:root{--primary:#392B32;--secondary:#654653;--accent:#E4C98E;--muted:#A77D82;--bg:#F7F0DC;--surface:#FCF8EA;--raised:#EFE5C6;--line:#DCCFA8;--text:#392B32;--text-soft:#654653;--ok:#4F7A4A;--bad:#A5443F;--code:#392B32;--code-text:#F7F0DC;--radius:16px}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--text);font-family:Plus Jakarta Sans,system-ui,sans-serif;line-height:1.5}a{color:inherit}h1,h2{margin:0}.muted{color:var(--text-soft)}.small{font-size:13px}.mark{background:linear-gradient(transparent 62%,var(--accent) 62%)}.error{color:var(--bad);font-weight:600}.row{display:flex;gap:12px;flex-wrap:wrap;align-items:center}.row.spaced{justify-content:space-between;margin:20px 0 12px}.between{display:flex;justify-content:space-between;align-items:center;gap:12px}.grow{flex:1}:focus-visible{outline:3px solid var(--secondary);outline-offset:2px}.btn{border:0;border-radius:12px;padding:12px 20px;font-weight:600;font-size:15px;font-family:inherit;cursor:pointer;text-decoration:none;display:inline-block;min-height:44px}.btn.primary{background:var(--primary);color:var(--bg)}.btn.primary:hover{background:var(--secondary)}.btn.ghost{background:transparent;color:var(--primary);border:1.5px solid var(--muted)}.btn.ghost:hover{background:var(--raised)}.btn:disabled{opacity:.45;cursor:not-allowed}.btn.wide{width:100%}.link{background:none;border:0;color:var(--secondary);text-decoration:underline;cursor:pointer;font:inherit;margin-top:12px}.link-inline{color:var(--secondary);font-weight:600}.tag{background:var(--accent);color:var(--primary);border-radius:999px;padding:3px 10px;font-size:12px;font-weight:800;margin-left:8px;white-space:nowrap}.nav{display:flex;align-items:center;justify-content:space-between;padding:0 32px;height:72px;border-bottom:1px solid var(--line);position:sticky;top:0;background:var(--bg);z-index:5}.logo{display:flex;align-items:center;gap:10px;font-weight:800;font-size:20px;text-decoration:none;color:var(--primary)}.logo-mark{width:28px;height:28px;border-radius:9px;background:var(--primary);box-shadow:inset -8px -8px 0 var(--accent)}.nav-links a{color:var(--text-soft);text-decoration:none;font-weight:600;padding:8px 12px;border-radius:8px}.nav-links a.active{background:var(--accent);color:var(--primary)}.nav-right{display:flex;gap:14px;align-items:center}.page{max-width:1180px;margin:0 auto;padding:40px 32px 64px}.page.narrow{max-width:820px}.card{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:24px}.hero{display:grid;grid-template-columns:1.2fr 1fr;gap:40px;align-items:center;padding:24px 0 40px}.eyebrow{font-family:IBM Plex Mono,monospace;font-size:13px;color:var(--secondary);margin:0 0 10px;letter-spacing:.04em;font-weight:500}.eyebrow.top{margin-top:20px}.hero h1{font-size:clamp(36px,6vw,58px);line-height:1.05;font-weight:800;margin-bottom:16px}h1.big{font-size:clamp(34px,5vw,48px);font-weight:800;margin-bottom:12px}.lead{font-size:18px;color:var(--text-soft);max-width:560px;margin:0 0 26px}.continue h2{font-size:24px;margin:6px 0 4px}.continue .bar{margin:18px 0}.bar{height:10px;background:var(--raised);border-radius:6px;overflow:hidden;border:1px solid var(--line)}.bar span{display:block;height:100%;background:var(--secondary);border-radius:6px}.section{font-size:26px;margin:36px 0 16px}.grid3{display:grid;grid-template-columns:repeat(auto-fit,minmax(260px,1fr));gap:20px}.level{text-align:left;cursor:pointer;color:var(--text);font-family:inherit;display:flex;flex-direction:column;gap:6px}.level.active{border-color:var(--primary);background:var(--accent)}.level.active .muted{color:var(--primary)}.track{display:flex;flex-direction:column;gap:10px;text-decoration:none;transition:transform .15s}.track:hover{transform:translateY(-3px);border-color:var(--secondary)}.track p{margin:0}.track.soon{background:transparent;border-style:dashed;border-color:var(--muted)}.outcome{background:var(--accent);border-color:var(--accent);margin:8px 0}.syllabus{list-style:none;padding:0;margin:20px 0 0;display:flex;flex-direction:column;gap:10px}.row-item{display:flex;align-items:center;gap:16px;padding:14px 18px;background:var(--surface);border:1px solid var(--line);border-radius:14px;text-decoration:none}a.row-item:hover{border-color:var(--secondary);background:var(--raised)}.row-item.locked{opacity:.75;border-style:dashed}.num{width:34px;height:34px;border-radius:50%;background:var(--raised);display:grid;place-items:center;font-weight:800;color:var(--secondary);flex:none}.num.ok{background:var(--ok);color:#fff}.auth{max-width:420px;margin:56px auto;display:flex;flex-direction:column}.auth form{display:flex;flex-direction:column;gap:14px;margin-top:20px}label{display:flex;flex-direction:column;gap:6px;font-weight:600;font-size:14px}input[type=text],input[type=email],input[type=password],input:not([type]){background:#fff;border:1.5px solid var(--muted);color:var(--text);border-radius:10px;padding:12px;font:inherit}.lesson-layout{display:grid;grid-template-columns:260px minmax(0,1fr) 340px;min-height:calc(100vh - 72px)}.side{border-right:1px solid var(--line);padding:28px 16px;display:flex;flex-direction:column;gap:6px;background:var(--surface)}.side-title{font-weight:800;font-size:18px;text-decoration:none;margin-bottom:10px;padding:0 8px}.side a:not(.side-title){text-decoration:none;color:var(--text-soft);padding:10px 12px;border-radius:10px;font-size:14px;display:flex;gap:10px;align-items:center}.side a.cur{background:var(--accent);color:var(--primary);font-weight:700}.dot{width:24px;height:24px;border-radius:50%;background:var(--raised);display:grid;place-items:center;font-size:12px;font-weight:800;flex:none;color:var(--secondary)}.side a.cur .dot{background:var(--primary);color:var(--bg)}.lesson{padding:36px 44px;max-width:840px}.lesson h1{font-size:38px;font-weight:800;margin:6px 0 20px}.tabs{display:flex;gap:8px;margin-bottom:24px;flex-wrap:wrap}.tab{background:transparent;border:1.5px solid var(--muted);color:var(--primary);border-radius:10px;padding:10px 18px;font-weight:600;font-size:15px;font-family:inherit;cursor:pointer;min-height:44px}.tab.on{background:var(--primary);color:var(--bg);border-color:var(--primary)}.prose{display:flex;flex-direction:column;gap:14px;font-size:17px;line-height:1.7}.prose h2{font-size:22px;margin-top:12px}.prose p,.prose ol,.prose ul{margin:0}.prose li{margin:4px 0}.prose blockquote{margin:0;padding:12px 16px;background:var(--raised);border-left:4px solid var(--accent);border-radius:8px}.prose code,.bubble code{font-family:IBM Plex Mono,monospace;font-size:.88em;background:var(--raised);padding:2px 6px;border-radius:6px}.takeaways{background:var(--accent);border-color:var(--accent)}.takeaways ul{margin:8px 0 0;padding-left:20px}.code{background:var(--code);border-radius:14px;padding:20px;overflow-x:auto;margin:0}.prose .code code{background:none;padding:0;color:var(--code-text);font-size:14px;line-height:1.7}.quiz{display:flex;flex-direction:column;gap:16px}fieldset{margin:0;border:1px solid var(--line);background:var(--surface);border-radius:var(--radius);padding:20px}legend{font-weight:800;padding:0 8px}.opt{flex-direction:row;align-items:center;gap:10px;padding:10px 12px;border-radius:10px;font-weight:400;cursor:pointer}.opt:hover{background:var(--raised)}.opt.right{background:#4f7a4a33}.opt.wrong{background:#a5443f29}.result,.finish{display:flex;justify-content:space-between;align-items:center;gap:12px;flex-wrap:wrap;background:var(--accent);border-color:var(--accent)}.finish{margin-top:18px;flex-direction:column;align-items:flex-start}.finish p{margin:0}.pager{display:flex;justify-content:space-between;gap:12px;margin-top:36px;padding-top:20px;border-top:1px solid var(--line);flex-wrap:wrap}.tutor{border-left:1px solid var(--line);padding:24px 18px;display:flex;flex-direction:column;gap:12px;background:var(--surface);height:calc(100vh - 72px);position:sticky;top:72px}.tutor h2{font-size:18px}.chat{flex:1;overflow-y:auto;display:flex;flex-direction:column;gap:10px}.bubble{padding:12px 14px;border-radius:14px;font-size:14px;max-width:92%}.bubble p{margin:0 0 8px}.bubble p:last-child{margin:0}.bubble.assistant{background:var(--raised)}.bubble.user{background:var(--primary);color:var(--bg);align-self:flex-end}.chat-form{display:flex;gap:8px}.chat-form input{flex:1;min-width:0}.foot{padding:28px 32px;text-align:center;color:var(--text-soft);font-size:13px;border-top:1px solid var(--line)}@media (max-width:1100px){.lesson-layout{grid-template-columns:1fr}.side{flex-direction:row;overflow-x:auto;border-right:0;border-bottom:1px solid var(--line);padding:14px}.side-title{display:none}.side a:not(.side-title){white-space:nowrap}.tutor{position:static;height:480px;border-left:0;border-top:1px solid var(--line)}.lesson{padding:28px 20px}}@media (max-width:800px){.hero{grid-template-columns:1fr}.nav{padding:0 16px}.page{padding:24px 16px 48px}}