/* convergence.css — scoped styles for the ML robot post.
 * Site-wide post conventions (title block, .post-intro, .post-conclusion)
 * live in shallow-learning/blog-extras.css. Do NOT redeclare them here.
 *
 * Two scopes used in this file:
 *   .robot-fig / .rule-box / [class^="rb-"] — small inline diagram styles
 *   .ml-widget                                — the live gradient-descent widget
 *
 * Both stay narrow enough to fit the 72ch post column.
 */

/* ---------- Robot SVG figure ---------- */

figure.robot-fig {
  margin: 1.5rem auto;
  max-width: 480px;
  text-align: center;
  color: var(--ink);
}

figure.robot-fig svg {
  display: block;
  width: 100%;
  height: auto;
}

text.rb-input {
  font-family: 'JetBrains Mono', monospace;
  font-size: 16px;
  font-weight: 700;
  letter-spacing: 0.08em;
  fill: var(--warm);
}

text.rb-output {
  font-family: 'JetBrains Mono', monospace;
  font-size: 16px;
  font-weight: 700;
  letter-spacing: 0.08em;
  fill: var(--accent);
}

text.rb-rule {
  font-family: 'JetBrains Mono', monospace;
  font-size: 18px;
  font-weight: 700;
  letter-spacing: 0.22em;
  fill: var(--accent);
}

text.rb-formula {
  font-family: 'Fraunces', Georgia, serif;
  font-style: italic;
  font-size: 38px;
  font-weight: 500;
  fill: var(--ink);
}

/* ---------- Side-by-side comparison tables (programming vs ML) ---------- */

.compare-tables {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin: 1.75rem 0;
}

.compare-tables .compare-col {
  border: 1px solid var(--rule-soft);
  border-radius: 4px;
  background: var(--card);
  padding: 0.9rem 1rem 0.6rem;
}

.compare-tables .compare-label {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--muted);
  margin-bottom: 0.5rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--rule-soft);
}

.compare-tables .compare-tbl {
  width: 100%;
  margin: 0;
  font-size: 0.95rem;
  font-variant-numeric: tabular-nums;
}

.compare-tables .compare-tbl th,
.compare-tables .compare-tbl td {
  padding: 0.4rem 0.6rem;
  text-align: center;
  border-bottom: 1px solid rgba(94, 117, 101, 0.2);
}

.compare-tables .compare-tbl th {
  font-family: 'JetBrains Mono', monospace;
  font-weight: 500;
  font-size: 0.8rem;
  color: var(--muted);
  text-transform: lowercase;
}

@media (max-width: 540px) {
  .compare-tables { grid-template-columns: 1fr; gap: 1rem; }
}

/* ---------- Four ingredients list (the crux of the post) ---------- */

ol.ingredients {
  list-style: none;
  padding: 0;
  margin: 1.5rem 0 2rem;
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
}

ol.ingredients > li {
  display: grid;
  grid-template-columns: 3.25rem 1fr;
  gap: 1rem;
  align-items: start;
  padding: 1rem 1.1rem;
  border: 1px solid var(--rule-soft);
  border-left: 3px solid var(--accent);
  border-radius: 4px;
  background: var(--bg);
}

ol.ingredients .ing-num {
  font-family: 'Fraunces', Georgia, serif;
  font-weight: 400;
  font-size: 2.4rem;
  line-height: 1;
  color: var(--accent);
  text-align: center;
  font-variant-numeric: lining-nums;
}

ol.ingredients .ing-body { min-width: 0; }

ol.ingredients .ing-name {
  font-family: 'Fraunces', Georgia, serif;
  font-weight: 500;
  font-size: 1.35rem;
  line-height: 1.2;
  color: var(--ink);
  margin-bottom: 0.3rem;
}

ol.ingredients .ing-body p {
  margin: 0;
  line-height: 1.55;
}

@media (max-width: 540px) {
  ol.ingredients > li {
    grid-template-columns: 2.4rem 1fr;
    padding: 0.85rem 0.9rem;
  }
  ol.ingredients .ing-num { font-size: 2rem; }
  ol.ingredients .ing-name { font-size: 1.2rem; }
}

/* ---------- <details> under-the-hood blocks ---------- */

main details {
  margin: 1rem 0 1.5rem;
  padding: 0.6rem 1rem;
  border: 1px solid var(--rule-soft);
  border-radius: 4px;
  background: transparent;
}

main details > summary {
  cursor: pointer;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.78rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
  font-weight: 500;
  list-style: none;
  padding: 0.25rem 0;
}

main details > summary::-webkit-details-marker { display: none; }

main details > summary::before {
  content: "▸";
  display: inline-block;
  margin-right: 0.5rem;
  transition: transform 200ms;
  color: var(--accent);
}

main details[open] > summary::before {
  transform: rotate(90deg);
}

main details > summary:hover { color: var(--ink); }

main details[open] { padding-bottom: 0.6rem; }

main details > *:not(summary) {
  margin-top: 0.6rem;
}

/* ---------- Live convergence widget ---------- */

.ml-widget {
  margin: 1.5rem 0 2rem;
  padding: 1.25rem;
  border: 1px solid var(--rule-soft);
  border-radius: 6px;
  background: var(--card);
  font-family: 'Libre Franklin', system-ui, sans-serif;
  color: var(--ink);
}

.ml-widget * { box-sizing: border-box; }

.ml-widget .conv-chart {
  position: relative;
  height: 320px;
  width: 100%;
  margin-bottom: 1rem;
}

.ml-widget .conv-chart canvas {
  width: 100% !important;
  height: 100% !important;
}

.ml-widget .conv-readout {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 0.5rem;
  margin-bottom: 1rem;
  padding: 0.6rem 0.4rem;
  border-top: 1px solid var(--rule-soft);
  border-bottom: 1px solid var(--rule-soft);
}

.ml-widget .rd {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.15rem;
}

.ml-widget .rd-l {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.65rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--muted);
}

.ml-widget .rd-v {
  font-family: 'JetBrains Mono', monospace;
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--ink);
  font-variant-numeric: tabular-nums;
}

.ml-widget .conv-controls {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.ml-widget .conv-btn {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  padding: 0.5rem 1rem;
  border: 1px solid var(--rule-soft);
  border-radius: 4px;
  background: transparent;
  color: var(--ink);
  cursor: pointer;
  transition: border-color 150ms, background-color 150ms;
}

.ml-widget .conv-btn:hover {
  border-color: var(--accent);
}

.ml-widget .conv-btn-primary {
  background: var(--accent);
  color: var(--bg);
  border-color: var(--accent);
}

.ml-widget .conv-btn-primary:hover {
  filter: brightness(1.08);
}

.ml-widget .conv-target {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.75rem;
  color: var(--muted);
  margin-left: auto;
}

.ml-widget .conv-target code {
  background: none;
  padding: 0;
  color: var(--ink);
}

@media (max-width: 540px) {
  .ml-widget .conv-readout {
    grid-template-columns: repeat(3, 1fr);
    row-gap: 0.6rem;
  }
  .ml-widget .conv-target {
    margin-left: 0;
    width: 100%;
  }
}

/* ---------- Convergence widget — chart + iteration table grid ----------
   Chart on the left (2fr), per-iteration table on the right (1fr),
   controls spanning both columns underneath. The table appends a row
   per gradient-descent step so the reader can watch the values feed
   the underlying function while the curve morphs. */

.conv-widget {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 2fr) minmax(0, 1fr);
  grid-template-rows: auto auto auto auto;
  grid-template-areas:
    "intro     intro"
    "stack     table"
    "controls  ."
    "explainer explainer";
  gap: 0.85rem;
}

.ml-widget > .ml-stack {
  grid-area: stack;
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
}

.conv-widget .conv-chart {
  height: 320px;
  margin-bottom: 0;
}

.conv-widget > .conv-controls {
  grid-area: controls;
}

.ml-widget > .iter-wrap {
  grid-area: table;
  position: absolute;
  inset: 0;
  overflow: auto;
  border: 1px solid var(--rule-soft);
  border-radius: 4px;
  background: var(--bg);
}

.conv-widget .conv-controls {
  margin-top: 0.15rem;
}

.ml-widget .iter-table {
  width: 100%;
  border-collapse: collapse;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.7rem;
  font-variant-numeric: tabular-nums;
  margin: 0;
}

.ml-widget .iter-table thead th {
  position: sticky;
  top: 1.7rem;
  z-index: 1;
  background: var(--card);
  color: var(--muted);
  padding: 0.4rem 0.45rem;
  text-align: right;
  font-weight: 500;
  font-size: 0.6rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  border-bottom: 1px solid var(--rule-soft);
}

.ml-widget .iter-table thead th:first-child { text-align: left; }

.ml-widget .iter-table tbody td {
  padding: 0.18rem 0.45rem;
  text-align: right;
  border-bottom: 1px solid rgba(94, 117, 101, 0.06);
  color: var(--ink);
}

.ml-widget .iter-table tbody td:first-child {
  text-align: left;
  color: var(--muted);
}

.ml-widget .iter-table tbody tr:last-child td {
  background: rgba(46, 110, 74, 0.12);
  color: var(--ink);
  font-weight: 700;
}

/* Polynomial widget uses the same chart+table grid, plus a third row
   for its parameter sliders (target, degree, noise). */

.poly-widget {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 2fr) minmax(0, 1fr);
  grid-template-rows: auto auto auto auto auto;
  grid-template-areas:
    "intro     intro"
    "stack     table"
    "controls  ."
    "params    ."
    "explainer explainer";
  gap: 0.85rem;
}

.poly-widget .conv-chart {
  height: 320px;
  margin-bottom: 0;
}

.poly-widget > .conv-controls {
  grid-area: controls;
}

.poly-widget > .ml-params {
  grid-area: params;
  margin-top: 0;
  padding-top: 0.85rem;
}

.ml-widget .tbl-title {
  position: sticky;
  top: 0;
  z-index: 3;
  background: var(--card);
  border-bottom: 1px solid var(--rule-soft);
  padding: 0.45rem 0.6rem;
  height: 1.7rem;
  box-sizing: border-box;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink);
  line-height: 1;
  display: flex;
  align-items: center;
}

/* Prominent loss readout floating in the chart's top-right corner —
   the thing the optimizer is trying to drive to zero. */
.ml-widget .chart-loss {
  position: absolute;
  top: 0.5rem;
  right: 0.65rem;
  z-index: 2;
  pointer-events: none;
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  padding: 0.35rem 0.65rem 0.4rem;
  background: rgba(25, 50, 42, 0.72);
  border: 1px solid var(--rule-soft);
  border-radius: 4px;
  backdrop-filter: blur(2px);
}

:root[data-theme="light"] .ml-widget .chart-loss {
  background: rgba(245, 243, 237, 0.82);
}

.ml-widget .chart-loss .cl-label {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.62rem;
  text-transform: uppercase;
  letter-spacing: 0.16em;
  color: var(--muted);
  line-height: 1;
  margin-bottom: 0.25rem;
}

.ml-widget .chart-loss .cl-val {
  font-family: 'JetBrains Mono', monospace;
  font-size: 2.2rem;
  font-weight: 700;
  color: var(--accent);
  font-variant-numeric: tabular-nums;
  line-height: 1;
}

.ml-widget > .widget-intro {
  grid-area: intro;
  padding: 1rem 1.1rem 0.85rem;
  border: 1px solid var(--rule-soft);
  border-radius: 4px;
  background: var(--card);
}

.ml-widget > .widget-intro h2 {
  font-family: 'Fraunces', Georgia, serif;
  font-weight: 400;
  font-size: clamp(1.4rem, 2.4vw, 1.7rem);
  line-height: 1.2;
  margin: 0 0 0.55rem;
  color: var(--ink);
}

.ml-widget > .widget-intro p {
  margin: 0 0 0.5rem;
  line-height: 1.55;
}

.ml-widget > .widget-intro p:last-child { margin-bottom: 0; }

.ml-widget > .widget-explainer {
  grid-area: explainer;
  padding: 0.95rem 1rem;
  border: 1px solid var(--rule-soft);
  border-radius: 4px;
  background: var(--card);
}

.ml-widget > .widget-explainer p {
  margin: 0 0 0.6rem;
  line-height: 1.55;
}

.ml-widget > .widget-explainer p:last-child {
  margin-bottom: 0;
}

.ml-widget .equation {
  display: flex;
  align-items: baseline;
  gap: 0.7rem;
  flex-wrap: wrap;
  padding: 0.5rem 0.7rem;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.78rem;
  font-variant-numeric: tabular-nums;
  background: var(--bg);
  border: 1px solid var(--rule-soft);
  border-radius: 4px;
  color: var(--ink);
  line-height: 1.4;
}

.ml-widget .equation .eq-label {
  color: var(--muted);
  font-size: 0.62rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.ml-widget .equation .eq-body {
  flex: 1;
  min-width: 0;
  overflow-x: auto;
  white-space: nowrap;
}

.ml-widget .equation .eq-loss {
  margin-left: auto;
  color: var(--muted);
  font-size: 0.72rem;
}

.ml-widget .equation .eq-loss strong {
  color: var(--accent);
  font-weight: 700;
}

.ml-widget .pred-wrap {
  height: 360px;
  overflow: auto;
  border: 1px solid var(--rule-soft);
  border-radius: 4px;
  background: var(--bg);
}

.ml-widget .pred-table {
  width: 100%;
  border-collapse: collapse;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.68rem;
  font-variant-numeric: tabular-nums;
  margin: 0;
}

.ml-widget .pred-table th,
.ml-widget .pred-table td {
  padding: 0.18rem 0.4rem;
  text-align: right;
  border-bottom: 1px solid rgba(94, 117, 101, 0.06);
}

.ml-widget .pred-table thead th {
  position: sticky;
  top: 1.7rem;
  z-index: 1;
  background: var(--card);
  color: var(--muted);
  font-size: 0.58rem;
  line-height: 1;
  height: 1.3rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  font-weight: 500;
  border-bottom: 1px solid var(--rule-soft);
}

.ml-widget .pred-table thead th:first-child { text-align: left; }

.ml-widget .pred-table tr.pred-true th,
.ml-widget .pred-table tr.pred-true td {
  position: sticky;
  top: 3rem;
  background-color: #ddd5c5;
  color: #5e5240;
  font-weight: 700;
  border-bottom: 1px solid var(--rule-soft);
}

:root[data-theme="dark"] .ml-widget .pred-table tr.pred-true th,
:root[data-theme="dark"] .ml-widget .pred-table tr.pred-true td {
  background-color: #2a2c22;
  color: var(--warm);
}

.ml-widget .pred-table tr.pred-true th { text-align: left; }

.ml-widget .pred-table tbody td:first-child {
  text-align: left;
  color: var(--muted);
}

.ml-widget .pred-table tbody tr:last-child td {
  background: rgba(46, 110, 74, 0.12);
  color: var(--ink);
  font-weight: 700;
}

@media (max-width: 640px) {
  .conv-widget,
  .poly-widget {
    position: static;
    display: flex;
    flex-direction: column;
    align-items: stretch;
  }
  .ml-widget > .iter-wrap {
    position: static;
    height: 220px;
    inset: auto;
  }
  .ml-widget .equation .eq-loss { margin-left: 0; width: 100%; }
}

/* ---------- Shared parameter rows (used by polynomial, donut, tree, kernel) ---------- */

.ml-widget .ml-params {
  display: flex;
  flex-direction: column;
  gap: 0.7rem;
  margin-top: 1rem;
  padding-top: 1rem;
  border-top: 1px solid var(--rule-soft);
}

.ml-widget .ml-row {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.ml-widget .ml-label {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--muted);
  min-width: 70px;
}

.ml-widget .ml-pill {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.72rem;
  padding: 0.3rem 0.7rem;
  border: 1px solid var(--rule-soft);
  border-radius: 999px;
  background: transparent;
  color: var(--ink);
  cursor: pointer;
  transition: border-color 150ms, background-color 150ms, color 150ms;
}

.ml-widget .ml-pill:hover { border-color: var(--accent); }

.ml-widget .ml-pill.active {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--bg);
}

.ml-widget input[type="range"] {
  flex: 1;
  min-width: 100px;
  accent-color: var(--accent);
}

.ml-widget .ml-val {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--ink);
  min-width: 40px;
  text-align: right;
  font-variant-numeric: tabular-nums;
}