#wrapper{width: 100%; margin-right: auto; margin-left: auto;}@media (min-width: 576px){#wrapper{max-width: 540px;}}@media (min-width: 768px){#wrapper{max-width: 720px;}}@media (min-width: 992px){#wrapper{max-width: 960px;}}@media (min-width: 1200px){#wrapper{max-width: 1140px;}}body{font-weight: bold; background-color: black; color: white;}h1{text-align: center; margin-top: 30px; margin-bottom:30px;}.main, .add{text-align: center;}.text{margin-top:10px; margin-bottom:5px; font-size: 1.8rem;}#vol1, #vol2{font-size: 35px; font-weight: bold; color: #008eff;}.result{text-align: center; font-size: 25px; margin-bottom: 20px;}.SNS{text-align: center; margin-top: 40px;}.SNS li{display:inline-block; margin: 0 5px;}.SNS li img{border-radius:50%;}#form-submit{margin-top: 20px; margin-bottom: 10px;}/*sns link*//* Style all font awesome icons */.fa{padding: 20px; font-size: 30px; width: 50px; text-decoration: none; border-radius: 50%;}/* Add a hover effect if you want */.fa:hover{opacity: 0.7;}/*holi_grail*/nav{flex-shrink:0;margin-top:0px;}.holi_grail{display:flex; justify-content: center;}