.flipbook-shell {
    min-height: calc(100vh - 120px);
    padding: 1.5rem;
    display: flex;
    align-items: stretch;
    justify-content: center;
    background: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);
}

.flipbook-frame {
    width: 100%;
    min-height: calc(100vh - 160px);
    border: none;
    border-radius: 1.25rem;
    box-shadow: 0 24px 60px rgba(15, 23, 42, 0.45);
    background-color: #0f172a;
}

.flipbook-empty {
    background: rgba(15, 23, 42, 0.65);
    border-radius: 1.25rem;
    padding: 3rem 2rem;
    color: #e2e8f0;
    box-shadow: 0 24px 60px rgba(15, 23, 42, 0.45);
}

.flipbook-empty i {
    font-size: 3rem;
}

.flipbook-empty p {
    color: #cbd5f5;
}

@media (max-width: 767.98px) {
    .flipbook-shell {
        padding: 1rem;
    }

    .flipbook-frame {
        min-height: calc(100vh - 140px);
        border-radius: 0.75rem;
    }
}