/* ============================================================
   AC PORTFOLIO — BASE STYLESHEET
   Light Editorial System v1
   Framework: AC_Portfolio_Frameworkv1
   ============================================================ */

/* ---- Design Tokens ---- */
:root {
  /* Color — Surface */
  --bg: #faf9f7;
  --paper: #ffffff;
  --surface-low: #f4f3f1;
  --surface-mid: #efeeec;
  --surface-high: #e9e8e6;

  /* Color — Ink */
  --ink: #1a1c1b;
  --ink-2: #2f3130;
  --ink-muted: #4e4639;
  --ink-soft: #5f5e5e;
  --ink-faint: rgba(26, 28, 27, 0.55);

  /* Color — Line */
  --line: #e3e2e0;
  --line-soft: rgba(26, 28, 27, 0.08);
  --line-hair: rgba(26, 28, 27, 0.14);

  /* Color — Accent (brass) */
  --accent: #775a19;
  --accent-mid: #a98539;
  --accent-light: #c5a059;
  --accent-wash: rgba(119, 90, 25, 0.07);
  --accent-wash-2: rgba(119, 90, 25, 0.14);

  /* Semantic */
  --focus: #304671;
  --success: #3f6b3a;
  --warning: #8a5a00;

  /* Typography */
  --font-display: "Fraunces", "Times New Roman", Georgia, serif;
  --font-body: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, monospace;

  /* Scale — tightened for a more controlled editorial rhythm below nav */
  --step--1: clamp(0.68rem, 0.66rem + 0.08vw, 0.73rem);
  --step-0:  clamp(0.82rem, 0.80rem + 0.12vw, 0.88rem);
  --step-1:  clamp(0.92rem, 0.89rem + 0.20vw, 1.00rem);
  --step-2:  clamp(1.04rem, 0.98rem + 0.32vw, 1.22rem);
  --step-3:  clamp(1.24rem, 1.13rem + 0.57vw, 1.58rem);
  --step-4:  clamp(1.62rem, 1.43rem + 0.94vw, 2.12rem);
  --step-5:  clamp(2.04rem, 1.72rem + 1.50vw, 2.84rem);
  --step-6:  clamp(2.62rem, 2.08rem + 2.64vw, 4.20rem);
  --step-7:  clamp(3.24rem, 2.43rem + 4.05vw, 5.66rem);

  /* Spacing — tightened without collapsing the editorial air */
  --s-1: 0.19rem;
  --s-2: 0.37rem;
  --s-3: 0.55rem;
  --s-4: 0.72rem;
  --s-5: 1.08rem;
  --s-6: 1.45rem;
  --s-7: 2.17rem;
  --s-8: 2.89rem;
  --s-9: 4.34rem;
  --s-10: 5.78rem;
  --s-11: 8.67rem;

  /* Layout */
  --container: 1360px;
  --container-narrow: 980px;
  --container-prose: 720px;
  --radius-sm: 4px;
  --radius: 8px;
  --radius-lg: 16px;

  /* Motion */
  --ease: cubic-bezier(0.2, 0.6, 0.2, 1);
  --dur-1: 180ms;
  --dur-2: 320ms;
  --dur-3: 520ms;
}

/* ---- Reset ---- */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: var(--step-0);
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}
img, svg, video { display: block; max-width: 100%; height: auto; }
a { color: inherit; text-decoration: none; }
button { font: inherit; cursor: pointer; }
hr { border: 0; border-top: 1px solid var(--line); margin: var(--s-7) 0; }
::selection { background: var(--accent-wash-2); color: var(--accent); }

/* ---- Typography ---- */
.display,
h1.display, h2.display {
  font-family: var(--font-display);
  font-weight: 300;
  font-style: normal;
  letter-spacing: -0.02em;
  line-height: 1.04;
  color: var(--ink);
}
h1 { font-family: var(--font-display); font-weight: 300; letter-spacing: -0.02em; line-height: 1.05; font-size: var(--step-6); margin: 0 0 var(--s-5); }
h2 { font-family: var(--font-display); font-weight: 300; letter-spacing: -0.015em; line-height: 1.1; font-size: var(--step-5); margin: 0 0 var(--s-5); }
h3 { font-family: var(--font-display); font-weight: 400; letter-spacing: -0.01em; line-height: 1.15; font-size: var(--step-3); margin: 0 0 var(--s-4); }
h4 { font-family: var(--font-display); font-weight: 500; letter-spacing: -0.005em; line-height: 1.2; font-size: var(--step-2); margin: 0 0 var(--s-3); }
p  { margin: 0 0 var(--s-4); color: var(--ink-muted); font-size: var(--step-1); line-height: 1.65; }

.lede { font-size: var(--step-2); line-height: 1.45; color: var(--ink); font-weight: 300; letter-spacing: -0.005em; }
.quiet { color: var(--ink-soft); }
.serif { font-family: var(--font-display); }
.mono { font-family: var(--font-mono); font-size: 0.82em; letter-spacing: 0; }
.italic { font-style: italic; }

.eyebrow {
  font-family: var(--font-body);
  font-weight: 500;
  font-size: 0.68rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--ink-muted);
}

.kicker {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
}

/* ---- Layout primitives ---- */
.container   { width: 100%; max-width: var(--container);        margin-inline: auto; padding-inline: clamp(1.25rem, 3vw, 3rem); }
.container-n { width: 100%; max-width: var(--container-narrow); margin-inline: auto; padding-inline: clamp(1.25rem, 3vw, 3rem); }
.container-p { width: 100%; max-width: var(--container-prose);  margin-inline: auto; padding-inline: clamp(1.25rem, 3vw, 2rem); }

.section { padding-block: clamp(3.4rem, 5.95vw, 6.8rem); }
.section-sm { padding-block: clamp(2.15rem, 4.25vw, 4.25rem); }
.section-tight { padding-block: clamp(1.7rem, 2.55vw, 2.55rem); }

.rule { height: 1px; background: var(--line); border: 0; margin: 0; }
.rule-dark { height: 1px; background: var(--ink); opacity: 0.12; border: 0; margin: 0; }

.grid { display: grid; gap: var(--s-6); }
.cols-2 { grid-template-columns: 1fr; }
.cols-3 { grid-template-columns: 1fr; }
.cols-4 { grid-template-columns: 1fr; }
.cols-12 { grid-template-columns: repeat(12, 1fr); }
@media (min-width: 780px) {
  .cols-2 { grid-template-columns: 1fr 1fr; }
  .cols-3 { grid-template-columns: repeat(3, 1fr); }
  .cols-4 { grid-template-columns: repeat(4, 1fr); }
}

.flex { display: flex; gap: var(--s-4); }
.flex.wrap { flex-wrap: wrap; }
.flex.between { justify-content: space-between; }
.flex.center { align-items: center; }
.flex.col { flex-direction: column; }

.stack > * + * { margin-top: var(--s-5); }
.stack-lg > * + * { margin-top: var(--s-7); }
.stack-sm > * + * { margin-top: var(--s-3); }

.muted { color: var(--ink-muted); }
.soft  { color: var(--ink-soft); }
.accent { color: var(--accent); }
.center { text-align: center; }
.right { text-align: right; }

/* ---- Top Nav — scale intentionally NOT reduced; kept at original sizes ---- */
.nav {
  position: sticky; top: 0; z-index: 50;
  backdrop-filter: saturate(180%) blur(14px);
  -webkit-backdrop-filter: saturate(180%) blur(14px);
  background: rgba(250, 249, 247, 0.78);
  border-bottom: 1px solid var(--line-soft);
}
.nav-inner {
  display: flex; align-items: center; justify-content: space-between;
  padding-block: 1.1rem;
}
.brand {
  font-family: var(--font-display);
  font-weight: 300;
  font-size: 1.35rem; /* pinned — exempt from scale reduction */
  letter-spacing: -0.01em;
  color: var(--ink);
  display: flex; align-items: center; gap: 0.55rem;
}
.brand-icon {
  flex: 0 0 auto;
  width: auto;
  height: 36px;
  opacity: 0.9;
  display: block;
  transform: translateY(1px);
}
.brand .mark { color: var(--accent); font-style: italic; }
.nav-links { display: none; gap: clamp(1.25rem, 2vw, 2.25rem); align-items: center; }
.nav-links a {
  font-size: 0.92rem; /* pinned */
  letter-spacing: 0.01em;
  color: var(--ink-soft);
  position: relative;
  padding-block: 2px;
  transition: color var(--dur-2) var(--ease);
}
.nav-links a:hover { color: var(--ink); }
.nav-links a.active { color: var(--accent); }
.nav-links a.active::after {
  content: ""; position: absolute; left: 0; right: 0; bottom: -8px;
  height: 1px; background: var(--accent);
}
.nav-cta {
  font-size: 0.9rem; /* pinned */
  color: var(--accent);
  border: 1px solid var(--accent-wash-2);
  padding: 0.55rem 0.95rem;
  border-radius: 999px;
  transition: background var(--dur-2) var(--ease), border-color var(--dur-2) var(--ease);
}
.nav-cta:hover { background: var(--accent-wash); border-color: var(--accent-light); }
.nav-toggle {
  background: none; border: 0; color: var(--ink);
  display: inline-flex; align-items: center; gap: .4rem; font-size: .9rem; /* pinned */
}
@media (min-width: 880px) {
  .nav-links { display: flex; }
  .nav-toggle { display: none; }
}

/* Mobile menu overlay */
.nav-mobile {
  display: none;
  position: fixed; inset: 0; top: 64px;
  background: var(--bg);
  z-index: 40;
  padding: 2rem clamp(1.25rem, 3vw, 3rem);
  border-top: 1px solid var(--line-soft);
}
.nav-mobile.open { display: block; }
.nav-mobile a { display: block; font-family: var(--font-display); font-size: 2rem; padding: 0.75rem 0; color: var(--ink); }

/* ---- Buttons / Links ---- */
.btn {
  display: inline-flex; align-items: center; gap: .5rem;
  font-size: 0.88rem;
  padding: 0.68rem 1rem;
  border-radius: 999px;
  border: 1px solid var(--ink);
  background: var(--ink);
  color: var(--bg);
  transition: transform var(--dur-1) var(--ease), background var(--dur-2) var(--ease), color var(--dur-2) var(--ease);
}
.btn:hover { background: var(--accent); border-color: var(--accent); color: var(--bg); }
.btn-ghost {
  background: transparent; color: var(--ink); border-color: var(--line-hair);
}
.btn-ghost:hover { background: var(--ink); color: var(--bg); }
.btn-brass {
  background: var(--accent); border-color: var(--accent); color: #fff;
}
.btn-brass:hover { background: var(--ink); border-color: var(--ink); color: var(--bg); }

.link {
  display: inline-flex; align-items: center; gap: .35rem;
  color: var(--accent);
  border-bottom: 1px solid transparent;
  padding-bottom: 1px;
  transition: color var(--dur-2) var(--ease), border-color var(--dur-2) var(--ease);
}
.link:hover { color: var(--ink); border-bottom-color: var(--ink); }
.link .arr { transition: transform var(--dur-2) var(--ease); }
.link:hover .arr { transform: translateX(3px); }

.tag {
  display: inline-flex; align-items: center;
  font-family: var(--font-mono); font-size: 0.68rem;
  letter-spacing: 0.05em; text-transform: uppercase;
  color: var(--ink-muted);
  padding: 0.25rem 0.55rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--paper);
}
.tag.accent { color: var(--accent); border-color: var(--accent-wash-2); background: var(--accent-wash); }

/* ---- Hero ---- */
.hero {
  padding-top: clamp(3rem, 5.1vw, 5.1rem);
  padding-bottom: clamp(3rem, 5.95vw, 5.95rem);
}
.hero .meta {
  display: flex; flex-wrap: wrap; align-items: center;
  gap: 0.9rem; margin-bottom: var(--s-7);
  font-family: var(--font-mono); font-size: 0.74rem;
  letter-spacing: 0.14em; text-transform: uppercase; color: var(--ink-muted);
}
.hero .meta .dot { width: 4px; height: 4px; border-radius: 50%; background: var(--line-hair); }
.hero h1 {
  font-size: var(--step-7);
  max-width: 18ch;
  margin-bottom: var(--s-7);
}
.hero .sub {
  display: grid; grid-template-columns: 1fr; gap: var(--s-6);
  max-width: 62ch;
}
@media (min-width: 980px) {
  .hero .sub { grid-template-columns: 5fr 7fr; gap: var(--s-8); max-width: none; }
}
.hero .sub p { font-size: var(--step-2); line-height: 1.45; color: var(--ink); font-weight: 300; }
.hero .sub .pull {
  font-family: var(--font-display); font-style: italic; font-weight: 300;
  font-size: var(--step-3); color: var(--accent);
  line-height: 1.25; border-left: 1px solid var(--accent-wash-2); padding-left: var(--s-5);
}

main > .section:first-child:not(.hero) h1.display {
  font-size: clamp(2.48rem, 1.8rem + 3.06vw, 4.73rem) !important;
  margin-bottom: 1.7rem !important;
}

/* ---- Proof / Metrics strip ---- */
.proof { background: var(--surface-low); border-top: 1px solid var(--line-soft); border-bottom: 1px solid var(--line-soft); }
.proof .row { display: grid; grid-template-columns: 1fr; gap: var(--s-7); }
@media (min-width: 780px) { .proof .row { grid-template-columns: repeat(3, 1fr); } }
.proof .metric { display: flex; flex-direction: column; gap: 0.35rem; }
.proof .metric .n {
  font-family: var(--font-display);
  font-weight: 300;
  font-size: var(--step-6);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--accent);
}
.proof .metric .l { color: var(--ink-muted); font-size: var(--step-0); max-width: 26ch; }

/* ---- Case card (featured list) ---- */
.case-list { display: grid; gap: var(--s-4); }
.case-row {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--s-5);
  padding: var(--s-6) var(--s-4);
  margin-inline: calc(-1 * var(--s-4));
  border-top: 1px solid var(--line);
  border-radius: var(--radius);
  outline: none;
  transition:
    background var(--dur-2) var(--ease),
    border-color var(--dur-2) var(--ease),
    box-shadow var(--dur-2) var(--ease);
}
.case-row:last-child { border-bottom: 1px solid var(--line); }
.case-row:hover,
.case-row:focus-visible {
  background: var(--surface-low);
  border-color: var(--line-hair);
  box-shadow: inset 0 0 0 1px var(--line-soft);
}
.case-row .idx { font-family: var(--font-mono); font-size: 0.78rem; color: var(--ink-soft); letter-spacing: 0.1em; }
.case-row .meta-col { display: flex; flex-direction: column; gap: 0.5rem; }
.case-row h3 {
  font-family: var(--font-display);
  font-weight: 300;
  font-size: clamp(1.62rem, 1rem + 2.25vw, 2.8rem);
  letter-spacing: -0.015em;
  line-height: 1.05;
  margin: 0;
  transition: color var(--dur-2) var(--ease);
}
.case-row:hover h3,
.case-row:focus-visible h3 { color: var(--accent); }
.case-row .summary { color: var(--ink-muted); max-width: 62ch; font-size: var(--step-1); }
.case-row .tags { display: flex; flex-wrap: wrap; gap: 0.4rem; margin-top: 0.75rem; }
@media (min-width: 980px) {
  .case-row { grid-template-columns: 1fr 6fr; gap: var(--s-7); align-items: baseline; }
}

/* ---- Capability pillars ---- */
.pillars { display: grid; gap: var(--s-6); grid-template-columns: 1fr; }
@media (min-width: 780px) { .pillars { grid-template-columns: repeat(3, 1fr); } }
.pillar {
  border-top: 1px solid var(--ink);
  padding-top: var(--s-5);
  display: flex; flex-direction: column; gap: 0.5rem;
}
.pillar .num { font-family: var(--font-mono); font-size: 0.78rem; color: var(--accent); letter-spacing: 0.12em; }
.pillar h4 { font-family: var(--font-display); font-weight: 400; font-size: var(--step-2); margin: 0; line-height: 1.2; }
.pillar p { margin: 0; color: var(--ink-muted); font-size: var(--step-0); }

/* ============================================================
   Library experience — intro, filter bar, grid, cards, modal
   ============================================================ */

/* ---- Library intro section ---- */
.lib-intro { padding-bottom: clamp(1.7rem, 3.4vw, 3rem); }

/* ---- Sticky filter bar ---- */
.lib-filter-bar {
  position: sticky; top: 64px; z-index: 30;
  background: rgba(250, 249, 247, 0.92);
  backdrop-filter: saturate(180%) blur(14px);
  -webkit-backdrop-filter: saturate(180%) blur(14px);
  border-top: 1px solid var(--line-soft);
  border-bottom: 1px solid var(--line-soft);
  padding-block: 0.85rem;
}
.lib-filter-row {
  display: flex; flex-direction: column;
  gap: 0.85rem;
  align-items: flex-start;
}
.lib-filter-label {
  display: inline-flex; align-items: baseline; gap: 0.75rem;
  flex-shrink: 0;
}
.lib-count {
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink-soft);
}
.lib-controls {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
  width: 100%;
}
@media (min-width: 980px) {
  .lib-filter-row { flex-direction: row; align-items: center; gap: 1.5rem; }
  .lib-controls { flex: 1 1 auto; }
}

/* ---- Library section spacing ---- */
.lib-section {
  padding-block: clamp(2.15rem, 4.25vw, 3.85rem);
}

/* ---- Library grid ---- */
.lib-grid {
  display: grid;
  gap: var(--s-5);
  grid-template-columns: 1fr;
}
@media (min-width: 720px)  { .lib-grid { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 1100px) { .lib-grid { grid-template-columns: repeat(3, 1fr); gap: var(--s-6); } }

/* ---- Library card ---- */
.lib-card {
  display: flex; flex-direction: column;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 0;
  overflow: hidden;
  text-decoration: none;
  color: inherit;
  cursor: pointer;
  position: relative;
  min-height: 292px;
  transition:
    transform var(--dur-2) var(--ease),
    box-shadow var(--dur-2) var(--ease),
    border-color var(--dur-2) var(--ease);
  outline: none;
  opacity: 1;
  animation: libCardIn 320ms var(--ease) both;
}
.lib-card[hidden] { display: none; }
.lib-card.is-shown { animation: libCardIn 320ms var(--ease) both; }

@keyframes libCardIn {
  from { opacity: 0; transform: translateY(8px); }
  to   { opacity: 1; transform: translateY(0); }
}

.lib-card:hover {
  transform: translateY(-3px);
  border-color: var(--accent-wash-2);
  box-shadow: 0 22px 48px -24px rgba(26,28,27,0.28);
}
.lib-card:focus-visible {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-wash-2);
}

/* ---- Homepage library preview ---- */
.home-library-preview {
  border-top: 1px solid var(--line-soft);
  background:
    linear-gradient(180deg, var(--bg) 0%, var(--surface-low) 100%);
}
.home-library-preview .lib-grid {
  gap: var(--s-5);
}
.home-library-preview .lib-card {
  min-height: 0;
}
.home-library-preview .lib-card .lib-media {
  aspect-ratio: 16 / 7;
}
.home-library-preview .lib-card .lib-body {
  padding: 1.15rem 1.15rem 1.25rem;
}
.home-library-preview .lib-card p {
  font-size: var(--step-0);
}
.home-library-preview .chips {
  padding-bottom: var(--s-3);
  border-bottom: 1px solid var(--line-soft);
}
.home-library-preview .chip {
  background: rgba(255, 255, 255, 0.66);
}

.lib-card .lib-media {
  position: relative;
  aspect-ratio: 16 / 10;
  background:
    linear-gradient(135deg, var(--surface-low) 0%, var(--surface-mid) 100%);
  border-bottom: 1px solid var(--line);
  display: flex; align-items: flex-end;
  padding: 0.85rem 1rem;
  overflow: hidden;
}
.lib-card .lib-media::before {
  content: "";
  position: absolute; inset: 0;
  background:
    radial-gradient(60% 80% at 20% 0%, rgba(119,90,25,0.08), transparent 70%),
    repeating-linear-gradient(135deg, transparent 0 22px, rgba(26,28,27,0.025) 22px 23px);
  pointer-events: none;
}
.lib-card .media-tag {
  position: relative;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ink-soft);
  background: rgba(255,255,255,0.7);
  padding: 0.25rem 0.55rem;
  border: 1px solid var(--line-soft);
  border-radius: 999px;
  backdrop-filter: blur(4px);
}

.lib-card .lib-body {
  display: flex; flex-direction: column;
  flex: 1 1 auto;
  padding: 1.06rem 1.06rem 1.28rem;
  gap: 0.47rem;
}
.lib-card .lib-body .k {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 0;
}
.lib-card h4 {
  font-family: var(--font-display);
  font-weight: 400;
  font-size: var(--step-2);
  letter-spacing: -0.01em;
  line-height: 1.22;
  margin: 0;
  color: var(--ink);
  transition: color var(--dur-2) var(--ease);
}
.lib-card:hover h4 { color: var(--accent); }
.lib-card p {
  margin: 0;
  color: var(--ink-muted);
  font-size: var(--step-0);
  line-height: 1.55;
  flex: 1 1 auto;
}
.lib-card .tags {
  display: flex; flex-wrap: wrap; gap: 0.35rem;
  margin-top: 0.5rem;
}
.lib-card .tag {
  font-size: 0.68rem;
  padding: 0.22rem 0.5rem;
  background: var(--surface-low);
  border-color: var(--line-soft);
  color: var(--ink-soft);
}

.lib-card-affordance {
  position: absolute;
  top: 0.85rem; right: 0.95rem;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  opacity: 0;
  transform: translateX(-4px);
  transition: opacity var(--dur-2) var(--ease), transform var(--dur-2) var(--ease);
  background: rgba(255,255,255,0.85);
  padding: 0.25rem 0.55rem;
  border-radius: 999px;
  border: 1px solid var(--accent-wash-2);
  backdrop-filter: blur(4px);
}
.lib-card:hover .lib-card-affordance,
.lib-card:focus-visible .lib-card-affordance {
  opacity: 1;
  transform: translateX(0);
}

/* Empty state */
.lib-empty {
  padding: var(--s-7) 0;
  text-align: center;
}
.link-btn {
  background: none; border: 0; padding: 0;
  color: var(--accent);
  font: inherit;
  cursor: pointer;
  border-bottom: 1px solid var(--accent-wash-2);
  transition: color var(--dur-2) var(--ease), border-color var(--dur-2) var(--ease);
}
.link-btn:hover { color: var(--ink); border-bottom-color: var(--ink); }

/* ---- Category chips (filterable) ---- */
.chips { display: flex; flex-wrap: wrap; gap: 0.5rem; }
.chip {
  display: inline-flex; align-items: center;
  font-family: var(--font-body);
  font-size: 0.8rem;
  font-weight: 500;
  padding: 0.43rem 0.82rem;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: var(--paper);
  color: var(--ink-muted);
  cursor: pointer;
  white-space: nowrap;
  transition:
    background var(--dur-2) var(--ease),
    border-color var(--dur-2) var(--ease),
    color var(--dur-2) var(--ease),
    transform var(--dur-1) var(--ease);
}
.chip:hover { border-color: var(--ink); color: var(--ink); }
.chip:focus-visible {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-wash-2);
}
.chip.active,
.chip.is-active {
  background: var(--ink);
  border-color: var(--ink);
  color: var(--bg);
}
.chip.is-active:hover { background: var(--ink-2); }

/* ---- Library modal ---- */
body.no-scroll { overflow: hidden; }

.lib-modal {
  position: fixed; inset: 0;
  z-index: 100;
  display: flex; align-items: center; justify-content: center;
  padding: clamp(1rem, 4vw, 3rem);
  opacity: 0;
  pointer-events: none;
  transition: opacity 200ms var(--ease);
}
.lib-modal[hidden] { display: none; }
.lib-modal.is-open {
  opacity: 1;
  pointer-events: auto;
}
.lib-modal-overlay {
  position: absolute; inset: 0;
  background: rgba(26, 28, 27, 0.55);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  cursor: pointer;
}
.lib-modal-panel {
  position: relative;
  width: 100%;
  max-width: 760px;
  max-height: calc(100vh - 4rem);
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  box-shadow: 0 50px 100px -30px rgba(26,28,27,0.45);
  display: flex; flex-direction: column;
  overflow: hidden;
  transform: scale(0.97) translateY(8px);
  transition: transform 220ms var(--ease);
  outline: none;
}
.lib-modal.is-open .lib-modal-panel {
  transform: scale(1) translateY(0);
}
.lib-modal-close {
  position: absolute; top: 0.85rem; right: 0.85rem;
  width: 36px; height: 36px;
  display: inline-flex; align-items: center; justify-content: center;
  border: 1px solid var(--line);
  background: var(--paper);
  color: var(--ink-soft);
  border-radius: 50%;
  cursor: pointer;
  z-index: 2;
  transition: color var(--dur-2) var(--ease), border-color var(--dur-2) var(--ease), background var(--dur-2) var(--ease);
}
.lib-modal-close:hover {
  color: var(--ink);
  border-color: var(--ink);
  background: var(--surface-low);
}
.lib-modal-close:focus-visible {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-wash-2);
}

.lib-modal-scroll {
  padding: clamp(1.5rem, 3vw, 2.5rem);
  padding-top: clamp(2.25rem, 4vw, 3rem);
  overflow-y: auto;
}

.lib-modal-meta {
  display: flex; flex-wrap: wrap; gap: 0.6rem;
  align-items: center;
  margin-bottom: 0.85rem;
}
.lib-modal-title {
  font-family: var(--font-display);
  font-weight: 300;
  font-size: clamp(1.53rem, 1.08rem + 1.44vw, 2.16rem);
  line-height: 1.15;
  letter-spacing: -0.015em;
  margin: 0 0 1.25rem;
  color: var(--ink);
  max-width: 28ch;
}
.lib-modal-preview {
  margin-bottom: 1.25rem;
}
.modal-placeholder {
  aspect-ratio: 16 / 9;
  border-radius: var(--radius);
  border: 1px dashed var(--line-hair);
}
.lib-modal-desc {
  font-size: var(--step-1);
  line-height: 1.6;
  color: var(--ink);
  margin: 0 0 1.25rem;
  max-width: 64ch;
}
.lib-modal-tags {
  display: flex; flex-wrap: wrap; gap: 0.4rem;
  margin-bottom: 1.5rem;
}
.lib-modal-actions {
  display: flex; flex-wrap: wrap; gap: 0.6rem;
  align-items: center;
  padding-top: 1rem;
  border-top: 1px solid var(--line-soft);
}

@media (max-width: 600px) {
  .lib-modal { padding: 0.75rem; align-items: flex-end; }
  .lib-modal-panel { max-height: 92vh; border-radius: var(--radius-lg) var(--radius-lg) 0 0; }
}

@media (prefers-reduced-motion: reduce) {
  .lib-card, .lib-modal, .lib-modal-panel { transition: none; animation: none; }
}

/* ---- Case study page ---- */
.cs-hero {
  padding-top: clamp(2.55rem, 4.25vw, 4.25rem);
  padding-bottom: clamp(1.7rem, 2.55vw, 2.55rem);
  border-bottom: 1px solid var(--line);
}
.cs-hero .eyebrow-row {
  display: flex; flex-wrap: wrap; gap: 0.8rem; align-items: center;
  font-family: var(--font-mono); font-size: 0.74rem; letter-spacing: 0.14em;
  text-transform: uppercase; color: var(--ink-muted);
  margin-bottom: var(--s-5);
}
.cs-hero .dot { width: 4px; height: 4px; border-radius: 50%; background: var(--line-hair); }
.cs-hero h1 { font-size: clamp(2.25rem, 1.62rem + 2.88vw, 4.5rem); max-width: 22ch; margin-bottom: var(--s-4); }
.cs-hero .sub { font-size: var(--step-2); color: var(--ink-muted); max-width: 58ch; }

.cs-meta {
  display: grid; gap: var(--s-5);
  grid-template-columns: 1fr 1fr;
  padding-block: var(--s-6);
  border-bottom: 1px solid var(--line);
}
@media (min-width: 780px) { .cs-meta { grid-template-columns: repeat(4, 1fr); } }
.cs-meta .item .label {
  display: block;
  font-family: var(--font-mono); font-size: 0.7rem;
  letter-spacing: 0.15em; text-transform: uppercase; color: var(--ink-soft);
  margin-bottom: 0.35rem;
}
.cs-meta .item .value { font-size: var(--step-0); color: var(--ink); line-height: 1.4; }

.cs-body { padding-block: var(--s-8); }
.cs-body .chapter {
  display: grid; gap: var(--s-5);
  grid-template-columns: 1fr;
  padding-block: var(--s-7);
  border-top: 1px solid var(--line);
}
@media (min-width: 980px) {
  .cs-body .chapter { grid-template-columns: 3fr 9fr; gap: var(--s-8); }
}
.cs-body .chapter:first-child { border-top: 0; padding-top: 0; }
.cs-body .chapter h2 {
  font-family: var(--font-display); font-weight: 300;
  font-size: var(--step-4); letter-spacing: -0.01em;
  line-height: 1.1;
  margin: 0;
}
.cs-body .chapter h2 .num {
  display: block;
  font-family: var(--font-mono); font-size: 0.72rem;
  letter-spacing: 0.18em; text-transform: uppercase;
  color: var(--accent); margin-bottom: 0.5rem;
}
.cs-body .prose p { font-size: var(--step-1); color: var(--ink); line-height: 1.65; max-width: 62ch; }
.cs-body .prose p.quiet { color: var(--ink-muted); }
.cs-body .prose strong { color: var(--ink); font-weight: 600; }
.cs-body .prose ul { margin: 0 0 var(--s-5); padding: 0; list-style: none; max-width: 62ch; }
.cs-body .prose ul li {
  position: relative;
  padding-left: 1.5rem;
  padding-block: 0.4rem;
  border-top: 1px solid var(--line-soft);
  color: var(--ink-muted);
  font-size: var(--step-1);
}
.cs-body .prose ul li::before {
  content: "•"; color: var(--accent);
  position: absolute; left: 0.2rem; top: 0.5rem;
  font-family: var(--font-mono);
}
.cs-body .prose ul li:last-child { border-bottom: 1px solid var(--line-soft); }
.cs-body .pull-quote {
  font-family: var(--font-display); font-style: italic; font-weight: 300;
  font-size: var(--step-3); line-height: 1.3; color: var(--ink);
  border-left: 1px solid var(--accent); padding-left: var(--s-5);
  margin: var(--s-6) 0; max-width: 46ch;
}

.cs-disclaimer {
  background: var(--surface-low); border: 1px solid var(--line);
  padding: var(--s-5); font-size: 0.88rem; color: var(--ink-soft);
  font-family: var(--font-mono); line-height: 1.55;
}

/* ---- Footer ---- */
.foot { background: var(--surface-low); border-top: 1px solid var(--line-soft); }
.foot-inner { display: grid; gap: var(--s-7); grid-template-columns: 1fr; padding-block: var(--s-8); }
@media (min-width: 780px) { .foot-inner { grid-template-columns: 1.2fr 2fr; } }
.foot .col-1 .sig { font-family: var(--font-display); font-size: var(--step-3); font-style: italic; font-weight: 300; }
.foot .col-1 p { color: var(--ink-muted); max-width: 42ch; margin-top: var(--s-3); }
.foot .col-2 { display: grid; gap: var(--s-5); grid-template-columns: 1fr 1fr; }
@media (min-width: 540px) { .foot .col-2 { grid-template-columns: repeat(3, 1fr); } }
.foot h5 { font-family: var(--font-mono); font-size: 0.68rem; text-transform: uppercase; letter-spacing: 0.16em; color: var(--ink-soft); margin: 0 0 0.68rem; }
.foot ul { list-style: none; margin: 0; padding: 0; }
.foot ul li { margin-bottom: 0.34rem; }
.foot ul a { color: var(--ink-muted); font-size: var(--step-0); transition: color var(--dur-2) var(--ease); }
.foot ul a:hover { color: var(--accent); }
.foot .legal {
  border-top: 1px solid var(--line-soft);
  padding-block: var(--s-4);
  display: flex; justify-content: space-between; flex-wrap: wrap; gap: .75rem;
  font-family: var(--font-mono); font-size: 0.7rem; letter-spacing: 0.1em;
  text-transform: uppercase; color: var(--ink-soft);
}

/* ---- Utility ---- */
.sr { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0; }
.hidden { display: none; }
.w-full { width: 100%; }
.rounded { border-radius: var(--radius); }
.rounded-lg { border-radius: var(--radius-lg); }
.border { border: 1px solid var(--line); }
.pt-0 { padding-top: 0 !important; }
.mt-0 { margin-top: 0 !important; }
.mb-0 { margin-bottom: 0 !important; }
.mb-2 { margin-bottom: var(--s-4) !important; }
.mb-4 { margin-bottom: var(--s-6) !important; }
.mb-6 { margin-bottom: var(--s-8) !important; }

/* ---- Editorial figure ---- */
.figure { background: var(--paper); border: 1px solid var(--line); padding: var(--s-5); }
.figure .cap {
  font-family: var(--font-mono); font-size: 0.74rem; color: var(--ink-soft);
  letter-spacing: 0.1em; text-transform: uppercase; margin-top: var(--s-4);
}
.placeholder {
  display: grid; place-items: center;
  aspect-ratio: 16 / 9;
  background: repeating-linear-gradient(135deg,
    var(--surface-mid) 0 10px,
    var(--surface-low) 10px 20px);
  color: var(--ink-soft);
  font-family: var(--font-mono); font-size: 0.82rem;
  letter-spacing: 0.16em; text-transform: uppercase;
  border: 1px dashed var(--line-hair);
}
.placeholder.tall { aspect-ratio: 4 / 5; }

/* ---- In-page nav / anchor rail ---- */
.rail {
  position: sticky; top: 96px;
  display: flex; flex-direction: column;
  gap: 0.35rem;
  padding-top: 0.2rem;
  border-left: 1px solid var(--line);
  padding-left: var(--s-4);
}
.rail a { font-family: var(--font-mono); font-size: 0.74rem; color: var(--ink-soft); letter-spacing: 0.1em; text-transform: uppercase; }
.rail a:hover, .rail a.active { color: var(--accent); }

/* ---- Related work ---- */
.related { border-top: 1px solid var(--line); padding-block: var(--s-8); }
.related .row { display: grid; gap: var(--s-5); grid-template-columns: 1fr; }
@media (min-width: 780px) { .related .row { grid-template-columns: 1fr 1fr; } }
.related a.card {
  display: block; padding: var(--s-5);
  border: 1px solid var(--line); background: var(--paper);
  transition: border-color var(--dur-2) var(--ease), transform var(--dur-1) var(--ease);
}
.related a.card:hover { border-color: var(--accent); transform: translateY(-2px); }
.related .card .k { font-family: var(--font-mono); font-size: 0.72rem; letter-spacing: 0.14em; text-transform: uppercase; color: var(--accent); }
.related .card h4 { margin: 0.35rem 0 0; font-family: var(--font-display); font-weight: 400; font-size: var(--step-3); letter-spacing: -0.01em; }

/* ---- Status tag variants ---- */
.status-pill {
  display: inline-flex; align-items: center; gap: 0.4rem;
  font-family: var(--font-mono); font-size: 0.72rem; text-transform: uppercase; letter-spacing: 0.14em;
  padding: 0.25rem 0.6rem; border-radius: 999px;
  border: 1px solid var(--line-hair); color: var(--ink-soft); background: var(--paper);
}
.status-pill::before { content: ""; width: 6px; height: 6px; border-radius: 50%; background: var(--ink-soft); }
.status-pill.ready::before { background: var(--success); }
.status-pill.ready { color: var(--success); border-color: rgba(63,107,58,0.28); }
.status-pill.progress::before { background: var(--warning); }
.status-pill.progress { color: var(--warning); border-color: rgba(138,90,0,0.28); }
.status-pill.placeholder::before { background: var(--ink-soft); }

/* ---- Systems list (operating principles page) ---- */
.systems-list {
  list-style: none; padding: 0; margin: 0;
  display: grid; grid-template-columns: 1fr; gap: 0;
  border-top: 1px solid var(--line);
}
.systems-item {
  display: grid; grid-template-columns: 72px 1fr; gap: 1.5rem;
  align-items: start;
  padding: 1.7rem 0;
  border-bottom: 1px solid var(--line);
}
@media (min-width: 860px) {
  .systems-item { grid-template-columns: 120px 1fr; gap: 2.55rem; padding: 2.35rem 0; }
}
.systems-item .num {
  font-family: var(--font-mono); font-size: 0.8rem; letter-spacing: 0.14em;
  color: var(--accent); text-transform: uppercase; padding-top: 0.35rem;
}
.systems-item .body h3 {
  font-family: var(--font-display); font-weight: 400; font-size: var(--step-3);
  letter-spacing: -0.012em; line-height: 1.18; margin: 0 0 0.65rem;
  max-width: 34ch;
}
.systems-item .body p { margin: 0; color: var(--ink-soft); max-width: 64ch; }

/* ---- About page extras ---- */
.bio-grid {
  display: grid; grid-template-columns: 1fr; gap: 1.9rem;
}
@media (min-width: 900px) {
  .bio-grid { grid-template-columns: minmax(0,1.4fr) minmax(0,1fr); gap: 3.4rem; }
}
.bio-prose p { margin: 0 0 1rem; max-width: 64ch; color: var(--ink); font-size: var(--step-1); line-height: 1.65; }
.bio-prose p.quiet { color: var(--ink-soft); }
.bio-side { border-left: 1px solid var(--line); padding-left: 2rem; }
@media (max-width: 899px) { .bio-side { border-left: 0; padding-left: 0; border-top: 1px solid var(--line); padding-top: 2rem; } }
.bio-side dl { display: grid; grid-template-columns: 1fr; gap: 1.06rem; margin: 0; }
.bio-side dt { font-family: var(--font-mono); font-size: 0.72rem; letter-spacing: 0.14em; text-transform: uppercase; color: var(--ink-soft); margin-bottom: 0.3rem; }
.bio-side dd { margin: 0; font-size: var(--step-0); line-height: 1.55; color: var(--ink); }

/* ---- Contact page ---- */
.contact-grid {
  display: grid; grid-template-columns: 1fr; gap: 1.28rem;
}
@media (min-width: 760px) {
  .contact-grid { grid-template-columns: repeat(3, 1fr); gap: 1.06rem; }
}
.contact-card {
  display: block; padding: 1.5rem; border: 1px solid var(--line);
  background: var(--paper); color: inherit; text-decoration: none;
  transition: border-color var(--dur-2) var(--ease), transform var(--dur-1) var(--ease);
}
.contact-card:hover { border-color: var(--accent); transform: translateY(-2px); }
.contact-card .k { font-family: var(--font-mono); font-size: 0.72rem; letter-spacing: 0.14em; text-transform: uppercase; color: var(--accent); }
.contact-card h4 { margin: 0.35rem 0 0.35rem; font-family: var(--font-display); font-weight: 400; font-size: 1.35rem; letter-spacing: -0.01em; }
.contact-card p { margin: 0; color: var(--ink-soft); font-size: var(--step-0); }

/* ---- Print ---- */
@media print {
  .nav, .foot, .rail { display: none; }
  body { background: #fff; color: #000; }
  .case-row { break-inside: avoid; }
}