:root{--bg-primary: #ffffff;--bg-secondary: #f8f9fa;--text-primary: #1a1a1a;--text-secondary: #4a4a4a;--accent-color: #007bff;--accent-hover: #0056b3;--border-color: #e0e0e0;--shadow-sm: 0 1px 2px rgba(0, 0, 0, .05);--shadow-md: 0 4px 6px rgba(0, 0, 0, .1);--font-sans: "Inter", system-ui, -apple-system, sans-serif}[data-theme=dark]{--bg-primary: #121212;--bg-secondary: #1e1e1e;--text-primary: #e0e0e0;--text-secondary: #a0a0a0;--accent-color: #3b82f6;--accent-hover: #2563eb;--border-color: #333333;--shadow-sm: 0 1px 2px rgba(255, 255, 255, .05);--shadow-md: 0 4px 6px rgba(0, 0, 0, .3)}*{box-sizing:border-box;margin:0;padding:0}html{scroll-behavior:smooth}body{font-family:var(--font-sans);background-color:var(--bg-primary);color:var(--text-primary);line-height:1.6;transition:background-color .3s ease,color .3s ease}a{text-decoration:none;color:inherit}button{cursor:pointer;border:none;background:none;font-family:inherit}ul{list-style:none}.container{max-width:1200px;margin:0 auto;padding:0 1.5rem}.section{padding:5rem 0}