/* ============================================================
   Layout - Page Structure, Bottom Navigation, Breadcrumbs
   ============================================================ */

/* ---- Page Container ---- */
.page {
    padding: var(--page-padding-top) var(--page-padding-x) var(--spacing-md);
    max-width: 600px;
    margin: 0 auto;
}

/* ---- Page Header ---- */
.page-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-sm);
    min-height: 36px;
}

.page-header h1 {
    flex: 1;
    min-width: 0;
}

/* ---- Bottom Navigation ---- */
.bottom-nav {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    height: calc(var(--nav-height) + var(--safe-area-bottom));
    padding-bottom: var(--safe-area-bottom);
    background: var(--section-bg);
    box-shadow: var(--nav-shadow);
    display: flex;
    align-items: stretch;
    justify-content: space-around;
    z-index: var(--z-nav);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
}

.bottom-nav__item {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 3px;
    flex: 1;
    padding: 6px 4px;
    color: var(--hint-color);
    font-size: var(--text-2xs);
    font-weight: var(--weight-medium);
    letter-spacing: 0.01em;
    cursor: pointer;
    border: none;
    background: none;
    transition: color var(--transition-fast);
    position: relative;
    -webkit-tap-highlight-color: transparent;
}

.bottom-nav__item.active {
    color: var(--button-color);
}

.bottom-nav__item.active::before {
    content: '';
    position: absolute;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 24px;
    height: 2px;
    background: var(--button-color);
    border-radius: 0 0 var(--radius-xs) var(--radius-xs);
}

.bottom-nav__item:active {
    opacity: 0.6;
}

.bottom-nav__icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 24px;
    height: 24px;
    font-size: 22px;
    line-height: 1;
    transition: transform var(--transition-fast);
}

.bottom-nav__icon svg {
    display: block;
}

.bottom-nav__item.active .bottom-nav__icon {
    transform: scale(1.1);
}

/* ---- Breadcrumbs ---- */
.breadcrumbs {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    font-size: var(--text-sm);
    color: var(--hint-color);
    margin-bottom: var(--spacing-sm);
    overflow-x: auto;
    white-space: nowrap;
    scrollbar-width: none;
    -ms-overflow-style: none;
    padding: var(--spacing-xs) 0;
}

.breadcrumbs::-webkit-scrollbar {
    display: none;
}

.breadcrumbs a {
    color: var(--link-color);
    font-weight: var(--weight-medium);
}

.breadcrumbs a:active {
    opacity: 0.6;
}

.breadcrumbs__separator {
    color: var(--hint-color);
    opacity: 0.5;
    font-size: var(--text-xs);
}

/* ---- Section Headers (for grouped list pages) ---- */
.section-header {
    font-size: var(--text-sm);
    font-weight: var(--weight-semibold);
    color: var(--section-header);
    text-transform: uppercase;
    letter-spacing: 0.04em;
    padding: var(--spacing-sm) 0 var(--spacing-xs);
}

/* ---- FAB (Floating Action Button) ---- */
.fab {
    position: fixed;
    bottom: calc(var(--nav-height) + var(--safe-area-bottom) + var(--fab-offset));
    right: var(--fab-offset);
    width: var(--fab-size);
    height: var(--fab-size);
    border-radius: var(--radius-round);
    background: var(--button-color);
    color: var(--button-text-color);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    font-weight: var(--weight-regular);
    line-height: 1;
    border: none;
    cursor: pointer;
    box-shadow: var(--fab-shadow);
    z-index: var(--z-fab);
    transition: transform var(--transition-fast),
                box-shadow var(--transition-fast);
    -webkit-tap-highlight-color: transparent;
}

.fab:active {
    transform: scale(0.92);
    box-shadow: var(--card-shadow);
}

.fab__icon {
    font-size: 28px;
    font-weight: 300;
}