:root{--bg:#f8f7fa;--panel:#fff;--ink:#28232e;--muted:#6b6474;--line:#e5e0eb;--accent:#714b89;--soft:#f0eaf5;--terminal:#29262e;--terminal-ink:#eeeaf2;--good:#277451;--bad:#ad433f;color-scheme:light;font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif}
:root[data-theme=dark]{--bg:#26242b;--panel:#322f38;--ink:#eeeaf1;--muted:#c0b9c9;--line:#504956;--accent:#dec3ed;--soft:#403947;--good:#a5d9bd;--bad:#f1aaa2;color-scheme:dark}
:root[data-theme=purple]{--bg:#f6f1fa;--panel:#fff;--soft:#ece1f4;--accent:#70458f}
*{box-sizing:border-box}body{margin:0;color:var(--ink);background:var(--bg);font-size:15px;line-height:1.65}a{color:var(--accent);text-underline-offset:4px}button,input,select,textarea{font:inherit}button,a,select{touch-action:manipulation}button{cursor:pointer}button:disabled{cursor:default;opacity:.55}button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible,textarea:focus-visible,summary:focus-visible{outline:3px solid var(--accent);outline-offset:3px}button{border:0;border-radius:9px;padding:9px 15px;font-weight:650;background:var(--accent);color:var(--panel)}:root[data-theme=dark] button{color:#29232f}button.secondary{background:var(--soft);color:var(--accent);border:1px solid var(--line)}.icon-button{background:transparent;color:var(--ink);padding:6px 10px;font-size:22px}.skip{position:absolute;left:10px;top:-80px;z-index:99;background:var(--panel);padding:10px}.skip:focus{top:10px}.site-header{position:relative;display:flex;align-items:center;justify-content:space-between;gap:20px;padding:20px 5vw;border-bottom:1px solid var(--line);background:var(--panel)}.brand{display:flex;align-items:center;gap:13px;color:var(--ink);text-decoration:none;line-height:1.25;font-size:15px}.brand strong{display:block;font-size:22px;letter-spacing:-.6px}.brand-mark{width:43px;height:43px;border-radius:13px;background:var(--soft);color:var(--accent);font-weight:850;font-size:24px;text-align:center;position:relative;line-height:43px}.brand-mark span{font-size:15px;position:absolute;right:2px;top:-10px}.site-header nav{display:flex;align-items:center;gap:24px;font-size:13px}.site-header nav a{text-decoration:none}.account-menu{position:absolute;right:5vw;top:85px;width:300px;max-width:90vw;background:var(--panel);border:1px solid var(--line);border-radius:14px;padding:20px;box-shadow:0 15px 50px #24112b22;z-index:10}.account-menu label{display:block;font-size:12px;margin:15px 0 5px}.account-menu select{width:100%;padding:8px;border:1px solid var(--line);border-radius:8px;background:var(--bg);color:var(--ink)}.account-menu p{font-size:12px;color:var(--muted)}main{max-width:1500px;margin:auto;padding:48px 5vw 70px;min-height:75vh}.eyebrow{font-size:11px;letter-spacing:1.9px;text-transform:uppercase;font-weight:750;color:var(--accent)}h1{font-size:clamp(32px,4.5vw,54px);line-height:1.13;letter-spacing:-1.8px;margin:13px 0 20px}h2{font-size:25px;letter-spacing:-.6px;line-height:1.25}h3{line-height:1.35}p{margin:10px 0 17px}.intro{max-width:680px;font-size:17px;color:var(--muted)}.home-hero{padding:10px 0 30px}.hero-meta{display:flex;gap:20px;font-size:12px;color:var(--muted);margin-top:24px}.course-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:20px}.course-card,.panel,.unit-card{background:var(--panel);border:1px solid var(--line);border-radius:18px;padding:26px}.course-card{position:relative;display:flex;flex-direction:column;min-height:250px;overflow:hidden}.course-card .number{font-size:12px;color:var(--muted)}.course-card h2{margin:20px 0 8px}.course-card p{font-size:14px;color:var(--muted);max-width:460px}.course-card>a{margin-top:auto;align-self:flex-start;font-weight:700;font-size:14px;text-decoration:none}.course-card .badge{position:absolute;right:24px;top:24px}.badge{display:inline-block;background:var(--soft);color:var(--accent);border-radius:30px;padding:3px 11px;font-size:11px;font-weight:650}.badge.neutral{color:var(--muted);background:var(--bg)}.note{font-size:13px;background:var(--soft);padding:14px 18px;border-radius:10px;color:var(--muted);border-left:3px solid var(--accent)}.breadcrumbs{font-size:12px;color:var(--muted);margin-bottom:25px}.unit-list{display:grid;gap:20px;margin-top:30px}.unit-card h2{margin:9px 0}.unit-card p{color:var(--muted)}.unit-links{display:flex;gap:15px;flex-wrap:wrap;margin-top:20px}.unit-links a{font-size:13px;font-weight:650}.course-layout{display:grid;grid-template-columns:245px minmax(0,1fr);gap:35px;position:relative}.course-nav{align-self:start;border-right:1px solid var(--line);padding:0 18px 25px 0;position:relative}.menu-caret{position:absolute;top:0;right:0;background:transparent;color:var(--muted);font-size:24px;padding:0 5px;line-height:1.3}.course-nav h2{font-size:16px;margin:0 20px 20px 0}.course-nav h3{font-size:11px;color:var(--muted);text-transform:uppercase;letter-spacing:1px;margin:20px 0 8px}.course-nav a{display:block;font-size:12px;padding:8px 10px;margin:3px 0;border-radius:8px;text-decoration:none;color:var(--muted)}.course-nav a[aria-current=page]{background:var(--soft);color:var(--accent);font-weight:700}.course-nav a.quiz-link{border-top:1px solid var(--line);border-radius:0;margin-top:7px}.course-layout.collapsed{grid-template-columns:25px minmax(0,1fr);gap:14px}.course-layout.collapsed .course-nav{padding:0;border:0}.course-layout.collapsed .course-nav>*:not(.menu-caret){display:none}.lesson-heading h1{font-size:clamp(28px,3vw,39px);letter-spacing:-1px}.lesson-heading .badge{margin:0 6px 7px 0}.lesson-grid{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1.05fr);gap:24px;margin-top:25px;align-items:start}.lesson-copy h2{font-size:19px;margin-top:25px}.lesson-copy h2:first-child{margin-top:0}pre,code,textarea{font-family:ui-monospace,SFMono-Regular,Consolas,monospace}code{font-size:.92em;background:var(--soft);padding:2px 4px;border-radius:4px}pre{white-space:pre-wrap;overflow-wrap:anywhere;background:var(--terminal);color:var(--terminal-ink);padding:18px;border-radius:10px;font-size:12px;line-height:1.65;overflow:auto}.workspace{padding:0;overflow:hidden}.workspace-head{display:flex;align-items:center;justify-content:space-between;border-bottom:1px solid var(--line);padding:12px 16px;font-size:12px}.workspace-head strong{font-size:13px}.workspace textarea{width:100%;display:block;height:360px;min-height:180px;resize:vertical;border:0;border-radius:0;background:var(--terminal);color:var(--terminal-ink);padding:17px;font-size:12px;line-height:1.65;tab-size:4}.toolbar{display:flex;gap:8px;flex-wrap:wrap;padding:12px 16px}.toolbar button,.toolbar a{font-size:12px}.toolbar a{align-self:center}.workspace-body{padding:0 18px 18px}.workspace-body p{font-size:12px;color:var(--muted)}.workspace.is-expanded{position:fixed;inset:15px;z-index:30;overflow:auto;box-shadow:0 0 0 100vmax #20162988}.workspace.is-expanded textarea{height:55vh}.workspace.is-expanded .workspace-head{position:sticky;top:0;background:var(--panel);z-index:2}.compact-button{background:var(--soft);color:var(--accent);font-size:11px;padding:5px 9px}.examples{width:100%;border-collapse:collapse;font-size:12px}.examples th,.examples td{text-align:left;border-bottom:1px solid var(--line);padding:9px 4px;vertical-align:top;overflow-wrap:anywhere}.examples code{white-space:normal}.unity-task{margin-top:24px}.unity-task label{display:flex;gap:10px;align-items:flex-start;font-size:14px;margin:14px 0}.unity-task input{margin-top:7px;accent-color:var(--accent)}.unity-task textarea{width:100%;min-height:85px;padding:12px;border:1px solid var(--line);border-radius:8px;color:var(--ink);background:var(--bg)}.lesson-bottom{display:flex;justify-content:space-between;gap:12px;margin-top:26px;font-size:13px}.quiz-intro{max-width:700px}.question{padding:23px 0;border-bottom:1px solid var(--line)}fieldset{border:0;margin:0;padding:0}legend{font-weight:650;padding:0;margin:0 0 13px}.choice{display:flex;align-items:flex-start;gap:10px;padding:10px 13px;border:1px solid var(--line);border-radius:9px;margin:7px 0;font-size:14px;cursor:pointer}.choice:has(input:checked){background:var(--soft);border-color:var(--accent)}.choice input{margin-top:6px;accent-color:var(--accent)}.quiz-feedback{font-size:13px;padding:12px;background:var(--soft);border-radius:8px;margin:10px 0}.quiz-feedback.correct{border-left:3px solid var(--good)}.quiz-feedback.incorrect{border-left:3px solid var(--bad)}.quiz-actions{display:flex;gap:15px;align-items:center;flex-wrap:wrap;margin-top:25px}.progress-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:15px;margin:25px 0}.stat{background:var(--panel);border:1px solid var(--line);padding:24px;border-radius:14px}.stat strong{font-size:30px;display:block}.stat span{font-size:12px;color:var(--muted)}.progress-row{display:flex;justify-content:space-between;gap:20px;padding:17px 0;border-bottom:1px solid var(--line);font-size:14px}.loading{padding:80px 0;text-align:center;color:var(--muted)}details{margin:12px 0;font-size:13px}summary{cursor:pointer;font-weight:650}.sr-only{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap}footer{max-width:1500px;margin:auto;border-top:1px solid var(--line);padding:24px 5vw;display:flex;justify-content:space-between;gap:15px;color:var(--muted);font-size:12px}[hidden]{display:none!important}
@media(max-width:1150px){.lesson-grid{grid-template-columns:1fr}.course-layout{gap:22px;grid-template-columns:210px minmax(0,1fr)}}@media(max-width:750px){main{padding:30px 5vw 50px}.site-header{padding:16px 5vw;flex-wrap:wrap}.site-header nav{gap:20px}.course-grid{grid-template-columns:1fr}.course-layout{grid-template-columns:1fr}.course-nav{border-right:0;border-bottom:1px solid var(--line);padding-bottom:18px}.course-layout.collapsed{grid-template-columns:1fr}.course-layout.collapsed .course-nav{min-height:28px}.course-layout.collapsed .menu-caret{left:0;right:auto}.course-nav a{padding:6px 10px}.progress-grid{grid-template-columns:1fr}.lesson-grid{grid-template-columns:1fr}.course-card{min-height:230px}.hero-meta{flex-wrap:wrap}.brand strong{font-size:20px}footer{flex-direction:column}}

:root[data-theme=dark] button.secondary,:root[data-theme=dark] .compact-button,:root[data-theme=dark] .icon-button,:root[data-theme=dark] .menu-caret{color:var(--accent)}

.csharp-terminal{background:var(--terminal);color:var(--terminal-ink);border-top:1px solid #54495e}
.terminal-heading{display:flex;justify-content:space-between;gap:10px;flex-wrap:wrap;padding:10px 16px;background:#35303b;font-size:11px;color:#eee6f3}
.csharp-terminal #csharp-output{min-height:140px;max-height:500px;height:170px;resize:vertical;overflow:auto;margin:0;border-radius:0;padding:16px;font-size:13px;line-height:1.6;white-space:pre-wrap;overflow-wrap:anywhere}
.workspace-body .check-feedback{background:transparent;color:var(--ink);padding:0;white-space:pre-wrap;font:12px/1.7 ui-monospace,SFMono-Regular,Consolas,monospace}
.workspace-body h3{font-size:13px}
.workspace[aria-busy=true] #stop-code{opacity:1}

.debug-workspace .workspace-body label{display:block;font-weight:650;margin:16px 0 7px}
.debug-workspace .workspace-body textarea{min-height:88px;height:auto;max-height:250px;resize:vertical;border:1px solid var(--line);border-radius:8px;background:var(--bg);color:var(--ink);font:inherit;padding:12px}
.debug-workspace select{max-width:100%;padding:9px 12px;border:1px solid var(--line);border-radius:8px;background:var(--bg);color:var(--ink)}
.debug-workspace #debug-output{min-height:140px;height:170px;max-height:500px;resize:vertical;overflow:auto;margin:0;padding:16px;border-radius:0;font-size:13px;line-height:1.6;white-space:pre-wrap;overflow-wrap:anywhere}
.debug-workspace #debug-hints li{padding:5px 0}