/* =========================================
   READING PROGRESS BAR
   ========================================= */
.blog-progress-bar {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  width: 0%;
  background: var(--color-primary);
  z-index: 9999;
  transition: width 0.1s linear;
  border-radius: 0 2px 2px 0;
}

/* =========================================
   BLOG PAGE LAYOUT
   ========================================= */
.blog-wrapper {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 52px var(--container-padding-desktop) 100px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) 300px;
  gap: 56px;
  align-items: start;
}

.blog-container {
  min-width: 0;
}

/* =========================================
   ARTICLE HEADER
   ========================================= */
.blog-category {
  display: inline-block;
  font-family: var(--font-body);
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-primary);
  background: rgba(103, 158, 245, 0.1);
  border: 1px solid rgba(103, 158, 245, 0.25);
  padding: 5px 14px;
  border-radius: var(--radius-rounded);
  margin-bottom: 20px;
}

.blog-container h1 {
  font-family: var(--font-heading);
  font-size: clamp(1.75rem, 3.5vw, 2.5rem);
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -0.025em;
  color: var(--text-primary);
  margin: 0 0 24px;
}

/* =========================================
   BLOG META — author / date / read time
   ========================================= */
.blog-meta {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 32px;
  font-family: var(--font-body);
  font-size: 0.875rem;
  color: var(--text-secondary);
}

.blog-author {
  display: flex;
  align-items: center;
  gap: 10px;
}

.blog-author-avatar {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-heading);
  font-size: 0.7rem;
  font-weight: 800;
  letter-spacing: 0.02em;
  color: var(--color-white);
  flex-shrink: 0;
}

/* ─── Author variants ─── */
.avatar--team    { background: var(--color-primary); }   /* Learntit Team   — blue    */
.avatar--maths   { background: #6C5CE7; }               /* Maths Team      — indigo  */
.avatar--science { background: #00B894; }               /* Science Team    — emerald */

.blog-author-name {
  font-weight: 600;
  color: var(--text-primary);
}

.blog-meta-dot {
  width: 3px;
  height: 3px;
  border-radius: 50%;
  background: var(--color-border);
  flex-shrink: 0;
}

.blog-date,
.blog-read-time {
  color: var(--text-secondary);
}

/* =========================================
   HERO IMAGE
   ========================================= */
.blog-feature-wrapper {
  margin: 0 0 40px;
  border-radius: var(--radius-primary);
  overflow: hidden;
}

.blog-feature-image {
  width: 100%;
  display: block;
  aspect-ratio: 16 / 9;
  object-fit: cover;
}

/* =========================================
   BLOG CONTENT TYPOGRAPHY
   ========================================= */
.blog-content {
  font-family: var(--font-body);
  font-size: 1.0625rem;
  line-height: 1.78;
  color: var(--text-primary);
}

.blog-content > p:first-child {
  font-size: 1.125rem;
  font-weight: 500;
  color: var(--text-primary);
  line-height: 1.7;
}

.blog-content p {
  margin: 0 0 1.4em;
}

.blog-content h2 {
  font-family: var(--font-heading);
  font-size: 1.45rem;
  font-weight: 700;
  line-height: 1.25;
  letter-spacing: -0.015em;
  color: var(--text-primary);
  margin: 2.6em 0 0.8em;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--color-border);
}

.blog-content h3 {
  font-family: var(--font-heading);
  font-size: 1.15rem;
  font-weight: 700;
  line-height: 1.35;
  color: var(--text-primary);
  margin: 2em 0 0.6em;
}

.blog-content ul,
.blog-content ol {
  padding-left: 0;
  margin: 0 0 1.5em;
  list-style: none;
}

.blog-content ul li,
.blog-content ol li {
  position: relative;
  padding-left: 1.75em;
  margin-bottom: 0.65em;
  font-size: 1rem;
  line-height: 1.65;
}

.blog-content ul li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0.56em;
  width: 7px;
  height: 7px;
  background: var(--color-primary);
  border-radius: 50%;
}

.blog-content ol {
  counter-reset: list-counter;
}

.blog-content ol li {
  counter-increment: list-counter;
}

.blog-content ol li::before {
  content: counter(list-counter);
  position: absolute;
  left: 0;
  top: 0.08em;
  width: 22px;
  height: 22px;
  background: var(--color-primary);
  color: var(--color-white);
  font-family: var(--font-heading);
  font-size: 0.7rem;
  font-weight: 800;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
}

.blog-content blockquote {
  margin: 1.8em 0;
  padding: 20px 24px;
  border-left: 4px solid var(--color-primary);
  background: rgba(103, 158, 245, 0.05);
  border-radius: 0 var(--radius-secondary) var(--radius-secondary) 0;
}

.blog-content blockquote p {
  font-family: var(--font-heading);
  font-size: 1.08rem;
  font-weight: 600;
  font-style: italic;
  color: var(--text-primary);
  margin: 0;
  line-height: 1.6;
}

/* =========================================
   COMPONENTS
   ========================================= */

/* Callout box */
.blog-callout {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  background: rgba(103, 158, 245, 0.07);
  border: 1px solid rgba(103, 158, 245, 0.22);
  border-radius: var(--radius-secondary);
  padding: 18px 20px;
  margin: 1.8em 0;
}

.blog-callout-icon {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: var(--color-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-white);
  font-size: 0.85rem;
  flex-shrink: 0;
  margin-top: 1px;
}

.blog-callout-body strong {
  display: block;
  font-family: var(--font-heading);
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 5px;
}

.blog-callout-body p {
  font-family: var(--font-body);
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin: 0;
  line-height: 1.6;
}

/* Stats row */
.blog-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin: 2em 0;
}

.blog-stat {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-secondary);
  padding: 22px 16px;
  gap: 6px;
}

.blog-stat-number {
  font-family: var(--font-heading);
  font-size: 1.9rem;
  font-weight: 800;
  color: var(--color-primary);
  line-height: 1;
}

.blog-stat-label {
  font-family: var(--font-body);
  font-size: 0.8rem;
  color: var(--text-secondary);
  line-height: 1.4;
}

/* Mid-post CTA banner */
.blog-cta-banner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  background: var(--color-primary);
  border-radius: var(--radius-primary);
  padding: 26px 28px;
  margin: 2.4em 0;
}

.blog-cta-banner-copy strong {
  display: block;
  font-family: var(--font-heading);
  font-size: 1rem;
  font-weight: 700;
  color: var(--color-white);
  margin-bottom: 5px;
}

.blog-cta-banner-copy p {
  font-family: var(--font-body);
  font-size: 0.875rem;
  color: rgba(255, 255, 255, 0.85);
  margin: 0;
  line-height: 1.5;
}

.blog-cta-banner a {
  white-space: nowrap;
  font-family: var(--font-body);
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--color-primary);
  background: var(--color-white);
  padding: 11px 22px;
  border-radius: var(--radius-rounded);
  text-decoration: none;
  flex-shrink: 0;
  transition: opacity var(--transition-fast);
}

.blog-cta-banner a:hover {
  opacity: 0.9;
}

/* =========================================
   RELATED POSTS
   ========================================= */
.blog-related {
  margin-top: 72px;
  padding-top: 40px;
  border-top: 1px solid var(--color-border);
}

.blog-related-title {
  font-family: var(--font-heading);
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text-primary);
  margin: 0 0 24px;
}

.blog-related-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}

.blog-related-card {
  text-decoration: none;
  color: inherit;
  display: flex;
  flex-direction: column;
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-secondary);
  overflow: hidden;
  transition: transform var(--transition-medium), box-shadow var(--transition-medium), border-color var(--transition-medium);
}

.blog-related-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.07);
  border-color: transparent;
}

.blog-related-card-img {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  display: block;
}

.blog-related-card-body {
  padding: 14px 16px 18px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  flex: 1;
}

.blog-related-card-body h4 {
  font-family: var(--font-heading);
  font-size: 0.875rem;
  font-weight: 700;
  line-height: 1.45;
  color: var(--text-primary);
  margin: 0;
}

.blog-related-card-body span {
  font-family: var(--font-body);
  font-size: 0.75rem;
  color: var(--text-secondary);
  margin-top: auto;
}

/* =========================================
   SIDEBAR
   ========================================= */
.blog-aside {
  position: sticky;
  top: 96px;
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.ad-sticky {
  border-radius: var(--radius-primary);
  overflow: hidden;
  border: 1px solid var(--color-border);
  /* ─── Fallback poster (replace with real ad when Google approves) ─── */
  background-color: var(--color-primary);
  background-image: url(/images/blog-ad-fallback.png);
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
}

.ad-label {
  font-family: var(--font-body);
  font-size: 0.68rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-secondary);
  text-align: center;
  padding: 8px 0 6px;
  background-color: var(--color-white);
  border-bottom: 1px solid var(--color-border);
}

.ad-box {
  width: 300px;
  height: 600px;
  display: block;
  margin: 0 auto;
}

/* Sidebar nudge */
.sidebar-nudge {
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-primary);
  padding: 24px 20px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.sidebar-nudge-title {
  font-family: var(--font-heading);
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-primary);
  margin: 0;
}

.sidebar-nudge-text {
  font-family: var(--font-body);
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.55;
  margin: 0;
}

.sidebar-nudge a {
  display: block;
  font-family: var(--font-body);
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--color-white);
  background: var(--color-primary);
  padding: 11px 18px;
  border-radius: var(--radius-rounded);
  text-decoration: none;
  text-align: center;
  margin-top: 4px;
  transition: opacity var(--transition-fast);
}

.sidebar-nudge a:hover {
  opacity: 0.85;
}

/* =========================================
   RESPONSIVE
   ========================================= */
@media (max-width: 1100px) {
  .blog-wrapper {
    grid-template-columns: minmax(0, 1fr) 260px;
    gap: 40px;
  }
}

@media (max-width: 900px) {
  .blog-wrapper {
    grid-template-columns: 1fr;
    padding: 36px var(--container-padding-tablet) 72px;
    gap: 0;
  }

  .blog-aside {
    position: static;
    margin-top: 56px;
  }

  .ad-sticky {
    display: none;
  }

  .blog-related-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 640px) {
  .blog-wrapper {
    padding: 28px var(--container-padding-mobile) 56px;
  }

  .blog-content h2 {
    font-size: 1.25rem;
  }

  .blog-stats {
    grid-template-columns: 1fr;
  }

  .blog-cta-banner {
    flex-direction: column;
    text-align: center;
  }

  .blog-cta-banner a {
    width: 100%;
    text-align: center;
  }

  .blog-related-grid {
    grid-template-columns: 1fr;
  }
}