/* Case-study pages (projects/glossary/ first). Builds on p2029.css.
   Motion is decoration on top of real text: every visual has a text
   equivalent on the page, and prefers-reduced-motion gets a still version.
   Chapter visuals only animate while on screen (.in, set by case-study.js). */

.cs{
  --ink:#171715; --soft:#5a594f; --mute:#8a897f; --line:rgba(23,23,21,.1);
  --sage:#6b8a6b; --sage-d:#3f6b48; --tint:#dce6d6; --tint-2:#eaf0e7;
  --amber:#b06a24; --amber-bg:#f5e4cf;
  --card:rgba(255,255,255,.72);
}
/* each case study keeps the structure and swaps the accent: ink for the semantic layer, sand for the writing agents */
.cs.t-ink{--sage:#5d7196;--sage-d:#33466e;--tint:#dfe4ee;--tint-2:#eceff5}
.cs.t-sand{--sage:#a5814f;--sage-d:#6e5130;--tint:#efe5d5;--tint-2:#f6efe3}
.cs-depth-note{font-size:14.5px;line-height:1.6;color:var(--mute);font-weight:300;max-width:42em}

.cs-main{padding-bottom:40px}

/* ============================== hero ============================== */
.cs-hero{
  display:grid;grid-template-columns:minmax(0,1.05fr) minmax(0,1fr);gap:56px;align-items:center;
  min-height:calc(100vh - 90px);padding:40px 0 72px;
}
.cs-hero .back-link{display:inline-block;margin-bottom:28px}
.cs-meta,.cs-num{
  margin:0 0 18px;font-family:"JetBrains Mono",monospace;font-size:12px;letter-spacing:.02em;color:var(--sage-d);
}
.cs-hero h1{
  margin:0 0 22px;font-size:clamp(38px,4.8vw,62px);line-height:1.03;font-weight:400;letter-spacing:-.035em;color:var(--ink);
  text-wrap:balance;
}
.cs-lede{margin:0 0 28px;max-width:30em;font-size:19px;line-height:1.55;color:var(--soft);font-weight:300}
.cs-proof{list-style:none;margin:0 0 34px;padding:0;display:grid;gap:10px}
.cs-proof li{display:flex;align-items:baseline;gap:10px;font-size:15px;line-height:1.45;color:var(--soft);font-weight:300}
.cs-proof li::before{content:"";flex:0 0 7px;height:7px;border-radius:50%;background:var(--sage);transform:translateY(-1px)}
.cs-proof b{font-weight:500;color:var(--ink)}
.cs-actions{display:flex;gap:10px;flex-wrap:wrap}

.cs-btn{
  display:inline-flex;align-items:center;gap:10px;font:inherit;font-size:14px;line-height:1;cursor:pointer;
  padding:14px 22px;border-radius:999px;border:1px solid var(--ink);background:var(--ink);color:#f6f5f1;
  transition:background .2s,border-color .2s,transform .2s;
}
.cs-btn:hover{background:#2a2a26;transform:translateY(-1px)}
.cs-btn.ghost{background:transparent;color:var(--ink);border-color:rgba(23,23,21,.22)}
.cs-btn.ghost:hover{border-color:rgba(23,23,21,.45);background:rgba(255,255,255,.5)}
.cs-btn .voice-dot{background:var(--sage-d);box-shadow:none}
.cs-btn:focus-visible,.cs-next-card:focus-visible,.cs-depth summary:focus-visible,.gc input:focus-visible{outline:2px solid var(--sage);outline-offset:3px}
.cs-play{width:0;height:0;border-left:9px solid currentColor;border-top:6px solid transparent;border-bottom:6px solid transparent}
.cs-dur{font-family:"JetBrains Mono",monospace;font-size:11px;opacity:.6}

/* ============================== the flow (hero + ch 7) ============================== */
.cs-flow{
  position:relative;margin:0;height:340px;border-radius:24px;background:var(--tint);overflow:hidden;
  box-shadow:inset 0 0 0 1px rgba(23,23,21,.05);
}
.cs-flow figcaption,.cs-vis figcaption{
  position:absolute;left:20px;bottom:14px;margin:0;font-family:"JetBrains Mono",monospace;font-size:11px;color:rgba(23,23,21,.5);
}
.fl-node{
  position:absolute;top:58%;transform:translate(-50%,-50%);z-index:2;
  display:flex;flex-direction:column;align-items:center;gap:4px;text-align:center;
  padding:14px 16px;min-width:116px;border-radius:16px;background:#fbfaf6;box-shadow:0 1px 0 rgba(23,23,21,.06),0 10px 30px -12px rgba(23,23,21,.25);
}
.fl-node span{font-size:15px;font-weight:500;letter-spacing:-.01em;color:var(--ink)}
.fl-node small{font-family:"JetBrains Mono",monospace;font-size:10px;color:var(--mute)}
.fl-agent{left:17%}
.fl-gloss{left:50%;background:var(--ink);border-radius:999px;padding:18px 22px}
.fl-gloss span{color:#f6f5f1}
.fl-gloss small{color:#a9c2a9}
.fl-screen{left:83%}
.fl-track{position:absolute;top:58%;left:17%;right:17%;border-top:1.5px dashed rgba(63,107,72,.35);z-index:1}

.fl-token{
  position:absolute;top:28%;left:17%;transform:translateX(-50%);z-index:3;white-space:nowrap;
  padding:8px 12px;border-radius:10px;font-family:"JetBrains Mono",monospace;font-size:12px;opacity:0;
}
.fl-wrong{background:var(--amber-bg);color:var(--amber);box-shadow:inset 0 0 0 1px rgba(176,106,36,.3)}
.fl-info{background:#fbfaf6;color:var(--ink);box-shadow:inset 0 0 0 1px rgba(63,107,72,.35)}
.fl-info b{color:var(--sage-d);font-weight:500}
.fl-right{background:var(--sage-d);color:#f6f5f1}

.cs-flow:not(.busy) .fl-wrong{animation:fl-wrong 9s ease-in-out infinite}
.cs-flow:not(.busy) .fl-info{animation:fl-info 9s ease-in-out infinite}
.cs-flow:not(.busy) .fl-right{animation:fl-right 9s ease-in-out infinite}
.cs-flow:not(.busy) .fl-gloss{animation:fl-pulse 9s ease-in-out infinite}
.cs-flow:not(.busy) .fl-screen{animation:fl-land 9s ease-in-out infinite}

@keyframes fl-wrong{
  0%{left:17%;opacity:0} 5%{opacity:1} 28%{left:50%;opacity:1} 36%{left:50%;opacity:1} 40%{left:50%;opacity:0} 100%{left:50%;opacity:0}
}
@keyframes fl-info{
  0%,37%{left:50%;opacity:0} 42%{left:50%;opacity:1} 58%{left:17%;opacity:1} 63%,100%{left:17%;opacity:0}
}
@keyframes fl-right{
  0%,60%{left:17%;opacity:0} 65%{left:17%;opacity:1} 86%{left:83%;opacity:1} 95%{left:83%;opacity:1} 100%{left:83%;opacity:0}
}
@keyframes fl-pulse{
  0%,26%,46%,100%{box-shadow:0 1px 0 rgba(23,23,21,.06),0 10px 30px -12px rgba(23,23,21,.25),0 0 0 0 rgba(107,138,107,0)}
  34%{box-shadow:0 1px 0 rgba(23,23,21,.06),0 10px 30px -12px rgba(23,23,21,.25),0 0 0 14px rgba(107,138,107,.22)}
}
@keyframes fl-land{
  0%,84%,100%{box-shadow:0 1px 0 rgba(23,23,21,.06),0 10px 30px -12px rgba(23,23,21,.25)}
  90%{box-shadow:0 1px 0 rgba(23,23,21,.06),0 10px 30px -12px rgba(23,23,21,.25),0 0 0 10px rgba(107,138,107,.25)}
}

/* busy: a steady stream, for "it became how products get built" */
.fl-dot{position:absolute;top:58%;left:17%;z-index:1;width:12px;height:12px;margin:-6px 0 0 -6px;border-radius:50%;background:var(--sage-d);opacity:0}
.cs-flow.busy .fl-dot{animation:fl-stream 4.8s linear infinite}
.cs-flow.busy .d2{animation-delay:-1.2s}
.cs-flow.busy .d3{animation-delay:-2.4s}
.cs-flow.busy .d4{animation-delay:-3.6s}
.cs-flow.busy .fl-gloss{animation:fl-pulse-soft 1.2s ease-in-out infinite}
@keyframes fl-stream{0%{left:17%;opacity:0} 8%{opacity:1} 92%{opacity:1} 100%{left:83%;opacity:0}}
@keyframes fl-pulse-soft{50%{box-shadow:0 1px 0 rgba(23,23,21,.06),0 10px 30px -12px rgba(23,23,21,.25),0 0 0 9px rgba(107,138,107,.18)}}

/* ============================== chapters ============================== */
.cs-ch{
  display:grid;grid-template-columns:minmax(0,.9fr) minmax(0,1.1fr);gap:64px;align-items:center;
  padding:96px 0;border-top:1px solid var(--line);scroll-margin-top:80px;
}
.cs-ch h2{
  margin:0 0 18px;font-size:clamp(28px,3.2vw,42px);line-height:1.08;font-weight:400;letter-spacing:-.03em;color:var(--ink);text-wrap:balance;
}
.cs-ch-text p:not(.cs-num){margin:0;max-width:32em;font-size:17px;line-height:1.65;color:var(--soft);font-weight:300}
.cs-ch-text{transition:opacity .7s ease,transform .7s ease}
.js .cs-ch:not(.in) .cs-ch-text{opacity:0;transform:translateY(14px)}

.cs-quote{margin:28px 0 0;padding:4px 0 4px 20px;border-left:2px solid var(--sage)}
.cs-quote p{margin:0 !important;font-size:20px !important;line-height:1.45 !important;color:var(--ink) !important;font-weight:300}

.cs-vis{position:relative;margin:0;height:320px;border-radius:24px;background:var(--tint-2);overflow:hidden;box-shadow:inset 0 0 0 1px rgba(23,23,21,.05)}
.cs-vis:not(.in) *,.cs-flow.busy:not(.in) *{animation-play-state:paused !important}

.cs-wide{grid-template-columns:1fr;gap:36px}
.cs-wide .cs-ch-text{max-width:760px}

/* ---- ch 1–2: lanes ---- */
.ln-end{
  position:absolute;top:50%;transform:translateY(-50%);z-index:2;padding:10px 14px;border-radius:12px;background:#fbfaf6;
  font-size:13px;font-weight:500;color:var(--ink);box-shadow:0 8px 24px -14px rgba(23,23,21,.3);
}
.ln-from{left:4%}
.ln-to{right:4%}
.ln-line{position:absolute;top:50%;left:20%;right:16%;border-top:1.5px solid rgba(63,107,72,.35)}
.ln-gate{
  position:absolute;top:50%;z-index:2;width:42px;height:42px;margin:-21px 0 0 -21px;border-radius:50%;
  background:#fbfaf6;box-shadow:inset 0 0 0 2px var(--sage);transition:opacity .5s,filter .5s;
}
.ln-gate span{
  position:absolute;top:52px;left:50%;transform:translateX(-50%);white-space:nowrap;
  font-family:"JetBrains Mono",monospace;font-size:10px;color:var(--soft);
}
.g1{left:36%} .g2{left:50%} .g3{left:64%}
.ln-chip{
  position:absolute;top:50%;left:20%;z-index:1;width:26px;height:12px;margin:-6px 0 0 -13px;border-radius:5px;
  background:var(--sage-d);font-style:normal;animation:ln-move 7.5s linear infinite;
}
.c2{animation-delay:-2.5s} .c3{animation-delay:-5s}
@keyframes ln-move{0%{left:20%;opacity:0} 6%{opacity:1} 94%{opacity:1} 100%{left:84%;opacity:0}}

.bypass .ln-line{opacity:.35}
.bypass .ln-gate{opacity:.35;filter:grayscale(1)}
.ln-fast{
  position:absolute;top:24%;left:20%;right:16%;height:26%;z-index:0;
  border:1.5px dashed rgba(176,106,36,.55);border-bottom:0;border-radius:18px 18px 0 0;
}
.ln-chip.fast{
  top:24%;width:auto;height:auto;margin:-11px 0 0 0;padding:4px 8px;border-radius:7px;transform:translateX(-50%);
  background:var(--amber-bg);color:var(--amber);box-shadow:inset 0 0 0 1px rgba(176,106,36,.3);
  font-family:"JetBrains Mono",monospace;font-size:11px;white-space:nowrap;animation:ln-fast 3.6s linear infinite;
}
.f2{animation-delay:-1.2s !important} .f3{animation-delay:-2.4s !important}
@keyframes ln-fast{0%{left:22%;opacity:0} 8%{opacity:1} 90%{opacity:1} 100%{left:82%;opacity:0}}

/* ---- ch 3: timeline ---- */
.timeline{display:flex;align-items:center;padding:0 28px}
.timeline ol{
  position:relative;list-style:none;margin:0;padding:0;width:100%;
  display:grid;grid-template-columns:repeat(6,1fr);gap:6px;
}
.timeline ol::before,.timeline ol::after{content:"";position:absolute;top:9px;left:8%;right:8%;height:2px;background:rgba(23,23,21,.1)}
.timeline ol::after{background:var(--sage);transform-origin:left;transform:scaleX(0);transition:transform 2.4s cubic-bezier(.5,0,.2,1) .2s}
.timeline.in ol::after{transform:scaleX(1)}
.timeline li{position:relative;z-index:1;display:flex;flex-direction:column;align-items:center;gap:10px;text-align:center}
.timeline li::before{
  content:"";width:20px;height:20px;border-radius:50%;background:#fbfaf6;box-shadow:inset 0 0 0 2px rgba(23,23,21,.18);
  transition:box-shadow .4s,background .4s;transition-delay:calc(var(--i,0) * .4s + .3s);
}
.timeline.in li::before{background:var(--sage);box-shadow:inset 0 0 0 2px var(--sage)}
.timeline span{font-size:12.5px;line-height:1.3;color:var(--soft)}
.timeline b{
  font-family:"JetBrains Mono",monospace;font-size:11px;font-weight:400;color:#f6f5f1;background:var(--sage-d);
  padding:3px 8px;border-radius:999px;opacity:0;transform:translateY(4px);transition:opacity .4s,transform .4s;transition-delay:calc(var(--i,0) * .4s + .5s);
}
.timeline.in b{opacity:1;transform:none}
.tl-key span{color:var(--ink);font-weight:500}

/* ---- ch 4: the glossary check ---- */
.gc{
  padding:28px;border-radius:24px;background:var(--card);box-shadow:inset 0 0 0 1px var(--line),0 30px 60px -40px rgba(23,23,21,.35);
}
.gc-form label{display:block;margin:0 0 10px;font-size:14px;color:var(--soft)}
.gc-row{display:flex;gap:10px}
.gc-row input{
  flex:1 1 auto;min-width:0;font:inherit;font-size:16px;padding:14px 18px;border-radius:14px;
  border:1px solid rgba(23,23,21,.16);background:#fff;color:var(--ink);
}
.gc-try{display:flex;flex-wrap:wrap;align-items:center;gap:6px;margin-top:10px;font-size:13px;color:var(--mute)}
.gc-try span{margin-right:2px}
.gc-try button{font:inherit;font-size:12.5px;line-height:1.35;text-align:left;padding:5px 11px;border-radius:14px;border:1px solid var(--line);background:#fbfaf6;color:var(--soft);cursor:pointer;transition:border-color .2s,color .2s}
.gc-try button:hover{border-color:rgba(23,23,21,.35);color:var(--ink)}
.gc-try button:focus-visible{outline:2px solid var(--sage);outline-offset:2px}
.gc-sentence{margin:22px 0 0;min-height:1.6em;font-size:19px;line-height:1.6;color:var(--ink);font-weight:300}
.gc-sentence mark{border-radius:4px;padding:1px 3px;background:var(--amber-bg);color:var(--amber)}
.gc-sentence mark.ok{background:var(--tint);color:var(--sage-d)}

.gc-steps{list-style:none;margin:20px 0 0;padding:0;display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px}
.gc-step[data-step="respond"]{grid-column:1 / -1}
.gc-step[data-step="respond"] .gc-out{display:grid;grid-template-columns:repeat(auto-fit,minmax(230px,1fr));gap:10px}
.gc-step{
  display:flex;flex-direction:column;min-width:0;padding:16px;border-radius:16px;background:#fbfaf6;box-shadow:inset 0 0 0 1px var(--line);
  opacity:.45;transition:opacity .4s,box-shadow .4s;
}
.gc-step.on{opacity:1;box-shadow:inset 0 0 0 1px rgba(63,107,72,.35)}
.gc-step h3{margin:0;display:flex;align-items:center;gap:8px;font-size:15px;font-weight:500;color:var(--ink)}
.gc-count{margin-left:auto;font-family:"JetBrains Mono",monospace;font-size:11px;font-weight:400;color:var(--sage-d)}
.gc-step h3 b{
  display:inline-grid;place-items:center;width:20px;height:20px;border-radius:50%;
  font-family:"JetBrains Mono",monospace;font-size:11px;font-weight:400;background:var(--ink);color:#f6f5f1;
}
.gc-step > p{margin:4px 0 12px;font-size:12.5px;line-height:1.4;color:var(--mute)}
.gc-out{display:flex;flex-wrap:wrap;gap:5px;align-content:flex-start;min-height:52px}
.gc-chip{
  display:inline-block;padding:3px 7px;border-radius:6px;font-family:"JetBrains Mono",monospace;font-size:11px;line-height:1.4;
  background:rgba(23,23,21,.05);color:var(--soft);opacity:0;transform:translateY(3px);animation:gc-pop .3s ease forwards;
}
.gc-chip.form{background:var(--tint-2);color:var(--sage-d)}
.gc-chip.hit{background:var(--amber-bg);color:var(--amber)}
.gc-chip.hit.ok{background:var(--tint);color:var(--sage-d)}
.gc-more{font-family:"JetBrains Mono",monospace;font-size:11px;color:var(--mute);align-self:center}
@keyframes gc-pop{to{opacity:1;transform:none}}
.gc-res{
  width:100%;padding:10px 12px;border-radius:10px;background:#fff;box-shadow:inset 0 0 0 1px var(--line);
  font-size:12.5px;line-height:1.5;color:var(--soft);opacity:0;transform:translateY(4px);animation:gc-pop .35s ease forwards;
}
.gc-res.bad{box-shadow:inset 3px 0 0 var(--amber),inset 0 0 0 1px var(--line)}
.gc-res.good{box-shadow:inset 3px 0 0 var(--sage),inset 0 0 0 1px var(--line)}
.gc-res b{color:var(--ink);font-weight:500}
.gc-res .k{font-family:"JetBrains Mono",monospace;font-size:10.5px;color:var(--mute)}
.gc-res .bad{color:var(--amber)}
.gc-res .good{color:var(--sage-d)}
.gc-none{margin:0;font-size:12.5px;color:var(--mute)}
.gc-agent{margin-top:16px;padding:16px 18px;border-radius:16px;background:var(--ink);color:#f6f5f1;animation:gc-pop .4s ease forwards}
.gc-agent-label{margin:0 0 4px;font-family:"JetBrains Mono",monospace;font-size:11px;color:#a9c2a9}
.gc-agent-line{margin:0;font-size:18px;line-height:1.5;font-weight:300}
.gc-agent-line ins{text-decoration:none;color:#c7dcc4;border-bottom:1px solid rgba(199,220,196,.5)}
.gc-fine{margin:14px 0 0;font-family:"JetBrains Mono",monospace;font-size:11px;color:var(--mute)}

/* ---- ch 5: approval ---- */
.approve{display:grid;grid-template-columns:auto auto 1fr;align-items:center;gap:22px;padding:0 28px}
.ap-card,.ap-stamp{
  display:flex;flex-direction:column;gap:4px;padding:16px 18px;border-radius:16px;background:#fbfaf6;
  box-shadow:0 10px 30px -16px rgba(23,23,21,.3);transition:opacity .6s,transform .6s;
}
.ap-card small,.ap-stamp small{font-family:"JetBrains Mono",monospace;font-size:10px;color:var(--mute)}
.ap-card b{font-size:17px;font-weight:500;color:var(--ink)}
.ap-stamp{background:var(--sage-d);transition-delay:.7s}
.ap-stamp span{font-size:15px;font-weight:500;color:#f6f5f1}
.ap-stamp small{color:#c7dcc4}
.ap-langs{list-style:none;margin:0;padding:0;display:flex;flex-wrap:wrap;gap:6px}
.ap-langs li{
  padding:5px 8px;border-radius:7px;background:#fbfaf6;font-family:"JetBrains Mono",monospace;font-size:11px;color:var(--sage-d);
  box-shadow:inset 0 0 0 1px rgba(63,107,72,.25);transition:opacity .35s,transform .35s;transition-delay:calc(1.3s + var(--i,0) * .05s);
}
.js .approve:not(.in) .ap-card{opacity:0;transform:translateX(-12px)}
.js .approve:not(.in) .ap-stamp{opacity:0;transform:scale(.92)}
.js .approve:not(.in) .ap-langs li{opacity:0;transform:translateY(5px)}

/* ---- ch 6: rollout grid ---- */
.grid{display:flex;align-items:center;justify-content:center;padding:28px 28px 44px}
.grid ul{list-style:none;margin:0;padding:0;width:100%;max-width:420px;display:grid;grid-template-columns:repeat(6,1fr);gap:8px}
.grid li{
  aspect-ratio:1;border-radius:9px;background:rgba(23,23,21,.06);
  transition:background .4s;transition-delay:calc(var(--i,0) * .08s);
}
.grid.in li{background:var(--sage)}
.grid.in li.cf{background:#d99a55;animation:gc-fix .5s ease forwards;animation-delay:calc(2.4s + var(--i,0) * .06s)}
@keyframes gc-fix{to{background:var(--sage)}}
.grid figcaption{display:flex;align-items:center;gap:6px}
.dot{display:inline-block;width:8px;height:8px;border-radius:50%;margin-left:6px}
.dot.ok{background:var(--sage);margin-left:0}
.dot.cf{background:#d99a55}

/* ---- ch 8: next ---- */
.cs-next-card{
  display:flex;flex-direction:column;gap:6px;padding:0 0 22px;border-radius:24px;overflow:hidden;text-decoration:none;
  background:#1b2230;color:#f6f5f1;transition:transform .25s;
}
.cs-next-card:hover{transform:translateY(-3px)}
.cs-next-card img{width:100%;height:auto;margin-bottom:12px}
.cs-next-card span{padding:0 22px;font-family:"JetBrains Mono",monospace;font-size:11px;color:#9cc39c}
.cs-next-card b{padding:0 22px;font-size:20px;font-weight:400;letter-spacing:-.015em}

/* ============================== depth ============================== */
.cs-depth{padding:72px 0 40px;border-top:1px solid var(--line);max-width:820px}
.cs-depth-title{margin:0 0 20px;font-family:"JetBrains Mono",monospace;font-size:12px;font-weight:400;color:var(--sage-d)}
.cs-depth details{border-bottom:1px solid var(--line)}
.cs-depth summary{
  display:flex;align-items:center;gap:12px;padding:18px 0;cursor:pointer;list-style:none;
  font-size:18px;color:var(--ink);letter-spacing:-.01em;
}
.cs-depth summary::-webkit-details-marker{display:none}
.cs-depth summary::before{content:"+";width:16px;font-family:"JetBrains Mono",monospace;color:var(--sage-d)}
.cs-depth details[open] summary::before{content:"−"}
.cs-depth details > :not(summary){margin:0 0 22px 28px}
.cs-depth li,.cs-depth dd{font-size:15.5px;line-height:1.65;color:var(--soft);font-weight:300}
.cs-depth ol,.cs-depth ul:not(.tags){padding-left:18px;display:grid;gap:6px}
.cs-depth li::marker{color:var(--sage)}
.cs-depth dt{margin-top:12px;font-size:15.5px;color:var(--ink)}
.cs-depth dd{margin:2px 0 0}
.cs-arch{display:flex;flex-wrap:wrap;align-items:center;gap:8px;margin-top:6px !important}
.cs-arch span{padding:7px 11px;border-radius:9px;background:var(--tint-2);font-family:"JetBrains Mono",monospace;font-size:11.5px;color:var(--sage-d)}
.cs-arch i{width:14px;border-top:1.5px solid var(--sage)}

/* ============================== the presenter ============================== */
/* The rail: always on, the walkthrough's controls and a map of the chapters.
   Its fill follows the narration while it plays, and the scroll otherwise. */
.cs .voice-launch{display:none}
.rail{
  position:fixed;left:22px;top:96px;bottom:110px;z-index:60;width:40px;
  display:flex;flex-direction:column;align-items:center;gap:8px;
}
.rail > button{position:relative;display:grid;place-items:center;flex:0 0 auto;border-radius:50%;cursor:pointer}
.rail-play{width:40px;height:40px;background:var(--ink);margin-top:4px}
.rail-play::before,.rail-play::after{content:"";position:absolute;top:14px;width:3.5px;height:12px;border-radius:1px;background:#f6f5f1;display:none}
.rail-play::before{left:14px} .rail-play::after{left:22px}
.rail.playing .rail-play::before,.rail.playing .rail-play::after{display:block}
.rail:not(.playing) .rail-play::before{
  display:block;left:16px;top:13px;width:0;height:0;border-radius:0;background:none;
  border-left:10px solid #f6f5f1;border-top:7px solid transparent;border-bottom:7px solid transparent;
}
.rail-step{width:28px;height:28px;color:var(--mute);background:transparent;transition:color .2s,background .2s}
.rail-step:hover{color:var(--ink);background:rgba(23,23,21,.06)}

.rail-track{position:relative;flex:1 1 auto;width:20px;margin:4px 0}
.rail-track::before,.rail-fill{content:"";position:absolute;left:50%;top:0;width:2px;margin-left:-1px;border-radius:2px}
.rail-track::before{bottom:0;background:rgba(23,23,21,.12)}
.rail-fill{height:calc(var(--p,0) * 100%);background:var(--sage);transition:height .2s linear}
.rail-stop{
  position:absolute;left:50%;top:calc(var(--at) * 100%);width:20px;height:20px;margin:-10px 0 0 -10px;
  display:grid;place-items:center;border-radius:50%;cursor:pointer;
}
.rail-stop::before{
  content:"";width:9px;height:9px;border-radius:50%;background:#f6f5f1;box-shadow:inset 0 0 0 1.5px rgba(23,23,21,.3);
  transition:transform .2s,background .2s,box-shadow .2s;
}
.rail-stop.past::before{background:var(--sage);box-shadow:inset 0 0 0 1.5px var(--sage)}
.rail-stop.now::before{background:var(--sage-d);box-shadow:0 0 0 4px rgba(107,138,107,.22);transform:scale(1.2)}
.rail-stop:hover::before{transform:scale(1.35)}
.rail-time{font-family:"JetBrains Mono",monospace;font-size:10px;color:var(--mute);letter-spacing:.02em}

/* labels sit to the right of the rail: on hover, and for the current chapter while playing */
.rail-label{
  position:absolute;left:calc(100% + 12px);top:50%;transform:translate(-4px,-50%);white-space:nowrap;pointer-events:none;
  padding:5px 9px;border-radius:8px;background:rgba(23,23,21,.88);color:#f6f5f1;
  font-family:"JetBrains Mono",monospace;font-size:11px;font-weight:400;line-height:1.2;
  opacity:0;transition:opacity .2s,transform .2s;
}
.rail button:hover > .rail-label,.rail button:focus-visible > .rail-label{opacity:1;transform:translate(0,-50%)}
/* with room in the margin, the current chapter stays named while playing */
@media (min-width:1560px){
  .rail.active .rail-stop.now > .rail-label{opacity:1;transform:translate(0,-50%);background:transparent;color:var(--sage-d);padding-left:0}
  .rail.active .rail-stop.now:hover > .rail-label{background:rgba(23,23,21,.88);color:#f6f5f1;padding-left:9px}
}
.rail button:focus-visible{outline:2px solid var(--sage);outline-offset:2px}

/* room for the rail beside the content */
@media (max-width:1330px) and (min-width:761px){ .cs-main{padding-left:88px} }

/* subtitles: bottom center, like a film */
.subs{
  position:fixed;left:50%;bottom:28px;z-index:59;transform:translateX(-50%);
  width:min(760px,calc(100vw - 180px));text-align:center;pointer-events:none;
}
.subs[hidden]{display:none}
.subs-line{margin:0;font-size:19px;line-height:1.5;font-weight:400}
.subs-line:not(:empty){
  display:inline;padding:4px 10px;border-radius:6px;background:rgba(23,23,21,.84);color:rgba(246,245,241,.5);
  -webkit-box-decoration-break:clone;box-decoration-break:clone;
}
.subs-line span{transition:color .25s}
.subs-line span.said{color:#f6f5f1}
.subs-line[hidden]{display:none}
.subs-end{
  display:inline-flex;flex-wrap:wrap;justify-content:center;align-items:center;gap:8px;pointer-events:auto;
  padding:10px 12px 10px 18px;border-radius:999px;background:rgba(23,23,21,.88);color:#f6f5f1;
}
.subs-end[hidden]{display:none}
.subs-end p{margin:0 6px 0 0;font-size:16px;font-weight:300}
.subs-chip{
  display:inline-block;padding:7px 13px;border-radius:999px;border:1px solid rgba(246,245,241,.25);background:none;
  font:inherit;font-size:13px;color:#f6f5f1;text-decoration:none;cursor:pointer;
}
.subs-chip:hover{border-color:rgba(246,245,241,.6)}
.subs-chip.on{background:#f6f5f1;color:#171715;border-color:#f6f5f1}
.subs-chip:focus-visible{outline:2px solid #9cc39c;outline-offset:2px}

.cs-ch.wt-current .cs-ch-text h2{color:var(--sage-d)}
/* while narrating, the chapter being talked about is the only one at full strength */
.cs-hero,.cs-ch,.cs-depth{transition:opacity .6s ease}
.wt-on .cs-hero,.wt-on .cs-ch:not(.wt-current),.wt-on .cs-depth{opacity:.25}
.cs-main{padding-bottom:40vh}

/* phones: the rail lies down as a slim row along the bottom, subtitles above it */
@media (max-width:760px){
  .rail{
    top:auto;left:10px;right:10px;bottom:10px;width:auto;height:48px;flex-direction:row;gap:6px;padding:4px 10px 4px 4px;
    border-radius:999px;background:rgba(246,245,241,.94);box-shadow:0 10px 30px -12px rgba(23,23,21,.35),inset 0 0 0 1px var(--line);
    backdrop-filter:blur(14px);-webkit-backdrop-filter:blur(14px);
  }
  .rail-play{margin:0}
  .rail-step svg{transform:rotate(-90deg)}
  .rail-track{width:auto;height:20px;margin:0 4px}
  .rail-track::before,.rail-fill{left:0;top:50%;width:auto;height:2px;margin:-1px 0 0}
  .rail-track::before{right:0}
  .rail-fill{width:calc(var(--p,0) * 100%);transition:width .2s linear}
  .rail-stop{left:calc(var(--at) * 100%);top:50%;margin:-10px 0 0 -10px}
  .rail-label{display:none}
  .subs{bottom:72px;width:calc(100vw - 28px)}
  .subs-line{font-size:15.5px}
}
/* ============================== responsive ============================== */
@media (max-width:960px){
  .cs-hero{grid-template-columns:1fr;min-height:0;gap:36px;padding:24px 0 56px}
  .cs-ch{grid-template-columns:1fr;gap:28px;padding:64px 0}
  .gc-steps{grid-template-columns:1fr 1fr 1fr}
  .approve{grid-template-columns:1fr;justify-items:start;padding:24px}
  .cs-vis.approve{height:auto}
}
@media (max-width:600px){
  .cs-flow{height:280px}
  .fl-node{min-width:0;padding:10px 10px}
  .fl-node span{font-size:13px}
  .fl-node small{display:none}
  .fl-agent{left:16%} .fl-screen{left:84%}
  .fl-token{font-size:11px;padding:6px 9px}
  .cs-vis{height:260px}
  .ln-end{font-size:11px;padding:8px 9px}
  .ln-gate span{font-size:9px}
  .timeline{padding:24px 20px;height:auto}
  .timeline ol{grid-template-columns:1fr;gap:16px}
  .timeline ol::before,.timeline ol::after{top:10px;bottom:10px;left:9px;right:auto;width:2px;height:auto}
  .timeline ol::after{transform-origin:top;transform:scaleY(0)}
  .timeline.in ol::after{transform:scaleY(1)}
  .timeline li{flex-direction:row;text-align:left;gap:12px}
  .gc{padding:18px}
  .gc-row{flex-direction:column}
  .gc-steps{grid-template-columns:1fr}
}

@media (prefers-reduced-motion: reduce){
  .cs *,.cs *::before,.cs *::after{animation-duration:.01ms !important;animation-iteration-count:1 !important;transition-duration:.01ms !important;transition-delay:0s !important}
  /* show the flow's end state instead of animating it */
  .cs-flow:not(.busy) .fl-right{opacity:1;left:83%}
  .cs-flow:not(.busy) .fl-wrong{opacity:1;left:17%}
  .js .cs-ch:not(.in) .cs-ch-text{opacity:1;transform:none}
}

/* the flow sizes itself to its own panel, wherever the panel lands */
.cs-flow{container-type:inline-size}
@container (max-width:470px){
  .fl-node{min-width:0;padding:10px 12px;border-radius:13px}
  .fl-node span{font-size:13.5px}
  .fl-node small{display:none}
  .fl-gloss{padding:13px 16px}
  .fl-agent{left:15%} .fl-screen{left:85%}
  .fl-track{left:15%;right:15%}
  .fl-token{font-size:11px;padding:6px 9px}
}
@container (max-width:340px){
  .fl-node span{font-size:12px}
  .fl-node{padding:8px 9px}
  .fl-gloss{padding:11px 12px}
}
.fl-node{max-width:27%;min-width:96px}
.fl-node small{line-height:1.35;max-width:112px}
.fl-gloss{max-width:none}
.grid ul{max-width:400px;grid-template-columns:repeat(8,1fr);gap:7px}
.grid li{border-radius:7px}
.cs-proof li{display:block;position:relative;padding-left:17px}
.cs-proof li::before{position:absolute;left:0;top:.6em;transform:none;width:7px;height:7px}