/* ============================================================
   POLICY PAPERS LIBRARY — Supplementary styles
   Inherits from styles.css (base tokens, nav, footer)
   ============================================================ */

/* ── Page header ──────────────────────────────────────────── */
.papers-header {
    padding: calc(48px + 64px) 80px 48px;
    border-bottom: 1px solid var(--border);
    background: var(--notion-bg);
}

.papers-header-inner {
    max-width: var(--max-width);
    margin: 0 auto;
    display: grid;
    grid-template-columns: 1fr auto;
    gap: var(--space-lg);
    align-items: end;
}

.papers-kicker {
    font-size: 0.7rem;
    font-weight: 400;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    color: var(--text-muted);
    margin-bottom: 12px;
}

.papers-title {
    font-family: var(--font-display);
    font-size: clamp(3rem, 8vw, 6rem);
    font-weight: 400;
    letter-spacing: 0.02em;
    line-height: 0.92;
    color: var(--black);
    margin-bottom: var(--space-md);
}

.papers-subtitle {
    font-size: 0.95rem;
    color: var(--text-secondary);
    line-height: 1.65;
    max-width: 540px;
}

.papers-header-meta {
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
    align-items: flex-end;
    flex-shrink: 0;
}

.meta-stat {
    text-align: right;
}

.meta-number {
    display: block;
    font-family: var(--font-display);
    font-size: 1.8rem;
    font-weight: 400;
    color: var(--black);
    letter-spacing: 0.02em;
    line-height: 1;
}

.meta-label {
    font-size: 0.65rem;
    font-weight: 500;
    letter-spacing: 0.14em;
    text-transform: uppercase;
    color: var(--text-muted);
}

/* ── Controls ──────────────────────────────────────────────── */
.papers-controls-wrap {
    position: sticky;
    top: 48px;
    z-index: 50;
    background: rgba(255,255,255,0.96);
    border-bottom: 1px solid var(--border);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
}

.papers-controls {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 16px 80px 0;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.papers-search-wrap {
    position: relative;
    display: flex;
    align-items: center;
}

.search-icon {
    position: absolute;
    left: 12px;
    color: var(--text-muted);
    pointer-events: none;
    flex-shrink: 0;
}

#papers-search {
    width: 100%;
    max-width: 420px;
    height: 38px;
    padding: 0 12px 0 36px;
    font-family: var(--font-body);
    font-size: 0.9rem;
    color: var(--text-default);
    background: var(--notion-warm);
    border: 1px solid var(--border);
    border-radius: 4px;
    outline: none;
    transition: border-color 0.18s ease, box-shadow 0.18s ease;
}

#papers-search::placeholder { color: var(--text-muted); }

#papers-search:focus {
    border-color: var(--brand-mid);
    box-shadow: 0 0 0 3px rgba(37, 68, 66, 0.08);
    background: var(--white);
}

/* Filter chips */
.papers-filters {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    padding-bottom: 14px;
}

.filter-chip {
    font-family: var(--font-body);
    font-size: 0.72rem;
    font-weight: 400;
    letter-spacing: 0.02em;
    color: var(--text-secondary);
    background: transparent;
    border: 1px solid var(--border);
    border-radius: 3px;
    padding: 5px 12px;
    cursor: pointer;
    transition: background 0.15s ease, color 0.15s ease, border-color 0.15s ease;
    white-space: nowrap;
}

.filter-chip:hover {
    background: var(--notion-warm);
    border-color: var(--border-dark);
    color: var(--text-default);
}

.filter-chip.active {
    background: var(--black);
    border-color: var(--black);
    color: #ffffff;
    font-weight: 500;
}

/* Results bar */
.papers-results-bar {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 10px 80px 12px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    border-top: 1px solid var(--border);
}

.results-count {
    font-size: 0.75rem;
    color: var(--text-muted);
    font-weight: 400;
    letter-spacing: 0.04em;
}

.sort-wrap {
    display: flex;
    align-items: center;
    gap: 8px;
}

.sort-label {
    font-size: 0.72rem;
    color: var(--text-muted);
    letter-spacing: 0.06em;
    text-transform: uppercase;
}

.sort-select {
    font-family: var(--font-body);
    font-size: 0.78rem;
    color: var(--text-default);
    background: var(--white);
    border: 1px solid var(--border);
    border-radius: 3px;
    padding: 4px 8px;
    outline: none;
    cursor: pointer;
}

.sort-select:focus {
    border-color: var(--brand-mid);
}

/* ── Papers grid ────────────────────────────────────────────── */
.papers-grid-wrap {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: var(--space-lg) 80px;
}

.papers-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1px;
    background: var(--border);
    border: 1px solid var(--border);
    border-radius: 4px;
    overflow: hidden;
}

/* Loading / empty states */
.papers-loading,
.papers-empty {
    grid-column: 1 / -1;
    padding: var(--space-lg);
    font-size: 0.9rem;
    color: var(--text-muted);
    text-align: center;
}

/* ── Paper card ─────────────────────────────────────────────── */
.paper-card {
    background: var(--white);
    padding: 22px 24px;
    display: flex;
    flex-direction: column;
    gap: 10px;
    transition: background 0.15s ease;
}

.paper-card:hover {
    background: var(--notion-warm);
}

.paper-card-top {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 8px;
}

.paper-category {
    font-size: 0.62rem;
    font-weight: 600;
    letter-spacing: 0.14em;
    text-transform: uppercase;
    color: var(--brand-mid);
    background: var(--brand-tint);
    padding: 3px 8px;
    border-radius: 2px;
}

.paper-year {
    font-family: var(--font-mono);
    font-size: 0.72rem;
    color: var(--text-muted);
    flex-shrink: 0;
}

.paper-title {
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--black);
    line-height: 1.4;
    letter-spacing: -0.01em;
}

.paper-title a {
    color: inherit;
    text-decoration: none;
    transition: color 0.15s ease;
}

.paper-title a:hover {
    color: var(--brand-mid);
    text-decoration: underline;
    text-underline-offset: 2px;
}

.paper-org {
    font-size: 0.8rem;
    font-weight: 500;
    color: var(--text-secondary);
    letter-spacing: 0.01em;
}

.paper-desc {
    font-size: 0.85rem;
    line-height: 1.6;
    color: var(--text-secondary);
    flex: 1;
}

.paper-footer {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 8px;
    padding-top: 10px;
    border-top: 1px solid var(--border);
    margin-top: auto;
}

.paper-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 4px;
}

.paper-tag {
    font-size: 0.62rem;
    color: var(--text-muted);
    background: var(--notion-warm);
    border: 1px solid var(--border);
    padding: 2px 7px;
    border-radius: 2px;
    white-space: nowrap;
}

.paper-link {
    font-size: 0.75rem;
    font-weight: 500;
    color: var(--brand-dark);
    white-space: nowrap;
    flex-shrink: 0;
    text-decoration: underline;
    text-underline-offset: 2px;
    text-decoration-color: var(--border-dark);
    transition: text-decoration-color 0.15s ease, color 0.15s ease;
}

.paper-link:hover {
    color: var(--brand-mid);
    text-decoration-color: var(--brand-mid);
}

/* ── Footer note ────────────────────────────────────────────── */
.papers-footer-note {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 var(--page-x) var(--space-xl);
    border-top: 1px solid var(--border);
    padding-top: var(--space-md);
}

.papers-footer-note p {
    font-size: 0.82rem;
    color: var(--text-muted);
    line-height: 1.55;
}

/* ── Active nav link ────────────────────────────────────────── */
.nav-active {
    color: var(--black) !important;
    font-weight: 600 !important;
}

/* ── Responsive ─────────────────────────────────────────────── */
@media (max-width: 1100px) {
    .papers-header { padding-left: 48px; padding-right: 48px; }
    .papers-controls { padding-left: 48px; padding-right: 48px; }
    .papers-results-bar { padding-left: 48px; padding-right: 48px; }
    .papers-grid-wrap { padding-left: 48px; padding-right: 48px; }
    .papers-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
    .papers-header { padding-left: var(--space-md); padding-right: var(--space-md); }
    .papers-controls { padding-left: var(--space-md); padding-right: var(--space-md); }
    .papers-results-bar { padding-left: var(--space-md); padding-right: var(--space-md); }
    .papers-grid-wrap { padding-left: var(--space-md); padding-right: var(--space-md); }

    .papers-header-inner {
        grid-template-columns: 1fr;
    }

    .papers-header-meta {
        align-items: flex-start;
        flex-direction: row;
        flex-wrap: wrap;
        gap: var(--space-md);
    }

    .meta-stat {
        text-align: left;
    }

    .papers-grid {
        grid-template-columns: 1fr;
    }

    .papers-controls-wrap {
        top: 48px;
    }

    #papers-search {
        max-width: 100%;
    }
}

@media (max-width: 480px) {
    .paper-footer {
        flex-direction: column;
        align-items: flex-start;
    }
}