html {
    overflow-x: hidden;
}

body {
    background-color: #f4f4f4;
    color: #333;
    font-family: Arial, sans-serif;
    line-height: 1.6;
    margin: 0;
    overflow-x: hidden;
    padding: 0;
}

header {
    background-color: #1a5f5f;
    /* Deep teal (blend of dark green + dark blue) */
    color: white;
    padding: 20px 0px;
    text-align: center;
    width: 100%;
}

header div {
    background-color: white;
    width: 100%;
}

header img {
    max-width: 800px;
}

nav {
    background-color: #0d3d3d;
    /* Darker teal for nav */
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2);
    padding: 15px;
    position: sticky;
    text-align: center;
    top: 0;
    z-index: 1000;
}

nav a {
    color: white;
    font-weight: bold;
    margin: 0 15px;
    text-decoration: none;
}

nav a:hover {
    text-decoration: underline;
}

section {
    background-color: white;
    border-radius: 8px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    margin: 20px auto;
    max-width: 800px;
    padding: 20px;
}

h1,
h2 {
    color: #1a5f5f;
    /* Teal headings */
}

ul {
    list-style-type: disc;
    padding-left: 20px;
}

footer {
    background-color: #0d3d3d;
    color: white;
    padding: 10px;
    text-align: center;
}

.highlight {
    background-color: #e3f2f2;
    /* Soft teal highlight */
    border-left: 5px solid #1a5f5f;
    border-radius: 4px;
    margin: 15px 0;
    padding: 15px;
}

.img {
    background-color: gray;
    background-position: center;
    background-size: cover;
    min-height: 200px;
    width: 100%;
}

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

/* Smooth scrolling */
html {
    scroll-behavior: smooth;
}

.unit-gallery {
    margin-top: 2.5rem;
    padding: 1.5rem;
    background: #f8f9fa;
    /* light background to separate it */
    border-radius: 8px;
}

.unit-gallery h3 {
    margin-top: 0px;
}

.tab-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
}

.tab-link {
    background: #e0e0e0;
    border: none;
    padding: 0.8rem 1.5rem;
    cursor: pointer;
    font-weight: 600;
    border-radius: 6px 6px 0 0;
    transition: all 0.2s;
}

.tab-link:hover {
    background: #d0d0d0;
}

.tab-link.active {
    background: #4a90e2;
    /* or your accent color */
    color: white;
}

.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
}

.gallery {
    display: flex;
    max-width: 100%;
}

.large-photo {
    margin-right: 1rem;
    width: 80%;
}

.large-photo img {
    background-color: gray;
    border-radius: 8px;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.15);
    max-height: 250px;
    min-height: 100%;
    min-width: 100%;
    object-fit: cover;
    transition: transform 0.2s;
}

.small-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    /* 2 columns */
    gap: 1rem;
    width: calc(100% - 33%);
}

.small-grid img {
    aspect-ratio: 4/3;
    background-color: gray;
    border-radius: 6px;
    height: auto;
    object-fit: cover;
    transition: transform 0.2s;
    width: 100%;
}

.small-grid img:hover,
.large-photo img:hover {
    transform: scale(2);
}

@media (max-width: 800px) {
    img {
        width: 100%;
    }

    header {
        padding: 0.1px;
    }

    .row {
        flex-direction: column;
    }


    .row .img:last-of-type {
        border-bottom: 0px solid white;
    }

    .row .img {
        border-bottom: 5px solid white;
    }
}

/* Responsive: stack on very small screens */
@media (max-width: 480px) {
    .tab-buttons {
        flex-direction: column;
    }

    .small-grid {
        grid-template-columns: 1fr;
        /* 1 column on tiny screens */
    }
}