/* AI Math Tutor site. Tokens lifted from the app's own design system
   (theme/colors.ts): soft navy surfaces, warm peach brand accent, lavender
   for progress moments. Depth comes from surface colour, not borders.
   Newsreader for display type, Inter for everything else. */
:root {
  --bg:#1A1F36; --bg-deep:#0F1224; --bg-soft:#161B30; --card:#252B45; --card-2:#2F3554;
  --text:#FFF6EE; --text-2:#C9CFE2; --text-3:#A4ACCB; --text-4:#7C84AC;
  --border:#2F3554; --border-2:#404670;
  --peach:#F8C8A8; --peach-ink:#1A1F36; --peach-2:#E8A579; --peach-soft:rgba(248,200,168,.12);
  --lav:#A28DCE; --lav-soft:rgba(162,141,206,.16);
  --paper:#FFF6EE; --paper-2:#FDE7D3; --paper-ink:#1A1F36; --paper-muted:#5A608A;
  --success:#10B981;
  --r-sm:12px; --r-card:22px; --r-btn:14px; --r-chip:999px;
  --shadow:0 1px 0 rgba(255,246,238,.04) inset;
  --shadow-lg:0 40px 80px -30px rgba(0,0,0,.8), 0 0 0 1px rgba(255,246,238,.05);
  --glow:0 0 120px 20px rgba(248,200,168,.10);
  --wrap:1100px; --prose:740px;
  --sans:'Inter',-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,Helvetica,Arial,sans-serif;
  --serif:'Newsreader',Georgia,'Times New Roman',serif;
}
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth;background:var(--bg)}
@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}*{animation:none!important;transition:none!important}}
body{margin:0;background:var(--bg);color:var(--text);font-family:var(--sans);font-size:17px;line-height:1.65;
  -webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility}
img,svg{max-width:100%;height:auto}
a{color:var(--text);text-underline-offset:3px;text-decoration-color:var(--border-2)}
a:hover{color:var(--peach);text-decoration-color:var(--peach)}
h1,h2,h3{line-height:1.15;letter-spacing:-.02em;margin:0 0 .5em;font-weight:600;color:var(--text)}
h1,.h2,.title{font-family:var(--serif);font-weight:500;letter-spacing:-.01em}
p{margin:0 0 1em}
.skip{position:absolute;left:-9999px;top:0;background:var(--peach);color:var(--peach-ink);padding:10px 16px;z-index:99}
.skip:focus{left:8px;top:8px}
:focus-visible{outline:2px solid var(--peach);outline-offset:3px;border-radius:6px}

/* ---------- chrome ---------- */
.site-head{display:flex;align-items:center;gap:24px;flex-wrap:wrap;max-width:var(--wrap);margin:0 auto;padding:20px 24px}
.brand{display:inline-flex;align-items:center;gap:10px;font-weight:600;font-size:18px;color:var(--text);text-decoration:none;letter-spacing:-.01em}
.brand img{border-radius:9px}
.site-nav{display:flex;gap:24px;flex-wrap:wrap;margin-left:auto;font-size:15px;align-items:center}
.site-nav a{color:var(--text-2);text-decoration:none}
.site-nav a:hover{color:var(--text)}
.nav-cta{background:var(--peach);color:var(--peach-ink)!important;padding:9px 16px;border-radius:var(--r-chip);font-weight:600}
.nav-cta:hover{background:var(--peach-2)}
.site-foot{border-top:1px solid var(--border);margin-top:80px;background:var(--bg-deep)}
.foot-in{max-width:var(--wrap);margin:0 auto;padding:44px 24px 16px;display:flex;gap:32px;flex-wrap:wrap;justify-content:space-between}
.foot-brand{display:flex;gap:14px;align-items:flex-start;max-width:400px}
.foot-brand img{border-radius:10px}
.foot-brand p{margin:0;font-size:15px;color:var(--text-2)}
.foot-links{display:flex;flex-direction:column;gap:8px;font-size:15px}
.foot-links a{color:var(--text-2);text-decoration:none}
.foot-links a:hover{color:var(--text)}
.foot-legal{max-width:var(--wrap);margin:0 auto;padding:0 24px 44px;font-size:13px;color:var(--text-4);line-height:1.6}

/* ---------- layout ---------- */
.section{max-width:var(--wrap);margin:0 auto;padding:60px 24px}
.section.prose{max-width:var(--prose)}
.band{background:var(--bg-soft);max-width:none}
.band > *{max-width:var(--wrap);margin-left:auto;margin-right:auto}
.kicker{font-size:12.5px;letter-spacing:.14em;text-transform:uppercase;color:var(--peach);font-weight:600;margin:0 0 12px}
.kicker a{color:inherit;text-decoration:none}
.title{font-size:clamp(34px,4.8vw,52px);margin-bottom:.4em}
.h2{font-size:clamp(26px,3.2vw,36px);margin:1.6em 0 .6em}
.lede{font-size:19px;color:var(--text-2);max-width:62ch}
.muted{color:var(--text-2)}
.small{font-size:14px}
.plain{color:var(--peach);font-weight:500}
.chip{display:inline-block;font-size:12px;letter-spacing:.05em;text-transform:uppercase;font-weight:600;color:var(--text-2);background:var(--card-2);padding:5px 11px;border-radius:var(--r-chip);text-decoration:none}
.chip:hover{color:var(--peach-ink);background:var(--peach)}
.chips{display:flex;gap:8px;flex-wrap:wrap;margin:0 0 18px}

/* ---------- hero ---------- */
.hero{position:relative;max-width:var(--wrap);margin:0 auto;padding:48px 24px 72px;display:grid;grid-template-columns:1.1fr .9fr;gap:56px;align-items:center;overflow:visible}
.hero::before{content:"";position:absolute;right:-10%;top:-20%;width:60%;height:120%;background:radial-gradient(closest-side,rgba(248,200,168,.14),transparent 70%);pointer-events:none}
.hero-h{font-size:clamp(40px,6vw,72px);line-height:1.02;margin-bottom:.4em;font-weight:500}
.hero-h em{font-style:italic;color:var(--peach);font-weight:400}
.hero-sub{font-size:20px;color:var(--text-2);max-width:38ch;margin-bottom:1.6em}
.hero-actions{display:flex;flex-direction:column;gap:14px;align-items:flex-start}
.hero-note{font-size:14px;color:var(--text-3);margin:0;max-width:44ch}
.badge-link img{display:block}
.ways{display:flex;gap:10px;flex-wrap:wrap;margin:22px 0 0;padding:0;list-style:none;font-size:13.5px;color:var(--text-3)}
.ways li{display:inline-flex;align-items:center;gap:7px;background:var(--card);padding:7px 12px;border-radius:var(--r-chip)}
.ways i{width:7px;height:7px;border-radius:50%;display:inline-block;background:var(--peach)}
.hero-visual{position:relative;display:flex;justify-content:center;align-items:center}
.shot{margin:0;text-align:center;position:relative;z-index:1}
.shot img{border-radius:34px;box-shadow:var(--shadow-lg),var(--glow);background:var(--card);display:block}
.shot figcaption{font-size:13px;color:var(--text-3);margin-top:12px}

/* the worked-solution card on the landing page */
.solution{background:var(--paper);color:var(--paper-ink);border-radius:var(--r-card);padding:26px 28px;max-width:440px;box-shadow:var(--shadow-lg);font-size:16px;line-height:1.55}
.solution .prob{font-family:var(--serif);font-size:15px;color:var(--paper-muted);margin:0 0 6px;letter-spacing:.02em;text-transform:uppercase;font-weight:600;font-family:var(--sans);font-size:12px}
.solution .prob-math{font-size:22px;margin:0 0 16px}
.solution ol{list-style:none;padding:0;margin:0;counter-reset:st}
.solution li{position:relative;padding:0 0 12px 40px;margin:0 0 4px}
.solution li::before{counter-increment:st;content:counter(st);position:absolute;left:0;top:2px;width:28px;height:28px;border-radius:50%;background:var(--peach);color:var(--peach-ink);font-weight:700;font-size:13px;display:grid;place-items:center}
.solution li .why{display:block;color:var(--paper-muted);font-size:14px;margin-bottom:2px}
.solution li .math{display:block;font-size:17px}
.solution .ans{margin:8px 0 0;padding-top:12px;border-top:1px solid var(--paper-2);font-weight:600}
.solution .katex{font-size:1.05em}

/* ---------- steps / feature cards ---------- */
.steps{list-style:none;padding:0;margin:0;display:grid;grid-template-columns:repeat(3,1fr);gap:20px}
.step{background:var(--card);border-radius:var(--r-card);padding:26px;box-shadow:var(--shadow)}
.step .num{display:inline-grid;place-items:center;width:32px;height:32px;border-radius:50%;background:var(--peach);color:var(--peach-ink);font-weight:700;font-size:14px;margin-bottom:14px}
.step h3{font-size:19px;margin-bottom:.4em}
.step p{margin:0;color:var(--text-2);font-size:15.5px}
.cards{display:grid;grid-template-columns:repeat(3,1fr);gap:20px;margin-top:28px}
.card{background:var(--card);border-radius:var(--r-card);padding:24px;box-shadow:var(--shadow)}
.card h3{font-size:18px;margin-bottom:.4em}
.card p{margin:0;color:var(--text-2);font-size:15.5px}
.card a{text-decoration:none}
.card.ai{border:1px solid rgba(162,141,206,.4)}
.card .num{font-size:36px;font-weight:600;letter-spacing:-.02em;color:var(--peach);display:block;margin-bottom:6px;line-height:1;font-family:var(--serif)}
.topics{display:flex;flex-wrap:wrap;gap:10px;margin:20px 0 0;padding:0;list-style:none}
.topics li{background:var(--card);border-radius:var(--r-chip);padding:8px 14px;font-size:14.5px;color:var(--text-2)}

/* ---------- honesty block ---------- */
.honesty{background:var(--card);border-left:4px solid var(--peach);border-radius:var(--r-card);padding:30px 32px}
.honesty h2{margin-top:0}
.honesty p:last-child{margin-bottom:0}

/* ---------- plans ---------- */
.plans{display:grid;grid-template-columns:1fr 1fr;gap:20px;margin-top:20px}
.plan{background:var(--card);border-radius:var(--r-card);padding:28px}
.plan.pro{border:1px solid rgba(248,200,168,.4)}
.plan h3{font-size:22px;margin-bottom:.2em;font-family:var(--serif);font-weight:500}
.plan .plan-sub{color:var(--text-2);font-size:15px;margin-bottom:14px}
.plan ul{list-style:none;padding:0;margin:0}
.plan li{padding:9px 0;border-top:1px solid var(--border);font-size:15.5px}
.plan li:first-child{border-top:0}

/* ---------- conversion block ---------- */
.cta{max-width:var(--wrap);margin:32px auto;padding:30px 32px;background:var(--card);border-radius:var(--r-card);box-shadow:var(--shadow);
  display:flex;gap:32px;align-items:center;justify-content:space-between;flex-wrap:wrap}
.cta-copy{flex:1 1 300px}
.cta-h{font-size:24px;margin-bottom:.3em;font-family:var(--serif);font-weight:500}
.cta-sub{margin:0;color:var(--text-2);font-size:15.5px;max-width:50ch}
.cta-action{display:flex;gap:24px;align-items:center;flex-wrap:wrap}
.cta-qr{text-align:center}
.qr-canvas{display:inline-grid;place-items:center;background:#fff;border-radius:12px;padding:8px}
.qr-canvas svg{display:block;min-width:200px;min-height:200px}
.qr-label{margin:8px 0 0;font-size:13px;color:var(--text-2);font-weight:500}
.cta-badge img{display:block}
.cta-android{max-width:360px}
.android-note{margin:0;font-size:15px;color:var(--text-2)}

/* ---------- FAQ ---------- */
.faq{border-top:1px solid var(--border)}
.faq-item{border-bottom:1px solid var(--border)}
.faq-item summary{cursor:pointer;padding:18px 0;font-weight:600;font-size:17px;list-style:none;display:flex;justify-content:space-between;gap:16px}
.faq-item summary::-webkit-details-marker{display:none}
.faq-item summary::after{content:'+';color:var(--peach);font-weight:400;font-size:22px;line-height:1}
.faq-item[open] summary::after{content:'\2212'}
.faq-a{padding-bottom:6px;color:var(--text-2)}
.faq-a p:last-child{margin-bottom:1em}

/* ---------- prose / docs ---------- */
.prose h2{font-size:clamp(23px,2.8vw,29px);margin:2em 0 .5em}
.prose h3{font-size:19px;margin:1.6em 0 .4em}
.prose ul,.prose ol{padding-left:22px}
.prose li{margin:.35em 0}
.prose blockquote{margin:1.4em 0;padding:2px 0 2px 18px;border-left:3px solid var(--border-2);color:var(--text-2)}
.prose code{background:var(--card-2);padding:2px 6px;border-radius:6px;font-size:.9em}
.prose a{color:var(--peach);text-decoration-color:rgba(248,200,168,.4)}
.prose .katex-display{margin:1.1em 0;overflow-x:auto;overflow-y:hidden;padding:4px 0}
.prose .katex{font-size:1.08em}
.plainlist{list-style:none;padding:0}
.plainlist li{margin:.4em 0}
.linklist{list-style:none;padding:0;margin:24px 0 0}
.linklist li{padding:16px 0;border-bottom:1px solid var(--border)}
.linklist a{display:block;font-weight:600;font-size:18px;text-decoration:none;color:var(--text)}
.linklist a:hover{color:var(--peach)}
.linklist span{display:block;color:var(--text-2);font-size:15px;margin-top:4px}
.post-list{list-style:none;padding:0;margin:24px 0 0}
.post-row{padding:20px 0;border-bottom:1px solid var(--border);display:grid;grid-template-columns:1fr auto;gap:20px;align-items:start}
.post-row time{font-size:13px;color:var(--text-3)}
.post-row h2{font-size:21px;margin:.2em 0 .3em;font-family:var(--serif);font-weight:500}
.post-row h2 a{color:var(--text);text-decoration:none}
.post-row h2 a:hover{color:var(--peach)}
.post-row p{margin:0;color:var(--text-2);font-size:15.5px}
.post-row img{width:168px;height:94px;object-fit:cover;border-radius:12px;background:var(--card)}
.post .table-wrap table{border-collapse:collapse;width:100%;min-width:520px;font-size:15px}
.post .table-wrap th,.post .table-wrap td{border:1px solid var(--border);padding:10px 12px;text-align:left;vertical-align:top}
.post .table-wrap thead th{background:var(--card);font-weight:600}
.post .section-sub{margin-top:2.4em}
.post .section-sub .h2{margin-top:0}
.link-pending{color:var(--text-2);border-bottom:1px dotted var(--border-2)}
.table-wrap{overflow-x:auto;margin:20px 0;-webkit-overflow-scrolling:touch}
.disclosure{background:var(--card);border:1px solid var(--border-2);border-radius:14px;padding:14px 18px;margin:24px 0;font-size:14.5px;line-height:1.55;color:var(--text-2)}
.post-hero{margin:22px 0 28px;border-radius:var(--r-card);overflow:hidden;background:var(--card)}
.post-hero img{display:block;width:100%;height:auto}
/* worked examples read better on paper: an H3 that starts with "Example" opens a paper card */
.post h3.example{background:var(--paper);color:var(--paper-ink);border-radius:16px 16px 0 0;padding:16px 22px 0;margin:2em 0 0;font-family:var(--sans);font-size:17px}
.post .example-body{background:var(--paper);color:var(--paper-ink);border-radius:0 0 16px 16px;padding:8px 22px 18px;margin:0 0 1.6em}
.post .example-body a{color:#A86A43}
.post .example-body code{background:var(--paper-2)}
.post .example-body ol,.post .example-body ul{padding-left:22px}
.post .example-body p:last-child{margin-bottom:0}

/* ---------- latest posts on the landing page ---------- */
.latest-posts{list-style:none;padding:0;margin:0 0 18px;display:grid;gap:10px}
.latest-posts li{background:var(--card);border-radius:var(--r-card);padding:16px 18px}
.latest-posts time{display:block;font-size:13px;color:var(--text-3);margin-bottom:3px}
.latest-posts a{font-weight:600;font-size:17px;text-decoration:none;color:var(--text)}
.latest-posts a:hover{color:var(--peach)}
.latest:not(:has(li)){display:none}

/* ---------- responsive ---------- */
.hero-solution{display:none}
@media (max-width:900px){
  .hero{grid-template-columns:1fr;gap:36px;padding-top:16px}
  .shot-desktop{display:none}
  .hero-solution{display:block;width:100%}
  .hero-solution .solution{max-width:none}
  .hero-sub{max-width:none}
  .steps,.cards{grid-template-columns:1fr}
  .plans{grid-template-columns:1fr}
  .cta{gap:22px}
}
@media (max-width:620px){
  body{font-size:16.5px}
  .section{padding:44px 20px}
  .hero{padding:8px 20px 44px}
  .site-head{padding:14px 20px;gap:12px}
  .site-nav{margin-left:0;gap:14px;font-size:14px;width:100%}
  .shot img{border-radius:24px}
  .solution{padding:20px 18px;max-width:none}
  .cta{padding:22px 20px;margin:24px 20px}
  .honesty{padding:22px 20px}
  .foot-in{padding:32px 20px 12px}
  .post-row{grid-template-columns:1fr}
  .post-row img{width:100%;height:auto;aspect-ratio:16/9}
  .post-hero{margin:16px 0 20px;border-radius:14px}
}