:root{--text:#1b1b1b;--muted:#666;--link:#004aad;--bg:#ffffff;--border:#e5e5e5;--heading-font:"Georgia", serif;--body-font:"Segoe UI", sans-serif}body{margin:0;padding:0;background-color:var(--bg);color:var(--text);font-family:var(--body-font);line-height:1.65}header{padding:3.5rem 1.5rem 2.5rem;text-align:center;border-bottom:1px solid var(--border)}header h1{font-size:2.2rem;margin:0;letter-spacing:.5px;font-family:var(--heading-font);font-weight:400}header p{font-size:1.05rem;color:var(--muted);margin-top:.5rem}main{max-width:820px;margin:3rem auto;padding:0 1.5rem}section h2{font-size:1.4rem;margin-bottom:1rem;padding-bottom:.4rem;font-family:var(--heading-font);font-weight:400;border-bottom:1px solid var(--border)}ul.notebook-list{list-style:none;padding:0;margin:0}ul.notebook-list li{margin:0 0 1.4rem;padding-bottom:1.4rem;border-bottom:1px solid var(--border)}ul.notebook-list li:last-child{border-bottom:none}ul.notebook-list a{text-decoration:none;color:var(--link);font-weight:500;font-size:1.05rem}ul.notebook-list a:hover{text-decoration:underline}ul.notebook-list p{margin:.4rem 0 0;color:var(--muted);font-size:.95rem}details{border:1px solid var(--border);border-radius:6px;margin-bottom:1.6rem;padding:.8rem 1rem;background-color:var(--bg);transition:background-color 0.2s ease}details:hover{background-color:rgb(0 0 0 / .02)}details summary{font-size:1.05rem;font-weight:500;cursor:pointer;color:var(--link);list-style:none;outline:none;display:flex;align-items:center;gap:.4rem;padding:.3rem 0}details summary::marker{display:none}details summary::before{content:"▸";transition:transform 0.2s ease;display:inline-block;font-size:1rem;color:var(--muted)}details[open] summary::before{transform:rotate(90deg)}details[open] summary{color:var(--link)}footer{padding:3rem 1.5rem 2rem;border-top:1px solid var(--border);font-size:.9rem;color:var(--muted);text-align:center}@media (prefers-color-scheme:dark){:root{--text:#ddd;--muted:#aaa;--link:#89b4ff;--bg:#111;--border:#2a2a2a}details:hover{background-color:rgb(255 255 255 / .05)}}