:root {
    --reference-border: #aebbce;
    --reference-background: #f8fafc;
    --reference-control-background: #e2e8f0;
    --reference-accent: #64748b;
    --reference-theorem-hover: #e8edf3;
}

html {
    scroll-behavior: smooth;
}

body {
    padding-bottom: 33.33vh;
}

/* ── reference section ─────────────────────── */

.references {
    margin-top: 56px;
    padding: 0 4px 12px;
}

.references-title {
    display: flex;
    align-items: center;
    gap: 10px;
    margin: 0 0 4px;
    font-size: 24px;
    font-weight: 700;
    color: var(--text-color);
    letter-spacing: 0.6px;
    padding-bottom: 12px;
    border-bottom: 1px solid var(--border-color-light);
}
.reference-list {
    display: flex;
    flex-direction: column;
    gap: 6px;
    margin-top: 20px;
}

/* ── item ──────────────────────────────────── */

.reference-item {
    border-left: 2px solid transparent;
    background: transparent;
    border-radius: 8px;
    transition: background 0.25s ease, border-color 0.25s ease,
                box-shadow 0.25s ease;
    scroll-margin-top: 24px;
}
.reference-item:hover,
.reference-item[open] {
    background: var(--reference-background);
    border-left-color: var(--reference-border);
}
.reference-item > summary {
    list-style: none;
    cursor: pointer;
    user-select: none;
    display: flex;
    align-items: stretch;
    gap: 14px;
    padding: 14px 18px;
    border-radius: 8px;
}
.reference-item > summary::-webkit-details-marker {
    display: none;
}

/* ── index (number) ────────────────────────── */

.reference-index {
    flex-shrink: 0;
    min-width: 26px;
    display: grid;
    place-items: center;
    font-family: serif;
    font-size: 18px;
    font-weight: 800;
    color: var(--text-color);
    transition: color 0.25s ease;
}
.reference-item:hover .reference-index,
.reference-item[open] .reference-index {
    color: var(--reference-accent);
}

/* ── main (title + subtitle) ───────────────── */

.reference-main {
    flex: 1;
    min-width: 0;
    display: flex;
    flex-direction: column;
    gap: 2px;
}
.reference-label {
    font-size: 16px;
    font-weight: 550;
    color: var(--text-color);
    line-height: 1.5;
}
.reference-subtitle {
    font-family: system-ui, -apple-system, sans-serif;
    font-size: 12.5px;
    font-weight: 400;
    line-height: 1.5;
    color: var(--text-muted);
}

/* ── info button ───────────────────────────── */

.reference-info {
    all: unset;
    align-self: center;
    flex-shrink: 0;
    width: 28px;
    height: 28px;
    box-sizing: border-box;
    display: grid;
    place-items: center;
    color: var(--text-muted);
    background: transparent;
    border-radius: 50%;
    cursor: pointer;
    opacity: 0;
    transform: translateX(8px);
    pointer-events: none;
    transition: opacity 0.2s ease, transform 0.2s ease,
                color 0.25s ease, background 0.25s ease;
}
.reference-info .codicon {
    font-size:18px
}
.reference-item:hover > summary .reference-info,
.reference-item[open] > summary .reference-info {
    opacity: 1;
    transform: translateX(0);
    pointer-events: auto;
    color: var(--reference-accent);
}
.reference-item:hover > summary .reference-info:hover,
.reference-item[open] > summary .reference-info:hover {
    color: var(--text-color);
}
.reference-info:focus-visible {
    opacity: 1;
    pointer-events: auto;
    outline: 2px solid var(--reference-accent);
    outline-offset: 2px;
}

/* ── toggle (chevron) ──────────────────────── */

.reference-toggle {
    align-self: center;
    flex-shrink: 0;
    width: 28px;
    height: 28px;
    display: grid;
    place-items: center;
    color: var(--text-muted);
    background: transparent;
    border-radius: 50%;
    transition: transform 0.3s cubic-bezier(0.2, 0.8, 0.2, 1),
                color 0.25s ease;
}
.reference-toggle .codicon {
    font-size:18px
}
.reference-item:hover > summary .reference-toggle,
.reference-item[open] > summary .reference-toggle {
    color: var(--reference-accent);
}
.reference-item[open] > summary .reference-toggle {
    transform: rotate(180deg);
}

/* ── native <dialog> ───────────────────────── */

.reference-info-dialog {
    border: none;
    border-radius: 12px;
    padding: 0;
    width: min(480px, calc(100vw - 48px));
    max-height: calc(100vh - 48px);
    overflow: auto;
    box-shadow: 0 16px 48px -8px rgba(15, 23, 42, 0.25);
    color: var(--text-color);
    font-family: inherit;
}
.reference-info-dialog::backdrop {
    background: rgba(15, 23, 42, 0.4);
}
.reference-info-dialog[open] {
    animation: ref-dialog-in 0.2s cubic-bezier(0.2, 0.8, 0.2, 1);
}

.reference-info-dialog-body {
    position: relative;
    padding: 28px 32px;
}

.reference-info-dialog-title {
    font-size: 17px;
    font-weight: 700;
    margin: 0 0 16px;
    padding-bottom: 12px;
}

.reference-info-dialog-close {
    position: absolute;
    top: 12px;
    right: 12px;
    width: 28px;
    height: 28px;
    display: grid;
    place-items: center;
    font-size: 14px;
    color: var(--text-muted);
    border: none;
    background: transparent;
    border-radius: 50%;
    cursor: pointer;
    transition: color 0.2s ease;
}
.reference-info-dialog-close .codicon {
    font-size:18px
}

.reference-info-row {
    display: flex;
    gap: 8px;
    padding: 2px 0;
    font-size: 14px;
    line-height: 1.6;
}
.reference-info-row:last-child {
    border-bottom: none;
}
.reference-info-key {
    flex-shrink: 0;
    min-width: 80px;
    font-weight: 600;
    color: var(--text-muted);
    font-family: system-ui, -apple-system, sans-serif;
    font-size: 12.5px;
}
.reference-info-value {
    flex: 1;
    color: var(--text-color);
}

@keyframes ref-dialog-in {
    from { opacity: 0; transform: scale(0.95); }
    to   { opacity: 1; transform: scale(1); }
}

/* ── theorem sub-list ──────────────────────── */

.reference-theorems {
    padding: 2px 6px 16px 46px;
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.theorem-link {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 9px 12px;
    border-radius: 8px;
    background: transparent;
    color: var(--text-color);
    text-decoration: none;
    transition: background 0.2s ease;
}
.theorem-link:hover {
    background: var(--reference-theorem-hover);
}
.theorem-link-unresolved {
    cursor: default;
}
.theorem-link-unresolved:hover {
    background: transparent;
}
.theorem-name {
    font-family: 'Consolas', monospace;
    font-size: 13px;
    font-weight: 400;
    color: var(--text-color);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}
.theorem-location {
    margin-left: auto;
    font-family: 'Consolas', monospace;
    font-size: 12px;
    color: var(--text-muted);
    white-space: nowrap;
    flex-shrink: 0;
}
.theorem-go {
    flex-shrink: 0;
    width: 28px;
    height: 28px;
    display: grid;
    place-items: center;
    color: var(--reference-accent);
    opacity: 0;
    transform: translateX(-4px);
    transition: opacity 0.2s ease, transform 0.2s ease;
}
.theorem-go .codicon {
    font-size:18px
}
.theorem-link:hover .theorem-go {
    opacity: 1;
    transform: translateX(0);
}

@media (prefers-reduced-motion: reduce) {
    html {
        scroll-behavior: auto;
    }
}