@font-face{font-family:Google Sans Flex;src:url(/fonts/GoogleSansFlex.ttf) format("truetype");font-weight:1 1000;font-style:normal;font-display:swap}:root{--bg: #ffffff;--text: #2c3e50;--heading: #1a1a1a;--border: #e0e0e0;--link: #2563eb;--transition: .3s cubic-bezier(.4, 0, .2, 1)}[data-theme=dark]{--bg: #0f172a;--text: #cbd5e1;--heading: #f8fafc;--border: #1e293b;--link: #60a5fa}body{font-family:Google Sans Flex,system-ui,sans-serif;background-color:var(--bg);color:var(--text);max-width:800px;margin:0 auto;padding:40px 24px;line-height:1.75;transition:background-color var(--transition),color var(--transition)}.header-top{display:flex;justify-content:space-between;align-items:center;margin-bottom:2rem}h1{font-size:2.25rem;font-weight:800;letter-spacing:-.025em;color:var(--heading);margin:0}#theme-toggle{background:none;border:1px solid var(--border);border-radius:8px;padding:8px;cursor:pointer;display:flex;align-items:center;transition:background-color .2s}#theme-toggle:hover{background-color:var(--border)}#theme-icon{width:20px;height:20px;filter:brightness(0) saturate(100%)}[data-theme=dark] #theme-icon{filter:brightness(0) saturate(100%) invert(.9)}section{margin-bottom:3rem;opacity:0;transform:translateY(20px);transition:opacity .8s ease,transform .8s ease}section.visible{opacity:1;transform:translateY(0)}a{color:var(--link);text-decoration:none;font-weight:500;transition:opacity .2s}a:hover{opacity:.8}.notebook-link:after{content:"";display:inline-block;width:1.1em;height:1.1em;margin-left:4px;vertical-align:middle;-webkit-mask:url(/icons/notebook.svg) no-repeat center / contain;mask:url(/icons/notebook.svg) no-repeat center / contain;background-color:var(--link)}footer{margin-top:80px;padding-top:20px;border-top:1px solid var(--border);font-size:.875rem;text-align:center;opacity:.7}