.font-serif { font-family: 'IBM Plex Serif', Georgia, serif; }
  .mono { font-family: 'IBM Plex Mono', ui-monospace, monospace; }
  a { color: inherit; text-decoration: none; }
  
  /* ---------- Buttons ---------- */
  .btn-sm { padding: .5rem .875rem; font-size: .8125rem; }

  /* ---------- Page ---------- */
  .page { max-width: 1160px; margin: 0 auto; padding: 0 1.5rem 5rem; }
  @media (min-width: 768px) { .page { padding: 0 2.5rem 6rem; } }

  .crumb {
    display: flex; align-items: center; gap: .5rem;
    padding: 1.5rem 0 1rem; font-size: .8125rem; color: var(--muted);
  }
  .crumb a { color: var(--muted); transition: color .15s ease; }
  .crumb a:hover { color: var(--ink); }
  .crumb .sep { color: var(--border-strong); }
  .crumb .current { color: var(--ink); font-weight: 500; }

  /* ---------- Blog hero ---------- */
  .blog-hero {
    padding-bottom: 2rem;
    margin-bottom: 2.5rem;
    border-bottom: 1px solid var(--border-strong);
  }
  .blog-eyebrow {
    display: inline-flex; align-items: center; gap: .5rem;
    font-family: 'IBM Plex Mono', monospace;
    font-size: .6875rem; font-weight: 600;
    letter-spacing: .1em; text-transform: uppercase;
    color: var(--accent);
    margin-bottom: 1rem;
  }
  .blog-eyebrow::before {
    content: ''; width: 20px; height: 1px; background: var(--accent);
  }
  .blog-title {
    font-family: 'IBM Plex Serif', Georgia, serif;
    font-size: 2rem; font-weight: 500;
    line-height: 1.15; letter-spacing: -.02em;
    color: var(--ink); margin: 0 0 .75rem;
  }
  @media (min-width: 768px) { .blog-title { font-size: 2.75rem; } }
  .blog-sub {
    font-size: 1.0625rem; line-height: 1.6;
    color: var(--ink-soft); margin: 0;
    max-width: 640px;
  }

  /* ---------- Tag filter ---------- */
  .tag-bar {
    display: flex; flex-wrap: wrap; gap: .5rem;
    padding: 1.25rem 0 2rem;
    margin-bottom: .5rem;
  }
  .tag-btn {
    display: inline-flex; align-items: center; gap: .375rem;
    padding: .4375rem .875rem;
    background: #fff;
    border: 1px solid var(--border);
    border-radius: 20px;
    font-size: .8125rem;
    color: var(--ink-soft);
    cursor: pointer;
    font-family: inherit;
    transition: background .15s ease, border-color .15s ease, color .15s ease;
  }
  .tag-btn:hover { border-color: var(--accent); color: var(--accent); }
  .tag-btn.active {
    background: var(--accent);
    border-color: var(--accent);
    color: #fff;
  }
  .tag-btn .tag-count {
    font-family: 'IBM Plex Mono', monospace;
    font-size: .625rem;
    opacity: .6;
    font-variant-numeric: tabular-nums;
  }
  .tag-btn.active .tag-count { opacity: .8; }

  /* ---------- Featured post ---------- */
  .featured-post {
    display: grid;
    grid-template-columns: 1fr;
    gap: 0;
    background: #fff;
    border: 1px solid var(--border);
    border-radius: 8px;
    overflow: hidden;
    margin-bottom: 3rem;
    transition: border-color .2s ease;
    cursor: pointer;
  }
  @media (min-width: 900px) {
    .featured-post { grid-template-columns: 1.1fr 1fr; }
  }
  .featured-post:hover { border-color: var(--accent); }

  .featured-cover {
    min-height: 240px;
    position: relative;
    background: var(--accent);
    overflow: hidden;
    display: flex; align-items: center; justify-content: center;
    padding: 2rem;
  }
  @media (min-width: 900px) {
    .featured-cover { min-height: 360px; }
  }
  .featured-cover::before {
    content: '';
    position: absolute; inset: 0;
    background-image: repeating-linear-gradient(
      45deg,
      transparent,
      transparent 24px,
      rgba(255,255,255,.06) 24px,
      rgba(255,255,255,.06) 25px
    );
    pointer-events: none;
  }
  .featured-cover-inner {
    position: relative;
    text-align: center;
    color: #fff;
  }
  .featured-cover-label {
    font-family: 'IBM Plex Mono', monospace;
    font-size: .6875rem; font-weight: 600;
    letter-spacing: .12em; text-transform: uppercase;
    color: rgba(255,255,255,.65);
    margin-bottom: 1rem;
  }
  .featured-cover-number {
    font-family: 'IBM Plex Serif', Georgia, serif;
    font-size: 4rem; font-weight: 500;
    line-height: 1;
    letter-spacing: -.03em;
    font-variant-numeric: tabular-nums;
  }
  @media (min-width: 900px) {
    .featured-cover-number { font-size: 5.5rem; }
  }
  .featured-cover-desc {
    font-size: .8125rem;
    color: rgba(255,255,255,.75);
    margin-top: .75rem;
    letter-spacing: .02em;
  }

  .featured-body {
    padding: 1.75rem 1.75rem 2rem;
    display: flex; flex-direction: column;
    justify-content: center;
  }
  @media (min-width: 768px) {
    .featured-body { padding: 2.5rem 2.75rem; }
  }

  .post-cat {
    display: inline-flex; align-items: center; gap: .375rem;
    font-family: 'IBM Plex Mono', monospace;
    font-size: .6875rem; font-weight: 600;
    letter-spacing: .06em; text-transform: uppercase;
    color: var(--accent);
    margin-bottom: .875rem;
  }
  .post-cat::before {
    content: ''; width: 5px; height: 5px;
    background: var(--accent); border-radius: 50%;
  }

  .featured-title {
    font-family: 'IBM Plex Serif', Georgia, serif;
    font-size: 1.5rem; font-weight: 500;
    line-height: 1.25; letter-spacing: -.015em;
    color: var(--ink);
    margin: 0 0 1rem;
  }
  @media (min-width: 768px) {
    .featured-title { font-size: 1.875rem; }
  }

  .featured-excerpt {
    font-size: 1rem; line-height: 1.65;
    color: var(--ink-soft);
    margin: 0 0 1.5rem;
  }

  .post-meta {
    display: flex; align-items: center; flex-wrap: wrap;
    gap: .75rem;
    font-size: .8125rem; color: var(--muted);
    font-variant-numeric: tabular-nums;
  }
  .post-meta .dot { color: var(--border-strong); }
  .post-meta strong { color: var(--ink); font-weight: 500; }
  .post-meta-author {
    display: inline-flex; align-items: center; gap: .5rem;
  }
  .post-meta-avatar {
    width: 24px; height: 24px; border-radius: 50%;
    background: var(--accent-soft); color: var(--accent);
    display: inline-flex; align-items: center; justify-content: center;
    font-size: .625rem; font-weight: 600;
    flex-shrink: 0;
  }

  /* ---------- Blog grid + sidebar ---------- */
  .blog-layout {
    display: grid;
    grid-template-columns: 1fr;
    gap: 3rem;
  }
  @media (min-width: 1024px) {
    .blog-layout {
      grid-template-columns: minmax(0, 1fr) 300px;
      gap: 4rem;
      align-items: start;
    }
  }

  .post-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 2rem;
  }
  @media (min-width: 640px) {
    .post-grid { grid-template-columns: repeat(2, 1fr); }
  }

  .post-card {
    cursor: pointer;
    display: flex; flex-direction: column;
    border-top: 1px solid var(--border);
    padding-top: 1.25rem;
    transition: border-color .15s ease;
  }
  .post-card:hover { border-top-color: var(--accent); }

  .post-card-cat {
    display: inline-flex; align-items: center; gap: .375rem;
    font-family: 'IBM Plex Mono', monospace;
    font-size: .625rem; font-weight: 600;
    letter-spacing: .06em; text-transform: uppercase;
    color: var(--muted);
    margin-bottom: .625rem;
  }
  .post-card-cat .cat-dot {
    width: 5px; height: 5px; border-radius: 50%;
    background: var(--muted);
  }
  .post-card[data-cat="product"] .post-card-cat .cat-dot { background: var(--accent); }
  .post-card[data-cat="product"] .post-card-cat { color: var(--accent); }
  .post-card[data-cat="policy"] .post-card-cat .cat-dot { background: var(--warning); }
  .post-card[data-cat="policy"] .post-card-cat { color: var(--warning); }
  .post-card[data-cat="story"] .post-card-cat .cat-dot { background: var(--success); }
  .post-card[data-cat="story"] .post-card-cat { color: var(--success); }
  .post-card[data-cat="engineering"] .post-card-cat .cat-dot { background: #6b4f8a; }
  .post-card[data-cat="engineering"] .post-card-cat { color: #6b4f8a; }

  .post-card-title {
    font-family: 'IBM Plex Serif', Georgia, serif;
    font-size: 1.125rem; font-weight: 500;
    line-height: 1.35; letter-spacing: -.005em;
    color: var(--ink);
    margin: 0 0 .625rem;
    transition: color .15s ease;
  }
  .post-card:hover .post-card-title { color: var(--accent); }

  .post-card-excerpt {
    font-size: .875rem; line-height: 1.6;
    color: var(--ink-soft);
    margin: 0 0 1rem;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
  }

  .post-card-meta {
    font-size: .75rem; color: var(--muted);
    display: flex; align-items: center; gap: .5rem;
    flex-wrap: wrap;
    margin-top: auto;
    font-variant-numeric: tabular-nums;
  }
  .post-card-meta .dot { color: var(--border-strong); }

  /* ---------- Sidebar ---------- */
  .side-card-blog {
    background: #fff;
    border: 1px solid var(--border);
    border-radius: 8px;
    overflow: hidden;
    margin-bottom: 1.25rem;
  }
  .side-card-blog:last-child { margin-bottom: 0; }
  .side-card-blog-head {
    padding: .875rem 1.25rem;
    background: var(--bg-alt);
    border-bottom: 1px solid var(--border);
    font-family: 'IBM Plex Mono', monospace;
    font-size: .6875rem; font-weight: 600;
    letter-spacing: .08em; text-transform: uppercase;
    color: var(--muted);
  }
  .side-card-blog-body { padding: 1.125rem 1.25rem; }

  /* Popular posts */
  .popular-item {
    display: flex; gap: .875rem;
    padding: .875rem 0;
    border-bottom: 1px solid var(--border);
    cursor: pointer;
    align-items: flex-start;
  }
  .popular-item:first-child { padding-top: 0; }
  .popular-item:last-child { padding-bottom: 0; border-bottom: none; }
  .popular-num {
    font-family: 'IBM Plex Mono', monospace;
    font-size: .75rem; font-weight: 600;
    color: var(--muted-2);
    letter-spacing: .04em;
    min-width: 1.25rem;
    padding-top: .125rem;
  }
  .popular-item:nth-child(1) .popular-num,
  .popular-item:nth-child(2) .popular-num,
  .popular-item:nth-child(3) .popular-num {
    color: var(--accent);
  }
  .popular-info { min-width: 0; flex: 1; }
  .popular-title {
    font-size: .8125rem; font-weight: 500;
    color: var(--ink);
    line-height: 1.4;
    margin: 0 0 .25rem;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
    transition: color .15s ease;
  }
  .popular-item:hover .popular-title { color: var(--accent); }
  .popular-meta {
    font-size: .6875rem; color: var(--muted);
    display: flex; align-items: center; gap: .375rem;
  }
  .popular-meta .dot { color: var(--border-strong); }

  /* Newsletter */
  .newsletter {
    background: var(--accent);
    color: #fff;
    border-radius: 8px;
    padding: 1.5rem 1.5rem 1.75rem;
    margin-bottom: 1.25rem;
    position: relative;
    overflow: hidden;
  }
  .newsletter::before {
    content: '';
    position: absolute; inset: 0;
    background-image: repeating-linear-gradient(
      45deg,
      transparent,
      transparent 20px,
      rgba(255,255,255,.05) 20px,
      rgba(255,255,255,.05) 21px
    );
    pointer-events: none;
  }
  .newsletter-inner { position: relative; }
  .newsletter-eyebrow {
    font-family: 'IBM Plex Mono', monospace;
    font-size: .625rem; font-weight: 600;
    letter-spacing: .1em; text-transform: uppercase;
    color: rgba(255,255,255,.65);
    margin-bottom: .625rem;
  }
  .newsletter-title {
    font-family: 'IBM Plex Serif', Georgia, serif;
    font-size: 1.125rem; font-weight: 500;
    line-height: 1.35;
    letter-spacing: -.005em;
    margin: 0 0 .5rem;
  }
  .newsletter-desc {
    font-size: .8125rem;
    color: rgba(255,255,255,.8);
    line-height: 1.55;
    margin: 0 0 1rem;
  }
  .newsletter-form {
    display: flex;
    flex-direction: column;
    gap: .5rem;
  }
  .newsletter-form input {
    width: 100%;
    padding: .625rem .75rem;
    font-size: .875rem; font-family: inherit;
    color: var(--ink);
    background: #fff;
    border: 1px solid transparent;
    border-radius: 6px;
  }
  .newsletter-form input:focus {
    outline: none;
    border-color: #fff;
    box-shadow: 0 0 0 3px rgba(255,255,255,.25);
  }
  .newsletter-form input::placeholder { color: var(--muted-2); }
  .newsletter-form button {
    padding: .625rem .75rem;
    font-size: .875rem; font-weight: 500;
    font-family: inherit;
    background: rgba(255,255,255,.15);
    color: #fff;
    border: 1px solid rgba(255,255,255,.25);
    border-radius: 6px;
    cursor: pointer;
    transition: background .15s ease, border-color .15s ease;
  }
  .newsletter-form button:hover {
    background: rgba(255,255,255,.25);
    border-color: rgba(255,255,255,.4);
  }
  .newsletter-note {
    font-size: .6875rem;
    color: rgba(255,255,255,.6);
    margin-top: .75rem;
    line-height: 1.5;
  }

  /* Topics */
  .topic-list {
    display: flex; flex-wrap: wrap; gap: .375rem;
  }
  .topic-tag {
    display: inline-flex; align-items: center;
    padding: .3125rem .625rem;
    background: var(--bg-alt);
    border: 1px solid var(--border);
    border-radius: 4px;
    font-size: .75rem;
    color: var(--ink-soft);
    cursor: pointer;
    transition: background .15s ease, border-color .15s ease, color .15s ease;
  }
  .topic-tag:hover {
    background: var(--accent-soft);
    border-color: var(--accent);
    color: var(--accent);
  }
  .topic-tag .topic-count {
    margin-left: .375rem;
    font-family: 'IBM Plex Mono', monospace;
    font-size: .625rem;
    color: var(--muted-2);
  }

  /* Load more */
  .load-more {
    display: flex; justify-content: center;
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border);
  }

  /* Empty */
  .empty-blog {
    grid-column: 1 / -1;
    padding: 3rem 1.5rem;
    text-align: center;
    border: 1px dashed var(--border-strong);
    border-radius: 8px;
  }
  .empty-blog-title {
    font-size: .9375rem; font-weight: 500;
    color: var(--ink);
    margin: 0 0 .375rem;
  }
  .empty-blog-desc {
    font-size: .875rem; color: var(--muted);
    line-height: 1.55;
    margin: 0;
  }

  /* ---------- Toast ---------- */
  .toast {
    position: fixed; bottom: 1.5rem; left: 50%;
    transform: translateX(-50%) translateY(120%);
    background: var(--ink); color: #fff; font-size: .875rem;
    padding: .75rem 1.25rem; border-radius: 6px; z-index: 120;
    box-shadow: 0 4px 16px rgba(0,0,0,.12);
    transition: transform .25s ease;
    display: flex; align-items: center; gap: .625rem;
    max-width: calc(100vw - 2rem);
  }
  .toast.on { transform: translateX(-50%) translateY(0); }
  .toast .check {
    width: 16px; height: 16px; border-radius: 50%; background: var(--success);
    display: inline-flex; align-items: center; justify-content: center; flex-shrink: 0;
  }

  @media (prefers-reduced-motion: reduce) {
    * { animation-duration: .01ms !important; transition-duration: .01ms !important; }
  }