.container {
    position: relative;
    width: 100%;
    height: auto;
    margin: 0 auto;
    overflow: hidden;
}

/* 背景画像を画面全体にフィット */
.big-image2,
.big-image {
    position: absolute;
    top: -100%;
    width: 100%;
    height: 200%;
    background-size: cover;
    background-position: center center;
    z-index: 10;
}

.big-image2 {
    background: url('../images/flash/your-big-image.jpg') no-repeat center center;
    animation: slideDownAndFadeOut 12s forwards;
}

.big-image {
    background: url('../images/flash/your-big-image2.jpg') repeat-y left top;
    background-size: 100% auto;
    animation: slideDown 8s 8s forwards;
}

/* アニメーション */
@keyframes slideDownAndFadeOut {
    0% {
        top: -100%;
        opacity: 1;
    }
    70% {
        top: -15%;
        opacity: 1;
    }
    80% {
        top: -15%;
        opacity: 0;
    }
    100% {
        top: -15%;
        opacity: 0;
    }
}

@keyframes slideDown {
    from {
        top: -100%;
    }
    to {
        top: 0%;
    }
}

.small-images-group-1,
.small-images-group-2 {
    position: relative;
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    width: 100%;
    margin-top: 10px;
    opacity: 1;
}

.small-image {
    width: 32%;
    height: 100px; /* スマホ画面に合わせて低めに */
    background-size: cover;
    background-position: center;
    opacity: 0;
    filter: brightness(0.7);
    transform: scale(1.2);
    transition: opacity 2s ease-in-out, filter 2s ease-in-out, transform 2s ease-in-out;
}

.small-image.fade-in {
    opacity: 1;
    filter: brightness(1);
    transform: scale(1);
}

.text-overlay {
    position: relative;
    margin-top: 10px;
    width: 100%;
    text-align: center;
    font-size: 1em;
    opacity: 0;
    transition: opacity 2s ease-in-out;
}

.text-overlay img {
    width: 90%;
    height: auto;
}