:root{--bg:#090c12;--panel:#111722;--panel2:#151d2a;--text:#eef2f8;--muted:#95a2b6;--line:#253044;--lime:#b8f34a;--cyan:#52d9e8;--red:#ff6b79;--max:1180px;font-family:Inter,ui-sans-serif,system-ui,-apple-system,sans-serif;color-scheme:dark}
*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;background:radial-gradient(circle at 85% 5%,#152237 0,transparent 25rem),var(--bg);color:var(--text);min-height:100vh}a{color:inherit;text-decoration:none}button,input{font:inherit}main{width:min(var(--max),calc(100% - 2rem));margin:auto;min-height:calc(100vh - 10rem)}
.topbar{height:72px;width:min(var(--max),calc(100% - 2rem));margin:auto;display:flex;align-items:center;justify-content:space-between;border-bottom:1px solid var(--line)}.brand{font-weight:800;letter-spacing:-.02em;display:flex;gap:.65rem;align-items:center}.brand-mark{display:grid;place-items:center;width:29px;height:29px;background:var(--lime);color:#0b0f14;border-radius:8px;box-shadow:0 0 25px #b8f34a33}.topbar nav{display:flex;align-items:center;gap:1.4rem;font-size:.9rem;color:var(--muted)}.topbar a:hover,.link-button:hover{color:var(--text)}.inline{display:inline}.link-button{border:0;background:none;color:var(--muted);cursor:pointer;padding:0}
.button{display:inline-flex;align-items:center;justify-content:center;border:1px solid var(--lime);background:var(--lime);color:#0b0e13;font-weight:750;padding:.8rem 1.15rem;border-radius:8px;cursor:pointer;transition:.15s transform,.15s box-shadow}.button:hover{transform:translateY(-1px);box-shadow:0 7px 24px #b8f34a22}.button.ghost{background:transparent;color:var(--text);border-color:var(--line)}.button.small{padding:.48rem .75rem;font-size:.84rem}
.hero{min-height:590px;display:grid;grid-template-columns:1.05fr .95fr;gap:5rem;align-items:center}.eyebrow{text-transform:uppercase;letter-spacing:.17em;color:var(--lime);font-size:.72rem;font-weight:800;margin:0 0 1rem}.hero h1,.page-head h1,.auth-copy h1{font-size:clamp(3rem,7vw,5.7rem);line-height:.96;letter-spacing:-.065em;margin:0}.hero h1 span{color:var(--muted)}.lede,.page-head>p:last-child,.auth-copy>p:last-child{font-size:1.08rem;line-height:1.7;color:var(--muted);max-width:650px}.actions{display:flex;gap:.75rem;margin-top:2rem}
.terminal{background:#0b111b;border:1px solid #2b374a;border-radius:13px;box-shadow:0 28px 80px #0009;overflow:hidden;transform:perspective(900px) rotateY(-2deg)}.terminal-bar{height:42px;border-bottom:1px solid var(--line);display:flex;align-items:center;gap:.4rem;padding:0 .8rem}.terminal-bar i{width:9px;height:9px;border-radius:50%;background:#354154}.terminal-bar i:first-child{background:var(--red)}.terminal-bar span{margin:auto;color:#69778b;font:11px ui-monospace}.terminal pre{padding:1.5rem 1.8rem;line-height:1.8;color:#9daabd;min-height:260px;white-space:pre-wrap}.terminal em{color:var(--cyan);font-style:normal}.terminal strong{color:#ffd479}.terminal b{color:var(--lime)}
.metrics{display:grid;grid-template-columns:repeat(3,1fr);border-top:1px solid var(--line);border-bottom:1px solid var(--line);padding:2rem 0}.metrics div{display:flex;gap:1rem;justify-content:center;align-items:baseline}.metrics strong{font-size:2.5rem;color:var(--lime)}.metrics span{color:var(--muted)}.feature-grid,.module-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:1px;background:var(--line);border:1px solid var(--line);margin:5rem 0}.feature-grid article,.module-card{background:var(--bg);padding:2rem}.feature-grid article>span,.card-meta{color:var(--muted);font:12px ui-monospace}.feature-grid h2,.module-card h2{font-size:1.25rem}.feature-grid p,.module-card p{color:var(--muted);line-height:1.6}.page-head{padding:6rem 0 2rem}.page-head h1,.auth-copy h1{font-size:clamp(2.8rem,6vw,5rem);max-width:850px}.module-grid{grid-template-columns:repeat(4,1fr);margin-top:2rem}.module-card{min-height:260px;display:flex;flex-direction:column}.card-meta{display:flex;justify-content:space-between}.module-card .tag{color:var(--lime);font-size:.72rem;text-transform:uppercase;letter-spacing:.12em;margin-top:3rem}.module-card a{margin-top:auto;color:var(--cyan);font-weight:700}.compact .module-card{min-height:220px}
.auth-shell{min-height:calc(100vh - 9rem);display:grid;grid-template-columns:1fr 430px;gap:6rem;align-items:center}.panel{background:linear-gradient(145deg,var(--panel2),var(--panel));border:1px solid var(--line);border-radius:11px;padding:1.4rem;box-shadow:0 16px 45px #0004}.auth-form,.exercise-form{display:grid;gap:1rem}.auth-form label,.exercise-form label{display:grid;gap:.45rem;color:var(--muted);font-size:.8rem;font-weight:700}.auth-form input,.exercise-form input,.row input{border:1px solid #334056;background:#0c111a;color:var(--text);padding:.8rem;border-radius:7px;outline:none}.auth-form input:focus,.exercise-form input:focus,.row input:focus{border-color:var(--cyan);box-shadow:0 0 0 3px #52d9e819}.muted{color:var(--muted);font-size:.85rem}.muted a{color:var(--cyan)}
.account-head{padding-bottom:1rem}.progress-banner{display:flex;align-items:center;gap:2rem;background:var(--panel);border:1px solid var(--line);padding:1.3rem;border-radius:10px}.progress-banner div:first-child{display:flex;gap:.65rem;align-items:baseline;white-space:nowrap}.progress-banner strong{font-size:2rem;color:var(--lime)}.progress-banner span{color:var(--muted)}.progress-banner progress{height:7px;flex:1;border:0;border-radius:5px;overflow:hidden;background:#222d3d}.progress-banner progress::-webkit-progress-bar{background:#222d3d}.progress-banner progress::-webkit-progress-value{background:linear-gradient(90deg,var(--lime),var(--cyan))}.progress-banner progress::-moz-progress-bar{background:linear-gradient(90deg,var(--lime),var(--cyan))}
.lesson-head{display:flex;justify-content:space-between;align-items:end;padding:3.2rem 0 1.5rem}.lesson-head h1{font-size:2.8rem;letter-spacing:-.04em;margin:.2rem 0}.lesson-head p:last-child{color:var(--muted)}.phase-nav{display:grid;grid-template-columns:repeat(4,1fr);border:1px solid var(--line);border-radius:9px;overflow:hidden;margin-bottom:1.5rem}.phase-nav a{padding:.9rem;background:var(--panel);color:var(--muted);border-right:1px solid var(--line);font-size:.85rem}.phase-nav a:last-child{border:0}.phase-nav a.active{background:#202b3b;color:var(--text);box-shadow:inset 0 -2px var(--lime)}.phase-nav span{display:inline-grid;place-items:center;width:22px;height:22px;border:1px solid var(--line);border-radius:50%;margin-right:.55rem;font:11px ui-monospace}.phase-nav .active span{border-color:var(--lime);color:var(--lime)}
.lesson-layout{display:grid;grid-template-columns:minmax(0,1.15fr) minmax(350px,.85fr);gap:1.2rem;padding-bottom:5rem}.workspace,.lesson-layout aside{display:grid;gap:1rem;align-content:start}.panel-title{display:flex;align-items:center;justify-content:space-between;margin-bottom:1rem;color:var(--muted);font-size:.8rem;text-transform:uppercase;letter-spacing:.08em}.panel-title code{color:var(--lime)}.exercise-form{grid-template-columns:repeat(2,1fr)}.exercise-form label:only-of-type,.exercise-form button{grid-column:1/-1}.result{border-color:#37445a}.result.success{border-color:#709934}.result pre,.oob-panel pre{white-space:pre-wrap;background:#090d14;padding:1rem;border-radius:7px;color:#cad2df}.result strong{color:var(--lime);font-size:.72rem}.result ol{padding-left:1.3rem;color:var(--muted)}.result iframe{border:1px solid var(--line);width:100%;min-height:180px;border-radius:7px;background:#111827}
details,.source-card{border:1px solid var(--line);background:var(--panel);border-radius:9px;padding:1rem}summary{cursor:pointer;font-weight:700}details p{color:var(--muted);line-height:1.6}.source-card{padding:0;overflow:hidden}.source-card .panel-title{padding:.8rem 1rem;margin:0;border-bottom:1px solid var(--line)}pre.source{margin:0;padding:1rem;overflow:auto;font:12px/1.75 ui-monospace;color:#cad4e2}.source span{display:block;white-space:pre}.source b{display:inline-block;width:2.7rem;color:#526076;font-weight:400;user-select:none}.diff pre{white-space:pre-wrap;overflow-wrap:anywhere;font-size:11px;color:#aebaca}.row{display:flex;gap:.55rem;margin:.8rem 0}.row input{min-width:0;flex:1}footer{width:min(var(--max),calc(100% - 2rem));border-top:1px solid var(--line);margin:auto;padding:2rem 0;color:var(--muted);font-size:.8rem}
@media(max-width:900px){.hero,.auth-shell,.lesson-layout{grid-template-columns:1fr}.hero{gap:2rem;padding:5rem 0}.module-grid{grid-template-columns:repeat(2,1fr)}.feature-grid{grid-template-columns:1fr}.auth-shell{gap:2rem;padding:5rem 0}.lesson-head{align-items:start}.topbar nav>a:first-child{display:none}}@media(max-width:590px){.module-grid{grid-template-columns:1fr}.metrics{grid-template-columns:1fr;gap:1rem}.topbar nav{gap:.7rem}.phase-nav a{font-size:0;text-align:center}.phase-nav span{font-size:11px;margin:0}.lesson-head{display:block}.lesson-head form{margin-top:1rem}.exercise-form{grid-template-columns:1fr}.row{flex-direction:column}}