/* Layout & Container Spacing */
.books-container {
    padding-top: 1.5rem;
    padding-bottom: 1.5rem;
}

/* Introduction Box - Safely handles background image past strict server CSP */
.intro-box {
    background-image: url('/backgrounds/lightgrey.jpg');
    background-size: cover;
    background-repeat: no-repeat;
    padding: 25px;
    border-radius: 8px;
    color: #212529; /* Ensures high contrast, readable dark text on the light background */
    font-size: 1.1rem;
    line-height: 1.7;
    box-shadow: 0 4px 15px rgba(0,0,0,0.2);
}

/* Affiliate/Banner Branding Segment Card */
.affiliate-section {
    margin-top: 3rem;
    padding: 20px;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 8px;
}

.affiliate-logos img {
    max-width: 100%;
    height: auto;
    margin: 10px;
}

.affiliate-text {
    font-size: 0.95rem;
    color: #cbd5e1;
}
/* Books Sidebar Panel Wrapper Frame */
.books-sidebar-box {
    background-color: #22252a;
    border: 2px solid rgba(255, 255, 255, 0.2);
    border-radius: 8px;
    padding: 15px 10px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.3);
    text-align: center;
}

/* Books Sidebar Image Parameters (Replaces banned inline rules) */
.books-sidebar-img {
    width: 180px;
    height: 120px;
    margin: 10px auto 14px auto;
    display: block;
    object-fit: cover;
}

/* Modern Vertical Nav Pill System Rules */
.books-tab-nav .nav-link {
    color: #cbd5e1 !important;
    text-align: center;
    padding: 10px 15px;
    font-size: 1.05rem;
    transition: background-color 0.15s, color 0.15s;
}

.books-tab-nav .nav-link:hover {
    background-color: rgba(255, 255, 255, 0.08);
    color: #fff !important;
}