/* =========================================================
   MENG 4450 — PLC & Robotics
   In-class activity site. Shared styles.
   Brand: Mecharithm indigo #383890 + gold #F0C040, black & white.
   Palette and type are unchanged from the previous course site.
   ========================================================= */

:root{
  --font-display:-apple-system,BlinkMacSystemFont,"SF Pro Display","Inter","Helvetica Neue",Helvetica,Arial,sans-serif;
  --font-sans:-apple-system,BlinkMacSystemFont,"SF Pro Text","Inter","Helvetica Neue",Helvetica,Arial,sans-serif;
  --font-label:var(--font-sans);
  --font-mono:ui-monospace,SFMono-Regular,"SF Mono",Menlo,Monaco,Consolas,"Liberation Mono",monospace;

  --brand:#383890;
  --brand-deep:#2A2A6E;
  --brand-tint:#ECECF7;
  --gold:#F0C040;
  --gold-deep:#E0AE1E;
  --ink:#141414;
  --ink-soft:#565663;
  --ink-faint:#8A8A97;
  --paper:#FFFFFF;
  --paper-2:#F7F7FB;
  --line:#E6E6EC;
  --panel:#141414;

  /* semantic only: correctness must never rest on hue alone,
     so every use is paired with a glyph and a word */
  --yes:#1E7A5A;
  --yes-tint:#E7F4EF;
  --no:#A93226;
  --no-tint:#FBECEA;

  --maxw:1140px;
  --maxw-read:1000px;
}

*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;background:var(--paper);color:var(--ink);
  font-family:var(--font-sans);
  font-size:18px;line-height:1.65;-webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}
a{color:var(--brand);text-decoration:none}
a:hover{text-decoration:underline}
.wrap{max-width:var(--maxw);margin:0 auto;padding:0 28px}
.wrap.read{max-width:var(--maxw-read)}
:focus-visible{outline:3px solid var(--gold);outline-offset:3px}
@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}}

/* ---------- top bar ---------- */
.topbar{background:var(--brand);border-bottom:4px solid var(--gold)}
.topbar .wrap{display:flex;align-items:center;justify-content:space-between;padding:16px 28px;gap:18px}
.topbar a.brand{color:#fff;text-decoration:none;font-family:var(--font-label);font-weight:600;font-size:15px;letter-spacing:.06em}
.topbar a.brand:hover{color:#fff;text-decoration:none}
.topbar a.brand b{color:var(--gold)}
.topbar .tabs{display:flex;gap:22px;align-items:center}
.topbar .tab{color:#C9C9E8;text-decoration:none;font-family:var(--font-label);font-size:14px;letter-spacing:.04em}
.topbar .tab:hover{color:#fff;text-decoration:none}
.topbar .tab.on{color:#fff;box-shadow:inset 0 -2px 0 var(--gold)}
@media (max-width:560px){ .topbar .tabs{gap:14px} .topbar .tab{font-size:12.5px} }

/* ---------- hero ---------- */
.hero{background:var(--brand);color:#F4F4FA;border-bottom:5px solid var(--gold);overflow:hidden}
.hero .wrap{padding-top:70px;padding-bottom:62px}
.hero .wrap.hero-flex{display:flex;gap:48px;align-items:center;flex-wrap:wrap;justify-content:space-between}
.hero-copy{flex:0 1 560px;min-width:0}
.hero-art{flex:0 1 440px;min-width:280px}
.hero-art img{width:100%;height:auto;display:block;border-radius:16px;box-shadow:0 24px 60px rgba(0,0,0,.30);border:1px solid rgba(255,255,255,.18)}
@media (max-width:900px){ .hero-art{flex-basis:100%;max-width:520px} }
.hero .eyebrow{
  font-family:var(--font-label);font-size:15px;font-weight:500;letter-spacing:.08em;
  text-transform:uppercase;color:#C9C9E8;position:relative;padding-left:32px;margin:0;
}
.hero .eyebrow::before{content:"";position:absolute;left:0;top:50%;width:20px;height:2px;background:var(--gold)}
.hero h1{
  font-family:var(--font-display);font-weight:600;
  font-size:clamp(2.6rem,7vw,5.2rem);line-height:1.0;letter-spacing:-.03em;
  color:#fff;margin:.26em 0 .3em;
}
.hero h1 .amp{color:var(--gold)}
.hero .lede{max-width:52ch;color:#DEDEF0;font-size:clamp(1.02rem,1.9vw,1.22rem);line-height:1.6;margin:0}

@keyframes rise{from{opacity:0;transform:translateY(18px)}to{opacity:1;transform:none}}
.rise{opacity:0;animation:rise .7s cubic-bezier(.2,.7,.2,1) forwards}
.d1{animation-delay:.05s}.d2{animation-delay:.16s}.d3{animation-delay:.27s}.d4{animation-delay:.4s}
@media (prefers-reduced-motion:reduce){.rise{opacity:1;animation:none}}

/* ---------- breadcrumb ---------- */
.crumb{border-bottom:1px solid var(--line);background:var(--paper-2)}
.crumb .wrap{padding:14px 28px;font-family:var(--font-label);font-size:13px;letter-spacing:.03em;color:var(--ink-faint)}
.crumb a{color:var(--ink-soft)}
.crumb .sep{margin:0 8px}
.crumb .here{color:var(--ink)}

/* ---------- page header ---------- */
.page-head{padding:48px 0 6px}
.page-head .eyebrow{font-family:var(--font-label);font-size:14px;font-weight:500;letter-spacing:.075em;text-transform:uppercase;color:var(--brand)}
.page-head h1{font-family:var(--font-display);font-weight:600;font-size:clamp(2rem,5.4vw,3.2rem);line-height:1.06;letter-spacing:-.02em;margin:.22em 0 .26em}
.page-head .sub{font-size:clamp(1.04rem,2.2vw,1.24rem);color:var(--ink-soft);max-width:60ch;margin:0}

/* ---------- section ---------- */
.section{padding:44px 0 8px}
.section-head{display:flex;align-items:baseline;gap:18px;border-bottom:2px solid var(--brand);padding-bottom:12px;margin-bottom:26px;flex-wrap:wrap}
.section-head .eyebrow{font-family:var(--font-label);font-size:14px;font-weight:500;letter-spacing:.07em;text-transform:uppercase;color:var(--brand)}
.section-head h2{font-family:var(--font-display);font-weight:600;font-size:clamp(1.45rem,3.2vw,2rem);letter-spacing:-.015em;margin:0;line-height:1}

/* ---------- cards ---------- */
.grid{display:grid;grid-template-columns:repeat(2,1fr);gap:18px}
.grid.three{grid-template-columns:repeat(3,1fr)}
@media (max-width:860px){ .grid.three{grid-template-columns:repeat(2,1fr)} }
@media (max-width:720px){ .grid,.grid.three{grid-template-columns:1fr} }

.card{
  position:relative;display:block;text-decoration:none;color:inherit;background:var(--paper);
  border:1px solid var(--line);border-radius:4px;padding:26px;
  transition:border-color .2s ease, transform .2s ease, box-shadow .2s ease;
}
a.card:hover,a.card:focus-visible{border-color:var(--brand);transform:translateY(-3px);box-shadow:0 12px 30px rgba(56,56,144,.15);outline:none;text-decoration:none}
.card .kind{font-family:var(--font-label);font-size:12px;font-weight:500;letter-spacing:.07em;text-transform:uppercase;color:var(--ink-faint);display:flex;align-items:center;gap:8px;flex-wrap:wrap}
.card h3{font-family:var(--font-display);font-weight:600;font-size:1.28rem;margin:10px 0 8px;letter-spacing:-.01em;line-height:1.2}
.card p{margin:0;color:var(--ink-soft);font-size:.98rem;line-height:1.5}
.card .go{margin-top:16px;font-family:var(--font-label);font-size:14px;font-weight:500;color:var(--brand);letter-spacing:.03em}
.card.soon{background:var(--paper-2);border-style:dashed}
.card.soon h3{color:var(--ink-soft)}

/* ---------- flags ---------- */
.flags{display:flex;flex-wrap:wrap;gap:8px;margin-top:18px}
.flag{font-family:var(--font-label);font-size:12px;font-weight:600;letter-spacing:.06em;text-transform:uppercase;border-radius:999px;padding:5px 12px;white-space:nowrap;display:inline-block}
.flag.live{background:var(--gold);color:#3A2E04;border:1px solid var(--gold-deep)}
.flag.plan{background:var(--paper-2);color:var(--ink-soft);border:1px solid var(--line)}
.flag.mod{background:var(--brand);color:#fff;border:1px solid var(--brand)}
.flag.when{background:var(--brand-tint);color:var(--brand-deep);border:1px solid #D6D6EC;font-weight:500;text-transform:none;letter-spacing:.02em}
.card .kind .flag{font-size:10.5px;padding:3px 9px}

/* =========================================================
   ACTIVITY RUNNER
   Shared machinery for every in-class interactive.
   ========================================================= */

.stage{max-width:840px;margin:0 auto;padding:0 28px 20px}

/* round bar: progress dots + score */
.roundbar{
  display:flex;align-items:center;justify-content:space-between;gap:18px;flex-wrap:wrap;
  margin:30px 0 6px;padding:14px 18px;background:var(--paper-2);
  border:1px solid var(--line);border-radius:6px;
}
.roundbar .rname{font-family:var(--font-label);font-size:13px;font-weight:600;letter-spacing:.07em;text-transform:uppercase;color:var(--brand)}
.dots{display:flex;gap:7px;align-items:center}
.dots i{width:10px;height:10px;border-radius:50%;background:var(--line);display:block;transition:background .25s ease,transform .25s ease}
.dots i.done{background:var(--brand)}
.dots i.now{background:var(--gold);transform:scale(1.35)}
.score{font-family:var(--font-label);font-size:14px;color:var(--ink-soft)}
.score b{color:var(--ink);font-weight:600;font-variant-numeric:tabular-nums}

/* the card itself */
.play{
  background:var(--paper);border:1px solid var(--line);border-radius:10px;
  padding:32px 30px;margin-top:16px;box-shadow:0 10px 34px rgba(20,20,20,.06);
}
.play .prompt{font-family:var(--font-label);font-size:13px;font-weight:600;letter-spacing:.07em;text-transform:uppercase;color:var(--ink-faint);margin:0 0 12px}
.play h2{font-family:var(--font-display);font-weight:600;font-size:clamp(1.3rem,3vw,1.75rem);line-height:1.25;letter-spacing:-.015em;margin:0 0 4px}
.play .setup{color:var(--ink-soft);font-size:1.02rem;margin:10px 0 0}

/* option buttons */
.opts{display:flex;flex-direction:column;gap:10px;margin-top:24px}
.opt{
  width:100%;text-align:left;font:inherit;font-size:1rem;color:var(--ink);
  background:var(--paper);border:1.5px solid var(--line);border-radius:8px;
  padding:15px 18px;cursor:pointer;display:flex;gap:13px;align-items:flex-start;
  transition:border-color .16s ease,background .16s ease,transform .12s ease;
}
.opt:hover:not(:disabled){border-color:var(--brand);background:var(--brand-tint)}
.opt:active:not(:disabled){transform:scale(.995)}
.opt .mark{
  flex:0 0 auto;width:24px;height:24px;border-radius:50%;border:1.5px solid var(--line);
  display:grid;place-items:center;font-size:13px;font-weight:700;color:transparent;margin-top:1px;
}
.opt.picked{border-color:var(--brand)}
.opt.right{border-color:var(--yes);background:var(--yes-tint)}
.opt.right .mark{background:var(--yes);border-color:var(--yes);color:#fff}
.opt.wrong{border-color:var(--no);background:var(--no-tint)}
.opt.wrong .mark{background:var(--no);border-color:var(--no);color:#fff}
.opt:disabled{cursor:default;opacity:.96}

/* two-bin choice (bigger, side by side) */
.bins{display:grid;grid-template-columns:1fr 1fr;gap:14px;margin-top:24px}
@media (max-width:560px){ .bins{grid-template-columns:1fr} }
.bin{
  font:inherit;cursor:pointer;text-align:center;padding:22px 18px;border-radius:10px;
  border:1.5px solid var(--line);background:var(--paper);color:var(--ink);
  transition:border-color .16s ease,background .16s ease,transform .12s ease;
}
.bin:hover:not(:disabled){border-color:var(--brand);background:var(--brand-tint)}
.bin:active:not(:disabled){transform:scale(.99)}
.bin b{display:block;font-family:var(--font-display);font-size:1.12rem;font-weight:600;margin-bottom:4px}
.bin span{display:block;font-size:.9rem;color:var(--ink-soft);line-height:1.45}
.bin.right{border-color:var(--yes);background:var(--yes-tint)}
.bin.wrong{border-color:var(--no);background:var(--no-tint)}
.bin:disabled{cursor:default}

/* weight-placement puzzle */
.tray{display:flex;flex-wrap:wrap;gap:10px;margin:22px 0 6px;padding:16px;background:var(--paper-2);border:1px dashed var(--line);border-radius:8px;min-height:74px;align-items:center}
.tray .hint{font-family:var(--font-label);font-size:13px;color:var(--ink-faint);margin-right:4px}
.chip{
  font:inherit;font-family:var(--font-label);font-weight:600;font-size:1.05rem;cursor:pointer;
  background:var(--gold);color:#3A2E04;border:1.5px solid var(--gold-deep);
  border-radius:999px;padding:9px 20px;font-variant-numeric:tabular-nums;
  transition:transform .12s ease,box-shadow .16s ease;
}
.chip:hover:not(:disabled){transform:translateY(-2px);box-shadow:0 6px 16px rgba(240,192,64,.5)}
.chip.sel{box-shadow:0 0 0 4px rgba(56,56,144,.28);transform:translateY(-2px)}
.chip:disabled{opacity:.45;cursor:default;transform:none;box-shadow:none}

.rows{list-style:none;margin:14px 0 0;padding:0;border-top:1px solid var(--line)}
.rows li{display:flex;align-items:center;gap:16px;padding:14px 0;border-bottom:1px solid var(--line)}
.rows .lbl{flex:1 1 auto;font-size:1rem;line-height:1.4}
.rows .lbl small{display:block;color:var(--ink-faint);font-size:.86rem;margin-top:2px}
.slot{
  flex:0 0 auto;min-width:92px;height:46px;border-radius:8px;font:inherit;cursor:pointer;
  border:1.5px dashed var(--line);background:var(--paper-2);color:var(--ink-faint);
  font-family:var(--font-label);font-weight:600;font-size:1rem;font-variant-numeric:tabular-nums;
  display:grid;place-items:center;transition:border-color .16s ease,background .16s ease;
}
.slot:hover:not(:disabled){border-color:var(--brand)}
.slot.filled{border-style:solid;border-color:var(--gold-deep);background:var(--gold);color:#3A2E04}
.slot.right{border-style:solid;border-color:var(--yes);background:var(--yes-tint);color:var(--yes)}
.slot.wrong{border-style:solid;border-color:var(--no);background:var(--no-tint);color:var(--no)}
.slot:disabled{cursor:default}

/* reveal / feedback panel */
.reveal{
  margin-top:22px;padding:20px 22px;border-radius:8px;
  background:var(--brand-tint);border-left:4px solid var(--gold);
  animation:rise .32s cubic-bezier(.2,.7,.2,1) both;
}
.reveal .verdict{font-family:var(--font-label);font-size:13px;font-weight:700;letter-spacing:.07em;text-transform:uppercase;margin:0 0 8px;display:flex;align-items:center;gap:8px}
.reveal .verdict.y{color:var(--yes)}
.reveal .verdict.n{color:var(--no)}
.reveal p{margin:0 0 10px;font-size:1rem;line-height:1.6;color:var(--ink)}
.reveal p:last-child{margin-bottom:0}
.reveal .quote{
  margin:12px 0 0;padding:12px 16px;background:#fff;border:1px solid #D6D6EC;border-radius:6px;
  font-size:.95rem;color:var(--ink-soft);line-height:1.55;
}
.reveal .quote b{display:block;font-family:var(--font-label);font-size:11.5px;font-weight:600;letter-spacing:.07em;text-transform:uppercase;color:var(--brand);margin-bottom:5px}

/* controls */
.controls{display:flex;gap:12px;margin-top:24px;flex-wrap:wrap}
.btn{
  font:inherit;font-family:var(--font-label);font-weight:600;font-size:1rem;cursor:pointer;
  border-radius:8px;padding:14px 26px;border:1.5px solid var(--brand);
  background:var(--brand);color:#fff;transition:background .16s ease,transform .12s ease,box-shadow .16s ease;
}
.btn:hover:not(:disabled){background:var(--brand-deep);box-shadow:0 10px 24px rgba(56,56,144,.26)}
.btn:active:not(:disabled){transform:translateY(1px)}
.btn.gold{background:var(--gold);border-color:var(--gold);color:var(--ink)}
.btn.gold:hover:not(:disabled){background:var(--gold-deep);border-color:var(--gold-deep);box-shadow:0 10px 24px rgba(240,192,64,.5)}
.btn.ghost{background:transparent;color:var(--brand)}
.btn.ghost:hover:not(:disabled){background:var(--brand-tint);box-shadow:none}
.btn:disabled{opacity:.4;cursor:default;box-shadow:none}
.btn.wide{flex:1 1 220px}

/* scoreboard / end screen */
.final{text-align:center;padding:8px 0 4px}
.final .big{font-family:var(--font-display);font-weight:600;font-size:clamp(3rem,12vw,5.5rem);line-height:1;letter-spacing:-.03em;color:var(--brand);font-variant-numeric:tabular-nums}
.final .of{font-family:var(--font-label);font-size:15px;letter-spacing:.07em;text-transform:uppercase;color:var(--ink-faint);margin-top:6px}
.final .verdictline{font-size:1.1rem;color:var(--ink-soft);max-width:52ch;margin:18px auto 0}

/* summary table */
.tbl{width:100%;border-collapse:collapse;margin-top:20px;font-size:.96rem}
.tbl th,.tbl td{text-align:left;padding:11px 12px;border-bottom:1px solid var(--line);vertical-align:top}
.tbl th{font-family:var(--font-label);font-size:12px;font-weight:600;letter-spacing:.06em;text-transform:uppercase;color:var(--brand);background:var(--paper-2)}
.tbl td.w{font-variant-numeric:tabular-nums;font-weight:600;white-space:nowrap}
.tbl tr:last-child td{border-bottom:none}
.tbl .tot td{background:var(--brand-tint);font-weight:600;color:var(--brand-deep)}

/* mascot cartoons */
.toon{width:132px;margin:0 auto 4px;display:block}
.toon svg{width:100%;height:auto;display:block}
.toon.side{width:96px;margin:0}
.play .head-toon{display:flex;justify-content:center;margin:0 0 10px}
.reveal .rev-head{display:flex;align-items:flex-start;gap:14px}
.reveal .rev-head .toon{flex:0 0 76px;width:76px;margin:2px 0 0}
.reveal .rev-body{flex:1 1 auto;min-width:0}
@keyframes bob{0%,100%{transform:translateY(0)}50%{transform:translateY(-5px)}}
.toon.bob{animation:bob 2.6s ease-in-out infinite}
@media (prefers-reduced-motion:reduce){.toon.bob{animation:none}}

/* true/false bins */
.bins.tf .bin b{font-size:1.35rem;letter-spacing:.02em}

/* instructor note */
.teach{
  margin:36px 0 0;padding:20px 22px;border:1px solid var(--line);border-left:4px solid var(--brand);
  border-radius:4px;background:var(--paper-2);
}
.teach h4{font-family:var(--font-label);font-size:12px;font-weight:700;letter-spacing:.08em;text-transform:uppercase;color:var(--brand);margin:0 0 10px}
.teach p{margin:0 0 8px;font-size:.96rem;color:var(--ink-soft);line-height:1.6}
.teach p:last-child{margin-bottom:0}
.teach ul{margin:0;padding-left:20px;color:var(--ink-soft);font-size:.96rem;line-height:1.6}

/* ---------- footer ---------- */
footer{margin-top:76px;background:var(--brand);color:#C9C9E8;border-top:4px solid var(--gold)}
footer .wrap{padding:34px 28px 20px;display:flex;justify-content:space-between;flex-wrap:wrap;gap:16px;align-items:center}
footer .fmono{font-family:var(--font-label);font-size:15px;letter-spacing:.05em}
footer .fmono b{color:var(--gold);font-weight:600}
footer .lab{display:flex;align-items:center;gap:16px;text-decoration:none}
footer .lab:hover{text-decoration:none}
footer .labchip{background:#fff;border-radius:12px;padding:6px;display:inline-flex;line-height:0;box-shadow:0 6px 16px rgba(0,0,0,.18)}
footer .labchip img{height:56px;width:auto;display:block}
footer .labtxt{font-family:var(--font-label);font-size:13px;line-height:1.55;color:#C9C9E8}
footer .labtxt b{color:#fff;font-weight:600}
footer .labtxt .u{color:var(--gold)}
footer .lab:hover .labtxt .u{text-decoration:underline}
footer .copyline{max-width:var(--maxw);margin:0 auto;padding:18px 28px 32px;border-top:1px solid rgba(255,255,255,.14);font-family:var(--font-label);font-size:12.5px;line-height:1.6;letter-spacing:.02em;color:#AEAED2}

/* print: an activity page should print as a clean handout */
@media print{
  .topbar,.crumb,footer,.controls,.roundbar{display:none}
  .play{box-shadow:none;border:1px solid #000}
  body{font-size:12pt}
}