/* Shared tutorial identity: restrained aurora lighting, high-contrast reading surfaces. */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&family=Space+Grotesk:wght@500;600;700&family=JetBrains+Mono:wght@400;500&display=swap');
body{--ink:#eef2ff;--paper:#080d19;--muted:#b4bfd3;--line:rgba(255,255,255,.15);--blue:#a5b4fc;--mint:#67e8f9;--font:Inter,system-ui,sans-serif;--heading:"Space Grotesk",system-ui,sans-serif;background:radial-gradient(ellipse at 8% 0%,#4f46e51a,transparent 35%),radial-gradient(ellipse at 95% 5%,#06b6d413,transparent 30%),#080d19;color:var(--ink);font-family:var(--font)}
/* Glass navigation is shared with the homepage; dropdowns remain nearly opaque. */
.site-head{background:#0b1120e6;border-color:var(--line);backdrop-filter:blur(16px);-webkit-backdrop-filter:blur(16px)}.wordmark{font-family:var(--heading)}.nav-panel{background:#131d31f5;border-color:var(--line)}.nav-panel a{color:#e3eaff}.nav-panel a:hover{background:#818cf824;color:#a5f3fc}.nav-group>summary:hover,.nav-group[open]>summary,.global-nav>a:hover{background:#818cf81c;color:#c7d2fe}.global-nav>.nav-start{border-color:#818cf85c;color:#c7d2fe}a:focus-visible,button:focus-visible,summary:focus-visible{outline:3px solid #67e8f9;outline-offset:5px}
/* A compact chapter rail; no motion or glow behind long-form text. */
aside{border-color:var(--line)}aside p:first-child{color:#eef2ff}aside a{color:#b4bfd3}aside a:hover,aside a.current{background:#818cf819;color:#d0d7ff;border-left-color:#818cf8}h1,h2,h3{font-family:var(--heading)}h1{max-width:850px;color:#edf0ff}h2{color:#e6eaff}h3{color:#dce5ff}.eyebrow{color:#a5b4fc;font-family:"JetBrains Mono",monospace;font-size:13px}.lead{color:#b8c4d9}.meta span{background:#ffffff05;color:#c4cee1;border-color:var(--line)}.cloud-links a{color:#a5b4fc}
/* Reading panels keep the glass effect subtle and text contrast consistent. */
section{background:#111a2beb;border-color:var(--line);border-radius:16px;box-shadow:0 12px 36px #00000010}section p,section li{color:#d4dcee}section strong{color:#f1f4ff}.analogy{background:#818cf812;border-left-color:#818cf8;color:#dce2ff}.notice{background:#fbbf240c;border-left-color:#d9a43c;color:#e7dec4}.notice strong{color:#ffdf9e}.notice a{color:#b5dfff}.checkpoint{background:#34d3990b;border-color:#34d39940;color:#c4ecdf}.checkpoint strong{color:#a7f3d0}.flow div{background:#17243b;border:1px solid #818cf833;border-radius:10px}.flow small{color:#b8c7e4}
/* Terminal code panels: copy/download controls remain prominent and scroll is internal. */
code{background:#818cf816;color:#d1d9ff;font-family:"JetBrains Mono",ui-monospace,monospace}.snippet{border-color:#818cf843;border-radius:12px}.code-head{background:#1a2540;color:#d3dff4}.code-head a{color:#9cecf8}.code-head button{background:#818cf819;border-color:#818cf862;color:#eef2ff;border-radius:6px;min-height:36px}.code-head button:hover{background:#818cf833}pre{background:#080e1b;color:#d9e5ff;font-family:"JetBrains Mono",ui-monospace,monospace}pre code{color:inherit;background:none}.os button{color:#cdd7ed;background:#111a2b;border-color:var(--line)}.os button[aria-pressed=true]{background:#818cf826;color:#e5eaff;border-color:#818cf8}.os button:hover{border-color:#a5b4fc}
/* Tables and source links are readable without frosted text backgrounds. */
th{background:#1a2640;color:#dae4ff}td{color:#d0daed}th,td{border-color:var(--line)}tbody tr:nth-child(even){background:#ffffff05}.sources{color:#aebbd2}.sources a{color:#a5b4fc}footer{color:#aebbd2;border-color:var(--line)}footer a{color:#a5b4fc}
/* Mobile chapter disclosure uses the existing accessible toggle behavior. */
@media(max-width:850px){aside{background:#111a2bd9;border-color:var(--line);border-radius:12px}.chapter-toggle{background:#818cf819;color:#c7d2fe;border-color:#818cf85c}.global-nav{border-color:var(--line)}section{border-radius:12px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}}
/* Learning routes and infrastructure diagrams: readable cards on narrow screens. */
.diagram{display:grid;grid-template-columns:repeat(auto-fit,minmax(min(100%,210px),1fr));gap:14px;margin:24px 0}.diagram>div{padding:18px;background:#17243b;border:1px solid #818cf833;border-radius:12px}.diagram strong,.diagram small,.diagram a{display:block}.diagram small{font-size:14px;line-height:1.6;color:#b8c7e4;margin:6px 0 12px}.diagram a{padding:8px 0}