/* Layout: one long night-sky scroll — a pinned title scene, then a pinned nerve diagram that changes with each step, then plain reading sections. */
:root{
  --bg:#04080f; --bg2:#0a1422; --ink:#e8f1f8; --muted:#8ea3b8; --line:rgba(143,214,208,.18);
  --cyan:#5fd4ff; --teal:#8fd6d0; --amber:#ffb547; --red:#ff6b6b; --good:#4fd18b;
  --f:"Cairo",system-ui,"Segoe UI",Tahoma,sans-serif;
  color-scheme:dark;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--ink);font:400 17px/1.8 var(--f);overflow-x:hidden}
.wrap{max-width:1080px;margin:0 auto;padding-left:max(16px,env(safe-area-inset-left,0px));padding-right:max(16px,env(safe-area-inset-right,0px))}
#sky{position:fixed;inset:0;width:100%;height:100%;z-index:0;pointer-events:none}
main{position:relative;z-index:1}
.eyebrow{font-size:13px;font-weight:700;letter-spacing:.06em;color:var(--teal);margin:0 0 6px}
h2{font-size:clamp(26px,4.4vw,40px);line-height:1.25;font-weight:900;margin:0 0 14px;text-wrap:balance}
p{margin:0}
.term{direction:ltr;unicode-bidi:isolate;font-weight:700;color:var(--cyan)}

/* ---------- 1. title scene ---------- */
.hero{height:280vh;position:relative}
.stage{position:sticky;top:0;height:100vh;height:100svh;display:grid;place-items:center;overflow:hidden;padding-left:max(16px,env(safe-area-inset-left,0px));padding-right:max(16px,env(safe-area-inset-right,0px))}
.scene{position:relative;width:100%;max-width:1000px;text-align:center}
.full{direction:ltr;margin:0;font-weight:900;font-size:clamp(30px,6.4vw,76px);line-height:1.12;letter-spacing:-.01em}
.word{display:inline-block;white-space:nowrap;margin:0 .14em}
.ch{display:inline-block;transform-origin:0 0;will-change:transform,opacity;
  background:linear-gradient(180deg,#f4f7fb 0%,#9ba7b6 100%);-webkit-background-clip:text;background-clip:text;color:transparent}
.ch.kch{background:linear-gradient(180deg,#bff0ff 0%,var(--cyan) 100%);-webkit-background-clip:text;background-clip:text;text-shadow:0 0 30px rgba(95,212,255,.25)}
.ar-name{margin-top:18px;font-size:clamp(20px,3.2vw,30px);font-weight:800}
.def{max-width:56ch;margin:10px auto 0;color:var(--muted);font-size:clamp(15px,2vw,18px)}
.reveal-late{opacity:var(--late,0);transform:translateY(calc((1 - var(--late,0)) * 14px))}
.hint{position:absolute;bottom:calc(26px + env(safe-area-inset-bottom,0px));left:50%;transform:translateX(-50%);font-size:13px;color:var(--muted);display:flex;flex-direction:column;align-items:center;gap:6px;opacity:var(--hint,1)}
.hint i{width:1px;height:34px;background:linear-gradient(var(--cyan),transparent);animation:drip 1.8s ease-in-out infinite}
@keyframes drip{0%{transform:scaleY(0);transform-origin:top}50%{transform:scaleY(1);transform-origin:top}51%{transform-origin:bottom}100%{transform:scaleY(0);transform-origin:bottom}}

/* ---------- 2. nerve diagram (pinned) ---------- */
.nerves{position:relative;padding-block:10vh 4vh}
.nv-grid{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1.05fr);gap:40px;align-items:start}
.fig{position:sticky;top:max(10vh,56px);height:min(80vh,680px);display:block;margin:0}
.holo{position:relative;width:100%;height:100%;max-width:460px;margin:0 auto}
.holo canvas{position:absolute;inset:0;width:100%;height:100%}
.holo::after{content:"";position:absolute;inset:0;pointer-events:none;background:repeating-linear-gradient(0deg,rgba(95,212,255,.035) 0 1px,transparent 1px 3px);mix-blend-mode:screen;border-radius:24px}
.holo .base{position:absolute;left:12%;right:12%;bottom:1%;height:8%;border-radius:50%;background:radial-gradient(closest-side,rgba(95,212,255,.22),transparent);filter:blur(2px)}
.lbl{position:absolute;transform:translate(-50%,-50%);font:800 13px var(--f);white-space:nowrap;padding:3px 9px;border-radius:999px;border:1px solid currentColor;background:rgba(4,8,15,.72);opacity:0;transition:opacity .5s,transform .5s;pointer-events:none}
.lbl.on{opacity:1}
.lbl.dim{opacity:.55;color:var(--muted)!important}
.l-c{color:var(--cyan)}.l-a{color:var(--amber)}.l-r{color:var(--red)}.l-g{color:var(--good)}.l-m{color:#b9c8d6;border-color:transparent;background:none;font-weight:700}
.legend{position:absolute;inset-inline-end:2%;top:2%;display:flex;flex-direction:column;gap:4px;font-size:12px;color:var(--muted)}
.legend i{display:inline-block;width:18px;height:3px;border-radius:2px;margin-inline-end:6px;vertical-align:middle}
.steps{display:grid;gap:0}
.step{min-height:82vh;display:flex;flex-direction:column;justify-content:center;gap:12px;opacity:.55;transition:opacity .5s,transform .5s;transform:translateX(0)}
.step.on{opacity:1}
.step.on h2{text-shadow:0 0 28px rgba(95,212,255,.35)}
.step.on .pill{border-color:rgba(95,212,255,.45);background:rgba(12,26,44,.85)}
.step .num{font-weight:900;font-size:14px;color:var(--teal)}
.pair{display:grid;gap:10px;margin-top:6px}
.pill{border:1px solid var(--line);background:rgba(10,20,34,.72);border-radius:14px;padding:12px 14px;backdrop-filter:blur(4px)}
.pill b{display:block;font-size:16px}
.pill small{display:block;color:var(--muted);font-size:14px;line-height:1.7}
.pill.motor b{color:var(--cyan)} .pill.sens b{color:var(--amber)} .pill.bad b{color:var(--red)} .pill.ok b{color:var(--good)}
/* ---------- 3. reading sections ---------- */
.sec{padding-block:12vh 4vh}
.lead{color:var(--muted);max-width:60ch}
.timeline{position:relative;margin-top:28px;display:grid;gap:22px;padding-inline-start:34px}
.timeline::before{content:"";position:absolute;inset-inline-start:10px;top:6px;bottom:6px;width:2px;background:var(--line)}
.timeline .fill{position:absolute;inset-inline-start:10px;top:6px;width:2px;height:calc(var(--tl,0) * (100% - 12px));background:linear-gradient(var(--cyan),var(--red))}
.tl{position:relative;display:grid;gap:2px}
.tl::before{content:"";position:absolute;inset-inline-start:-30px;top:8px;width:14px;height:14px;border-radius:50%;background:var(--bg);border:2px solid var(--muted);transition:border-color .4s,background .4s}
.tl.hit::before{border-color:var(--cyan);background:var(--cyan)}
.tl:last-child.hit::before{border-color:var(--red);background:var(--red)}
.tl b{font-size:18px} .tl span{color:var(--muted)}
.cards{display:grid;grid-template-columns:repeat(auto-fit,minmax(min(100%,240px),1fr));gap:14px;margin-top:22px}
.card{border:1px solid var(--line);background:rgba(10,20,34,.75);border-radius:16px;padding:18px;display:grid;gap:6px;align-content:start}
.card b{font-size:18px}
.card p{color:var(--muted);font-size:15px}
.card .k{font-size:13px;font-weight:800;color:var(--teal)}
.key{margin-top:22px;border:1px solid rgba(95,212,255,.45);background:linear-gradient(90deg,rgba(95,212,255,.10),rgba(95,212,255,.02));border-radius:16px;padding:16px 18px;display:flex;gap:14px;align-items:center;flex-wrap:wrap}
.key big{font-size:clamp(28px,5vw,40px);font-weight:900;color:var(--cyan);direction:ltr}
.key span{flex:1;min-width:0}
.tbl{overflow-x:auto;margin-top:22px;border:1px solid var(--line);border-radius:16px}
table{border-collapse:collapse;width:100%;min-width:560px;font-size:15px}
th,td{padding:14px 16px;text-align:start;vertical-align:top;border-bottom:1px solid var(--line)}
th{font-size:13px;color:var(--muted);font-weight:700;letter-spacing:.03em}
tr:last-child td{border-bottom:0}
td:first-child{font-weight:800;white-space:nowrap}
tr.als td{background:rgba(95,212,255,.07)}
tr.als td:first-child{color:var(--cyan)}
.yes{color:var(--good);font-weight:700}.no{color:var(--red);font-weight:700}
.tip{margin-top:18px;color:var(--muted);font-size:15px}
footer{padding-block:8vh 6vh;text-align:center;color:var(--muted);font-size:14px}
footer b{color:var(--ink)}
.fadein{opacity:.35;transform:translateY(16px);transition:opacity .8s,transform .8s}
.fadein.in{opacity:1;transform:none}

@media (max-width:820px){
  .nv-grid{grid-template-columns:1fr;gap:0}
  .fig{top:0;height:46vh;z-index:5;background:var(--bg);box-shadow:0 18px 24px var(--bg);isolation:isolate;margin-inline:calc(-1 * max(16px,env(safe-area-inset-left,0px)));padding-top:env(safe-area-inset-top,0px)}
  .step{min-height:62vh;justify-content:center;position:relative;z-index:1}
}
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}.hero{height:auto}.stage{position:relative;height:auto;padding-block:16vh}
  .reveal-late{opacity:1;transform:none}.hint{display:none}.fadein{opacity:1;transform:none}
  .fig .mus,.hint i{animation:none!important}
}
:focus-visible{outline:2px solid var(--cyan);outline-offset:3px}

.brand{position:fixed;top:calc(12px + env(safe-area-inset-top,0px));inset-inline-start:max(16px,env(safe-area-inset-left,0px));z-index:20;display:flex;align-items:center;gap:8px;color:var(--ink);text-decoration:none;inset-inline-start:auto;right:max(16px,env(safe-area-inset-right,0px));font-weight:900;font-size:17px;letter-spacing:.01em;direction:ltr}
.brand img{width:28px;height:28px}
.tools{position:fixed;top:calc(12px + env(safe-area-inset-top,0px));left:max(16px,env(safe-area-inset-left,0px));z-index:20;display:flex;gap:8px}
.tbtn{font:700 13px var(--f);color:var(--ink);background:rgba(10,20,34,.8);border:1px solid var(--line);border-radius:999px;padding:7px 14px;cursor:pointer;text-decoration:none}
.tbtn:hover{border-color:var(--cyan)}
.nav{position:fixed;bottom:calc(14px + env(safe-area-inset-bottom,0px));left:max(16px,env(safe-area-inset-left,0px));direction:ltr;z-index:20;display:flex;align-items:center;gap:8px;font:700 13px var(--f);color:var(--muted)}
.nav button{width:40px;height:40px;border-radius:50%;border:1px solid var(--line);background:rgba(10,20,34,.85);color:var(--ink);font-size:18px;cursor:pointer}
.nav button:hover{border-color:var(--cyan)}
.wm{position:fixed;bottom:calc(16px + env(safe-area-inset-bottom,0px));inset-inline-start:max(16px,env(safe-area-inset-left,0px));z-index:20;font:800 12px var(--f);color:rgba(143,214,208,.55);direction:ltr}
.toast{position:fixed;left:50%;bottom:80px;transform:translateX(-50%);background:rgba(10,20,34,.95);border:1px solid var(--cyan);color:var(--ink);padding:8px 16px;border-radius:999px;font:700 14px var(--f);z-index:30;opacity:0;transition:opacity .3s;pointer-events:none}
.toast.on{opacity:1}
:fullscreen .tools .share{display:none}
.holo{position:relative;width:100%;height:100%;max-width:460px;margin:0 auto}
@media (max-width:820px){.wm{display:none}.nav{bottom:calc(10px + env(safe-area-inset-bottom,0px))}}

.wm{display:none}
@media (max-width:820px){.brand{font-size:0;gap:0}.brand img{width:30px;height:30px}.tools .tbtn{padding:6px 11px;font-size:12px}}
@media (max-width:820px){.fig{height:calc(44vh + 54px);padding-top:calc(54px + env(safe-area-inset-top,0px))}}
html[data-l="en"] .ar{display:none!important}
html:not([data-l="en"]) .en{display:none!important}
html[dir="ltr"] .brand{right:auto;left:max(16px,env(safe-area-inset-left,0px))}
html[dir="ltr"] .tools{left:auto;right:max(16px,env(safe-area-inset-right,0px))}
html[dir="ltr"] .nav{left:auto;right:max(16px,env(safe-area-inset-right,0px))}
html[lang="en"] .def,html[lang="en"] .pill small,html[lang="en"] .card p{line-height:1.6}
.tbtn.lang{min-width:40px;font-weight:900}
@media (max-width:820px){.tools #fs{display:none}}
.l-w{color:#e8f1f8}.l-v{color:#ff6e8c}.l-p{color:#be96ff}
html,body{overflow-x:clip}
.rel-links{display:flex;flex-wrap:wrap;gap:8px;margin-top:14px}
.rel-links a{border:1px solid var(--line);background:rgba(10,20,34,.75);border-radius:999px;padding:6px 14px;color:var(--ink);text-decoration:none;font-size:14px;font-weight:700}
.rel-links a:hover{border-color:var(--cyan);color:var(--cyan)}
.adsbygoogle,ins.adsbygoogle{position:relative;z-index:2}
.l-b{color:#5a96ff}.l-t{color:var(--teal)}

.soc{display:flex;gap:10px;justify-content:center;margin:10px 0 6px}.soc a{display:inline-flex;align-items:center;gap:6px;padding:6px 12px;border:1px solid var(--line);border-radius:999px;color:inherit;text-decoration:none;font-weight:700;font-size:13px}.soc a:hover{border-color:currentColor}