.sidemenu_container {
    --rail: 56px;
    --panel: 250px;
    --icon: 24px;
    width: var(--rail);
    background-color: var(--color-accent-hover);
    transition: width 0.2s ease;
}

.sidemenu {
    position: sticky;
    top: 0;
    z-index: 100;
    width: var(--rail);
    max-height: 100dvh;
    padding-block: 1rem;
    overflow: hidden auto;
    box-sizing: border-box;
    background-color: var(--color-accent-hover);
    interpolate-size: allow-keywords;
    transition: width 0.2s ease;
}

.sidemenu summary {
    list-style: none;
    cursor: pointer;
}

.sidemenu summary::-webkit-details-marker {
    display: none;
}

.sidemenu-header {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding-inline: calc((var(--rail) - var(--icon)) / 2);
    white-space: nowrap;
}

.sidemenu .icon {
    flex: none;
    width: var(--icon);
    height: var(--icon);
    object-fit: contain;
}

.icon-text {
    display: none;
    font-size: larger;
    font-weight: bold;
    text-decoration: underline;
}

/* desktop: hover or keyboard focus only, so a leftover [open] from mobile is ignored */
@media (hover: hover) and (pointer: fine) and (width > 45rem) {
    .sidemenu-header {
        pointer-events: none;
    }

    .sidemenu_container:is(:hover, :has(:focus-visible)),
    .sidemenu_container:is(:hover, :has(:focus-visible)) .sidemenu {
        width: var(--panel);
    }

    .sidemenu_container:is(:hover, :has(:focus-visible)) .sidemenu {
        border-right: 1px solid color-mix(in srgb, var(--color-border) 15%, transparent);
    }

    .sidemenu_container:is(:hover, :has(:focus-visible)) .icon {
        display: none;
    }

    .sidemenu_container:is(:hover, :has(:focus-visible)) .icon-text {
        display: inline;
    }

    .sidemenu_container .sidemenu::details-content {
        content-visibility: hidden;
    }

    .sidemenu_container:is(:hover, :has(:focus-visible)) .sidemenu::details-content {
        content-visibility: visible;
    }
}

/* touch and narrow screens: open by tapping the icon */
@media not all and (hover: hover) and (pointer: fine) and (width > 45rem) {
    .sidemenu_container:has(.sidemenu[open]),
    .sidemenu[open] {
        width: var(--panel);
    }

    .sidemenu[open] {
        border-right: 1px solid color-mix(in srgb, var(--color-border) 15%, transparent);
    }

    .sidemenu[open] .icon {
        display: none;
    }

    .sidemenu[open] .icon-text {
        display: inline;
    }
}

.sidemenu-item {
    margin: 1.5rem 1rem;
}

.sidemenu-option,
.sidemenu-item a {
    color: var(--color-text);
    text-decoration: none;
    font-size: large;
    transition: opacity 0.15s ease, transform 0.15s ease;
}

.sidemenu-option:hover,
.sidemenu-item a:hover {
    opacity: 0.7;
    transform: translateY(-1px);
}

.sidemenu-option {
    display: block;
    width: fit-content;
    border-bottom: 1px solid var(--color-border);
    white-space: nowrap;
}

.sidemenu-option::after {
    content: "";
    display: inline-block;
    margin-left: 0.35em;
    border: 0.35em solid transparent;
    border-top-color: currentColor;
    vertical-align: middle;
    transition: transform 0.15s ease;
}

.sidemenu-item[open] .sidemenu-option::after {
    transform: rotate(180deg);
}

.sidemenu-item::details-content {
    height: 0;
    overflow: clip;
    transition: height 0.25s ease, content-visibility 0.25s allow-discrete;
}

.sidemenu-item[open]::details-content {
    height: auto;
}

.sidemenu-item .drop-content {
    display: grid;
    gap: 0.5em;
    padding: 0.5em 0 0 1rem;
}

.sidemenu-item .drop-content .drop-option {
    padding: 0.25rem 0.75rem;
}

@media (max-width: 45rem) {
    .sidemenu_container,
    .sidemenu_container:has(.sidemenu[open]) {
        --panel: min(80vw, 250px);
        position: relative;
        width: 0;
        background: none;
    }

    .sidemenu_container:has(.sidemenu[open])::before {
        content: "";
        position: absolute;
        inset: 0 auto 0 0;
        z-index: 10;
        width: var(--panel);
        background-color: var(--color-accent-hover);
        box-shadow: 4px 0 16px rgb(0 0 0 / 0.2);
    }

    .sidemenu {
        padding-block: 0.75rem;
        border-radius: 0 0 8px 0;
    }

    .sidemenu[open] {
        border-radius: 0;
    }

    .sidemenu-item {
        margin: 1rem 0.75rem;
    }

    .sidemenu-option,
    .sidemenu-item a,
    .icon-text {
        font-size: 15px;
    }
}