/* ============================================================
   Rizkin Labs, Writing
   Shared stylesheet for the thought-leadership section.
   Every article and the hub link this one file. New pieces
   inherit the design automatically; see _template.html.
   ============================================================ */

:root {
  --ink: #0B0E14;
  --ink-2: #10141D;
  --ink-3: #161B27;
  --indigo: #232B3E;
  --amber: #D08A3C;
  --amber-hi: #F5E3C0;
  --paper: #EDE8DC;
  --slate: #8A93A6;
  --slate-hi: #AEB6C6;
  --hairline: rgba(208, 138, 60, 0.22);
  --rule: rgba(138, 147, 166, 0.18);
  --measure: 42rem;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  background: var(--ink);
  color: var(--paper);
  font-family: "Instrument Sans", system-ui, sans-serif;
  font-size: 18px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
::selection { background: var(--amber); color: var(--ink); }
a { color: inherit; }
a:focus-visible, button:focus-visible, input:focus-visible, select:focus-visible {
  outline: 2px solid var(--amber);
  outline-offset: 3px;
}
img { max-width: 100%; }

.mono {
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--slate);
}

/* ---------- top bar ---------- */
.site-nav {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 1rem;
  padding: 1.1rem clamp(1.4rem, 5vw, 4.5rem);
  background: rgba(11, 14, 20, 0.85);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--rule);
}
.site-nav a { text-decoration: none; transition: color 160ms ease; }
.site-nav a:hover { color: var(--amber-hi); }
.site-nav .brand { color: var(--paper); }
.site-nav .brand b { font-weight: 500; }

/* reading progress */
#progress {
  position: fixed;
  top: 0; left: 0;
  height: 2px;
  width: 0%;
  background: var(--amber);
  z-index: 30;
  transition: width 90ms linear;
}

/* ---------- shared layout ---------- */
.wrap {
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 clamp(1.4rem, 5vw, 4.5rem);
}

/* ============================================================
   HUB (index.html)
   ============================================================ */
.hub-hero {
  padding: clamp(3rem, 9vh, 6rem) 0 clamp(2rem, 5vh, 3.5rem);
  border-bottom: 1px solid var(--rule);
}
.hub-hero h1 {
  font-family: "Instrument Serif", serif;
  font-weight: 400;
  font-size: clamp(2.8rem, 8vw, 5.2rem);
  line-height: 1;
  letter-spacing: -0.01em;
}
.hub-hero h1 em { font-style: italic; color: var(--amber); }
.hub-hero .dek {
  margin-top: 1.2rem;
  max-width: 46ch;
  font-size: clamp(1.05rem, 2vw, 1.28rem);
  color: var(--slate-hi);
}

.section-label {
  margin: clamp(2.4rem, 6vh, 4rem) 0 1.4rem;
  display: flex;
  align-items: baseline;
  gap: 0.8rem;
}
.section-label::after {
  content: "";
  flex: 1;
  height: 1px;
  background: var(--rule);
}

.pieces { display: grid; gap: 1px; background: var(--rule); border: 1px solid var(--rule); }
.piece {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 0.4rem 2rem;
  align-items: start;
  padding: clamp(1.4rem, 3vw, 2.1rem);
  background: var(--ink);
  text-decoration: none;
  transition: background 200ms ease;
}
.piece:hover { background: var(--ink-2); }
.piece .p-kicker { color: var(--amber); margin-bottom: 0.7rem; }
.piece h2 {
  font-family: "Instrument Serif", serif;
  font-weight: 400;
  font-size: clamp(1.5rem, 3vw, 2rem);
  line-height: 1.08;
  color: var(--paper);
}
.piece:hover h2 { color: var(--amber-hi); }
.piece .p-dek { margin-top: 0.6rem; color: var(--slate-hi); font-size: 0.98rem; max-width: 60ch; }
.piece .p-meta { grid-column: 1; margin-top: 0.9rem; display: flex; gap: 1.2rem; flex-wrap: wrap; }
.piece .p-read { grid-column: 2; grid-row: 1 / span 4; align-self: center; color: var(--slate); transition: transform 200ms ease, color 200ms ease; }
.piece:hover .p-read { color: var(--amber-hi); transform: translateX(4px); }

/* reference tools on hub */
.tools { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 1.2rem; }
.tool-card {
  background: var(--ink-2);
  border: 1px solid var(--rule);
  padding: 1.4rem 1.5rem 1.6rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
  transition: border-color 200ms ease;
}
.tool-card:hover { border-color: var(--hairline); }
.tool-card h3 {
  font-family: "Instrument Serif", serif;
  font-weight: 400;
  font-style: italic;
  font-size: 1.35rem;
  color: var(--paper);
}
.tool-card .tc-head { display: flex; justify-content: space-between; align-items: baseline; gap: 0.8rem; }
.tool-card .tc-head .mono { color: var(--amber); flex: none; }
.tool-card .tc-blurb { font-size: 0.86rem; color: var(--slate); margin-top: -0.5rem; }

.field {
  width: 100%;
  background: var(--ink);
  border: 1px solid rgba(138,147,166,0.3);
  color: var(--paper);
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.82rem;
  padding: 0.5rem 0.6rem;
  border-radius: 0;
  -webkit-appearance: none;
  appearance: none;
}
.field:focus { border-color: var(--amber); outline: none; }

.chips { display: flex; flex-wrap: wrap; gap: 0.4rem; }
.chip {
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.68rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 0.3rem 0.55rem;
  background: var(--ink);
  border: 1px solid rgba(138,147,166,0.3);
  color: var(--paper);
  cursor: pointer;
  transition: border-color 160ms ease, color 160ms ease, background 160ms ease;
}
.chip:hover { border-color: var(--amber); color: var(--amber-hi); }
.chip.on { border-color: var(--amber); color: var(--ink); background: var(--amber); }

.result-list { display: flex; flex-direction: column; max-height: 320px; overflow-y: auto; }
.result-list .row {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 0.2rem 1rem;
  padding: 0.65rem 0;
  border-top: 1px solid var(--rule);
  font-size: 0.9rem;
}
.result-list .row .code { font-family: "IBM Plex Mono", monospace; color: var(--amber-hi); font-size: 0.82rem; white-space: nowrap; }
.result-list .row .name { color: var(--paper); }
.result-list .row .sub { grid-column: 2; color: var(--slate); font-size: 0.8rem; }
.result-list .empty { padding: 1rem 0; color: var(--slate); font-size: 0.85rem; }

/* phase navigator */
.phase-tabs { display: flex; flex-wrap: wrap; gap: 0.35rem; }
.phase-tabs button {
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.68rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  padding: 0.4rem 0.6rem;
  background: var(--ink);
  border: 1px solid rgba(138,147,166,0.3);
  color: var(--paper);
  cursor: pointer;
}
.phase-tabs button.on { border-color: var(--amber); color: var(--ink); background: var(--amber); }
.phase-body { font-size: 0.9rem; display: flex; flex-direction: column; gap: 0.8rem; }
.phase-body .pb-block .mono { color: var(--amber); display: block; margin-bottom: 0.35rem; }
.phase-body ul { list-style: none; display: flex; flex-direction: column; gap: 0.25rem; }
.phase-body li { padding-left: 1rem; position: relative; color: var(--paper); }
.phase-body li::before { content: "→"; position: absolute; left: 0; color: var(--slate); }
.phase-body .gate { border-top: 1px solid var(--rule); padding-top: 0.7rem; }
.phase-body .gate .v { color: var(--amber-hi); }

/* ============================================================
   ARTICLE (doc pages)
   ============================================================ */
.doc-head {
  max-width: var(--measure);
  margin: 0 auto;
  padding: clamp(2.4rem, 7vh, 5rem) 0 clamp(1.6rem, 4vh, 2.6rem);
}
.doc-kicker { color: var(--amber); margin-bottom: 1.1rem; }
.doc-title {
  font-family: "Instrument Serif", serif;
  font-weight: 400;
  font-size: clamp(2.3rem, 5.5vw, 3.7rem);
  line-height: 1.03;
  letter-spacing: -0.01em;
  color: var(--paper);
}
.doc-dek {
  margin-top: 1.1rem;
  font-size: clamp(1.1rem, 2.2vw, 1.35rem);
  color: var(--slate-hi);
  line-height: 1.5;
}
.doc-meta {
  margin-top: 1.6rem;
  padding-top: 1.1rem;
  border-top: 1px solid var(--rule);
  display: flex;
  flex-wrap: wrap;
  gap: 1.4rem;
}
.doc-meta .byline { color: var(--paper); }

.doc-body { max-width: var(--measure); margin: 0 auto; padding-bottom: 4rem; }
.doc-body > * + * { margin-top: 1.3rem; }
.doc-body .lede { font-size: 1.2rem; color: var(--paper); }
.doc-body .lede::first-letter {
  font-family: "Instrument Serif", serif;
  font-size: 3.4rem;
  line-height: 0.8;
  float: left;
  padding: 0.2rem 0.6rem 0 0;
  color: var(--amber);
}
.doc-body h2 {
  font-family: "Instrument Serif", serif;
  font-weight: 400;
  font-size: clamp(1.7rem, 3.4vw, 2.3rem);
  line-height: 1.12;
  color: var(--paper);
  margin-top: 2.8rem;
  padding-top: 0.4rem;
  scroll-margin-top: 5rem;
}
.doc-body h3 {
  font-family: "Instrument Sans", sans-serif;
  font-weight: 500;
  font-size: 1.16rem;
  color: var(--amber-hi);
  margin-top: 2rem;
  scroll-margin-top: 5rem;
}
.doc-body p { color: var(--paper); }
.doc-body a[href] { color: var(--amber-hi); text-underline-offset: 3px; }
.doc-body strong { color: var(--paper); font-weight: 600; }
.doc-body em { font-style: italic; }
.doc-body ul, .doc-body ol { padding-left: 1.4rem; display: flex; flex-direction: column; gap: 0.5rem; }
.doc-body li { color: var(--paper); }
.doc-body li::marker { color: var(--amber); }

.doc-body .pull {
  border-left: 2px solid var(--amber);
  padding: 0.3rem 0 0.3rem 1.4rem;
  margin: 2rem 0;
  font-family: "Instrument Serif", serif;
  font-size: 1.5rem;
  line-height: 1.35;
  color: var(--amber-hi);
  font-style: italic;
}
.doc-body .pull cite { display: block; margin-top: 0.7rem; font-family: "IBM Plex Mono", monospace; font-style: normal; font-size: 0.72rem; letter-spacing: 0.1em; text-transform: uppercase; color: var(--slate); }

.doc-body .callout {
  background: var(--ink-2);
  border: 1px solid var(--rule);
  border-left: 2px solid var(--slate);
  padding: 1.1rem 1.3rem;
  margin: 1.8rem 0;
}
.doc-body .callout .c-label {
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.68rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--slate);
  margin-bottom: 0.5rem;
}
.doc-body .callout p { font-size: 0.98rem; }
.doc-body .callout.reg { border-left-color: var(--amber); }
.doc-body .callout.reg .c-label { color: var(--amber); }
.doc-body .callout.insight { border-left-color: var(--amber-hi); }
.doc-body .callout.insight .c-label { color: var(--amber-hi); }

/* tables, the technical spine of this content */
.table-wrap { margin: 1.8rem 0; overflow-x: auto; border: 1px solid var(--rule); }
.doc-body table.data, table.data {
  border-collapse: collapse;
  width: 100%;
  min-width: 32rem;
  font-size: 0.9rem;
}
table.data caption {
  text-align: left;
  padding: 0.7rem 0.9rem;
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.68rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--slate);
  border-bottom: 1px solid var(--rule);
}
table.data th, table.data td {
  text-align: left;
  vertical-align: top;
  padding: 0.6rem 0.9rem;
  border-bottom: 1px solid var(--rule);
}
table.data thead th {
  background: var(--ink-3);
  color: var(--amber);
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.68rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  font-weight: 500;
  position: sticky;
  top: 0;
}
table.data tbody tr:nth-child(even) { background: rgba(16, 20, 29, 0.6); }
table.data tbody td:first-child { color: var(--amber-hi); }
table.data code { font-family: "IBM Plex Mono", monospace; font-size: 0.82em; color: var(--amber-hi); }

/* metric / stat row */
.stat-row { display: grid; grid-template-columns: repeat(auto-fit, minmax(140px, 1fr)); gap: 1px; background: var(--rule); border: 1px solid var(--rule); margin: 1.8rem 0; }
.stat-row .stat { background: var(--ink); padding: 1.1rem 1.2rem; }
.stat-row .stat .n { font-family: "Instrument Serif", serif; font-size: 2.2rem; line-height: 1; color: var(--amber); }
.stat-row .stat .l { margin-top: 0.4rem; font-size: 0.82rem; color: var(--slate); }

/* footnote-style references / TOC */
.doc-refs { max-width: var(--measure); margin: 2rem auto 0; padding: 1.6rem 0 0; border-top: 1px solid var(--rule); }
.doc-refs h2 { font-family: "Instrument Serif", serif; font-weight: 400; font-size: 1.5rem; margin-bottom: 0.9rem; }
.doc-refs ol { padding-left: 1.3rem; font-size: 0.86rem; color: var(--slate-hi); display: flex; flex-direction: column; gap: 0.4rem; }

.doc-toc {
  max-width: var(--measure);
  margin: 0 auto 2rem;
  padding: 1.1rem 1.3rem;
  background: var(--ink-2);
  border: 1px solid var(--rule);
}
.doc-toc .mono { color: var(--amber); }
.doc-toc ol { list-style: none; margin-top: 0.7rem; display: flex; flex-direction: column; gap: 0.35rem; counter-reset: toc; }
.doc-toc li { counter-increment: toc; }
.doc-toc a { text-decoration: none; color: var(--slate-hi); font-size: 0.92rem; transition: color 160ms ease; }
.doc-toc a::before { content: counter(toc, decimal-leading-zero) "  "; font-family: "IBM Plex Mono", monospace; font-size: 0.72rem; color: var(--slate); }
.doc-toc a:hover { color: var(--amber-hi); }

.doc-foot {
  border-top: 1px solid var(--rule);
  margin-top: 3rem;
  padding: 2.4rem 0 3rem;
}
.doc-foot .wrap { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 1.2rem; align-items: baseline; }
.doc-foot a { text-decoration: none; }
.doc-foot a:hover { color: var(--amber-hi); }

/* generic disclaimer + footer */
.fine { color: var(--slate); font-size: 0.82rem; }
footer.site {
  border-top: 1px solid var(--rule);
  padding: 1.6rem 0;
  margin-top: 2rem;
}
footer.site .wrap { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 0.8rem; }

@media (max-width: 640px) {
  body { font-size: 17px; }
  .piece { grid-template-columns: 1fr; }
  .piece .p-read { grid-column: 1; grid-row: auto; margin-top: 0.6rem; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  #progress { transition: none; }
  .piece .p-read, .piece:hover .p-read { transition: none; transform: none; }
}