@import url('https://fonts.googleapis.com/css?family=Open+Sans:300');

* {
 margin: 0;
 padding: 0;
 font-family: 'Open Sans',sans-serif;
 box-sizing: border-box;
}

html {
  background:url(/Papel-W.jpg) no-repeat center fixed;
  background-size: cover;
}

body {
 display: flex;
 flex-direction: column;
 min-height: 70vh;
}

.logo {
 margin: auto;
 width: 200px;
}

form {
 margin: auto;
 width: 50%;
 max-width: 500px;
 padding: 30px;
 border: 1px solid rgba(0,0,0,0.2);
}

h3 {
 text-align: center;
 margin-bottom: 20px;
 color: rgba(0,0,0,0.5);
}

input[type="text"] {
 display: block;
 padding: 10px;
 width: 100%;
 margin: 30px 0;
 font-size: 15px;
}

input[type="password"] {
 display: block;
 padding: 10px;
 width: 100%;
 margin: 30px 0;
 font-size: 15px;
}

input[type="submit"] {
 display: block;
 padding: 10px;
 width: 100%;
 margin: 30px 0;
 font-size: 15px;
}

input[type="submit"] {
 background: linear-gradient(#1ad1ff, #000099);
 border: 0;
 color: white;
 opacity: 0.8;
 cursor: pointer;
 border-radius: 20px;
 margin-bottom: 0;
}

input[type="submit"]:hover {
 opacity: 1;
}

input[type="submit"]:active {
 transform: scale(0.95);
}

@media (max-width:700px){
 form {
  width: 75%;
 }
}

@media (max-width:480px){
 form {
  width: 95%;
 }
}