/* ===== Shared structure (theme files override variables) ===== */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth;overflow-x:clip}
body{margin:0;background:var(--bg);color:var(--ink);font:400 17px/1.6 var(--fb);overflow-x:clip;-webkit-font-smoothing:antialiased}
img,svg{display:block;max-width:100%}
a{color:inherit}
h1,h2,h3,h4{font-family:var(--fh);line-height:1.05;margin:0;letter-spacing:var(--track,-.02em);font-weight:var(--hw,700)}
p{margin:0}
.visually-hidden{position:absolute!important;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}
.skip{position:absolute;left:12px;top:-60px;z-index:100;background:var(--accent);color:var(--accent-ink);padding:10px 14px;border-radius:10px;font-weight:600}
.skip:focus{top:12px}
:focus-visible{outline:2px solid var(--accent);outline-offset:3px}
.wrap{width:min(1180px,100% - 48px);margin-inline:auto}

/* header */
.site-header{position:fixed;inset:0 0 auto;z-index:50;transition:background .3s,backdrop-filter .3s,border-color .3s;border-bottom:1px solid transparent}
.site-header.scrolled{background:var(--hdr);backdrop-filter:blur(14px) saturate(1.3);-webkit-backdrop-filter:blur(14px) saturate(1.3);border-color:var(--line)}
.hdr{display:flex;align-items:center;gap:24px;height:72px}
.brand img{height:34px;width:auto}
.nav{display:flex;gap:4px;margin-left:auto}
.nav a{text-decoration:none;font-size:15px;font-weight:500;padding:8px 12px;border-radius:999px;color:var(--ink);opacity:.82;transition:opacity .2s,background .2s}
.nav a:hover{opacity:1;background:var(--hover)}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:10px;text-decoration:none;font-weight:600;font-size:16px;padding:14px 24px;border-radius:var(--btn-r,999px);border:1px solid transparent;transition:transform .2s,box-shadow .2s,background .2s;cursor:pointer;white-space:nowrap}
.btn:hover{transform:translateY(-2px)}
.btn-p{background:var(--accent);color:var(--accent-ink);box-shadow:var(--btn-shadow,none)}
.btn-g{background:var(--ghost);color:var(--ink);border-color:var(--line)}
.btn svg{width:18px;height:18px}
.hdr .btn{padding:10px 18px;font-size:15px}
.menu-btn{display:none;margin-left:auto;width:46px;height:46px;border-radius:14px;border:1px solid var(--line);background:var(--ghost);color:var(--ink);cursor:pointer;position:relative}
.menu-btn span{position:absolute;left:13px;right:13px;height:2px;background:currentColor;border-radius:2px;transition:transform .3s,opacity .3s}
.menu-btn span:nth-child(1){top:16px}.menu-btn span:nth-child(2){top:22px}.menu-btn span:nth-child(3){top:28px}
.menu-open .menu-btn span:nth-child(1){transform:translateY(6px) rotate(45deg)}
.menu-open .menu-btn span:nth-child(2){opacity:0}
.menu-open .menu-btn span:nth-child(3){transform:translateY(-6px) rotate(-45deg)}
.mnav{position:fixed;inset:72px 0 0;z-index:49;background:var(--bg);padding:24px;display:flex;flex-direction:column;gap:4px;transform:translateY(-12px);opacity:0;visibility:hidden;transition:.3s}
.mnav a{font-family:var(--fh);font-size:30px;font-weight:600;text-decoration:none;padding:10px 4px;border-bottom:1px solid var(--line)}
.mnav .btn{margin-top:20px;font-family:var(--fb);font-size:17px}
.menu-open .mnav{opacity:1;visibility:visible;transform:none}
.menu-open{overflow:hidden}

/* 3D stage */
#gl{position:fixed;inset:0;width:100%;height:100%;z-index:0;display:block;outline:none}
.poster{position:fixed;inset:0;z-index:-1;background:var(--poster)}
main,footer{position:relative;z-index:1}
.story{position:relative;pointer-events:none}
.story a,.story .card,.story button{pointer-events:auto}
.hero{position:relative}
.chap{min-height:100vh;min-height:100svh;display:flex;align-items:center;padding:110px 0 70px}
.chap .wrap{display:flex}
.chap[data-side=r] .wrap{justify-content:flex-end}
.chap[data-side=c] .wrap{justify-content:center;text-align:center}
.card{max-width:480px;padding:30px 32px;border-radius:var(--card-r,24px);background:var(--glass);border:1px solid var(--line);backdrop-filter:blur(16px) saturate(1.2);-webkit-backdrop-filter:blur(16px) saturate(1.2);opacity:0;transform:translateY(34px);transition:opacity .8s cubic-bezier(.2,.7,.2,1),transform .8s cubic-bezier(.2,.7,.2,1)}
.chap.on .card{opacity:1;transform:none}
.chap .card h2{font-size:clamp(30px,3.4vw,46px);margin:12px 0 14px}
.chap .card p{color:var(--muted)}
.eyebrow{display:inline-flex;align-items:center;gap:8px;font-size:13px;font-weight:600;letter-spacing:.08em;text-transform:uppercase;color:var(--accent-t)}
.eyebrow::before{content:"";width:8px;height:8px;border-radius:50%;background:var(--accent);box-shadow:0 0 12px var(--accent)}
.hero .card{max-width:620px;background:none;border:0;backdrop-filter:none;-webkit-backdrop-filter:none;padding:0}
.hero h1{font-size:clamp(46px,6vw,88px);margin:18px 0 20px}
.hero .lead{font-size:clamp(18px,1.5vw,21px);color:var(--muted);max-width:520px}
.cta{display:flex;flex-wrap:wrap;gap:12px;margin-top:30px}
.tagline{margin-top:18px;font-size:14px;color:var(--muted)}
.sample-note{display:inline-block;margin-top:14px;font-size:12px;letter-spacing:.06em;text-transform:uppercase;color:var(--muted);border:1px solid var(--line);padding:5px 10px;border-radius:999px}
.rail{position:fixed;right:22px;top:50%;transform:translateY(-50%);z-index:5;display:flex;flex-direction:column;gap:10px;transition:opacity .4s}
.rail i{width:6px;height:6px;border-radius:50%;background:var(--ink);opacity:.25;transition:.3s}
.rail i.on{opacity:1;background:var(--accent);height:22px;border-radius:4px}
.rail.off{opacity:0;pointer-events:none}
.scroll-hint{position:absolute;left:50%;bottom:26px;transform:translateX(-50%);font-size:12px;letter-spacing:.2em;text-transform:uppercase;color:var(--muted);display:flex;flex-direction:column;align-items:center;gap:8px}
.scroll-hint::after{content:"";width:1px;height:38px;background:linear-gradient(var(--muted),transparent);animation:hint 2s infinite}
@keyframes hint{0%{transform:scaleY(0);transform-origin:top}50%{transform:scaleY(1);transform-origin:top}51%{transform-origin:bottom}100%{transform:scaleY(0);transform-origin:bottom}}

/* content sections */
.sec{position:relative;background:var(--bg);padding:120px 0}
.sec.alt{background:var(--bg2)}
.sec-head{max-width:760px;margin-bottom:56px}
.sec-head h2{font-size:clamp(36px,4.4vw,62px);margin:14px 0 18px}
.sec-head h2 em,.hero h1 em,.contact h2 em{font-style:normal;color:var(--accent-t)}
.lead{font-size:19px;color:var(--muted)}
.grid4{display:grid;grid-template-columns:repeat(4,1fr);gap:18px}
.tile{position:relative;padding:28px;border-radius:var(--card-r,24px);background:var(--card);border:1px solid var(--line);overflow:hidden}
.tile h3{font-size:24px;margin:18px 0 10px}
.tile p{color:var(--muted);font-size:16px}
.ico{width:52px;height:52px;border-radius:16px;display:grid;place-items:center;background:var(--ico-bg);color:var(--ico)}
.ico svg{width:26px;height:26px}
.price-tag{display:inline-block;margin-top:18px;font-weight:700;font-size:15px;color:var(--accent-t)}
.steps{list-style:none;margin:0;padding:0;display:grid;grid-template-columns:repeat(4,1fr);gap:18px;counter-reset:s}
.step{padding:28px;border-radius:var(--card-r,24px);background:var(--card);border:1px solid var(--line)}
.step .n{font-family:var(--fh);font-size:15px;font-weight:700;width:44px;height:44px;border-radius:50%;display:grid;place-items:center;background:var(--accent);color:var(--accent-ink)}
.step h3{font-size:24px;margin:20px 0 10px}
.step p{color:var(--muted);font-size:16px}
.demo-band{margin-top:22px;padding:28px 32px;border-radius:var(--card-r,24px);display:flex;flex-wrap:wrap;gap:20px;align-items:center;justify-content:space-between;background:var(--band);color:var(--band-ink)}
.demo-band h3{font-size:clamp(22px,2.2vw,30px)}
.demo-band p{opacity:.8;margin-top:6px}
.pricing{display:grid;grid-template-columns:1.25fr 1fr;gap:18px}
.calc{padding:36px;border-radius:var(--card-r,24px);background:var(--card);border:1px solid var(--line)}
.calc-top{display:flex;justify-content:space-between;align-items:flex-end;gap:16px;flex-wrap:wrap}
.calc label{font-weight:600}
.calc output{display:block}
#pages-out{font-size:15px;color:var(--muted)}
#price-out{font-family:var(--fh);font-size:clamp(56px,6vw,84px);line-height:1;font-weight:700;color:var(--ink)}
input[type=range]{-webkit-appearance:none;appearance:none;width:100%;height:8px;border-radius:99px;margin:28px 0 10px;background:linear-gradient(90deg,var(--accent) var(--f,0%),var(--track-bg) var(--f,0%));outline-offset:6px}
input[type=range]::-webkit-slider-thumb{-webkit-appearance:none;width:28px;height:28px;border-radius:50%;background:var(--thumb,#fff);border:4px solid var(--accent);box-shadow:0 4px 14px rgba(0,0,0,.3);cursor:grab}
input[type=range]::-moz-range-thumb{width:22px;height:22px;border-radius:50%;background:var(--thumb,#fff);border:4px solid var(--accent);cursor:grab}
.range-scale{display:flex;justify-content:space-between;font-size:13px;color:var(--muted)}
.examples{display:grid;grid-template-columns:repeat(4,1fr);gap:10px;margin-top:28px}
.examples div{padding:14px;border-radius:14px;border:1px solid var(--line);text-align:center;font-size:14px;color:var(--muted)}
.examples b{display:block;font-family:var(--fh);font-size:24px;color:var(--ink)}
.calc .fine{margin-top:22px;font-size:14px;color:var(--muted)}
.side{display:grid;gap:18px}
.side .tile h3{margin-top:0;font-size:21px}
.split{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin-top:14px}
.split div{padding:14px;border-radius:14px;background:var(--hover);font-size:14px;color:var(--muted)}
.split b{display:block;font-family:var(--fh);font-size:30px;color:var(--accent-t)}
.founder{display:grid;grid-template-columns:auto 1fr;gap:44px;align-items:center;max-width:980px;margin:0 auto}
.avatar{width:180px;height:180px;border-radius:50%;display:grid;place-items:center;font-family:var(--fh);font-size:84px;font-weight:700;background:var(--av-bg);color:var(--av-ink);box-shadow:var(--av-shadow,none)}
.founder blockquote{margin:0;font-family:var(--fq,var(--fh));font-size:clamp(22px,2.3vw,31px);line-height:1.35;font-weight:500;letter-spacing:-.01em}
.founder blockquote em{font-style:normal;color:var(--accent-t)}
.founder figcaption{margin-top:22px;color:var(--muted)}
.founder figcaption b{display:block;color:var(--ink);font-size:18px}
.faq{display:grid;grid-template-columns:.8fr 1.2fr;gap:56px;align-items:start}
.faq details{border-bottom:1px solid var(--line)}
.faq summary{list-style:none;cursor:pointer;display:flex;justify-content:space-between;gap:20px;padding:22px 0;font-family:var(--fh);font-size:21px;font-weight:600}
.faq summary::-webkit-details-marker{display:none}
.plus{flex:none;width:28px;height:28px;border-radius:50%;border:1px solid var(--line);position:relative;transition:transform .3s}
.plus::before,.plus::after{content:"";position:absolute;left:8px;right:8px;top:13px;height:1.5px;background:currentColor}
.plus::after{transform:rotate(90deg);transition:transform .3s}
details[open] .plus::after{transform:rotate(0)}
.faq details p{padding:0 0 22px;color:var(--muted);max-width:640px}
.contact{text-align:center;max-width:860px;margin:0 auto}
.contact h2{font-size:clamp(40px,5.4vw,76px);margin:16px 0 20px}
.contact .cta{justify-content:center}
.contact-lines{display:flex;flex-wrap:wrap;justify-content:center;gap:10px 28px;margin-top:26px;color:var(--muted);font-size:15px}
.contact-lines a{color:var(--ink);text-decoration:none;font-weight:600}
.site-footer{background:var(--foot);color:var(--foot-ink);padding:64px 0 36px;border-top:1px solid var(--line)}
.foot{display:grid;grid-template-columns:1.4fr 1fr 1fr;gap:40px}
.foot p{opacity:.7;font-size:15px;margin-top:14px;max-width:340px}
.foot h4{font-family:var(--fb);font-size:13px;letter-spacing:.1em;text-transform:uppercase;opacity:.6;margin-bottom:14px}
.foot ul{list-style:none;margin:0;padding:0;display:grid;gap:8px;font-size:15px}
.foot a{text-decoration:none;opacity:.85}.foot a:hover{opacity:1}
.foot-b{display:flex;flex-wrap:wrap;justify-content:space-between;gap:12px;margin-top:48px;padding-top:24px;border-top:1px solid var(--line);font-size:13px;opacity:.65}
.wa-float{position:fixed;right:20px;bottom:20px;z-index:60;width:58px;height:58px;border-radius:50%;display:grid;place-items:center;background:#25D366;color:#fff;box-shadow:0 10px 30px rgba(0,0,0,.3);transition:transform .2s}
.wa-float:hover{transform:scale(1.07)}
.wa-float svg{width:30px;height:30px}
.reveal{opacity:0;transform:translateY(26px);transition:opacity .8s cubic-bezier(.2,.7,.2,1) var(--d,0s),transform .8s cubic-bezier(.2,.7,.2,1) var(--d,0s)}
.reveal.in{opacity:1;transform:none}
.labels{position:fixed;inset:0;z-index:2;pointer-events:none;overflow:hidden}

@media (max-width:1060px){.grid4,.steps{grid-template-columns:1fr 1fr}.pricing,.faq{grid-template-columns:1fr}.faq{gap:20px}}
@media (max-width:860px){.nav,.hdr>.btn{display:none}.menu-btn{display:block}.rail{display:none}}
@media (max-width:760px){
  body{font-size:16px}
  .wrap{width:calc(100% - 36px)}
  .chap{align-items:flex-end;padding:90px 0 40px}
  .chap .wrap{justify-content:center!important}
  .card{padding:22px;max-width:none;width:100%}
  .hero{align-items:flex-end}
  .hero .card{padding:0}
  .hero h1{font-size:42px}
  .hero .tagline{display:none}
  .hero .lead{font-size:16px}
  .hero .cta{margin-top:22px}
  .sec{padding:80px 0}
  .grid4,.steps{grid-template-columns:1fr}
  .examples{grid-template-columns:1fr 1fr}
  .calc{padding:24px}
  .founder{grid-template-columns:1fr;text-align:center;gap:24px}
  .avatar{width:120px;height:120px;font-size:56px;margin:0 auto}
  .foot{grid-template-columns:1fr}
  .btn{padding:14px 20px}
  .cta .btn{flex:1 1 100%}
  .scroll-hint{display:none}
}
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{animation:none!important;transition-duration:.01ms!important}
  .reveal,.card{opacity:1;transform:none}
}

/* ===== Concept A: device reveal (dark premium) ===== */
@font-face{font-family:"InterV";src:url(../fonts/inter-latin-wght-normal.woff2) format("woff2");font-weight:100 900;font-display:swap}
.theme-a{--bg:#050506;--bg2:#0b0b0d;--ink:#f5f5f7;--muted:#a1a1a6;--line:rgba(255,255,255,.1);--card:linear-gradient(180deg,rgba(255,255,255,.055),rgba(255,255,255,.02));--glass:rgba(12,12,14,.55);--hdr:rgba(5,5,6,.72);--hover:rgba(255,255,255,.06);--ghost:rgba(255,255,255,.06);
  --accent:#f5f5f7;--accent-ink:#050506;--accent-t:#a9c1ff;--fh:"InterV",system-ui,sans-serif;--fb:"InterV",system-ui,sans-serif;--hw:650;--track:-.035em;
  --ico-bg:rgba(169,193,255,.12);--ico:#a9c1ff;--band:linear-gradient(110deg,#1b2140,#0e0f16 60%);--band-ink:#f5f5f7;--track-bg:rgba(255,255,255,.14);--thumb:#050506;
  --av-bg:radial-gradient(circle at 30% 25%,#3a3f52,#0d0e12 70%);--av-ink:#f5f5f7;--av-shadow:0 0 0 1px rgba(255,255,255,.12),0 30px 80px rgba(120,150,255,.25);--foot:#000;--foot-ink:#f5f5f7;
  --poster:radial-gradient(120% 80% at 70% 40%,#1a1d2b 0%,#050506 60%)}
.theme-a .hero h1{font-size:clamp(50px,6.6vw,104px);letter-spacing:-.05em;line-height:.98}
.theme-a .hero h1 em,.theme-a .sec-head h2 em,.theme-a .contact h2 em{font-style:normal;background:linear-gradient(100deg,#e6ecff 0%,#9db8ff 45%,#c7a6ff 100%);-webkit-background-clip:text;background-clip:text;color:transparent}
.theme-a .eyebrow{color:#a9c1ff}
.theme-a .eyebrow::before{background:#a9c1ff;box-shadow:0 0 12px #a9c1ff}
.theme-a .btn-g{background:rgba(255,255,255,.08)}
.theme-a .chap .card{background:rgba(10,10,12,.5)}
.theme-a .hero .card{background:none}
.theme-a .step .n{background:linear-gradient(135deg,#e6ecff,#9db8ff);color:#050506}
.theme-a .price-tag,.theme-a .split b{color:#a9c1ff}
.theme-a input[type=range]{background:linear-gradient(90deg,#9db8ff var(--f,0%),var(--track-bg) var(--f,0%))}
.theme-a input[type=range]::-webkit-slider-thumb{border-color:#9db8ff;background:#fff}
.theme-a .sec{background:var(--bg)}
.theme-a .sec.alt{background:radial-gradient(80% 60% at 50% 0%,#12141c,var(--bg2) 70%)}
.theme-a .tile,.theme-a .step,.theme-a .calc{box-shadow:inset 0 1px 0 rgba(255,255,255,.06)}
.screen-cap{position:fixed;left:50%;bottom:22px;transform:translateX(-50%);z-index:3;font-size:12px;letter-spacing:.08em;text-transform:uppercase;color:#a1a1a6;transition:opacity .4s;pointer-events:none}
@media (max-width:760px){.theme-a .hero h1{font-size:44px}.theme-a .chap .card{background:rgba(10,10,12,.72)}.theme-a .hero .card{background:none}.theme-a .chap.hero{background:linear-gradient(180deg,transparent 38%,rgba(5,5,6,.85) 58%)}}