/* ============================================================
   BLOG – Article hub + single-post prose styles
   Style: on.energy – high-contrast black/white, industrial
   Linked only on /blog/ pages (in addition to styles.css)
   ============================================================ */

/* ---- Blog index: featured post ---- */
.blog-featured-meta {
  font-size: 0.65rem;
  font-weight: 700;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 1rem;
}

/* ============================================================
   BLOG INDEX — news-site layout (featured + filters + card grid)
   ============================================================ */
:root {
  --amp-salmon: #ee9988;
  --amp-blue:   #99aaee;
  --amp-green:  #9ec5a0;
}

/* Category chip */
.blog-chip {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  width: max-content;
  font-size: 0.58rem;
  font-weight: 700;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  padding: 0.34rem 0.62rem;
  border: 1px solid var(--border-lt);
  color: var(--muted-lt);
}
.blog-chip .d { width: 6px; height: 6px; border-radius: 50%; background: currentColor; }
.blog-chip.thermal { color: var(--amp-salmon); border-color: rgba(238,153,136,0.35); }
.blog-chip.chem    { color: var(--amp-blue);   border-color: rgba(153,170,238,0.35); }
.blog-chip.cell    { color: var(--amp-green);  border-color: rgba(158,197,160,0.35); }
.blog-chip.insight { color: var(--white);      border-color: var(--border-lt); }

/* Shared date + read-time meta row */
.blog-meta {
  display: flex;
  align-items: center;
  gap: 0.55rem;
  font-size: 0.66rem;
  color: var(--muted);
  letter-spacing: 0.03em;
  font-variant-numeric: tabular-nums;
}
.blog-meta .dot { color: var(--border-lt); }

/* Read links (featured + card) */
.blog-readlink,
.blog-readmore {
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--white);
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
}
.blog-readmore { font-size: 0.63rem; margin-top: 0.15rem; }
.blog-readlink .ar,
.blog-readmore .ar { transition: transform var(--transition); }
.blog-readlink:hover .ar { transform: translateX(5px); }

/* Featured story: reuse .news-featured shell, add chip + meta spacing */
.news-featured-image { display: block; }
.news-featured-text .blog-chip { margin-bottom: 1rem; }
.news-featured-text .blog-readlink { margin-bottom: 1.2rem; }

/* Filter row */
.blog-filters {
  display: flex;
  align-items: center;
  gap: 0.55rem;
  flex-wrap: wrap;
  margin: 0.5rem 0 1.75rem;
}
.blog-filters-label {
  font-size: 0.62rem;
  font-weight: 700;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--muted);
  margin-right: 0.4rem;
}
.blog-fbtn {
  font-family: inherit;
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  color: var(--muted-lt);
  padding: 0.48rem 0.95rem;
  border: 1px solid var(--border);
  background: transparent;
  cursor: pointer;
  transition: color var(--transition), border-color var(--transition), background var(--transition);
}
.blog-fbtn:hover { color: var(--white); border-color: var(--border-lt); }
.blog-fbtn.on { background: var(--white); color: #000; border-color: var(--white); }
.blog-fbtn .n { opacity: 0.5; margin-left: 0.35rem; font-variant-numeric: tabular-nums; }

/* Card grid */
.blog-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(324px, 1fr));
  gap: 1px;
  background: var(--border);
  border: 1px solid var(--border);
}
.blog-card {
  background: var(--black);
  display: flex;
  flex-direction: column;
  color: inherit;
  transition: background var(--transition);
}
.blog-card:hover { background: var(--dark-gray); }
.blog-card:hover .blog-readmore .ar { transform: translateX(5px); }
.blog-card:hover .blog-card-art { opacity: 1; }

.blog-card-visual {
  position: relative;
  height: 158px;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  background: radial-gradient(120% 120% at 80% 20%, #121212, #090909);
}
.blog-card-visual.thermal { background: radial-gradient(120% 120% at 80% 20%, #160e0b, #090909); }
.blog-card-visual.chem    { background: radial-gradient(120% 120% at 80% 20%, #0b0f17, #090909); }
.blog-card-visual.cell    { background: radial-gradient(120% 120% at 80% 20%, #0b120c, #090909); }
.blog-card-art { opacity: 0.82; transition: opacity var(--transition); line-height: 0; }

.blog-series-badge {
  position: absolute;
  top: 0.75rem;
  left: 0.75rem;
  font-size: 0.55rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--amp-salmon);
  border: 1px solid rgba(238,153,136,0.3);
  padding: 0.24rem 0.48rem;
  background: rgba(0,0,0,0.35);
}

.blog-card-body {
  padding: 1.25rem 1.35rem 1.4rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  flex: 1;
}
.blog-card-body h3 {
  font-size: 1.14rem;
  font-weight: 700;
  line-height: 1.18;
  letter-spacing: -0.012em;
  color: var(--white);
}
.blog-dek {
  font-size: 0.83rem;
  color: var(--muted-lt);
  line-height: 1.6;
  flex: 1;
}

/* Series note strip */
.blog-series-note {
  margin-top: 2.4rem;
  border: 1px solid var(--border);
  border-left: 2px solid var(--amp-salmon);
  padding: 1.15rem 1.5rem;
  display: flex;
  align-items: center;
  gap: 1rem;
}
.blog-series-note svg { flex-shrink: 0; }
.blog-series-note .st { font-size: 0.82rem; color: var(--light-gray); }
.blog-series-note .st strong { color: var(--amp-salmon); font-weight: 700; letter-spacing: 0.02em; }

@media (max-width: 560px) {
  .blog-grid { grid-template-columns: 1fr; }
}

/* ---- Breadcrumb ---- */
.breadcrumb {
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
  display: flex;
  gap: 0.5rem;
  align-items: center;
  flex-wrap: wrap;
  margin-bottom: 1.5rem;
}
.breadcrumb a { color: var(--muted-lt); transition: color var(--transition); }
.breadcrumb a:hover { color: var(--white); }
.breadcrumb span { color: var(--border-lt); }

/* ============================================================
   SINGLE ARTICLE
   ============================================================ */

/* Centered reading column */
.article-shell {
  max-width: 760px;
  margin: 0 auto;
  padding: 0 2.5rem;
}

.article-header { padding: 130px 0 2.5rem; }
.article-header .article-cat {
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--muted-lt);
  margin-bottom: 1.25rem;
  display: block;
}
.article-header h1 {
  font-size: clamp(2rem, 4.5vw, 3.2rem);
  line-height: 1.05;
  margin-bottom: 1.5rem;
}
.article-byline {
  display: flex;
  gap: 0.75rem;
  align-items: center;
  flex-wrap: wrap;
  font-size: 0.8rem;
  color: var(--muted-lt);
  padding-top: 1.25rem;
  border-top: 1px solid var(--border);
}
.article-byline strong { color: var(--white); font-weight: 600; }
.article-byline .dot { color: var(--border-lt); }

/* Hero image */
.article-hero-image {
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  background: #050505;
  margin-bottom: 3.5rem;
}
.article-hero-image img {
  display: block;
  width: 100%;
  max-height: 520px;
  object-fit: cover;
  filter: grayscale(1) contrast(1.05);
}
.article-hero-image figcaption {
  padding: 0.75rem 2.5rem;
  max-width: 760px;
  margin: 0 auto;
  font-size: 0.68rem;
  color: var(--muted);
}
.article-hero-image figcaption a { color: var(--muted); text-decoration: underline; }

/* Prose body */
.article-body { padding-bottom: 4rem; }
.article-body > * { margin-bottom: 1.5rem; }
.article-body p {
  font-size: 1.05rem;
  line-height: 1.85;
  color: var(--light-gray);
}
.article-body .lead {
  font-size: 1.25rem;
  line-height: 1.65;
  color: var(--white);
  font-weight: 500;
}
.article-body h2 {
  font-size: clamp(1.5rem, 3vw, 2rem);
  margin-top: 3.5rem;
  margin-bottom: 1.25rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border);
  letter-spacing: -0.02em;
}
.article-body h3 {
  font-size: 1.3rem;
  font-weight: 600;
  margin-top: 2.5rem;
  margin-bottom: 1rem;
  color: var(--white);
}
.article-body a {
  color: var(--white);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-color: var(--border-lt);
  transition: text-decoration-color var(--transition);
}
.article-body a:hover { text-decoration-color: var(--white); }

.article-body ul,
.article-body ol { padding-left: 1.5rem; }
.article-body li {
  font-size: 1.05rem;
  line-height: 1.8;
  color: var(--light-gray);
  margin-bottom: 0.6rem;
  padding-left: 0.4rem;
}
.article-body ul li { list-style: none; position: relative; }
.article-body ul li::before {
  content: "";
  position: absolute;
  left: -1.1rem;
  top: 0.72em;
  width: 6px;
  height: 6px;
  background: var(--muted-lt);
}
.article-body ol { list-style: decimal; }
.article-body ol li::marker { color: var(--muted); font-weight: 700; }

.article-body blockquote {
  border-left: 3px solid var(--white);
  padding: 0.5rem 0 0.5rem 2rem;
  margin: 2.5rem 0;
  font-size: 1.35rem;
  line-height: 1.5;
  font-weight: 500;
  color: var(--white);
  letter-spacing: -0.01em;
}

.article-body strong { color: var(--white); font-weight: 600; }

/* Data / comparison table */
.article-table-wrap { overflow-x: auto; margin: 2.5rem 0; }
.article-body table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9rem;
  min-width: 480px;
}
.article-body th,
.article-body td {
  text-align: left;
  padding: 0.9rem 1rem;
  border-bottom: 1px solid var(--border);
}
.article-body thead th {
  font-size: 0.65rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted-lt);
  border-bottom: 1px solid var(--border-lt);
  background: var(--dark-gray);
}
.article-body tbody td { color: var(--light-gray); }
.article-body tbody td:first-child { color: var(--white); font-weight: 500; }

/* Callout box */
.article-callout {
  background: var(--dark-gray);
  border: 1px solid var(--border);
  border-left: 3px solid var(--white);
  padding: 1.75rem 2rem;
  margin: 2.5rem 0;
}
.article-callout p { margin: 0; font-size: 0.95rem; color: var(--muted-lt); line-height: 1.7; }
.article-callout p:first-child { color: var(--white); font-weight: 600; margin-bottom: 0.5rem; }

/* Article footer / back link + related */
.article-end {
  border-top: 1px solid var(--border);
  padding: 2.5rem 0;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
}
.article-back {
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted-lt);
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  transition: gap var(--transition), color var(--transition);
}
.article-back:hover { color: var(--white); gap: 0.9rem; }

@media (max-width: 768px) {
  .article-shell { padding: 0 1.5rem; }
  .article-header { padding: 110px 0 2rem; }
  .article-hero-image figcaption { padding: 0.75rem 1.5rem; }
}