body { margin-top: 50px; }

.principal { background: #f3f7fa; padding: 10px 50px 40px; }
.principal h1 { text-align: center; font-weight: 700; margin-bottom: 40px; }
.principal p { text-align: left; font-size:18px; font-weight: 300; }

.error { background: #f3f7fa; padding: 10px 50px 40px; text-align: center; }
.error h1 { font-weight: 700; margin-bottom: 40px; }
.error p { font-size:18px; font-weight: 300; }

.btn-align { text-align: center; margin-top:25px; }
.btn-back { padding: 10px 50px; border-radius: 0px; font-weight: 700; }