity:0}
.bt-spinner{width:26px;height:26px;border-radius:50%;border:2px solid rgba(94,234,212,.25);border-top-color:var(--pulse);animation:bt-spin 1s linear infinite;margin-bottom:4px}
@keyframes bt-spin{to{transform:rotate(360deg)}}
.bt-cam-guide{position:absolute;inset:0;display:none;align-items:center;justify-content:center;pointer-events:none}
#camHolder[data-cam-state="live"] .bt-cam-guide{display:flex}
.bt-guide-card{width:62%;aspect-ratio:1.586;border:1.5px dashed rgba(94,234,212,.55);border-radius:10px;display:flex;align-items:flex-end;justify-content:flex-end;padding:8px;box-shadow:0 0 0 9999px rgba(7,13,26,.18)}
.bt-guide-card span{font-family:var(--mono);font-size:11px;letter-spacing:.2em;text-transform:uppercase;color:rgba(94,234,212,.8)}
.bt-controls{display:flex;gap:10px;flex-wrap:wrap;margin-top:16px;align-items:center}
.bt-btn{background:var(--pulse);color:#06211C;border:0;border-radius:12px;padding:13px 22px;font-weight:700;font-size:15px;transition:transform .15s,filter .15s}
.bt-btn:hover{filter:brightness(1.05);transform:translateY(-1px)}
.bt-btn:active{transform:translateY(0)}
.bt-ghost{background:transparent;color:var(--pulse);border:1px solid rgba(94,234,212,.6)}
.bt-hint{font-size:13px;color:var(--dim);flex-basis:100%}
.bt-hint.is-warn{color:var(--ember)}
.bt-legend{display:flex;gap:18px;font-size:13px;color:var(--dim);margin-top:12px;flex-wrap:wrap}
.bt-dot{display:inline-block;width:10px;height:10px;border-radius:50%;margin-right:6px;vertical-align:middle}
#stage{position:relative;touch-action:pan-y;user-select:none;border-radius:14px;overflow:visible}
.bt-cal{position:absolute;top:0;bottom:0;width:2px;background:var(--pulse);cursor:grab;transform:translateX(-1px);touch-action:none}
.bt-cal.is-dragging{cursor:grabbing}
.bt-cal::before{content:"";position:absolute;top:0;bottom:0;left:-14px;width:30px}
.bt-cal::after{content:"";position:absolute;top:50%;left:50%;transform:translate(-50%,-50%);width:38px;height:38px;border:2px solid var(--pulse);border-radius:50%;background:rgba(94,234,212,.14);box-shadow:0 0 0 6px rgba(94,234,212,.08),0 6px 18px rgba(0,0,0,.45);transition:transform .12s,box-shadow .12s}
.bt-cal.is-dragging::after,.bt-cal:focus-visible::after{transform:translate(-50%,-50%) scale(1.18);box-shadow:0 0 0 10px rgba(94,234,212,.14),0 10px 24px rgba(0,0,0,.5)}
.bt-cal.f{background:var(--ember)}
.bt-cal.f::after{border-color:var(--ember);background:rgba(217,142,85,.14);box-shadow:0 0 0 6px rgba(217,142,85,.08),0 6px 18px rgba(0,0,0,.45)}
.bt-cal.f.is-dragging::after,.bt-cal.f:focus-visible::after{box-shadow:0 0 0 10px rgba(217,142,85,.16),0 10px 24px rgba(0,0,0,.5)}
.bt-tag{position:absolute;top:10px;left:50%;transform:translateX(-50%);font-family:var(--mono);font-size:10px;letter-spacing:.18em;text-transform:uppercase;color:#06211C;background:var(--pulse);border-radius:999px;padding:3px 7px;white-space:nowrap}
.bt-cal.f .bt-tag{background:var(--ember);top:auto;bottom:10px}
#f1 .bt-tag{left:auto;right:8px;transform:none}
#f2 .bt-tag{left:8px;transform:none}
#c1 .bt-tag{left:8px;transform:none}
#c2 .bt-tag{left:auto;right:8px;transform:none}
.bt-readout{display:flex;align-items:baseline;justify-content:space-between;gap:12px;margin-top:14px;padding:12px 16px;border:1px solid var(--line);border-radius:12px;background:rgba(7,13,26,.6)}
.bt-readout-label{font-family:var(--mono);font-size:11px;letter-spacing:.2em;text-transform:uppercase;color:var(--dim)}
.bt-readout-value{font-family:var(--mono);font-size:15px;color:var(--pulse)}
.bt input[type=range]{width:100%;accent-color:var(--pulse);margin:4px 0 6px}
.bt label{font-size:13px;color:var(--dim);display:block;margin:16px 0 6px}
.bt select{background:var(--ink);border:1px solid var(--line);color:var(--bone);border-radius:12px;padding:12px 14px;font-size:15px;width:100%}
.bt-circle-stage{position:relative;height:360px;background:var(--ink);border:1px solid var(--line);border-radius:14px;overflow:hidden;background-image:radial-gradient(rgba(94,234,212,.12) 1px,transparent 1px);background-size:18px 18px}
.bt-card-outline{position:absolute;left:50%;top:24px;transform:translateX(-50%);height:64px;border:2px dashed var(--dim);border-radius:8px;display:flex;align-items:center;justify-content:center}
.bt-card-outline span{font-family:var(--mono);font-size:10px;letter-spacing:.18em;text-transform:uppercase;color:var(--dim)}
.bt-ring-circle{position:absolute;left:50%;top:62%;transform:translate(-50%,-50%);border:2.5px solid var(--pulse);border-radius:50%;box-shadow:0 0 24px rgba(94,234,212,.35),inset 0 0 18px rgba(94,234,212,.12)}

/* result */
.bt-result{display:none;position:relative;overflow:hidden;text-align:center;padding:40px 24px 34px;border:1px solid rgba(94,234,212,.55);border-radius:22px;margin-top:24px;background:linear-gradient(180deg,rgba(94,234,212,.08),rgba(7,13,26,.2))}
.bt-result.is-in{animation:bt-in .55s cubic-bezier(.2,.9,.3,1.2)}
@keyframes bt-in{from{opacity:0;transform:translateY(14px) scale(.98)}to{opacity:1;transform:none}}
.bt-result-glow{position:absolute;inset:-40% -20% auto;height:140%;background:radial-gradient(50% 40% at 50% 40%,rgba(94,234,212,.22),transparent 70%);pointer-events:none}
.bt-result-ring{position:absolute;left:50%;top:118px;width:210px;height:210px;transform:translateX(-50%);border-radius:50%;border:1.5px solid rgba(94,234,212,.22);box-shadow:inset 0 0 40px rgba(94,234,212,.08),0 0 60px rgba(94,234,212,.08);pointer-events:none}
.bt-size{position:relative;font-family:var(--serif);font-size:clamp(72px,14vw,104px);line-height:1;color:var(--pulse);margin:12px 0 6px;text-shadow:0 0 36px rgba(94,234,212,.35)}
.bt-mm{font-family:var(--mono);font-size:13px;color:var(--dim)}
.bt-result p{max-width:46ch;margin:16px auto 0;color:var(--dim);font-size:15px;position:relative}
.bt-result .bt-cta{margin-top:22px;position:relative}
.bt-result .bt-eyebrow{position:relative;font-size:11px;letter-spacing:.22em}
.bt-privacy{font-family:var(--mono);font-size:11.5px;color:var(--dim);margin-top:18px;letter-spacing:.04em;position:relative}
.bt-privacy b{color:var(--pulse);font-weight:500}

/* what-you-just-used band */
.bt-band{padding:clamp(56px,8vh,80px) 0;background:var(--slate)}
.bt-band h2{font-size:clamp(26px,4.4vw,38px);margin:12px 0 14px}
.bt-band>.bt-wrap>p{color:var(--dim);max-width:60ch}
.bt-offers{display:grid;grid-template-columns:repeat(3,1fr);gap:18px;margin:30px 0 34px}
@media(max-width:760px){.bt-offers{grid-template-columns:1fr}}
.bt-offers .offer{margin-bottom:0}
.bt-band .cta-row{margin-top:8px}

/* demo chart */
.bt-demo{padding:clamp(64px,9vh,88px) 0}
.bt-demo h2{font-size:clamp(26px,4.4vw,38px);max-width:20ch;margin-top:12px}
.bt-demo .bt-sub{color:var(--dim);margin:12px 0 26px;max-width:56ch}
.bt #arc{width:100%;height:280px;background:var(--panel);border:1px solid var(--line);border-radius:18px;display:block}
.bt-chart-legend{display:flex;gap:18px;flex-wrap:wrap;font-family:var(--mono);font-size:11.5px;letter-spacing:.06em;color:var(--dim);margin-bottom:10px}
.bt-chart-legend i{display:inline-block;width:18px;height:3px;border-radius:2px;margin-right:8px;vertical-align:middle}
.bt-illustrative{font-family:var(--mono);font-size:11.5px;color:var(--dim);margin-top:10px;letter-spacing:.04em}
.bt-demo-cta{margin-top:22px}
.bt-demo-cta a{color:var(--pulse);font-weight:600;text-decoration:none}
@media (prefers-reduced-motion: reduce){.bt-hero #horizon{display:none}.bt-result.is-in{animation:none}.bt-spinner{animation:none}}
@media (max-width:880px){.bt-hero-inner{grid-template-columns:1fr;gap:26px}.bt-hero-art{max-width:460px}}
@media (max-width:640px){.bt-readout{flex-direction:column;align-items:flex-start;gap:4px}.bt-readout-value{font-size:16px}.bt-panel{padding:20px 16px}.bt-hero{padding-top:130px}.bt-circle-stage{height:320px}.bt-hero-art{display:none}}