body {
  margin: 0;
  font-family: Tahoma, Verdana, Arial, sans-serif;
  background-color: #333;
  color: #fff;
  text-align: center;
}

/* ヘッダーメニュー */
.top-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background-color: #222;
  padding: 10px 15px;
  flex-wrap: wrap; /* 狭い画面で折り返し */
}

.top-bar a {
  color: white;
  text-decoration: none;
  margin-right: 15px;
  font-weight: bold;
}

.top-bar a:hover {
  text-decoration: underline;
}

.left-links a:last-child {
  margin-right: 0;
}

/* 中央の大きなタイトル */
.welcome {
  font-size: 2.5em;
  font-weight: bold;
  margin: 60px 0 30px;
}

/* コンテンツ部分 */
.content {
  max-width: 800px;
  margin: auto;
  padding: 20px;
  line-height: 1.6;
}

a {
  color: #4da3ff;
}

/* DuckDuckGo 検索窓 */
.search-box {
  display: flex;
  justify-content: center;
  margin: 20px 0;
}

.search-box form {
  display: flex;
  width: 100%;
  max-width: 500px;
}

.search-box input[type="text"] {
  padding: 8px;
  font-size: 16px;
  border: none;
  border-radius: 4px 0 0 4px;
  flex: 1; /* 幅を可変に */
  min-width: 0;
}

.search-box input[type="submit"] {
  padding: 8px 15px;
  font-size: 16px;
  border: none;
  background-color: #4da3ff;
  color: white;
  border-radius: 0 4px 4px 0;
  cursor: pointer;
}

.search-box input[type="submit"]:hover {
  background-color: #1a73e8;
}

/* --- レスポンシブ対応 --- */
@media (max-width: 768px) {
  .welcome {
    font-size: 2em;
    margin: 40px 0 20px;
  }

  .top-bar {
    flex-direction: column;
    align-items: flex-start;
  }

  .top-bar .left-links,
  .top-bar .right-link {
    margin: 5px 0;
  }

  .search-box form {
    flex-direction: column;
  }

  .search-box input[type="text"],
  .search-box input[type="submit"] {
    border-radius: 4px;
    margin: 5px 0;
    width: 100%;
  }
}

@media (max-width: 480px) {
  .welcome {
    font-size: 1.6em;
  }

  body {
    font-size: 14px;
  }
}