.book-popup-backdrop {
    position: fixed;
    inset: 0;
    z-index: 99999;
    background: rgba(15, 23, 42, 0.55);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 18px;
    backdrop-filter: blur(2px);
}

.book-popup-backdrop[hidden] {
    display: none;
}

.book-popup-open {
    overflow: hidden;
}

.book-popup-card {
    position: relative;
    width: min(520px, 100%);
    background: rgba(255, 255, 255, 0.96);
    border: 1px solid rgba(255, 255, 255, 0.65);
    border-radius: 22px;
    box-shadow: 0 22px 70px rgba(0, 0, 0, 0.28);
    padding: 26px 22px 18px;
    text-align: center;
    animation: bookPopupIn .18s ease-out;
}

@keyframes bookPopupIn {
    from {
        opacity: 0;
        transform: translateY(10px) scale(.97);
    }
    to {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

.book-popup-close {
    position: absolute;
    top: 10px;
    right: 12px;
    width: 34px;
    height: 34px;
    border: none;
    border-radius: 50%;
    background: rgba(15, 23, 42, 0.08);
    color: #334155;
    font-size: 1.35rem;
    line-height: 1;
    cursor: pointer;
    transition: background-color .15s ease, transform .12s ease;
}

.book-popup-close:hover {
    background: rgba(15, 23, 42, 0.14);
}

.book-popup-close:active {
    transform: scale(.96);
}

.book-popup-icon {
    font-size: 2rem;
    line-height: 1;
    margin-bottom: 8px;
}

.book-popup-title {
    margin: 0 0 12px;
    font-size: 1.25rem;
    font-weight: 800;
    color: #0f172a;
}

.book-popup-body {
    color: #334155;
    font-size: .98rem;
    line-height: 1.55;
}

.book-popup-line + .book-popup-line {
    margin-top: 8px;
}

.book-popup-actions {
    margin-top: 18px;
    display: flex;
    justify-content: center;
}