/* --- Floating Sticky Tabs Dock for Lesson Pages --- */
#lessonTabsFloatingWrapper {
    position: fixed;
    z-index: 1020;
    box-sizing: border-box;
    background-color: #ffffff;
    border: 1px solid #dee2e6;
    border-top: none;
    border-radius: 0 0 10px 10px;
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.12);
    padding: 0;
    margin: 0;
    pointer-events: auto;
    -webkit-font-smoothing: subpixel-antialiased;
    -moz-osx-font-smoothing: auto;
}

#lessonTabsFloatingWrapper.is-hidden {
    transform: translateY(-100%);
    box-shadow: none;
    transition: transform 0.5s cubic-bezier(0.4, 0, 0.2, 1), box-shadow 0.35s ease;
}


#lessonTabsFloatingWrapper:not(.is-hidden) {
    transform: none;
    transition: transform 0.5s cubic-bezier(0.16, 1, 0.3, 1), box-shadow 0.3s ease;
}

#lessonTabsFloatingWrapper .lesson-tabs-floating-inner {
    display: flex;
    align-items: flex-start;
    width: 100%;
    margin: 0;
    padding: 0;
}

#lessonTabsFloatingWrapper .lesson-tabs-floating-list {
    display: flex;
    flex-wrap: wrap;
    flex: 1 1 auto;
    border: none;
    margin: 0;
    padding: 0;
    width: 100%;
    list-style: none;
}

#lessonTabsFloatingWrapper .lesson-tabs-floating-list .nav-item {
    margin: 0;
    padding: 0;
    flex: 0 0 auto;
}

#lessonTabsFloatingWrapper .lesson-tabs-floating-list .nav-link {
    display: block;
    width: 100%;
    text-align: center;
    white-space: nowrap;
    padding: 0.45rem 0.75rem;
    font-size: inherit;
    font-family: inherit;
    font-weight: normal;
    line-height: inherit;
    border: 1px solid #dee2e6;
    border-top: none;
    border-radius: 0 0 4px 4px;
    background-color: #ffffff;
    color: #337ab7;
    margin-top: 0;
    height: auto;
    -webkit-font-smoothing: subpixel-antialiased;
    -moz-osx-font-smoothing: auto;
    transition: background-color 0.15s ease, color 0.15s ease;
}

#lessonTabsFloatingWrapper .lesson-tabs-floating-list .nav-link:hover,
#lessonTabsFloatingWrapper .lesson-tabs-floating-list .nav-link:focus {
    background-color: #f8f9fa;
    color: #23527c;
}

#lessonTabsFloatingWrapper .lesson-tabs-floating-list .nav-link.active {
    background-color: #ffffff;
    color: #495057;
    font-weight: normal;
    border: 1px solid #dee2e6;
    border-top: 3px solid #337ab7;
    border-radius: 0 0 4px 4px;
    padding-top: 0.55rem;
    padding-bottom: 0.4rem;
    padding-left: 0.7rem;
    padding-right: 1rem;
    margin-top: 0;
    margin-bottom: -12px;
    height: auto;
    position: relative;
    z-index: 2;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.15);
    -webkit-font-smoothing: subpixel-antialiased;
    -moz-osx-font-smoothing: auto;
}

/* --- Floating Scroll-to-Top Button in bottom-right corner --- */
.lesson-scroll-top-btn {
    position: fixed;
    bottom: 28px;
    right: 28px;
    z-index: 1010;
    width: 46px;
    height: 46px;
    padding: 0;
    margin: 0;
    border-radius: 50%;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    background-color: rgba(255, 255, 255, 0.7);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    border: 2.5px solid rgba(108, 117, 125, 0.45);
    color: rgba(108, 117, 125, 0.85);
    box-shadow: 0 4px 14px rgba(0, 0, 0, 0.08);
    cursor: pointer;
    outline: none;
    user-select: none;
    opacity: 1;
    transform: translateY(0);
    transition: opacity 0.3s ease, transform 0.3s ease, background-color 0.2s ease, border-color 0.2s ease, color 0.2s ease, box-shadow 0.2s ease;
}

.lesson-scroll-top-btn.is-hidden {
    opacity: 0;
    pointer-events: none;
    transform: translateY(14px);
}

.lesson-scroll-top-btn:hover,
.lesson-scroll-top-btn:focus {
    background-color: rgba(255, 255, 255, 0.95);
    border-color: #337ab7;
    color: #337ab7;
    transform: translateY(-2px);
    box-shadow: 0 6px 18px rgba(51, 122, 183, 0.28);
}

.lesson-scroll-top-btn:active {
    transform: translateY(0);
}

.lesson-scroll-top-btn svg {
    margin-top: -1px;
}

@media (max-width: 767px) {
    .lesson-scroll-top-btn {
        bottom: 20px;
        right: 18px;
        width: 42px;
        height: 42px;
    }
}

#lessonTabsFloatingWrapper .lesson-tabs-pull-tab {
    display: none;
    position: absolute;
    left: 50%;
    top: 100%;
    transform: translateX(-50%);
    cursor: pointer;
    z-index: 1025;
    user-select: none;
    outline: none;
    line-height: 1;
    background: none;
    border: none;
    padding: 0;
}

#lessonTabsFloatingWrapper.is-hidden .lesson-tabs-pull-tab {
    display: block;
}

#lessonTabsFloatingWrapper .pull-tab-pill {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 3px 18px 4px 18px;
    background: #ffffff;
    border: 1px solid #dee2e6;
    border-top: none;
    border-radius: 0 0 10px 10px;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.12);
    color: #6c757d;
    transition: all 0.2s ease;
}

#lessonTabsFloatingWrapper .lesson-tabs-pull-tab:hover .pull-tab-pill,
#lessonTabsFloatingWrapper .lesson-tabs-pull-tab:focus .pull-tab-pill {
    background-color: #f8f9fa;
    color: #337ab7;
    padding-bottom: 6px;
    box-shadow: 0 6px 14px rgba(0, 0, 0, 0.18);
}