.menu-sidebar {
    position: fixed;
    top: 50%;
    left: 0;
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
    transform: translateY(-50%);
    z-index: 10;
}

.menu-sidebar__toggle {
    align-items: center;
    background-color: #fff;
    border: 1px solid #e6e6e6;
    border-left-size: 0px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.12);
    cursor: pointer;
    display: inline-flex;
    flex-direction: column;
    gap: 0.5rem;
    justify-content: center;
    padding: 1.2rem 0.8rem 1.2rem 0.2rem;
}

.menu-sidebar__toggle:hover,
.menu-sidebar__toggle:focus-visible {
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.16);
    outline: none;
}

.menu-sidebar__progress {
    display: flex;
    flex-direction: column;
    gap: 0.55rem;
}

.menu-sidebar__progress-segment {
    background-color: #cfd6de;
    border-radius: 999px;
    display: block;
    height: 4px;
    width: 22px;
}

.menu-sidebar__progress-segment.is-active {
    background-color: var(--memo-color-rust);
    box-shadow: 0 0 0 6px var(--memo-color-light-salmon);
}

.menu-sidebar__card {
    background-color: #fff;
    border: 1px solid #e6e6e6;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.12);
    max-height: calc(100vh - 140px);
    opacity: 0;
    overflow-y: auto;
    padding: 1rem 1.25rem;
    pointer-events: none;
    position: relative;
    transform: translateX(-6px);
    transition: opacity 0.2s ease, transform 0.2s ease;
    visibility: hidden;
    width: 260px;
}

.menu-sidebar.is-open .menu-sidebar__card {
    opacity: 1;
    pointer-events: auto;
    transform: translateX(0);
    visibility: visible;
}

.menu-sidebar__title {
    color: #7a7a7a;
    font-size: 0.85rem;
    font-weight: 700;
    letter-spacing: 0.08em;
    margin-bottom: 0.35rem;
    text-transform: uppercase;
}

.menu-sidebar__toc {
    font-size: 0.95rem;
    line-height: 1.35;
}

.menu-sidebar__toc .toc-list {
    list-style: none;
    margin: 0;
    padding: 0;
}

.menu-sidebar__toc .toc-list-item {
    margin: 0.15rem 0;
    padding: 0;
}

.menu-sidebar__toc .toc-link {
    color: inherit;
    display: block;
    padding: 0.35rem 0;
    text-decoration: none;
}

.menu-sidebar__toc .toc-link:focus,
.menu-sidebar__toc .toc-link:hover,
.menu-sidebar__toc .toc-link.is-active-link {
    color: var(--memo-color-rust);
    font-weight: 600;
    text-decoration: none;
}

.menu-sidebar__toc .toc-list .toc-list {
    border-left: 1px solid #e6e6e6;
    margin-left: 0.5rem;
    padding-left: 0.9rem;
}

:root[data-theme="dark"] .menu-sidebar__toggle,
:root[data-theme="dark"] .menu-sidebar__card {
    background-color: var(--memo-body-bg);
    border-color: var(--memo-border-color);
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.3);
}

:root[data-theme="dark"] .menu-sidebar__progress-segment {
    background-color: #626c76;
}

:root[data-theme="dark"] .menu-sidebar__toc .toc-list .toc-list {
    border-left-color: var(--memo-border-color);
}