body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    text-align: center;
    background-color: #f4f4f4;
}

/* ヘッダー */
header {
    background: #333;
    color: white;
    padding: 5px 0; /* 高さを減らす */
}

/* ナビゲーションメニュー */
nav {
    background: #444;
    padding: 5px 0; /* 高さを減らす */
}

nav ul {
    list-style: none;
    padding: 0;
    display: flex;
    justify-content: center;
    gap: 15px;
    flex-wrap: nowrap; /* 折り返し防止 */
    overflow-x: auto; /* 画面が狭い場合は横スクロール */
    white-space: nowrap; /* 開業防止 */
}

nav ul li {
    display: inline;
}

nav ul li a {
    color: white;
    text-decoration: none;
    font-size: 18px;
    padding: 5px 10px; /* 高さを減らす */
    display: block;
}

/* メインタイトル */
h1 {
    margin-top: 20px;
    font-size: 24px;
}

/* カレンダー画像 */
.calendar-container {
    display: flex;
    justify-content: center;
    margin-top: 20px;
}

.calendar-container img {
    max-width: 100%;
    height: auto;
    max-height: 80vh; /* デバイスの高さに収める */
    cursor: pointer;
    border-radius: 8px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
}

/* フルスクリーン表示 */
#fullscreen-container {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.8);
    justify-content: center;
    align-items: center;
    z-index: 1000;
}

#fullscreen-img {
    max-width: 90%;
    max-height: 90%;
}

#close-btn {
    position: absolute;
    top: 20px;
    right: 30px;
    font-size: 30px;
    color: white;
    cursor: pointer;
}

/* カレンダー画像のグリッド表示 */
.calendar-grid {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    justify-content: center;
    padding: 20px;
}

.calendar-thumbnail {
    width: 150px;
    height: auto;
    cursor: pointer;
    transition: transform 0.2s ease-in-out;
}

.calendar-thumbnail:hover {
    transform: scale(1.1);
}

/* スマホ対応 */
@media (max-width: 600px) {
    nav ul {
        flex-wrap: nowrap;
        gap: 10px;
        overflow-x: auto;
        white-space: nowrap;
        padding: 5px;
    }

    nav ul li a {
        font-size: 14px;
        padding: 5px 8px;
    }

    .calendar-thumbnail {
        width: 120px;
    }

    #close-btn {
        font-size: 25px;
        right: 20px;
    }
}

#message-form {
    max-width: 600px;
    margin: 0 auto;
    padding: 20px;
    background: #f9f9f9;
    border-radius: 8px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
}

textarea {
    width: 100%;
    height: 120px;
    resize: none;
    padding: 10px;
}

.message-container {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    justify-content: center;
}

.message-box {
    width: 250px;
    padding: 10px;
    border-radius: 8px;
    background: #fff;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    word-break: break-word;
    cursor: pointer;
    transition: transform 0.2s, box-shadow 0.2s;
}

.message-box:hover {
    transform: scale(1.02);
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.2);
}

.message-content {
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    max-width: 200px;
}

.fullscreen-container {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.8);
    justify-content: center;
    align-items: center;
    z-index: 1000;
}

.fullscreen-content {
    background-color: white;
    padding: 20px;
    border-radius: 5px;
    max-width: 80%;
    max-height: 80%;
    overflow-y: auto;
    text-align: center;
}

.close-fullscreen {
    position: absolute;
    top: 20px;
    right: 20px;
    font-size: 30px;
    color: white;
    cursor: pointer;
}

.login-container {
    background-color: white;
    padding: 20px;
    border-radius: 5px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    display: inline-block;
    text-align: left;
}

.login-container form {
    display: flex;
    flex-direction: column;
}

.login-container label {
    margin-bottom: 5px;
}

.login-container input {
    margin-bottom: 10px;
    padding: 8px;
    border: 1px solid #ccc;
    border-radius: 3px;
}

.login-container button {
    padding: 10px;
    background-color: #333;
    color: white;
    border: none;
    border-radius: 3px;
    cursor: pointer;
}

.login-container button:hover {
    background-color: #555;
}