body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f4f4f4;
    color: #333;
}

header {
    background-color: #232f3e;
    color: #fff;
    padding: 1em 0;
    text-align: center;
}

header h1 {
    margin: 0;
}

header p {
    margin-top: 0.5em;
    font-size: 0.9em;
}

.amazon-associate-disclaimer {
    font-size: 0.8em;
    color: #ffd814; /* Amazon Prime yellow for visibility */
    margin-top: 5px;
}

#categories-grid,
#books-subcategories-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 20px;
    padding: 20px;
    max-width: 1200px;
    margin: 20px auto;
}

.category-card {
    background-color: #fff;
    border: 1px solid #ddd;
    border-radius: 8px;
    padding: 15px;
    text-align: center;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    transition: transform 0.2s;
    text-decoration: none;
    color: #333;
}

.category-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
}

.category-card .icon {
    font-size: 2em;
    margin-bottom: 10px;
}

.category-card h2 {
    font-size: 1.2em;
    margin: 0;
}

footer {
    background-color: #232f3e;
    color: #fff;
    text-align: center;
    padding: 1em 0;
    position: relative;
    bottom: 0;
    width: 100%;
    margin-top: 20px;
}

footer p {
    margin: 0.5em 0;
    font-size: 0.8em;
}

#prime-banner {
    background-color: #ffd814; /* Amazon Prime yellow */
    padding: 10px 0;
    text-align: center;
    font-weight: bold;
    font-size: 1.1em;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

#prime-banner a {
    text-decoration: none;
    color: #000; /* Black text for contrast */
    display: block;
    padding: 5px 0;
}

#prime-banner a:hover {
    background-color: #ffc400; /* Slightly darker yellow on hover */
}

header nav {
    display: flex;
    justify-content: center;
    padding-bottom: 10px;
}

header h1 {
    text-align: center;
    margin: 10px 0;
    font-size: 2em; /* Ensure consistent styling with the main h1 */
    color: #fff;
}

.navbar-form {
    margin: 10px auto;
    display: block; /* To center the form */
    width: fit-content; /* To ensure the margin auto works */
}

.navbar-form .form-control {
    background-color: #3a475a;
    border: 1px solid #4a5a6a;
    color: #fff;
    padding: 8px 12px;
    border-radius: 5px;
    width: 200px;
    transition: all 0.3s ease;
}

.navbar-form .form-control::placeholder {
    color: #bbb;
}

.navbar-form .form-control:focus {
    border-color: #ffd814;
    box-shadow: 0 0 0 0.2rem rgba(255, 216, 20, 0.25);
}

header nav a {
    color: #fff;
    text-decoration: none;
    margin: 0 10px;
    font-weight: bold;
    transition: color 0.2s;
}

header nav a:hover {
    color: #ffd814; /* Amazon Prime yellow */
}

footer a {
    color: #fff;
    text-decoration: none;
    transition: color 0.2s;
}

footer a:hover {
    color: #ffd814; /* Amazon Prime yellow */
}