body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f4f4f4;
    color: #333;
    min-height: 100vh; /* 最低でも画面の高さいっぱいにする */
    display: flex;
    flex-direction: column;
}

header {
    background:linear-gradient(#007BFF,#4072cf);
    color: white;
    padding: 10px 0;
    text-align: center;
}

header h1 {
    margin: 0;
    font-size: 2.5em;
}

main {
    flex: 1; /* メインコンテンツが残りの高さを占める */
    padding: 20px;
}

main h2 {
    margin: 0;
    text-align: center;
    font-size: 1.8em;
}

.emphasis_design {
    position: relative;
    color: #4d6cc1;
    z-index: 1;
  }
  .emphasis_design::before,.emphasis_design::after {
    width: 100%;
    color: #fff;
    content: attr(data-text);
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    -webkit-transform: translate(-50%, -50%);
    -ms-transform: translate(-50%, -50%);
  }
  .emphasis_design::before {
    -webkit-text-stroke: 3px #fff;
    z-index: -1;
  }
  .emphasis_design::after {
    -webkit-text-stroke: 2px #454545;
    z-index: -2;
  }

main h3 {
    margin: 20px;
    text-align: center;
    box-sizing: border-box;
    box-shadow: #454545;
    border-radius: 20px;
    padding: 10px;
    width: 200px;
    color: white;
}

.teacher-content-header {
    display: flex; 
    align-items: center; 
    justify-content: flex-start; 
}

.teacher-content-title {
    background-color: #4662dd;

}

.title-logo {
    margin-left: 10px;
    height: 100px;
}

.student-content-title {
    background-color: #ff6600;

}

.content-list {
    list-style-type: none;
    padding: 0;
    display: flex;
    flex-wrap: wrap;
    justify-content: space-around;
}

.content-list li {
    width: 250px; /* 固定サイズ */
    height: 320px; /* 固定サイズ＋タイトルと紹介文の高さ */
    margin: 35px;
    overflow: hidden;
    position: relative;
    border: 2px solid #b9b8b8;
    background-color: #ffff;
    box-sizing: border-box;
}

.content-list li a {
    display: block;
    width: 100%;
    height: 100%;
    position: relative;
    overflow: hidden;
    text-decoration: none;
    color: inherit;
}

.content-list li .thumbnail {
    width: 100%;
    height: 200px; /* サムネイルの高さ */
    margin-top: 45px;
    overflow: hidden;
}

.content-list li img {
    width: 100%;
    height: 100%;
    transition: transform 0.3s ease; /* ホバー時のアニメーション */
}

.content-list li:hover img {
    transform: scale(1.1); /* ホバー時に拡大 */
}

.content-list li span {
    display: block;
    width: 100%;
    background-color: #1ad138;
    color: white;
    padding: 8px;
    text-align: center;
    box-sizing: border-box;
    position: absolute;
    top: 0;
    left: 0;
    z-index: 1;
    font-weight: bold;
    font-size: large;
}

.content-list li span:hover {
    background-color: #0056b3;
}

.content-list li p {
    margin: 0;
    padding: 10px;
    font-size: 1em;
}

footer {
    background:linear-gradient(#007BFF,#4072cf);
    color: white;
    text-align: center;
    padding: 10px 0;
    width: 100%;
}

@media (max-width: 600px) {
    header h1 {
        font-size: 1.5em;
    }

    main {
        padding: 10px;
    }

    main h2 {
        font-size: 1.5em;
    }

    main h3 {
        margin-left: auto;
        margin-right: auto;
    }

    .content-list {
        flex-direction: column;
        align-items: center;
    }

    .content-list li {
        width: 100%;
        margin: 5px 0;
    }

    .content-list li img {
        height: auto;
    }
}