body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol";
    margin: 0;
    padding: 0;
    background-color: #F8F8F8; /* Lighter background */
    color: #333;
    line-height: 1.6;
}

header {
    background-color: #FF69B4; /* Keep pink header */
    color: white;
    padding: 1.5em 0; /* More padding */
    text-align: center;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.08); /* Softer shadow */
}

header h1 {
    margin: 0;
    font-size: 2.8em;
    font-weight: 600; /* Slightly bolder */
}

header p {
    margin: 0.5em 0;
    font-size: 1.2em;
    opacity: 0.9;
}

.categories {
    text-align: center;
    padding: 1.2em 0; /* More padding */
    background-color: #fff;
    border-bottom: 1px solid #EAEAEA; /* Lighter border */
    box-shadow: 0 1px 2px rgba(0, 0, 0, 0.04);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.categories a {
    text-decoration: none;
    /* color and border will be set specifically for each category below */
    padding: 0.8em 1.8em;
    margin: 0 0.6em;
    border-radius: 25px;
    transition: background-color 0.3s ease, color 0.3s ease, box-shadow 0.3s ease;
    font-weight: 500;
    /* Remove generic border here to allow specific colors */
}

/* Specific styles for each category link */
.categories a[href="#red"] {
    color: #CC0000; /* Darker red */
    border: 1px solid #CC0000;
}

.categories a[href="#red"]:hover {
    background-color: #CC0000;
    color: white;
    box-shadow: 0 2px 6px rgba(204, 0, 0, 0.4);
}

.categories a[href="#blue"] {
    color: #0066CC; /* Darker blue */
    border: 1px solid #0066CC;
}

.categories a[href="#blue"]:hover {
    background-color: #0066CC;
    color: white;
    box-shadow: 0 2px 6px rgba(0, 102, 204, 0.4);
}

.categories a[href="#green"] {
    color: #008000; /* Darker green */
    border: 1px solid #008000;
}

.categories a[href="#green"]:hover {
    background-color: #008000;
    color: white;
    box-shadow: 0 2px 6px rgba(0, 128, 0, 0.4);
}

.categories a[href="#pink"] {
    color: #FF69B4; /* Header pink, for emphasis */
    border: 1px solid #FF69B4;
}

.categories a[href="#pink"]:hover {
    background-color: #FF69B4;
    color: white;
    box-shadow: 0 2px 6px rgba(255, 105, 180, 0.4);
}

.gallery-container {
    max-width: 1280px; /* Wider container */
    margin: 3em auto; /* More margin */
    padding: 0 2em; /* More padding */
}

.category-section {
    background-color: #fff;
    padding: 2.5em;
    margin-bottom: 3em;
    border-radius: 12px;
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.06);
}

#red {
    background-color: #FFF0F0; /* Very light red */
}

#blue {
    background-color: #F0F8FF; /* Very light blue */
}

#green {
    background-color: #F0FFF0; /* Very light green */
}

#pink {
    background-color: #FFF5FA; /* Very light pink */
}

.category-section h2 {
    text-align: center;
    color: #FF69B4; /* Pink heading */
    margin-top: 0;
    margin-bottom: 2em; /* More space below heading */
    font-size: 2.2em;
    font-weight: 600;
}

.image-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); /* Slightly larger min-width for cards */
    gap: 25px; /* More gap */
    justify-content: center;
}

.image-card {
    background-color: #fff;
    border: 1px solid #F0F0F0; /* Lighter border */
    border-radius: 10px; /* Softer rounded corners */
    overflow: hidden;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.05); /* Lighter shadow */
    transition: transform 0.2s ease, box-shadow 0.2s ease;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.image-card:hover {
    transform: translateY(-8px); /* More pronounced lift */
    box-shadow: 0 12px 25px rgba(0, 0, 0, 0.12); /* More pronounced shadow */
}

.image-card img {
    width: 100%;
    height: auto; /* Allow image to take its natural height */
    display: block;
    border-bottom: 1px solid #F0F0F0;
}

.image-card a {
    display: block;
    width: calc(100% - 20px); /* Adjust to padding */
    padding: 12px;
    text-align: center;
    background-color: #FDFDFD; /* Almost white background for link */
    color: #FF69B4; /* Pink text for link */
    text-decoration: none;
    font-weight: 500; /* Medium weight */
    transition: background-color 0.3s ease, color 0.3s ease;
}

.image-card a:hover {
    background-color: #FF69B4; /* Darker pink on hover */
    color: white;
}

footer {
    text-align: center;
    padding: 2em 0; /* More padding */
    background-color: #222; /* Darker footer */
    color: #AAA; /* Lighter text */
    margin-top: 4em; /* More margin */
    font-size: 0.9em;
}

/* Add basic responsive adjustments for smaller screens */
@media (max-width: 768px) {
    header h1 {
        font-size: 2em;
    }

    header p {
        font-size: 1em;
    }

    .categories {
        flex-direction: column;
        padding: 1em 0;
    }

    .categories a {
        margin: 0.5em 0;
        padding: 0.6em 1.2em;
        width: 80%; /* Make buttons wider on small screens */
        box-sizing: border-box; /* Include padding and border in the element's total width */
    }

    .gallery-container {
        margin: 2em auto;
        padding: 0 1em;
    }

    .category-section {
        padding: 1.5em;
        margin-bottom: 2em;
    }

    .category-section h2 {
        font-size: 1.8em;
        margin-bottom: 1.5em;
    }

    .image-grid {
        grid-template-columns: 1fr; /* Stack images vertically on very small screens */
        gap: 20px;
    }
}

/* Adjustments for even smaller screens */
@media (max-width: 480px) {
    .categories a {
        font-size: 0.9em;
        padding: 0.5em 1em;
    }

    footer {
        padding: 1.5em 0;
        font-size: 0.8em;
    }
}