/* ═══════════════════════════════════════════════════════════════
   THE AI HISTORY — archival instrument aesthetic
   ink · bone · vermillion · oxide gold
   ═══════════════════════════════════════════════════════════════ */

@import url('https://fonts.googleapis.com/css2?family=Instrument+Serif:ital@0;1&family=Newsreader:ital,opsz,wght@0,6..72,200..600;1,6..72,200..500&family=JetBrains+Mono:wght@200;300;400;500&display=swap');

:root{
  --ink:        #08090b;
  --ink-2:      #0d0f13;
  --ink-3:      #14171c;
  --bone:       #ece4d3;
  --bone-2:     #b9b2a4;
  --bone-3:     #6e6a62;
  --vermillion: #ff441a;
  --vermillion-d:#c22f10;
  --gold:       #d8a13f;
  --sky:        #7ea8ce;
  --frost:      #5f7484;

  --rule:       rgba(236,228,211,.13);
  --rule-soft:  rgba(236,228,211,.07);

  --display: 'Instrument Serif', 'Times New Roman', serif;
  --body:    'Newsreader', Georgia, serif;
  --mono:    'JetBrains Mono', ui-monospace, 'SF Mono', monospace;

  --gut: clamp(1.25rem, 4vw, 5rem);
  --rail: 96px;
  --max: 1340px;
  --ease: cubic-bezier(.22,.61,.36,1);
}

*,*::before,*::after{ box-sizing:border-box; }
html{ scroll-behavior:smooth; -webkit-text-size-adjust:100%; }
@media (prefers-reduced-motion: reduce){ html{ scroll-behavior:auto; } }

body{
  margin:0; background:var(--ink); color:var(--bone);
  font-family:var(--body); font-weight:300;
  font-size:clamp(1rem,.94rem + .28vw,1.1rem); line-height:1.62;
  font-optical-sizing:auto;
  -webkit-font-smoothing:antialiased;
  overflow-x:hidden;
}
::selection{ background:var(--vermillion); color:var(--ink); }

/* ── atmosphere ────────────────────────────────────────────────── */
#gl{ position:fixed; inset:0; width:100%; height:100%; z-index:0; display:block; }
.veil{
  position:fixed; inset:0; z-index:1; pointer-events:none;
  background:
    radial-gradient(120% 80% at 50% 0%, transparent 30%, rgba(8,9,11,.55) 72%, rgba(8,9,11,.92) 100%),
    radial-gradient(60% 45% at 78% 12%, rgba(255,68,26,.055), transparent 70%);
}
.grain{
  position:fixed; inset:-120px; z-index:2; pointer-events:none; opacity:.32;
  background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='220' height='220'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.82' numOctaves='3' stitchTiles='stitch'/%3E%3CfeColorMatrix type='saturate' values='0'/%3E%3C/filter%3E%3Crect width='220' height='220' filter='url(%23n)' opacity='.55'/%3E%3C/svg%3E");
  mix-blend-mode:overlay;
  animation:grainshift 5s steps(6) infinite;
}
@keyframes grainshift{
  0%{transform:translate(0,0)} 20%{transform:translate(-12px,7px)} 40%{transform:translate(9px,-11px)}
  60%{transform:translate(-7px,-8px)} 80%{transform:translate(11px,6px)} 100%{transform:translate(0,0)}
}
@media (prefers-reduced-motion: reduce){ .grain{ animation:none; } }

main{ position:relative; z-index:3; }

/* ── instrument rails ──────────────────────────────────────────── */
.hud{
  position:fixed; z-index:20; font-family:var(--mono); font-size:.62rem;
  letter-spacing:.18em; text-transform:uppercase; color:var(--bone-3);
  pointer-events:none; mix-blend-mode:normal;
}
.hud--tl{ top:1.4rem; left:var(--gut); display:flex; gap:.9rem; align-items:baseline; }
.hud--tr{ top:1.4rem; right:var(--gut); text-align:right; display:flex; gap:.9rem; align-items:center; pointer-events:auto; }
.lang{ display:inline-flex; align-items:center; }
.lang button{
  background:none; border:0; padding:.15rem .1rem; margin:0; cursor:pointer;
  font-family:var(--mono); font-size:.62rem; letter-spacing:.18em; color:var(--bone-3);
  transition:color .25s var(--ease);
}
.lang button:hover{ color:var(--bone); }
.lang button[aria-pressed="true"]{ color:var(--vermillion); }
.lang button:focus-visible{ outline:1px solid var(--gold); outline-offset:3px; }
.lang i{ font-style:normal; opacity:.3; margin:0 .25rem; }
.hud b{ color:var(--vermillion); font-weight:400; }
.hud .era-name{ color:var(--bone); letter-spacing:.14em; }

.chrono{
  position:fixed; right:calc(var(--gut) - .2rem); top:0; bottom:0;
  z-index:20; display:flex; flex-direction:column; align-items:flex-end; justify-content:center;
  gap:.55rem; pointer-events:none;
}
.chrono::before{                            /* scrim: the rail opens over the page */
  content:''; position:fixed; right:0; top:0; bottom:0; width:30vw; max-width:370px;
  background:linear-gradient(90deg, rgba(8,9,11,0), rgba(8,9,11,.55) 45%, rgba(8,9,11,.78));
  -webkit-backdrop-filter:blur(6px); backdrop-filter:blur(6px);
  opacity:0; transition:opacity .32s var(--ease); pointer-events:none;
}
.chrono:hover::before, .chrono:focus-within::before{ opacity:1; }
.chrono__year{
  font-family:var(--mono); font-weight:200; font-size:1.55rem; letter-spacing:.02em;
  color:var(--bone); font-variant-numeric:tabular-nums; line-height:1;
  transition:color .3s var(--ease), opacity .3s var(--ease);
}
.chrono.is-probing .chrono__year{ opacity:.35; }

.chrono__bar{
  position:relative; width:1px; height:62vh; background:var(--rule);
  pointer-events:auto; cursor:crosshair;
}
.chrono__bar::before{                       /* generous hit area */
  content:''; position:absolute; left:-150px; right:-16px; top:-14px; bottom:-14px;
}
.chrono__fill{
  position:absolute; left:0; top:0; width:1px; height:0%;
  background:linear-gradient(180deg,var(--gold),var(--vermillion));
}
.chrono__marks{ position:absolute; inset:0; }

.mark{
  position:absolute; right:0; transform:translateY(-50%);
  display:flex; align-items:center; justify-content:flex-end; gap:.55rem;
  background:none; border:0; padding:.18rem 0; margin:0; cursor:pointer;
  pointer-events:auto; font:inherit; text-align:right;
}
.mark__tick{ width:7px; height:1px; background:var(--bone-3); flex:none; opacity:0;
  transition:width .3s var(--ease), background .3s var(--ease), opacity .3s var(--ease); }
.chrono:hover .mark__tick,
.chrono:focus-within .mark__tick{ opacity:1; }
.mark__label{
  opacity:0; transform:translateX(8px); transition:opacity .32s var(--ease), transform .32s var(--ease);
  font-family:var(--mono); white-space:nowrap;
  display:flex; flex-direction:row-reverse; align-items:baseline; gap:.55rem;
}
.mark__label b{ font-size:.6rem; font-weight:400; letter-spacing:.17em; text-transform:uppercase; color:var(--bone); }
html[lang="tr"] .mark__label b,
html[lang="tr"] .hud .era-name{ text-transform:none; letter-spacing:.13em; }
.mark__label i{ font-style:normal; font-size:.52rem; letter-spacing:.14em; color:var(--bone-3); font-variant-numeric:tabular-nums; }
.chrono:hover .mark__label,
.chrono:focus-within .mark__label{ opacity:1; transform:none; }
.mark:hover .mark__tick,
.mark:focus-visible .mark__tick{ width:20px; background:var(--vermillion); }
.mark:hover .mark__label b,
.mark:focus-visible .mark__label b{ color:var(--vermillion); }
.mark:focus-visible{ outline:1px solid var(--gold); outline-offset:5px; }
.chrono.is-tight .mark{ padding:.08rem 0; }
.chrono.is-tight .mark__label b{ font-size:.53rem; letter-spacing:.13em; }
.chrono.is-tight .mark__label i{ font-size:.46rem; }
.chrono.is-tight .mark__label{ gap:.4rem; }

.chrono__probe{
  position:absolute; right:0; top:0; transform:translateY(-50%);
  display:flex; align-items:center; gap:.45rem; opacity:0; pointer-events:none;
  transition:opacity .2s var(--ease);
}
.chrono.is-probing .chrono__probe{ opacity:1; }
.chrono__probe::after{ content:''; width:14px; height:1px; background:var(--gold); flex:none; order:2; }
.chrono__probe span{
  font-family:var(--mono); font-size:.78rem; font-variant-numeric:tabular-nums; color:var(--gold);
  background:var(--ink-2); border:1px solid rgba(216,161,63,.4); padding:.12rem .4rem; line-height:1.3;
}
.chrono__label{ font-family:var(--mono); font-size:.58rem; letter-spacing:.2em; color:var(--bone-3); text-align:right; }
.chrono__label b{ font-weight:400; display:block; }
.chrono__label i{
  display:block; font-style:normal; font-size:.5rem; letter-spacing:.14em; color:var(--bone-3);
  opacity:0; transition:opacity .32s var(--ease); margin-top:.4rem; max-width:14ch;
}
.chrono:hover .chrono__label i{ opacity:.85; }

@media (max-width: 900px){ .chrono{ display:none; } #hudPct{ display:none; } }

/* ── shared layout ─────────────────────────────────────────────── */
.wrap{ max-width:var(--max); margin-inline:auto; padding-inline:var(--gut); }
@media(min-width:901px){ .wrap{ padding-right:calc(var(--gut) + 62px); } }
section{ position:relative; }

.eyebrow{
  font-family:var(--mono); font-size:.63rem; letter-spacing:.32em; text-transform:uppercase;
  color:var(--bone-3); display:flex; align-items:center; gap:.8rem;
}
.eyebrow::before{ content:''; width:26px; height:1px; background:var(--vermillion); flex:none; }

h1,h2,h3,h4{ font-family:var(--display); font-weight:400; letter-spacing:-.01em; margin:0; }

/* ── hero ──────────────────────────────────────────────────────── */
.hero{ min-height:100svh; display:flex; flex-direction:column; justify-content:space-between; padding-block:clamp(5rem,12vh,9rem) 2.2rem; }
.hero__mid{ display:grid; gap:clamp(1.2rem,3vw,2rem); }
.hero__title{
  font-size:clamp(3.4rem,13.5vw,12.5rem); line-height:.82; letter-spacing:-.035em;
  margin:0; text-indent:-.04em;
}
.hero__title .the{ display:block; font-size:.24em; letter-spacing:.42em; text-indent:0;
  font-family:var(--mono); font-weight:200; color:var(--bone-2); margin-bottom:1.1rem; }
.hero__title .ai{ color:var(--vermillion); font-style:italic; margin-right:.14em; }
.hero__title em{ font-style:italic; color:var(--bone); }
.hero__sub{
  max-width:46ch; font-size:clamp(1.02rem,.95rem + .45vw,1.32rem); color:var(--bone-2);
  font-weight:200; line-height:1.55;
}
.hero__sub b{ color:var(--bone); font-weight:400; }
.hero__foot{ display:flex; flex-wrap:wrap; gap:clamp(1.4rem,5vw,4rem); align-items:flex-end; justify-content:space-between; }
.figs{ display:flex; gap:clamp(1.4rem,4vw,3.4rem); flex-wrap:wrap; }
.fig{ border-top:1px solid var(--rule); padding-top:.6rem; min-width:104px; }
.fig__n{ font-family:var(--display); font-size:clamp(1.9rem,4.4vw,3rem); line-height:1; display:block; }
.fig__n i{ font-style:italic; color:var(--gold); }
.fig__l{ font-family:var(--mono); font-size:.6rem; letter-spacing:.19em; text-transform:uppercase; color:var(--bone-3); display:block; margin-top:.5rem; }
.scrollcue{ font-family:var(--mono); font-size:.6rem; letter-spacing:.28em; text-transform:uppercase; color:var(--bone-3); display:flex; align-items:center; gap:.7rem; }
.scrollcue span{ display:block; width:44px; height:1px; background:var(--bone-3); transform-origin:left; animation:cue 2.6s var(--ease) infinite; }
@keyframes cue{ 0%,100%{transform:scaleX(.2);opacity:.4} 50%{transform:scaleX(1);opacity:1} }

/* ── prologue / quote ──────────────────────────────────────────── */
.prologue{ padding-block:clamp(7rem,16vh,13rem); }
.prologue__grid{ display:grid; grid-template-columns:minmax(0,1fr); gap:2.5rem; }
@media(min-width:900px){ .prologue__grid{ grid-template-columns:1.15fr .85fr; gap:clamp(3rem,7vw,7rem); align-items:start; } }
.quote{ font-family:var(--display); font-size:clamp(1.8rem,4.6vw,3.5rem); line-height:1.14; letter-spacing:-.02em; }
.quote em{ color:var(--gold); }
.quote__by{ font-family:var(--mono); font-size:.65rem; letter-spacing:.2em; text-transform:uppercase; color:var(--bone-3); margin-top:1.8rem; }
.prologue p{ color:var(--bone-2); }
.prologue p + p{ margin-top:1.1rem; }
.dropcap::first-letter{
  font-family:var(--display); float:left; font-size:3.9em; line-height:.78; padding:.06em .12em 0 0;
  color:var(--vermillion);
}

/* ── era header ────────────────────────────────────────────────── */
.era{ padding-block:clamp(4rem,9vh,7rem); }
.era__head{
  display:grid; gap:1.4rem; padding-bottom:clamp(2rem,5vh,3.6rem);
  border-bottom:1px solid var(--rule);
}
@media(min-width:920px){
  .era__head{ grid-template-columns:auto minmax(0,1fr) minmax(0,.8fr); gap:clamp(2rem,5vw,4.5rem); align-items:end; }
}
.era__idx{
  font-family:var(--mono); font-weight:200; font-size:clamp(2.6rem,7vw,4.6rem); line-height:.85;
  color:transparent; -webkit-text-stroke:1px var(--bone-3);
}
.era__title{ font-size:clamp(2.4rem,6.4vw,4.7rem); line-height:.95; letter-spacing:-.03em; }
.era__title i{ font-style:italic; color:var(--gold); }
.era__span{ font-family:var(--mono); font-size:.72rem; letter-spacing:.24em; color:var(--vermillion); margin-bottom:.7rem; display:block; }
.era__kicker{ color:var(--bone-2); font-style:italic; font-size:1.02rem; margin-top:.9rem; }
.era__lede{ color:var(--bone-2); font-size:1.02rem; }
.era__stat{ margin-top:1.4rem; border-left:1px solid var(--vermillion); padding-left:1rem; }
.era__stat b{ font-family:var(--display); font-weight:400; font-size:1.9rem; display:block; line-height:1; }
.era__stat i{ font-family:var(--mono); font-style:normal; font-size:.58rem; letter-spacing:.2em; text-transform:uppercase; color:var(--bone-3); display:block; margin:.45rem 0 .5rem; }
.era__stat span{ font-size:.9rem; color:var(--bone-2); }

/* winters run cold */
.era--winter .era__span{ color:var(--frost); }
.era--winter .era__title i{ color:var(--frost); }
.era--winter .era__stat{ border-left-color:var(--frost); }
.era--winter .era__head{ border-bottom-color:rgba(95,116,132,.28); }
.era--winter .era__idx{ -webkit-text-stroke-color:var(--frost); }

/* ── event spine ───────────────────────────────────────────────── */
.spine{ position:relative; padding-top:clamp(2.4rem,6vh,4rem); }
.spine::before{
  content:''; position:absolute; left:7px; top:0; bottom:0; width:1px;
  background:linear-gradient(180deg,transparent,var(--rule-soft) 8%,var(--rule-soft) 92%,transparent);
}
@media(min-width:920px){ .spine::before{ left:calc(18% + 7px); } }

.ev{ position:relative; padding:0 0 clamp(2.2rem,4.6vh,3.4rem) 2.4rem; }
@media(min-width:920px){
  .ev{ display:grid; grid-template-columns:18% minmax(0,1fr); gap:0; padding-left:0; }
  .ev__body{ padding-left:2.6rem; max-width:62ch; }
}
.ev__year{
  font-family:var(--mono); font-weight:300; font-size:.95rem; letter-spacing:.06em;
  color:var(--bone-2); font-variant-numeric:tabular-nums; display:block; margin-bottom:.5rem;
  position:relative;
}
@media(min-width:920px){ .ev__year{ text-align:left; margin-bottom:0; padding-top:.25rem; } }
.ev__dot{
  position:absolute; left:0; top:.62rem; width:15px; height:15px; border-radius:50%;
  border:1px solid var(--rule); background:var(--ink);
  display:grid; place-items:center;
}
@media(min-width:920px){ .ev__dot{ left:18%; } }
.ev__dot::after{ content:''; width:5px; height:5px; border-radius:50%; background:var(--bone-3); transition:background .4s, box-shadow .4s; }
.ev[data-tag="milestone"] .ev__dot::after{ background:var(--vermillion); }
.ev[data-tag="theory"] .ev__dot::after{ background:var(--gold); }
.ev[data-tag="system"] .ev__dot::after{ background:var(--sky); }
.ev[data-tag="winter"] .ev__dot::after{ background:var(--frost); }
.ev.is-in .ev__dot::after{ box-shadow:0 0 0 4px rgba(255,68,26,.09); }
.ev[data-w="3"] .ev__dot{ border-color:var(--bone-3); }

.ev__title{ font-size:clamp(1.28rem,2.5vw,1.85rem); line-height:1.12; letter-spacing:-.015em; }
.ev[data-w="3"] .ev__title{ font-size:clamp(1.5rem,3.2vw,2.35rem); }
.ev__who{ font-family:var(--mono); font-size:.62rem; letter-spacing:.16em; text-transform:uppercase; color:var(--bone-3); margin:.6rem 0 .85rem; display:flex; flex-wrap:wrap; gap:.7rem; align-items:center; }
.ev__tag{ border:1px solid var(--rule); padding:.15rem .45rem; border-radius:2px; font-size:.55rem; letter-spacing:.16em; }
.ev[data-tag="milestone"] .ev__tag{ color:var(--vermillion); border-color:rgba(255,68,26,.35); }
.ev[data-tag="theory"] .ev__tag{ color:var(--gold); border-color:rgba(216,161,63,.32); }
.ev[data-tag="system"] .ev__tag{ color:var(--sky); border-color:rgba(126,168,206,.3); }
.ev[data-tag="winter"] .ev__tag{ color:var(--frost); border-color:rgba(95,116,132,.35); }
.ev__text{ color:var(--bone-2); font-size:1rem; }

/* event plates */
.plate-fig{ margin:1.4rem 0 0; padding:0; max-width:340px; }
.plate-fig svg{ display:block; width:100%; height:auto; border:1px solid var(--rule-soft);
  background:rgba(13,15,19,.55); padding:.7rem; font-family:var(--mono); }
.plate-fig figcaption{ margin-top:.6rem; font-family:var(--mono); font-size:.55rem;
  letter-spacing:.17em; text-transform:uppercase; color:var(--bone-3); }
.event-art{ margin:1.4rem 0 0; max-width:300px; padding:0; }
.event-art img{ display:block; width:100%; height:auto; max-height:390px; object-fit:contain;
  border-bottom:1px solid var(--rule-soft); filter:contrast(1.04) saturate(.78); }
.event-art figcaption{ margin-top:.6rem; font-family:var(--mono); font-size:.55rem;
  letter-spacing:.17em; text-transform:uppercase; color:var(--bone-3); }
@media(min-width:1080px){
  .ev[data-w="3"] .ev__body{ display:grid; grid-template-columns:minmax(0,1fr) 300px;
    gap:clamp(1.4rem,3vw,2.6rem); align-items:start; }
  .ev[data-w="3"] .ev__title,
  .ev[data-w="3"] .ev__who,
  .ev[data-w="3"] .ev__text{ grid-column:1; }
  .ev[data-w="3"] .plate-fig{ grid-column:2; grid-row:1 / span 3; margin-top:.3rem; max-width:300px; }
  .ev[data-w="3"] .event-art{ grid-column:2; margin-top:.3rem; max-width:300px; }
  .ev[data-w="3"] .plate-fig + .event-art{ grid-row:4; margin-top:1.5rem; }
}

/* reveal */
.rv{ opacity:0; transform:translateY(22px); transition:opacity .9s var(--ease), transform .9s var(--ease); }
.rv.is-in{ opacity:1; transform:none; }
@media (prefers-reduced-motion: reduce){ .rv{ opacity:1; transform:none; transition:none; } }

/* ── data section ──────────────────────────────────────────────── */
.data{ padding-block:clamp(6rem,13vh,10rem); border-top:1px solid var(--rule); background:linear-gradient(180deg,rgba(13,15,19,.55),rgba(8,9,11,0)); }
.data__head{ max-width:64ch; margin-bottom:clamp(2.4rem,6vh,4rem); }
.data__head h2{ font-size:clamp(2.1rem,5.4vw,3.9rem); line-height:1; letter-spacing:-.03em; margin:1rem 0 1rem; }
.data__head h2 i{ font-style:italic; color:var(--vermillion); }
.data__head p{ color:var(--bone-2); }

.plate{ border:1px solid var(--rule); background:rgba(13,15,19,.5); backdrop-filter:blur(3px); padding:clamp(1.1rem,2.6vw,2rem); }
.plate + .plate{ margin-top:1.2rem; }
.plate__cap{ display:flex; justify-content:space-between; align-items:baseline; gap:1rem; flex-wrap:wrap; margin-bottom:1.4rem; }
.plate__cap h3{ font-size:1.35rem; }
.plate__cap p{ margin:.35rem 0 0; font-family:var(--mono); font-size:.6rem; letter-spacing:.16em; text-transform:uppercase; color:var(--bone-3); }
.plate svg{ display:block; width:100%; height:auto; overflow:visible; }
.scroller{ overflow-x:auto; overflow-y:hidden; scrollbar-width:thin; scrollbar-color:var(--rule) transparent; }
.scroller::-webkit-scrollbar{ height:4px; }
.scroller::-webkit-scrollbar-thumb{ background:var(--rule); }
#chartCompute svg{ min-width:700px; }
#chartModel svg{ min-width:860px; }
#chartPrice svg{ min-width:460px; }
.plate__hint{ display:none; margin:.7rem 0 0; font-family:var(--mono); font-size:.55rem;
  letter-spacing:.2em; text-transform:uppercase; color:var(--bone-3); }
@media(max-width:760px){ .plate__hint{ display:block; } }
.plate svg text{ font-family:var(--mono); fill:var(--bone-3); }

.grid2{ display:grid; gap:1.2rem; align-items:start; }
@media(min-width:960px){ .grid2{ grid-template-columns:1fr 1fr; } .grid2 .plate + .plate{ margin-top:0; } }

/* benchmark bars */
.bm{ display:grid; gap:.1rem; }
.bm__row{ display:grid; grid-template-columns:minmax(0,1fr); gap:.3rem; padding:.72rem 0; border-bottom:1px solid var(--rule-soft); }
.bm__top{ display:flex; justify-content:space-between; gap:1rem; align-items:baseline; }
.bm__name{ font-size:1rem; color:var(--bone); }
.bm__yrs{ font-family:var(--mono); font-size:.63rem; letter-spacing:.12em; color:var(--bone-3); font-variant-numeric:tabular-nums; white-space:nowrap; }
.bm__track{ position:relative; height:6px; background:var(--rule-soft); }
.bm__life{ position:absolute; height:6px; background:linear-gradient(90deg,rgba(216,161,63,.75),var(--vermillion)); transform:scaleX(0); transform-origin:left; transition:transform 1.1s var(--ease); }
.is-in .bm__life{ transform:scaleX(1); }
.bm__life.open{ background:linear-gradient(90deg,rgba(126,168,206,.6),rgba(126,168,206,.08)); }
.bm__note{ font-size:.86rem; color:var(--bone-3); }

/* ── the silicon ───────────────────────────────────────────────── */
.train, .nv{ display:grid; gap:clamp(1.4rem,3vw,2.6rem); }
@media(min-width:920px){
  .train{ grid-template-columns:1.15fr .85fr; align-items:center; }
  .nv{ grid-template-columns:1.05fr .95fr; align-items:start; }
}
.train__viz svg, .nv__viz svg{ display:block; width:100%; height:auto; font-family:var(--mono); }
#siNvViz svg{ min-width:420px; }
.train__side{ display:flex; flex-direction:column; gap:1.2rem; }
.train__side p{ margin:0; color:var(--bone-2); font-size:.96rem; }
.train__side .figs{ gap:clamp(1rem,3vw,2.2rem); }
.train__side .fig__n{ font-size:clamp(1.5rem,3.4vw,2.2rem); }

.nv__lede{ margin:0 0 1.4rem; color:var(--bone-2); font-size:1rem; }
.beats{ list-style:none; margin:0; padding:0; display:grid; gap:.9rem; }
.beats li{ display:grid; grid-template-columns:3.4rem minmax(0,1fr); gap:.9rem;
  padding-top:.9rem; border-top:1px solid var(--rule-soft); }
.beats b{ font-family:var(--mono); font-size:.68rem; font-weight:400; letter-spacing:.12em;
  color:var(--vermillion); padding-top:.18rem; font-variant-numeric:tabular-nums; }
.beats h4{ font-family:var(--display); font-weight:400; font-size:1.12rem; line-height:1.1; margin:0 0 .3rem; }
.beats p{ margin:0; font-size:.9rem; color:var(--bone-2); }

.rivals{ display:grid; gap:1px; background:var(--rule); border:1px solid var(--rule); margin-top:1.4rem; }
@media(min-width:680px){ .rivals{ grid-template-columns:1fr 1fr; } }
@media(min-width:1060px){ .rivals{ grid-template-columns:repeat(3,1fr); } }
.rival{ background:var(--ink); padding:clamp(1.1rem,2.2vw,1.6rem); display:flex; flex-direction:column; gap:.55rem;
  transition:background .45s var(--ease); }
.rival:hover{ background:var(--ink-2); }
.rival h4{ font-family:var(--display); font-weight:400; font-size:1.3rem; line-height:1; margin:0; }
.rival span{ font-family:var(--mono); font-size:.56rem; letter-spacing:.18em; text-transform:uppercase; color:var(--sky); }
.rival p{ margin:0; font-size:.9rem; color:var(--bone-2); }

.moat{ margin-top:1.4rem; border-left:1px solid var(--vermillion); padding:.2rem 0 .2rem 1.2rem; max-width:74ch; }
.moat h4{ font-family:var(--display); font-weight:400; font-size:clamp(1.3rem,2.6vw,1.7rem); line-height:1.05; margin:0 0 .5rem; }
.moat p{ margin:0; color:var(--bone-2); font-size:.98rem; }

/* model-scale notes */
.notes{ display:grid; gap:clamp(1.3rem,3vw,2.6rem); margin-top:clamp(1.8rem,4vh,2.8rem); }
@media(min-width:860px){ .notes{ grid-template-columns:repeat(3,1fr); } }
.note{ border-top:1px solid var(--rule); padding-top:1rem; }
.note b{ display:block; font-family:var(--display); font-weight:400; font-size:1.28rem;
  line-height:1.08; letter-spacing:-.01em; margin-bottom:.65rem; text-wrap:balance; }
.note p{ margin:0; font-size:.94rem; color:var(--bone-2); }
.plate .legend{ margin-top:1.2rem; padding-top:1rem; border-top:1px solid var(--rule-soft); }

/* ── how it works ──────────────────────────────────────────────── */
.how-sec{ padding-block:clamp(6rem,13vh,10rem); border-top:1px solid var(--rule);
  background:linear-gradient(180deg,rgba(13,15,19,.5),rgba(8,9,11,0)); }
.how{ display:grid; gap:clamp(1.4rem,3vw,2.4rem); margin-top:clamp(2rem,5vh,3.4rem); }
@media(min-width:960px){
  .how{ grid-template-columns:1.42fr .58fr; grid-template-areas:'stage side' 'rail rail'; align-items:start; }
  .how__stage{ grid-area:stage; } .how__side{ grid-area:side; } .how__rail{ grid-area:rail; }
}
#howMount:focus-visible{ outline:1px solid var(--gold); outline-offset:8px; }

.how__stage{ border:1px solid var(--rule); background:rgba(13,15,19,.55); }
.how__stage svg{ display:block; width:100%; height:auto; font-family:var(--mono); }
.how__stage svg text{ letter-spacing:.02em; }

.how__side{ display:flex; flex-direction:column; gap:.7rem; }
.how__n{ font-family:var(--mono); font-weight:200; font-size:clamp(2.2rem,5vw,3.4rem); line-height:.85;
  color:transparent; -webkit-text-stroke:1px var(--bone-3); }
.how__t{ font-family:var(--display); font-size:clamp(1.4rem,3vw,1.95rem); line-height:1.05; letter-spacing:-.015em; }
.how__b{ margin:0; color:var(--bone-2); font-size:.96rem; }

.how__rail{ display:flex; align-items:center; gap:clamp(1rem,3vw,2rem); flex-wrap:wrap;
  border-top:1px solid var(--rule); padding-top:1rem; }
.how__play{ background:none; border:1px solid var(--rule); color:var(--bone-2); cursor:pointer;
  font-family:var(--mono); font-size:.58rem; letter-spacing:.2em; text-transform:uppercase;
  padding:.45rem .9rem; border-radius:2px; transition:color .25s var(--ease), border-color .25s var(--ease); }
.how__play:hover{ color:var(--bone); border-color:var(--bone-3); }
.how__play:focus-visible{ outline:1px solid var(--gold); outline-offset:3px; }
.how__steps{ display:flex; gap:clamp(.6rem,2vw,1.4rem); }
.how__step{ background:none; border:0; margin:0; padding:.3rem 0; cursor:pointer;
  display:flex; flex-direction:column; align-items:center; gap:.45rem; }
.how__step i{ display:block; width:clamp(22px,4vw,42px); height:2px; background:var(--rule); transition:background .3s var(--ease); }
.how__step span{ font-family:var(--mono); font-size:.55rem; letter-spacing:.16em; color:var(--bone-3); transition:color .3s var(--ease); }
.how__step:hover i{ background:var(--bone-3); }
.how__step[aria-current="true"] i{ background:var(--vermillion); }
.how__step[aria-current="true"] span{ color:var(--bone); }
.how__step:focus-visible{ outline:1px solid var(--gold); outline-offset:3px; }

/* stage motion */
.how__stage .tk{ opacity:0; transform:translateY(9px); }
.how__stage .grow{ opacity:0; }
.how__stage .arc,
.how__stage .draw{ stroke-dasharray:1; stroke-dashoffset:1; }
.how__stage .is-live .tk{ animation:hkIn .55s var(--ease) forwards; animation-delay:var(--d,0ms); }
.how__stage .is-live .grow{ animation:hkFade .6s var(--ease) forwards; animation-delay:var(--d,140ms); }
.how__stage .is-live .arc,
.how__stage .is-live .draw{ animation:hkDraw .95s var(--ease) forwards; animation-delay:var(--d,120ms); }
.how__stage .pulse{ animation:hkPulse 2.4s ease-in-out infinite; }
@keyframes hkIn{ to{ opacity:1; transform:none; } }
@keyframes hkFade{ to{ opacity:1; } }
@keyframes hkDraw{ to{ stroke-dashoffset:0; } }
@keyframes hkPulse{ 0%,100%{ opacity:1; } 50%{ opacity:.25; } }
@media (prefers-reduced-motion: reduce){
  .how__stage .tk,.how__stage .grow{ opacity:1; transform:none; animation:none; }
  .how__stage .arc,.how__stage .draw{ stroke-dashoffset:0; animation:none; }
  .how__stage .pulse{ animation:none; }
}

/* ── now section ───────────────────────────────────────────────── */
.now{ padding-block:clamp(6rem,13vh,10rem); border-top:1px solid var(--rule); }
.panels{ display:grid; gap:1px; background:var(--rule); border:1px solid var(--rule); margin-top:clamp(2rem,5vh,3.4rem); }
@media(min-width:720px){ .panels{ grid-template-columns:1fr 1fr; } }
@media(min-width:1120px){
  .panels{ grid-template-columns:repeat(4,1fr); }
  /* ten cards in a four-column grid: the closing pair widens so the row fills */
  .panels .panel:nth-child(9), .panels .panel:nth-child(10){ grid-column:span 2; }
}
.panel{ background:var(--ink); padding:clamp(1.3rem,2.4vw,1.9rem); display:flex; flex-direction:column; gap:.7rem; transition:background .5s var(--ease); }
.panel:hover{ background:var(--ink-2); }
.panel__k{ font-family:var(--mono); font-size:.58rem; letter-spacing:.22em; text-transform:uppercase; color:var(--vermillion); }
.panel h3{ font-size:1.42rem; line-height:1.06; letter-spacing:-.015em; }
.panel p{ margin:0; font-size:.94rem; color:var(--bone-2); }

/* ── questions ─────────────────────────────────────────────────── */
.qs{ padding-block:clamp(6rem,13vh,10rem); border-top:1px solid var(--rule); }
.q{ display:grid; grid-template-columns:auto minmax(0,1fr); gap:1.4rem; align-items:baseline;
  padding:clamp(1.1rem,2.6vh,1.8rem) 0; border-bottom:1px solid var(--rule-soft); }
.q__n{ font-family:var(--mono); font-size:.62rem; color:var(--bone-3); letter-spacing:.16em; }
.q__t{ font-family:var(--display); font-size:clamp(1.35rem,3.6vw,2.5rem); line-height:1.12; letter-spacing:-.02em; color:var(--bone); transition:color .4s; }
.q:hover .q__t{ color:var(--gold); }

/* ── colophon ──────────────────────────────────────────────────── */
.colophon{ padding-block:clamp(4rem,9vh,7rem) 3rem; border-top:1px solid var(--rule); background:var(--ink-2); }
.colophon__grid{ display:grid; gap:2.4rem; }
@media(min-width:840px){ .colophon__grid{ grid-template-columns:1.1fr 1fr; gap:clamp(2rem,6vw,6rem); } }
.src{ display:grid; grid-template-columns:auto minmax(0,1fr); gap:.7rem 1.4rem; font-size:.88rem; color:var(--bone-2); }
.src dt{ font-family:var(--mono); font-size:.6rem; letter-spacing:.14em; text-transform:uppercase; color:var(--bone); padding-top:.28rem; white-space:nowrap; }
.src dd{ margin:0; }
.colophon h2{ font-size:clamp(1.7rem,4vw,2.6rem); line-height:1.02; letter-spacing:-.025em; margin-bottom:1rem; }
.colophon p{ color:var(--bone-2); font-size:.94rem; }
.connect{ margin-top:clamp(2.6rem,6vh,4rem); padding-top:1.6rem; border-top:1px solid var(--rule);
  display:flex; align-items:center; gap:clamp(1rem,3vw,2.4rem); flex-wrap:wrap; }
.connect__k{ margin:0; font-family:var(--mono); font-size:.6rem; letter-spacing:.24em;
  text-transform:uppercase; color:var(--bone-3); }
.connect__links{ display:flex; gap:.7rem; flex-wrap:wrap; }
.connect__link{
  display:inline-flex; align-items:center; gap:.6rem; text-decoration:none;
  border:1px solid var(--rule); border-radius:2px; padding:.55rem .95rem;
  font-family:var(--mono); font-size:.62rem; letter-spacing:.16em; text-transform:uppercase;
  color:var(--bone-2); background:rgba(13,15,19,.5);
  transition:color .3s var(--ease), border-color .3s var(--ease), background .3s var(--ease);
}
.connect__link svg{ width:13px; height:13px; flex:none; }
/* a handle is an identifier, not a label — never re-case it */
.connect__link--x span{ text-transform:none; letter-spacing:.08em; font-size:.68rem; }
.connect__link i{ font-style:normal; opacity:.45; transition:transform .3s var(--ease); }
.connect__link:hover{ color:var(--bone); background:var(--ink-2); }
.connect__link:hover i{ transform:translate(2px,-2px); }
.connect__link--coffee:hover{ border-color:rgba(216,161,63,.55); background:rgba(216,161,63,.07); }
.connect__link--coffee:hover svg{ color:var(--gold); }
.connect__link--x:hover{ border-color:rgba(236,228,211,.35); background:rgba(236,228,211,.05); }
.connect__link:focus-visible{ outline:1px solid var(--gold); outline-offset:3px; }

.fineprint{ margin-top:2.6rem; padding-top:1.4rem; border-top:1px solid var(--rule);
  font-family:var(--mono); font-size:.58rem; letter-spacing:.16em; text-transform:uppercase; color:var(--bone-3);
  display:flex; justify-content:space-between; gap:1rem; flex-wrap:wrap; }

/* ── legend ────────────────────────────────────────────────────── */
.legend{ display:flex; gap:1.2rem; flex-wrap:wrap; font-family:var(--mono); font-size:.58rem;
  letter-spacing:.18em; text-transform:uppercase; color:var(--bone-3); margin-top:1.6rem; }
.legend i{ width:7px; height:7px; border-radius:50%; display:inline-block; margin-right:.45rem; vertical-align:middle; }