:root{color-scheme:light;--bg:#faf9fc;--panel:#fff;--soft:#f1eef7;--text:#24202d;--muted:#615a6d;--line:#ddd8e5;--purple:#6650c7;--tint:#eee7ff;--onpurple:#fff;--shadow:0 14px 50px #39224f0c}
:root[data-theme=dark]{color-scheme:dark;--bg:#181719;--panel:#222124;--soft:#29272e;--text:#f3f0f8;--muted:#bdb7c8;--line:#423d4c;--purple:#b7a5ff;--tint:#332945;--onpurple:#211631;--shadow:0 14px 50px #0002}
*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--text);font:18px/1.65 -apple-system,BlinkMacSystemFont,'Segoe UI',sans-serif}button,input,textarea,select{font:inherit}button,a,input,textarea,select{-webkit-tap-highlight-color:transparent}button,a{touch-action:manipulation}a{color:inherit}button{cursor:pointer}button:disabled{opacity:.55;cursor:wait}button,a{border-radius:12px}button:focus-visible,a:focus-visible,summary:focus-visible,input:focus-visible,textarea:focus-visible,select:focus-visible{outline:3px solid var(--purple);outline-offset:4px}button{border:1px solid var(--line);background:var(--panel);color:var(--text);padding:10px 18px;min-height:48px}input,textarea,select{background:var(--panel);color:var(--text);border:1px solid var(--line);border-radius:12px;padding:14px;width:100%}textarea{min-height:130px;resize:vertical;line-height:1.6}label{display:block;font-weight:600;margin:14px 0 8px}h1,h2,h3,p{margin:0 0 18px}h1{font-size:clamp(38px,5vw,68px);line-height:1.1;letter-spacing:-.045em}h2{font-size:32px;line-height:1.22;letter-spacing:-.025em}h3{font-size:23px;line-height:1.35}p{max-width:72ch}small,.small{font-size:16px;color:var(--muted)}.muted{color:var(--muted)}.site-header{max-width:1280px;margin:auto;padding:22px 32px;display:flex;justify-content:space-between;align-items:center;gap:20px}.brand{display:flex;align-items:center;gap:12px;font-size:22px;font-weight:750;text-decoration:none}.brand span{color:var(--purple);font-size:32px}.site-header nav{display:flex;align-items:center;gap:24px}.site-header nav a{text-decoration:none}.site-header nav button{font-size:24px;padding:4px 14px}main{max-width:1180px;margin:auto;padding:28px 32px 70px;min-height:65vh}footer{border-top:1px solid var(--line);padding:32px;display:flex;justify-content:center;gap:24px;flex-wrap:wrap;font-size:16px;color:var(--muted)}.eyebrow{color:var(--purple);font-size:16px;letter-spacing:.08em;font-weight:700;text-transform:uppercase}.hero{padding:55px 0;max-width:850px}.hero p:not(.eyebrow){font-size:22px;color:var(--muted);max-width:630px}.hero em{font-family:Georgia,serif;color:var(--purple);font-weight:500}.pill{display:inline-flex;gap:8px;align-items:center;border:1px solid var(--purple);background:var(--tint);border-radius:40px;padding:8px 18px;margin-bottom:24px;color:var(--purple);font-weight:600}.primary,.secondary{display:inline-flex;align-items:center;justify-content:center;gap:12px;min-height:50px;padding:12px 22px;text-decoration:none;font-weight:650;border-radius:28px;border:1px solid var(--line)}.primary{background:var(--purple);color:var(--onpurple);border-color:var(--purple)}.secondary{background:var(--panel);color:var(--text)}.links{display:flex;align-items:center;gap:18px;flex-wrap:wrap}.cards{display:grid;grid-template-columns:1fr 1fr;gap:24px}.card,.panel{padding:30px;border:1px solid var(--line);border-radius:22px;background:var(--panel);box-shadow:var(--shadow)}.card{display:flex;flex-direction:column}.card p{color:var(--muted)}.card .links{margin-top:auto;padding-top:12px}.card-icon{display:inline-grid;place-items:center;width:54px;height:54px;background:var(--tint);color:var(--purple);border-radius:16px;margin-bottom:22px;font-size:27px}.section{margin-top:64px}.section-intro{max-width:720px;margin-bottom:28px}.step-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:28px}.step-grid strong{display:block;color:var(--purple);margin-bottom:8px}.step-grid p{color:var(--muted)}.feature-list{padding-left:22px}.feature-list li{margin-bottom:10px}.stage{padding:24px 0;border-bottom:1px solid var(--line)}.stage:last-child{border:0}.stage summary{cursor:pointer;display:flex;gap:16px;align-items:center;font-weight:650}.stage summary span:first-child{color:var(--purple)}.stage ol{padding-left:54px;color:var(--muted)}.stage li{margin:12px 0}.stage button{border:0;background:none;text-align:left;padding:6px 8px;width:100%}.stage button[aria-current=step]{background:var(--tint);color:var(--purple)}.stage button:disabled{opacity:.8;cursor:default}.auth{max-width:560px;margin:40px auto}.auth input{margin:5px 0 16px}.auth .primary{width:100%}.divider{text-align:center;color:var(--muted);margin:18px 0}.auth .secondary{width:100%}.auth h1{font-size:38px}.course-heading{display:flex;justify-content:space-between;gap:22px;align-items:flex-start;margin-bottom:32px}.course-heading h1{font-size:36px}.course-heading a{color:var(--muted)}.lesson-layout{display:grid;grid-template-columns:240px minmax(0,1fr);gap:40px}.lesson-nav{position:sticky;top:24px;align-self:start;max-height:85vh;overflow:auto}.lesson-nav summary{padding:10px 0}.lesson-nav .stage{padding:8px 0}.lesson-nav .stage ol{padding-left:12px;list-style:none}.lesson-nav .stage button{font-size:16px}.lesson-main{min-width:0;max-width:800px}.lesson-main h1{font-size:38px;margin-bottom:20px}.teaching{border-left:3px solid var(--purple);padding:6px 0 6px 22px;margin:25px 0}.teaching p:last-child{margin-bottom:0}.task{background:var(--tint);border:1px solid var(--line);border-radius:18px;padding:24px;margin:24px 0}.task p:last-child{margin-bottom:0}.source{margin:24px 0}.source summary{cursor:pointer;font-weight:600;padding:12px 0}.source p{white-space:pre-line;color:var(--muted);padding:16px;background:var(--soft);border-radius:14px}.conversation{display:flex;flex-direction:column;gap:24px;margin:30px 0}.message{min-width:0;overflow-wrap:anywhere}.message .message-label{font-size:16px;color:var(--muted);margin-bottom:8px}.message.user{background:var(--soft);padding:18px 24px;border-radius:20px;margin-left:24px}.message p{white-space:pre-wrap}.message pre{white-space:pre-wrap;background:var(--soft);padding:14px}.message h3{margin-top:20px}.message ul{padding-left:24px}.composer{margin:24px 0}.composer .links{margin-top:14px;justify-content:space-between}.review-actions{margin:28px 0;padding-top:24px;border-top:1px solid var(--line);display:flex;gap:16px;flex-wrap:wrap}.feedback{padding:28px;border:1px solid var(--line);border-radius:20px;margin:28px 0;background:var(--panel)}.feedback.passed{border:2px solid var(--purple);background:var(--tint);box-shadow:0 0 22px color-mix(in srgb,var(--purple) 18%,transparent)}.feedback.passed .trophy{font-size:40px;color:var(--purple)}.feedback ul{padding-left:23px}.feedback li{margin:14px 0}.progress{height:7px;background:var(--line);border-radius:8px;overflow:hidden;margin:18px 0 8px}.progress span{display:block;background:var(--purple);height:100%}.saved-pieces{margin-top:24px}.saved-pieces summary{cursor:pointer;padding:12px 0}.history-row{display:flex;justify-content:space-between;gap:14px;margin:12px 0}.history-row button:first-child{text-align:left}.history-row button:last-child{color:var(--muted)}.empty{padding:60px 24px;text-align:center}.empty p{margin-inline:auto}.error{color:var(--text);background:var(--tint);padding:18px;border:1px solid var(--purple);border-radius:14px;margin:18px 0}.account-options{margin-top:30px;display:flex;gap:18px;flex-wrap:wrap}.account-options a,.text-button{background:transparent;border:0;text-decoration:underline;padding:4px;min-height:44px}.email-setting{margin-top:30px}.email-setting select{margin-bottom:16px}.course-status{margin-top:16px}.preview-result{margin-top:30px;background:var(--tint);border:1px solid var(--purple);padding:24px;border-radius:18px}.preview-result strong{display:block;font-size:22px;color:var(--purple)}dialog{width:min(580px,calc(100% - 32px));max-height:90dvh;overflow:auto;border:1px solid var(--line);border-radius:22px;background:var(--panel);color:var(--text);padding:30px}dialog::backdrop{background:#0009}dialog h2{margin-bottom:16px}dialog .links{margin-top:24px}#notice{position:fixed;bottom:24px;left:50%;transform:translateX(-50%);max-width:min(90%,600px);padding:14px 22px;border-radius:14px;background:var(--text);color:var(--bg);z-index:100;display:none}#notice.visible{display:block}.skip{position:absolute;top:-100px;left:16px;background:var(--panel);padding:12px;z-index:100}.skip:focus{top:10px}.access-summary{padding:22px;background:var(--tint);border-radius:16px;margin:20px 0}.access-summary strong{font-size:28px}.loading{padding:50px;text-align:center;color:var(--muted)}
@media(max-width:850px){.lesson-layout{grid-template-columns:1fr;gap:24px}.lesson-nav{position:static;max-height:none}.lesson-nav>.nav-body{display:none}.lesson-nav[open]>.nav-body{display:block}.lesson-nav>summary{display:block;cursor:pointer;border:1px solid var(--line);border-radius:14px;padding:12px 18px}.course-heading{flex-wrap:wrap}.step-grid{grid-template-columns:1fr}.hero{padding:30px 0}.hero h1{font-size:52px}}
@media(min-width:851px){.lesson-nav>summary{display:none}.lesson-nav>.nav-body{display:block!important}}
@media(max-width:600px){body{font-size:18px}.site-header{padding:16px;gap:8px}.brand{font-size:18px;gap:6px}.brand span{font-size:25px}.site-header nav{gap:10px}.site-header nav a{font-size:16px}.site-header nav button{padding:4px 10px}main{padding:24px 18px 50px}.cards{grid-template-columns:1fr}.card,.panel{padding:24px}.hero h1{font-size:42px}.hero p:not(.eyebrow){font-size:20px}.section{margin-top:42px}.course-heading h1,.lesson-main h1{font-size:32px}.task{padding:20px}.message.user{margin-left:12px}.composer .links{align-items:stretch}.composer .primary{width:100%}.feedback{padding:22px}.review-actions>*{flex:1;min-width:180px}.history-row{flex-wrap:wrap}.auth{margin:15px auto}.auth h1{font-size:34px}footer{gap:18px;padding:26px 18px}.course-heading .links{width:100%}dialog{padding:24px}.pill{font-size:16px}.lesson-nav .stage summary{font-size:17px}.teaching{padding-left:16px}}
@media(prefers-reduced-motion:no-preference){button,a{transition:background .15s,border-color .15s}.feedback.passed{animation:arrive .25s ease-out}@keyframes arrive{from{opacity:.4;transform:translateY(6px)}to{opacity:1;transform:none}}}