:root {
    --bg-color: #ffffff;
    --text-color: #333333;
    --btn-bg: #1A6600;
    --btn-text: #ffffff;
    --box-bg: #E0F4F1;
    --title-color: #2980b9;
}

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

body {
    font-family: 'Arial', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
}

header {
    padding: 20px;
    text-align: right;
    position: fixed;
    top: 0;
    right: 0;
    z-index: 1000;
}

#main-nav {
    background-color:#1a6600  ;
    position: fixed;
    top: 60px;
    left: 0;
    right: 0;
    z-index: 999;
    transition: background-color 0.3s ease;
    border-radius: 15px;
    box-shadow: 15px 14px 10px 0 rgba(0, 0, 0, 0.2);
    border-radius: 15px;
}

#main-nav ul {
    border-radius: 15px;
    background-color:rgb(61, 128, 61)  ;
    display: flex;
    justify-content: center;
    list-style-type: none;
    padding: 0;
    margin: 0;
}

#main-nav li {
    margin: 0 15px;
}

#main-nav a {
    color: var(--btn-text);
    text-decoration: none;
    padding: 15px 10px;
    display: block;
    font-weight: bold;
    transition: color 0.3s ease;
}

#main-nav a:hover {
    color: #021407;
}



main {
    padding-top: 120px;
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

h1 {
    text-align: center;
    margin-bottom: 30px;
    color: var(--title-color);
    font-size: 2.5rem;
}

.central-image {
    text-align: center;
    margin-bottom: 40px;
}

.central-image img {
    max-width: 100%;
    height: auto;
    border-radius: 10px;
}

.columns {
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
}

.column {
    flex: 1;
    min-width: 300px;
    margin: 10px;
}

.box {
    background-color: #b7f5d1;
    border-radius: 10px;
    padding: 20px;
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    transition: transform 0.3s ease;
    box-shadow: 15px 14px 10px 0 rgba(0, 0, 0, 0.2);
    align-items: center;
}

img {
    max-width: 400PX;
    border-radius: 5px;
    align-items: center;
}

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

h2 {
    color:rgb(90, 13, 28) ;
    margin-bottom: 15px;
    font-size: 1.5rem;
    text-align: center;
}

p {
    font-size: 1.1rem;
    margin-bottom: 20px;
    text-align: center;
    font-weight: 600;
}   

.btn {
    display: inline-block;
    background-color: var(--btn-bg);
    color: var(--btn-text);
    text-decoration: none;
    padding: 10px 20px;
    border-radius: 25px;
    transition: background-color 0.3s ease;
    text-align: center;
}

.btn:hover {
    background-color: #cb7246;
}


@media (max-width: 768px) {
    #main-nav ul {
        flex-direction: column;
        align-items: center;
    }

    #main-nav li {
        margin: 5px 0;
    }

    main {
        padding-top: 200px;
    }

    .columns {
        flex-direction: column;
    }
    
    .column {
        margin-bottom: 20px;
    }
}

.back-to-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    background-color: var(--btn-bg);
    color: rgb(175, 236, 124);
    width: 50px;
    height: 50px;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    box-shadow: var(--box-shadow);
    opacity: 0;
    transition: var(--transition);
    pointer-events: none;
}

.back-to-top.visible {
    opacity: 1;
    pointer-events: auto;
}