:root {
    --red:         #E63946;
    --aqua:        #A8DADC;
    --light-blue:  #457B9D;
    --dark-blue:   #1D3557;
    }

    body {
    margin: 0;
    padding: 0;
    background-color: whitesmoke;
    color: var(--dark-blue);
    font-family: sans-serif;
    text-align: center;
    }

    /* Header SECTION */
    #hero {
        display: flex;
        flex-direction: column;
        flex-wrap: wrap;
        align-items: center;
        color: whitesmoke;
        text-shadow: 2px 2px 4px black;
        padding: 1rem;
        text-align: center;
    }

    .container {
        background-image: url(images/City.jpg);
        padding: 10%;
        background-size: cover;
        background-repeat: no-repeat;
        background-position: center;
        margin: 0;
        width: 100%;
        box-sizing: border-box;
    }

    .hero-title, .hero-subtitle {
        background: var(--dark-blue);
        padding: 5px 5px;
        border-radius: 5px;
        margin: 5px 0 10px 0;
    }

    .hero-subtitle {
        background: var(--light-blue);
    }

    /* Activities SECTION */
    .activity-section {
        justify-content: center;
        gap: 20px;
        margin: 20px 0;
        color: var(--dark-blue);
        padding: 1rem;
    }

    .guide-title {
        font-size: 140%;
        margin-top: 50px;
        margin-bottom: 40px;
    }

    .activities {
        display: flex;
        flex-direction: row;
        justify-content:center;
        gap: 1rem;
    }

    .left-side, .right-side {
        display: flex;
        flex-direction: column;
        align-items: center;
        justify-content: space-between;
        margin: 0 20px;
        width: 35%;
    }

    .activity-1, .activity-2, .activity-3, .activity-4 {
        max-width: 400px;
        width: 100%;
        text-align: center;
    }

    .activity-2, .activity-4 {
        margin-top: 20px;
    }

    .img-activity {
        width: 100%;
        max-width: 350px;
        height: auto;
        max-height: 250px;
        object-fit: cover;
        border-radius: 15px;
        border: 2px solid var(--light-blue);
    }

    .btn {
        background: var(--dark-blue);
        color: whitesmoke;
        border: none;
        padding: 10px 15px;
        border-radius: 5px;
        cursor: pointer;
    }

    .btn:hover {
    background: var(--aqua); /* or any color */
    transform: scale(1.1);
    opacity: 1;
    }


    /* Guide SECTION */
    .guide-section {
        display: flex;
        justify-content: center;
        align-items: center;
        margin: 50px 0;
        flex-direction: row;
    }

    .guide-img {
        width: 200px;
        object-fit: scale-down;
        margin-right: 10px;
    }

    .guide-text {
        width: 300px;
        text-align: center;
        margin: 0 auto;
    }

    .card {
        display: flex;
        flex-direction: row;
        align-items: center;
        padding: 20px;
        background: var(--aqua);
        border-bottom: 6px solid var(--dark-blue);
        border-radius: 10px;
    }



    /* GALLERY SECTION */

    .gallery-wrapper {
        display: flex;
        align-items: center;
        justify-content: center;
        margin: 10% auto;
    }

    .gallery {
    display: flex;
    gap: 16px;
    overflow-x: auto;
    scroll-behavior: smooth;
    
    }

    .gallery-img {
    height: 250px;
    max-width: 400px;
    object-fit: cover;
    border-radius: 12px;
    border: 2px solid var(--light-blue);
    transition: transform 0.3s ease;
    }

    #back-btn, #next-btn {
        width: 50px;
        margin: 40px;
        cursor: pointer;
        left: 8px;
        right: 8px;
    }

    .gallery::-webkit-scrollbar {
        display: none;

    }

    .gallery div img:hover {
        cursor: pointer;
        transform: scale(1.05);
    }

    .gallery div img{
        width: 100%;
    }

    .gallery div {
        width: 100%;
        display: grid;
        grid-template-columns: auto auto auto;
        grid-gap: 10px;
        padding: 10px;
        flex: none;
    }

    /* Footer SECTION */

    #back-to-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    padding: 0.85rem 0.85rem;
    background-color: var(--dark-blue);
    color: whitesmoke;
    border: none;
    border-radius: 45%;
    cursor: pointer;
    box-shadow: 0 2px 6px black;
    opacity: 0.8;
    transition: opacity 0.2s ease, transform 0.2s ease;
    }

    #back-to-top {
    display: none; 
    }

    body.scrolled #back-to-top {
    display: block;
    }

    #back-to-top:hover {
    background: var(--aqua); /* or any color */
    transform: scale(1.1);
    opacity: 1;
    }


    /* RESPONSIVE STYLES */
    @media (max-width: 600px) {
        .activities {
            flex-direction: column;
            align-items: center;
        }

        .activity-1, .activity-2, .activity-3, .activity-4 {
            max-width: 90%;
        }
        
        .img-activity {
            width: 100%;
            max-width: 60vw;
            height: auto;
            object-fit: cover;
            border-radius: 15px;
            border: 2px solid var(--light-blue);
    }

        .guide {
            flex-direction: column;
            text-align: center;
            padding: 1rem;
        }

        .card {
            flex-direction: column;
            align-items: center;
            text-align: center;
        }

        .guide-img {
            margin: 0 0 1rem 0;
            max-width: 200px;
        }

        .guide-text {
            max-width: 100%;
            padding: 0 1rem;
        }

        .hero-title {
            font-size: 1.5rem;
        }

        .hero-subtitle {
            font-size: 1rem;
        }

        .guide-title {
            font-size: 1.2rem;
        }

        .gallery div {
            width: 270%;
            display: grid;
            grid-template-columns: auto auto auto;
            grid-gap: 10px;
            padding: 20px;
            flex: none;
        }

        .left-side, .right-side {
            width: 100%;
        }

            #back-btn, #next-btn {
            display: none;
        }

        #back-to-top {
            bottom: 2rem;
            right: 1rem;
            padding: 0.6rem 0.8rem;
            font-size: 0.85rem;
        }
    }