header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 2px solid black;
  padding: 10px 20px;
  margin: 0;
}

.logo-area {
  display: flex;
  align-items: center;
  text-decoration: none;
}

.logo-area img {
  height: 50px;
}

.site-name {
  font-size: 24px;
  font-weight: bold;
  margin-left: 10px;
  color: black;
  text-decoration: none;
}

.paw {
  font-size: 24px;
  margin-left: 5px;
}

nav a {
  margin-left: 20px;
  text-decoration: none;
  color: black;
  font-weight: bold;
}

body {
  margin: 0;
  font-family: sans-serif;
  text-align: center;
}

input[type="number"] {
  font-size: 1.2em;
  padding: 5px;
  width: 250px;
}

button {
  font-size: 1.2em;
  font-weight: bold;
  padding: 8px 16px;
  margin-top: 10px;
  background-color: white;
  border: solid 2px black;
  border-radius: 15px;
}

#primeTable {
  /* position: fixed; */
  margin-top: 20px;
  max-height: 500px;
  overflow-y: auto;
  text-align: left;
  margin-left: auto;
  margin-right: auto;
  width: 95%;
  border: 1px solid #ccc;
  padding: 10px;  
  line-height: 1.6;
  /* 行間を広くする */
  word-break: break-word;
  /* 単語単位で折り返す */
  font-family: monospace;
  /* 等幅フォントで視認性向上 */
  background: #fafafa;
  font-size: 16px; font-weight: bold;  
  /* margin-bottom: 200px; */
}

.prime-section-title {
  font-weight: bold;
  font-size: 16px;  
  margin-top: 10px;
}

.prime-numbers {
  font-size: 16px;
  white-space: normal;
  /* 折り返し許可 */
  word-wrap: break-word;
  margin-bottom: 20px;
}

button:hover {
  transform: scale(1.1);
}

#modeButtons button {
    margin: 5px;
    padding: 8px 12px;
    font-size: 1em;
}
input[type="number"] {
    margin: 5px;
}

.fraction-line {
    width: 100%;
    height: 2px;
    background-color: black;
}

.result {
  font-size: 24px;
  font-weight: bold;
  margin-top: 30px;  
  word-break: break-all;
}