:root{--bg:#0d1016;--surface:#151a22;--surface-2:#1c222c;--border:#29303b;--text:#e7eaf0;--muted:#98a2b3;--accent:#6d97ff;--accent-strong:#4f7dfa;--on-accent:#fff;--ok:#3ecf8e;--ko:#ff6b6b;--lv1:#3ecf8e;--lv2:#5aa9ff;--lv3:#b18cff;--lv4:#ffb454;--code-bg:#0a0d12;--code-text:#d6dbe4;--tok-keyword:#c792ea;--tok-string:#a5d6a7;--tok-number:#f78c6c;--tok-comment:#6b7686;--tok-title:#82aaff;--tok-attr:#ffcb6b;--tok-tag:#f07178;--shadow:0 10px 30px #00000059;--radius:14px;--mono:ui-monospace, "Cascadia Code", "SF Mono", Consolas, "Liberation Mono", monospace;--sans:system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", sans-serif;--lightningcss-light: ;--lightningcss-dark:initial;color-scheme:dark}:root[data-theme=light]{--bg:#f5f6f8;--surface:#fff;--surface-2:#eef0f4;--border:#dde1e8;--text:#171b22;--muted:#5a6475;--accent:#2f5fe0;--accent-strong:#2450c8;--ok:#128a5a;--ko:#d03b3b;--lv1:#128a5a;--lv2:#1f6fd1;--lv3:#7446d6;--lv4:#b86a00;--code-bg:#f3f4f7;--code-text:#232833;--tok-keyword:#8431c5;--tok-string:#1f7a3d;--tok-number:#b3470f;--tok-comment:#7b8494;--tok-title:#1d5fc4;--tok-attr:#99600a;--tok-tag:#c0323c;--shadow:0 10px 30px #141e3c14;--lightningcss-light:initial;--lightningcss-dark: ;color-scheme:light}*,:before,:after{box-sizing:border-box}html{scroll-padding-top:80px}body{background:var(--bg);color:var(--text);font-family:var(--sans);-webkit-font-smoothing:antialiased;margin:0;font-size:16px;line-height:1.6}h1,h2,h3{letter-spacing:-.02em;text-wrap:balance;margin:0;line-height:1.2}p{margin:0}a{color:var(--accent);text-decoration:none}button,input,textarea{font:inherit;color:inherit}code,pre,textarea,.log{font-variant-ligatures:none}button{cursor:pointer}:focus-visible{outline:2px solid var(--accent);outline-offset:2px}.muted{color:var(--muted)}.center{text-align:center}.eyebrow{font-family:var(--mono);letter-spacing:.04em;text-transform:uppercase;color:var(--muted);font-size:12.5px}.app{flex-direction:column;min-height:100vh;display:flex}.topbar{z-index:20;background:color-mix(in srgb, var(--bg) 85%, transparent);-webkit-backdrop-filter:blur(12px);backdrop-filter:blur(12px);border-bottom:1px solid var(--border);position:sticky;top:0}.topbar-inner{align-items:center;gap:24px;max-width:1240px;margin:0 auto;padding:10px 20px;display:flex}.brand{color:var(--text);letter-spacing:-.02em;align-items:center;gap:10px;font-size:18px;font-weight:700;display:flex}.brand-mark{background:var(--accent-strong);width:34px;height:34px;color:var(--on-accent);font-family:var(--mono);border-radius:9px;place-items:center;font-size:12px;font-weight:700;display:grid}.nav{flex:1;gap:4px;display:flex}.nav a{color:var(--muted);border-radius:8px;padding:6px 12px;font-size:15px;font-weight:500}.nav a:hover,.nav a.active{color:var(--text);background:var(--surface-2)}.topbar-right{align-items:center;gap:10px;display:flex}.progress-pill{border:1px solid var(--border);color:var(--text);font-size:13px;font-family:var(--mono);font-variant-numeric:tabular-nums;border-radius:999px;align-items:center;gap:8px;padding:6px 12px;display:flex}.progress-pill-bar{background:var(--surface-2);border-radius:999px;width:56px;height:6px;overflow:hidden}.progress-pill-bar span{background:var(--ok);border-radius:inherit;height:100%;transition:width .4s;display:block}.icon-btn{border:1px solid var(--border);background:0 0;border-radius:9px;width:36px;height:36px;font-size:16px}.icon-btn:hover{background:var(--surface-2)}.main{flex:1;width:100%}.page{flex-direction:column;gap:48px;max-width:1040px;margin:0 auto;padding:40px 20px 64px;display:flex}.page-wide{gap:24px;max-width:1400px}.footer{border-top:1px solid var(--border);text-align:center;color:var(--muted);padding:20px;font-size:13px}.btn{white-space:nowrap;border:1px solid #0000;border-radius:10px;justify-content:center;align-items:center;gap:8px;padding:9px 16px;font-size:15px;font-weight:600;transition:background .15s,border-color .15s,transform 50ms;display:inline-flex}.btn:active{transform:translateY(1px)}.btn.lg{padding:13px 22px;font-size:16px}.btn.primary{background:var(--accent-strong);color:var(--on-accent)}.btn.primary:hover{background:var(--accent)}:root[data-theme=light] .btn.primary:hover{background:#1c44b3}.btn.ghost{border-color:var(--border);color:var(--text);background:0 0}.btn.ghost:hover{background:var(--surface-2)}.btn.danger{color:var(--ko)}.btn.sm{padding:6px 12px;font-size:14px}.btn:disabled{opacity:.6;cursor:default}.user{align-items:center;gap:8px;display:flex}.avatar{background:color-mix(in srgb, var(--accent) 22%, transparent);width:34px;height:34px;color:var(--accent);border-radius:50%;place-items:center;font-size:14px;font-weight:700;display:grid}.save-error{text-align:center;color:var(--ko);background:color-mix(in srgb, var(--ko) 10%, var(--bg));border-top:1px solid var(--border);padding:8px 20px;font-size:14px}.auth-page{align-items:center}.auth-card{border:1px solid var(--border);border-radius:var(--radius);background:var(--surface);flex-direction:column;gap:18px;width:100%;max-width:420px;padding:28px;display:flex}.auth-card h1{margin-bottom:6px;font-size:28px}.field{flex-direction:column;gap:6px;display:flex}.field label{font-size:14.5px;font-weight:600}.field input{border:1px solid var(--border);background:var(--bg);border-radius:10px;padding:11px 13px}.field small{font-size:13px}.auth-note,.auth-error{border-radius:10px;padding:10px 13px;font-size:14.5px}.auth-note{background:color-mix(in srgb, var(--ok) 10%, var(--bg));border:1px solid color-mix(in srgb, var(--ok) 35%, transparent)}.auth-error{color:var(--ko);background:color-mix(in srgb, var(--ko) 10%, var(--bg));border:1px solid color-mix(in srgb, var(--ko) 35%, transparent)}.hero{flex-direction:column;align-items:flex-start;gap:20px;padding:40px 0 8px;display:flex}.hero h1{letter-spacing:-.04em;font-size:clamp(40px,7vw,72px);font-weight:800;line-height:1.02}.grad{background:linear-gradient(90deg, var(--lv1), var(--lv2) 40%, var(--lv3) 70%, var(--lv4));color:#0000;-webkit-background-clip:text;background-clip:text}.lead{color:var(--muted);max-width:62ch;font-size:19px}.hero-actions{flex-wrap:wrap;gap:12px;margin-top:8px;display:flex}.hero-next{color:var(--muted);font-size:15px}.hero-next strong{color:var(--text)}.stats{border:1px solid var(--border);border-radius:var(--radius);background:var(--surface);grid-template-columns:repeat(4,1fr);display:grid;overflow:hidden}.stat{border-left:1px solid var(--border);flex-direction:column;gap:2px;padding:20px 22px;display:flex}.stat:first-child{border-left:0}.stat b{letter-spacing:-.03em;font-variant-numeric:tabular-nums;font-size:30px;font-weight:700;line-height:1.2}.stat b.stat-text{letter-spacing:-.02em;font-size:20px;line-height:1.8}.stat small{color:var(--muted);letter-spacing:0;font-size:15px;font-weight:500}.stat span{color:var(--muted);font-size:14px}.section-title{margin-bottom:20px;font-size:26px}.level-grid{grid-template-columns:repeat(2,1fr);gap:16px;display:grid}.level-card{border:1px solid var(--border);border-top:3px solid var(--lv);border-radius:var(--radius);background:var(--surface);color:var(--text);flex-direction:column;gap:10px;padding:22px;transition:transform .15s,box-shadow .15s;display:flex}.level-card:hover{box-shadow:var(--shadow);transform:translateY(-2px)}.level-num{font-family:var(--mono);text-transform:uppercase;letter-spacing:.06em;color:var(--lv);font-size:12px;font-weight:600}.level-card h3{font-size:22px}.level-card p{color:var(--muted);font-size:15px}.chips{flex-wrap:wrap;gap:6px;margin:4px 0 8px;display:flex}.chip{font-family:var(--mono);background:var(--surface-2);color:var(--muted);border-radius:6px;padding:3px 8px;font-size:11.5px}.bar{background:var(--surface-2);border-radius:999px;height:6px;overflow:hidden}.bar span{border-radius:inherit;background:var(--lv,var(--accent));height:100%;transition:width .4s;display:block}.bar-label{color:var(--muted);font-size:13px}.how-grid{grid-template-columns:repeat(3,1fr);gap:16px;margin-bottom:24px;display:grid}.how{border-radius:var(--radius);background:var(--surface);border:1px solid var(--border);padding:22px}.how span{font-family:var(--mono);color:var(--accent);font-size:13px}.how h3{margin:8px 0 6px;font-size:18px}.how p{color:var(--muted);font-size:15px}.page-head{flex-wrap:wrap;justify-content:space-between;align-items:flex-end;gap:20px;display:flex}.page-head h1{margin-bottom:6px;font-size:36px}.page-head p{max-width:60ch}.search{border:1px solid var(--border);background:var(--surface);border-radius:10px;width:260px;max-width:100%;padding:10px 14px}.empty{text-align:center;color:var(--muted);border:1px dashed var(--border);border-radius:var(--radius);padding:40px}.level-section{flex-direction:column;gap:16px;display:flex}.level-head{border-left:3px solid var(--lv);padding-left:16px}.level-head h2{margin:2px 0 4px;font-size:28px}.level-head p{color:var(--muted)}.module-list{flex-direction:column;gap:14px;display:flex}.module{border:1px solid var(--border);border-radius:var(--radius);background:var(--surface);overflow:hidden}.module-head{align-items:center;gap:16px;padding:18px 20px;display:flex}.badge{min-width:52px;height:40px;font-family:var(--mono);color:var(--lv);background:color-mix(in srgb, var(--lv) 14%, transparent);border:1px solid color-mix(in srgb, var(--lv) 35%, transparent);border-radius:10px;flex:none;place-items:center;padding:0 8px;font-size:12.5px;font-weight:700;display:grid}.module-info{flex:1;min-width:0}.module-info h3{font-size:18px}.module-info p{color:var(--muted);font-size:14.5px}.module-progress{width:110px;font-family:var(--mono);color:var(--muted);flex-direction:column;flex:none;align-items:flex-end;gap:6px;font-size:13px;display:flex}.module-progress .bar{width:100%}.lesson-list{border-top:1px solid var(--border);margin:0;padding:0;list-style:none}.lesson-list li+li{border-top:1px solid var(--border)}.lesson-list a{color:var(--text);align-items:center;gap:14px;padding:11px 20px;display:flex}.lesson-list a:hover{background:var(--surface-2)}.check{border:1.5px solid var(--border);width:24px;height:24px;font-size:12px;font-family:var(--mono);color:var(--muted);border-radius:50%;flex:none;place-items:center;display:grid}.done .check{background:var(--ok);border-color:var(--ok);color:var(--bg);font-weight:700}.lesson-title{flex:1}.lesson-min{color:var(--muted);font-size:13px;font-family:var(--mono)}.lesson-layout{grid-template-columns:260px minmax(0,1fr);align-items:start;gap:48px;max-width:1240px;margin:0 auto;padding:32px 20px 64px;display:grid}.lesson-side{flex-direction:column;gap:16px;font-size:14.5px;display:flex;position:sticky;top:84px}.back{color:var(--muted);font-size:14px}.back:hover{color:var(--text)}.side-module{align-items:center;gap:12px;display:flex}.side-module small{color:var(--lv);font-family:var(--mono);text-transform:uppercase;letter-spacing:.05em;font-size:11.5px;display:block}.side-module strong{line-height:1.25;display:block}.side-list{flex-direction:column;gap:2px;margin:0;padding:0;list-style:none;display:flex}.side-list a{color:var(--muted);border-radius:9px;align-items:center;gap:10px;padding:8px 10px;line-height:1.3;display:flex}.side-list a:hover{background:var(--surface-2);color:var(--text)}.side-list a.current{background:var(--surface-2);color:var(--text);font-weight:600}.lesson{width:100%;min-width:0;max-width:800px}.lesson-head{margin-bottom:28px}.lesson-head h1{letter-spacing:-.03em;margin-top:10px;font-size:clamp(30px,4.5vw,42px)}.done-tag{color:var(--ok);text-transform:none;letter-spacing:0;margin-left:12px}.prose{font-size:17px;line-height:1.7}.prose>*+*{margin-top:18px}.prose h2{margin-top:40px;font-size:25px}.prose h3{margin-top:28px;font-size:19px}.prose ul,.prose ol{margin-bottom:0;padding-left:24px}.prose li+li{margin-top:6px}.prose li::marker{color:var(--muted)}.prose a{text-underline-offset:3px;text-decoration:underline}.prose :not(pre)>code,.quiz :not(pre)>code{font-family:var(--mono);background:var(--surface-2);border:1px solid var(--border);overflow-wrap:anywhere;border-radius:6px;padding:2px 6px;font-size:.88em}.note{border-left:3px solid var(--lv,var(--accent));background:color-mix(in srgb, var(--lv,var(--accent)) 9%, var(--surface));border-radius:12px;padding:14px 18px;font-size:16px}.code{border:1px solid var(--border);background:var(--code-bg);border-radius:12px;margin:18px 0 0;overflow:hidden}.code figcaption{border-bottom:1px solid var(--border);font-family:var(--mono);color:var(--muted);justify-content:space-between;align-items:center;padding:6px 8px 6px 14px;font-size:12px;display:flex}.code figcaption button{color:var(--muted);font-size:12px;font-family:var(--sans);background:0 0;border:0;border-radius:6px;padding:4px 8px}.code figcaption button:hover{background:var(--surface-2);color:var(--text)}.code pre{font-family:var(--mono);color:var(--code-text);tab-size:2;margin:0;padding:14px 16px;font-size:14px;line-height:1.6;overflow-x:auto}.code code{font-family:inherit}.hljs-keyword,.hljs-literal,.hljs-built_in,.hljs-type,.hljs-selector-pseudo{color:var(--tok-keyword)}.hljs-string,.hljs-regexp,.hljs-addition{color:var(--tok-string)}.hljs-number,.hljs-symbol{color:var(--tok-number)}.hljs-comment,.hljs-quote,.hljs-meta{color:var(--tok-comment);font-style:italic}.hljs-title,.hljs-section,.hljs-selector-class,.hljs-selector-id{color:var(--tok-title)}.hljs-attr,.hljs-attribute,.hljs-property,.hljs-variable,.hljs-params{color:var(--tok-attr)}.hljs-params{color:var(--code-text)}.hljs-tag,.hljs-name,.hljs-selector-tag,.hljs-deletion{color:var(--tok-tag)}.lesson-playground{margin-top:28px}.lesson-playground .eyebrow{color:var(--lv);margin-bottom:10px}.pg{border:1px solid var(--border);border-radius:var(--radius);background:var(--surface);grid-template-columns:minmax(0,1fr) minmax(0,1fr);height:420px;display:grid;overflow:hidden}.pg-tall{height:calc(100vh - 230px);min-height:460px}.pg-editor{border-right:1px solid var(--border);flex-direction:column;min-width:0;min-height:0;display:flex}.pg-bar{border-bottom:1px solid var(--border);flex-wrap:wrap;justify-content:space-between;align-items:center;gap:8px;padding:6px 8px;display:flex}.pg-tabs,.pg-actions{gap:4px;display:flex}.pg-bar button{color:var(--muted);background:0 0;border:0;border-radius:7px;align-items:center;gap:6px;padding:5px 10px;font-size:13px;font-weight:500;display:inline-flex}.pg-bar button:hover,.pg-bar button.active{background:var(--surface-2);color:var(--text)}.pg-bar button.primary{background:var(--accent-strong);color:var(--on-accent)}.pg-bar .dot{background:var(--ok);border-radius:50%;width:6px;height:6px}.pg textarea{resize:none;background:var(--code-bg);width:100%;min-height:0;color:var(--code-text);font-family:var(--mono);tab-size:2;white-space:pre;border:0;outline:0;flex:1;padding:14px 16px;font-size:14px;line-height:1.6;overflow:auto}.pg-output{grid-template-rows:minmax(0,1.7fr) minmax(0,1fr);min-width:0;min-height:0;display:grid}.pg-preview,.pg-console{flex-direction:column;min-height:0;display:flex}.pg-console{border-top:1px solid var(--border)}.pg-label{font-family:var(--mono);text-transform:uppercase;letter-spacing:.06em;color:var(--muted);border-bottom:1px solid var(--border);padding:6px 12px;font-size:11.5px}.pg iframe{background:#fff;border:0;flex:1;width:100%;min-height:0}.pg-logs{font-family:var(--mono);background:var(--code-bg);flex:1;font-size:13px;overflow:auto}.pg-empty{color:var(--muted);padding:10px 12px}.log{border-bottom:1px solid var(--border);white-space:pre-wrap;overflow-wrap:anywhere;color:var(--code-text);padding:5px 12px}.log-warn{color:var(--lv4)}.log-error{color:var(--ko)}.pg-console-only{height:380px}.pg-console-only .pg-output{grid-template-rows:minmax(0,1fr)}.pg-console-only .pg-preview{display:none}.pg-console-only .pg-console{border-top:0}.quiz{border:1px solid var(--border);border-radius:var(--radius);background:var(--surface);flex-direction:column;align-items:stretch;gap:24px;margin-top:48px;padding:24px;display:flex}.quiz-head{flex-wrap:wrap;justify-content:space-between;align-items:baseline;gap:12px;display:flex}.quiz-head h2{font-size:22px}.quiz-score{font-family:var(--mono);color:var(--muted);font-size:13px}.question{border:0;min-width:0;margin:0;padding:0}.question legend{gap:12px;margin-bottom:12px;padding:0;font-size:17px;font-weight:600;display:flex}.q-num{font-family:var(--mono);color:var(--lv,var(--accent));flex:none}.options{gap:8px;display:grid}.option{text-align:left;border:1px solid var(--border);background:var(--bg);border-radius:10px;align-items:flex-start;gap:12px;padding:10px 14px;line-height:1.45;display:flex}.option:not(:disabled):hover{border-color:var(--accent)}.option:disabled{cursor:default;opacity:.65}.option-mark{width:22px;font-family:var(--mono);color:var(--muted);flex:none;font-size:13px;line-height:1.75}.option.correct{opacity:1;border-color:var(--ok);background:color-mix(in srgb, var(--ok) 12%, var(--bg))}.option.correct .option-mark{color:var(--ok);font-weight:700}.option.wrong{opacity:1;border-color:var(--ko);background:color-mix(in srgb, var(--ko) 10%, var(--bg))}.option.wrong .option-mark{color:var(--ko);font-weight:700}.feedback{color:var(--muted);margin-top:10px;font-size:15px}.feedback.ok strong{color:var(--ok)}.feedback.ko strong{color:var(--ko)}.quiz>.btn{align-self:flex-start}.lesson-foot{flex-direction:column;gap:12px;margin-top:32px;display:flex}.lesson-nav{flex-wrap:wrap;justify-content:space-between;gap:12px;display:flex}.lesson-nav-right{flex-wrap:wrap;gap:10px;display:flex}.next-hint{text-align:right;font-size:14px}.next-hint strong{color:var(--text)}.glossary{grid-template-columns:repeat(2,1fr);gap:12px;margin:0;display:grid}.term{border:1px solid var(--border);background:var(--surface);border-radius:12px;padding:16px 18px}.term dt{margin-bottom:4px;font-weight:700}.term dd{color:var(--muted);margin:0;font-size:15px}@media (width<=900px){.lesson-layout{grid-template-columns:minmax(0,1fr);gap:24px}.lesson-side{position:static}.side-list{display:none}.pg,.pg-tall{grid-template-columns:minmax(0,1fr);height:auto}.pg-editor{border-right:0;border-bottom:1px solid var(--border)}.pg textarea{flex:none;height:260px}.pg-output{grid-template-rows:260px 150px}.pg-console-only .pg-output{grid-template-rows:180px}}@media (width<=720px){.topbar-inner{flex-wrap:wrap;gap:8px 12px}.nav{flex-basis:100%;order:3;overflow-x:auto}.topbar-right{margin-left:auto}.stats{grid-template-columns:repeat(2,1fr)}.stat:nth-child(3){border-left:0}.stat:nth-child(n+3){border-top:1px solid var(--border)}.level-grid,.how-grid,.glossary{grid-template-columns:minmax(0,1fr)}.module-head{flex-wrap:wrap}.module-progress{flex-direction:row;align-items:center;width:100%}.page{gap:36px;padding-top:28px}.quiz{padding:18px}}@media (prefers-reduced-motion:reduce){*{transition:none!important}}