*{
    margin: 0;
    padding: 0;
}

.cnt{
    background-color: white;
    max-width: 900px;
    opacity: 0.8;
    padding: 10px;
    margin-top: 7%;
    border-radius: 20px;
}

/* Layout: */

.col-main {
  flex: 1;  
}  

.col-complementary {
  flex: 1;  
}

/* Responsive: */

@media only screen and (min-width: 640px) {
  .layout {
    display: flex;
  }
}

.container {
  max-width: 60em;
  margin-right: auto;
  margin-left: auto;
}

.col {
  padding: 1em;
  margin: 0 2px 2px 0;
  background: #b3e888;
}

::placeholder { /* Chrome, Firefox, Opera, Safari 10.1+ */
  color: white;
  font-weight: bold;
  opacity: 1; /* Firefox */
}

.btn{
    width: 200px;
    font-size: 20px;
    padding: 10px;
    border: none;
    border-radius: 20px;
    font-weight: bold;
    background: black;
    color: white;
}

.frm input,select {
  width: 70%;
  font-size: 17px;
  font-weight: bold;
  margin: 5px 0 22px 0;
  padding: 10px;
  border: 5px solid;
  border-color: #9EFF33;
  background: #000000cc;
  color: white;
  -moz-box-sizing: border-box;
  -webkit-box-sizing: border-box;
  box-sizing: border-box;
}

.frm input:focus, select:focus {
  background-color: #000000cc;
}