/*
 * Blog surface for SPHEN.AI.
 *
 * Loads on top of design-tokens.css and legal.css: those own the reset, the
 * floating header, the footer, buttons, and focus treatment. Everything here is
 * blog-specific and uses design tokens only.
 */

.blog-main,
.article-main {
  width: min(1120px, calc(100% - 32px));
  margin: 0 auto;
  padding: calc(var(--space-24) + 48px) 0 var(--space-24);
}

/* Index hero */

.blog-hero {
  max-width: var(--measure-body);
  margin-bottom: var(--space-16);
}

.blog-kicker,
.article-kicker {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  margin-bottom: var(--space-4);
  padding: var(--space-1) var(--space-3);
  border: 1px solid var(--color-border-signal-soft);
  border-radius: var(--radius-pill);
  background: var(--color-signal-wash);
  color: var(--color-text-secondary);
  font-size: var(--text-label);
  font-weight: 600;
  letter-spacing: 0.02em;
  text-transform: uppercase;
}

.blog-title {
  margin: 0 0 var(--space-5);
  font-size: var(--text-heading);
  font-weight: 680;
  letter-spacing: -0.02em;
  line-height: var(--leading-heading);
}

.blog-lead {
  margin: 0;
  color: var(--color-text-secondary);
  font-size: var(--text-lead);
  line-height: var(--leading-body);
}

/* Article index */

.article-list {
  display: grid;
  gap: var(--space-6);
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  list-style: none;
  margin: 0;
  padding: 0;
}

.article-card {
  display: flex;
  height: 100%;
  flex-direction: column;
  overflow: hidden;
  border: 1px solid var(--color-border-default);
  border-radius: var(--radius-panel);
  background: var(--color-surface-raised);
  box-shadow: 0 1px 2px var(--color-shadow-subtle);
  color: inherit;
  text-decoration: none;
  transition:
    border-color var(--duration-fast) var(--ease-out),
    box-shadow var(--duration-base) var(--ease-out),
    transform var(--duration-base) var(--ease-out);
}

.article-card:hover {
  border-color: var(--color-border-signal);
  box-shadow: 0 12px 28px var(--color-shadow-medium);
  transform: translateY(-2px);
}

.article-card:focus-visible,
.article-prose a:focus-visible,
.article-cta a:focus-visible {
  outline: 3px solid var(--color-focus-ring);
  outline-offset: 2px;
  box-shadow: 0 0 0 5px var(--color-focus-contrast);
}

.article-card__figure {
  position: relative;
  overflow: hidden;
  padding-top: 62.5%;
  background: var(--color-surface-tinted);
}

.article-card__figure img {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--duration-slow) var(--ease-out);
}

.article-card:hover .article-card__figure img:not(.article-card__fallback) {
  transform: scale(1.03);
}

/* An article without artwork keeps the same tile height, so titles across a
   row stay on one baseline instead of stepping. */
.article-card__figure .article-card__fallback {
  top: 50%;
  left: 50%;
  width: 56px;
  height: 56px;
  object-fit: contain;
  opacity: 0.32;
  transform: translate(-50%, -50%);
}

.article-card__body {
  display: flex;
  flex: 1 1 auto;
  flex-direction: column;
  gap: var(--space-3);
  padding: var(--space-6);
}

.article-card__title {
  margin: 0;
  font-size: var(--text-lead);
  font-weight: 640;
  letter-spacing: -0.01em;
  line-height: var(--leading-heading);
}

.article-card__excerpt {
  margin: 0;
  color: var(--color-text-secondary);
  font-size: var(--text-body);
  line-height: var(--leading-body);
}

.article-card__meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-2);
  margin-top: auto;
  padding-top: var(--space-2);
  color: var(--color-text-muted);
  font-size: var(--text-label);
}

.article-card__meta span[aria-hidden="true"] {
  color: var(--color-border-strong);
}

/* The index mixes both languages, so each card states its own. */
.article-card__lang {
  margin-left: auto;
  padding: 2px var(--space-2);
  border: 1px solid var(--color-border-default);
  border-radius: var(--radius-pill);
  font-size: var(--text-caption);
  font-weight: 600;
  letter-spacing: 0.04em;
}

.article-card:hover .article-card__lang {
  border-color: var(--color-border-signal);
}

/* One staggered reveal on load reads as intent; per-element motion would just
   be noise on a page whose job is reading. */
@media (prefers-reduced-motion: no-preference) {
  .article-list > li {
    animation: article-card-in var(--duration-slow) var(--ease-out) both;
  }

  .article-list > li:nth-child(1) { animation-delay: 0ms; }
  .article-list > li:nth-child(2) { animation-delay: 60ms; }
  .article-list > li:nth-child(3) { animation-delay: 120ms; }
  .article-list > li:nth-child(n + 4) { animation-delay: 180ms; }

  .blog-hero > * {
    animation: article-card-in var(--duration-slow) var(--ease-out) both;
  }

  .blog-kicker { animation-delay: 0ms; }
  .blog-title { animation-delay: 40ms; }
  .blog-lead { animation-delay: 80ms; }
}

@keyframes article-card-in {
  from {
    opacity: 0;
    transform: translateY(8px);
  }

  to {
    opacity: 1;
    transform: none;
  }
}

/* Related articles */

.article-related {
  margin-top: var(--space-24);
  padding-top: var(--space-12);
  border-top: 1px solid var(--color-border-default);
}

.article-related__title {
  margin: 0 0 var(--space-8);
  font-size: var(--text-subhead);
  font-weight: 660;
  letter-spacing: -0.015em;
  line-height: var(--leading-heading);
}

.blog-empty {
  margin: 0;
  padding: var(--space-12);
  border: 1px dashed var(--color-border-strong);
  border-radius: var(--radius-panel);
  color: var(--color-text-secondary);
  text-align: center;
}

/* Article page */

.article-main {
  width: min(1120px, calc(100% - 32px));
}

.article-header {
  max-width: var(--measure-body);
  margin-bottom: var(--space-10);
}

.article-title {
  margin: 0 0 var(--space-5);
  font-size: var(--text-heading);
  font-weight: 680;
  letter-spacing: -0.02em;
  line-height: var(--leading-heading);
}

.article-lead {
  margin: 0 0 var(--space-6);
  color: var(--color-text-secondary);
  font-size: var(--text-lead);
  line-height: var(--leading-body);
}

.article-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-2);
  color: var(--color-text-muted);
  font-size: var(--text-label);
}

.article-meta span[aria-hidden="true"] {
  color: var(--color-border-strong);
}

.article-figure {
  margin: 0 0 var(--space-12);
  overflow: hidden;
  border: 1px solid var(--color-border-default);
  border-radius: var(--radius-panel);
  background: var(--color-surface-tinted);
}

.article-figure img {
  width: 100%;
  height: auto;
}

.article-figure figcaption {
  padding: var(--space-3) var(--space-5);
  border-top: 1px solid var(--color-border-subtle);
  color: var(--color-text-muted);
  font-size: var(--text-label);
}

/* Prose */

.article-prose {
  max-width: var(--measure-body);
  font-size: var(--text-body);
  line-height: var(--leading-body);
}

.article-prose > * + * {
  margin-top: var(--space-5);
}

.article-prose h2 {
  margin-top: var(--space-12);
  font-size: var(--text-subhead);
  font-weight: 660;
  letter-spacing: -0.015em;
  line-height: var(--leading-heading);
}

.article-prose h3 {
  margin-top: var(--space-10);
  font-size: var(--text-lead);
  font-weight: 640;
  line-height: var(--leading-heading);
}

.article-prose p,
.article-prose li {
  color: var(--color-text-secondary);
}

.article-prose strong {
  color: var(--color-text-primary);
  font-weight: 640;
}

.article-prose a {
  color: var(--color-text-primary);
  text-decoration: underline;
  text-decoration-color: var(--color-signal-underline);
  text-decoration-thickness: 2px;
  text-underline-offset: 3px;
  transition: text-decoration-color var(--duration-fast) var(--ease-out);
}

.article-prose a:hover {
  text-decoration-color: var(--color-brand-signal);
}

.article-prose ul,
.article-prose ol {
  padding-left: var(--space-6);
}

.article-prose li + li {
  margin-top: var(--space-2);
}

.article-prose blockquote {
  margin-left: 0;
  margin-right: 0;
  padding: var(--space-2) 0 var(--space-2) var(--space-6);
  border-left: 3px solid var(--color-brand-signal);
  color: var(--color-text-primary);
  font-size: var(--text-lead);
  line-height: var(--leading-body);
}

.article-prose code {
  padding: 0.1em 0.35em;
  border: 1px solid var(--color-border-subtle);
  border-radius: var(--radius-control);
  background: var(--color-surface-muted);
  font-size: 0.9em;
}

.article-prose pre {
  overflow-x: auto;
  padding: var(--space-5);
  border: 1px solid var(--color-border-default);
  border-radius: var(--radius-panel);
  background: var(--color-surface-inverse);
  color: var(--color-text-inverse);
}

.article-prose pre code {
  padding: 0;
  border: 0;
  background: none;
  color: inherit;
}

.article-prose img {
  border-radius: var(--radius-panel);
}

.article-prose figure {
  margin-left: 0;
  margin-right: 0;
}

/* Tables have to stay scrollable instead of widening the page. */
.article-prose table {
  display: block;
  width: 100%;
  overflow-x: auto;
  border-collapse: collapse;
  font-size: var(--text-label);
}

.article-prose th,
.article-prose td {
  padding: var(--space-3) var(--space-4);
  border-bottom: 1px solid var(--color-border-subtle);
  text-align: left;
  vertical-align: top;
}

.article-prose th {
  border-bottom-color: var(--color-border-strong);
  color: var(--color-text-primary);
  font-weight: 640;
  white-space: nowrap;
}

.article-prose hr {
  height: 1px;
  margin: var(--space-12) 0;
  border: 0;
  background: var(--color-border-default);
}

/* Article footer */

.article-cta {
  max-width: var(--measure-body);
  margin-top: var(--space-16);
  padding: var(--space-8);
  border: 1px solid var(--color-border-ocean-soft);
  border-radius: var(--radius-panel);
  background: var(--color-surface-tinted);
}

.article-cta h2 {
  margin: 0 0 var(--space-3);
  font-size: var(--text-lead);
  font-weight: 660;
  line-height: var(--leading-heading);
}

.article-cta p {
  margin: 0 0 var(--space-5);
  color: var(--color-text-secondary);
  line-height: var(--leading-body);
}

@media (max-width: 640px) {
  .blog-main,
  .article-main {
    padding-top: calc(var(--space-16) + 48px);
  }

  .article-list {
    grid-template-columns: 1fr;
  }
}

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

  .article-card:hover {
    transform: none;
  }
}