:root{--bg: #0f1115;--surface: #171923;--text: #e5e7eb;--muted: #9aa0a6;--accent: #4f46e5}*{box-sizing:border-box}html,body,#root{height:100%}body{margin:0;font-family:ui-sans-serif,system-ui,-apple-system,Segoe UI,Roboto,Helvetica,Arial,"Apple Color Emoji","Segoe UI Emoji";background:var(--bg);color:var(--text)}.app-shell{min-height:100%;display:flex;flex-direction:column}.app-header{position:sticky;top:0;background:var(--surface);border-bottom:1px solid #23263a;padding:10px 16px}.nav{display:flex;align-items:center;gap:12px}.nav a{color:var(--text);text-decoration:none;padding:6px 10px;border-radius:8px}.nav a:hover{background:#23263a}.nav-spacer{flex:1}.app-main{padding:24px 16px;max-width:1100px;margin:0 auto}h1{margin:0 0 12px;font-size:24px}