:root{--ink:#18332f;--muted:#65736c;--paper:#f6f7f1;--line:#dce3d8;--green:#d2e8be;--accent:#225c47;--white:#fff;--orange:#ad592d}*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:90px}body{margin:0;background:var(--paper);color:var(--ink);font:16px/1.7 system-ui,-apple-system,"Segoe UI",sans-serif}a{color:var(--accent);text-underline-offset:4px}button,input,select{font:inherit}button,.button{border:1px solid var(--ink);background:var(--ink);color:white;border-radius:8px;padding:10px 17px;font-size:14px;font-weight:650;cursor:pointer;text-decoration:none;display:inline-block}button:hover,.button:hover{filter:brightness(1.16)}button:disabled{opacity:.5;cursor:default}.secondary{background:transparent;color:var(--ink);border-color:#acbbb0}.text-button{background:none;border:0;color:var(--ink);padding:5px}.danger{color:#ab3025}button:focus-visible,a:focus-visible,input:focus-visible,summary:focus-visible{outline:3px solid #cf8b30;outline-offset:4px}h1,h2,h3,h4{line-height:1.2;letter-spacing:-.035em}h1{font-size:clamp(34px,4.2vw,60px);font-weight:650;margin:18px 0 24px}h2{font-size:29px;margin:36px 0 17px}h3{font-size:21px}p{margin:0 0 19px}.topbar{height:82px;display:flex;align-items:center;justify-content:space-between;padding:0 34px;border-bottom:1px solid var(--line);background:rgba(246,247,241,.96);position:sticky;top:0;z-index:10;gap:24px}.brand{display:flex;align-items:center;gap:12px;text-decoration:none;color:var(--ink);font-size:12px;letter-spacing:.1em;white-space:nowrap}.brand b{display:block;font-size:11px;letter-spacing:.23em}.brand-mark{display:grid;place-items:center;width:42px;height:42px;background:var(--ink);color:#d2e8be;border-radius:10px;font:700 23px monospace}.topbar nav{display:flex;align-items:center;gap:25px;font-size:13px}.topbar nav a{text-decoration:none;color:var(--ink)}.layout{display:grid;grid-template-columns:270px 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span{display:block;height:100%;background:var(--accent)}main{padding:48px clamp(24px,4.5vw,72px) 70px;min-width:0}.eyebrow{font-size:11px;letter-spacing:.19em;text-transform:uppercase;color:var(--muted);font-weight:700}.hero{display:grid;grid-template-columns:1.25fr 1fr;gap:30px;align-items:center;padding-bottom:38px;border-bottom:1px solid var(--line)}.hero p{color:var(--muted);max-width:590px;font-size:17px}.hero h1 span{color:#658356}.hero-terminal{background:var(--ink);border-radius:15px;padding:23px;color:#d9eccc;box-shadow:12px 14px 0 #e6eadf;transform:rotate(-1deg);font:13px/1.9 ui-monospace,SFMono-Regular,Consolas,monospace}.terminal-top{display:flex;justify-content:space-between;border-bottom:1px solid #456057;padding-bottom:16px;margin-bottom:22px;color:#a7b9ac;font-size:10px}.dots{letter-spacing:6px;color:#b4cc9e}.hero-terminal p{font:inherit;color:inherit;margin:5px 0}.hero-terminal .dim{color:#8ea99c}.hero-terminal .output{color:#cfe5bb;padding-left:14px}.hero-terminal 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.card-foot{margin-top:18px;display:flex;justify-content:space-between;align-items:center;font-size:12px}.tag{display:inline-block;font-size:10px;letter-spacing:.07em;text-transform:uppercase;border:1px solid #cbd6c4;border-radius:5px;padding:3px 8px;color:#52734e;width:fit-content}.module-card:last-child{background:#e5eedb}.button-row{display:flex;gap:10px;align-items:center;flex-wrap:wrap;margin:23px 0}.notice{background:#eaf0e0;border-left:3px solid #729c55;border-radius:0 8px 8px 0;padding:18px 22px;margin:25px 0;font-size:14px}.notice p:last-child{margin-bottom:0}.muted{color:var(--muted);font-size:13px}.lesson-header{border-bottom:1px solid var(--line);padding-bottom:23px;margin-bottom:28px}.lesson-header h1{font-size:clamp(30px,3.4vw,46px);max-width:920px}.meta{display:flex;gap:12px;flex-wrap:wrap;align-items:center;font-size:13px;color:var(--muted)}.lesson-nav{display:flex;gap:17px;flex-wrap:wrap;font-size:13px;margin-top:25px}.prose{max-width:850px}.prose h2{font-size:26px;margin-top:35px}.prose p{color:#334b42;font-size:16px;line-height:1.85}code{font:13px/1.6 ui-monospace,SFMono-Regular,Consolas,monospace;background:#e9eee2;padding:2px 5px;border-radius:3px;overflow-wrap:anywhere}pre{position:relative;background:#152b28;color:#e0eed6;border-radius:10px;padding:23px;overflow:auto;max-width:100%;white-space:pre;font:13px/1.8 ui-monospace,Consolas,monospace}pre code{background:none;color:inherit;padding:0;overflow-wrap:normal}.code-top{display:flex;justify-content:space-between;align-items:center;margin-bottom:-7px;font-size:11px;color:var(--muted)}.code-top button{font-size:11px;padding:3px 10px;background:transparent;color:var(--ink);border-color:var(--line)}.task-list{padding-left:25px}.task-list li{padding:6px 0}.check-list{padding-left:22px;font-size:14px;color:var(--muted)}.lesson-section{border-top:1px solid var(--line);padding-top:8px;margin-top:35px}.quiz{background:white;border:1px solid var(--line);padding:25px;border-radius:12px}.quiz fieldset{border:0;padding:0;margin:0 0 25px}.quiz legend{font-weight:650;margin-bottom:12px;line-height:1.5}.quiz label{display:flex;gap:10px;align-items:baseline;padding:9px 12px;border:1px solid var(--line);margin:6px 0;border-radius:7px;cursor:pointer;font-size:14px}.quiz label:has(input:checked){background:#edf4e5;border-color:#80a267}.quiz input{accent-color:var(--accent)}.quiz-result{padding-top:12px}.correct{color:#266440}.incorrect{color:#ae3f2b}details.answer{background:#edf0e6;border:1px solid var(--line);border-radius:9px;margin:14px 0;padding:16px 20px}details.answer summary{cursor:pointer;font-weight:600}details.answer p{margin-top:15px}details.answer pre{margin-bottom:0}.status-badge{font-size:12px;display:inline-block;padding:4px 10px;border-radius:20px;background:#e4ecd9;color:#36643c}.lesson-bottom{display:flex;justify-content:space-between;align-items:center;gap:12px;border-top:1px solid var(--line);padding-top:25px;margin-top:35px}.search-results a{display:block;background:white;padding:15px 20px;border:1px solid var(--line);margin:8px 0;text-decoration:none;border-radius:7px}.reference-grid{display:grid;grid-template-columns:1fr 1fr;gap:15px}.reference-card{background:white;border:1px solid var(--line);padding:20px;border-radius:10px}.reference-card h3{margin-top:0}.reference-card p{font-size:14px}.reference-card code{font-size:12px}.toc{display:flex;gap:8px;flex-wrap:wrap}.toc a{background:#e7eddf;border-radius:5px;padding:4px 10px;font-size:12px;text-decoration:none}footer{padding:25px 35px;border-top:1px solid var(--line);font-size:11px;color:var(--muted);display:flex;justify-content:space-between}dialog{border:1px solid var(--line);border-radius:15px;max-width:560px;width:calc(100% - 35px);padding:30px;color:var(--ink);background:var(--paper)}dialog::backdrop{background:#0b241ecc}.dialog-head{display:flex;align-items:center;justify-content:space-between}.dialog-head h2{margin:0 0 20px}.dialog-head button{background:none;color:var(--ink);border:0}.skip{position:fixed;top:-60px;background:white;z-index:20;padding:10px}.skip:focus{top:5px}#toast{position:fixed;bottom:20px;right:20px;max-width:420px;background:var(--ink);color:white;border-radius:8px;padding:0;z-index:50;font-size:14px}#toast.visible{padding:14px 20px}.error{padding:25px;border:1px solid #c66;color:#932e25;border-radius:10px}.loading{color:var(--muted)}@media(max-width:1100px){.layout{grid-template-columns:225px minmax(0,1fr)}.sidebar{padding:23px 12px}.hero{grid-template-columns:1fr}.hero-terminal{display:none}.topbar{padding:0 22px}.topbar nav{gap:16px}.grid{gap:10px}.module-card{padding:20px}}@media(max-width:740px){.topbar{height:auto;min-height:80px;padding:15px 18px;align-items:flex-start;flex-wrap:wrap;gap:10px}.topbar nav{gap:15px;flex-wrap:wrap;font-size:12px}.topbar nav button{font-size:12px;padding:0}.brand b{display:inline;margin-left:7px}.brand-mark{width:32px;height:32px;font-size:19px}.layout{display:block}.sidebar{display:none}main{padding:30px 20px 50px}.hero h1{font-size:44px}.stats{grid-template-columns:1fr 1fr;gap:20px}.grid,.reference-grid{grid-template-columns:1fr}.stats strong{font-size:27px}.module-card{padding:22px}.section-title{align-items:flex-start}.section-title h2{font-size:26px}.quiz{padding:18px}pre{padding:17px;font-size:12px}.lesson-bottom{flex-wrap:wrap}footer{padding:20px;display:block}footer span{display:block;margin-top:5px}.button-row button,.button-row .button{font-size:13px}}@media print{.topbar,.sidebar,footer,button,.button,.lesson-nav,.lesson-bottom,.skip,#toast,dialog{display:none!important}.layout{display:block}main{padding:0}body{background:white;color:black}.prose{max-width:none}.lesson-header h1{font-size:30px}pre{white-space:pre-wrap;background:#eee;color:black;break-inside:avoid}.quiz{break-inside:avoid}details.answer:not([open]){display:none}}
.account-form{display:grid;gap:13px}.account-form label{display:grid;gap:5px;font-size:14px;font-weight:600}.account-form input{width:100%;padding:10px 12px;background:white;color:var(--ink);border:1px solid #bbc9b3;border-radius:7px}.account-form p{margin:0}.account-form button{margin-top:5px}.web-terminal{height:440px;background:#102723;border-radius:12px;padding:16px;overflow:hidden}.terminal-title{font-size:38px}.terminal-task{max-width:850px;margin-top:30px}.terminal-task li{padding:6px}.web-terminal .xterm{height:100%}#automatic-result{font-size:14px}#automatic-result pre{max-height:300px;white-space:pre-wrap}.source-note{font-size:12px;color:var(--muted);border-top:1px solid var(--line);padding-top:14px;margin-top:20px}.source-note a{margin-right:8px}.lesson-table{border-collapse:collapse;width:100%;font-size:14px;margin:20px 0}.lesson-table td,.lesson-table th{padding:10px;border:1px solid var(--line);text-align:left}.source-card{padding:20px;border:1px solid var(--line);border-radius:8px;background:white;margin:15px 0}@media(max-width:740px){.web-terminal{height:370px;padding:8px}.terminal-title{font-size:30px}}

/* xterm uses class="terminal" internally; hero styling must never target it. */
.inline-lab{margin:24px 0 30px;padding:0;border:1px solid #cbd6c4;border-radius:12px;overflow:hidden;background:#fff}
.inline-lab>.code-top{margin:0;padding:14px 18px;display:flex;align-items:center;gap:14px;background:#edf2e6;border-bottom:1px solid #cbd6c4;flex-wrap:wrap}
.inline-lab>.code-top strong{font-size:14px;letter-spacing:0;color:#18332f}
.inline-lab>.code-top span{font-size:12px;color:#65736c}
.inline-lab .web-terminal{height:420px;border-radius:0;margin:0;padding:14px 12px;transform:none;box-shadow:none;border:0}
.inline-lab>.button-row{margin:0;padding:12px 16px;border-bottom:1px solid #e0e7db;gap:16px;justify-content:flex-start}
.inline-lab>.button-row a{font-size:12px}
.inline-lab>.muted{margin:0;padding:12px 16px;font-size:12px;background:#fafbf7;line-height:1.6}
.web-terminal .terminal{transform:none!important;box-shadow:none!important;padding:0!important;border-radius:0!important;margin:0!important;font-family:monospace}
.web-terminal .xterm-viewport{scrollbar-width:thin;scrollbar-color:#607b6c #102723}
.web-terminal .xterm-screen{width:100%}
.web-terminal:focus-within{outline:2px solid #80a765;outline-offset:2px}
.terminal-task{padding:22px 26px;background:white;border:1px solid var(--line);border-radius:12px}
.terminal-task h2{margin-top:0}
@media(max-width:740px){.inline-lab{margin:18px -5px}.inline-lab .web-terminal{height:340px;padding:10px 7px}.inline-lab>.code-top{padding:12px;gap:4px}.inline-lab>.code-top span{width:100%}.inline-lab>.button-row{gap:10px;padding:10px 12px}.terminal-task{padding:18px}.topbar nav{gap:10px}.topbar nav a,.topbar nav button{font-size:11px}}