/* ==========================================================
   BOOKS — BREADCRUMB ROW
   ========================================================== */


/* ==========================================================
   ROW

   Keep this row's contents aligned with the content edge of
   Masthead Thin.

   Masthead Thin:
   - max-width: 120rem
   - desktop inline padding: 3.6rem

   The background/rule remain full-width. Only the content
   alignment is constrained to the masthead's inner frame.
   ========================================================== */

.fr-books-mastheadRow {
    display: flex;
    align-items: center;
    justify-content: space-between;

    gap: 2rem;

    width: 100%;

    min-height: 4.8rem;

    padding:
            0.7rem
            max(
                    3.6rem,
                    calc(
                            (100% - 120rem) / 2
                            + 3.6rem
                    )
            );

    box-sizing: border-box;

    border-bottom:
            1px solid
            rgba(0, 0, 0, 0.12);

    background: var(--tb-bg);

    color: #444;
}


/* ==========================================================
   BREADCRUMB
   ========================================================== */

.fr-books-mastheadBreadcrumb {
    display: flex;
    align-items: center;

    flex-wrap: wrap;

    gap: 0.55rem;

    min-width: 0;

    margin: 0;
    padding: 0;

    font-family:
            Arial,
            Helvetica,
            sans-serif;

    font-size: 1.35rem;
    font-weight: 400;

    line-height: 1.3;
}


.fr-books-mastheadBreadcrumb
.fr-books-breadcrumb-link,
.fr-books-mastheadBreadcrumb
.fr-books-breadcrumb-current,
.fr-books-mastheadBreadcrumb
.fr-books-breadcrumb-item,
.fr-books-mastheadBreadcrumb
.fr-books-breadcrumb-pages {
    color: #555;

    text-decoration: none;
}


.fr-books-mastheadBreadcrumb
.fr-books-breadcrumb-link:not([aria-disabled="true"]):hover {
    color: var(--tb-accent-dark);

    text-decoration: underline;

    text-underline-offset: 0.2em;
}

.fr-books-mastheadBreadcrumb
.fr-books-breadcrumb-link[aria-disabled="true"] {
    cursor: default;
}


/* ==========================================================
   CHAPTER / ITEM TYPOGRAPHY
   ========================================================== */

.fr-books-mastheadBreadcrumb
.fr-books-breadcrumb-current,
.fr-books-mastheadBreadcrumb
.fr-books-breadcrumb-item {
    color: #222;

    font-style: italic;
    font-weight: 400;
}


/* ==========================================================
   CURRENT CRUMB

   LIST:
   LIBRARY

   BOOK:
   Book title

   CHAPTER:
   Chapter title

   MOSAIC ITEM:
   Item title
   ========================================================== */


/* Library is current until a real book is present */

.fr-books-mastheadBreadcrumb
[data-books-breadcrumb-all] {
    font-weight: 700;
}


/* Once a book is present, Library is no longer current */

.fr-books-mastheadBreadcrumb:has(
    #fr-books-breadcrumb-book:not(.is-placeholder)
)
[data-books-breadcrumb-all] {
    font-weight: 400;
}


/* Book is current on the book page */

.fr-books-mastheadBreadcrumb
#fr-books-breadcrumb-book:not(.is-placeholder) {
    font-weight: 700;
}


/* Once a real chapter is present, book is no longer current */

.fr-books-mastheadBreadcrumb:has(
    #fr-books-breadcrumb-title:not(.is-placeholder)
)
#fr-books-breadcrumb-book {
    font-weight: 400;
}


/* Chapter is current on an ordinary chapter page */

.fr-books-mastheadBreadcrumb
#fr-books-breadcrumb-title:not(.is-placeholder) {
    font-weight: 700;
}


/* Once a mosaic item is present, chapter is no longer current */

.fr-books-mastheadBreadcrumb:has(
    #fr-books-breadcrumb-item:not([hidden])
)
#fr-books-breadcrumb-title {
    font-weight: 400;
}


/* Mosaic item is current */

.fr-books-mastheadBreadcrumb
#fr-books-breadcrumb-item:not([hidden]) {
    font-weight: 700;
}


/* ==========================================================
   SEPARATORS
   ========================================================== */

.fr-books-mastheadBreadcrumb
.fr-books-breadcrumb-separator,
.fr-books-mastheadBreadcrumb
.fr-books-breadcrumb-itemSeparator {
    color: #aaa;

    font-weight: 400;
}


/* ==========================================================
   PLACEHOLDERS
   ========================================================== */

.fr-books-mastheadBreadcrumb
.is-placeholder {
    opacity: 0.52;
}


/* ==========================================================
   PAGES
   ========================================================== */

.fr-books-mastheadBreadcrumb
.fr-books-breadcrumb-pages {
    margin-left: 0.35rem;

    color: #777;

    font-size: 1.2rem;
    font-weight: 400;

    white-space: nowrap;
}


/* ==========================================================
   READER ACTIONS
   ========================================================== */

.fr-books-mastheadActions {
    display: flex;
    align-items: center;
    justify-content: flex-end;

    flex: 0 0 auto;

    min-width: max-content;
}


/* ==========================================================
   KEEP EXISTING USER ACTION CONTROLS COMPACT
   ========================================================== */

.fr-books-mastheadActions
.fr-reader-userActions,
.fr-books-mastheadActions
.fr-readers-userActions {
    display: flex;
    align-items: center;

    gap: 0.8rem;

    margin: 0;
}


/* ==========================================================
   MEDIUM DESKTOP

   Match Masthead Thin's 1180px gutter.
   ========================================================== */

@media (max-width: 1180px) {

    .fr-books-mastheadRow {
        padding:
                0.7rem
                2.4rem;
    }
}


/* ==========================================================
   TABLET

   Match Masthead Thin's 960px gutter.
   ========================================================== */

@media (max-width: 960px) {

    .fr-books-mastheadRow {
        padding:
                0.7rem
                2rem;
    }
}


/* ==========================================================
   SMALL TABLET
   ========================================================== */

@media (max-width: 900px) {

    .fr-books-mastheadBreadcrumb {
        font-size: 1.25rem;
    }
}


/* ==========================================================
   MOBILE

   Match Masthead Thin's 620px gutter.
   ========================================================== */

@media (max-width: 620px) {

    .fr-books-mastheadRow {
        align-items: flex-start;

        gap: 1rem;

        padding:
                0.8rem
                1.4rem;
    }


    .fr-books-mastheadBreadcrumb {
        gap: 0.4rem;

        font-size: 1.15rem;
    }


    .fr-books-mastheadActions {
        padding-top: 0.05rem;
    }
}