body,html{margin:0;padding:0;width:100%;height:100%;background:rgba(0,0,0,.5);display:flex;justify-content:center;align-items:center;font-family:Arial,sans-serif}.modal{background:#fff;padding:15px;border-radius:5px;box-shadow:0 0 10px rgba(0,0,0,.3);text-align:center;max-width:90%;width:300px;margin:10px}.modal p{font-size:14px;line-height:1.4;margin-bottom:15px}.mail-button,.return-button{display:block;width:100%;margin:10px 0;padding:12px;border-radius:5px;font-weight:700;text-decoration:none;font-size:14px;box-sizing:border-box}.mail-button{background:#007bff;color:#fff}.mail-button:hover{background:#0056b3}.return-button{background:#6c757d;color:#fff}.return-button:hover{background:#5a6268}@media (min-width:600px){.modal{padding:20px 30px;width:400px}.modal p{font-size:16px}.mail-button,.return-button{width:auto;padding:10px 20px;margin:10px auto}}