/* RLPulse — WORLD CLASS pass. Display type, cinematic dark, warm paper light, real chart craft. */
@import url("https://fonts.googleapis.com/css2?family=Fraunces:ital,opsz,wght@0,9..144,500;0,9..144,700;1,9..144,500;1,9..144,700&family=Inter:wght@400;500;600;700;800&family=JetBrains+Mono:wght@400;500;700&display=swap");
:root{
  --bg:#070a12; --bg2:#0b0f1d; --panel:#101728; --panel2:#16203a; --inset:#080c16;
  --ink:#f5f0e1; --muted:#b7ad94; --faint:#847b64;
  --line:#232c49; --line2:#35436e;
  --pro:#ffb020; --prohot:#ffcf6e; --prodeep:#8a4d00;
  --flash:#46d4ff; --flashdeep:#0b5f8f;
  --lime:#c4f542; --lime-ink:#141b06;
  --good:#7ee2a8; --bad:#ff7d7d; --amber:#ffd166;
  --accent:#ff9e2c;
  --serif:"Fraunces",Georgia,"Times New Roman",serif;
  --sans:"Inter",-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,sans-serif;
  --mono:"JetBrains Mono",ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
  --r:1.1rem;
  --shadow:0 1.25rem 3.5rem rgba(0,0,0,.5);
}
html[data-theme="light"]{
  --bg:#f4f1e7; --bg2:#ece8d9; --panel:#fffdf6; --panel2:#ffffff; --inset:#eee9d8;
  --ink:#191712; --muted:#57503f; --faint:#847a64;
  --line:#ddd5ba; --line2:#c6bb99;
  --pro:#c26a00; --flash:#006f9e; --lime:#4a7a00; --lime-ink:#f4ffd6;
  --good:#0d6b3c; --bad:#b42323; --amber:#8a5a00;
  --accent:#e07f00;
  --shadow:0 1rem 2.5rem rgba(60,50,20,.14);
}
html[data-theme="light"] .takeaways b,
html[data-theme="light"] .chapcard .sc,html[data-theme="light"] .kicker,
html[data-theme="light"] .simread b,html[data-theme="light"] .scorering,
html[data-theme="light"] .drawer h4{color:#3d6400}
html[data-theme="light"] .t-live{color:#3d6400}
html[data-theme="light"] .t-live i{background:#3d6400;box-shadow:0 0 .6rem rgba(61,100,0,.5)}
html[data-theme="light"] button.term{background:rgba(74,122,0,.1);border-bottom-color:var(--lime)}
html[data-theme="light"] button.term:hover{color:var(--lime)}
html[data-theme="light"] .quizopt.right{background:rgba(13,107,60,.1)}
html[data-theme="light"] .tile.pass{background:rgba(13,107,60,.1)}
html{scroll-behavior:smooth;scroll-padding-top:9.5rem}
@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}*{animation-duration:.01ms!important;transition-duration:.01ms!important}}
*,*::before,*::after{box-sizing:border-box}
body{
  margin:0;color:var(--ink);background:var(--bg);
  font-family:var(--serif);
  font-size:clamp(1.0625rem,1rem + .35vw,1.25rem);
  line-height:1.75;-webkit-font-smoothing:antialiased;overflow-x:hidden;
}
body::before{
  content:"";position:fixed;inset:0;pointer-events:none;z-index:0;
  background-image:linear-gradient(rgba(140,160,220,.06) 1px,transparent 1px),linear-gradient(90deg,rgba(140,160,220,.06) 1px,transparent 1px);
  background-size:2.75rem 2.75rem;
  mask-image:radial-gradient(75rem 43.75rem at 50% 0%,#000 25%,transparent 85%);
  -webkit-mask-image:radial-gradient(75rem 43.75rem at 50% 0%,#000 25%,transparent 85%);
}
/* breathing room: consistent vertical rhythm, airier sections */
main>*+*,.chapter>*+*,.chapbody>*+*,.lab>*+*{margin-top:clamp(1rem,2.4vw,1.6rem)}
main>*{margin-top:0}
/* pacing: air between sections, clear chapter rhythm */
section.wrap{padding-top:clamp(3.5rem,8vw,6rem);padding-bottom:clamp(1.5rem,3vw,2.5rem)}
section.wrap + section.wrap{border-top:1px solid var(--line)}
#map{padding-top:clamp(4rem,9vw,7rem)}
#curious,#how{padding-top:clamp(3rem,7vw,5rem)}
.chapter{padding:clamp(1.8rem,4.5vw,3.4rem);margin-bottom:clamp(2rem,4vw,3rem)}
.chapter .chapbody>*+*{margin-top:1.2em}
/* chapter cards: lift, glow keyline, room to breathe */
.chapgrid{gap:clamp(1.2rem,2.6vw,1.8rem)}
.chapcard{transition:transform .25s ease,border-color .25s ease,box-shadow .25s ease}
.chapcard:hover{transform:translateY(-4px);border-color:var(--pro);box-shadow:0 1rem 2.5rem rgba(255,176,32,.12),var(--shadow)}
.chapcard .go{color:var(--pro)}
.curgrid,.labgrid,.telegrid,.timeline{gap:clamp(1rem,2.4vw,1.6rem)}
.lab{padding:clamp(1.4rem,3vw,2.2rem)}
.panel{padding:1.4rem clamp(1.2rem,2.5vw,1.8rem);margin:1.6rem 0}
.examline{padding:1.3rem clamp(1.2rem,2.5vw,1.8rem);margin-top:2rem}
.takeaways{padding:1.2rem clamp(1.2rem,2.5vw,1.7rem)}
.chapgrid,.labgrid,.telegrid,.timeline{gap:clamp(1rem,2.4vw,1.6rem)}
.chartcard{padding:1.4rem clamp(1.2rem,2.5vw,1.8rem) 1.6rem}
.verdicts{gap:.8rem}
.controls{gap:.8rem}
.sechead{margin-bottom:.6rem}
.secsub{margin-top:.6rem;margin-bottom:1.2rem}
h1,h2,h3,h4,.sans{font-family:var(--sans)}
h1{font-family:var(--serif);font-weight:700;letter-spacing:-.02em;text-wrap:balance;
  font-size:clamp(2.1rem,1.3rem + 4.2vw,3.9rem);line-height:1.06;margin:.2em 0 .5em}
h1 em{font-style:italic;color:var(--pro)}
h2{font-size:clamp(1.4rem,1.1rem + 1.8vw,2.2rem);line-height:1.18;letter-spacing:-.015em;text-wrap:balance;margin:0}
h3{font-size:clamp(1.05rem,.95rem + .6vw,1.25rem)}
p{margin:.8em 0}
::selection{background:var(--pro);color:#1a1000}
a{color:var(--flash)}
:focus{outline:none}
:focus-visible{outline:.15rem dashed var(--lime);outline-offset:.2rem;border-radius:.4rem}
button{font:inherit}
.mono{font-family:var(--mono);font-size:.86em}
.small{font-size:.9em;color:var(--muted)}
.skip{position:absolute;left:-999px;top:0;background:var(--lime);color:var(--lime-ink);padding:.6rem 1rem;z-index:200;font-family:var(--sans);font-weight:700;border-radius:0 0 .5rem 0}
.skip:focus{left:0}

/* telemetry strip */
.telemetry{position:relative;z-index:2;display:flex;align-items:center;gap:1rem;overflow-x:auto;
  padding:.55rem clamp(.9rem,3vw,1.8rem);font-family:var(--mono);font-size:.78rem;white-space:nowrap;
  background:var(--bg2);border-bottom:1px solid var(--line);scrollbar-width:none}
.telemetry::-webkit-scrollbar{display:none}
.t-live{color:var(--lime);display:flex;align-items:center;gap:.45rem}
.t-live i{width:.5rem;height:.5rem;border-radius:50%;background:var(--lime);box-shadow:0 0 .6rem var(--lime);flex:none}
.t-src{color:var(--faint)}
.t-costs{margin-left:auto;display:flex;gap:.9rem}
.t-costs .pro{color:var(--pro)} .t-costs .flash{color:var(--flash)} .t-costs .total{color:var(--amber)}

/* header: single row on desktop, stacked rows on phone */
.topbar{position:sticky;top:0;z-index:90;display:flex;align-items:center;gap:.8rem;
  padding:.7rem clamp(.9rem,3vw,1.8rem);background:var(--bg);border-bottom:1px solid var(--line)}
.brand{display:flex;align-items:center;gap:.65rem;text-decoration:none;color:var(--ink);min-height:2.75rem;min-width:0;flex:none}
.logo{width:2.4rem;height:2.4rem;flex:none;border-radius:50%;display:flex;align-items:center;justify-content:center;
  font-family:var(--sans);font-weight:800;font-size:.95rem;color:#1a1000;
  background:radial-gradient(circle at 35% 30%,#ffd58a,var(--pro) 60%,#c66a00);box-shadow:0 0 1.2rem rgba(255,176,32,.45)}
.bname{font-family:var(--sans);font-weight:800;font-size:1.02rem;line-height:1.2;overflow:hidden;text-overflow:ellipsis}
.bname em{display:inline-block;font-style:normal;font-weight:600;font-size:.68rem;color:var(--pro);
  border:1px solid var(--line2);border-radius:999px;padding:.1rem .55rem;margin-left:.5rem;vertical-align:.15rem;white-space:nowrap}
.bsub{display:block;font-size:.72rem;color:var(--muted);font-weight:400;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.headctl{display:flex;align-items:center;gap:.5rem;margin-left:auto;min-width:0}
.headctl .sitenav{flex:1 1 auto;min-width:0}
/* chapter-local depth toggle shares the pill look */
.chmodetoggle .seg{flex:1;border:0;background:transparent;color:var(--muted);border-radius:999px;
  padding:.55rem .8rem;cursor:pointer;font-family:var(--sans);font-weight:650;font-size:.85rem;min-height:2.75rem;
  white-space:nowrap;text-align:center;min-width:0}
.chmodetoggle .seg.on{background:var(--accent);color:#1c1000;box-shadow:0 .2rem 1rem rgba(255,158,44,.4)}
.themebox{position:relative;flex:none}
.themebtn{background:var(--panel2);border:1px solid var(--line2);color:var(--ink);border-radius:.7rem;
  padding:.5rem .7rem;cursor:pointer;font-family:var(--sans);font-size:.8rem;min-height:2.6rem;white-space:nowrap}
.thememenu{position:absolute;right:0;top:calc(100% + .4rem);background:var(--panel2);border:1px solid var(--line2);
  border-radius:.8rem;padding:.35rem;min-width:11rem;box-shadow:var(--shadow);z-index:95}
.thememenu[hidden]{display:none}
.thememenu button{display:block;width:100%;text-align:left;background:none;border:0;color:var(--ink);
  padding:.6rem .8rem;border-radius:.5rem;cursor:pointer;min-height:2.75rem;font-size:.88rem}
.thememenu button:hover{background:var(--panel)}

/* tabs */
.tabs{position:sticky;top:0;z-index:80;display:flex;gap:.5rem;overflow-x:auto;
  padding:.6rem clamp(.9rem,3vw,1.8rem);background:var(--bg);
  border-bottom:1px solid var(--line);scrollbar-width:none}
.tabs.stuck{box-shadow:0 .6rem 1.6rem rgba(0,0,0,.35)}
.tabs::-webkit-scrollbar{display:none}
.tabs a{flex:none;display:flex;align-items:center;gap:.5rem;text-decoration:none;color:var(--muted);
  font-family:var(--sans);font-size:.86rem;font-weight:600;border:1px solid transparent;border-radius:.7rem;
  padding:.6rem .95rem;min-height:2.75rem}
.tabs a.on{color:var(--pro);border-bottom:.15rem solid var(--pro);border-radius:.7rem .7rem 0 0}
.tabs .pill{font-family:var(--mono);font-size:.66rem;background:var(--panel2);border:1px solid var(--line2);
  border-radius:999px;padding:.12rem .55rem;color:var(--muted);white-space:nowrap}

/* wide fluid canvas: full-bleed on laptop, capped + bigger on 4K */
.wrap{position:relative;z-index:1;width:100%;max-width:110rem;margin:0 auto;
  padding-left:clamp(1rem,4vw,3rem);padding-right:clamp(1rem,4vw,3rem)}
main{padding-bottom:4rem}

/* hero: the visual idea — a "30-step wall" of glowing progress cells behind the copy */
.hero{position:relative;display:grid;grid-template-columns:1fr;gap:clamp(1.6rem,4vw,3.5rem);
  padding-top:clamp(2.5rem,6vw,5rem);padding-bottom:clamp(2rem,4vw,3rem);overflow:clip}
.hero-wall{position:absolute;inset:0;pointer-events:none;opacity:.5;
  background-image:radial-gradient(circle at 50% 50%,rgba(255,176,32,.14) 0 2px,transparent 3px);
  background-size:26px 26px;
  mask-image:linear-gradient(180deg,#000 0%,transparent 75%);
  -webkit-mask-image:linear-gradient(180deg,#000 0%,transparent 75%)}
.hero-copy{position:relative}
.hero .stepcount{font-family:var(--mono);font-size:.72rem;letter-spacing:.24em;color:var(--pro);text-transform:uppercase}
.hero .scrollcue{margin-top:2rem;display:flex;align-items:center;gap:.7rem;color:var(--faint);
  font-family:var(--mono);font-size:.72rem;letter-spacing:.18em;text-transform:uppercase}
.hero .scrollcue::after{content:"";width:2.5rem;height:1px;background:var(--line2);animation:cue 2.2s ease-in-out infinite}
@keyframes cue{0%,100%{opacity:.4;transform:translateX(0)}50%{opacity:1;transform:translateX(8px)}}
/* animated counters */
.count{font-variant-numeric:tabular-nums}
/* scroll reveal */
.rv{opacity:0;transform:translateY(22px);transition:opacity .7s ease,transform .7s cubic-bezier(.2,.7,.2,1)}
.rv.in{opacity:1;transform:none}
@media (prefers-reduced-motion:reduce){.rv{opacity:1;transform:none;transition:none}.hero .scrollcue::after{animation:none}}
.kicker{font-family:var(--mono);font-size:.74rem;letter-spacing:.2em;text-transform:uppercase;color:var(--lime);
  margin:0 0 .8rem;display:flex;align-items:center;gap:.6rem}
.kicker::after{content:"";height:1px;width:4rem;background:var(--line2)}
.lede{font-size:clamp(1.25rem,1.05rem + 1.2vw,1.65rem);line-height:1.55;max-width:46rem}
.lede strong{color:var(--pro)}
.chapter .ch-sub{color:var(--ink);font-family:var(--serif);font-size:clamp(1.1rem,1rem + .7vw,1.35rem);max-width:62rem;line-height:1.6}
.chapbody{font-size:clamp(1.05rem,1rem + .45vw,1.22rem);line-height:1.78}
.chapter{background:var(--panel);border:1px solid var(--line);border-radius:1.4rem;
  padding:clamp(1.6rem,4vw,3.2rem);margin:0 0 1.6rem;box-shadow:var(--shadow);scroll-margin-top:12rem;min-width:0;
  container-type:inline-size;container-name:chapter}
.chapter .examline,.chapter .lab,.chapter .panel,.chapter .takeaways,.chapter .tech{max-width:100%}
.chapbody{max-width:68ch}
.chapbody .lab{margin-left:calc(-1 * clamp(0rem,2vw,1rem));margin-right:calc(-1 * clamp(0rem,2vw,1rem))}
.secsub{color:var(--muted);font-family:var(--sans);font-size:clamp(1.05rem,1rem + .5vw,1.25rem);max-width:60rem;line-height:1.6}
.sechead{font-size:clamp(1.5rem,1.2rem + 1.8vw,2.4rem)}
.sechead h2{font-size:1em}
.sechead .ico{color:var(--pro);font-size:1em}
.cta-row{display:flex;flex-wrap:wrap;gap:.7rem;margin:1.4rem 0}
a.cta{font-family:var(--sans);font-weight:700;font-size:.95rem;color:#1c1000;background:var(--accent);
  border-radius:999px;padding:.85rem 1.7rem;text-decoration:none;min-height:3rem;display:inline-flex;align-items:center;
  box-shadow:0 .4rem 1.6rem rgba(255,158,44,.35)}
a.cta:hover{filter:brightness(1.07)}
a.cta.ghost{background:transparent;color:var(--ink);border:1px solid var(--line2);box-shadow:none}
.facts{display:grid;grid-template-columns:repeat(2,1fr);gap:.6rem;margin:1.2rem 0 0;padding:0}
.facts div{background:var(--panel);border:1px solid var(--line);border-radius:.9rem;padding:.7rem .9rem}
.facts dt{font-family:var(--mono);font-size:.64rem;letter-spacing:.13em;text-transform:uppercase;color:var(--faint)}
.facts dd{margin:.15rem 0 0;font-family:var(--mono);font-size:.98rem}
.hero-side{min-width:0}
.runcards{display:grid;grid-template-columns:1fr;gap:1rem}
.runcard{position:relative;overflow:hidden;background:linear-gradient(180deg,var(--panel2),var(--panel));
  border:1px solid var(--line2);border-radius:1.1rem;padding:1.2rem 1.3rem;box-shadow:var(--shadow)}
.runcard::before{content:"";position:absolute;top:0;left:0;right:0;height:.2rem}
.runcard.pro::before{background:linear-gradient(90deg,var(--pro),#ffd58a,var(--pro))}
.runcard.flash::before{background:linear-gradient(90deg,#0e6ea8,var(--flash),#0e6ea8)}
.runcard.pro{color:var(--pro)} .runcard.flash{color:var(--flash)}
.runcard .model{font-family:var(--mono);font-size:.66rem;letter-spacing:.14em;text-transform:uppercase;color:var(--muted)}
.runcard h3{margin:.2rem 0;color:var(--ink);font-size:1.25rem}
.runcard .step{font-family:var(--mono);font-size:.72rem;color:var(--faint)}
.runcard .big{font-family:var(--mono);font-size:clamp(1.7rem,1.4rem + 1.4vw,2.2rem);color:var(--ink)}
.runcard .big small{font-size:.72rem;color:var(--muted)}
.runcard svg.spark{width:100%;height:3.2rem;display:block;margin-top:.4rem}
.statgrid{display:grid;grid-template-columns:repeat(4,1fr);gap:.5rem;margin-top:.7rem;padding-top:.7rem;border-top:1px dashed var(--line2)}
.statgrid div{font-family:var(--mono);font-size:.66rem;color:var(--faint);text-transform:uppercase;letter-spacing:.05em;min-width:0}
.statgrid b{display:block;color:var(--ink);font-size:.9rem;overflow-wrap:anywhere}
.sidenote{font-size:.84rem;color:var(--faint);font-family:var(--sans)}

/* sections */
section.wrap{padding-top:clamp(2rem,5vw,3.5rem)}
.sechead{display:flex;align-items:center;gap:1rem;flex-wrap:wrap;margin-bottom:.3rem;font-size:clamp(1.5rem,1.2rem + 1.8vw,2.4rem)}
.sechead h2{font-size:1em}
.sechead .ico{color:var(--pro);font-size:1em}
.tpill{margin-left:auto;font-family:var(--mono);font-size:.72rem;color:var(--muted);
  border:1px solid var(--line2);border-radius:999px;padding:.25rem .8rem;white-space:nowrap}
.secsub{color:var(--muted);font-family:var(--sans);font-size:clamp(1.05rem,1rem + .5vw,1.25rem);max-width:60rem;line-height:1.6}
.morelink{margin-left:auto;font-family:var(--sans);font-weight:700;color:var(--pro);font-size:.9rem;white-space:nowrap}

/* chapter cards */
.chapgrid{display:grid;grid-template-columns:1fr;gap:.9rem;margin:1.4rem 0 2rem}
.chapcard{background:linear-gradient(180deg,var(--panel2),var(--panel));border:1px solid var(--line);
  border-radius:1rem;padding:1.1rem 1.15rem;display:flex;flex-direction:column;gap:.4rem;min-height:12rem;min-width:0}
.chapcard:hover{border-color:var(--line2)}
.chapcard .cnum{font-family:var(--mono);color:var(--pro);font-size:.85rem}
.chapcard .cmin{font-family:var(--mono);font-size:.66rem;color:var(--faint);border:1px solid var(--line2);
  border-radius:999px;padding:.1rem .55rem;margin-left:.5rem;white-space:nowrap}
.chapcard h3{margin:.2rem 0;font-size:1.02rem;line-height:1.35}
.chapcard p{font-size:.88rem;color:var(--muted);font-family:var(--sans);margin:0}
.chapcard .go{margin-top:auto;display:flex;align-items:center;justify-content:space-between;color:var(--pro);
  font-family:var(--sans);font-weight:700;font-size:.86rem;background:none;border:0;cursor:pointer;
  padding:.6rem 0;min-height:2.75rem;text-align:left}
.chapcard .sc{font-family:var(--mono);font-size:.68rem;color:var(--lime)}

/* chapter articles */
.chapter{background:var(--panel);border:1px solid var(--line);border-radius:1.4rem;
  padding:clamp(1.6rem,4vw,3.2rem);margin:0 0 1.6rem;box-shadow:var(--shadow);scroll-margin-top:12rem;min-width:0;
  container-type:inline-size;container-name:chapter}
.chapter .ch-head{display:flex;align-items:baseline;gap:.8rem;flex-wrap:wrap;border-bottom:1px solid var(--line);
  padding-bottom:.9rem;margin-bottom:1rem}
.chapter .ch-head .n{font-family:var(--mono);color:var(--pro);font-size:.9rem}
.chapter .ch-head h3{margin:0;font-size:clamp(1.4rem,1.15rem + 1.6vw,2.2rem);letter-spacing:-.01em}
.chapter .ch-head .mins{margin-left:auto;font-family:var(--mono);font-size:.7rem;color:var(--faint);white-space:nowrap}
.tech{display:none;background:var(--inset);border:1px dashed var(--line2);border-radius:.8rem;
  padding:.8rem 1rem;font-family:var(--sans);font-size:.95rem;color:var(--muted)}
html[data-mode="engineer"] .tech{display:block}
.takeaways{background:rgba(185,241,75,.05);border:1px solid var(--line);border-radius:.9rem;
  padding:1rem 1.2rem;font-family:var(--sans);font-size:clamp(.98rem,.95rem + .3vw,1.08rem)}
.takeaways b{color:var(--lime)}

/* exam launcher */
.examline{display:flex;align-items:center;gap:1rem;flex-wrap:wrap;background:var(--inset);
  border:1px solid var(--line2);border-radius:1rem;padding:1rem 1.2rem;margin-top:1.4rem}
.examline .et{font-family:var(--sans);font-weight:700}
.examline .es{font-family:var(--mono);font-size:.74rem;color:var(--muted)}
.examline .btn{margin-left:auto}

/* panels */
.panel{background:var(--panel2);border:1px solid var(--line);border-radius:.9rem;
  padding:1.2rem 1.35rem;margin:1.3rem 0;position:relative;overflow:hidden}
.panel::before{content:"";position:absolute;left:0;top:0;bottom:0;width:.2rem;background:var(--line2)}
.panel.warn::before{background:var(--amber)} .panel.good::before{background:var(--good)} .panel.core::before{background:var(--lime)}
.panel h4{font-family:var(--sans);margin:.1rem 0 .5rem;font-size:1.05rem}
.panel p{font-size:clamp(1rem,1rem + .3vw,1.12rem)}
button.term{font:inherit;color:inherit;background:rgba(185,241,75,.1);border:none;border-bottom:1px dotted var(--lime);
  padding:0 .15rem;border-radius:.25rem;cursor:pointer}
button.term:hover{color:var(--lime)}

/* labs */
.labgrid{display:grid;grid-template-columns:1fr;gap:.9rem;margin:1.4rem 0}
.labcard{background:var(--panel);border:1px solid var(--line);border-radius:1rem;padding:1.1rem 1.15rem;min-width:0}
.labcard .ln{font-family:var(--mono);font-size:.7rem;color:var(--pro)}
.labcard .lt{font-family:var(--mono);font-size:.64rem;color:var(--faint);border:1px solid var(--line2);
  border-radius:999px;padding:.12rem .55rem;margin-left:.5rem;white-space:nowrap}
.labcard h3{font-size:.98rem;margin:.4rem 0}
.labcard p{font-size:.86rem;color:var(--muted);font-family:var(--sans);margin:.2rem 0 .6rem}
.labcard button{background:none;border:0;color:var(--amber);font-weight:700;cursor:pointer;
  padding:.6rem 0;min-height:2.75rem;font-size:.88rem}
.lab{background:linear-gradient(180deg,var(--panel2),var(--inset));border:1px solid var(--line2);
  border-radius:1.2rem;padding:clamp(1.1rem,2.5vw,1.8rem);margin:1.5rem 0;box-shadow:var(--shadow);min-width:0}
.lab>h3{margin-top:0;display:flex;align-items:center;gap:.55rem}
.lab>h3::before{content:"";width:.55rem;height:.55rem;border-radius:50%;background:var(--lime);box-shadow:0 0 .6rem var(--lime);flex:none}
.lab .hint{font-size:.88rem;color:var(--muted);font-family:var(--sans);max-width:76ch}
.controls{display:flex;flex-wrap:wrap;gap:.7rem;align-items:center;margin:1rem 0;font-family:var(--sans);font-size:.88rem}
.controls label{display:flex;gap:.55rem;align-items:center;background:var(--inset);border:1px solid var(--line);
  border-radius:.7rem;padding:.5rem .75rem;min-height:2.75rem;max-width:100%}
select{background:var(--panel2);color:var(--ink);border:1px solid var(--line2);border-radius:.55rem;
  padding:.55rem .65rem;font-size:.9rem;max-width:100%;min-height:2.75rem}
input[type=range]{accent-color:var(--lime);min-width:8rem;max-width:100%}
button.btn{font-family:var(--sans);font-weight:650;font-size:.88rem;border-radius:999px;padding:.65rem 1.25rem;
  border:1px solid var(--line2);background:var(--panel2);color:var(--ink);cursor:pointer;min-height:2.9rem;
  transition:transform .15s ease,border-color .15s ease}
button.btn:hover{border-color:var(--lime)}
button.btn:active{transform:scale(.97)}
button.btn.primary{background:var(--lime);border-color:var(--lime);color:var(--lime-ink)}
button.btn:disabled{opacity:.4;cursor:not-allowed}
.screen{background:var(--inset);border:1px solid var(--line);border-radius:.8rem;padding:.9rem;margin:.8rem 0;overflow-x:auto}
.tiles{display:grid;grid-template-columns:repeat(4,1fr);gap:.45rem;margin:0}
.tile{aspect-ratio:1/.72;border-radius:.5rem;display:flex;align-items:center;justify-content:center;
  font-family:var(--mono);font-size:.7rem;border:1px solid var(--line2);background:var(--panel);color:var(--muted)}
.tile.pass{background:rgba(126,226,168,.14);border-color:var(--good);color:var(--good)}
.tile.fail{background:rgba(255,125,125,.1);border-color:var(--bad);color:var(--bad)}
.advbars{display:flex;flex-direction:column;gap:.25rem;margin:.7rem 0;max-height:14rem;overflow:auto}
.advrow{display:flex;align-items:center;gap:.55rem;font-family:var(--mono);font-size:.68rem}
.advrow .lbl{min-width:4.4rem;color:var(--muted);flex:none}
.advrow .bar{height:.65rem;border-radius:.35rem;background:var(--good);min-width:2px}
.advrow .bar.neg{background:var(--bad)}
.simread{display:flex;flex-wrap:wrap;gap:.5rem 1.2rem;font-family:var(--mono);font-size:.8rem;margin:.7rem 0;
  background:var(--inset);border:1px solid var(--line);border-radius:.7rem;padding:.6rem .9rem}
.simread b{color:var(--lime)}
svg.fig{width:100%;display:block;background:var(--inset);border:1px solid var(--line);border-radius:.8rem}
svg.fig.trace{height:13rem} svg.fig.big{height:15rem}
svg.fig .gl{stroke:var(--line);stroke-width:1;opacity:.8}
svg.fig .glt{fill:var(--faint);font-size:10px;font-family:var(--mono)}
svg.fig .endv{font-size:11px;font-weight:700;font-family:var(--mono)}
svg.fig .pin line{stroke:var(--amber);stroke-width:1;opacity:.65}
svg.fig .pin text{fill:var(--amber);font-size:9.5px;font-family:var(--mono)}
svg.fig g.tip rect{fill:var(--panel2);stroke:var(--line2);stroke-width:1}
svg.fig g.tip text{fill:var(--ink);font-size:10.5px;font-family:var(--mono)}
svg.fig g.tip text:last-child{fill:var(--faint);font-size:9px}
svg.fig circle.pt{cursor:crosshair}
.exhibit{font-family:var(--sans);font-size:.92rem}
.exhibit pre{background:#05070c;color:#c9f2c9;border-radius:.6rem;padding:.9rem;overflow-x:auto;
  font-family:var(--mono);font-size:.78rem;line-height:1.6}
html[data-theme="light"] .exhibit pre{background:#101828;color:#d3f2c9}
.exhibit .verdict{display:grid;gap:.4rem;margin-top:.7rem}
.exhibit .verdict div{border:1px solid var(--line2);border-radius:.6rem;padding:.5rem .8rem;font-size:.86rem}

/* telemetry */
.tlegend{margin-left:auto;font-family:var(--mono);font-size:.72rem;color:var(--muted);white-space:nowrap}
.tlegend i{display:inline-block;width:1.4rem;height:.2rem;border-radius:.1rem;margin:0 .3rem 0 .8rem;vertical-align:middle}
.tlegend .p{background:var(--pro)} .tlegend .f{background:var(--flash)}
.telecontrols{margin:1rem 0}
.telecontrols .hint{font-size:.85rem;color:var(--faint);font-family:var(--sans)}
.telefocus{margin-bottom:1.2rem}
.telefocus .chartcard{border-color:var(--pro)}
.telegrid{display:grid;grid-template-columns:1fr;gap:1rem;align-items:start}
.chartcard{background:var(--panel);border:1px solid var(--line2);border-radius:1.1rem;
  padding:1.15rem clamp(1rem,2vw,1.5rem) 1.25rem;box-shadow:var(--shadow);min-width:0;container-type:inline-size}
.chartcard .chead{display:flex;flex-wrap:wrap;align-items:center;gap:.5rem .8rem;margin-bottom:.3rem}
.chartcard .fno{font-family:var(--mono);font-size:.68rem;color:var(--faint);border:1px solid var(--line2);
  border-radius:.4rem;padding:.12rem .45rem}
.chartcard .chead h3{margin:0;font-size:1rem;font-family:var(--mono);overflow-wrap:anywhere}
.chartcard .tag{font-family:var(--mono);font-size:.64rem;border:1px solid var(--line2);border-radius:999px;
  padding:.15rem .6rem;color:var(--faint);margin-left:auto;white-space:nowrap}
.chartcard .plain{font-size:.99rem;color:var(--muted);max-width:70ch}
.chartcard .plain b{color:var(--ink)}
.verdicts{display:grid;grid-template-columns:1fr;gap:.55rem;margin:.9rem 0}
.verdicts div{border:1px solid var(--line);border-radius:.65rem;padding:.55rem .7rem;font-size:.84rem;
  font-family:var(--sans);color:var(--muted);background:var(--inset)}
.verdicts b{display:block;font-family:var(--mono);font-size:.66rem;text-transform:uppercase;letter-spacing:.07em;margin-bottom:.2rem}
.verdicts .u b{color:var(--good)} .verdicts .d b{color:var(--bad)} .verdicts .w b{color:var(--amber)}
@container (min-width:26rem){.verdicts{grid-template-columns:repeat(3,1fr)}}
.chartcard .endstate{display:flex;flex-wrap:wrap;gap:.4rem;align-items:center;font-family:var(--mono);
  font-size:.74rem;color:var(--muted);border-top:1px dashed var(--line2);padding-top:.75rem;margin-top:.6rem}
.chartcard .endstate .pill{background:var(--inset);border:1px solid var(--line2);border-radius:999px;padding:.2rem .7rem}
textarea.feed{width:100%;min-height:5.5rem;background:var(--inset);color:var(--ink);border:1px solid var(--line2);
  border-radius:.7rem;padding:.75rem;font-family:var(--mono);font-size:.95rem;line-height:1.65}
.feedout{font-size:.94rem;margin:.9rem 0 0;padding-left:1.2rem;display:grid;gap:.35rem}
.feedout li::marker{color:var(--lime)}

/* timeline */
.timeline{list-style:none;margin:1.2rem 0;padding:0;display:grid;gap:.7rem}
.timeline li{display:grid;grid-template-columns:1.4rem 1fr;gap:.9rem;background:var(--panel);
  border:1px solid var(--line);border-radius:1rem;padding:1rem 1.1rem}
.timeline .dot2{width:.8rem;height:.8rem;border-radius:50%;margin-top:.45rem;background:var(--muted);flex:none}
.timeline li.crash .dot2{background:var(--bad);box-shadow:0 0 .7rem var(--bad)}
.timeline li.eval .dot2{background:var(--flash)}
.timeline li.shutdown .dot2{background:var(--amber);box-shadow:0 0 .7rem var(--amber)}
.timeline li.curriculum .dot2{background:var(--lime)}
.timeline .tw{font-family:var(--mono);font-size:.7rem;color:var(--faint)}
.timeline p{margin:.2rem 0 0;font-size:.96rem}

/* capstone */
.checklist{list-style:none;padding:0;margin:1.2rem 0;display:grid;gap:.55rem}
.checklist li{background:var(--panel);border:1px solid var(--line);border-radius:.8rem;
  padding:.7rem .95rem;display:flex;gap:.7rem;align-items:flex-start;font-family:var(--sans);font-size:.94rem}
.checklist input{margin-top:.3rem;min-width:1.4rem;min-height:1.4rem;accent-color:var(--lime);flex:none}
table.data{width:100%;border-collapse:collapse;font-family:var(--sans);font-size:.88rem;margin:1.2rem 0;
  background:var(--panel);border:1px solid var(--line);border-radius:.8rem;display:block;overflow-x:auto;max-width:100%}
table.data th,table.data td{text-align:left;padding:.6rem .75rem;border-bottom:1px solid var(--line);white-space:nowrap}
table.data th{font-family:var(--mono);font-size:.66rem;color:var(--faint);text-transform:uppercase;letter-spacing:.06em}

/* quiz modal: bottom sheet on phone, centered dialog on desktop */
.quizmodal{position:fixed;inset:0;z-index:150;display:flex;align-items:flex-end;justify-content:center;
  background:rgba(3,5,10,.7);padding:0}
.quizmodal[hidden]{display:none}
.quizbox{background:var(--panel2);border:1px solid var(--line2);border-radius:1.2rem 1.2rem 0 0;
  width:100%;max-height:94vh;max-height:94dvh;overflow:auto;padding:1.2rem clamp(1rem,3vw,1.8rem) 1.6rem;box-shadow:var(--shadow)}
.quiztop{display:flex;align-items:center;gap:.8rem}
.quizdots{display:flex;gap:.35rem;flex:1;flex-wrap:wrap}
.quizdots i{width:1.6rem;height:.45rem;border-radius:.25rem;background:var(--line2)}
.quizdots i.hit{background:var(--good)} .quizdots i.miss{background:var(--bad)} .quizdots i.cur{background:var(--pro)}
.quizbox .x{margin-left:auto;background:none;border:1px solid var(--line2);color:var(--muted);border-radius:.6rem;
  min-width:2.75rem;min-height:2.75rem;cursor:pointer;font-size:1.1rem;flex:none}
.quizbar{height:.4rem;background:var(--inset);border-radius:.25rem;margin:.8rem 0;overflow:hidden}
.quizbar i{display:block;height:100%;width:0;background:linear-gradient(90deg,var(--pro),var(--flash));transition:width .25s ease}
.quizstage{transition:opacity .22s ease,transform .22s ease}
.quizstage.fade{opacity:0;transform:translateX(1.2rem)}
.quizstage h3{font-size:clamp(1.05rem,1rem + 1vw,1.4rem);line-height:1.45}
.quizopts{display:grid;gap:.55rem;margin-top:1rem}
.quizopt{display:flex;gap:.7rem;align-items:flex-start;text-align:left;background:var(--inset);
  border:1px solid var(--line2);color:var(--ink);border-radius:.8rem;padding:.8rem 1rem;cursor:pointer;
  min-height:3.25rem;font-size:.95rem;font-family:var(--sans);width:100%}
.quizopt:hover:not(:disabled){border-color:var(--lime)}
.quizopt .k{flex:none;width:1.7rem;height:1.7rem;border-radius:50%;border:1px solid var(--line2);
  display:flex;align-items:center;justify-content:center;font-family:var(--mono);font-size:.75rem}
.quizopt.right{border-color:var(--good);background:rgba(126,226,168,.1)}
.quizopt.wrong{border-color:var(--bad);background:rgba(255,125,125,.08)}
.quizwhy{display:none;margin-top:.8rem;border-left:.15rem solid var(--lime);padding-left:.8rem;color:var(--muted);font-size:.9rem}
.quizstage.answered .quizwhy{display:block}
.quiznav{display:flex;align-items:center;gap:.7rem;margin-top:1.1rem;flex-wrap:wrap}
.quizscore{margin:0 auto;font-size:.82rem;color:var(--muted);font-family:var(--mono)}
.quizresult h3{font-size:1.4rem}
.scorering{font-family:var(--mono);font-size:clamp(2.4rem,2rem + 3vw,3.4rem);color:var(--lime)}
.review{list-style:none;padding:0;display:grid;gap:.6rem;margin-top:1rem}
.review li{border:1px solid var(--line);border-radius:.7rem;padding:.7rem .9rem;font-size:.88rem;font-family:var(--sans)}
.review li.bad{border-color:var(--bad)} .review li.good{border-color:var(--good)}
.review .why{color:var(--muted);font-size:.84rem}

/* drawer + mobilebar + footer */
.drawer{position:fixed;right:1rem;bottom:5rem;z-index:140;max-width:min(25rem,calc(100vw - 2rem));
  background:var(--panel2);border:1px solid var(--line2);border-radius:.9rem;padding:1.1rem 1.3rem;
  box-shadow:var(--shadow);display:none;font-family:var(--sans)}
.drawer.open{display:block}
.drawer h4{margin:.1rem 2rem .35rem 0;color:var(--lime);font-size:.95rem}
.drawer p{font-size:.9rem;line-height:1.65}
.drawer .x{position:absolute;top:.4rem;right:.5rem;background:none;border:0;color:var(--muted);
  font-size:1.1rem;min-width:2.75rem;min-height:2.75rem;cursor:pointer}
.mobilebar{position:fixed;left:0;right:0;bottom:0;z-index:100;display:flex;background:var(--bg);
  border-top:1px solid var(--line);padding:.4rem .4rem calc(.4rem + env(safe-area-inset-bottom))}
.mobilebar a{flex:1;display:flex;flex-direction:column;align-items:center;gap:.1rem;text-decoration:none;
  color:var(--muted);font-size:1rem;padding:.5rem 0;min-height:3.25rem;font-family:var(--sans)}
.mobilebar a span{font-size:.62rem}
.mobilebar a:hover{color:var(--ink)}
.mobilebar button{flex:1;display:flex;flex-direction:column;align-items:center;gap:.1rem;background:none;border:0;
  color:var(--muted);font-size:1rem;padding:.5rem 0;min-height:3.25rem;font-family:var(--sans);cursor:pointer}
.mobilebar button span{font-size:.62rem}
footer{position:relative;z-index:1;border-top:1px solid var(--line);padding:2rem clamp(1rem,4vw,3rem) 6rem;
  color:var(--faint);font-family:var(--sans);font-size:.84rem;text-align:center}

/* tablet and up */
@media (min-width:48rem){
  .hero{grid-template-columns:minmax(0,1.05fr) minmax(0,.95fr);align-items:start}
  .runcards{grid-template-columns:1fr 1fr}
  .hero .runcards{grid-template-columns:1fr}
  .chapgrid{grid-template-columns:repeat(2,1fr)}
  .labgrid{grid-template-columns:repeat(2,1fr)}
  .telegrid{grid-template-columns:repeat(2,1fr)}
  .facts{grid-template-columns:repeat(4,1fr)}
  .tiles{grid-template-columns:repeat(8,1fr)}
  .verdicts{grid-template-columns:repeat(3,1fr)}
  .mobilebar{display:none}
  footer{padding-bottom:2.5rem}
  .quizmodal{align-items:center;padding:1.5rem}
  .quizbox{border-radius:1.2rem;max-width:44rem}
  .drawer{bottom:1rem}
}
/* laptop and up */
@media (min-width:64rem){
  .chapgrid{grid-template-columns:repeat(4,1fr)}
  .labgrid{grid-template-columns:repeat(5,1fr)}
  .hero-side{position:sticky;top:9rem}
}
@media (max-width:47.99rem){
  /* phone: brand row, then full-width 5-up nav; theme lives in the bottom bar zone */
  .topbar{flex-wrap:wrap}
  .headctl{flex-basis:100%;margin-left:0;display:block}
  .headctl .themebox{display:none}
  main{padding-bottom:5.5rem}
}
/* desktop */
@media (min-width:90rem){
  body{font-size:clamp(1.1rem,1.02rem + .4vw,1.32rem)}
  .telegrid{grid-template-columns:repeat(3,1fr)}
  .wrap{max-width:120rem}
}
/* 4K */
@media (min-width:125rem){
  .wrap{max-width:150rem}
  body{font-size:1.4rem}
  h1{font-size:4.6rem}
  .telegrid{grid-template-columns:repeat(4,1fr)}
  svg.fig.trace{height:14rem} svg.fig.big{height:17rem}
  .quizbox{max-width:56rem}
}

/* chapter mode toggle: lives INSIDE each chapter, not the header */
.chmodetoggle{display:flex;background:var(--inset);border:1px solid var(--line2);border-radius:999px;
  padding:.25rem;gap:.25rem;max-width:30rem;margin:1.2rem 0}
.chmodetoggle .seg{flex:1;text-align:center}
.chapbody[data-track="eng"]{border-left:.2rem solid var(--flash);padding-left:clamp(.9rem,2vw,1.4rem)}
.chapbody[data-track="eli5"]{border-left:.2rem solid var(--lime);padding-left:clamp(.9rem,2vw,1.4rem)}

/* site nav (multipage) */
.sitenav{display:flex;gap:.25rem;scrollbar-width:none}
.sitenav::-webkit-scrollbar{display:none}
.sitenav a{flex:1 1 auto;text-decoration:none;color:var(--muted);font-family:var(--sans);font-size:.86rem;font-weight:600;
  border-radius:.7rem;padding:.6rem .5rem;min-height:2.75rem;display:flex;align-items:center;justify-content:center;text-align:center;white-space:nowrap;min-width:0}
.sitenav a:hover{color:var(--ink)}
.sitenav a.on{color:var(--pro);background:var(--panel2)}
.headctl .sitenav{flex:1 1 auto;min-width:0}

/* homepage curiosity + how cards */
.curgrid{display:grid;grid-template-columns:1fr;gap:.9rem;margin:1.4rem 0}
.curcard{display:block;text-decoration:none;background:var(--panel);border:1px solid var(--line);
  border-radius:1rem;padding:1.1rem 1.2rem;color:var(--ink)}
.curcard:hover{border-color:var(--line2)}
.curcard b{display:block;font-family:var(--sans);font-size:1rem;margin-bottom:.3rem}
.curcard span{color:var(--muted);font-family:var(--sans);font-size:.9rem}
.howgrid{display:grid;grid-template-columns:1fr;gap:.9rem;margin:1.4rem 0}
.howcard{background:var(--panel);border:1px solid var(--line);border-radius:1rem;padding:1.1rem 1.2rem}
.howcard b{display:block;font-family:var(--sans);margin-bottom:.3rem}
.howcard span{color:var(--muted);font-family:var(--sans);font-size:.92rem}

/* chapter reader chrome */
.crumbs{display:flex;gap:.6rem;align-items:center;font-family:var(--sans);font-size:.88rem;margin-bottom:1.2rem}
.crumbs a{color:var(--muted);text-decoration:none}
.crumbs a:hover{color:var(--ink)}
.chapnav{display:grid;grid-template-columns:1fr;gap:.7rem;margin-top:2rem}
.btn.ghostbtn{display:inline-flex;align-items:center;justify-content:center;font-family:var(--sans);font-weight:650;
  border:1px solid var(--line2);border-radius:999px;padding:.7rem 1.3rem;color:var(--ink);text-decoration:none;min-height:2.9rem}
.btn.primarybtn{display:inline-flex;align-items:center;justify-content:center;font-family:var(--sans);font-weight:700;
  background:var(--lime);color:var(--lime-ink);border-radius:999px;padding:.7rem 1.3rem;text-decoration:none;min-height:2.9rem}
.labslot:empty{display:none}
.golab{display:inline-block;color:var(--amber);font-weight:700;text-decoration:none;padding:.6rem 0;min-height:2.75rem;font-size:.88rem;font-family:var(--sans)}
@media (min-width:48rem){
  .curgrid{grid-template-columns:repeat(2,1fr)}
  .howgrid{grid-template-columns:repeat(3,1fr)}
  .chapnav{grid-template-columns:1fr auto 1fr}
}
@media (min-width:64rem){
  .curgrid{grid-template-columns:repeat(3,1fr)}
}