/* =========================================================
   Palette + base - modeled on transformer-explainer:
   warm off-white, deep ink, accent yellows / blues / red.
   ========================================================= */
:root {
  --bg: #faf7f2;
  --bg-soft: #f3eee5;
  --ink: #1a1a1a;
  --ink-soft: #4a4a4a;
  --rule: #d8cfbf;

  --tok: #e9e3d4;
  --tok-stroke: #b9af96;

  --blk: #b8d8e8;
  --blk-stroke: #5b8aa3;

  --pic: #f6c453;
  --pic-stroke: #b08218;

  --kv: #cfe6cf;
  --kv-stroke: #5e9c5e;

  --recomp: #ef6f4a;
  --recomp-stroke: #a83b1b;

  --gap: rgba(239, 111, 74, 0.18);
  --gap-stroke: #ef6f4a;

  --hash-a: #4a6fa5;
  --hash-b: #b85c8e;

  --link: #2a5a9c;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: "Inter", "Helvetica Neue", system-ui, sans-serif;
  font-size: 16px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

code, .mono {
  font-family: "JetBrains Mono", "SF Mono", Menlo, Consolas, monospace;
  font-size: 0.92em;
}

a { color: var(--link); }

/* =========================================================
   Hero
   ========================================================= */
.hero {
  border-bottom: 1px solid var(--rule);
  padding: 6rem 1.5rem 4rem;
  background:
    radial-gradient(1200px 600px at 80% -10%, #f6e3a6 0%, transparent 60%),
    radial-gradient(800px 400px at 0% 110%, #cfe6e8 0%, transparent 60%),
    var(--bg);
}

.hero-inner {
  max-width: 1100px;
  margin: 0 auto;
}

.eyebrow {
  letter-spacing: 0.18em;
  text-transform: uppercase;
  font-size: 0.72rem;
  color: var(--ink-soft);
  margin: 0 0 1rem;
}

h1 {
  font-size: clamp(3rem, 8vw, 6rem);
  line-height: 0.95;
  letter-spacing: -0.03em;
  margin: 0 0 1.5rem;
  font-weight: 800;
}

h1 .thin {
  font-weight: 200;
  font-style: italic;
  color: var(--ink-soft);
}

.lede {
  max-width: 56ch;
  font-size: 1.15rem;
  color: var(--ink-soft);
  margin: 0 0 2rem;
}

.lede em {
  font-style: italic;
  color: var(--ink);
}

.legend {
  display: flex;
  flex-wrap: wrap;
  gap: 1.25rem;
  font-size: 0.85rem;
  color: var(--ink-soft);
}

.legend .dot {
  display: inline-block;
  width: 12px;
  height: 12px;
  border-radius: 3px;
  margin-right: 0.4rem;
  vertical-align: middle;
  border: 1px solid var(--ink);
}

.legend .tok    { background: var(--tok); border-color: var(--tok-stroke); }
.legend .blk    { background: var(--blk); border-color: var(--blk-stroke); }
.legend .pic    { background: var(--pic); border-color: var(--pic-stroke); }
.legend .kv     { background: var(--kv);  border-color: var(--kv-stroke); }
.legend .recomp { background: var(--recomp); border-color: var(--recomp-stroke); }

/* =========================================================
   TOC
   ========================================================= */
.toc {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(250, 247, 242, 0.92);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--rule);
}

.toc ol {
  display: flex;
  flex-wrap: wrap;
  gap: 1.25rem;
  list-style: none;
  margin: 0;
  padding: 0.85rem 1.5rem;
  max-width: 1100px;
  margin: 0 auto;
  font-size: 0.83rem;
}

.toc a {
  color: var(--ink-soft);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  padding-bottom: 1px;
}

.toc a:hover {
  color: var(--ink);
  border-bottom-color: var(--ink);
}

.toc a.cross {
  color: var(--link);
  font-style: italic;
}

.eyebrow a {
  color: inherit;
  text-decoration: none;
  border-bottom: 1px dotted var(--ink-soft);
}

.eyebrow a:hover {
  color: var(--ink);
  border-bottom-color: var(--ink);
}

/* =========================================================
   vLLM-tour-only viz helpers
   ========================================================= */
.lane-label {
  font-family: "JetBrains Mono", monospace;
  font-size: 11px;
  fill: var(--ink-soft);
}

.lane-bg {
  fill: var(--bg-soft);
  stroke: var(--rule);
  stroke-width: 1;
}

.lane-bg.done {
  fill: #fff;
  stroke-dasharray: 3 3;
}

.draft-rect {
  fill: #ffe9c8;
  stroke: var(--pic-stroke);
  stroke-width: 1.2;
}

.draft-rect.rejected {
  fill: #fde0d4;
  stroke: var(--recomp-stroke);
}

.target-rect {
  fill: var(--kv);
  stroke: var(--kv-stroke);
  stroke-width: 1.5;
}

.cache-hit-rect {
  fill: var(--kv);
  stroke: var(--kv-stroke);
  stroke-width: 1.5;
}

.block-table-row {
  fill: #fff;
  stroke: var(--rule);
}

.block-table-row.used {
  fill: var(--bg-soft);
}

.physical-pool-cell {
  fill: #fff;
  stroke: var(--rule);
}

.physical-pool-cell.allocated {
  fill: var(--blk);
  stroke: var(--blk-stroke);
}

.physical-pool-cell.allocated.shared {
  fill: var(--kv);
  stroke: var(--kv-stroke);
}

.connector {
  stroke: var(--ink-soft);
  stroke-width: 1;
  fill: none;
  opacity: 0.45;
}

/* =========================================================
   Sections
   ========================================================= */
.step {
  max-width: 1100px;
  margin: 0 auto;
  padding: 5rem 1.5rem;
  border-bottom: 1px solid var(--rule);
}

.step-head {
  margin-bottom: 2.5rem;
  max-width: 70ch;
}

.step h2 {
  font-size: clamp(1.6rem, 3vw, 2.4rem);
  line-height: 1.15;
  letter-spacing: -0.01em;
  margin: 0.5rem 0 1rem;
  font-weight: 700;
}

.step h2 em {
  font-style: italic;
  color: var(--recomp);
}

.ribbon {
  display: inline-block;
  font-size: 0.7rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  background: var(--ink);
  color: var(--bg);
  padding: 0.25rem 0.55rem;
  border-radius: 2px;
}

.claim {
  font-size: 0.95rem;
  color: var(--ink-soft);
  margin: 0.75rem 0 0;
}

.claim code {
  background: var(--bg-soft);
  padding: 1px 5px;
  border-radius: 3px;
}

.explainer {
  max-width: 65ch;
  margin-bottom: 2rem;
  color: var(--ink-soft);
}

.explainer code,
.explainer strong {
  color: var(--ink);
}

.explainer code {
  background: var(--bg-soft);
  padding: 1px 5px;
  border-radius: 3px;
}

/* =========================================================
   Concepts grid
   ========================================================= */
.concepts-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.5rem;
}

.concept {
  background: #fff;
  border: 1px solid var(--rule);
  border-radius: 6px;
  padding: 1.25rem;
}

.concept h3 {
  margin: 0 0 0.5rem;
  font-size: 1.05rem;
  letter-spacing: 0.01em;
}

.concept p {
  font-size: 0.88rem;
  color: var(--ink-soft);
  margin: 0 0 1rem;
}

.concept[data-term] {
  transition: transform 120ms ease;
}

.concept[data-term]:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 18px rgba(0, 0, 0, 0.06);
}

/* =========================================================
   Visualization wrappers
   ========================================================= */
.viz-wrap {
  background: #fff;
  border: 1px solid var(--rule);
  border-radius: 8px;
  padding: 1.5rem;
}

.viz-wrap svg {
  display: block;
  width: 100%;
  height: auto;
  overflow: visible;
}

.controls {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
  margin-top: 1rem;
  padding-top: 1rem;
  border-top: 1px dashed var(--rule);
}

.controls button {
  background: var(--ink);
  color: var(--bg);
  border: 0;
  padding: 0.5rem 0.9rem;
  border-radius: 4px;
  font-family: inherit;
  font-size: 0.85rem;
  cursor: pointer;
  transition: background 100ms;
}

.controls button:hover {
  background: var(--recomp);
}

.controls label {
  font-size: 0.85rem;
  color: var(--ink-soft);
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
}

.controls input[type="range"] {
  width: 200px;
}

.state {
  margin-top: 1rem;
  padding: 0.85rem 1rem;
  background: var(--bg-soft);
  border-left: 3px solid var(--ink);
  border-radius: 2px;
  font-family: "JetBrains Mono", monospace;
  font-size: 0.82rem;
  color: var(--ink);
  white-space: pre-wrap;
}

/* =========================================================
   SVG helpers - token + block visuals
   ========================================================= */
.tok-rect {
  fill: var(--tok);
  stroke: var(--tok-stroke);
  stroke-width: 1;
}

.blk-rect {
  fill: var(--blk);
  stroke: var(--blk-stroke);
  stroke-width: 1.5;
}

.pic-rect {
  fill: var(--pic);
  stroke: var(--pic-stroke);
  stroke-width: 1.5;
}

.kv-rect {
  fill: var(--kv);
  stroke: var(--kv-stroke);
  stroke-width: 1.5;
}

.recomp-rect {
  fill: var(--recomp);
  stroke: var(--recomp-stroke);
  stroke-width: 1.5;
}

.gap-rect {
  fill: var(--gap);
  stroke: var(--gap-stroke);
  stroke-width: 1.5;
  stroke-dasharray: 4 3;
}

.lbl {
  font-family: "JetBrains Mono", monospace;
  font-size: 11px;
  fill: var(--ink);
}

.lbl-soft {
  fill: var(--ink-soft);
}

.lbl-tiny {
  font-size: 9px;
}

.hash-line {
  stroke: var(--hash-a);
  stroke-width: 1.5;
  fill: none;
  marker-end: url(#arrow);
}

.hash-line.cut {
  stroke: var(--recomp);
  stroke-dasharray: 4 3;
}

.hash-pill {
  fill: #fff;
  stroke: var(--hash-a);
  stroke-width: 1.2;
}

.hash-pill.match-a { stroke: var(--hash-a); }
.hash-pill.match-b { stroke: var(--hash-b); }

.section-divider {
  stroke: var(--rule);
  stroke-width: 1;
  stroke-dasharray: 2 4;
}

.flash {
  animation: flash 600ms ease;
}

@keyframes flash {
  0%   { filter: brightness(1.4) drop-shadow(0 0 8px var(--recomp)); }
  100% { filter: none; }
}

footer {
  max-width: 1100px;
  margin: 0 auto;
  padding: 3rem 1.5rem 4rem;
  color: var(--ink-soft);
  font-size: 0.85rem;
}

footer code {
  background: var(--bg-soft);
  padding: 1px 5px;
  border-radius: 3px;
}