body { font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; background: #f0f2f5; margin: 0; padding: 20px; text-align: center; }
.container { max-width: 700px; margin: 0 auto; background: #fff; padding: 30px; border-radius: 15px; box-shadow: 0 4px 15px rgba(0,0,0,0.1); }
.ad-space { background: #eee; margin: 20px auto; display: flex; align-items: center; justify-content: center; border: 1px dashed #ccc; color: #999; }
.ad-leader { width: 100%; height: 90px; max-width: 728px; }
.ad-rect { width: 300px; height: 250px; }
.progress-bar { width: 100%; background: #e0e0e0; height: 10px; border-radius: 5px; margin: 20px 0; overflow: hidden; }
.progress-fill { height: 100%; background: #000; transition: width 0.5s; }
h1 { font-size: 22px; color: #333; }
.step-icon { font-size: 40px; margin-bottom: 10px; display: block; }
.loader { border: 4px solid #f3f3f3; border-top: 4px solid #333; border-radius: 50%; width: 30px; height: 30px; animation: spin 1s linear infinite; margin: 0 auto; }
@keyframes spin { 0% { transform: rotate(0deg); } 100% { transform: rotate(360deg); } }