html, body {
  margin:0;
  padding:0;
  height: 100%;
  width: 100%;
}

body {
  background-color: #eee;
  font: 14px Roboto, 'Helvetica Neue',Helvetica, Arial, sans-serif;
}

header {
  background-color: dodgerblue;
  padding: 10px;
  font-size: 20px;
  color: white;
}

#container {
  max-width:100%;
  padding: 5px;
  margin: auto;
}

button {
  width: 150px;
  height: 40px;
  border-radius: 5px;
  outline: none;
  border: 0;
  text-transform: uppercase;
  background-color: deeppink;
  color: white;
  transition: box-shadow 0.3s, background-color 0.3s, color 0.3s;
  cursor: pointer;
  font-weight: bold;
}

button:hover {
  box-shadow: 0 2px 2px 0 rgba(0, 0, 0, 0.14), /*bottom*/ 0 1px 5px 0 rgba(0, 0, 0, 0.12), /*sides*/ 0 3px 1px -2px rgba(0, 0, 0, 0.2); /*top*/
  background-color: white;
  color: black;
}

input, textarea {
  padding: 5px;
  border-radius: 5px;
  border: 1px solid #ddd;
  height: 40px;
}

/**
a material design card.
 */
.card {
  margin: 16px;
  padding: 16px;
  border-radius: 5px;
  background-color: #fff;
  box-shadow: 0 2px 2px 0 rgba(0, 0, 0, 0.14), 0 1px 5px 0 rgba(0, 0, 0, 0.12), 0 3px 1px -2px rgba(0, 0, 0, 0.2);
  min-width: 250px;
  max-width:90%;
}

/**
declare which containers act as flex parents
 */
.flexParent {
  display: flex;
  flex-wrap: wrap;
}
/**
below .flexParent, flexChild will automatically adjust.
 */
.flexChild {
  flex: 1;
}

@media (max-width:400px) {
  .card {
    margin: 8px auto;
  }
}