styles.css

body {
  background: #cecece;
  margin: 0;
  font: 62.5% Verdana, Arial, sans-serif;
  line-height: 1.6;
}

.wrapper {
  width: 600px;
  margin: 50px auto;
  padding: 20px;
  background: #fff;
  border: 1px solid #888;
  border-radius: 10px;
  font-size: 1.6em;
  text-align: center;
}
h1 {
  line-height: 1.2;
  margin-bottom: 30px;
  font-size: 1.8em;
  font-weight: 100;
}
.kana-container {
  height: 40px;
  margin-bottom: 10px;
}
form {
  margin: 0 0 10px;
}
.answer-input {
  background: #fff;
  border-radius: 5px;
  width: 200px;
  border: 1px solid #888;
  padding: 5px 10px;
  font: 1.2em Verdana, Arial, sans-serif;
  text-align: center;
}
.answer-response {
  height: 20px;
  margin-bottom: 20px;
}
.correct {
  color: green;
}
.wrong {
  color: red;
}
.wrong-list {
  list-style-type: none;
  margin: 10px auto;
  padding: 0;
  width: 250px;
}
.wrong-list li {
  padding: 2px 5px;
  line-height: 40px;
  border-bottom: 1px solid #cecece;
  overflow: hidden;
  text-align: center;
}
.wrong-list .kana {
  width: 80px;
  float: left;
}
.wrong-list .answer {
  float: left;
  width: 80px;
}
.wrong-list .guest {
  float: left;
  width: 80px;
}