/* css/style.css */
/* StatChooser. Type: STIX Two Text (scientific publishing) + IBM Plex Mono. */

:root {
  /* Neutral black-and-white palette, shadcn-style. The teal/madder names are
     kept so existing rules need no change; only the values are neutral now. */
  --paper: #fafafa;        /* neutral-50 page background */
  --card: #ffffff;
  --ink: #09090b;          /* neutral-950 foreground */
  --ink-soft: #52525b;     /* neutral-600 muted text */
  --teal: #18181b;         /* neutral-900 primary */
  --teal-dark: #000000;    /* hover / strongest */
  --teal-wash: #f4f4f5;    /* neutral-100 subtle fill */
  --madder: #18181b;       /* accent collapses to near-black */
  --mist: #e4e4e7;         /* neutral-200 border */
  --mono-ink: #3f3f46;     /* neutral-700 */
  --radius: 10px;
  --shadow: 0 1px 2px rgba(9, 9, 11, 0.05), 0 1px 3px rgba(9, 9, 11, 0.06);
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: "STIX Two Text", "Times New Roman", Georgia, serif;
  font-size: 17px;
  line-height: 1.55;
}

.mono {
  font-family: "IBM Plex Mono", ui-monospace, "SF Mono", Consolas, monospace;
}

.wrap {
  max-width: 720px;
  margin: 0 auto;
  padding: 0 20px 72px;
}

/* ---------- masthead ---------- */

.masthead {
  padding: 34px 0 18px;
  border-bottom: 2px solid var(--ink);
}

.masthead h1 {
  margin: 0;
  font-size: 30px;
  font-weight: 600;
  letter-spacing: 0.01em;
}

.masthead h1 .sigma {
  color: var(--teal);
  font-weight: 700;
}

.masthead .tagline {
  margin: 8px 0 0;
  font-size: 16px;
  font-weight: 600;
  color: var(--ink);
  letter-spacing: -0.01em;
}

.masthead .strap {
  margin: 6px 0 0;
  font-size: 14.5px;
  color: var(--ink-soft);
}

.masthead .strap a {
  color: var(--teal);
  text-decoration: none;
  border-bottom: 1px solid var(--mist);
}

.masthead .strap a:hover { border-bottom-color: var(--teal); }

/* ---------- progress ---------- */

.stages {
  display: flex;
  gap: 8px;
  margin: 22px 0 16px;
  counter-reset: stage;
  font-family: "IBM Plex Mono", monospace;
  font-size: 11.5px;
  letter-spacing: 0.07em;
  text-transform: uppercase;
}

.stages span {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 7px;
  counter-increment: stage;
  padding: 10px 6px;
  border: 1.5px solid var(--mist);
  border-radius: 9px;
  background: var(--card);
  color: #a1a1aa;
  font-weight: 500;
  transition: background 0.2s, color 0.2s, border-color 0.2s, box-shadow 0.2s;
}

.stages span::before {
  content: counter(stage);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 19px;
  height: 19px;
  border-radius: 50%;
  background: #d4d4d8;
  color: #fff;
  font-size: 11px;
  font-weight: 700;
  flex: none;
}

.stages span.done {
  background: var(--teal-wash);
  border-color: var(--mist);
  color: var(--ink);
}

.stages span.done::before {
  content: "\2713";
  background: var(--teal);
}

.stages span.now {
  background: var(--card);
  border-color: var(--ink);
  border-width: 2px;
  color: var(--ink);
  font-weight: 700;
  box-shadow: 0 2px 9px rgba(9, 9, 11, 0.14);
}

.stages span.now::before { background: var(--madder); }

/* ---------- decision record (signature) ---------- */

.record {
  min-height: 30px;
  margin: 4px 0 20px;
  font-family: "IBM Plex Mono", monospace;
  font-size: 13px;
  color: var(--mono-ink);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px 2px;
}

.record .seg {
  background: none;
  border: none;
  padding: 3px 6px;
  font: inherit;
  color: inherit;
  cursor: pointer;
  border-radius: 5px;
  white-space: nowrap;
}

.record .seg:hover { background: var(--teal-wash); color: var(--teal-dark); }

.record .sep { color: #a1a1aa; user-select: none; }

.record .hint { color: #a1a1aa; padding: 3px 6px; }

/* ---------- question card ---------- */

.card {
  background: var(--card);
  border: 1px solid var(--mist);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 28px 28px 24px;
  animation: rise 0.28s ease both;
}

@keyframes rise {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: none; }
}

@media (prefers-reduced-motion: reduce) {
  .card { animation: none; }
}

.card h2 {
  margin: 0 0 6px;
  font-size: 23px;
  font-weight: 600;
  line-height: 1.3;
}

.card .help {
  margin: 0 0 18px;
  font-size: 15px;
  color: var(--ink-soft);
}

.opts { display: grid; gap: 10px; }

.opt {
  display: block;
  width: 100%;
  text-align: left;
  background: var(--card);
  border: 1.5px solid var(--mist);
  border-radius: 8px;
  padding: 14px 16px;
  font-family: inherit;
  font-size: 17px;
  color: var(--ink);
  cursor: pointer;
  transition: border-color 0.15s, background 0.15s;
}

.opt:hover { border-color: var(--teal); background: var(--teal-wash); }

.opt:focus-visible,
.seg:focus-visible,
.tab:focus-visible,
.btn:focus-visible {
  outline: 2.5px solid var(--madder);
  outline-offset: 2px;
}

.opt .sub {
  display: block;
  font-size: 14px;
  color: var(--ink-soft);
  margin-top: 2px;
}

.backrow { margin-top: 18px; font-size: 14.5px; }

.linklike {
  background: none;
  border: none;
  padding: 0;
  font: inherit;
  color: var(--teal);
  cursor: pointer;
  border-bottom: 1px solid var(--mist);
}

.linklike:hover { border-bottom-color: var(--teal); }

/* ---------- result ---------- */

.verdict { border-left: 4px solid var(--madder); padding-left: 18px; margin-bottom: 6px; }

.verdict .eyebrow {
  font-family: "IBM Plex Mono", monospace;
  font-size: 11.5px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--madder);
}

.verdict h2 { margin: 4px 0 8px; font-size: 27px; }

.token {
  display: inline-block;
  font-family: "IBM Plex Mono", monospace;
  font-size: 13px;
  background: var(--teal-wash);
  color: var(--teal-dark);
  border: 1px solid var(--mist);
  border-radius: 6px;
  padding: 2px 9px;
  margin-bottom: 10px;
}

.verdict p { margin: 6px 0 0; }

/* beginner example callout */
.example {
  margin: 16px 0 0;
  background: var(--teal-wash);
  border: 1px solid var(--mist);
  border-left: 3px solid var(--ink);
  border-radius: 8px;
  padding: 13px 16px;
}

.example-label {
  display: block;
  font-family: "IBM Plex Mono", monospace;
  font-size: 11px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink-soft);
  margin-bottom: 4px;
}

.example-text {
  display: block;
  font-size: 16px;
  color: var(--ink);
}

.tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 2px;
  margin: 22px 0 0;
  border-bottom: 1.5px solid var(--mist);
}

.tab {
  background: none;
  border: none;
  font-family: inherit;
  font-size: 15px;
  padding: 8px 12px 9px;
  color: var(--ink-soft);
  cursor: pointer;
  border-bottom: 2.5px solid transparent;
  margin-bottom: -1.5px;
}

.tab:hover { color: var(--ink); }
.tab.on { color: var(--ink); font-weight: 600; border-bottom-color: var(--madder); }

.pane { padding: 18px 2px 4px; }

.pane ul { margin: 4px 0; padding-left: 22px; }
.pane li { margin: 7px 0; }
.pane ol { margin: 4px 0; padding-left: 22px; }

.pane .note { font-size: 14.5px; color: var(--ink-soft); margin-top: 14px; }

pre.code {
  font-family: "IBM Plex Mono", monospace;
  font-size: 13px;
  line-height: 1.55;
  background: #18181b;
  color: #e4e4e7;
  border-radius: 8px;
  padding: 16px 18px;
  overflow-x: auto;
  white-space: pre;
  margin: 6px 0 10px;
}

.reportbox {
  font-size: 16.5px;
  background: var(--teal-wash);
  border-radius: 8px;
  padding: 16px 18px;
  margin: 6px 0 10px;
}

/* ---------- survey preview ---------- */

.survey {
  border: 1px solid var(--mist);
  border-radius: 10px;
  background: #fcfdfc;
  padding: 18px 20px 20px;
  margin: 8px 0 4px;
}

.survey-title {
  font-size: 19px;
  font-weight: 600;
  color: #a1a1aa;
  font-style: italic;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--mist);
  margin-bottom: 14px;
}

.survey-section { margin-bottom: 18px; }

.survey-sec-head {
  font-family: "IBM Plex Mono", monospace;
  font-size: 12px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--ink);
  background: var(--teal-wash);
  border: 1px solid var(--mist);
  border-radius: 6px;
  padding: 7px 11px;
  margin-bottom: 10px;
}

.survey-sec-intro {
  font-size: 14px;
  color: var(--ink-soft);
  margin: -4px 2px 12px;
}

.survey-q { margin: 0 0 15px; padding-left: 2px; }

.survey-label { font-size: 15.5px; margin-bottom: 7px; }

.survey-tag {
  display: inline-block;
  font-family: "IBM Plex Mono", monospace;
  font-size: 9.5px;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--ink-soft);
  border: 1px solid var(--mist);
  background: var(--teal-wash);
  border-radius: 4px;
  padding: 1px 5px;
  margin-left: 8px;
  vertical-align: middle;
}

.survey-likert { display: flex; flex-wrap: wrap; gap: 6px 14px; }
.survey-opts { display: grid; gap: 7px; }

.survey-opt {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  font-size: 14px;
  color: var(--ink-soft);
}

.survey-radio {
  width: 14px;
  height: 14px;
  border: 1.5px solid #d4d4d8;
  border-radius: 50%;
  flex: none;
}

.survey-num-box {
  display: inline-block;
  min-width: 90px;
  border: 1.5px solid var(--mist);
  border-radius: 6px;
  padding: 6px 10px;
  font-family: "IBM Plex Mono", monospace;
  font-size: 13px;
  color: #a1a1aa;
  background: #fff;
}

.cta {
  margin-top: 16px;
  padding: 16px 18px;
  border: 1px solid var(--mist);
  background: var(--teal-wash);
  border-radius: 9px;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
}

.cta-text {
  margin: 0;
  font-size: 15px;
  font-weight: 600;
  color: var(--ink);
}

/* ---------- export row ---------- */

.exports {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 20px;
  padding-top: 18px;
  border-top: 1px solid var(--mist);
}

.btn {
  font-family: "IBM Plex Mono", monospace;
  font-size: 12.5px;
  background: var(--card);
  color: var(--teal-dark);
  border: 1.5px solid var(--teal);
  border-radius: 7px;
  padding: 8px 13px;
  cursor: pointer;
  transition: background 0.15s;
}

.btn:hover { background: var(--teal-wash); }

.btn.primary { background: var(--teal); color: #fff; }
.btn.primary:hover { background: var(--teal-dark); }

/* ---------- next steps and citation ---------- */

.nextsteps {
  margin-top: 26px;
  background: var(--card);
  border: 1px solid var(--mist);
  border-radius: var(--radius);
  padding: 20px 24px;
}

.nextsteps h3 {
  margin: 0 0 8px;
  font-size: 16px;
  font-weight: 600;
}

.nextsteps p { margin: 8px 0; font-size: 15.5px; }
.nextsteps a { color: var(--teal); }

/* ---------- cross-reference block ---------- */

.related {
  margin-top: 18px;
  background: var(--card);
  border: 1px solid var(--mist);
  border-radius: var(--radius);
  padding: 22px 24px 20px;
}

.related-head h3 {
  margin: 0 0 4px;
  font-size: 18px;
  font-weight: 600;
}

.related-sub {
  margin: 0 0 16px;
  font-size: 14.5px;
  color: var(--ink-soft);
}

.related-grid {
  display: grid;
  gap: 12px;
  grid-template-columns: repeat(auto-fit, minmax(190px, 1fr));
}

.related-card {
  border: 1px solid var(--mist);
  border-radius: 8px;
  padding: 15px 16px 16px;
  display: flex;
  flex-direction: column;
  background: #fcfdfc;
}

/* accent the textbook, the small-sample anchor of the trio */
.related-card:nth-child(2) {
  background: var(--teal-wash);
  border-color: var(--ink);
}

.related-tag {
  font-size: 10.5px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--ink-soft);
  margin-bottom: 5px;
}

.related-name {
  font-size: 16.5px;
  font-weight: 600;
  line-height: 1.3;
}

.related-blurb {
  margin: 7px 0 14px;
  font-size: 14px;
  color: var(--ink-soft);
  flex: 1;
}

.related-cta {
  align-self: flex-start;
  font-size: 12.5px;
}

.related-card:nth-child(2) .related-cta {
  background: var(--teal);
  color: #fff;
  border-color: var(--teal);
}

.related-card:nth-child(2) .related-cta:hover { background: var(--teal-dark); }

.related-note {
  margin: 14px 0 0;
  font-size: 12.5px;
  color: #a1a1aa;
}

.citefoot {
  margin-top: 26px;
  font-size: 13.5px;
  color: var(--ink-soft);
  border-top: 1px solid var(--mist);
  padding-top: 14px;
}

.citefoot .mono { font-size: 12px; }

/* ---------- FAQ ---------- */

.faq {
  margin-top: 30px;
  padding-top: 22px;
  border-top: 1px solid var(--mist);
}

.faq h2 {
  margin: 0 0 12px;
  font-size: 18px;
  font-weight: 600;
}

.faq details {
  border: 1px solid var(--mist);
  border-radius: 9px;
  background: var(--card);
  padding: 0 16px;
  margin-bottom: 8px;
  box-shadow: var(--shadow);
}

.faq summary {
  cursor: pointer;
  list-style: none;
  padding: 13px 0;
  font-size: 15.5px;
  font-weight: 600;
  color: var(--ink);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
}

.faq summary::-webkit-details-marker { display: none; }

.faq summary::after {
  content: "+";
  font-family: "IBM Plex Mono", monospace;
  font-size: 18px;
  color: var(--ink-soft);
  flex: none;
}

.faq details[open] summary::after { content: "\2212"; }

.faq details[open] summary { border-bottom: 1px solid var(--mist); }

.faq details p {
  margin: 12px 0 16px;
  font-size: 15px;
  color: var(--ink-soft);
}

.faq details a { color: var(--teal); }

footer.site {
  margin-top: 40px;
  font-size: 13.5px;
  color: var(--ink-soft);
}

footer.site a { color: var(--teal); }

.toast {
  position: fixed;
  left: 50%;
  bottom: 28px;
  transform: translateX(-50%);
  background: var(--ink);
  color: #fff;
  font-family: "IBM Plex Mono", monospace;
  font-size: 13px;
  padding: 9px 16px;
  border-radius: 7px;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.2s;
}

.toast.show { opacity: 1; }

@media (max-width: 480px) {
  body { font-size: 16px; }
  .card { padding: 20px 18px 18px; }
  .masthead h1 { font-size: 25px; }
  .verdict h2 { font-size: 23px; }
  .stages { font-size: 9.5px; gap: 5px; letter-spacing: 0.03em; }
  .stages span { padding: 8px 3px; gap: 5px; border-radius: 8px; }
  .stages span::before { width: 16px; height: 16px; font-size: 10px; }
}