/* Zero-Knowledge has Three Algorithms
   ===================================
   Editorial-style long-form design. Warm-dark palette, serif body,
   single accent color. Mobile-first; desktop adds wider columns and
   margin sidenotes.

   Visual rules:
   - Body text is the default. Cards are reserved for experiments
     and data-heavy panels, not bullet lists.
   - Single warm accent (#e07a3c) for emphasis. Code spans use a
     muted teal (#5c9ea3). No blue/purple AI palette.
   - 680px reading column on desktop; full width on mobile.
   - Triple-dot dingbat between top-level sections, not horizontal
     rules.
*/

:root {
  /* Palette */
  --bg:          #15110f;
  --bg-soft:     #1c1814;
  --bg-card:     #221c17;
  --fg:          #f4ede1;
  --fg-dim:      #b3a999;
  --fg-faint:    #6f6657;
  --accent:      #e07a3c;
  --accent-soft: rgba(224, 122, 60, 0.12);
  --code:        #6ab0b5;
  --rule:        #2d251f;
  --ok:          #88c479;
  --bad:         #d96a6a;
  --warn:        #e0b063;

  /* Typography */
  --font-body:   "Source Serif 4", "Source Serif Pro", Charter, Georgia, "Iowan Old Style", serif;
  --font-head:   Inter, -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
  --font-mono:   "JetBrains Mono", "Fira Code", ui-monospace, "SF Mono", Menlo, monospace;

  /* Sizes */
  --column:      680px;
  --column-wide: 960px;
  --gutter:      1.25rem;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: var(--font-body);
  font-size: 18px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

::selection { background: var(--accent); color: var(--bg); }

a { color: var(--accent); text-decoration: none; border-bottom: 1px solid currentColor; }
a:hover { color: var(--fg); }

code, pre, kbd { font-family: var(--font-mono); }
code { color: var(--code); font-size: 0.92em; font-feature-settings: "calt" 0; }

/* ---------- Skip-to-content ---------- */

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--accent);
  color: var(--bg);
  padding: 0.6rem 1rem;
  font-family: var(--font-head);
  font-weight: 600;
  text-decoration: none;
  z-index: 100;
}
.skip-link:focus { left: 0; outline: 2px solid var(--fg); outline-offset: 2px; }

/* ---------- Site nav ---------- */

.site-nav {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(21, 17, 15, 0.92);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--rule);
}

.site-nav-inner {
  max-width: var(--column-wide);
  margin: 0 auto;
  padding: 0.85rem var(--gutter);
  display: flex;
  align-items: center;
  gap: 1.25rem;
  font-family: var(--font-head);
}

.site-nav-brand {
  font-weight: 600;
  letter-spacing: -0.01em;
  color: var(--fg);
  border-bottom: none;
  font-size: 0.92rem;
}
.site-nav-brand:hover { color: var(--accent); }
.site-nav-brand strong { color: var(--accent); font-weight: 600; }

.site-nav-links {
  display: flex;
  gap: 1.1rem;
  margin-left: auto;
  flex-wrap: wrap;
}

.site-nav-links a {
  color: var(--fg-dim);
  font-size: 0.86rem;
  border-bottom: none;
  padding: 0.15rem 0;
  border-bottom: 2px solid transparent;
}
.site-nav-links a:hover { color: var(--fg); }
.site-nav-links a[aria-current="page"] {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

.nav-toggle {
  display: none;
  background: transparent;
  border: 1px solid var(--rule);
  color: var(--fg);
  padding: 0.3rem 0.6rem;
  border-radius: 3px;
  font-family: var(--font-head);
  font-size: 0.85rem;
  cursor: pointer;
  margin-left: auto;
}

/* Mobile nav */
@media (max-width: 640px) {
  .nav-toggle { display: block; }
  .site-nav-links {
    display: none;
    flex-direction: column;
    width: 100%;
    margin-left: 0;
    margin-top: 0.85rem;
    padding-top: 0.85rem;
    border-top: 1px solid var(--rule);
    gap: 0.85rem;
  }
  .site-nav-inner.open { flex-wrap: wrap; }
  .site-nav-inner.open .site-nav-links { display: flex; }
}

/* ---------- Page wrapper ---------- */

main.page {
  max-width: var(--column);
  margin: 0 auto;
  padding: 3rem var(--gutter) 4rem;
}

main.page-wide {
  max-width: var(--column-wide);
}

/* ---------- Headers (article-style) ---------- */

h1, h2, h3, h4 {
  font-family: var(--font-head);
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: -0.02em;
  margin: 0;
}

h1 {
  font-size: clamp(2.2rem, 5.5vw, 3.4rem);
  margin-top: 0.5rem;
  margin-bottom: 1rem;
}

h2 {
  font-size: clamp(1.55rem, 3.5vw, 2rem);
  margin-top: 3.5rem;
  margin-bottom: 1rem;
  letter-spacing: -0.015em;
}

h3 {
  font-size: 1.2rem;
  margin-top: 2.25rem;
  margin-bottom: 0.6rem;
  color: var(--fg);
}

h4 {
  font-size: 0.95rem;
  font-family: var(--font-head);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--fg-dim);
  margin-top: 1.5rem;
  margin-bottom: 0.6rem;
}

p { margin: 0 0 1.1em; }

p + h2, ul + h2, ol + h2, pre + h2, .card + h2 { margin-top: 4rem; }

/* Section break dingbat instead of <hr>. Use <div class="rule">...</div>. */
.rule {
  text-align: center;
  margin: 3rem 0;
  color: var(--fg-faint);
  letter-spacing: 1rem;
  font-size: 0.9rem;
  user-select: none;
}
.rule::before { content: "· · ·"; }

/* ---------- Page header / lede ---------- */

.page-header {
  margin-bottom: 2.5rem;
}

.page-header .eyebrow {
  font-family: var(--font-head);
  font-size: 0.78rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.85rem;
}

.lede {
  font-size: 1.2rem;
  line-height: 1.55;
  color: var(--fg);
  margin: 1.5rem 0 1.2rem;
}

.byline {
  font-size: 0.92rem;
  color: var(--fg-dim);
  font-style: italic;
  margin: 0.75rem 0 2rem;
}

/* Drop-cap on the first paragraph of the body section. */
.drop-cap::first-letter {
  font-family: var(--font-head);
  font-weight: 600;
  font-size: 3.6em;
  float: left;
  line-height: 0.88;
  margin: 0.1em 0.08em -0.1em 0;
  color: var(--accent);
}

/* ---------- Lists, naturally typeset ---------- */

ul, ol { padding-left: 1.3em; margin: 0 0 1.2em; }
li { margin-bottom: 0.45em; }
li::marker { color: var(--fg-faint); }

/* The numbered algorithm walkthrough in "how the simulator does it".
   Slightly looser, no card chrome. */
ol.algo li {
  margin-bottom: 0.85em;
  padding-left: 0.4em;
}
ol.algo li strong { color: var(--accent); font-weight: 600; }

/* ---------- Inline code + glossary terms ---------- */

dl.glossary {
  margin: 1.2em 0;
  display: grid;
  grid-template-columns: max-content 1fr;
  gap: 0.4em 1.2em;
  font-size: 0.96em;
}
dl.glossary dt {
  font-family: var(--font-mono);
  color: var(--code);
  font-size: 0.88em;
  align-self: baseline;
  padding-top: 0.15em;
}
dl.glossary dd { margin: 0; color: var(--fg-dim); }
dl.glossary dd code { color: var(--code); background: transparent; padding: 0; }

@media (max-width: 640px) {
  dl.glossary { grid-template-columns: 1fr; gap: 0.15em; }
  dl.glossary dt { padding-top: 0.6em; }
}

/* ---------- Formal-claim block ---------- */

.formal-claim {
  font-family: var(--font-mono);
  font-size: 1.02rem;
  color: var(--fg);
  background: var(--bg-soft);
  border-left: 3px solid var(--accent);
  padding: 1rem 1.25rem;
  margin: 1.5em 0;
  overflow-x: auto;
  line-height: 1.55;
}

/* ---------- Pull-quote / blockquote ---------- */

blockquote {
  border-left: 2px solid var(--accent);
  margin: 1.5em 0;
  padding-left: 1.25em;
  color: var(--fg-dim);
  font-style: italic;
}

/* ---------- Cards (sparingly) ---------- */

.card {
  background: var(--bg-soft);
  border: 1px solid var(--rule);
  border-radius: 4px;
  padding: 1.2rem 1.3rem;
  margin: 1.5em 0;
}

.card-emph {
  border-left: 3px solid var(--accent);
}

/* ---------- Run strip (interactive controls) ---------- */

.run-strip {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.75rem;
  margin: 1.5em 0;
  font-family: var(--font-head);
}

.run-strip label {
  font-size: 0.88rem;
  color: var(--fg-dim);
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
}

.run-strip input[type="number"] {
  background: var(--bg-soft);
  color: var(--fg);
  border: 1px solid var(--rule);
  padding: 0.45rem 0.6rem;
  border-radius: 3px;
  font-family: var(--font-mono);
  font-size: 0.92rem;
  width: 80px;
}

.run-strip input[type="number"]:focus {
  outline: none;
  border-color: var(--accent);
}

.run-strip button {
  background: var(--accent);
  color: var(--bg);
  border: none;
  padding: 0.55rem 1.1rem;
  font-family: var(--font-head);
  font-size: 0.92rem;
  font-weight: 600;
  border-radius: 3px;
  cursor: pointer;
  min-height: 44px;
  transition: background 0.15s, transform 0.05s;
}

.run-strip button:hover:not(:disabled) {
  background: #f59861;
}
.run-strip button:active:not(:disabled) {
  transform: translateY(1px);
}
.run-strip button:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.run-strip button.secondary {
  background: transparent;
  color: var(--accent);
  border: 1px solid var(--accent);
}
.run-strip button.secondary:hover:not(:disabled) {
  background: var(--accent-soft);
}

.run-status {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--fg-dim);
}
.run-status.ok { color: var(--ok); }
.run-status.error { color: var(--bad); }

/* ---------- Verdict tile (hero verdict for an experiment) ---------- */

.verdict-tile {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
  padding: 1.1rem 1.25rem;
  border-radius: 4px;
  background: var(--bg-soft);
  border-left: 3px solid var(--rule);
  margin: 1.25em 0;
}

.verdict-tile .icon {
  width: 26px;
  height: 26px;
  border-radius: 50%;
  background: var(--rule);
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--bg);
  font-weight: 700;
  font-size: 0.95rem;
  margin-top: 0.15rem;
}

.verdict-tile.accept { border-left-color: var(--ok); }
.verdict-tile.accept .icon { background: var(--ok); }
.verdict-tile.accept .icon::after { content: "✓"; }

.verdict-tile.reject { border-left-color: var(--bad); }
.verdict-tile.reject .icon { background: var(--bad); }
.verdict-tile.reject .icon::after { content: "✗"; }

.verdict-headline {
  font-family: var(--font-head);
  font-weight: 600;
  font-size: 1.02rem;
  color: var(--fg);
  margin-bottom: 0.25rem;
}

.verdict-sub {
  font-size: 0.92rem;
  color: var(--fg-dim);
  font-family: var(--font-body);
}
.verdict-sub code { color: var(--code); }

/* ---------- Hex fields + copy buttons ---------- */

.hex-field {
  display: grid;
  grid-template-columns: max-content 1fr auto;
  gap: 0.5rem 1rem;
  padding: 0.55rem 0;
  border-bottom: 1px solid var(--rule);
  align-items: center;
  font-family: var(--font-mono);
  font-size: 0.78rem;
}
.hex-field:last-child { border-bottom: none; }
.hex-field-name { color: var(--fg-dim); white-space: nowrap; }
.hex-field-value { color: var(--fg); word-break: break-all; }

.copy-btn {
  background: transparent;
  border: 1px solid var(--rule);
  color: var(--fg-dim);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  padding: 0.25rem 0.6rem;
  border-radius: 3px;
  cursor: pointer;
  transition: background 0.15s, color 0.15s, border-color 0.15s;
  min-height: 28px;
  white-space: nowrap;
}
.copy-btn:hover {
  background: var(--accent);
  color: var(--bg);
  border-color: var(--accent);
}
.copy-btn.copied {
  background: var(--ok);
  color: var(--bg);
  border-color: var(--ok);
}

@media (max-width: 640px) {
  .hex-field {
    grid-template-columns: 1fr auto;
    gap: 0.25rem 0.5rem;
  }
  .hex-field-name { grid-column: 1 / -1; }
}

/* ---------- Progress bar (worker activity) ---------- */

.progress {
  margin: 1.25em 0;
  padding: 0.85rem 1rem;
  background: var(--bg-soft);
  border-radius: 4px;
  border-left: 2px solid var(--accent);
}
.progress[hidden] { display: none; }
.progress-row {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  margin-bottom: 0.6rem;
}
.progress-phase { color: var(--accent); }
.progress-time { color: var(--fg); font-variant-numeric: tabular-nums; font-weight: 600; }
.progress-bar {
  height: 5px;
  background: var(--bg);
  border-radius: 3px;
  overflow: hidden;
  position: relative;
}
.progress-fill {
  position: absolute;
  top: 0; bottom: 0; left: 0; width: 35%;
  background: linear-gradient(90deg, transparent, var(--accent), transparent);
  animation: indeterminate 1.4s infinite linear;
}
@keyframes indeterminate {
  0%   { transform: translateX(-100%); }
  100% { transform: translateX(370%); }
}
.progress-hint {
  margin-top: 0.5rem;
  font-size: 0.74rem;
  color: var(--fg-faint);
  font-family: var(--font-mono);
}

/* ---------- Stage cards (flow diagram) ---------- */

.flow {
  display: grid;
  grid-template-columns: 1fr auto 1fr auto 1fr auto 1fr;
  gap: 0.5rem;
  margin: 1.5em 0;
  align-items: stretch;
}

.flow-stage {
  background: var(--bg-soft);
  border-radius: 4px;
  border-top: 2px solid var(--rule);
  padding: 0.75rem 0.85rem;
  display: flex;
  flex-direction: column;
  gap: 0.45rem;
  font-family: var(--font-head);
  font-size: 0.86rem;
  position: relative;
  transition: border-top-color 0.2s, background 0.2s;
}

.flow-stage.active {
  border-top-color: var(--warn);
  background: rgba(224, 176, 99, 0.07);
  animation: flow-pulse 1.2s infinite ease-in-out;
}
.flow-stage.done { border-top-color: var(--ok); }
.flow-stage.done::after {
  content: "✓"; position: absolute; top: 0.55rem; right: 0.7rem;
  color: var(--ok); font-weight: 700; font-size: 0.95rem;
}

@keyframes flow-pulse {
  0%, 100% { box-shadow: 0 0 0 0 rgba(224, 176, 99, 0); }
  50%      { box-shadow: 0 0 0 4px rgba(224, 176, 99, 0.15); }
}

.flow-stage-head { display: flex; align-items: center; gap: 0.55rem; }
.flow-stage-num {
  width: 22px; height: 22px;
  border-radius: 50%;
  background: var(--accent);
  color: var(--bg);
  font-weight: 700;
  font-size: 0.76rem;
  display: flex; align-items: center; justify-content: center;
  font-family: var(--font-mono);
  flex-shrink: 0;
}
.flow-stage-name { font-weight: 600; color: var(--fg); }
.flow-stage-detail {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--fg-dim);
  line-height: 1.45;
  word-break: break-word;
}
.flow-stage-detail code { color: var(--code); background: transparent; padding: 0; }
.flow-stage-out {
  margin-top: auto;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--accent);
  padding-top: 0.4rem;
  border-top: 1px dashed var(--rule);
}
.flow-stage-timing {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--ok);
  min-height: 1em;
}
.flow-stage-timing:empty { display: none; }

.flow-arrow {
  display: flex; align-items: center; justify-content: center;
  color: var(--fg-faint);
  font-size: 1.2rem;
}

@media (max-width: 780px) {
  .flow { grid-template-columns: 1fr; }
  .flow-arrow { transform: rotate(90deg); padding: 0.15rem 0; }
}

/* ---------- Stats strip ---------- */

.stats {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin: 1.25em 0;
  align-items: center;
}
.stats[hidden] { display: none; }

.stat {
  background: var(--bg-soft);
  padding: 0.5rem 0.85rem;
  border-radius: 4px;
  border-left: 2px solid var(--accent);
  display: flex;
  flex-direction: column;
  gap: 0.05rem;
  min-width: 130px;
}
.stat-label {
  font-family: var(--font-head);
  font-size: 0.68rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--fg-dim);
}
.stat-value {
  font-family: var(--font-mono);
  font-size: 0.95rem;
  color: var(--fg);
  font-weight: 600;
  font-variant-numeric: tabular-nums;
}

.stats-reset {
  margin-left: auto;
  background: transparent;
  color: var(--fg-dim);
  border: 1px solid var(--rule);
  padding: 0.4rem 0.85rem;
  font-family: var(--font-head);
  font-size: 0.78rem;
  border-radius: 3px;
  cursor: pointer;
}
.stats-reset:hover { background: var(--bad); color: var(--bg); border-color: var(--bad); }

/* ---------- Tables ---------- */

table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5em 0;
  font-size: 0.92em;
}
table th, table td {
  padding: 0.55rem 0.75rem;
  text-align: left;
  border-bottom: 1px solid var(--rule);
  vertical-align: top;
}
table th {
  font-family: var(--font-head);
  font-weight: 600;
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--fg-dim);
}
table td.num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  color: var(--accent);
  white-space: nowrap;
}
table tr.highlight-row {
  background: var(--accent-soft);
}
table .ok-cell  { color: var(--ok); }
table .bad-cell { color: var(--bad); }

/* ---------- Code blocks ---------- */

pre {
  background: var(--bg-soft);
  border-radius: 4px;
  padding: 1rem 1.15rem;
  margin: 1.25em 0;
  overflow-x: auto;
  font-size: 0.82rem;
  line-height: 1.55;
  border-left: 2px solid var(--code);
}
pre code { color: var(--fg); background: transparent; padding: 0; }

/* ---------- Hero card on the landing page ---------- */

.hero {
  padding: 4rem var(--gutter) 3rem;
  text-align: left;
  max-width: var(--column);
  margin: 0 auto;
}

.hero h1 {
  font-size: clamp(2.5rem, 7vw, 4rem);
  letter-spacing: -0.025em;
  margin-bottom: 0.5rem;
  line-height: 1.05;
}
.hero h1 .accent { color: var(--accent); }

.hero-deck {
  font-size: clamp(1.05rem, 2.4vw, 1.25rem);
  color: var(--fg-dim);
  max-width: 540px;
  line-height: 1.55;
  margin: 1.25rem 0 2rem;
}

.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 1.25rem;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--fg-faint);
  margin-top: 2.5rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--rule);
}

/* ---------- Section cards (landing page navigation) ---------- */

.toc-cards {
  display: grid;
  gap: 1rem;
  grid-template-columns: 1fr;
  margin: 2.5em 0;
}

@media (min-width: 720px) {
  .toc-cards { grid-template-columns: 1fr 1fr; }
}

.toc-card {
  background: var(--bg-soft);
  border: 1px solid var(--rule);
  border-radius: 4px;
  padding: 1.5rem 1.5rem;
  text-decoration: none;
  border-bottom: 1px solid var(--rule);
  color: var(--fg);
  transition: border-color 0.15s, background 0.15s, transform 0.1s;
  display: block;
}
.toc-card:hover {
  border-color: var(--accent);
  background: rgba(224, 122, 60, 0.04);
  transform: translateY(-1px);
  color: var(--fg);
}
.toc-card .toc-card-number {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--accent);
  letter-spacing: 0.1em;
}
.toc-card .toc-card-title {
  font-family: var(--font-head);
  font-size: 1.15rem;
  font-weight: 600;
  margin: 0.4rem 0 0.5rem;
  letter-spacing: -0.01em;
}
.toc-card .toc-card-desc {
  font-size: 0.95rem;
  color: var(--fg-dim);
  line-height: 1.5;
}

/* ---------- Footer ---------- */

footer {
  border-top: 1px solid var(--rule);
  margin-top: 5rem;
  padding: 2.5rem var(--gutter);
  font-size: 0.86rem;
  color: var(--fg-dim);
}

footer .footer-inner {
  max-width: var(--column);
  margin: 0 auto;
}

footer dl {
  display: grid;
  grid-template-columns: max-content 1fr;
  gap: 0.4rem 1.5rem;
  margin: 1.5rem 0 0;
  font-size: 0.82rem;
  padding-top: 1rem;
  border-top: 1px solid var(--rule);
}
footer dt {
  font-family: var(--font-head);
  font-weight: 600;
  font-size: 0.74rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--accent);
  align-self: baseline;
  padding-top: 0.18rem;
}
footer dd { margin: 0; color: var(--fg-dim); line-height: 1.55; }
footer code { color: var(--code); background: transparent; padding: 0; font-size: 0.88em; }

@media (max-width: 640px) {
  footer dl { grid-template-columns: 1fr; gap: 0.15rem; }
  footer dt { margin-top: 0.55rem; }
}

/* ---------- Print ---------- */

@media print {
  html, body { background: #fff !important; color: #000 !important; }
  body * { color: #000 !important; background: transparent !important; }
  .site-nav, .run-strip, .skip-link, .stats, .copy-btn, .nav-toggle { display: none !important; }
  details { display: block !important; }
  summary { display: none !important; }
  a[href^="http"]::after {
    content: " [" attr(href) "]";
    font-size: 9pt;
    color: #555 !important;
    word-break: break-all;
  }
}