:root{--bg: #f9fafb;--card-bg: #ffffff;--text: #1f2937;--muted: #6b7280;--border: #e5e7eb;--primary: #2563eb}body.dark-theme{--bg: #0f172a;--card-bg: #1e293b;--text: #e5e7eb;--muted: #9ca3af;--border: #334155;--primary: #60a5fa}html{scroll-behavior:smooth}body{margin:0;background:var(--bg);color:var(--text);font-family:Segoe UI,Roboto,Arial,sans-serif}section{scroll-margin-top:90px}