/* Learn pages (learn.php, learn.js, lib/learn-art.php). Everything is lr-*; nothing here touches the other pages. */
.lr-main{--lr-mid:#c3cfe6;--lr-ink:#f4f7ff;--lr-card:linear-gradient(180deg,var(--panel2),var(--panel))}
.lr-main button{font:inherit;color:inherit;cursor:pointer}
.lr-main :focus-visible{outline:2px solid var(--cyan);outline-offset:2px}
/* needs JavaScript: hidden until learn.js has run */
.lr-needjs{display:none}
.lr-js .lr-needjs{display:block}
.lr-js .lr-tools.lr-needjs{display:flex}
.lr-js .lr-chips.lr-needjs{display:flex}
.lr-js.lv-simple .lr-detail,.lr-js.lv-detail .lr-simple{display:none}

/* hub hero */
.lr-hero{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1.05fr);gap:28px;align-items:center;padding:6px 0 28px}
.lr-hero h1{margin:0 0 14px;font-family:var(--display);font-weight:700;font-size:clamp(2.6rem,6vw,4.4rem);line-height:.98;letter-spacing:.01em}
.lr-hero h1 em{font-style:normal;color:var(--amber)}
.lr-lead{margin:0 0 20px;max-width:34em;font-size:1.12rem;line-height:1.55;color:var(--lr-mid)}
.lr-tools{gap:14px;flex-wrap:wrap;align-items:center}
.lr-seg{display:inline-flex;border:1px solid var(--line2);border-radius:999px;padding:3px;background:var(--bg2)}
.lr-seg button{border:0;background:transparent;padding:7px 16px;border-radius:999px;color:var(--muted);font-weight:600}
.lr-seg button[aria-pressed=true]{background:var(--amber);color:#1a1200}
.lr-prog{display:flex;align-items:center;gap:10px;color:var(--lr-mid);font-size:.9rem}
.lr-ring{width:44px;height:44px;transform:rotate(-90deg)}
.lr-ring circle{fill:none;stroke-width:5}
.lr-ring .bg{stroke:var(--line2)}
.lr-ring .fg{stroke:var(--green);stroke-linecap:round;transition:stroke-dashoffset .6s}
.lr-scene{position:relative;border:1px solid var(--line2);border-radius:16px;background:linear-gradient(180deg,#0a1226 0%,#0b1830 60%,#0a1a22 100%);overflow:hidden}
.lr-scene svg{display:block;width:100%;height:auto}
.lr-runway-l{position:absolute;left:60.5%;bottom:11%;font:.72rem var(--mono);color:var(--muted);letter-spacing:.06em}
.lr-bubble{position:absolute;left:14px;top:14px;max-width:62%;margin:0;min-height:38px;padding:8px 12px;background:rgba(8,13,22,.88);border:1px solid var(--line2);border-radius:10px;font:.85rem var(--mono);color:var(--text);transition:border-color .2s}
.lr-bubble.warn{border-color:var(--amber);color:var(--amber)}
.lr-scene-note{position:absolute;right:12px;bottom:8px;margin:0;font:.72rem var(--mono);color:var(--muted)}

/* topic cards */
.lr-sech{display:flex;justify-content:space-between;align-items:end;gap:12px;flex-wrap:wrap;margin:0 0 14px}
.lr-sech h2,.lr-more h2{margin:0;font-family:var(--display);font-weight:700;font-size:1.9rem;letter-spacing:.03em;line-height:1}
.lr-chips{gap:8px;flex-wrap:wrap}
.lr-chip{border:1px solid var(--line2);background:var(--bg2);border-radius:999px;padding:6px 14px;font-size:.9rem;color:var(--lr-mid)}
.lr-chip[aria-pressed=true]{border-color:var(--amber);color:var(--amber);background:#1a1606}
.lr-cards{display:grid;grid-template-columns:repeat(5,minmax(0,1fr));gap:12px;list-style:none;margin:0;padding:0}
.lr-cards4{grid-template-columns:repeat(4,minmax(0,1fr))}
.lr-cards li[hidden]{display:none}
.lr-card{position:relative;display:flex;flex-direction:column;height:100%;border:1px solid var(--line2);border-radius:14px;background:var(--lr-card);overflow:hidden;text-decoration:none;color:var(--text);transition:transform .15s,border-color .15s}
.lr-card:hover{transform:translateY(-3px);border-color:var(--cyan)}
.lr-art{display:block;height:92px;border-bottom:1px solid var(--line);background:#070c17;overflow:hidden}
.lr-art svg{display:block;width:100%;height:100%}
.lr-ct{display:grid;gap:4px;padding:10px 12px 12px}
.lr-ct b{font-family:var(--display);font-weight:600;font-size:1.12rem;line-height:1.15;letter-spacing:.02em}
.lr-cm{font:.74rem var(--mono);color:var(--muted)}
.lr-tick{position:absolute;right:8px;top:8px;display:none;place-items:center;width:22px;height:22px;border-radius:50%;background:var(--green);color:#052;font-weight:800;font-size:.85rem}
.lr-card.done .lr-tick{display:grid}
.lr-card.here{border-color:var(--amber)}

/* topic page */
.lr-th{display:flex;flex-wrap:wrap;gap:10px 24px;justify-content:space-between;align-items:center;margin:0 0 16px}
.lr-th h1{margin:0;font-family:var(--display);font-weight:700;font-size:clamp(2rem,5vw,3rem);line-height:1.04;letter-spacing:.02em}
.lr-pb{display:grid;grid-template-columns:minmax(0,5fr) minmax(0,7fr);gap:26px;align-items:start}
.lr-copy p{margin:0 0 12px;color:var(--lr-mid);max-width:38em;line-height:1.6}
.lr-copy p.lr-big{font-size:1.15rem;color:var(--text)}
.lr-copy h2{margin:18px 0 6px;font-family:var(--display);font-weight:600;font-size:1.3rem;letter-spacing:.04em;color:var(--amber)}
.lr-copy .pv-list{margin:0 0 12px}
.lr-fact{margin:16px 0;padding:12px 14px;border-left:3px solid var(--cyan);background:#0a1a28;border-radius:0 10px 10px 0;color:var(--lr-mid);font-size:.95rem;line-height:1.5}
.lr-fact b{display:block;color:var(--cyan);font-family:var(--display);font-size:1.08rem;letter-spacing:.04em}
.lr-watch{margin-top:14px;padding:12px 14px;border:1px dashed var(--line2);border-radius:10px;color:var(--lr-mid);font-size:.95rem;line-height:1.5}
.lr-watch b{color:var(--amber)}
.lr-quiz{margin:18px 0;padding:14px;border:1px solid var(--line2);border-radius:12px;background:var(--panel)}
.lr-quiz h2{margin:0 0 10px;font-family:var(--display);font-weight:600;font-size:1.25rem;letter-spacing:.02em;color:var(--text)}
.lr-opts{display:grid;gap:8px}
.lr-opts button{text-align:left;border:1px solid var(--line2);background:#0a1020;border-radius:10px;padding:9px 12px}
.lr-opts button:hover:not(:disabled){border-color:var(--cyan)}
.lr-opts button.right{border-color:var(--green);background:#0c2218}
.lr-opts button.wrong{border-color:var(--red);background:#271013}
.lr-why{margin:8px 0 0!important;min-height:1.4em;font-size:.95rem}
.lr-why .y{color:var(--green)}.lr-why .n{color:var(--red)}
.lr-pn{display:grid;grid-template-columns:1fr auto 1fr;gap:12px;align-items:stretch;margin:26px 0 8px}
.lr-pn a{display:grid;gap:2px;align-content:center;padding:12px 16px;border:1px solid var(--line2);border-radius:12px;background:var(--lr-card);color:var(--text);text-decoration:none}
.lr-pn a:hover{border-color:var(--cyan)}
.lr-pn a span{font:.72rem var(--mono);color:var(--muted)}
.lr-pn a b{font-family:var(--display);font-weight:600;font-size:1.1rem;letter-spacing:.02em}
.lr-pn a[rel=next]{text-align:right}
.lr-pn .lr-all{align-content:center;text-align:center;color:var(--lr-mid)}
.lr-more{margin:26px 0 6px}.lr-more h2{margin-bottom:12px}

/* the lab */
.lr-lab{border:1px solid var(--line2);border-radius:14px;background:#060b15;padding:14px}
.lr-lab h3{margin:0 0 8px;font:.82rem var(--mono);letter-spacing:.08em;text-transform:uppercase;color:var(--muted)}
.lr-lab svg{display:block;width:100%;height:auto;touch-action:none}
.lr-row{display:flex;gap:10px;flex-wrap:wrap;align-items:center;margin:10px 0 0}
.lr-btn{border:1px solid var(--line2);background:var(--panel2);border-radius:10px;padding:8px 14px;font-weight:600}
.lr-btn:hover:not(:disabled){border-color:var(--cyan)}
.lr-btn:disabled{opacity:.4;cursor:default}
.lr-btn.pri{background:var(--amber);border-color:var(--amber);color:#1a1200}
.lr-btn[aria-pressed=true]{border-color:var(--amber);color:var(--amber);background:#1a1606}
.lr-read{margin-top:10px;min-height:3em;padding:10px 12px;background:var(--panel);border:1px solid var(--line);border-radius:10px;font-size:.95rem;line-height:1.5;color:var(--lr-mid)}
.lr-read:empty{display:none}
.lr-read b{color:var(--text)}.lr-read .am{color:var(--amber)}.lr-read .ok{color:var(--green)}.lr-read .bad{color:var(--red)}
.lr-lab input[type=range]{width:100%;accent-color:var(--amber)}
.lr-lbl{display:flex;justify-content:space-between;margin-top:8px;font:.8rem var(--mono);color:var(--muted)}
.lr-check{display:flex;gap:8px;align-items:center;color:var(--lr-mid)}
.lr-hold{display:grid;grid-template-columns:minmax(0,1fr) 150px;gap:12px;align-items:stretch}
.lr-stack{position:relative;min-height:250px;border-left:1px dashed var(--line2)}
.lr-stack .lvl{position:absolute;left:0;right:0;padding-right:4px;border-top:1px solid var(--line);font:.62rem/1.1 var(--mono);color:#5d6f94;text-align:right}
.lr-stack .pl{position:absolute;left:8px;right:56px;height:26px;display:flex;align-items:center;gap:6px;font:.75rem var(--mono);color:var(--text);transition:top .9s ease,opacity .5s,transform .9s}
.lr-stack .pl i{display:block;width:12px;height:12px;border-radius:3px}
.lr-stack .pl.out{opacity:0;transform:translateX(30px)}
/* flight levels */
.lr-ladder{position:relative;height:330px;margin:4px 6px 4px 64px;border-left:2px solid var(--line2);background:linear-gradient(0deg,#0b2a1b 0,#0b2a1b 3px,transparent 3px)}
.lr-ladder .mk{position:absolute;left:0;width:100%;border-top:1px dashed var(--line);font:.75rem var(--mono);color:var(--muted)}
.lr-ladder .mk span{position:absolute;left:12px;top:-9px;padding:0 6px;background:#060b15}
.lr-ladder .mk.ref span{color:var(--lr-mid)}
.lr-ladder .mk.tr{border-top:2px dashed var(--amber)}.lr-ladder .mk.tr span{color:var(--amber)}
.lr-ladder .tk{position:absolute;left:-60px;width:50px;text-align:right;font:.7rem var(--mono);color:var(--muted);transform:translateY(50%)}
.lr-ladder .ac{position:absolute;left:46%;width:44px;margin-left:-22px;transform:translateY(50%);transition:bottom .12s linear}
.lr-ladder .ac svg{width:44px;height:44px;filter:drop-shadow(0 0 8px rgba(56,200,255,.6))}
/* transponder */
.lr-xpdr{display:grid;gap:12px;padding:14px;background:#05070c;border:2px solid var(--line2);border-radius:14px}
.lr-scr{display:grid;grid-template-columns:repeat(4,1fr);gap:8px}
.lr-dg{display:grid;gap:6px;justify-items:center}
.lr-dg button{width:100%;padding:2px 0;border:1px solid var(--line2);background:var(--panel2);border-radius:8px;line-height:1.3}
.lr-dg output{display:block;width:100%;padding:6px 0;text-align:center;font:700 3.2rem/1.1 var(--mono);color:var(--green);background:#02140a;border:1px solid #0e3a22;border-radius:10px;text-shadow:0 0 12px rgba(76,214,148,.6)}
.lr-xpdr.em .lr-dg output{color:var(--red);background:#1a0505;border-color:#5a1414;text-shadow:0 0 14px rgba(232,87,79,.8);animation:lr-blink .9s steps(2) infinite}
.lr-radar{position:relative;aspect-ratio:2.6/1;margin-top:12px;border:1px solid var(--line2);border-radius:12px;background:radial-gradient(circle at 50% 100%,#08241a,#040a08 70%);overflow:hidden}
.lr-radar svg{position:absolute;inset:0;width:100%;height:100%}
/* callsign, wake, radio, tracking */
.lr-tabs{display:flex;gap:8px;flex-wrap:wrap;margin:10px 0 0}
.lr-bigplane text{font-family:var(--mono)}
.lr-letters{display:flex;flex-wrap:wrap;gap:8px;margin:10px 0 0;padding:0;list-style:none}
.lr-letters li{min-width:64px;padding:6px 8px;text-align:center;background:var(--panel);border:1px solid var(--line);border-radius:8px}
.lr-letters b{display:block;font:700 1.3rem/1.2 var(--mono);color:var(--amber)}
.lr-letters span{font:.72rem var(--mono);color:var(--lr-mid)}
.lr-text{width:100%;padding:10px 12px;background:#0a1020;border:1px solid var(--line2);border-radius:10px;color:var(--text);font:inherit;font-size:1.1rem}
.lr-phr{display:flex;gap:8px;flex-wrap:wrap;margin:10px 0 0}
.lr-bar{height:10px;margin-top:10px;background:var(--panel);border:1px solid var(--line);border-radius:6px;overflow:hidden}
.lr-bar i{display:block;height:100%;width:0;background:var(--cyan)}

@keyframes lr-spin{to{transform:rotate(360deg)}}
@keyframes lr-sink{0%{transform:translateY(0);opacity:1}100%{transform:translateY(130px);opacity:0}}
.lr-vx{transform-box:fill-box;transform-origin:center;animation:lr-spin 1.3s linear infinite}.lr-sk{animation:lr-sink 4.5s ease-in infinite}
@keyframes lr-blink{50%{opacity:.45}}
@keyframes lr-go{to{offset-distance:100%}}
@keyframes lr-sway{0%,100%{transform:rotate(-50deg)}50%{transform:rotate(50deg)}}
@keyframes lr-hl{0%,60%,100%{stroke-width:1;opacity:.6}20%,40%{stroke-width:3;opacity:1}}
@keyframes lr-ripple{from{transform:scale(1);opacity:1}to{transform:scale(5);opacity:0}}
@keyframes lr-ping{from{transform:scale(1);opacity:1}to{transform:scale(6);opacity:0}}
@keyframes lr-climb{0%,100%{cy:80}50%{cy:14}}
@keyframes lr-bar{0%,100%{transform:scaleY(.15)}50%{transform:scaleY(1)}}
.lr-a-go{animation:lr-go 4s linear infinite}.lr-a-slow{animation-duration:3.6s;animation-timing-function:ease-in-out}.lr-a-d2{animation-delay:-2s}
.lr-a-sway{animation:lr-sway 5s ease-in-out infinite}
.lr-a-hl{animation:lr-hl 4.5s infinite}.lr-a-d15{animation-delay:1.5s}.lr-a-d3{animation-delay:3s}
.lr-a-ripple{animation:lr-ripple 2.4s ease-out infinite}.lr-a-ping{animation:lr-ping 2.4s ease-out infinite}.lr-a-d12{animation-delay:1.2s}
.lr-a-climb{animation:lr-climb 5s ease-in-out infinite}
.lr-a-bar{animation:lr-bar 1s ease-in-out infinite}

/* second set of topics: card pictures */
@keyframes lr-flow{to{stroke-dashoffset:-28}}
@keyframes lr-lite{0%,45%,100%{opacity:1}50%,90%{opacity:.15}}
@keyframes lr-trail{0%{stroke-dashoffset:100}60%,100%{stroke-dashoffset:0}}
@keyframes lr-drift{0%,100%{transform:translateX(-8px)}50%{transform:translateX(10px)}}
@keyframes lr-pulse{0%,100%{opacity:.4}50%{opacity:1}}
@keyframes lr-codeA{0%,40%{opacity:1}50%,90%{opacity:0}100%{opacity:1}}
@keyframes lr-codeB{0%,40%{opacity:0}50%,90%{opacity:1}100%{opacity:0}}
.lr-a-flow{animation:lr-flow 1.6s linear infinite}
.lr-a-lite{animation:lr-lite 1.6s infinite}
.lr-a-trail{animation:lr-trail 4s ease-out infinite}
.lr-a-drift{animation:lr-drift 6s ease-in-out infinite}
.lr-a-pulse{animation:lr-pulse 1s ease-in-out infinite}
.lr-a-codeA{animation:lr-codeA 4s infinite}.lr-a-codeB{animation:lr-codeB 4s infinite}
/* second set of topics: widgets */
.lr-sel{display:flex;gap:8px;flex-wrap:wrap;margin:10px 0 0}
.lr-tok{font:700 .95rem var(--mono);border:1px solid var(--line2);background:#101a2e;border-radius:8px;padding:6px 10px;color:var(--lr-mid)}
.lr-tok[aria-pressed=true]{border-color:var(--amber);color:var(--amber);background:#1a1606}
.lr-res{list-style:none;margin:10px 0 0;padding:0;display:grid;gap:6px;max-height:320px;overflow:auto}
.lr-res li{display:grid;grid-template-columns:3.2em 4.2em 1fr;gap:10px;align-items:baseline;padding:6px 10px;background:var(--panel);border:1px solid var(--line);border-radius:8px;font-size:.92rem}
.lr-res b{font-family:var(--mono);color:var(--amber)}.lr-res i{font:normal .85rem var(--mono);color:var(--cyan)}
.lr-pre{display:flex;gap:6px;flex-wrap:wrap;margin:6px 0 0}.lr-pre span{font:.85rem var(--mono);padding:4px 8px;border:1px solid var(--line);border-radius:6px;color:var(--lr-mid)}.lr-pre b{color:var(--amber)}
.lr-chk{display:flex;gap:8px;align-items:center;font-size:.9rem;color:var(--lr-mid)}
/* hub extras */
.lr-extras{display:grid;grid-template-columns:2fr 1fr 1fr;gap:12px;margin:0 0 22px}
.lr-daily,.lr-link{border:1px solid var(--line2);border-radius:14px;background:var(--lr-card);padding:14px 16px}
.lr-daily h2{margin:0 0 6px;font-size:1rem}.lr-daily .lr-dq{margin:0 0 8px;color:var(--text);line-height:1.45}
.lr-daily .lr-opts button{display:block;width:100%;text-align:left}
.lr-link{display:grid;align-content:center;gap:4px;text-decoration:none;color:var(--text);transition:border-color .15s,transform .15s}
.lr-link:hover{border-color:var(--cyan);transform:translateY(-2px)}.lr-link b{font-size:1.05rem}.lr-link span{color:var(--lr-mid);font-size:.9rem}
.lr-search{width:100%;max-width:280px;padding:7px 12px;background:#0a1020;border:1px solid var(--line2);border-radius:999px;color:var(--text);font:inherit;font-size:.9rem}
.lr-none{color:var(--lr-mid);margin:10px 0 0}
.lr-lv{font-size:.75rem;color:var(--muted)}
.lr-rank{color:var(--amber);font-weight:600}
.lr-streak{margin-left:8px;color:var(--lr-mid);font-size:.85rem}
.lr-js .lr-nojsmsg{display:none}.lr-more-l{margin:22px 0 0}
/* glossary and test yourself */
.lr-gl{margin:16px 0 0}.lr-gl h2{margin:22px 0 6px;color:var(--amber);font:700 1.2rem var(--mono)}
.lr-gl dl{margin:0;display:grid;gap:8px}.lr-gl dt{font-weight:700;color:var(--text)}.lr-gl dd{margin:0 0 6px;color:var(--lr-mid);line-height:1.5;max-width:44em}
.lr-gl div[hidden],.lr-gl section[hidden]{display:none}
.lr-az{display:flex;gap:6px;flex-wrap:wrap;margin:12px 0 0}.lr-az a{min-width:2em;text-align:center;padding:4px 8px;border:1px solid var(--line2);border-radius:8px;text-decoration:none;color:var(--lr-mid);font:.85rem var(--mono)}
.lr-qz{max-width:640px;margin:18px 0 0}.lr-qz .lr-qn{color:var(--muted);font:.85rem var(--mono);margin:0 0 8px}
.lr-qz h2{margin:0 0 12px;font-size:1.25rem;line-height:1.35}
.lr-score{font-size:2rem;font-weight:700;margin:6px 0}
@media(max-width:860px){.lr-extras{grid-template-columns:1fr 1fr}.lr-daily{grid-column:1/-1}}
@media(max-width:620px){.lr-res li{grid-template-columns:2.8em 3.6em 1fr}.lr-search{max-width:none}}

@media(max-width:1000px){.lr-cards{grid-template-columns:repeat(3,minmax(0,1fr))}.lr-cards4{grid-template-columns:repeat(2,minmax(0,1fr))}}
@media(max-width:860px){
 .lr-hero{grid-template-columns:1fr}
 .lr-pb{display:flex;flex-direction:column;gap:14px}
 .lr-copy{display:contents}
 .lr-simple,.lr-detail{order:1}.lr-lab{order:2}.lr-fact{order:3;margin:0}.lr-quiz{order:4;margin:0}.lr-watch{order:5;margin:0}
}
@media(max-width:620px){
 .lr-cards{grid-template-columns:repeat(2,minmax(0,1fr))}
 .lr-art{height:78px}
 .lr-hold{grid-template-columns:1fr}.lr-stack{min-height:150px;border-left:0;border-top:1px dashed var(--line2)}.lr-stack .pl{right:70px}
 .lr-bubble{position:static;max-width:none;border-width:1px 0 0;border-radius:0}
 .lr-scene-note,.lr-runway-l{display:none}
 .lr-pn{grid-template-columns:1fr}.lr-pn a[rel=next]{text-align:left}
}
@media (prefers-reduced-motion:reduce){.lr-main *{animation:none!important;transition:none!important}}