body{
  background-color: #eee;
  margin: 0;
  padding:0;
}
.container{
  width: 320px;
  background-color: #fff;
  margin: 1em auto;
  padding:1em;
  min-height: 450px;
  border-radius: 5px;
}
:root {
  --primary-color: #003b83;
}
label{
  cursor: pointer;
}

h1{
  font-size: 1.2em;
  color: var(--primary-color);
  text-align: center;
}
input[type="email"],input[type="password"]{
  width: 100%;
  box-sizing: border-box;
  margin: 0 auto 1em auto;
  padding: 0.3em;
  border-radius: 3px;
  background: darken(#f9f9f9, 10%);
  color: darken(#f9f9f9, 50%);
  border: 2px solid #ccc;
}
button{
  cursor: pointer;
  transition: 0.3s;
  width:7em;
  background: linear-gradient(to top, var(--primary-color), #3366bb);
  display: block;
  margin: 1em auto;
  padding: 0.7em;
  color: #fff;
  border-radius: 3px;
  text-decoration: none;  
  border:0px;  
}
button:hover {
  opacity: 0.5;
}
img{
  max-width: 60%;
}
.center{
  text-align: center;
}
.small{
  font-size: 0.9em;
}
.gray{
  color: #444;
}

/*警告表示*/
.alert {
  position: relative;
  padding: 1em;
  margin: 0.5em 0;
  border: 1px solid transparent;
  border-radius: 0.2em;
}
.alert-warning {
  color: #664d03; 
  background-color: #fff3cd;
  border-color: #ffecb5;
}
.alert-danger {
  color: #842029;
  background-color: #f8d7da;
  border-color: #f5c2c7;
}
.alert-success {
  color: #0f5132;
  background-color: #d1e7dd;
  border-color: #badbcc;
}
.alert-info {
  color: #055160;
  background-color: #cff4fc;
  border-color: #b6effb;
}