/* ==========================================================================
   Features Article — extends styles.css design system
   ========================================================================== */

/* --- Article Hero --- */
.article-hero {
  padding: var(--spacing-4xl) 0 var(--spacing-2xl);
  background: linear-gradient(135deg, #1D4ED8 0%, #2563EB 50%, #3B82F6 100%);
  color: #fff;
  text-align: center;
}

.article-hero__title {
  color: #fff;
  margin-bottom: var(--spacing-md);
  font-size: clamp(1.75rem, 4.5vw, 2.75rem);
}

.article-hero__tagline {
  color: rgba(255, 255, 255, 0.9);
  font-size: var(--font-size-lg);
  max-width: 720px;
  margin: 0 auto var(--spacing-xl);
  line-height: 1.6;
}

.article-hero__stats {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--spacing-md);
}

.article-hero__badge {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-xs);
  background: rgba(255, 255, 255, 0.15);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border: 1px solid rgba(255, 255, 255, 0.25);
  border-radius: 100px;
  padding: 0.5rem 1rem;
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: #fff;
  white-space: nowrap;
}

.article-hero__badge strong {
  color: #FDE68A;
}

/* --- Article Intro --- */
.article-intro {
  padding: var(--spacing-2xl) 0;
  text-align: center;
}

.article-intro__text {
  max-width: 720px;
  margin: 0 auto;
  font-size: var(--font-size-lg);
  line-height: 1.8;
  color: var(--color-text);
}

/* --- Table of Contents (sticky horizontal nav) --- */
.toc {
  position: sticky;
  top: var(--header-height);
  z-index: 50;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
  padding: var(--spacing-sm) 0;
}

.toc__inner {
  display: flex;
  gap: var(--spacing-xs);
  overflow-x: auto;
  scrollbar-width: none;
  -ms-overflow-style: none;
  padding: 0 1.5rem;
  max-width: 1200px;
  margin: 0 auto;
}

.toc__inner::-webkit-scrollbar {
  display: none;
}

.toc__link {
  display: inline-block;
  padding: 0.375rem 0.75rem;
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--color-text-secondary);
  border-radius: 100px;
  white-space: nowrap;
  transition: background-color 0.2s, color 0.2s;
}

.toc__link:hover {
  background-color: var(--color-bg-alt);
  color: var(--color-text);
}

.toc__link--active {
  background-color: var(--color-primary);
  color: #fff;
}

.toc__link--active:hover {
  background-color: var(--color-primary-dark);
  color: #fff;
}

/* --- Feature Sections --- */
.feature {
  padding: var(--spacing-3xl) 0;
}

.feature:nth-child(even) {
  background-color: var(--color-bg-alt);
}

.feature__inner {
  max-width: 900px;
  margin: 0 auto;
}

.feature__number {
  display: inline-block;
  font-size: var(--font-size-sm);
  font-weight: 700;
  color: var(--color-primary);
  background: var(--color-primary-light);
  padding: 0.25rem 0.75rem;
  border-radius: 100px;
  margin-bottom: var(--spacing-md);
  letter-spacing: 0.05em;
}

.feature__title {
  font-size: clamp(1.375rem, 3vw, 1.75rem);
  margin-bottom: var(--spacing-lg);
  color: var(--color-text);
}

.feature__text {
  font-size: var(--font-size-base);
  line-height: 1.75;
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-xl);
}

.feature__figure {
  margin: 0;
}

.feature__img {
  width: 100%;
  height: auto;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  border: 1px solid var(--color-border);
  cursor: zoom-in;
  transition: box-shadow 0.3s;
}

.feature__img:hover {
  box-shadow: 0 20px 40px -8px rgba(0, 0, 0, 0.15);
}

.feature__caption {
  margin-top: var(--spacing-sm);
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  text-align: center;
  font-style: italic;
}

/* --- Comparison Table --- */
.comparison {
  padding: var(--spacing-3xl) 0;
}

.comparison__title {
  text-align: center;
  margin-bottom: var(--spacing-md);
}

.comparison__subtitle {
  text-align: center;
  font-size: var(--font-size-lg);
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-2xl);
}

.comparison__wrapper {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow-md);
}

.comparison__table {
  width: 100%;
  min-width: 520px;
  border-collapse: collapse;
  font-size: var(--font-size-sm);
}

.comparison__table thead {
  position: sticky;
  top: 0;
  z-index: 1;
}

.comparison__table th {
  background: var(--color-primary);
  color: #fff;
  font-weight: 600;
  padding: 0.875rem 1rem;
  text-align: center;
  white-space: nowrap;
}

.comparison__table th:first-child {
  text-align: left;
}

.comparison__table td {
  padding: 0.75rem 1rem;
  border-bottom: 1px solid var(--color-border);
  text-align: center;
  color: var(--color-text);
}

.comparison__table td:first-child {
  text-align: left;
  font-weight: 500;
}

.comparison__table tbody tr:last-child td {
  border-bottom: none;
}

.comparison__table tbody tr:hover {
  background-color: var(--color-bg-alt);
}

.comparison__table tr.comparison__row--unique {
  background-color: #EFF6FF;
}

.comparison__table tr.comparison__row--unique:hover {
  background-color: #DBEAFE;
}

.comparison__table tr.comparison__row--unique td:first-child {
  font-weight: 700;
  color: var(--color-primary);
}

.comparison__check {
  color: var(--color-success);
  font-weight: 700;
  font-size: 1.125rem;
}

.comparison__cross {
  color: var(--color-text-secondary);
  opacity: 0.4;
}

/* --- Article CTA --- */
.article-cta {
  padding: var(--spacing-3xl) 0;
  background: linear-gradient(180deg, var(--color-bg) 0%, var(--color-primary-light) 100%);
  text-align: center;
}

.article-cta__title {
  margin-bottom: var(--spacing-md);
}

.article-cta__subtitle {
  font-size: var(--font-size-lg);
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-xl);
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

/* --- Lightbox --- */
.lightbox {
  position: fixed;
  inset: 0;
  z-index: 200;
  background: rgba(0, 0, 0, 0.85);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1rem;
  cursor: zoom-out;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s, visibility 0.3s;
}

.lightbox--open {
  opacity: 1;
  visibility: visible;
}

.lightbox__img {
  max-width: 95vw;
  max-height: 92vh;
  border-radius: var(--radius-md);
  box-shadow: 0 0 60px rgba(0, 0, 0, 0.4);
  object-fit: contain;
}

.lightbox__close {
  position: absolute;
  top: 1rem;
  right: 1rem;
  width: 40px;
  height: 40px;
  background: rgba(255, 255, 255, 0.15);
  border: none;
  border-radius: 50%;
  color: #fff;
  font-size: 1.5rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.2s;
}

.lightbox__close:hover {
  background: rgba(255, 255, 255, 0.3);
}

/* ==========================================================================
   Responsive
   ========================================================================== */

@media (max-width: 639px) {
  .article-hero {
    padding: var(--spacing-2xl) 0 var(--spacing-xl);
  }

  .article-hero__stats {
    gap: var(--spacing-xs);
  }

  .article-hero__badge {
    font-size: 0.75rem;
    padding: 0.375rem 0.75rem;
  }

  .feature {
    padding: var(--spacing-2xl) 0;
  }

  .feature__text {
    font-size: var(--font-size-sm);
  }

  .comparison__table {
    font-size: 0.8125rem;
  }
}

@media (min-width: 640px) {
  .feature {
    padding: var(--spacing-4xl) 0;
  }

  .article-hero {
    padding: var(--spacing-4xl) 0 var(--spacing-2xl);
  }
}

@media (min-width: 1024px) {
  .toc__link {
    font-size: var(--font-size-sm);
    padding: 0.375rem 1rem;
  }
}

/* ==========================================================================
   Reduced Motion
   ========================================================================== */

@media (prefers-reduced-motion: reduce) {
  .lightbox {
    transition: none;
  }
}