/* GRADI Blog — Shared Styles (listing + articles) */
:root {
  --bg-primary: #F8F9FA;
  --bg-surface: #FFFFFF;
  --accent: #4361EE;
  --accent-light: #5B7BF5;
  --accent-glow: rgba(67, 97, 238, 0.06);
  --accent-subtle: rgba(67, 97, 238, 0.1);
  --text-primary: #1A1A2E;
  --text-secondary: #4A4A5A;
  --text-muted: #5A6370;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-display: 'Cormorant Garamond', Georgia, serif;
  --color-border: #E0E0E0;
  --duration-fast: 0.3s;
  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 1.5rem;
  --space-lg: 2rem;
  --space-xl: 3rem;
  --radius-sm: 8px;
  --radius-md: 12px;
  --cat-pedagogy: #2DC653;
  --cat-research: #7B61FF;
  --cat-curriculum: #F59E0B;
  --cat-society: #4361EE;
  --cat-parents: #E67E22;
}

*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-font-smoothing: antialiased; -webkit-tap-highlight-color: transparent; }
img { max-width: 100%; height: auto; display: block; }

body {
  font-family: var(--font-body);
  background: var(--bg-primary);
  color: var(--text-primary);
  min-height: 100vh;
  line-height: 1.7;
}

/* ── Header ── */
.header {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: calc(56px + env(safe-area-inset-top, 0px));
  padding-top: env(safe-area-inset-top, 0px);
  background: var(--bg-primary);
  border-bottom: 1px solid var(--color-border);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
}

.back-btn {
  position: absolute;
  left: 0;
  background: none;
  border: none;
  color: var(--text-muted);
  font-size: 1.5rem;
  cursor: pointer;
  min-width: 56px;
  min-height: 56px;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0 0 0 0.75rem;
  transition: color var(--duration-fast);
}
.back-btn:hover { color: var(--text-primary); }

.header-share {
  position: absolute;
  right: 0.5rem;
  background: none;
  border: none;
  color: var(--text-muted);
  font-size: 1.2rem;
  cursor: pointer;
  min-width: 44px;
  min-height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: color var(--duration-fast);
}
@media (hover: hover) { .header-share:hover { color: var(--accent); } }

.header-title {
  font-size: 1.1rem;
  font-weight: 600;
}
.beta-tag {
  font-size: 0.5rem;
  font-weight: 700;
  background: #4361EE;
  color: #FFF;
  padding: 0.1rem 0.3rem;
  border-radius: 3px;
  letter-spacing: 0.06em;
  margin-left: 6px;
}

/* ── Main ── */
.main {
  padding: calc(80px + env(safe-area-inset-top, 0px)) var(--space-lg) calc(var(--space-xl) + env(safe-area-inset-bottom, 0px));
  max-width: 700px;
  margin: 0 auto;
}

/* ── Hero (listing page) ── */
.hero {
  text-align: center;
  margin-bottom: var(--space-xl);
}

.hero-badge {
  display: inline-block;
  background: var(--accent);
  color: #fff;
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  padding: 0.35rem 0.75rem;
  border-radius: 100px;
  margin-bottom: var(--space-md);
}

.hero-title {
  font-family: var(--font-display);
  font-size: clamp(1.75rem, 6vw, 2.25rem);
  font-weight: 700;
  margin-bottom: var(--space-sm);
  line-height: 1.2;
}

.hero-subtitle {
  font-size: 1rem;
  color: var(--text-muted);
  max-width: 520px;
  margin: 0 auto;
}

/* ── Podcast Capsule ── */
.podcast-capsule {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.35rem 0.9rem;
  background: rgba(67, 97, 238, 0.08);
  border: 1px solid rgba(67, 97, 238, 0.18);
  border-radius: 100px;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--accent);
  text-decoration: none;
  transition: all var(--duration-fast);
}
.podcast-capsule:hover {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
  transform: translateY(-1px);
}

/* ── Category Filters ── */
.category-filters {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.5rem;
  margin-bottom: var(--space-lg);
}
@media (min-width: 480px) {
  .category-filters { grid-template-columns: repeat(6, 1fr); }
}

.filter-btn {
  padding: 0.5rem 0.4rem;
  border: 1px solid var(--color-border);
  border-radius: 100px;
  background: var(--bg-surface);
  color: var(--text-muted);
  font-family: var(--font-body);
  font-size: 0.8rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--duration-fast);
  text-align: center;
  white-space: nowrap;
}

.filter-btn:hover { border-color: var(--accent); color: var(--accent); }

.filter-btn.active {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

/* ── Category Tags ── */
.category-tag {
  display: inline-block;
  font-size: 0.65rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 0.2rem 0.55rem;
  border-radius: 4px;
  color: #fff;
}

.category-pedagogy { background: var(--cat-pedagogy); }
.category-research { background: var(--cat-research); }
.category-curriculum { background: var(--cat-curriculum); }
.category-society { background: var(--cat-society); }
.category-parents { background: var(--cat-parents); }

/* ── Article Cards (listing) ── */
.article-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.article-card {
  display: block;
  background: var(--bg-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
  text-decoration: none;
  color: inherit;
  max-width: 100%;
  transition: transform var(--duration-fast), box-shadow var(--duration-fast);
}

.article-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.08);
}

.article-card-image {
  width: 100%;
  max-width: 100%;
  height: 140px;
  object-fit: cover;
  display: block;
}

@media (min-width: 480px) {
  .article-card-image { height: 160px; }
}

.article-card-body {
  padding: var(--space-md) var(--space-lg);
}

.article-card-meta {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  margin-bottom: 0.6rem;
}

.article-card-ep {
  font-size: 0.7rem;
  font-weight: 700;
  color: var(--accent);
  letter-spacing: 0.02em;
}

.article-card-date {
  font-size: 0.75rem;
  color: var(--text-muted);
}

.article-card-title {
  font-family: var(--font-display);
  font-size: 1.2rem;
  font-weight: 700;
  line-height: 1.3;
  margin-bottom: 0.4rem;
}

.article-card-excerpt {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 0.6rem;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.article-card-read {
  font-size: 0.72rem;
  color: var(--text-muted);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

/* ── Article Hero Image ── */
.article-hero-wrap {
  position: relative;
  margin-bottom: var(--space-lg);
  border-radius: var(--radius-md);
  overflow: hidden;
}
.article-hero-image {
  width: 100%;
  height: 240px;
  object-fit: cover;
  border-radius: var(--radius-md);
  display: block;
}
.article-hero-wrap .article-hero-image {
  margin-bottom: 0;
}
.article-hero-badge {
  position: absolute;
  bottom: 8px;
  padding: 0.2rem 0.6rem;
  border-radius: 100px;
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: #fff;
  text-decoration: none;
  z-index: 2;
}
.article-hero-badge--brand {
  right: 8px;
  background: var(--accent);
}
.article-hero-badge--ep {
  left: 8px;
  background: var(--accent);
}
@media (min-width: 600px) {
  .article-hero-image { height: 320px; }
}

/* ── Article Page ── */
.article-meta {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: var(--space-md);
  flex-wrap: wrap;
}

.article-date {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.article-reading-time {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.article-reading-time::before {
  content: "\00B7";
  margin-right: 0.75rem;
}

.article-title {
  font-family: var(--font-display);
  font-size: clamp(1.6rem, 5vw, 2.2rem);
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: var(--space-sm);
}

.article-listen-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.7rem 1.5rem;
  background: var(--accent);
  color: #fff;
  border-radius: 100px;
  font-family: var(--font-body);
  font-size: 0.9rem;
  font-weight: 600;
  text-decoration: none;
  margin-bottom: var(--space-md);
  transition: all var(--duration-fast);
}
.article-listen-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(67, 97, 238, 0.3);
}
.article-listen-btn svg {
  flex-shrink: 0;
}

.article-lead {
  font-size: 1.05rem;
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: var(--space-xl);
  font-style: italic;
}

.article-section {
  margin-bottom: var(--space-lg);
}

.article-section h2 {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: var(--space-sm);
  padding-top: var(--space-sm);
  border-top: 1px solid var(--color-border);
}

.article-section:first-of-type h2 {
  border-top: none;
  padding-top: 0;
}

.article-section p {
  font-size: 0.92rem;
  color: var(--text-secondary);
  line-height: 1.85;
  margin-bottom: var(--space-sm);
}

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

.article-section blockquote {
  border-left: 3px solid var(--accent);
  padding: var(--space-sm) var(--space-md);
  margin: var(--space-md) 0;
  background: var(--accent-glow);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  font-style: italic;
  color: var(--text-secondary);
  font-size: 0.92rem;
  line-height: 1.7;
}

.article-section ul {
  list-style: none;
  padding: 0 0 0 0.75rem;
  margin: var(--space-sm) 0;
}

.article-section ul li {
  position: relative;
  padding-left: 1.4rem;
  font-size: 0.92rem;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 0.5rem;
}

.article-section ul li::before {
  content: "\2022";
  position: absolute;
  left: 0;
  color: var(--accent);
  font-weight: 700;
}

.article-section strong {
  color: var(--text-primary);
  font-weight: 600;
}

/* ── Article Attribution ── */
.article-attribution {
  margin-top: var(--space-xl);
  padding: var(--space-md) var(--space-lg);
  background: var(--accent-glow);
  border-radius: var(--radius-md);
  text-align: center;
}
.article-attribution p {
  font-size: 0.82rem;
  font-style: italic;
  color: var(--text-secondary);
  line-height: 1.7;
  max-width: 520px;
  margin: 0 auto;
}

/* ── Article Footer ── */
.article-footer {
  margin-top: var(--space-xl);
  padding-top: var(--space-lg);
  border-top: 1px solid var(--color-border);
  text-align: center;
}

.back-to-blog {
  display: inline-block;
  padding: 0.75rem 1.5rem;
  background: var(--accent);
  color: #fff;
  border-radius: 100px;
  font-size: 0.88rem;
  font-weight: 600;
  text-decoration: none;
  transition: all var(--duration-fast);
}

.back-to-blog:hover {
  background: var(--accent-light);
  transform: scale(1.02);
}

/* ── Site Footer (shared across all content pages) ── */
.site-footer {
  text-align: center;
  padding: var(--space-lg);
}

.site-footer p {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-muted);
  margin-bottom: 0.25rem;
}

.site-footer a {
  font-size: 0.8rem;
  color: var(--accent);
  text-decoration: none;
  font-weight: 500;
}

.site-footer a:hover {
  opacity: 0.8;
}

/* ── Empty state ── */
.empty-state {
  text-align: center;
  padding: var(--space-xl) var(--space-md);
  color: var(--text-muted);
}

.empty-state-icon { font-size: 3rem; margin-bottom: var(--space-sm); }
.empty-state-text { font-size: 0.9rem; }