body { margin: 0; padding: 0; font-family: 'Arial', sans-serif; background: #000; color: #fff; }
.main-container { max-width: 750px; margin: 0 auto; position: relative; }
.image-box { position: relative; width: 100%; line-height: 0; }
.image-box img { width: 100%; height: auto; }

.floating-buttons {
    position: absolute; bottom: 20px; left: 50%;
    transform: translateX(-50%); display: flex; gap: 15px; width: 90%;
}
.action-btn {
    flex: 1; padding: 15px; border: none; border-radius: 10px;
    font-weight: bold; font-size: 16px; cursor: pointer; color: #fff;
    box-shadow: 0 4px 15px rgba(0,0,0,0.3); transition: 0.3s;
}
.btn-reg { background: linear-gradient(135deg, #ff9a9e 0%, #fecfef 99%, #fecfef 100%); color: #d63384; }
.btn-claim { background: linear-gradient(135deg, #667eea 0%, #764ba2 100%); }

/* Modal đơn giản */
.modal { display: none; position: fixed; z-index: 100; top: 0; left: 0; width: 100%; height: 100%; background: rgba(0,0,0,0.8); }
.modal-content { background: #fff; color: #333; margin: 20% auto; padding: 20px; width: 80%; max-width: 400px; border-radius: 15px; text-align: center; }
input { width: 90%; padding: 12px; margin: 15px 0; border: 1px solid #ddd; border-radius: 8px; }