/* 共通レイアウトと基本スタイル */
html {
  scroll-behavior: smooth;
}

body {
  font-family: "Arial", sans-serif;
  line-height: 1.6;
  margin: 0;
  padding: 20px;
  background-color: #f9f9f9;
  color: #333;
  box-sizing: border-box;
  text-align: center;
}

h1, h2 {
  color: #2c3e50;
}

h1 {
  font-size: 2rem;
  border-bottom: 2px solid #3498db;
  padding-bottom: 0.5rem;
  margin-bottom: 1rem;
}

h2 {
  font-size: 1.5rem;
  margin-top: 2rem;
}

h3 {
  font-size: 1.2rem;
  margin-top: 1.5rem;
  color: #2c3e50;
}

p {
  margin: 0.5rem 0;
}

a {
  color: #3498db;
  text-decoration: none;
  transition: color 0.3s;
}

a:hover {
  color: #1e70bf;
  text-decoration: underline;
}

/* フォーム全体のスタイル */
.container {
  max-width: 400px;
  margin: 0 auto;
  background: #fff;
  padding: 2em;
  border-radius: 8px;
  box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
}

form {
  text-align: left;
}

label {
  display: block;
  margin-top: 10px;
  font-weight: bold;
}

input[type="text"],
input[type="password"],
button {
  width: 100%;
  padding: 10px;
  margin-top: 5px;
  margin-bottom: 15px;
  box-sizing: border-box;
  border: 1px solid #ccc;
  border-radius: 4px;
}

button {
  background-color: #3498db;
  color: #fff;
  border: none;
  cursor: pointer;
  transition: background 0.3s;
}

button:hover {
  background-color: #2980b9;
}

/* チャット画面用スタイル */
#chat {
  border: 1px solid #ccc;
  background-color: #fff;
  height: 300px;
  overflow-y: scroll;
  padding: 10px;
  margin: 1em auto;
  max-width: 600px;
  text-align: left;
}

#timeout-message {
  color: red;
  font-weight: bold;
  margin: 1em 0;
}

/* チャットフォーム */
#chatForm {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 10px;
  max-width: 600px;
  margin: auto;
}

#message {
  flex: 1;
  padding: 10px;
  font-size: 1rem;
}

#send {
  width: 100px;
  background-color: #3498db;
  color: #fff;
  border: none;
  border-radius: 4px;
  padding: 10px;
  font-weight: bold;
  cursor: pointer;
}

#send:hover {
  background-color: #2980b9;
}

        #popup {
            display: none;
            position: fixed;
            left: 50%;
            top: 50%;
            transform: translate(-50%, -50%);
            background: #fff;
            border: 1px solid #ccc;
            padding: 20px;
            z-index: 1000;
        }
        #popup-overlay {
            display: none;
            position: fixed;
            top: 0; left: 0;
            width: 100%; height: 100%;
            background: rgba(0, 0, 0, 0.5);
            z-index: 999;
        }

#roomList {
    list-style: none;
    padding: 0;
    margin: 0;
}


/* レスポンシブ対応 */
@media (max-width: 600px) {
  body {
    padding: 10px;
  }

  h1 {
    font-size: 1.5rem;
  }

  h2 {
    font-size: 1.2rem;
  }

  h3 {
    font-size: 1rem;
  }

  #chatForm {
    flex-direction: column;
  }

  #send {
    width: 100%;
  }
}