* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f8f9fa;
}

header {
    background-color: #2c3e50;
    color: white;
    text-align: center;
    padding: 1rem 0;
}
/* 上部に表示する開発中バナー */
.dev-banner {
    background-color: #ff9800;
    color: white;
    text-align: center;
    padding: 8px 0;
    font-weight: bold;
    position: sticky;
    top: 0;
    z-index: 1000;
    font-size: 14px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}
.container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem 0;
}

.video-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.5rem;
}

.video-item {
    background: white;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s;
}

.video-item:hover {
    transform: translateY(-5px);
}

.thumbnail-container {
    position: relative;
    width: 100%;
    padding-top: 56.25%; /* 16:9 アスペクト比 */
    overflow: hidden;
}

.thumbnail {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.play-icon {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 60px;
    height: 60px;
    background-color: rgba(255, 0, 0, 0.7);
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    opacity: 0.8;
}

.play-icon:before {
    content: '';
    width: 0;
    height: 0;
    border-style: solid;
    border-width: 10px 0 10px 20px;
    border-color: transparent transparent transparent white;
    margin-left: 5px;
}

.video-info {
    padding: 1rem;
}

.video-title {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.video-title a {
    color: #2c3e50;
    text-decoration: none;
}

.video-title a:hover {
    color: #3498db;
    text-decoration: underline;
}

.channel-info {
    margin-bottom: 0.8rem;
    font-size: 0.9rem;
}

.channel-link {
    color: #e74c3c;
    text-decoration: none;
    display: inline-block;
    padding: 2px 8px;
    border-radius: 3px;
    background-color: #f8f9fa;
    border: 1px solid #e0e0e0;
    transition: all 0.2s;
}

.channel-link:hover {
    background-color: #e74c3c;
    color: white;
    border-color: #e74c3c;
}

.youtube-link {
    color: #e74c3c;
    text-decoration: none;
    display: inline-block;
    padding: 4px 10px;
    border-radius: 4px;
    background-color: #f8f9fa;
    border: 1px solid #e74c3c;
    transition: all 0.2s;
    font-size: 0.8rem;
}

.youtube-link:hover {
    background-color: #e74c3c;
    color: white;
}

.vimeo-link {
    color: #1ab7ea;
    text-decoration: none;
    display: inline-block;
    padding: 4px 10px;
    border-radius: 4px;
    background-color: #f8f9fa;
    border: 1px solid #1ab7ea;
    transition: all 0.2s;
    font-size: 0.8rem;
}

.vimeo-link:hover {
    background-color: #1ab7ea;
    color: white;
}

.video-description {
    font-size: 0.9rem;
    color: #666;
    line-height: 1.4;
    margin-top: 0.5rem;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
    text-overflow: ellipsis;
}
.thumbnail-link {
    display: block;
    text-decoration: none;
}

.loading {
    text-align: center;
    padding: 2rem;
    grid-column: 1 / -1;
}

footer {
    text-align: center;
    padding: 1rem;
    background-color: #2c3e50;
    color: white;
    margin-top: 2rem;
}

@media screen and (max-width: 768px) {
    .video-grid {
        grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    }
}

@media screen and (max-width: 480px) {
    .video-grid {
        /* 1列表示から2列表示に変更 */
        grid-template-columns: repeat(2, 1fr);
        gap: 10px; /* 狭い画面でのギャップを小さくする */
    }

    /* スマホ表示時のフォントサイズと余白を調整 */
    .video-title {
        font-size: 0.9rem;
        margin-bottom: 0.3rem;
    }
    
    .video-info {
        padding: 0.7rem;
    }
    
    /* サムネイルのplay-iconのサイズも調整 */
    .play-icon {
        width: 40px;
        height: 40px;
    }
    
    .play-icon:before {
        border-width: 8px 0 8px 16px;
    }
}