/* ============================================
   サンプル教材・動画
   ============================================ */
.materials-section {
    background-color: var(--color-white);
}
.materials-item {
    margin-bottom: 30px;
}

.materials-image {
    display: flex;
    justify-content: center;
    align-items: center;
    height: auto;  /* Changed from 200px */
    width: 100%;
}

.materials-image img {
    border-radius: 12px;
    /* filter: grayscale(100%); */
    /* transition: filter 0.4s ease; */
    max-width: 100%;
    height: auto;
}
/* 
.materials-item:hover .materials-image img {
    filter: grayscale(0%);
} */

.materials-name {
    font-size: 1.5rem;
    font-weight: 500;
    color: var(--color-primary);
}

.videos-section {
    background-color: var(--color-white);
}

.btn-youtube {
    max-width:fit-content;
}

.video-card {
    margin-bottom: 2rem;
}

.video-wrapper {
    position: relative;
    padding-bottom: 56.25%; /* 16:9 比率 */
    height: 0;
    overflow: hidden;
    margin-bottom: 1rem;
}

.video-wrapper iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    border-radius: 0.375rem;
}

/* ============================================
   レスポンシブ
   ============================================ */
@media (max-width: 991px) {
    section {
        padding: 60px 0;
    }

    /* Keep side-by-side layout on tablet/mobile */
    .materials-item .row {
        align-items: center;
    }

    .materials-name {
        font-size: clamp(1rem, 2.5vw, 18px);
    }

    .section-description {
        font-size: clamp(12px, 1.8vw, 0.9rem);
    }

    .btn-custom {
        padding: 3px 36px;
        font-size: 13px;
        margin-top: 30px;
    }
}

@media (max-width: 575px) {
    section {
        padding: 50px 0;
    }

    .materials-image img {
        max-width: 90%;  /* Slightly smaller on very small screens */
    }

    .materials-name {
        font-size: 15px;
    }

    .section-description {
        font-size: 12px;
        line-height: 1.5;
    }

    .btn-custom {
        padding: 3px 36px;
        font-size: 12px;
        margin-top: 20px;
    }
}