/* ============================================
   ARTICLES PAGE — articles/index.html
   ============================================ */

/* ---- Page header --------------------------- */
.articles-header {
  padding: var(--section-padding) 0 var(--space-16);
  border-bottom: 1px solid var(--color-border);
}

.articles-header__eyebrow {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 400;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-bottom: var(--space-3);
}

.articles-header__title {
  font-family: var(--font-display);
  font-size: clamp(var(--text-4xl), 6vw, var(--text-6xl));
  font-weight: 300;
  line-height: 1.05;
  letter-spacing: -0.03em;
  color: var(--color-text);
  margin-bottom: var(--space-6);
}

.articles-header__sub {
  font-size: var(--text-lg);
  color: var(--color-text-muted);
  max-width: 600px;
  line-height: 1.7;
}

/* ---- Filter tabs — flat, mono, no pills ---- */
.articles-filters {
  padding: var(--space-6) 0;
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: var(--nav-height);
  background: var(--color-bg);
  z-index: 10;
}

.filter-tabs {
  display: flex;
  gap: var(--space-1);
  flex-wrap: wrap;
  align-items: center;
}

.filter-tab {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-4);
  border: none;
  border-radius: 0;
  background: transparent;
  color: var(--color-text-muted);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 400;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  cursor: pointer;
  transition: color var(--duration-fast);
  position: relative;
}

/* Active indicator: bottom border only */
.filter-tab::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: var(--space-4);
  right: var(--space-4);
  height: 1px;
  background-color: var(--color-text);
  transform: scaleX(0);
  transition: transform var(--duration-base) var(--ease-out);
}

.filter-tab:hover {
  color: var(--color-text);
}

.filter-tab:focus-visible {
  outline: 2px solid var(--color-highlight);
  outline-offset: 2px;
  border-radius: 2px;
}

.filter-tab.active {
  color: var(--color-text);
}

.filter-tab.active::after {
  transform: scaleX(1);
}

.filter-tab__count {
  font-size: var(--text-xs);
  opacity: 0.5;
  letter-spacing: 0;
}

/* ---- Sub-tag filter row -------------------- */
.filter-subtabs {
  display: flex;
  gap: var(--space-1);
  flex-wrap: wrap;
  margin-top: var(--space-2);
}

.filter-subtab {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-1) var(--space-3);
  border: none;
  background: transparent;
  color: var(--color-text-muted);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 400;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  cursor: pointer;
  transition: color var(--duration-fast);
  position: relative;
}

.filter-subtab::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: var(--space-3);
  right: var(--space-3);
  height: 1px;
  background-color: var(--color-text-muted);
  transform: scaleX(0);
  transition: transform var(--duration-base) var(--ease-out);
}

.filter-subtab:hover {
  color: var(--color-text);
}

.filter-subtab:focus-visible {
  outline: 2px solid var(--color-highlight);
  outline-offset: 2px;
  border-radius: 2px;
}

.filter-subtab.active {
  color: var(--color-text);
}

.filter-subtab.active::after {
  transform: scaleX(1);
}

/* ---- Post list ----------------------------- */
.articles-grid {
  padding: var(--space-12) 0 var(--section-padding);
}

.post-grid {
  display: flex;
  flex-direction: column;
  gap: 0;
}

/* ---- Post card — typographic list item ----- */
.post-card {
  background: transparent;
  border: none;
  border-bottom: 1px solid var(--color-border);
  border-radius: 0;
  overflow: visible;
  transition: none;
}

.post-card:first-child {
  border-top: 1px solid var(--color-border);
}

.post-card__link {
  display: block;
  text-decoration: none;
  color: inherit;
  padding: var(--space-7) 0;
  transition: none;
}

.post-card__link:focus-visible {
  outline: 2px solid var(--color-highlight);
  outline-offset: 4px;
  border-radius: 2px;
}

.post-card__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-6);
  min-height: auto;
  padding: 0;
}

.post-card__meta {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  flex-shrink: 0;
  order: 2;
}

.post-card__pillar {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 400;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  /* override tag styles */
  background: transparent;
  border: none;
  padding: 0;
  border-radius: 0;
}

.post-card__date {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  letter-spacing: 0.03em;
}

.post-card__title {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  font-weight: 500;
  line-height: 1.3;
  letter-spacing: -0.01em;
  color: var(--color-text);
  transition: color var(--duration-fast);
  flex: 1;
  order: 1;
  margin-bottom: 0;
}

.post-card:hover .post-card__title {
  color: var(--color-accent);
}

.post-card__excerpt {
  display: none; /* hide excerpts — typographic list doesn't need them */
}

.post-card__footer {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  order: 3;
  margin-top: 0;
  flex-shrink: 0;
}

.post-card__read-time {
  display: none; /* clean list — remove read time */
}

.post-card__arrow {
  color: var(--color-text-muted);
  font-size: var(--text-base);
  transition: transform var(--duration-base) var(--ease-out),
              color var(--duration-fast);
}

.post-card:hover .post-card__arrow {
  transform: translateX(4px);
  color: var(--color-text);
}

/* Empty state */
.articles-empty {
  text-align: center;
  color: var(--color-text-muted);
  padding: var(--space-16) 0;
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  letter-spacing: 0.05em;
}

/* ---- Responsive ---------------------------- */
@media (max-width: 768px) {
  .articles-header {
    padding: var(--space-20) 0 var(--space-10);
  }

  .post-card__inner {
    flex-wrap: wrap;
    gap: var(--space-2);
  }

  .post-card__title {
    font-size: var(--text-lg);
    flex-basis: 100%;
    order: 1;
  }

  .post-card__meta {
    order: 2;
    flex-basis: auto;
  }

  .post-card__footer {
    order: 3;
    margin-left: auto;
  }

  .filter-tabs {
    gap: var(--space-1);
  }

  .filter-tab {
    font-size: 0.65rem;
    padding: var(--space-2) var(--space-3);
  }
}