*{box-sizing:border-box}body{margin:0;font-family:var(--font-sans);background-color:var(--bg);background-image:radial-gradient(ellipse 80% 50% at 50% -20%,rgba(34,211,238,.08),transparent),radial-gradient(ellipse 60% 40% at 100% 0%,rgba(99,102,241,.05),transparent);color:var(--text);min-height:100vh}html.lecture-active{height:100%;overflow:hidden}