/*
 * projects.css — Lab notebook treatment.
 * - Project sigils, category hue hairlines, chapter numbers
 * - On-this-page right rail
 * - Scroll-driven progress bar
 */

/* ── Category hues ─────────────────────────────────────────────────────── */
:root {
  --hue-default: var(--accent);
  --hue-oss:     oklch(58% 0.14 145);   /* green */
  --hue-ml:      oklch(60% 0.16 230);   /* blue-teal */
  --hue-sec:     oklch(58% 0.18 25);    /* warm red */
  --hue-robo:    oklch(68% 0.14 60);    /* amber */
  --hue-net:     oklch(55% 0.16 290);   /* indigo-violet */
  --hue-research: var(--accent);
}

html.dark {
  --hue-oss:     oklch(72% 0.13 145);
  --hue-ml:      oklch(72% 0.14 230);
  --hue-sec:     oklch(72% 0.16 30);
  --hue-robo:    oklch(78% 0.13 65);
  --hue-net:     oklch(70% 0.14 290);
}

/* ── Docs shell ─────────────────────────────────────────────────────────── */
.docs-layout {
  display: grid;
  grid-template-columns: 240px minmax(0, 1fr) 200px;
  grid-template-rows: auto 1fr;
  min-height: 100dvh;
  max-width: 1280px;
  margin: 0 auto;
  position: relative;
}

/* Hairline tint at top of project pages (1px, category-derived) */
.docs-hairline {
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 1px;
  z-index: 51;
  background: var(--hue-default);
}
.docs-hairline[data-hue="oss"]      { background: var(--hue-oss); }
.docs-hairline[data-hue="ml"]       { background: var(--hue-ml); }
.docs-hairline[data-hue="sec"]      { background: var(--hue-sec); }
.docs-hairline[data-hue="robo"]     { background: var(--hue-robo); }
.docs-hairline[data-hue="net"]      { background: var(--hue-net); }
.docs-hairline[data-hue="research"] { background: var(--hue-research); }

/* Scroll-driven progress bar (Chrome/Edge/Safari). Fallback: invisible. */
.docs-progress {
  position: fixed;
  top: 0; left: 0;
  width: 0;
  height: 2px;
  background: var(--accent);
  z-index: 52;
  transform-origin: 0 50%;
  pointer-events: none;
}
@supports (animation-timeline: scroll()) {
  .docs-progress {
    width: 100%;
    transform: scaleX(0);
    animation: docs-progress-scale linear;
    animation-timeline: scroll();
  }
  @keyframes docs-progress-scale {
    to { transform: scaleX(1); }
  }
}

/* ── Topbar ────────────────────────────────────────────────────────────── */
.docs-topbar {
  grid-column: 1 / -1;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--sp-4);
  padding: var(--sp-3) var(--sp-5);
  border-bottom: 1px solid var(--rule);
  position: sticky;
  top: 0;
  z-index: 50;
  background: var(--bg);
}

.docs-topbar__project {
  display: inline-flex;
  align-items: center;
  gap: var(--sp-3);
  font-family: var(--font-sans);
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--fg);
  text-decoration: none;
}

.docs-topbar__sigil {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 500;
  letter-spacing: 0.06em;
  color: var(--fg-3);
  padding: 2px 6px;
  border: 1px solid var(--rule);
  border-radius: 2px;
}

.docs-topbar__breadcrumb {
  display: flex;
  align-items: center;
  gap: var(--sp-2);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.02em;
  color: var(--fg-3);
  flex: 1;
}
.docs-topbar__breadcrumb a {
  color: var(--fg-3);
  text-decoration: none;
  transition: color 180ms cubic-bezier(0.16, 1, 0.3, 1);
}
.docs-topbar__breadcrumb a:hover,
.docs-topbar__breadcrumb a:focus-visible { color: var(--accent); }
.docs-topbar__breadcrumb .sep { color: var(--fg-3); opacity: 0.5; }

/* ── Sidebar ───────────────────────────────────────────────────────────── */
.docs-sidebar {
  grid-column: 1;
  grid-row: 2;
  padding: var(--sp-5) 0;
  border-right: 1px solid var(--rule);
  position: sticky;
  top: 56px;
  max-height: calc(100dvh - 56px);
  overflow-y: auto;
  scrollbar-width: thin;
  scrollbar-color: var(--rule) transparent;
}
.docs-sidebar::-webkit-scrollbar { width: 4px; }
.docs-sidebar::-webkit-scrollbar-thumb { background: var(--rule); border-radius: 2px; }

.docs-sidebar__title {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  padding: 0 var(--sp-5) var(--sp-4);
  margin-bottom: var(--sp-3);
  border-bottom: 1px solid var(--rule);
}

.docs-sidebar__title span:last-child {
  font-family: var(--font-serif);
  font-variation-settings: "opsz" 20;
  font-size: var(--text-md);
  font-weight: 500;
  color: var(--fg);
}

.docs-sidebar__sigil {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.06em;
  color: var(--fg-3);
  padding: 2px 6px;
  border: 1px solid var(--rule);
  border-radius: 2px;
}

.sidebar-group { margin-bottom: var(--sp-3); }

.sidebar-group__label {
  display: block;
  padding: var(--sp-4) var(--sp-5) var(--sp-2);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--fg-3);
}

.sidebar-link {
  display: grid;
  grid-template-columns: 26px 1fr;
  align-items: baseline;
  gap: var(--sp-2);
  padding: var(--sp-2) var(--sp-5);
  font-family: var(--font-sans);
  font-size: var(--text-sm);
  font-weight: 400;
  color: var(--fg-2);
  text-decoration: none;
  transition: color 180ms cubic-bezier(0.16, 1, 0.3, 1);
}

.sidebar-link__num {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--fg-3);
  letter-spacing: 0.04em;
}

.sidebar-link__label { line-height: 1.4; }

.sidebar-link:hover,
.sidebar-link:focus-visible { color: var(--fg); }
.sidebar-link:hover .sidebar-link__num,
.sidebar-link:focus-visible .sidebar-link__num { color: var(--fg-2); }

/* Active — colour + breathing pulse on the number */
.sidebar-link--active {
  color: var(--accent);
  font-weight: 500;
}
.sidebar-link--active .sidebar-link__num {
  color: var(--accent);
  animation: sidebar-pulse 2.4s ease-in-out infinite;
}

@keyframes sidebar-pulse {
  0%, 100% { opacity: 1; }
  50%      { opacity: 0.5; }
}

/* ── Main content ──────────────────────────────────────────────────────── */
.docs-content {
  grid-column: 2;
  grid-row: 2;
  padding: var(--sp-7) clamp(var(--sp-5), 4vw, var(--sp-7)) var(--sp-9);
  min-width: 0;
  max-width: 72ch;
}

.docs-content .prose,
.docs-content p,
.docs-content li {
  font-family: var(--font-sans);
  font-size: var(--text-md);
  line-height: 1.7;
  color: var(--fg);
}

.docs-content h1 {
  font-family: var(--font-serif);
  font-variation-settings: "opsz" 48;
  font-size: clamp(2rem, 4vw, 2.66rem);
  font-weight: 500;
  letter-spacing: -0.015em;
  margin: 0 0 var(--sp-5);
}

.docs-content h2 {
  font-family: var(--font-sans);
  font-size: var(--text-xl);
  font-weight: 600;
  margin-top: var(--sp-8);
  margin-bottom: var(--sp-3);
  padding-bottom: var(--sp-2);
  border-bottom: 1px solid var(--rule);
  position: relative;
}

.docs-content h2::before {
  content: '§';
  position: absolute;
  left: -1.4em;
  top: 0.05em;
  font-family: var(--font-mono);
  font-size: 0.7em;
  color: var(--fg-3);
  font-weight: 400;
}

.docs-content h3 {
  font-family: var(--font-sans);
  font-size: var(--text-lg);
  font-weight: 600;
  margin-top: var(--sp-6);
  margin-bottom: var(--sp-2);
}

/* Doc page chapter prefix above the h1 */
.docs-content__chapter {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--fg-3);
  margin: 0 0 var(--sp-3);
  display: flex;
  align-items: baseline;
  gap: var(--sp-3);
}

.docs-content__chapter-of {
  color: var(--fg-3);
  opacity: 0.7;
}

.docs-content__h1 {
  font-family: var(--font-serif);
  font-variation-settings: "opsz" 60;
  font-size: clamp(2rem, 4.5vw, 3rem);
  font-weight: 500;
  letter-spacing: -0.015em;
  line-height: 1.05;
  margin: 0 0 var(--sp-3);
}

.docs-content__desc {
  font-size: var(--text-md);
  color: var(--fg-2);
  margin: 0 0 var(--sp-7);
  max-width: 60ch;
}

/* ── Spec sheet header on project overview ────────────────────────────── */
.docs-spec {
  margin-bottom: var(--sp-7);
}

.docs-spec__sigil {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: var(--text-md);
  font-weight: 500;
  letter-spacing: 0.06em;
  color: var(--fg-3);
  padding: var(--sp-1) var(--sp-3);
  border: 1px solid var(--rule);
  border-radius: 2px;
  margin-bottom: var(--sp-3);
}

.docs-spec__title {
  font-family: var(--font-serif);
  font-variation-settings: "opsz" 72;
  font-size: clamp(2.4rem, 5vw, 3.55rem);
  font-weight: 500;
  letter-spacing: -0.02em;
  line-height: 1;
  margin: 0 0 var(--sp-3);
}

.docs-spec__lede {
  font-size: var(--text-lg);
  line-height: 1.55;
  color: var(--fg);
  max-width: 60ch;
  margin: 0 0 var(--sp-6);
}

.docs-spec__sheet {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
  margin: 0 0 var(--sp-7);
  padding: var(--sp-3) 0;
  border-top: 1px solid var(--rule);
  border-bottom: 1px solid var(--rule);
}

.docs-spec__row {
  display: grid;
  grid-template-columns: 120px 1fr;
  align-items: baseline;
  padding: var(--sp-2) 0;
  font-family: var(--font-mono);
  font-size: var(--text-sm);
}

.docs-spec__row dt {
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--fg-3);
  margin: 0;
}

.docs-spec__row dd {
  color: var(--fg);
  margin: 0;
}

.docs-spec__row dd a {
  color: var(--fg);
  text-decoration: underline;
  text-decoration-color: var(--rule);
  text-underline-offset: 3px;
  transition: text-decoration-color 180ms cubic-bezier(0.16, 1, 0.3, 1),
              color 180ms cubic-bezier(0.16, 1, 0.3, 1);
}
.docs-spec__row dd a:hover { color: var(--accent); text-decoration-color: var(--accent); }

/* ── Quickstart list ───────────────────────────────────────────────────── */
.docs-quickstart {
  margin-top: var(--sp-8);
  padding-top: var(--sp-5);
  border-top: 1px solid var(--rule);
}

.docs-quickstart__label {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--fg-3);
  margin: 0 0 var(--sp-3);
}

.docs-quickstart__list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.docs-quickstart__list li {
  display: grid;
  grid-template-columns: 32px 1fr;
  align-items: baseline;
  gap: var(--sp-3);
  padding: var(--sp-2) 0;
}

.docs-quickstart__num {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--fg-3);
  letter-spacing: 0.04em;
}

.docs-quickstart__list a {
  font-family: var(--font-sans);
  font-size: var(--text-md);
  color: var(--fg);
  text-decoration: none;
  transition: color 180ms cubic-bezier(0.16, 1, 0.3, 1);
}
.docs-quickstart__list a:hover,
.docs-quickstart__list a:focus-visible { color: var(--accent); }

/* ── Prev / next ──────────────────────────────────────────────────────── */
.docs-prev-next {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--sp-5);
  margin-top: var(--sp-9);
  padding-top: var(--sp-5);
  border-top: 1px solid var(--rule);
}

.docs-prev-next a {
  display: flex;
  flex-direction: column;
  gap: 4px;
  font-family: var(--font-sans);
  font-size: var(--text-md);
  color: var(--fg-2);
  text-decoration: none;
  transition: color 180ms cubic-bezier(0.16, 1, 0.3, 1);
}

.docs-prev-next a:hover,
.docs-prev-next a:focus-visible { color: var(--accent); }

.docs-prev-next__dir {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--fg-3);
}

.docs-prev-next__title {
  font-size: var(--text-md);
  font-weight: 500;
  color: var(--fg);
}

.docs-prev-next__right {
  text-align: right;
  margin-left: auto;
}

/* ── On this page (right rail TOC) ────────────────────────────────────── */
.docs-toc {
  grid-column: 3;
  grid-row: 2;
  padding: var(--sp-7) var(--sp-4) var(--sp-7);
  position: sticky;
  top: 56px;
  align-self: start;
  max-height: calc(100dvh - 56px);
  overflow-y: auto;
}

.docs-toc__label {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--fg-3);
  margin: 0 0 var(--sp-3);
}

.docs-toc__list {
  list-style: none;
  padding: 0;
  margin: 0;
  border-left: 1px solid var(--rule);
}

.docs-toc__list li { line-height: 1; }

.docs-toc__list a {
  display: block;
  padding: var(--sp-2) var(--sp-3);
  font-family: var(--font-sans);
  font-size: var(--text-xs);
  color: var(--fg-3);
  text-decoration: none;
  border-left: 1px solid transparent;
  margin-left: -1px;
  transition: color 180ms cubic-bezier(0.16, 1, 0.3, 1),
              border-color 180ms cubic-bezier(0.16, 1, 0.3, 1);
}
.docs-toc__list a:hover,
.docs-toc__list a:focus-visible {
  color: var(--accent);
  border-left-color: var(--accent);
}

/* ── Projects index ────────────────────────────────────────────────────── */
.projects-index {
  max-width: 78ch;
  margin: 0 auto;
  padding: clamp(3rem, 7vw, 5rem) clamp(1.25rem, 4vw, 2rem) var(--sp-9);
}

.projects-index__head {
  margin-bottom: var(--sp-8);
}

.projects-index__kicker {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--fg-3);
  margin: 0 0 var(--sp-4);
}

.projects-index h1 {
  font-family: var(--font-serif);
  font-variation-settings: "opsz" 60;
  font-size: clamp(2.4rem, 6vw, 4rem);
  font-weight: 500;
  letter-spacing: -0.02em;
  line-height: 1;
  margin: 0 0 var(--sp-4);
}

.projects-index__desc {
  font-size: var(--text-lg);
  color: var(--fg-2);
  margin: 0;
  max-width: 60ch;
  line-height: 1.5;
}

.projects-grid {
  list-style: none;
  padding: 0;
  margin: 0;
  counter-reset: project;
}

.project-card {
  border-bottom: 1px solid var(--rule);
  counter-increment: project;
}
.project-card:last-child { border-bottom: none; }

.project-card__link {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: start;
  gap: var(--sp-3) var(--sp-5);
  padding: var(--sp-5) 0;
  text-decoration: none;
  color: var(--fg);
  position: relative;
  transition: padding-left 220ms cubic-bezier(0.16, 1, 0.3, 1);
}
.project-card__link:hover,
.project-card__link:focus-visible {
  padding-left: var(--sp-3);
}

/* Hue accent that appears on hover */
.project-card__link::before {
  content: '';
  position: absolute;
  left: 0;
  top: var(--sp-5);
  bottom: var(--sp-5);
  width: 2px;
  background: var(--hue-default);
  transform: scaleY(0);
  transform-origin: top;
  transition: transform 220ms cubic-bezier(0.16, 1, 0.3, 1);
}
.project-card[data-hue="oss"]      .project-card__link::before { background: var(--hue-oss); }
.project-card[data-hue="ml"]       .project-card__link::before { background: var(--hue-ml); }
.project-card[data-hue="sec"]      .project-card__link::before { background: var(--hue-sec); }
.project-card[data-hue="robo"]     .project-card__link::before { background: var(--hue-robo); }
.project-card[data-hue="net"]      .project-card__link::before { background: var(--hue-net); }
.project-card[data-hue="research"] .project-card__link::before { background: var(--hue-research); }

.project-card__link:hover::before,
.project-card__link:focus-visible::before { transform: scaleY(1); }

.project-card__sigil {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 500;
  letter-spacing: 0.06em;
  color: var(--fg-3);
  padding: 4px 8px;
  border: 1px solid var(--rule);
  border-radius: 2px;
  white-space: nowrap;
  align-self: start;
  margin-top: 4px;
}

.project-card__body {
  min-width: 0;
}

.project-card__title {
  font-family: var(--font-serif);
  font-variation-settings: "opsz" 24;
  font-size: var(--text-xl);
  font-weight: 500;
  line-height: 1.2;
  margin: 0 0 var(--sp-2);
  color: var(--fg);
  transition: color 220ms cubic-bezier(0.16, 1, 0.3, 1);
}
.project-card__link:hover .project-card__title,
.project-card__link:focus-visible .project-card__title { color: var(--accent); }

.project-card__desc {
  font-size: var(--text-sm);
  color: var(--fg-2);
  line-height: 1.55;
  margin: 0 0 var(--sp-3);
  max-width: 56ch;
}

.project-card__meta {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.04em;
  color: var(--fg-3);
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-2);
}

.project-card__cat {
  text-transform: uppercase;
  color: var(--fg-2);
}

.project-card__arrow {
  font-family: var(--font-mono);
  font-size: var(--text-md);
  color: var(--fg-3);
  align-self: center;
  transition: transform 220ms cubic-bezier(0.16, 1, 0.3, 1),
              color 220ms cubic-bezier(0.16, 1, 0.3, 1);
}
.project-card__link:hover .project-card__arrow,
.project-card__link:focus-visible .project-card__arrow {
  transform: translateX(4px);
  color: var(--accent);
}

.projects-grid__empty {
  text-align: left;
  padding: var(--sp-7) 0;
  border-top: 1px solid var(--rule);
  border-bottom: 1px solid var(--rule);
}
.projects-grid__empty p {
  font-family: var(--font-serif);
  font-size: var(--text-xl);
  color: var(--fg);
  margin: 0 0 var(--sp-2);
}
.projects-grid__empty-sub {
  font-family: var(--font-sans) !important;
  font-size: var(--text-sm) !important;
  color: var(--fg-3) !important;
}

/* ── Responsive ────────────────────────────────────────────────────────── */
@media (max-width: 1024px) {
  /* Drop the right TOC rail; sidebar + content stay */
  .docs-layout { grid-template-columns: 240px minmax(0, 1fr); }
  .docs-toc { display: none; }
}

@media (max-width: 768px) {
  .docs-layout { grid-template-columns: 1fr; }
  .docs-sidebar {
    grid-column: 1;
    grid-row: 2;
    position: static;
    max-height: none;
    border-right: none;
    border-bottom: 1px solid var(--rule);
    padding: var(--sp-3) 0;
  }
  .docs-content {
    grid-column: 1;
    grid-row: 3;
    padding: var(--sp-5) var(--sp-4) var(--sp-8);
  }
  /* Hide the section glyph on h2 — no room in margin */
  .docs-content h2::before { display: none; }
}

@media (max-width: 540px) {
  .project-card__link { grid-template-columns: auto 1fr; gap: var(--sp-3); }
  .project-card__arrow { display: none; }
}