/* Kudosli — production stylesheet */
:root{
  --bg:#f7f6f2;
  --surface:#ffffff;
  --surface-soft:#fbfaf7;
  --ink:#17203a;
  --ink-soft:#3c465e;
  --muted:#6b7280;
  --line:#e6e2d8;
  --line-strong:#d8d3c4;
  --brand:#2456d6;
  --brand-dark:#1b41a8;
  --brand-soft:#eaf0fe;
  --accent:#f59e0b;
  --accent-soft:#fef3d8;
  --success:#15803d;
  --success-soft:#e7f6ec;
  --danger:#c2261b;
  --danger-soft:#fdecea;
  --radius:16px;
  --radius-sm:10px;
  --shadow:0 1px 2px rgba(23,32,58,.05),0 8px 24px rgba(23,32,58,.06);
  --shadow-lg:0 2px 4px rgba(23,32,58,.06),0 20px 44px rgba(23,32,58,.10);
  --font:-apple-system,BlinkMacSystemFont,"Segoe UI",Inter,Roboto,"Helvetica Neue",Arial,sans-serif;
  --max:1120px;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;font-family:var(--font);background:var(--bg);color:var(--ink);line-height:1.6;font-size:16.5px;-webkit-font-smoothing:antialiased}
h1,h2,h3,h4{line-height:1.18;margin:0 0 .5em;letter-spacing:-.02em;color:var(--ink)}
h1{font-size:clamp(2rem,4.6vw,3.1rem);font-weight:800}
h2{font-size:clamp(1.5rem,3vw,2rem);font-weight:750;margin-top:0}
h3{font-size:1.15rem;font-weight:700}
p{margin:0 0 1em}
a{color:var(--brand);text-decoration:none}
a:hover{text-decoration:underline}
:focus-visible{outline:3px solid var(--accent);outline-offset:2px;border-radius:6px}
.wrap{max-width:var(--max);margin:0 auto;padding:0 20px}
.lede{font-size:1.16rem;color:var(--ink-soft);max-width:640px}
.muted{color:var(--muted)}
.small{font-size:.9rem}
.eyebrow{text-transform:uppercase;letter-spacing:.12em;font-size:.78rem;font-weight:700;color:var(--brand);margin-bottom:.7em}

/* Header */
.site-header{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.92);backdrop-filter:blur(10px);border-bottom:1px solid var(--line)}
.site-header .wrap{display:flex;align-items:center;gap:24px;min-height:64px}
.logo{font-weight:800;font-size:1.3rem;color:var(--ink);letter-spacing:-.02em;white-space:nowrap}
.logo:hover{text-decoration:none}
.logo span{color:var(--brand)}
.main-nav{display:flex;gap:4px;margin-left:auto;flex-wrap:wrap}
.main-nav a{color:var(--ink-soft);font-weight:550;padding:8px 12px;border-radius:999px;font-size:.97rem}
.main-nav a:hover{text-decoration:none;background:var(--surface-soft);color:var(--ink)}
.main-nav a[aria-current="page"]{background:var(--brand-soft);color:var(--brand-dark);font-weight:700}
.header-cta{margin-left:8px;white-space:nowrap}

/* Buttons */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;border:1px solid transparent;border-radius:999px;padding:11px 22px;font:inherit;font-weight:650;font-size:1rem;cursor:pointer;background:var(--brand);color:#fff;transition:background .15s,transform .05s,box-shadow .15s;text-decoration:none}
.btn:hover{background:var(--brand-dark);text-decoration:none}
.btn:active{transform:translateY(1px)}
.btn-secondary{background:var(--surface);color:var(--ink);border-color:var(--line-strong)}
.btn-secondary:hover{background:var(--surface-soft)}
.btn-gold{background:var(--accent);color:#231a02}
.btn-gold:hover{background:#d98a06}
.btn-sm{padding:8px 16px;font-size:.93rem}
.btn-block{display:flex;width:100%}
.btn[disabled]{opacity:.5;cursor:not-allowed}
.btn-row{display:flex;gap:12px;flex-wrap:wrap;margin-top:20px}

/* Layout sections */
.section{padding:64px 0}
.section-tight{padding:36px 0}
.hero{padding:72px 0 56px;background:linear-gradient(180deg,#fff 0%,var(--bg) 100%)}
.hero h1{max-width:760px}
.hero .lede{margin-bottom:8px}
.hero-note{margin-top:16px;color:var(--muted);font-size:.95rem}
.grid{display:grid;gap:20px}
.grid-2{grid-template-columns:repeat(2,1fr)}
.grid-3{grid-template-columns:repeat(3,1fr)}
.grid-4{grid-template-columns:repeat(4,1fr)}
.card{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:26px;box-shadow:var(--shadow)}
.card h3{margin-bottom:.35em}
.card p:last-child{margin-bottom:0}
.card-link{display:block;color:inherit}
.card-link:hover{text-decoration:none;border-color:var(--brand);box-shadow:var(--shadow-lg)}
.card .card-arrow{color:var(--brand);font-weight:700}

/* Stats */
.stat-strip{display:grid;grid-template-columns:repeat(4,1fr);gap:16px;margin-top:36px}
.stat{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:20px 22px}
.stat-num{font-size:1.9rem;font-weight:800;letter-spacing:-.02em;line-height:1.1}
.stat-label{color:var(--muted);font-size:.92rem;margin-top:2px}
.progress{height:10px;background:#eceade;border-radius:999px;overflow:hidden}
.progress>i{display:block;height:100%;background:var(--brand);border-radius:999px;transition:width .3s}
.progress.gold>i{background:var(--accent)}
.bar-row{display:grid;grid-template-columns:130px 1fr 52px;gap:12px;align-items:center;margin:10px 0}
.bar-row .bar-label{font-weight:600;font-size:.95rem}
.bar-row .bar-val{text-align:right;font-variant-numeric:tabular-nums;color:var(--ink-soft)}

/* Tables */
.table-wrap{overflow-x:auto;border:1px solid var(--line);border-radius:var(--radius);background:var(--surface)}
table{border-collapse:collapse;width:100%;font-size:.98rem}
th,td{padding:12px 16px;text-align:left;border-bottom:1px solid var(--line);vertical-align:top}
thead th{background:var(--surface-soft);font-size:.85rem;text-transform:uppercase;letter-spacing:.06em;color:var(--ink-soft)}
tbody tr:last-child td{border-bottom:none}

/* Pricing */
.price-card{display:flex;flex-direction:column}
.price-card.featured{border:2px solid var(--brand);box-shadow:var(--shadow-lg);position:relative}
.price-badge{position:absolute;top:-13px;left:24px;background:var(--brand);color:#fff;font-size:.78rem;font-weight:700;padding:4px 12px;border-radius:999px;letter-spacing:.04em}
.price{font-size:2.1rem;font-weight:800;letter-spacing:-.02em;line-height:1.1}
.price small{font-size:1rem;font-weight:550;color:var(--muted)}
.price-alt{color:var(--muted);font-size:.93rem;margin-bottom:14px}
.feature-list{list-style:none;padding:0;margin:0 0 22px;display:grid;gap:9px}
.feature-list li{padding-left:26px;position:relative;color:var(--ink-soft)}
.feature-list li::before{content:"✓";position:absolute;left:0;color:var(--success);font-weight:800}
.price-card .btn{margin-top:auto}

/* Forms */
label.field{display:block;font-weight:600;margin-bottom:14px}
label.field span{display:block;margin-bottom:6px}
input[type="text"],input[type="date"],input[type="number"],select,textarea{font:inherit;color:var(--ink);background:var(--surface);border:1px solid var(--line-strong);border-radius:var(--radius-sm);padding:11px 13px;width:100%}
input[type="text"]:focus,input[type="date"]:focus,input[type="number"]:focus,select:focus,textarea:focus{border-color:var(--brand);outline:3px solid var(--brand-soft)}
textarea{min-height:320px;resize:vertical;line-height:1.65}
.help{color:var(--muted);font-size:.9rem;font-weight:400}
.inline-form{display:flex;gap:10px;align-items:end;flex-wrap:wrap}
.inline-form .grow{flex:1;min-width:200px}

/* Question UI */
.q-shell{max-width:820px;margin:0 auto}
.q-meta{display:flex;justify-content:space-between;align-items:center;gap:12px;flex-wrap:wrap;margin-bottom:14px;color:var(--muted);font-size:.93rem;font-weight:600}
.tag{display:inline-block;background:var(--accent-soft);color:#7a5200;border-radius:999px;padding:3px 11px;font-size:.8rem;font-weight:700;letter-spacing:.02em}
.tag-blue{background:var(--brand-soft);color:var(--brand-dark)}
.stimulus{background:var(--surface-soft);border:1px solid var(--line);border-left:4px solid var(--brand);border-radius:var(--radius-sm);padding:18px 20px;margin-bottom:18px;white-space:pre-wrap}
.stem{font-size:1.12rem;font-weight:650;margin-bottom:18px}
.choices{display:grid;gap:10px;margin-bottom:20px}
.choice{display:flex;gap:12px;align-items:flex-start;background:var(--surface);border:1.5px solid var(--line-strong);border-radius:var(--radius-sm);padding:13px 16px;cursor:pointer;font-weight:500}
.choice:hover{border-color:var(--brand)}
.choice.selected{border-color:var(--brand);background:var(--brand-soft)}
.choice.correct{border-color:var(--success);background:var(--success-soft)}
.choice.incorrect{border-color:var(--danger);background:var(--danger-soft)}
.choice input{margin-top:4px;accent-color:var(--brand);width:18px;height:18px;flex:none}
.choice .letter{font-weight:800;flex:none}
.feedback{border-radius:var(--radius-sm);padding:18px 20px;margin:18px 0}
.feedback.good{background:var(--success-soft);border:1px solid #bfe6cb}
.feedback.bad{background:var(--danger-soft);border:1px solid #f3c7c2}
.feedback h3{margin-bottom:.3em}
.session-bar{display:flex;gap:18px;flex-wrap:wrap;align-items:center;background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:14px 20px;margin-bottom:20px;box-shadow:var(--shadow)}
.session-bar strong{font-size:1.05rem}
.timer{font-variant-numeric:tabular-nums;font-weight:800;font-size:1.25rem}
.timer.low{color:var(--danger)}
.check-list{list-style:none;padding:0;margin:0;display:grid;gap:10px}
.check-list label{display:flex;gap:11px;align-items:flex-start;background:var(--surface);border:1px solid var(--line);border-radius:var(--radius-sm);padding:13px 15px;cursor:pointer;font-weight:500}
.check-list input{margin-top:4px;width:18px;height:18px;accent-color:var(--brand);flex:none}
.miss-item{border-bottom:1px solid var(--line);padding:12px 0}
.miss-item:last-child{border-bottom:none}
.empty-note{background:var(--surface-soft);border:1px dashed var(--line-strong);border-radius:var(--radius);padding:28px;text-align:center;color:var(--ink-soft)}
.notice-bar{background:var(--accent-soft);border:1px solid #f2d492;border-radius:var(--radius-sm);padding:14px 18px;margin-bottom:20px}
details.faq{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:18px 22px;margin-bottom:12px}
details.faq summary{font-weight:700;cursor:pointer;font-size:1.05rem}
details.faq p{margin-top:10px;color:var(--ink-soft)}

/* Structured explanations */
.explanation-panel{margin-top:16px;display:grid;gap:18px;text-align:left}
.explanation-panel h4{font-size:1rem;margin-bottom:8px;color:var(--ink)}
.explain-right,.explain-wrong,.evidence-block{min-width:0}
.explain-sentences p,.explain-conclusion{margin:0 0 .55em;color:var(--ink-soft)}
.explain-sentences p:last-child,.explain-conclusion:last-child{margin-bottom:0}
.worked-steps{margin:0 0 12px;padding-left:1.45em;color:var(--ink-soft);display:grid;gap:6px}
.worked-steps li{padding-left:4px}
.worked-steps li::marker{color:var(--brand);font-weight:800}
.explanation-visual{margin:0}
.visual-frame{background:var(--surface);border:1px solid var(--line-strong);border-radius:var(--radius-sm);padding:14px;display:flex;justify-content:center;overflow:hidden}
.visual-frame svg{display:block;width:100%;max-width:520px;height:auto}
.explanation-visual figcaption{color:var(--muted);font-size:.86rem;font-weight:650;text-align:center;margin-top:7px}
.evidence-stimulus{margin-bottom:0}
.evidence-stimulus mark{background:#ffe58a;color:inherit;border-radius:3px;padding:0 2px;box-decoration-break:clone;-webkit-box-decoration-break:clone}
.wrong-list{list-style:none;margin:0;padding:0;display:grid;gap:10px}
.wrong-item{background:rgba(255,255,255,.62);border:1px solid var(--line);border-radius:var(--radius-sm);padding:12px 14px}
.wrong-item.chosen-wrong{border-color:var(--danger);background:#fff;box-shadow:inset 4px 0 0 var(--danger)}
.wrong-head{display:flex;gap:8px;align-items:baseline;flex-wrap:wrap;margin-bottom:3px}
.wrong-letter{font-weight:850;color:var(--ink)}
.wrong-choice{font-weight:600;color:var(--ink-soft)}
.wrong-item p{margin:0;color:var(--ink-soft)}
.your-answer-badge{display:inline-block;background:var(--danger);color:#fff;border-radius:999px;padding:2px 8px;font-size:.72rem;font-weight:800;letter-spacing:.03em;text-transform:uppercase}
details.faq .explanation-panel{margin-top:14px}

/* On-screen calculator */
.teachpass-calculator{position:fixed;right:20px;bottom:20px;z-index:120;font-family:var(--font)}
.calculator-toggle{display:inline-flex;align-items:center;gap:8px;border:1px solid var(--brand-dark);border-radius:999px;background:var(--brand);color:#fff;box-shadow:var(--shadow-lg);padding:11px 17px;font:inherit;font-weight:750;cursor:pointer}
.calculator-toggle:hover{background:var(--brand-dark)}
.calculator-toggle.math-available{background:var(--ink)}
.calculator-math-note{font-size:.78rem;font-weight:700;background:var(--accent);color:#231a02;border-radius:999px;padding:2px 7px}
.calculator-panel{position:fixed;right:20px;bottom:76px;width:308px;max-width:calc(100vw - 24px);background:var(--surface);border:1px solid var(--line-strong);border-radius:18px;box-shadow:var(--shadow-lg);padding:14px;user-select:none}
.calculator-panel[hidden]{display:none}
.calculator-head{display:flex;align-items:center;justify-content:space-between;font-weight:800;margin:-2px 0 10px;cursor:grab;touch-action:none}
.calculator-head:active{cursor:grabbing}
.calculator-close{border:0;background:transparent;color:var(--muted);font-size:1.45rem;line-height:1;cursor:pointer;padding:2px 6px}
.calculator-display{min-height:54px;border:1px solid var(--line-strong);border-radius:var(--radius-sm);background:var(--surface-soft);display:flex;align-items:center;justify-content:flex-end;padding:10px 13px;font-size:1.45rem;font-weight:750;font-variant-numeric:tabular-nums;overflow:hidden;white-space:nowrap;margin-bottom:12px}
.calculator-display.error{color:var(--danger);background:var(--danger-soft)}
.calculator-keys{display:grid;grid-template-columns:repeat(5,1fr);gap:8px}
.calculator-keys button{min-height:46px;border:1px solid var(--line);border-radius:11px;background:var(--surface);color:var(--ink);font:inherit;font-size:1.02rem;font-weight:700;cursor:pointer;padding:6px 2px}
.calculator-keys button:hover{border-color:var(--brand);background:var(--brand-soft)}
.calculator-keys button:active{transform:translateY(1px)}
.calculator-keys .calc-operator{background:var(--brand-soft);color:var(--brand-dark)}
.calculator-keys .calc-utility{background:var(--danger-soft);color:var(--danger)}
.calculator-keys .calc-equals{background:var(--brand);border-color:var(--brand);color:#fff;grid-column:span 2}
.calculator-keys .calc-equals:hover{background:var(--brand-dark)}

/* Articles and blog */
.article{max-width:760px;margin:0 auto}
.article h2{margin-top:1.6em}
.article h3{margin-top:1.4em}
.article p,.article li{color:var(--ink-soft)}
.article ul,.article ol{margin:0 0 1em;padding-left:1.3em;display:grid;gap:.45em}
.post-meta{color:var(--muted);font-size:.93rem;margin-bottom:8px}
.post-card{display:flex;flex-direction:column}
.post-card .post-meta{margin-bottom:4px}
.post-card .btn,.post-card .card-arrow{margin-top:auto}
.cta-band{background:var(--brand-soft);border:1px solid #c9d8fb;border-radius:var(--radius);padding:30px;text-align:center;margin-top:44px}
.cta-band h2{margin-bottom:.3em}
.cta-band p{color:var(--ink-soft);max-width:560px;margin:0 auto 6px}
.back-link{font-weight:600;font-size:.95rem;white-space:nowrap}

/* Footer */
.site-footer{border-top:1px solid var(--line);background:var(--surface);margin-top:72px;padding:36px 0 44px;color:var(--muted);font-size:.93rem}
.site-footer .foot-nav{display:flex;gap:18px;flex-wrap:wrap;margin-bottom:14px}
.site-footer a{color:var(--ink-soft);font-weight:550}

/* Responsive */
@media (max-width:900px){
  .grid-4,.stat-strip{grid-template-columns:repeat(2,1fr)}
  .grid-3{grid-template-columns:1fr}
  .grid-2{grid-template-columns:1fr}
}
@media (max-width:640px){
  body{font-size:16px}
  .section{padding:44px 0}
  .hero{padding:48px 0 40px}
  .site-header .wrap{gap:12px;flex-wrap:wrap;padding-top:10px;padding-bottom:10px}
  .main-nav{order:3;width:100%;margin-left:0;overflow-x:auto;flex-wrap:nowrap;padding-bottom:4px}
  .main-nav a{white-space:nowrap}
  .header-cta{margin-left:auto}
  .stat-strip{grid-template-columns:repeat(2,1fr)}
  .bar-row{grid-template-columns:96px 1fr 46px}
  .card{padding:20px}
  textarea{min-height:240px}
  .teachpass-calculator{right:12px;bottom:12px}
  .calculator-panel{left:12px;right:12px;bottom:70px;width:auto;max-width:none;max-height:calc(100dvh - 88px);overflow-y:auto}
  .calculator-head{cursor:default}
  .calculator-keys button{min-height:44px}
  .wrong-head{align-items:flex-start}
}