/* ===========================================================================
   PharmLearn — design system + landing + learn app
   Light, professional chrome (Codecademy/DataCamp feel) + dark code editor.
   Self-contained: no web fonts, no CDN.
   =========================================================================== */
:root{
  --brand:#5b4be6; --brand-ink:#4338ca; --brand-soft:#eef0fe;
  --accent:#10b981; --accent-ink:#047857; --accent-soft:#e7f8f1;
  --sky:#0ea5e9; --amber:#f59e0b; --warn:#ef4444; --warn-soft:#fdecec;
  --bg:#ffffff; --soft:#f6f7fb; --soft2:#eceffa; --card:#ffffff;
  --border:#e5e8f2; --border-2:#d7dcec;
  --ink:#0f172a; --ink-2:#334155; --muted:#6b7793; --muted-2:#5a6580;
  --editor-bg:#0e1526; --editor-panel:#131c31; --editor-ink:#d7e2ff; --editor-line:#22304d;
  --shadow:0 1px 2px rgba(16,24,40,.04),0 8px 24px rgba(16,24,40,.06);
  --shadow-lg:0 24px 60px -12px rgba(45,42,120,.28);
  --r:14px; --r-sm:10px; --maxw:1180px;
  --sans:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;
  --mono:"SF Mono",ui-monospace,"JetBrains Mono",Menlo,Consolas,monospace;
}
*{box-sizing:border-box;}
html,body{margin:0;padding:0;}
body{font-family:var(--sans);color:var(--ink);background:var(--bg);line-height:1.6;-webkit-font-smoothing:antialiased;}
a{color:var(--brand-ink);text-decoration:none;}
h1,h2,h3,h4{line-height:1.15;letter-spacing:-.02em;margin:0;}
.muted{color:var(--muted);}
.mono{font-family:var(--mono);}
.wrap{max-width:var(--maxw);margin:0 auto;padding:0 24px;}

/* buttons */
.btn{display:inline-flex;align-items:center;gap:8px;font:inherit;font-weight:600;font-size:15px;
  border:1px solid transparent;border-radius:11px;padding:11px 20px;cursor:pointer;transition:.15s;white-space:nowrap;}
.btn.primary{background:var(--brand);color:#fff;box-shadow:0 6px 18px -6px rgba(91,75,230,.6);}
.btn.primary:hover{background:var(--brand-ink);transform:translateY(-1px);}
.btn.ghost{background:transparent;color:var(--ink-2);border-color:var(--border-2);}
.btn.ghost:hover{border-color:var(--brand);color:var(--brand-ink);}
.btn.lg{font-size:16px;padding:14px 26px;border-radius:12px;}
.btn.white{background:#fff;color:var(--brand-ink);}
.btn.white:hover{background:#f2f2ff;}

/* logo */
.logo{display:inline-flex;align-items:center;gap:10px;font-weight:800;font-size:20px;letter-spacing:-.03em;color:var(--ink);}
.logo .glyph{width:30px;height:30px;border-radius:9px;background:linear-gradient(135deg,var(--brand),var(--sky));
  display:grid;place-items:center;color:#fff;font-size:16px;box-shadow:0 4px 12px -3px rgba(91,75,230,.5);}
.logo .glyph::before{content:"⌁";font-weight:700;}
.logo b{color:var(--brand-ink);}

/* ============================ LANDING ============================ */
.nav{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.85);backdrop-filter:blur(12px);border-bottom:1px solid var(--border);}
.nav .wrap{display:flex;align-items:center;gap:24px;height:66px;}
.nav .links{margin-left:auto;display:flex;align-items:center;gap:26px;}
.nav .links a{color:var(--ink-2);font-weight:500;font-size:15px;}
.nav .links a:hover{color:var(--brand-ink);}

.hero{position:relative;overflow:hidden;background:
  radial-gradient(1200px 500px at 82% -8%,rgba(91,75,230,.10),transparent 60%),
  radial-gradient(900px 500px at 0% 0%,rgba(14,165,233,.08),transparent 55%);}
.hero .wrap{display:grid;grid-template-columns:1.05fr .95fr;gap:56px;align-items:center;padding:78px 24px 88px;}
.eyebrow{display:inline-flex;align-items:center;gap:8px;font-weight:700;font-size:12.5px;letter-spacing:.09em;
  text-transform:uppercase;color:var(--brand-ink);background:var(--brand-soft);padding:6px 12px;border-radius:100px;margin-bottom:20px;}
.hero h1{font-size:54px;font-weight:800;letter-spacing:-.035em;}
.hero h1 .grad{background:linear-gradient(115deg,var(--brand),var(--sky));-webkit-background-clip:text;background-clip:text;color:transparent;}
.hero p.lede{font-size:19px;color:var(--ink-2);margin:22px 0 30px;max-width:36ch;}
.hero .cta{display:flex;gap:14px;flex-wrap:wrap;align-items:center;}
.hero .trust{margin-top:26px;display:flex;gap:22px;flex-wrap:wrap;color:var(--muted);font-size:14px;}
.hero .trust b{color:var(--ink);}
.hero .trust .ck{color:var(--accent);font-weight:700;}

/* hero product mock */
.mock{background:var(--editor-bg);border-radius:16px;box-shadow:var(--shadow-lg);overflow:hidden;border:1px solid #1c2740;}
.mock .bar{display:flex;align-items:center;gap:7px;padding:12px 14px;background:#0b1120;border-bottom:1px solid #1c2740;}
.mock .bar i{width:11px;height:11px;border-radius:50%;display:inline-block;}
.mock .bar i:nth-child(1){background:#ff5f57;}.mock .bar i:nth-child(2){background:#febc2e;}.mock .bar i:nth-child(3){background:#28c840;}
.mock .bar span{margin-left:10px;color:#6b7ba3;font-size:12px;font-family:var(--mono);}
.mock pre{margin:0;padding:18px 20px;font-family:var(--mono);font-size:13px;line-height:1.65;color:var(--editor-ink);overflow-x:auto;}
.mock .rec{color:#c792ea;}.mock .kw{color:#c3e88d;}.mock .num{color:#f78c6c;}.mock .var{color:#82aaff;}.mock .cm{color:#5b6b8c;}
.mock .result{border-top:1px solid #1c2740;padding:14px 20px;background:#0b1120;display:flex;align-items:center;gap:10px;font-size:13.5px;}
.mock .result .ok{color:#34d399;font-weight:700;}
.mock .chk{display:block;color:#9fb0d4;font-size:12.5px;font-family:var(--mono);padding:2px 0;}
.mock .chk .y{color:#34d399;}

section.band{padding:84px 0;}
section.alt{background:var(--soft);}
.sec-head{text-align:center;max-width:620px;margin:0 auto 52px;}
.sec-head .eyebrow{margin-bottom:14px;}
.sec-head h2{font-size:37px;font-weight:800;letter-spacing:-.03em;}
.sec-head p{font-size:18px;color:var(--muted);margin-top:14px;}

.features{display:grid;grid-template-columns:repeat(4,1fr);gap:20px;}
.feat{background:var(--card);border:1px solid var(--border);border-radius:var(--r);padding:26px 22px;box-shadow:var(--shadow);transition:.18s;}
.feat:hover{transform:translateY(-3px);border-color:var(--border-2);box-shadow:var(--shadow-lg);}
.feat .ic{width:46px;height:46px;border-radius:12px;display:grid;place-items:center;font-size:22px;margin-bottom:16px;background:var(--brand-soft);}
.feat h3{font-size:18px;margin-bottom:8px;}
.feat p{font-size:14.5px;color:var(--muted);margin:0;}

.curric{display:grid;grid-template-columns:repeat(3,1fr);gap:18px;}
.mcard{background:var(--card);border:1px solid var(--border);border-radius:var(--r);padding:22px;box-shadow:var(--shadow);position:relative;overflow:hidden;text-decoration:none;color:inherit;display:block;transition:transform .15s,box-shadow .15s;}
a.mcard:hover{transform:translateY(-2px);box-shadow:0 10px 30px rgba(0,0,0,.10);}
.mcard .n{font-family:var(--mono);font-size:13px;font-weight:700;color:var(--brand);background:var(--brand-soft);width:34px;height:34px;border-radius:9px;display:grid;place-items:center;margin-bottom:14px;}
.mcard h3{font-size:17px;margin-bottom:6px;}
.mcard p{font-size:14px;color:var(--muted);margin:0 0 14px;}
.mcard .lc{font-size:12.5px;color:var(--muted-2);font-weight:600;display:flex;align-items:center;gap:6px;}
.mcard .lc::before{content:"●";color:var(--accent);}

.steps{display:grid;grid-template-columns:repeat(3,1fr);gap:34px;counter-reset:s;}
.step{text-align:center;}
.step .b{counter-increment:s;width:52px;height:52px;margin:0 auto 16px;border-radius:14px;background:linear-gradient(135deg,var(--brand),var(--sky));
  color:#fff;display:grid;place-items:center;font-weight:800;font-size:22px;box-shadow:0 10px 24px -8px rgba(91,75,230,.6);}
.step .b::before{content:counter(s);}
.step h3{font-size:18px;margin-bottom:8px;}
.step p{color:var(--muted);font-size:15px;margin:0;}

.cta-band{background:linear-gradient(120deg,var(--brand),#6d3ff0 55%,var(--sky));border-radius:24px;padding:56px;text-align:center;color:#fff;box-shadow:var(--shadow-lg);}
.cta-band h2{font-size:34px;font-weight:800;color:#fff;}
.cta-band p{font-size:18px;opacity:.92;margin:12px 0 26px;}

footer.foot{border-top:1px solid var(--border);padding:40px 0;color:var(--muted);font-size:14px;}
footer.foot .wrap{display:flex;align-items:center;gap:18px;flex-wrap:wrap;}
footer.foot .links{margin-left:auto;display:flex;gap:20px;}

/* ============================ LEARN APP ============================ */
body.app{height:100vh;overflow:hidden;display:flex;flex-direction:column;background:var(--soft);}
.appbar{display:flex;align-items:center;gap:18px;height:58px;padding:0 20px;background:var(--bg);border-bottom:1px solid var(--border);flex:0 0 auto;z-index:20;}
.appbar .logo{font-size:18px;}
.appbar .prog{margin-left:auto;display:flex;align-items:center;gap:12px;min-width:230px;}
.appbar .bar{flex:1;height:8px;background:var(--soft2);border-radius:8px;overflow:hidden;}
.appbar .bar i{display:block;height:100%;width:0;background:linear-gradient(90deg,var(--brand),var(--accent));transition:width .45s;}
.appbar .ptext{font-size:12.5px;color:var(--muted);font-weight:600;white-space:nowrap;}
.cert-link{cursor:pointer;font-size:12px;font-weight:700;padding:5px 11px;border-radius:100px;border:1px solid var(--accent);background:var(--accent-soft);color:var(--accent-ink);white-space:nowrap;}
:focus-visible{outline:2px solid var(--brand);outline-offset:2px;border-radius:4px;}
.pill{font-size:11.5px;font-weight:700;padding:4px 10px;border-radius:100px;background:var(--soft2);color:var(--muted);}
.pill.on{background:var(--accent-soft);color:var(--accent-ink);}
.pill .dot{color:var(--accent);}

.applayout{flex:1;display:flex;overflow:hidden;}

/* sidebar */
#sidebar{width:296px;flex:0 0 296px;background:var(--bg);border-right:1px solid var(--border);overflow-y:auto;padding:6px 0 40px;}
.mod-group{padding:6px 0;}
.mod-title{padding:16px 18px 3px;font-size:11px;font-weight:800;letter-spacing:.06em;text-transform:uppercase;color:var(--muted-2);}
.mod-title .mn{color:var(--brand);}
.mod-blurb{padding:0 18px 8px;font-size:11.5px;color:var(--muted-2);}
.lesson{display:flex;align-items:center;gap:11px;padding:9px 18px;cursor:pointer;font-size:13.5px;color:var(--ink-2);border-left:3px solid transparent;transition:.12s;}
.lesson:hover{background:var(--soft);}
.lesson.active{background:var(--brand-soft);border-left-color:var(--brand);color:var(--brand-ink);font-weight:600;}
.lesson .dot{width:18px;height:18px;flex:0 0 18px;border-radius:50%;border:2px solid var(--border-2);display:grid;place-items:center;font-size:10px;color:transparent;transition:.15s;}
.lesson.done .dot{background:var(--accent);border-color:var(--accent);color:#fff;}
.lesson.done .dot::after{content:"✓";}
.lesson .kind{margin-left:auto;font-size:10px;font-weight:700;letter-spacing:.04em;color:var(--muted-2);text-transform:uppercase;}
.lesson.active .kind{color:var(--brand);}

/* projects */
.proj-group{border-top:1px solid var(--border);margin-top:6px;}
.lesson .dot.proj{background:linear-gradient(135deg,var(--brand),var(--sky));border:none;color:#fff;font-size:8px;}
.crumb-link{cursor:pointer;color:var(--brand);}
.crumb-link:hover{text-decoration:underline;}
.psteps{list-style:none;padding:0;margin:12px 0 0;counter-reset:ps;}
.pstep{display:flex;align-items:center;gap:12px;padding:12px 14px;margin-bottom:8px;border:1px solid var(--border);
  border-radius:11px;cursor:pointer;font-weight:600;font-size:14px;transition:.14s;background:var(--bg);}
.pstep:hover{border-color:var(--brand);background:var(--brand-soft);}
.pstep .si{flex:0 0 26px;height:26px;border-radius:50%;background:var(--soft2);color:var(--muted);
  display:grid;place-items:center;font-size:13px;font-weight:700;}
.pstep.done{border-color:#cdeede;}
.pstep.done .si{background:var(--accent);color:#fff;}

/* content pane */
#content{width:42%;flex:0 0 42%;overflow-y:auto;padding:30px 34px 70px;background:var(--bg);border-right:1px solid var(--border);}
.crumb{font-size:11.5px;font-weight:700;letter-spacing:.05em;text-transform:uppercase;color:var(--brand);}
#lesson-meta h1{font-size:27px;font-weight:800;margin-top:4px;}
#concept{margin-top:18px;color:var(--ink-2);}
#concept h1,#concept h2,#concept h3{margin:22px 0 10px;color:var(--ink);}
#concept h1{font-size:23px;}
#concept h2{font-size:19px;}
#concept h3{font-size:16px;color:var(--ink-2);}
#concept p{margin:12px 0;}
#concept code{background:var(--soft2);color:var(--brand-ink);padding:1.5px 6px;border-radius:6px;font-family:var(--mono);font-size:12.5px;}
#concept pre{background:var(--editor-bg);border-radius:12px;padding:15px 17px;overflow-x:auto;border:1px solid var(--editor-line);}
#concept pre code{background:none;color:var(--editor-ink);padding:0;font-size:12.5px;line-height:1.6;}
#concept table{border-collapse:collapse;width:100%;margin:14px 0;font-size:13.5px;}
#concept th,#concept td{border:1px solid var(--border);padding:8px 11px;text-align:left;vertical-align:top;}
#concept th{background:var(--soft);font-weight:700;}
#concept ul{margin:12px 0;padding-left:20px;}
#concept li{margin:5px 0;}
#concept blockquote{border-left:3px solid var(--brand);background:var(--brand-soft);margin:14px 0;padding:10px 16px;border-radius:0 10px 10px 0;color:var(--ink-2);}
.task{margin-top:22px;background:linear-gradient(180deg,var(--accent-soft),#fff);border:1px solid #cdeede;border-radius:14px;padding:16px 18px;}
.task .th{font-weight:800;color:var(--accent-ink);font-size:13.5px;display:flex;align-items:center;gap:7px;margin-bottom:6px;}
.task .tb{color:var(--ink-2);font-size:14.5px;}
.task .tb code{background:#fff;border:1px solid #cdeede;color:var(--accent-ink);padding:1px 6px;border-radius:5px;font-family:var(--mono);font-size:12.5px;}

/* workbench */
#workbench{flex:1;display:flex;flex-direction:column;overflow:hidden;padding:16px 18px;min-width:0;}
.wb-head{display:flex;align-items:center;gap:12px;margin-bottom:10px;}
.ds-cap{font-size:12px;color:var(--muted);font-family:var(--mono);margin-bottom:8px;}
.ds-scroll{overflow-x:auto;max-width:100%;}
.ds-table{border-collapse:collapse;font-family:var(--mono);font-size:12px;white-space:nowrap;}
.ds-table th,.ds-table td{border:1px solid var(--line);padding:4px 9px;text-align:right;}
.ds-table th{background:var(--panel-2,rgba(127,127,127,.08));color:var(--ink);position:sticky;top:0;font-weight:700;}
.ds-table td{color:var(--ink-2,var(--muted));}
.wb-head .ds{font-size:12.5px;color:var(--muted);font-family:var(--mono);display:flex;align-items:center;gap:6px;}
.wb-head .ds::before{content:"⛃";color:var(--muted-2);}
.wb-head .actions{margin-left:auto;display:flex;gap:8px;}
.ebtn{font:inherit;font-size:13px;font-weight:600;border-radius:9px;padding:8px 14px;cursor:pointer;border:1px solid var(--border-2);background:#fff;color:var(--ink-2);transition:.14s;}
.ebtn:hover{border-color:var(--brand);color:var(--brand-ink);}
.ebtn.run{border-color:var(--border-2);}
.ebtn.check{background:var(--brand);border-color:var(--brand);color:#fff;box-shadow:0 5px 14px -5px rgba(91,75,230,.6);}
.ebtn.check:hover{background:var(--brand-ink);color:#fff;}
.ebtn:disabled{opacity:.55;cursor:default;}

/* dark code editor with syntax highlight overlay */
.editor{position:relative;flex:1;min-height:170px;border-radius:12px;overflow:hidden;border:1px solid var(--editor-line);background:var(--editor-bg);}
.editor.focus{border-color:var(--brand);box-shadow:0 0 0 3px rgba(91,75,230,.18);}
.editor pre,.editor textarea{margin:0;position:absolute;inset:0;padding:15px 16px;font-family:var(--mono);font-size:13.5px;line-height:1.55;
  tab-size:2;white-space:pre;overflow:auto;border:0;}
.editor pre{pointer-events:none;color:var(--editor-ink);}
.editor textarea{color:transparent;background:transparent;caret-color:#fff;resize:none;outline:none;}
.editor textarea::selection{background:rgba(91,75,230,.45);}
.tok-rec{color:#c792ea;font-weight:600;}
.tok-kw{color:#c3e88d;}
.tok-num{color:#f78c6c;}
.tok-var{color:#82aaff;}
.tok-cm{color:#7d8bad;font-style:italic;}

/* tabs + panels */
.tabs{display:flex;gap:3px;margin-top:12px;border-bottom:1px solid var(--border);}
.tab{font:inherit;font-size:13px;font-weight:600;border:0;background:none;color:var(--muted);padding:9px 15px;cursor:pointer;border-bottom:2px solid transparent;margin-bottom:-1px;}
.tab.active{color:var(--brand-ink);border-bottom-color:var(--brand);}
.tab .badge{margin-left:6px;font-size:10px;background:var(--soft2);color:var(--muted);padding:1px 6px;border-radius:8px;}
.panel{display:none;flex:0 0 33%;height:33%;overflow-y:auto;background:var(--bg);border:1px solid var(--border);border-top:0;border-radius:0 0 12px 12px;padding:14px 16px;}
.panel.active{display:block;}
.panel .empty{color:var(--muted);font-size:13.5px;}
.panel pre{background:var(--editor-bg);color:var(--editor-ink);border-radius:10px;padding:12px;overflow-x:auto;font-size:12px;font-family:var(--mono);margin:8px 0 0;}

.verdict{font-weight:700;font-size:14px;padding:10px 14px;border-radius:10px;margin-bottom:10px;display:flex;align-items:center;gap:8px;}
.verdict.pass{background:var(--accent-soft);color:var(--accent-ink);}
.verdict.fail{background:var(--warn-soft);color:#b42318;}
.verdict.neutral{background:var(--soft);color:var(--ink-2);}
.check-item{display:flex;gap:10px;padding:8px 0;border-bottom:1px solid var(--border);align-items:flex-start;font-size:13.5px;}
.check-item:last-child{border-bottom:0;}
.check-item .mk{flex:0 0 20px;height:20px;border-radius:50%;display:grid;place-items:center;font-size:11px;font-weight:800;color:#fff;}
.check-item.pass .mk{background:var(--accent);}
.check-item.fail .mk{background:var(--warn);}
.check-item .lbl code{background:var(--soft2);padding:1px 5px;border-radius:5px;font-family:var(--mono);font-size:12px;}
.check-item .detail{display:block;color:var(--muted);font-size:12px;margin-top:2px;}
.coaching{margin-top:14px;padding:12px 14px;background:var(--brand-soft);border-radius:11px;border-left:3px solid var(--brand);font-size:13.5px;color:var(--ink-2);white-space:pre-wrap;}
.coaching .ai-tag{display:inline-block;font-size:10px;font-weight:700;letter-spacing:.05em;text-transform:uppercase;color:var(--brand);margin-bottom:5px;}
.fail-help{display:flex;gap:8px;flex-wrap:wrap;margin-top:14px;}
.help-btn{cursor:pointer;font-size:12.5px;}
.hint-list{margin:12px 0 0;padding-left:20px;display:flex;flex-direction:column;gap:8px;}
.hint-list li{font-size:13px;color:var(--ink-2);line-height:1.5;}
.hint-list li code{background:var(--soft2);padding:1px 5px;border-radius:5px;font-family:var(--mono);font-size:12px;}

/* tutor */
#panel-tutor.active{display:flex;flex-direction:column;}
#chat{flex:1;overflow-y:auto;display:flex;flex-direction:column;gap:9px;padding-bottom:6px;}
#chat .hi{color:var(--muted);font-size:13px;text-align:center;margin:auto;max-width:34ch;}
.msg{padding:9px 13px;border-radius:12px;max-width:88%;white-space:pre-wrap;font-size:13.5px;line-height:1.5;}
.msg.you{align-self:flex-end;background:var(--brand);color:#fff;border-bottom-right-radius:4px;}
.msg.bot{align-self:flex-start;background:var(--soft);border:1px solid var(--border);border-bottom-left-radius:4px;color:var(--ink-2);}
.msg.bot code{background:#fff;padding:1px 5px;border-radius:5px;font-family:var(--mono);font-size:12px;}
.msg.bot pre{background:#0e1526;color:#d7e2ff;border-radius:8px;padding:9px 11px;overflow-x:auto;font-family:var(--mono);font-size:12px;margin:6px 0;}
.msg.bot pre code{background:none;padding:0;color:inherit;}
.msg.bot hr,#concept hr{border:0;border-top:1px solid var(--border);margin:10px 0;}
.typing{display:inline-flex;gap:4px;padding:2px 0;}
.typing i{width:7px;height:7px;border-radius:50%;background:var(--muted-2);display:inline-block;animation:blink 1.2s infinite both;}
.typing i:nth-child(2){animation-delay:.2s;} .typing i:nth-child(3){animation-delay:.4s;}
@keyframes blink{0%,80%,100%{opacity:.25;transform:translateY(0);}40%{opacity:1;transform:translateY(-2px);}}
#tutor-form{display:flex;gap:8px;margin-top:10px;}
#tutor-input{flex:1;border:1px solid var(--border-2);border-radius:10px;padding:10px 13px;font:inherit;font-size:14px;background:var(--bg);}
#tutor-input:focus{outline:none;border-color:var(--brand);box-shadow:0 0 0 3px rgba(91,75,230,.15);}

/* footer nav prev/next */
.lesson-nav{display:flex;gap:10px;margin-top:30px;padding-top:20px;border-top:1px solid var(--border);}
.lesson-nav .btn{flex:1;justify-content:center;}
.lesson-nav .next{background:var(--brand);color:#fff;border-color:var(--brand);}
.lesson-nav .next:hover{background:var(--brand-ink);}

.spin{display:inline-block;width:13px;height:13px;border:2px solid rgba(255,255,255,.4);border-top-color:#fff;border-radius:50%;animation:sp .7s linear infinite;}
.ebtn.run .spin,.tab .spin{border-color:rgba(91,75,230,.3);border-top-color:var(--brand);}
@keyframes sp{to{transform:rotate(360deg);}}
::-webkit-scrollbar{width:10px;height:10px;}
::-webkit-scrollbar-thumb{background:#d5dae8;border-radius:8px;border:2px solid var(--bg);}
::-webkit-scrollbar-thumb:hover{background:#c2c9dc;}

/* responsive */
@media(max-width:1080px){
  .features{grid-template-columns:repeat(2,1fr);}
  .curric,.steps{grid-template-columns:1fr;}
  .hero .wrap{grid-template-columns:1fr;gap:40px;}
  .hero h1{font-size:42px;}
}
.nav-toggle{display:none;background:none;border:0;font-size:20px;line-height:1;cursor:pointer;color:var(--ink-2);padding:4px 8px;margin-right:2px;}
.nav-scrim{display:none;position:fixed;inset:0;background:rgba(15,23,42,.4);z-index:39;}
@media(max-width:900px){
  .nav-toggle{display:inline-block;}
  #content{width:46%;flex-basis:46%;}
  #sidebar{position:fixed;top:0;left:0;bottom:0;z-index:40;width:300px;max-width:86vw;
    transform:translateX(-100%);transition:transform .22s ease;box-shadow:var(--shadow-lg);padding-top:64px;}
  body.nav-open #sidebar{transform:translateX(0);}
  body.nav-open .nav-scrim{display:block;}
}
@media(max-width:680px){
  .nav .links a:not(.btn){display:none;}
  /* keep the slim progress bar; drop the fixed-width pills/labels that overflow ~360px headers */
  .appbar .pill,#aibadge{display:none;}
  .appbar .prog{min-width:0;}
  .appbar .ptext{display:none;}
  /* stacked mobile: let both panes shrink+scroll so the workbench stays reachable */
  .applayout{flex-direction:column;}
  #content{width:100%;flex:1 1 0;min-height:0;border-right:0;max-height:50vh;}
  #workbench{min-height:0;flex:1 1 0;}
  .cta-band{padding:36px 22px;}
}

/* respect reduced-motion: neutralize hover transforms, transitions, drawer slide, spinner + typing dots */
@media (prefers-reduced-motion: reduce){
  *,*::before,*::after{animation-duration:.001ms!important;animation-iteration-count:1!important;transition-duration:.001ms!important;}
  .btn:hover,.feat:hover,.mcard:hover{transform:none;}
}

/* ---------------- figures (data-driven charts) ---------------- */
.fig{margin:20px 0;padding:16px;background:var(--card);border:1px solid var(--border);border-radius:var(--r);box-shadow:var(--shadow);}
.fig-title{font-weight:700;font-size:14px;color:var(--ink);margin-bottom:6px;}
.fig-svg{width:100%;height:auto;max-width:600px;display:block;margin:0 auto;}
.fig-cap{font-size:13px;color:var(--muted);margin-top:8px;line-height:1.5;}
.fig-tick{font-size:10px;fill:var(--muted);}
.fig-axis{font-size:11.5px;fill:var(--ink-2);font-weight:600;}
.fig-legend{font-size:11px;fill:var(--ink-2);}

/* ---------------- comprehension questions ---------------- */
.qsec{margin:24px 0 6px;}
.qsec-h{font-size:15px;font-weight:800;color:var(--accent-ink);letter-spacing:.01em;margin-bottom:12px;
  padding-bottom:8px;border-bottom:2px solid var(--accent-soft);}
.qcard{background:var(--card);border:1px solid var(--border);border-radius:var(--r);padding:16px 18px;margin-bottom:14px;box-shadow:var(--shadow);}
.qhead{display:flex;align-items:center;gap:10px;margin-bottom:8px;}
.qnum{font-weight:800;font-size:12px;color:var(--accent-ink);background:var(--accent-soft);border-radius:100px;padding:2px 9px;}
.qtype{font-size:11px;font-weight:700;text-transform:uppercase;letter-spacing:.05em;color:var(--muted-2);}
.qprompt{font-size:15px;color:var(--ink);margin-bottom:12px;line-height:1.55;}
.qprompt code,.qopt code,.qexpl code,.qref code{background:var(--soft2);padding:1px 5px;border-radius:5px;font-family:var(--mono,monospace);font-size:.9em;}
.qopt{display:flex;align-items:flex-start;gap:9px;padding:9px 11px;border:1px solid var(--border);border-radius:9px;margin-bottom:7px;cursor:pointer;transition:.12s;font-size:14.5px;}
.qopt:hover{border-color:var(--accent);background:var(--accent-soft);}
.qopt input{margin-top:3px;flex:0 0 auto;accent-color:var(--accent);}
.qmatch{display:flex;flex-direction:column;gap:9px;}
.qmatch-row{display:flex;align-items:center;gap:12px;flex-wrap:wrap;}
.qmatch-l{flex:1 1 200px;font-size:14.5px;color:var(--ink);}
.qmatch-row select{flex:0 1 240px;padding:7px 10px;border:1px solid var(--border-2);border-radius:8px;font-size:14px;background:var(--bg);color:var(--ink);}
.qshort{width:100%;padding:10px 12px;border:1px solid var(--border-2);border-radius:9px;font-family:inherit;font-size:14.5px;resize:vertical;color:var(--ink);background:var(--bg);}
.qactions{margin-top:12px;}
.qsubmit{font-size:13px;padding:7px 18px;}
.qfeedback{margin-top:12px;font-size:14px;line-height:1.55;}
.qfeedback:empty{margin:0;}
.qfeedback.ok{color:var(--accent-ink);background:var(--accent-soft);border-radius:8px;padding:10px 12px;}
.qfeedback.bad{color:#b91c1c;background:#fef2f2;border-radius:8px;padding:10px 12px;}
.qfeedback.warn{color:#92610a;background:#fffbeb;border-radius:8px;padding:10px 12px;}
.qexpl{margin-top:8px;color:var(--ink-2);font-size:13.5px;}
.qref{margin-top:8px;color:var(--ink-2);font-size:13.5px;border-top:1px dashed var(--border-2);padding-top:8px;}
.qsec-done{text-align:center;}
.qdone-msg{display:inline-block;margin-top:4px;font-weight:800;color:var(--accent-ink);background:var(--accent-soft);border-radius:100px;padding:8px 18px;font-size:14px;}

/* interleaved project groups (unlocked after their module) */
.proj-group .mod-title.proj-t{color:var(--accent-ink);}
.proj-group{background:linear-gradient(180deg,var(--accent-soft),transparent 60%);border-radius:10px;margin:4px 6px;}