.hero-section-img {
    position: relative;
    height: 100vh;
    overflow: hidden;
}

.hero-bg-img {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: url('https://caesar-cdn.b-cdn.net/Content/banner_trangchu/congnghe.jpg') no-repeat center center/cover;
    animation: kenburns-img 6s ease-in-out infinite alternate;
    z-index: -1;
}

@keyframes kenburns-img {
    from {
        transform: scale(1) translate(0, 0);
    }

    to {
        transform: scale(1.1) translate(0, -2%);
    }
}

.overlayCN-img {
    position: absolute;
    top: 50%;
    left: 0;
    right: 0;
    transform: translateY(-50%);
    color: #fff;
    text-align: center;
    z-index: 2;
    justify-content: center;
    align-items: center;
}

.side-menu-img {
    position: absolute;
    top: 50%;
    left: 20px;
    transform: translateY(-50%);
    z-index: 3;
}

/* Nút bấm cách xuống */
#heroContentImgCN .btnslide {
    margin-top: 15px; /* cách xuống thêm */
}
.overlayCN-img h2 {
    font-size: 42px;
    color: #fff;
    opacity: 0;
    transform: translateX(-50px) scale(0.9);
    animation: slideZoomIn 1.8s ease forwards;
}

@keyframes slideZoomIn {
    0% {
        opacity: 0;
        transform: translateX(-50px) scale(0.9);
    }

    60% {
        opacity: 1;
        transform: translateX(10px) scale(1.05);
    }

    100% {
        opacity: 1;
        transform: translateX(0) scale(1);
    }
}
/* Hiệu ứng hover */
.btnslide:hover {
    background: #fff;
    color: #000 !important; /* ép chữ đen */
    transform: scale(1.05); /* hơi phóng to */
    box-shadow: 0 4px 12px rgba(0,0,0,0.3);
}
/* Hiệu ứng khi click (ép lại nhẹ) */
.btnslide:active {
    transform: scale(0.95);
}