/* ─── Research Directions page ─── */

.research-header {
    padding: var(--space-8) 0 var(--space-12);
}

.research-header h1 {
    margin-bottom: var(--space-3);
}

.research-description {
    font-size: var(--text-lg);
    color: var(--color-text-secondary);
    margin-bottom: 0;
}

/* ─── Table of contents (directions overview) ─── */
.directions-toc-block {
    margin-bottom: var(--space-12);
}

.directions-toc-block .section-label {
    margin-bottom: var(--space-4);
}

.directions-toc {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    flex-direction: column;
    gap: var(--space-3);
}

.accordion-item { margin: 0; }

.toc-item {
    display: flex;
    align-items: flex-start;
    gap: 1.25rem;
    padding: 1.25rem 2rem;
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    text-decoration: none;
    color: var(--color-text);
    transition: border-color 0.25s, background 0.25s, border-radius 0.15s;
    font: inherit;
    cursor: pointer;
    width: 100%;
    text-align: left;
    -webkit-appearance: none;
    appearance: none;
}

.toc-item:hover {
    border-color: var(--color-accent);
    background: var(--color-bg-card);
    text-decoration: none;
    color: var(--color-text);
}

.toc-num {
    font-family: var(--font-mono);
    font-size: var(--text-sm);
    color: var(--color-text-muted);
    letter-spacing: 0.04em;
    flex-shrink: 0;
    padding-top: 2px;
}

.toc-item:hover .toc-num {
    color: var(--color-accent);
}

.toc-text {
    flex: 1;
    min-width: 0;
    display: flex;
    flex-direction: column;
    gap: var(--space-1);
}

.toc-title {
    display: block;
    font-family: var(--font-heading);
    font-size: var(--text-lg);
    font-weight: 600;
    color: var(--color-text);
    line-height: 1.3;
}

.toc-tagline {
    display: block;
    font-family: var(--font-heading);
    font-style: italic;
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
    line-height: 1.55;
}

.toc-arrow {
    flex-shrink: 0;
    font-family: var(--font-mono);
    color: var(--color-text-muted);
    font-size: var(--text-base);
    line-height: 1;
    padding-top: 4px;
    transition: color 0.2s, transform 0.3s ease;
}

.toc-item:hover .toc-arrow {
    color: var(--color-accent);
}

/* ─── Accordion expand/collapse ─── */

.accordion-header[aria-expanded="true"] {
    border-color: var(--color-accent);
    border-bottom-left-radius: 0;
    border-bottom-right-radius: 0;
    background: var(--color-accent-light);
}

.accordion-header[aria-expanded="true"]:hover {
    border-color: var(--color-accent);
}

.accordion-header[aria-expanded="true"] .toc-arrow {
    transform: rotate(90deg);
    color: var(--color-accent);
}

.accordion-header:focus-visible {
    outline: 2px solid var(--color-accent);
    outline-offset: 2px;
}

.accordion-body {
    display: none;
    border: 1px solid var(--color-accent);
    border-top: none;
    border-radius: 0 0 var(--border-radius) var(--border-radius);
    padding: 0 var(--space-8) var(--space-4);
}

.accordion-body.open {
    display: block;
    animation: accordionFadeIn 0.3s ease-out;
}

@keyframes accordionFadeIn {
    from { opacity: 0; transform: translateY(-8px); }
    to   { opacity: 1; transform: translateY(0); }
}

.accordion-body .direction-panel {
    padding: var(--space-6) 0 0;
    margin-bottom: 0;
    border-bottom: none;
    animation: none;
}

.accordion-body .direction-header {
    margin-bottom: var(--space-8);
}

/* ─── Stacked direction sections ─── */
.directions-stack {
    display: flex;
    flex-direction: column;
}

.direction-panel {
    animation: fadeIn 0.25s ease;
    padding-bottom: var(--space-20);
    margin-bottom: var(--space-20);
    border-bottom: 1px solid var(--color-rule);
    scroll-margin-top: var(--space-8);
}

.direction-panel:last-child {
    margin-bottom: 0;
    padding-bottom: 0;
    border-bottom: none;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(4px); }
    to   { opacity: 1; transform: translateY(0); }
}

/* ─── Direction header ─── */
.direction-header {
    margin-bottom: var(--space-12);
    padding-bottom: var(--space-8);
    border-bottom: 1px solid var(--color-border-light);
}

.direction-eyebrow {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    margin-bottom: var(--space-4);
}

.direction-eyebrow-divider {
    color: var(--color-text-muted);
    opacity: 0.6;
}

.direction-eyebrow-index {
    color: var(--color-text-secondary);
}

.direction-title {
    font-family: var(--font-heading);
    font-size: var(--text-4xl);
    font-weight: 600;
    color: var(--color-text);
    letter-spacing: -0.02em;
    line-height: 1.15;
    margin-bottom: var(--space-4);
}

.direction-tagline {
    font-family: var(--font-heading);
    font-style: italic;
    font-size: var(--text-xl);
    color: var(--color-text-secondary);
    line-height: 1.5;
    margin-bottom: 0;
    max-width: 640px;
}

/* ─── Direction sections (overview / themes / featured) ─── */
.direction-section {
    margin-bottom: var(--space-12);
}

.direction-section:last-child {
    margin-bottom: 0;
}

.direction-section .section-label {
    margin-bottom: var(--space-4);
}

.direction-desc {
    font-family: var(--font-body);
    font-size: var(--text-base);
    line-height: 1.8;
    color: var(--color-text);
    max-width: var(--content-width);
    margin-bottom: 0;
}

/* ─── Themes ─── */
.themes-list {
    list-style: none;
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-2);
    padding: 0;
    margin: 0;
}

.theme-pill {
    display: inline-block;
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    letter-spacing: 0.02em;
    padding: 6px 14px;
    border: 1px solid var(--color-border);
    border-radius: 100px;
    background: var(--color-bg-alt);
    color: var(--color-text-secondary);
    transition: border-color 0.2s, color 0.2s;
}

.theme-pill:hover {
    border-color: var(--color-accent);
    color: var(--color-accent);
}

/* ─── Featured papers ─── */
.featured-papers {
    display: flex;
    flex-direction: column;
    gap: var(--space-4);
}

.featured-paper-card {
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    padding: var(--space-6);
    transition: border-color 0.25s;
}

.featured-paper-card:hover {
    border-color: var(--color-text-muted);
}

.featured-paper-head {
    display: flex;
    align-items: baseline;
    gap: var(--space-3);
    margin-bottom: var(--space-3);
    flex-wrap: wrap;
}

.featured-venue {
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    color: var(--color-text-muted);
    flex: 1 1 auto;
    min-width: 0;
}

.featured-date {
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    color: var(--color-text-muted);
    white-space: nowrap;
    flex-shrink: 0;
}

a.featured-paper-title,
span.featured-paper-title {
    display: block;
    font-family: var(--font-heading);
    font-size: var(--text-lg);
    font-weight: 600;
    color: var(--color-text);
    text-decoration: none;
    line-height: 1.4;
    margin-bottom: var(--space-3);
}

a.featured-paper-title:hover {
    color: var(--color-accent);
    text-decoration: none;
}

.featured-authors {
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
    line-height: 1.6;
    margin-bottom: var(--space-4);
}

.featured-summary {
    font-size: var(--text-sm);
    line-height: 1.75;
    color: var(--color-text);
    padding: var(--space-4);
    border-left: 2px solid var(--color-rule);
    margin-bottom: var(--space-4);
    background: var(--color-bg-alt);
    border-radius: 0 var(--border-radius) var(--border-radius) 0;
}

.featured-links {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    flex-wrap: wrap;
}

/* ─── Responsive ─── */
@media (max-width: 600px) {
    .toc-item {
        padding: 1rem 1.25rem;
        gap: var(--space-3);
    }

    .toc-title {
        font-size: var(--text-base);
    }

    .direction-title {
        font-size: var(--text-3xl);
    }

    .direction-tagline {
        font-size: var(--text-lg);
    }

    .featured-paper-card {
        padding: var(--space-4);
    }

    .accordion-body {
        padding: 0 var(--space-4) var(--space-4);
    }
}