/* ==========================================================================
   BLOG — index + article
   Loads after stylesheet.css and reuses its tokens. No new colours.

   The organising idea: a blog's real structure is chronology, so the date
   is the structural device — mono, left-aligned, and the thing that lights
   up on hover. Work rows get the full indigo wipe; posts stay quieter, so
   the two lists never read as the same component.
   ========================================================================== */

/* Block-level links wrapping headings: state the colour rather than relying
   on the global reset, so these components stay correct on their own. */
.post-feature, .post-row, .post-next a { color: inherit; text-decoration: none; }

/* ---------- Reading progress ----------------------------------------------
   Deliberately identical to the site's .hud-bar — same position, height and
   gradient — because it is the same component doing a more specific job.
   Post pages drop .hud-bar and use this instead, so only ever one renders. */
.read-bar {
  position: fixed;
  top: 0; left: 0;
  z-index: 90;
  height: 2px;
  width: 100%;
  transform: scaleX(var(--read, 0));
  transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--indigo), var(--amber));
  pointer-events: none;
}

/* ---------- Index toolbar ---------- */
.blog-toolbar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  padding-bottom: clamp(18px, 3vh, 30px);
  border-bottom: 1px solid var(--outline-dim);
}
.filter-chip {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  padding: 9px 16px;
  border-radius: var(--radius-pill);
  border: 1px solid var(--ghost);
  color: var(--on-surface-dim);
  background: none;
  cursor: pointer;
  transition: background 0.3s var(--ease), border-color 0.3s, color 0.3s,
              transform 0.3s var(--ease);
}
.filter-chip:hover { transform: translateY(-2px); border-color: var(--outline); color: var(--on-surface); }
.filter-chip[aria-pressed="true"] {
  background: rgba(255, 195, 41, 0.12);
  border-color: rgba(255, 195, 41, 0.4);
  color: var(--amber);
}
.filter-chip:focus-visible { outline: 3px solid var(--periwinkle); outline-offset: 3px; }
.filter-count {
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--outline);
}

/* ---------- Featured post ---------- */
.post-feature {
  position: relative;
  display: block;
  margin: clamp(26px, 4.5vh, 46px) 0 clamp(30px, 5vh, 54px);
  padding: clamp(26px, 4vw, 44px);
  border: 1px solid var(--ghost);
  border-radius: var(--radius-lg);
  background: rgba(255, 255, 255, 0.03);
  text-decoration: none;
  overflow: hidden;
  isolation: isolate;
  transition: transform 0.5s var(--ease), border-color 0.4s var(--ease);
}
.post-feature::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background: radial-gradient(120% 120% at 12% 120%, rgba(70, 72, 212, 0.55), transparent 68%);
  opacity: 0;
  transition: opacity 0.5s var(--ease);
}
.post-feature.is-hidden { display: none; }
.post-feature:hover { transform: translateY(-5px); border-color: rgba(255, 195, 41, 0.4); box-shadow: var(--glow); }
.post-feature:hover::before { opacity: 1; }
.post-feature:focus-visible { outline: 3px solid var(--periwinkle); outline-offset: 4px; }
.post-feature h2 {
  font-weight: 200;
  font-size: clamp(1.9rem, 4.6vw, 3.2rem);
  letter-spacing: -0.04em;
  line-height: 1.02;
  margin: 14px 0 16px;
  max-width: 22ch;
}
.post-feature p {
  color: var(--on-surface-dim);
  font-size: clamp(1rem, 1.4vw, 1.12rem);
  max-width: 60ch;
}
.post-feature .post-more {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  margin-top: 22px;
  font-weight: 700;
  font-size: 14.5px;
  color: var(--amber);
}
.post-feature .arrow { transition: transform 0.4s var(--ease); }
.post-feature:hover .arrow { transform: translateX(6px); }

/* ---------- Post list ---------- */
.post-list { list-style: none; padding: 0; margin: 0; border-top: 1px solid var(--outline-dim); }
.post-list li.is-hidden { display: none; }

.post-row {
  position: relative;
  display: grid;
  grid-template-columns: 92px 1fr auto;
  align-items: baseline;
  gap: 8px 26px;
  padding: clamp(22px, 3.4vh, 34px) 6px;
  border-bottom: 1px solid var(--outline-dim);
  text-decoration: none;
  transition: padding-left 0.5s var(--ease-warp), border-color 0.4s;
}
.post-row:hover, .post-row:focus-visible { padding-left: 20px; border-color: var(--periwinkle); }
.post-row:focus-visible { outline: 3px solid var(--periwinkle); outline-offset: -3px; }

.post-date {
  grid-row: 1 / span 2;
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 500;
  letter-spacing: 0.08em;
  color: var(--outline);
  padding-top: 8px;
  transition: color 0.35s var(--ease);
}
.post-row:hover .post-date { color: var(--amber); }

.post-row h3 {
  font-weight: 200;
  font-size: clamp(1.35rem, 3vw, 2.05rem);
  letter-spacing: -0.03em;
  line-height: 1.1;
  transition: color 0.35s;
}
.post-row:hover h3 { color: var(--white); }
.post-dek {
  grid-column: 2;
  color: var(--on-surface-dim);
  font-size: 15.5px;
  max-width: 62ch;
  margin-top: 8px;
}
.post-read {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--outline);
  white-space: nowrap;
  transition: transform 0.5s var(--ease), color 0.35s;
}
.post-row:hover .post-read { transform: translateX(-4px); color: var(--on-surface-dim); }

.post-tags { display: flex; flex-wrap: wrap; gap: 7px; grid-column: 2; margin-top: 12px; }
.post-tag {
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 500;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--outline);
  border: 1px solid var(--ghost);
  border-radius: var(--radius-pill);
  padding: 4px 10px;
  transition: color 0.35s, border-color 0.35s;
}
.post-row:hover .post-tag { color: var(--on-surface-dim); border-color: var(--outline-dim); }

/* Empty state — an invitation, not an apology */
.post-empty {
  display: none;
  padding: clamp(40px, 8vh, 80px) 0;
  text-align: center;
  color: var(--on-surface-dim);
}
.post-empty.is-shown { display: block; }
.post-empty b { display: block; font-family: var(--font-display); font-weight: 200; font-size: 1.6rem; margin-bottom: 10px; color: var(--on-surface); }

.blog-outro {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 14px;
  padding: clamp(30px, 5vh, 56px) 0 clamp(64px, 11vh, 128px);
  font-size: 15px;
  color: var(--on-surface-dim);
}
.blog-outro a { color: var(--periwinkle); }

/* ==========================================================================
   ARTICLE
   ========================================================================== */
.post-head { max-width: 60ch; }
.post-head h1 {
  font-weight: 200;
  font-size: clamp(2.3rem, 6.4vw, 4.6rem);
  letter-spacing: -0.045em;
  line-height: 0.98;
  margin: 18px 0 22px;
}
.post-byline {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 16px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--outline);
}
.post-byline b { color: var(--on-surface-dim); font-weight: 500; }
.post-byline i { width: 4px; height: 4px; border-radius: 50%; background: var(--amber); }

.article-layout {
  display: grid;
  grid-template-columns: 250px 1fr;
  gap: clamp(32px, 5vw, 76px);
  padding: clamp(20px, 4vh, 44px) 0 clamp(56px, 9vh, 104px);
}
.article-aside {
  position: sticky;
  top: 116px;
  align-self: start;
  display: flex;
  flex-direction: column;
  gap: 26px;
}
.article-aside h4 {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--outline);
  margin-bottom: 10px;
}
.article-aside p { color: var(--on-surface-dim); font-size: 14.5px; }
.toc { list-style: none; padding: 0; display: flex; flex-direction: column; gap: 2px; }
.toc a {
  display: block;
  padding: 7px 0 7px 14px;
  border-left: 1px solid var(--outline-dim);
  font-size: 14px;
  color: var(--on-surface-dim);
  text-decoration: none;
  transition: border-color 0.3s, color 0.3s, padding-left 0.3s var(--ease);
}
.toc a:hover, .toc a.is-here { border-color: var(--amber); color: var(--on-surface); padding-left: 18px; }

/* ---------- Prose ---------- */
.prose { max-width: 68ch; }
.prose > * + * { margin-top: 1.15em; }
.prose p { color: var(--on-surface-dim); font-size: clamp(1.02rem, 1.35vw, 1.14rem); line-height: 1.75; }
.prose .standfirst { color: var(--on-surface); font-size: clamp(1.12rem, 1.7vw, 1.32rem); line-height: 1.6; }
.prose h2 {
  font-weight: 200;
  font-size: clamp(1.6rem, 3.4vw, 2.3rem);
  letter-spacing: -0.035em;
  line-height: 1.1;
  color: var(--on-surface);
  margin-top: 2em;
  scroll-margin-top: 110px;
}
.prose h3 {
  font-weight: 600;
  font-size: 1.16rem;
  letter-spacing: -0.01em;
  color: var(--on-surface);
  margin-top: 1.9em;
  scroll-margin-top: 110px;
}
.prose a { color: var(--periwinkle); text-underline-offset: 4px; }
.prose a:hover { color: var(--amber); }
.prose strong { color: var(--on-surface); font-weight: 700; }
.prose ul, .prose ol { padding-left: 1.25em; color: var(--on-surface-dim); }
.prose li { margin-top: 0.55em; line-height: 1.7; font-size: clamp(1.02rem, 1.35vw, 1.14rem); }
.prose li::marker { color: var(--amber); }
.prose hr { border: 0; border-top: 1px solid var(--outline-dim); margin: 2.6em 0; }

.prose blockquote {
  margin-top: 1.8em;
  padding: 4px 0 4px 26px;
  border-left: 2px solid var(--amber);
  font-family: var(--font-display);
  font-weight: 200;
  font-size: clamp(1.3rem, 2.6vw, 1.75rem);
  letter-spacing: -0.02em;
  line-height: 1.3;
  color: var(--on-surface);
}
.prose blockquote p { font: inherit; color: inherit; line-height: inherit; }

.prose code {
  font-family: var(--font-mono);
  font-size: 0.86em;
  padding: 2px 6px;
  border-radius: 5px;
  background: rgba(143, 146, 255, 0.14);
  color: var(--indigo-lift);
}
.prose pre {
  overflow-x: auto;
  padding: 20px 22px;
  border: 1px solid var(--ghost);
  border-radius: var(--radius-lg);
  background: var(--surface-lowest);
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.65;
  color: var(--on-surface-dim);
  -webkit-overflow-scrolling: touch;
}
.prose pre code { background: none; padding: 0; color: inherit; font-size: inherit; }

.prose figure { margin-top: 1.9em; }
.prose figure img { width: 100%; border-radius: var(--radius-lg); border: 1px solid var(--ghost); display: block; }
.prose figcaption {
  margin-top: 12px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--outline);
}

/* A boxed aside for the "in practice" notes */
.prose .note {
  padding: 20px 22px;
  border: 1px solid var(--ghost);
  border-left: 2px solid var(--indigo-lift);
  border-radius: var(--radius-lg);
  background: rgba(255, 255, 255, 0.03);
}
.prose .note h4 {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--indigo-lift);
  margin-bottom: 8px;
}
.prose .note p { font-size: 15px; margin-top: 0; }

/* ---------- Next post ---------- */
.post-next { border-top: 1px solid var(--outline-dim); }
.post-next a {
  display: block;
  padding: clamp(36px, 6vh, 64px) 0;
  text-decoration: none;
  transition: padding-left 0.5s var(--ease-warp);
}
.post-next a:hover { padding-left: 18px; }
.post-next h2 {
  font-weight: 200;
  font-size: clamp(1.7rem, 4.4vw, 2.9rem);
  letter-spacing: -0.035em;
  margin-top: 10px;
}
.post-next .arrow { color: var(--amber); transition: transform 0.4s var(--ease); display: inline-block; }
.post-next a:hover .arrow { transform: translateX(8px); }

/* ==========================================================================
   RESPONSIVE
   ========================================================================== */
@media (max-width: 900px) {
  .article-layout { grid-template-columns: 1fr; }
  .article-aside { position: static; flex-direction: row; flex-wrap: wrap; gap: 30px; }
  .toc { display: none; }
}
@media (max-width: 620px) {
  .post-row { grid-template-columns: 1fr; gap: 6px; }
  .post-date { grid-row: auto; padding-top: 0; }
  .post-dek, .post-tags { grid-column: 1; }
  .post-read { grid-column: 1; margin-top: 10px; }
  .filter-count { margin-left: 0; width: 100%; }
}

/* ==========================================================================
   REDUCED MOTION
   ========================================================================== */
@media (prefers-reduced-motion: reduce) {
  .read-bar { transition: none; }
  .post-feature:hover, .post-row:hover, .post-next a:hover { transform: none; padding-left: 6px; }
}