header { position: fixed; padding: 1.5rem 0; width: 100%; background: #fff; z-index: 9999;}
header .back { position: absolute; left: 1.5rem; top: 50%; transform: translateY(-50%); width: 1.2rem;}
header .back img { width: 100%;}
header p {font-size: 2rem; text-align: center; font-weight: 700;}