/* Global style */
body {
    font-family: 'Georgia', serif;
    margin: 0;
    padding: 0;
    background: linear-gradient(to bottom, #f5f0e6, #e0d9c8);
    color: #333;
}

/* Header with image */
header {
    background-image: url('https://images.unsplash.com/photo-1524995997946-a1c2e315a42f?crop=entropy&cs=tinysrgb&fit=max&fm=jpg&w=1080&q=80'); 
    background-size: cover;
    background-position: center;
    height: 300px;
    position: relative;
}

.header-overlay {
    background-color: rgba(0, 0, 0, 0.6);
    height: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
}

header h1 {
    color: #fff;
    font-size: 40px;
    text-transform: uppercase;
    text-align: center;
    letter-spacing: 1px;
}

/* Calculator section */
.calculator {
    padding: 50px 40px;
    text-align: center;
    font-size: 30px;
}

/* Enlarge dropdowns */
.calculator select {
    font-size: 20px;
    padding: 10px 12px;
    margin: 0 8px;
    border-radius: 6px;
    border: 1px solid #ccc;
    min-width: 150px;
    cursor: pointer;
    font-family: "Segoe UI Emoji", "Noto Color Emoji", "Apple Color Emoji", Arial, sans-serif;
}

/* Result and books */
#result {
    margin-top: 25px;
    font-size: 28px;
    font-weight: bold;
    color: #4b2e2e;
}

.books-container {
    margin-top: 20px;
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 15px;
}

.book-card {
    cursor: pointer;
    transition: transform 0.2s;
}

.book-card img {
    width: 120px;
    height: 180px;
    object-fit: cover;
    border-radius: 8px;
    box-shadow: 0px 3px 6px rgba(0,0,0,0.3);
}

.book-card:hover {
    transform: scale(1.05);
}

/* Responsive */
@media (max-width: 600px) {
    header h1 {
        font-size: 36px;
    }

    #result {
        font-size: 22px;
    }

    .book-card img {
        width: 90px;
        height: 135px;
    }

    .calculator {
        font-size: 16px;
    }
}