:root{--primary-color: #4CAF50;--text-color: #333;--bg-color: #f5f5f5;--ad-color: #ff0000;--white: #ffffff;--border-color: #e0e0e0}*{box-sizing:border-box;margin:0;padding:0}body{font-family:Segoe UI,Tahoma,Geneva,Verdana,sans-serif;background-color:var(--bg-color);color:var(--text-color);line-height:1.6}.container{max-width:1200px;margin:0 auto;padding:0 15px}.flex{display:flex}.flex-col{flex-direction:column}.items-center{align-items:center}.justify-center{justify-content:center}.justify-between{justify-content:space-between}.w-full{width:100%}.text-center{text-align:center}.font-bold{font-weight:700}