:root{
  --ink:#17201C; --ink-2:#55605A; --ink-3:#8A938D;
  --paper:#EBEDE8; --card:#F7F8F4; --band:#E3E6DF;
  --wash-1:rgba(240,242,236,.86); --wash-2:rgba(240,242,236,.74); --wash-3:rgba(240,242,236,.9);
  --photo-ink:#17201C; --photo-ink-2:#3C453F; --photo-ink-3:#68726C;
  --photo-filter:saturate(.3) brightness(1.16) contrast(.92);
  --photo-shadow:0 1px 12px rgba(255,255,255,.9);
  --photo-glow:rgba(242,244,238,.62);
  --cta-photo:#0F6E56; --cta-photo-ink:#EAF7F1;
  --line:rgba(23,32,28,.15); --line-soft:rgba(23,32,28,.08);
  --accent:#0F6E56; --accent-ink:#0F6E56; --accent-soft:#E1F5EE; --accent-on:#E8F7F1;
  --sans:'Inter',system-ui,-apple-system,'Segoe UI',sans-serif;
  --serif:'Newsreader',Georgia,'Times New Roman',serif;
  --pad:clamp(20px,5vw,56px);
}
@media (prefers-color-scheme:dark){:root:not([data-theme='light']){
  --ink:#E9EDEA; --ink-2:#9EA9A3; --ink-3:#727C77;
  --paper:#121512; --card:#191E1B; --band:#161A17;
  --wash-1:rgba(8,14,11,.80); --wash-2:rgba(8,14,11,.70); --wash-3:rgba(8,14,11,.88);
  --photo-ink:#FFFFFF; --photo-ink-2:rgba(255,255,255,.94); --photo-ink-3:rgba(255,255,255,.72);
  --photo-filter:saturate(.85);
  --photo-shadow:0 1px 16px rgba(6,11,9,.6);
  --photo-glow:rgba(8,14,11,.5);
  --cta-photo:#22A87D; --cta-photo-ink:#042018;
  --line:rgba(233,237,234,.14); --line-soft:rgba(233,237,234,.07);
  --accent:#1D9E75; --accent-ink:#9FE1CB; --accent-soft:rgba(29,158,117,.16); --accent-on:#04211A;
}}
:root[data-theme='dark']{
  --ink:#E9EDEA; --ink-2:#9EA9A3; --ink-3:#727C77;
  --paper:#121512; --card:#191E1B; --band:#161A17;
  --wash-1:rgba(8,14,11,.80); --wash-2:rgba(8,14,11,.70); --wash-3:rgba(8,14,11,.88);
  --photo-ink:#FFFFFF; --photo-ink-2:rgba(255,255,255,.94); --photo-ink-3:rgba(255,255,255,.72);
  --photo-filter:saturate(.85);
  --photo-shadow:0 1px 16px rgba(6,11,9,.6);
  --photo-glow:rgba(8,14,11,.5);
  --cta-photo:#22A87D; --cta-photo-ink:#042018;
  --line:rgba(233,237,234,.14); --line-soft:rgba(233,237,234,.07);
  --accent:#1D9E75; --accent-ink:#9FE1CB; --accent-soft:rgba(29,158,117,.16); --accent-on:#04211A;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--paper);color:var(--ink);font-family:var(--sans);font-size:16px;line-height:1.65;-webkit-font-smoothing:antialiased}
.wrap{max-width:980px;margin:0 auto;padding:0 var(--pad)}
section{border-top:1px solid var(--line-soft)}
h1,h2,h3{font-weight:500;margin:0}
h1{font-family:var(--serif);font-size:clamp(38px,7vw,60px);line-height:1.08;letter-spacing:-.015em}
h2{font-size:21px;letter-spacing:-.005em}
h3{font-size:15px}
p{margin:0}
a{color:inherit}
.eyebrow{font-size:11px;letter-spacing:.16em;text-transform:uppercase;color:var(--ink-3);margin-bottom:14px}
.lede{color:var(--ink-2);font-size:15px;line-height:1.7}
.small{font-size:13.5px;color:var(--ink-2);line-height:1.65}
.muted{color:var(--ink-3)}
.cta{display:inline-block;background:var(--accent);color:var(--accent-on);border:1px solid var(--accent);border-radius:6px;padding:13px 26px;font-size:15px;font-weight:500;text-decoration:none;transition:opacity .15s ease}
.cta:hover{opacity:.87}
.cta.ghost{background:transparent;color:var(--ink);border-color:var(--line);}
.cta.sm{padding:9px 17px;font-size:14px}
a:focus-visible,button:focus-visible{outline:2px solid var(--accent);outline-offset:3px;border-radius:4px}

/* nav */
.nav{position:sticky;top:0;z-index:20;background:color-mix(in srgb,var(--paper) 92%,transparent);backdrop-filter:blur(8px);border-bottom:1px solid var(--line-soft)}
.nav-in{display:flex;align-items:center;justify-content:space-between;height:64px}
.brand{display:flex;align-items:center;gap:10px;font-weight:500;font-size:16px;text-decoration:none}
.brand i{color:var(--accent);font-size:20px}
.nav-links{display:flex;align-items:center;gap:26px;font-size:14px;color:var(--ink-2)}
.nav-links a{text-decoration:none}
.nav-links a:hover{color:var(--ink)}
@media(max-width:720px){.nav-links a:not(.cta){display:none}}

/* photo panels */
.photo{position:relative;isolation:isolate;overflow:hidden;color:var(--photo-ink)}
.photo-bg{position:absolute;inset:0;background-size:cover;background-repeat:no-repeat;z-index:-2}
.photo:before{content:'';position:absolute;inset:0;z-index:-1;
  background:linear-gradient(180deg,var(--wash-1) 0%,var(--wash-2) 42%,var(--wash-3) 100%)}
.photo-bg{filter:var(--photo-filter)}
.hero.photo .photo-bg{transform:scale(1.06);filter:blur(2px) var(--photo-filter)}
.hero.photo:after{content:'';position:absolute;left:50%;top:50%;transform:translate(-50%,-50%);
  width:min(920px,94%);height:min(560px,90%);z-index:-1;border-radius:50%;
  background:radial-gradient(ellipse at center,var(--photo-glow) 0%,transparent 72%)}
.photo h1,.photo h2,.photo h3{color:var(--photo-ink)}
.photo .sub,.photo .lede,.photo p{color:var(--photo-ink-2);text-shadow:var(--photo-shadow)}
.photo h1,.photo h2{text-shadow:var(--photo-shadow)}
.photo .eyebrow{text-shadow:var(--photo-shadow)}
.photo .eyebrow,.photo .muted{color:var(--photo-ink-3)}
.photo .cta{background:var(--cta-photo);border-color:var(--cta-photo);color:var(--cta-photo-ink)}
.hero.photo{padding:clamp(92px,13vw,152px) 0 clamp(76px,10vw,112px)}
.close.photo{padding:clamp(84px,11vw,124px) 0}

/* theme toggle */
.theme-toggle{width:36px;height:36px;flex:none;display:inline-flex;align-items:center;justify-content:center;
  border:1px solid var(--line);border-radius:100px;background:transparent;color:var(--ink-2);
  font-size:17px;cursor:pointer;transition:color .15s ease,border-color .15s ease}
.theme-toggle:hover{color:var(--ink);border-color:var(--ink-3)}

/* hero */
.hero{padding:clamp(56px,10vw,104px) 0 clamp(40px,7vw,64px);text-align:center}
.hero p.sub{max-width:560px;margin:20px auto 30px;font-size:clamp(16px,2.2vw,18px);color:var(--ink-2);line-height:1.6}
.hero-actions{display:flex;flex-wrap:wrap;gap:14px;align-items:center;justify-content:center}

/* stats */
.stats{display:grid;grid-template-columns:repeat(4,1fr);border-top:1px solid var(--line);border-bottom:1px solid var(--line)}
.stat{padding:22px 12px;text-align:center;border-left:1px solid var(--line-soft)}
.stat:first-child{border-left:none}
.stat b{display:block;font-family:var(--serif);font-size:28px;font-weight:400;letter-spacing:-.01em}
.stat span{font-size:12.5px;color:var(--ink-3)}
@media(max-width:640px){.stats{grid-template-columns:repeat(2,1fr)}.stat:nth-child(3){border-left:none}.stat:nth-child(n+3){border-top:1px solid var(--line-soft)}}

/* generic section */
.sec{padding:clamp(44px,7vw,72px) 0}
.sec.band{background:var(--band)}
.sec-head{margin-bottom:26px}
.sec-head p{margin-top:8px;max-width:600px}

/* claim */
.claim{font-family:var(--serif);font-size:clamp(19px,2.7vw,25px);line-height:1.45;letter-spacing:-.01em;max-width:760px}
.claim-note{margin-top:20px;font-size:13.5px;color:var(--ink-3)}

/* cards: 1, 2 or 4 across, never 3 */
.cards{display:grid;grid-template-columns:1fr;gap:16px}
@media(min-width:560px){.cards{grid-template-columns:repeat(2,minmax(0,1fr))}}
@media(min-width:940px){.cards{grid-template-columns:repeat(4,minmax(0,1fr))}}
.card{background:var(--card);border:1px solid var(--line-soft);border-radius:10px;padding:22px}
.card i{font-size:21px;color:var(--accent)}
.card h3{margin:12px 0 6px}

/* ladder */
.ladder{display:flex;align-items:center;flex-wrap:wrap;gap:10px;margin-top:8px}
.rung{background:var(--accent-soft);color:var(--accent-ink);font-size:14px;padding:8px 16px;border-radius:100px;white-space:nowrap}
.ladder i{color:var(--ink-3);font-size:15px}

/* curriculum */
.mods{border-top:1px solid var(--line)}
.mod{display:flex;gap:18px;padding:20px 0;border-bottom:1px solid var(--line-soft)}
.num{flex:none;width:30px;height:30px;border-radius:100px;background:var(--accent-soft);color:var(--accent-ink);font-size:13px;font-weight:500;display:flex;align-items:center;justify-content:center;margin-top:1px}
.mod h3{margin-bottom:5px}
.mod ol{list-style:none;margin:0;padding:0;font-size:13.5px;color:var(--ink-2);line-height:1.8}
.mod li{display:inline}
.mod li:not(:last-child):after{content:' · ';color:var(--ink-3)}
.cur-head{display:flex;align-items:baseline;justify-content:space-between;gap:16px;flex-wrap:wrap;margin-bottom:20px}

/* certificate */
.cert{display:grid;grid-template-columns:1fr 260px;gap:32px;align-items:start}
@media(max-width:720px){.cert{grid-template-columns:1fr}}
.cert-card{background:var(--card);border:1px solid var(--line);border-radius:10px;padding:26px 22px;text-align:center}
.cert-card i{font-size:30px;color:var(--accent)}
.cert-card h3{margin:12px 0 6px}
.cert-card .cta{display:block;margin-top:18px}


/* faq */
.faq{border-top:1px solid var(--line-soft)}
.faq details{border-bottom:1px solid var(--line-soft)}
.faq summary{list-style:none;cursor:pointer;padding:18px 0;font-size:15.5px;font-weight:500;display:flex;justify-content:space-between;align-items:center;gap:16px}
.faq summary::-webkit-details-marker{display:none}
.faq summary:after{content:'\ea5f';font-family:'tabler-icons';font-weight:400;color:var(--ink-3);transition:transform .18s ease}
.faq details[open] summary:after{transform:rotate(180deg)}
.faq p{padding:0 0 20px;max-width:640px}

/* closing + footer */
.close{text-align:center;padding:clamp(52px,8vw,84px) 0}
.close h2{font-family:var(--serif);font-size:clamp(26px,4vw,34px);letter-spacing:-.01em}
.close p{max-width:440px;margin:14px auto 26px}
footer{border-top:1px solid var(--line-soft);padding:22px 0;font-size:13px;color:var(--ink-3)}
.foot-in{display:flex;justify-content:space-between;gap:16px;flex-wrap:wrap}
footer a{text-decoration:none}
footer a:hover{color:var(--ink)}
@media (prefers-reduced-motion:reduce){*{transition:none!important;scroll-behavior:auto!important}}


/* ============ course player ============ */
.player{display:grid;grid-template-columns:308px minmax(0,1fr);max-width:1280px;margin:0 auto}
.side{border-right:1px solid var(--line-soft);padding:24px 20px 56px;position:sticky;top:64px;
  align-self:start;max-height:calc(100vh - 64px);overflow-y:auto}
.side-list,.side-list ol{list-style:none;margin:0;padding:0}
.side-mod{margin-bottom:18px}
.side-mod-t{display:flex;gap:9px;align-items:center;font-size:13.5px;font-weight:500;margin:0 0 6px}
.side-n{width:20px;height:20px;flex:none;border-radius:100px;background:var(--accent-soft);color:var(--accent-ink);
  font-size:11px;display:flex;align-items:center;justify-content:center}
.side-les{display:flex;gap:8px;align-items:flex-start;padding:5px 8px 5px 6px;border-radius:6px;
  font-size:13px;line-height:1.45;color:var(--ink-2);text-decoration:none}
a.side-les:hover{background:var(--band);color:var(--ink)}
.side-les[aria-current]{background:var(--accent-soft);color:var(--accent-ink);font-weight:500}
.side-num{flex:none;font-variant-numeric:tabular-nums;color:var(--ink-3);font-size:11.5px;margin-top:1px}
.side-les[aria-current] .side-num{color:var(--accent-ink)}
.is-soon{color:var(--ink-3);font-style:italic}
.tick{flex:none;width:13px;height:13px;margin-top:2px;border:1px solid var(--line);border-radius:100px}
.side-les.is-done .tick{background:var(--accent);border-color:var(--accent);
  box-shadow:inset 0 0 0 2px var(--paper)}
.prog{margin-bottom:22px}
.prog-bar{height:4px;border-radius:4px;background:var(--band);overflow:hidden}
.prog-bar span{display:block;height:100%;width:0;background:var(--accent);transition:width .3s ease}
.prog-text{font-size:12px;color:var(--ink-3);margin-top:8px}

/* ============ lesson body ============ */
.lesson{padding:clamp(30px,5vw,54px) clamp(20px,4vw,56px) 90px}
.doc{padding:clamp(36px,6vw,72px) var(--pad) 90px}
.col{max-width:37rem;margin:0 auto}
.crumb{font-size:11px;letter-spacing:.14em;text-transform:uppercase;color:var(--ink-3);margin-bottom:12px}
.lesson h1,.doc h1{font-family:var(--serif);font-size:clamp(29px,4.4vw,42px);line-height:1.14;letter-spacing:-.015em}
.lesson-meta{font-size:13px;color:var(--ink-3);margin:14px 0 30px;padding-bottom:22px;border-bottom:1px solid var(--line-soft)}
.lesson-body p,.doc p{font-family:var(--serif);font-size:18.5px;line-height:1.72;margin:0 0 1.1em}
.lesson-body h3,.doc h3{font-family:var(--sans);font-size:13px;font-weight:500;letter-spacing:.1em;
  text-transform:uppercase;color:var(--ink-3);margin:2.4em 0 .9em}
.doc h2{font-family:var(--serif);font-size:24px;font-weight:500;letter-spacing:-.01em;
  margin:2.4em 0 .6em;padding-top:1.4em;border-top:1px solid var(--line-soft);text-transform:none;color:var(--ink)}
.doc h2:first-of-type{border-top:none;padding-top:0;margin-top:1.6em}
.doc .lede{font-family:var(--sans);font-size:16px;color:var(--ink-2);margin:14px 0 30px}
.exercise{background:var(--band);border:1px solid var(--line-soft);border-left:3px solid var(--accent);
  border-radius:8px;padding:6px 24px 22px;margin:2.4em 0}
.exercise h3{color:var(--accent-ink)}
.exercise p:last-child{margin-bottom:0}
.preface{background:var(--card);border:1px solid var(--line-soft);border-radius:8px;padding:6px 24px 20px;margin:0 0 2.6em}
.preface-t{font-family:var(--sans)!important;font-size:12px!important;letter-spacing:.12em;text-transform:uppercase;
  color:var(--ink-3);margin:20px 0 6px!important}
.preface p{font-size:16.5px;line-height:1.65}
.preface h3{margin-top:1.6em}
.handoff{border-top:1px solid var(--line-soft);margin-top:2.6em;padding-top:1.6em}
.handoff h3{color:var(--ink-3)}

/* ============ completion + pagers ============ */
.done{display:flex;flex-wrap:wrap;gap:6px 14px;align-items:center;margin:40px 0 30px;
  padding:16px 18px;border:1px solid var(--line-soft);border-radius:8px;background:var(--card)}
.done-box{display:flex;gap:9px;align-items:center;font-size:14.5px;font-weight:500;cursor:pointer}
.done-box input{width:16px;height:16px;accent-color:var(--accent)}
.done-note{font-size:12.5px;color:var(--ink-3)}
.pagers{display:grid;grid-template-columns:1fr 1fr;gap:12px}
.pager{display:flex;gap:10px;align-items:center;padding:14px 16px;border:1px solid var(--line-soft);
  border-radius:8px;text-decoration:none;font-size:13.5px;color:var(--ink-2);transition:border-color .15s ease}
.pager:hover{border-color:var(--ink-3);color:var(--ink)}
.pager b{display:block;font-size:11px;letter-spacing:.12em;text-transform:uppercase;color:var(--ink-3);
  font-weight:500;margin-bottom:3px}
.pager.next{justify-content:flex-end;text-align:right}
.pager i{font-size:17px;color:var(--ink-3)}

/* ============ landing tweaks ============ */
.mod-link{text-decoration:none}
.mod-link:hover{color:var(--accent-ink)}
.mod ol a{color:var(--ink-2);text-decoration:none;border-bottom:1px solid transparent}
.mod ol a:hover{color:var(--ink);border-bottom-color:var(--line)}
.soon{color:var(--ink-3);font-style:italic}
.buildwarn{background:#8A4B12;color:#fff;padding:10px var(--pad);font-size:13px}

@media(max-width:900px){
  .player{grid-template-columns:1fr}
  .side{position:static;max-height:none;border-right:none;border-bottom:1px solid var(--line-soft);
    padding:20px var(--pad) 28px}
  .pagers{grid-template-columns:1fr}
}