/* Shared shell + components for BackEngine FAQ pages.
   Mirrors the system in "How BackEngine Works.html". */
:root{
  --ink:#0b0d12;
  --muted:rgba(11,13,18,.58);
  --faint:rgba(11,13,18,.38);
  --line:rgba(11,13,18,.10);
  --line-strong:rgba(11,13,18,.22);
  --accent:#2f5fe0;
  --accent2:#0e9d86;
  --paper:#fff;
  --paper2:#f6f7f9;
  --font:"Helvetica Neue",Helvetica,Arial,sans-serif;
  --mono:"SF Mono",ui-monospace,"Roboto Mono",Menlo,monospace;
}
*{box-sizing:border-box;margin:0;padding:0;}
html{scroll-behavior:smooth;overflow-x:clip;}
body{background:var(--paper);color:var(--ink);font-family:var(--font);-webkit-font-smoothing:antialiased;overflow-x:clip;}
a{text-decoration:none;color:inherit;}
::selection{background:var(--accent);color:#fff;}
@media (prefers-reduced-motion:reduce){*{animation:none!important;transition:none!important;}}

/* ===== site header ===== */
.topbar{position:sticky;top:0;z-index:30;display:flex;align-items:center;gap:48px;
  padding:20px 7vw;background:rgba(255,255,255,.86);backdrop-filter:blur(14px);}
.topbar .logo img{height:25px;display:block;}
.topnav{display:flex;gap:32px;font-size:14.5px;color:var(--ink);}
.topnav a{opacity:.82;transition:opacity .15s;}
.topnav a:hover{opacity:1;}
.top-actions{margin-left:auto;display:flex;align-items:center;gap:22px;flex-shrink:0;}
.top-link{font-size:14.5px;font-weight:500;color:var(--ink);opacity:.82;transition:opacity .15s;}
.top-link:hover{opacity:1;}
.top-cta{font-size:14px;font-weight:600;color:#fff;background:var(--ink);border-radius:100px;
  padding:10px 18px;white-space:nowrap;transition:transform .2s;}
.top-cta:hover{transform:translateY(-1px);}

/* ===== breadcrumb bar ===== */
.crumbbar{position:sticky;top:65px;z-index:29;padding:13px 7vw;
  background:rgba(255,255,255,.86);backdrop-filter:blur(14px);border-bottom:1px solid var(--line);}
.crumb{display:flex;align-items:center;gap:11px;font-size:13.5px;color:var(--faint);}
.crumb a{color:var(--muted);transition:color .2s;}
.crumb a:hover{color:var(--accent);}
.crumb .sep{opacity:.5;}
.qmenu{position:relative;}
.qtrigger{display:inline-flex;align-items:center;gap:7px;color:var(--ink);font-weight:500;font-size:13.5px;
  background:none;border:0;cursor:pointer;font-family:inherit;padding:0;}
.qtrigger .chev{font-size:9px;color:var(--faint);transition:transform .2s;}
.qmenu.open .qtrigger .chev{transform:rotate(180deg);}
.qpop{position:absolute;top:calc(100% + 13px);left:-14px;z-index:40;width:min(380px,86vw);
  background:#fff;border:1px solid var(--line);border-radius:14px;box-shadow:0 24px 60px -20px rgba(11,13,18,.4);
  padding:7px;opacity:0;visibility:hidden;transform:translateY(-6px);transition:.18s;}
.qmenu.open .qpop{opacity:1;visibility:visible;transform:translateY(0);}
.qpop a{display:grid;grid-template-columns:24px 1fr;gap:9px;align-items:baseline;padding:11px 12px;border-radius:9px;
  font-size:14px;line-height:1.3;color:var(--muted);transition:background .15s,color .15s;}
.qpop a:hover{background:var(--paper2);color:var(--ink);}
.qpop a .qn{font-family:var(--mono);font-size:11px;color:var(--faint);}
.qpop a.cur{color:var(--ink);font-weight:700;background:rgba(47,95,224,.06);}
.qpop a.cur .qn{color:var(--accent);}

.main{max-width:1060px;margin:0 auto;padding:clamp(52px,7vh,88px) 7vw 120px;}

/* ===== page title ===== */
/* no border: the first step's "01" rule below does the separating */
.pagehead{position:relative;padding-bottom:0;margin-bottom:clamp(38px,5.5vh,60px);}
.pagehead::before{content:"";position:absolute;z-index:0;left:-9vw;right:-9vw;top:-110px;height:430px;pointer-events:none;
  background:
    radial-gradient(42% 64% at 14% 20%,rgba(47,95,224,.12),transparent 70%),
    radial-gradient(38% 56% at 88% 0,rgba(14,157,134,.08),transparent 72%);}
.pagehead h1{position:relative;z-index:1;font-size:clamp(38px,5.2vw,68px);line-height:1;font-weight:800;letter-spacing:-.045em;max-width:18ch;}

/* ===== steps ===== */
.step{margin-top:clamp(60px,9vh,104px);}
.step:first-of-type{margin-top:0;}
.step-tag{display:flex;align-items:center;gap:14px;margin-bottom:20px;}
.step-tag .n{font-family:var(--mono);font-size:13px;color:var(--accent);font-variant-numeric:tabular-nums;}
.step-tag .ln{height:1px;flex:1;background:var(--line);}
.step h2{font-size:clamp(27px,3.3vw,40px);font-weight:800;letter-spacing:-.035em;line-height:1.05;margin-bottom:18px;max-width:22ch;}
.step p{font-size:clamp(16px,1.4vw,18.5px);line-height:1.62;color:var(--muted);max-width:62ch;text-wrap:pretty;}
.step p + p{margin-top:13px;}
.step b{color:var(--ink);font-weight:600;}
.viz{margin-top:38px;}

/* ===== panel: generic bordered surface ===== */
.panel{border:1px solid var(--line);border-radius:24px;background:var(--paper2);padding:clamp(26px,3.5vw,44px);}

/* ===== duo: two-column in/out or contrast ===== */
.duo{display:grid;grid-template-columns:1fr 1fr;gap:16px;}
.duo-card{border:1px solid var(--line);border-radius:18px;background:var(--paper2);padding:24px;}
.duo-card.lead-card{border:1.5px solid var(--accent);background:rgba(47,95,224,.04);}
.duo-card.dim-card{border-style:dashed;border-color:var(--line-strong);}
.duo-h{display:flex;align-items:center;justify-content:space-between;gap:10px;margin-bottom:14px;}
.duo-h .who{font-size:16px;font-weight:700;letter-spacing:-.01em;}
.duo-h .scope{font-family:var(--mono);font-size:10.5px;letter-spacing:.1em;text-transform:uppercase;color:var(--faint);text-align:right;}
.lrow{display:flex;align-items:center;gap:10px;font-size:14.5px;padding:11px 0;border-top:1px solid var(--line);}
.lrow:first-of-type{border-top:0;}
.lrow .tick{width:18px;height:18px;border-radius:5px;background:rgba(14,157,134,.14);color:var(--accent2);
  display:flex;align-items:center;justify-content:center;font-size:12px;flex-shrink:0;}
.lrow.locked{color:var(--faint);}
.lrow.locked .tick{background:rgba(11,13,18,.05);position:relative;}
.lrow.locked .tick::after{content:"";width:7px;height:1.5px;border-radius:1px;background:var(--faint);}

/* ===== pills ===== */
.pills{display:flex;flex-wrap:wrap;gap:10px;}
.pill{display:inline-flex;align-items:center;gap:9px;font-size:14.5px;font-weight:600;color:var(--ink);
  background:var(--paper);border:1px solid var(--line-strong);border-radius:100px;padding:10px 18px;}
.pill .d{width:7px;height:7px;border-radius:50%;background:var(--accent2);flex-shrink:0;}

/* ===== tool categories grid ===== */
.tools{display:grid;grid-template-columns:repeat(3,1fr);gap:14px;}
.tool{border:1px solid var(--line);border-radius:16px;background:var(--paper2);padding:20px;
  display:flex;flex-direction:column;gap:9px;transition:border-color .2s,transform .2s;}
.tool:hover{border-color:var(--line-strong);transform:translateY(-3px);}
.tool .tl{font-family:var(--mono);font-size:10.5px;letter-spacing:.12em;text-transform:uppercase;color:var(--accent2);}
.tool .tv{font-size:15.5px;font-weight:600;letter-spacing:-.01em;line-height:1.45;}
.tool .tn{font-size:13px;color:var(--faint);line-height:1.5;}

/* ===== timeline ===== */
.timeline{display:grid;grid-template-columns:repeat(3,1fr);gap:0;border:1px solid var(--line);border-radius:20px;background:var(--paper2);overflow:hidden;}
.tstep{padding:26px 24px;border-left:1px solid var(--line);display:flex;flex-direction:column;gap:10px;}
.tstep:first-child{border-left:0;}
.tstep .tt{font-family:var(--mono);font-size:11px;letter-spacing:.14em;text-transform:uppercase;color:var(--accent);}
.tstep .th{font-size:17px;font-weight:700;letter-spacing:-.015em;}
.tstep .td{font-size:14px;line-height:1.55;color:var(--muted);}

/* ===== big stat ===== */
.stat{display:flex;align-items:baseline;gap:16px;flex-wrap:wrap;}
.stat .sv{font-size:clamp(48px,6vw,76px);font-weight:800;letter-spacing:-.045em;line-height:1;color:var(--accent);}
.stat .sl{font-size:16px;font-weight:600;color:var(--muted);max-width:30ch;line-height:1.45;}

/* ===== slack-style notification card ===== */
.notif{border:1px solid var(--line-strong);border-radius:18px;background:var(--paper);overflow:hidden;max-width:640px;
  box-shadow:0 24px 56px -30px rgba(11,13,18,.4);}
.notif-bar{display:flex;align-items:center;gap:9px;padding:13px 18px;background:var(--paper2);border-bottom:1px solid var(--line);
  font-family:var(--mono);font-size:11.5px;color:var(--faint);letter-spacing:.04em;}
.notif-bar .hash{color:var(--accent);font-weight:700;}
.notif-body{padding:20px 18px;display:flex;gap:13px;}
.notif-body .av{width:32px;height:32px;border-radius:9px;background:var(--accent);color:#fff;flex-shrink:0;
  display:flex;align-items:center;justify-content:center;font-weight:800;font-size:15px;}
.notif-body .msg{font-size:15px;line-height:1.6;color:var(--ink);}
.notif-body .msg .meta{font-size:12.5px;color:var(--faint);margin-bottom:5px;}
.notif-body .msg .meta b{color:var(--ink);font-weight:700;}

/* ===== habit chain ===== */
.chain{display:flex;align-items:center;flex-wrap:wrap;gap:12px;}
.chain .hb{display:inline-flex;align-items:center;gap:9px;font-size:15px;font-weight:600;
  background:var(--paper);border:1px solid var(--line-strong);border-radius:12px;padding:13px 18px;}
.chain .hb.now{border:1.5px solid var(--accent);background:rgba(47,95,224,.05);color:var(--ink);}
.chain .hb.next{color:var(--muted);border-style:dashed;}
.chain .car{color:var(--accent);font-size:18px;}

/* ===== compare (same q / same a) ===== */
.compare{display:grid;grid-template-columns:1fr 1fr;gap:16px;}
.cmp{border-radius:18px;padding:26px;}
.cmp.bad{border:1px dashed var(--line-strong);background:var(--paper2);}
.cmp.good{border:1.5px solid var(--accent);background:rgba(47,95,224,.04);}
.cmp .ch{font-size:15px;font-weight:700;letter-spacing:-.01em;margin-bottom:18px;}
.cmp.bad .ch{color:var(--muted);}
.ask{display:flex;align-items:center;gap:12px;padding:13px 0;border-top:1px solid var(--line);}
.ask:first-of-type{border-top:0;}
.ask .lab{font-family:var(--mono);font-size:11px;color:var(--faint);width:58px;flex-shrink:0;}
.ask .val{font-size:15px;font-weight:600;color:var(--ink);}
.cmp.bad .ask .val{color:var(--muted);}
.verdict{margin-top:18px;display:flex;align-items:center;gap:9px;font-size:13.5px;font-weight:600;}
.cmp.bad .verdict{color:var(--muted);}
.cmp.good .verdict{color:var(--accent2);}
.verdict .mk{width:20px;height:20px;border-radius:6px;display:flex;align-items:center;justify-content:center;font-size:12px;flex-shrink:0;}
.cmp.bad .verdict .mk{background:rgba(11,13,18,.07);color:var(--muted);}
.cmp.good .verdict .mk{background:rgba(14,157,134,.16);color:var(--accent2);}

/* ===== test transcript (page 05) ===== */
.test{border:1px solid var(--line-strong);border-radius:20px;background:var(--paper);overflow:hidden;max-width:720px;
  box-shadow:0 24px 56px -30px rgba(11,13,18,.4);}
.test .trow{display:grid;grid-template-columns:84px 1fr;gap:16px;padding:18px 22px;border-top:1px solid var(--line);align-items:baseline;}
.test .trow:first-child{border-top:0;}
.test .tw{font-family:var(--mono);font-size:11px;letter-spacing:.08em;text-transform:uppercase;color:var(--faint);}
.test .tx{font-size:15.5px;line-height:1.55;}
.test .trow.reveal{background:rgba(47,95,224,.05);}
.test .trow.reveal .tx{font-weight:700;}
.test .trow.reveal .tx b{color:var(--accent);}

/* ===== example cards (page 06) ===== */
.examples{display:grid;grid-template-columns:1fr 1fr;gap:16px;margin-top:clamp(40px,6vh,60px);}
.ex{border:1px solid var(--line);border-radius:20px;background:var(--paper2);padding:26px 24px;
  display:flex;flex-direction:column;gap:16px;transition:border-color .2s,transform .2s;}
.ex:hover{border-color:var(--line-strong);transform:translateY(-3px);}
.ex .ex-tag{display:flex;align-items:center;gap:12px;}
.ex .ex-tag .n{font-family:var(--mono);font-size:12px;color:var(--accent);}
.ex .ex-tag .ln{height:1px;flex:1;background:var(--line);}
.ex h2{font-size:clamp(21px,2.2vw,26px);font-weight:800;letter-spacing:-.025em;line-height:1.1;}
.ex .ask-bub{align-self:flex-start;display:flex;align-items:baseline;gap:9px;
  background:var(--ink);color:#fff;border-radius:13px 13px 13px 4px;padding:12px 16px;font-size:14.5px;font-weight:600;line-height:1.45;}
.ex .ask-bub .lab{font-family:var(--mono);font-size:10px;letter-spacing:.1em;text-transform:uppercase;color:#9bc0ff;flex-shrink:0;}
.ex .get{display:flex;gap:9px;align-items:baseline;font-size:14.5px;line-height:1.55;color:var(--muted);}
.ex .get .lab{font-family:var(--mono);font-size:10px;letter-spacing:.1em;text-transform:uppercase;color:var(--accent2);flex-shrink:0;}
.ex .vid{margin-top:auto;aspect-ratio:16/7;border:1px dashed var(--line-strong);border-radius:12px;background:var(--paper);
  display:flex;align-items:center;justify-content:center;gap:9px;color:var(--faint);font-family:var(--mono);font-size:11px;letter-spacing:.12em;text-transform:uppercase;}
.ex .vid .play{width:26px;height:26px;border-radius:50%;border:1px solid var(--line-strong);display:flex;align-items:center;justify-content:center;font-size:9px;color:var(--muted);}

/* ===== short version ===== */
.tldr{margin-top:clamp(72px,11vh,120px);border-radius:26px;padding:clamp(38px,5vw,64px);
  background:linear-gradient(125deg,#0b0d12,#14223c 60%,#0c3a4e);color:#fff;position:relative;overflow:hidden;}
.tldr::before{content:"";position:absolute;inset:0;pointer-events:none;
  background:radial-gradient(60% 90% at 100% 0%,rgba(47,95,224,.42),transparent 60%);}
.tldr .tk{position:relative;font-family:var(--mono);font-size:12px;letter-spacing:.24em;text-transform:uppercase;color:#39e0c4;margin-bottom:18px;}
.tldr p{position:relative;font-size:clamp(22px,2.6vw,34px);line-height:1.28;font-weight:700;letter-spacing:-.025em;text-wrap:pretty;max-width:26ch;}
.tldr b{color:#fff;}
.tldr .dim{color:rgba(255,255,255,.6);font-weight:500;}

/* ===== CTA ===== */
.cta{margin-top:24px;display:flex;flex-wrap:wrap;align-items:center;gap:16px 22px;padding:30px 4px 0;}
.cta .cl{font-size:18px;font-weight:600;color:var(--ink);margin-right:auto;letter-spacing:-.01em;}
.btn{display:inline-flex;align-items:center;gap:9px;font-size:15.5px;font-weight:600;letter-spacing:-.01em;
  padding:14px 24px;border-radius:100px;transition:transform .2s,box-shadow .2s,border-color .2s,color .2s;}
.btn .ar{transition:transform .2s;}
.btn:hover .ar{transform:translateX(4px);}
.btn-primary{background:var(--ink);color:#fff;}
.btn-primary:hover{transform:translateY(-2px);box-shadow:0 14px 34px -12px rgba(11,13,18,.55);}
.btn-ghost{border:1px solid var(--line-strong);color:var(--ink);}
.btn-ghost:hover{border-color:var(--accent);color:var(--accent);}

/* ===== prev/next pager ===== */
.pager{margin-top:clamp(56px,8vh,84px);display:grid;grid-template-columns:1fr 1fr;gap:16px;}
.pager a{border:1px solid var(--line);border-radius:16px;padding:20px 22px;display:flex;flex-direction:column;gap:7px;
  transition:border-color .2s,transform .2s;}
.pager a:hover{border-color:var(--accent);transform:translateY(-2px);}
.pager .pl{font-family:var(--mono);font-size:10.5px;letter-spacing:.14em;text-transform:uppercase;color:var(--faint);}
.pager .pq{font-size:15.5px;font-weight:700;letter-spacing:-.015em;line-height:1.3;color:var(--ink);}
.pager a.next{text-align:right;align-items:flex-end;grid-column:2;}

/* ===== floating footer ===== */
#footer{position:fixed;bottom:18px;left:7vw;z-index:50;display:flex;align-items:center;gap:18px;
  padding:8px 16px;border-radius:100px;background:rgba(255,255,255,.72);backdrop-filter:blur(14px);
  border:1px solid var(--line);box-shadow:0 8px 30px rgba(11,13,18,.1);}
#footer a{font-size:12.5px;font-weight:500;letter-spacing:.01em;color:var(--muted);transition:color .2s;}
#footer a:hover{color:var(--accent);}

@media (max-width:820px){
  .topbar{gap:0;}
  .topnav,.top-link{display:none;}
  .duo,.compare,.examples,.pager{grid-template-columns:1fr;}
  .pager a.next{grid-column:auto;}
  .tools{grid-template-columns:1fr 1fr;}
  .timeline{grid-template-columns:1fr;}
  .tstep{border-left:0;border-top:1px solid var(--line);}
  .tstep:first-child{border-top:0;}
  .test .trow{grid-template-columns:1fr;gap:6px;}
  #footer{left:6vw;bottom:14px;gap:14px;padding:7px 14px;}
}

/* ===== dropdown nav (borrowed from production header) ===== */
.nav-item{position:relative;}
.nav-trigger{display:inline-flex;align-items:center;gap:6px;background:none;border:0;padding:0;
  font:inherit;color:var(--ink);opacity:.82;cursor:pointer;transition:opacity .15s;}
.nav-item:hover .nav-trigger,.nav-item.open .nav-trigger{opacity:1;}
.nav-trigger .chev{font-style:normal;font-size:9px;opacity:.6;transition:transform .2s;}
.nav-item:hover .chev,.nav-item.open .chev{transform:rotate(180deg);}
.nav-pop{position:absolute;top:100%;left:-14px;padding-top:13px;z-index:60;
  opacity:0;visibility:hidden;transform:translateY(-6px);transition:.18s;}
.nav-item:hover .nav-pop,.nav-item.open .nav-pop,.nav-item:focus-within .nav-pop{
  opacity:1;visibility:visible;transform:none;}
.np{min-width:240px;background:#fff;border:1px solid var(--line);border-radius:14px;padding:8px;
  box-shadow:0 24px 60px -20px rgba(11,13,18,.4);}
.np a{display:block;padding:10px 13px;border-radius:9px;font-size:14px;line-height:1.3;opacity:1;
  color:var(--muted);text-decoration:none;transition:background .15s,color .15s;white-space:nowrap;}
.np a:hover{background:var(--paper2,#f6f7f9);color:var(--ink);}

/* ===== mobile menu (light pages) ===== */
.menu-btn{display:none;width:40px;height:40px;border:0;background:none;cursor:pointer;
  flex-direction:column;align-items:center;justify-content:center;gap:6px;flex-shrink:0;
  position:relative;z-index:56;-webkit-tap-highlight-color:transparent;}
.menu-btn span{display:block;width:20px;height:2px;border-radius:2px;background:var(--ink);transition:transform .25s;}
body.menu-open .menu-btn span:nth-child(1){transform:translateY(4px) rotate(45deg);}
body.menu-open .menu-btn span:nth-child(2){transform:translateY(-4px) rotate(-45deg);}
.msheet{position:fixed;inset:0;z-index:50;background:#fff;color:var(--ink);
  padding:92px 7vw 44px;overflow-y:auto;-webkit-overflow-scrolling:touch;
  opacity:0;visibility:hidden;transition:opacity .25s,visibility .25s;}
body.menu-open .msheet{opacity:1;visibility:visible;}
body.menu-open{overflow:hidden;}
body.menu-open .topbar{z-index:55;background:#fff;backdrop-filter:none;}
.msheet-grp{font-family:var(--mono);font-size:11px;letter-spacing:.22em;
  text-transform:uppercase;color:var(--accent2);margin:28px 0 6px;}
.msheet-grp:first-child{margin-top:0;}
.ms-link{display:block;padding:12px 0;font-size:17.5px;font-weight:600;letter-spacing:-.015em;
  color:var(--ink);text-decoration:none;border-bottom:1px solid rgba(11,13,18,.07);}
.msheet-actions{display:flex;gap:12px;margin-top:32px;}
.ms-btn{flex:1;text-align:center;padding:14px;border-radius:100px;font-size:15.5px;font-weight:600;text-decoration:none;}
.ms-btn.solid{background:var(--ink);color:#fff;}
.ms-btn.ghost{border:1px solid rgba(11,13,18,.3);color:var(--ink);}
@media (max-width:820px){
  .menu-btn{display:flex;}
  .msheet{padding:84px 6vw 40px;}
}

/* in-copy links */
.step p a{color:var(--accent);border-bottom:1px solid rgba(47,95,224,.35);transition:border-color .2s;}
.step p a:hover{border-bottom-color:var(--accent);}

/* ===== site footer ===== */
#sitefooter{position:relative;z-index:2;background:#fff;color:#0b0d12;
  border-top:1px solid rgba(11,13,18,.12);padding:30px 7vw 92px;}
.sf-inner{max-width:1180px;margin:0 auto;display:flex;flex-wrap:wrap;align-items:center;gap:16px 28px;}
.sf-brand{display:flex;align-items:center;gap:16px;}
.sf-brand img{height:19px;width:auto;display:block;opacity:.9;}
.sf-rights{font-size:13px;color:rgba(11,13,18,.45);}
.sf-links{margin-left:auto;display:flex;align-items:center;gap:24px;}
.sf-links a{font-size:13px;font-weight:500;color:rgba(11,13,18,.55);text-decoration:none;transition:color .2s;}
.sf-links a:hover{color:#2f5fe0;}
@media (max-width:600px){
  #sitefooter{padding:26px 6vw 96px;}
  .sf-links{margin-left:0;}
}