/* ---------------------------------------------------------------------------
   labs-ui.css - shared shell for the per-topic lab index pages.
   Same design language as /labs.html so the directory and the topics match.
   The labs themselves are untouched; this only styles the pages that list them.
   --------------------------------------------------------------------------- */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
:root{
  --bg:#070b12; --bg2:#0c131e; --card:#111a27; --card2:#162132;
  --line:#1f2e42; --line2:#2b3f59;
  --ink:#e8f0fb; --mute:#90a4bf; --dim:#64788f;
  --accent:#36c3ff; --accent2:#7b5cff; --gold:#ffc53d; --green:#3ddc84; --pink:#ff4d8d;
  --radius:14px;
  --font:"Inter",system-ui,-apple-system,"Segoe UI",Roboto,sans-serif;
  --mono:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body{background:var(--bg);color:var(--ink);font-family:var(--font);font-size:15px;line-height:1.6;
  background-image:radial-gradient(1200px 600px at 15% -10%,rgba(54,195,255,.10),transparent 60%),
                   radial-gradient(900px 500px at 90% 0%,rgba(123,92,255,.10),transparent 55%)}
a{color:var(--accent);text-decoration:none}
a:hover{text-decoration:underline}
:focus-visible{outline:2px solid var(--accent);outline-offset:3px;border-radius:6px}
.wrap{max-width:1180px;margin:0 auto;padding:0 20px}

/* top bar */
.topbar{position:sticky;top:0;z-index:50;backdrop-filter:blur(12px);background:rgba(7,11,18,.82);border-bottom:1px solid var(--line)}
.topbar .wrap{display:flex;align-items:center;gap:16px;padding-block:12px;flex-wrap:wrap}
.brand{display:flex;align-items:center;gap:10px;font-weight:700;letter-spacing:-.01em;color:var(--ink)}
.brand:hover{text-decoration:none}
.brand .dot{width:9px;height:9px;border-radius:50%;background:var(--accent);box-shadow:0 0 12px var(--accent)}
.topbar nav{margin-left:auto;display:flex;gap:18px;font-size:14px;color:var(--mute);flex-wrap:wrap}
.topbar nav a{color:var(--mute)}
.topbar nav a:hover{color:var(--ink);text-decoration:none}

/* hero */
header.hero{padding:40px 0 10px}
header.hero .eyebrow{font-size:12.5px;letter-spacing:.11em;text-transform:uppercase;color:var(--dim);font-weight:650;margin-bottom:9px}
header.hero .eyebrow a{color:var(--dim)}
header.hero h1{font-size:clamp(28px,4.4vw,44px);line-height:1.08;letter-spacing:-.025em;font-weight:760;display:flex;align-items:center;gap:14px;flex-wrap:wrap}
header.hero h1 .ico{font-size:.9em}
header.hero .sub{color:var(--mute);font-size:16px;max-width:76ch;margin-top:12px}
.stats{display:flex;gap:9px;flex-wrap:wrap;margin-top:18px}
.stat{border:1px solid var(--line);background:var(--card);border-radius:999px;padding:6px 14px;font-size:13px;color:var(--mute)}
.stat b{color:var(--ink);font-weight:700}

/* search */
.filterbar{display:flex;gap:10px;align-items:center;margin:22px 0 4px;flex-wrap:wrap}
.filterbar input{flex:1;min-width:240px;background:var(--bg2);border:1px solid var(--line2);border-radius:12px;
  color:var(--ink);font:inherit;padding:12px 15px}
.filterbar input::placeholder{color:var(--dim)}
.filterbar input:focus{outline:none;border-color:var(--accent);box-shadow:0 0 0 3px rgba(54,195,255,.14)}
.filterbar .count{color:var(--dim);font-size:13px;white-space:nowrap}

/* teach box */
details.teach{margin:20px 0 6px;border:1px solid var(--line);border-left:3px solid var(--gold);border-radius:12px;
  background:linear-gradient(180deg,rgba(255,197,61,.05),transparent 60%)}
details.teach>summary{cursor:pointer;list-style:none;padding:13px 18px;display:flex;align-items:center;gap:10px;font-weight:650;font-size:14.5px;color:var(--gold)}
details.teach>summary::-webkit-details-marker{display:none}
details.teach>summary::after{content:"\25be";margin-left:auto;color:var(--dim);transition:.2s}
details.teach[open]>summary::after{transform:rotate(180deg)}
.teach-body{padding:0 18px 18px;display:grid;gap:14px}
.teach-body h4{font-size:12px;letter-spacing:.09em;text-transform:uppercase;color:var(--dim);margin-bottom:5px;font-weight:650}
.teach-body p{opacity:.92;max-width:78ch}
.teach-body ol{margin:0;padding-left:20px;display:grid;gap:7px;color:var(--mute);max-width:78ch}
.teach-body ol li::marker{color:var(--gold);font-weight:700}
.learn{display:flex;gap:9px;flex-wrap:wrap;padding-top:4px}
.learn a{display:inline-flex;align-items:center;gap:8px;border-radius:10px;padding:9px 14px;font-size:13.5px;font-weight:600;
  border:1px solid var(--line2);background:var(--card);color:var(--ink)}
.learn a:hover{text-decoration:none;border-color:var(--accent);transform:translateY(-1px)}
.learn a.yt{border-color:rgba(255,77,141,.45);color:#ffd0e0}
.learn a.med{border-color:rgba(61,220,132,.45);color:#c4f5d9}
.learn a.course{border-color:rgba(255,197,61,.45);color:#ffe9b0}
.learn.refs a{font-weight:500;font-size:13px;color:var(--mute);background:transparent}
.learn.refs a:hover{color:var(--ink)}
.learn.refs a::before{content:"\2197";margin-right:2px;color:var(--dim)}

/* sections */
section.group{margin-top:34px}
section.group>h2{font-size:19px;letter-spacing:-.01em;display:flex;align-items:center;gap:10px;flex-wrap:wrap}
section.group>h2 .n{font-size:12px;font-weight:650;color:var(--dim);letter-spacing:.06em;text-transform:uppercase}
section.group>p.note{color:var(--mute);font-size:14px;margin-top:5px;max-width:80ch}

/* cards */
.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(270px,1fr));gap:13px;margin-top:14px}
.lab{position:relative;background:var(--card);border:1px solid var(--line);border-radius:var(--radius);
  padding:15px 16px 13px;display:flex;flex-direction:column;gap:8px;transition:.16s;overflow:hidden}
.lab::before{content:"";position:absolute;inset:0 auto 0 0;width:3px;background:linear-gradient(180deg,var(--accent),var(--accent2));opacity:0;transition:.16s}
.lab:hover{border-color:var(--line2);background:var(--card2);transform:translateY(-2px)}
.lab:hover::before{opacity:1}
.lab h3{font-size:15.5px;letter-spacing:-.01em;font-weight:680;line-height:1.3}
.lab h3 a{color:var(--ink)}
.lab h3 a:hover{text-decoration:none;color:var(--accent)}
.lab h3 a::after{content:"";position:absolute;inset:0}
.lab p{color:var(--mute);font-size:13.5px;line-height:1.5;flex:1}
.badges{display:flex;gap:6px;flex-wrap:wrap;align-items:center}
.badge{font-size:10.5px;font-weight:700;letter-spacing:.06em;text-transform:uppercase;border-radius:999px;padding:2px 8px;border:1px solid}
.badge.kind{color:var(--dim);border-color:var(--line2);background:transparent;font-weight:600;letter-spacing:.04em}
.badge.start{color:var(--green);border-color:rgba(61,220,132,.5);background:rgba(61,220,132,.1)}
.badge.new{color:var(--pink);border-color:rgba(255,77,141,.5);background:rgba(255,77,141,.1)}
.badge.hard{color:var(--gold);border-color:rgba(255,197,61,.5);background:rgba(255,197,61,.1)}
.badge.ext{color:var(--accent2);border-color:rgba(123,92,255,.5);background:rgba(123,92,255,.1)}

/* compact numbered labs */
.chips{display:flex;flex-wrap:wrap;gap:8px;margin-top:14px}
a.chiplab{position:relative;display:inline-flex;align-items:baseline;gap:7px;border:1px solid var(--line);background:var(--card);
  border-radius:11px;padding:9px 13px;color:var(--ink);font-weight:650;font-size:14px;transition:.14s}
a.chiplab .num{font-family:var(--mono);color:var(--accent);font-size:13px}
a.chiplab .tier{font-size:11px;color:var(--dim);font-weight:500}
a.chiplab:hover{text-decoration:none;border-color:var(--accent);background:var(--card2);transform:translateY(-1px)}

/* extras */
.extras{display:flex;gap:9px;flex-wrap:wrap;margin-top:14px}
.extras a{border:1px dashed var(--line2);border-radius:10px;padding:8px 13px;font-size:13.5px;color:var(--mute);background:transparent}
.extras a:hover{text-decoration:none;color:var(--ink);border-color:var(--accent)}

.empty{display:none;text-align:center;padding:50px 20px;color:var(--mute)}
.empty b{display:block;font-size:18px;color:var(--ink);margin-bottom:6px}

footer.pagefoot{border-top:1px solid var(--line);margin-top:50px}
footer.pagefoot .wrap{padding:26px 20px 70px;color:var(--dim);font-size:13.5px;display:flex;gap:14px 28px;flex-wrap:wrap;justify-content:space-between}

@media (max-width:640px){
  header.hero{padding-top:28px}
  .grid{grid-template-columns:1fr}
}
@media (prefers-reduced-motion:reduce){*{transition:none!important;scroll-behavior:auto}}