/* Numerical Reasoning article. High-fidelity editorial layout. */

body.blog-article-page {
  background: var(--clr-surface);
  color: var(--clr-text);
  overflow-x: clip;
}

.nr-article-progress {
  position: fixed;
  inset: 0 0 auto;
  z-index: var(--z-toast);
  height: 3px;
  background: color-mix(in srgb, var(--clr-primary) 8%, transparent);
  pointer-events: none;
}

.nr-article-progress span {
  display: block;
  width: 0;
  height: 100%;
  background: var(--gradient-gold);
  transition: width var(--motion-fast);
}

.nr-article {
  padding: var(--space-3) 0 var(--space-24);
}

.nr-article-shell {
  width: min(calc(100% - var(--space-8)), 1240px);
  margin-inline: auto;
}

.nr-article-layout {
  display: grid;
  grid-template-columns: 210px minmax(0, 1fr);
  gap: var(--space-10);
  align-items: start;
}

.nr-article-main {
  min-width: 0;
}

.nr-article-mobile-guide {
  display: none;
}

.nr-article-rail {
  position: sticky;
  top: calc(var(--header-height) + var(--space-5));
  min-width: 0;
  padding: var(--space-2) var(--space-5) 0 0;
  border-right: 1px solid var(--clr-border-light);
}

.nr-article-back {
  display: inline-flex;
  min-height: 44px;
  align-items: center;
  gap: var(--space-2);
  margin-bottom: var(--space-7);
  color: var(--clr-text-muted);
  font-size: var(--text-sm);
  font-weight: var(--weight-bold);
  text-decoration: none;
  transition:
    color var(--motion-fast),
    transform var(--motion-fast);
}

.nr-article-back:hover,
.nr-article-back:focus-visible {
  color: var(--clr-text);
  transform: translateX(-2px);
}

.nr-article-rail-title {
  margin: 0 0 var(--space-4);
  color: var(--clr-text);
  font-family: var(--font-display);
  font-size: var(--text-sm);
  font-weight: var(--weight-extrabold);
  letter-spacing: 0;
  text-transform: uppercase;
}

.nr-article-toc {
  display: grid;
  gap: var(--space-4);
}

.nr-article-toc a {
  display: grid;
  grid-template-columns: 18px minmax(0, 1fr);
  gap: var(--space-3);
  min-height: 44px;
  align-items: start;
  padding-left: var(--space-3);
  border-left: 2px solid transparent;
  color: var(--clr-text-muted);
  font-size: var(--text-sm);
  font-weight: var(--weight-medium);
  line-height: var(--leading-snug);
  text-decoration: none;
  transition:
    border-color var(--motion-fast),
    color var(--motion-fast),
    transform var(--motion-fast);
}

.nr-article-toc a span:first-child {
  color: var(--clr-text-subtle);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
}

.nr-article-toc a:hover,
.nr-article-toc a:focus-visible,
.nr-article-toc a.is-active {
  border-color: var(--clr-gold);
  color: var(--clr-text);
  transform: translateX(2px);
}

.nr-article-toc a.is-active span:first-child {
  color: var(--clr-gold-dark);
}

.nr-article-rail-cta {
  display: grid;
  gap: var(--space-3);
  margin-top: var(--space-10);
  padding: var(--space-5);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius-sm);
  background: var(--clr-surface);
  box-shadow: var(--shadow-xs);
}

.nr-article-rail-cta-icon {
  color: var(--clr-gold-dark);
}

.nr-article-rail-cta p {
  margin: 0;
  color: var(--clr-text);
  font-size: var(--text-sm);
  font-weight: var(--weight-semibold);
  line-height: var(--leading-normal);
}

.nr-article-rail-cta a {
  color: var(--clr-gold-dark);
  font-size: var(--text-sm);
  font-weight: var(--weight-extrabold);
  text-decoration: none;
}

.nr-article-hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 430px;
  gap: var(--space-4);
  align-items: center;
  padding-top: var(--space-3);
}

.nr-article-meta {
  margin-bottom: var(--space-4);
}

.nr-article-tag {
  color: var(--clr-gold-dark);
  font-size: var(--text-xs);
  font-weight: var(--weight-extrabold);
  letter-spacing: 0;
  text-transform: uppercase;
}

.nr-article-title {
  max-width: 21ch;
  margin: 0;
  color: var(--clr-text);
  font-family: Georgia, "Times New Roman", serif;
  font-size: var(--text-5xl);
  font-weight: var(--weight-bold);
  letter-spacing: 0;
  line-height: 1.04;
  text-wrap: balance;
}

.nr-article-lead {
  max-width: 66ch;
  margin: var(--space-4) 0 0;
  color: var(--clr-text-muted);
  font-size: var(--text-base);
  line-height: var(--leading-relaxed);
}

.nr-article-hero-tools {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-5);
  margin-top: var(--space-6);
}

.nr-article-meta-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-3);
  color: var(--clr-text-muted);
  font-size: var(--text-sm);
  font-weight: var(--weight-medium);
}

.nr-article-meta-item {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
}

.nr-article-hero-actions {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.nr-article-share,
.nr-article-copy,
.nr-article-action {
  display: inline-grid;
  width: 44px;
  height: 44px;
  place-items: center;
  border: 1px solid var(--clr-border);
  border-radius: var(--radius-full);
  background: var(--clr-surface);
  color: var(--clr-primary);
  box-shadow: var(--shadow-xs);
  cursor: pointer;
  font-family: var(--font-body);
  font-size: var(--text-sm);
  font-weight: var(--weight-extrabold);
  line-height: 1;
  text-decoration: none;
  transition:
    border-color var(--motion-fast),
    box-shadow var(--motion-fast),
    color var(--motion-fast),
    transform var(--motion-fast);
}

.nr-article-share:hover,
.nr-article-copy:hover,
.nr-article-action:hover,
.nr-article-share:focus-visible,
.nr-article-copy:focus-visible,
.nr-article-action:focus-visible {
  border-color: color-mix(in srgb, var(--clr-gold) 55%, transparent);
  color: var(--clr-gold-dark);
  box-shadow: var(--shadow-sm);
  transform: translateY(-1px);
}

.nr-article-action-label,
.nr-article-share-status {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
}

.nr-article-copy.is-copied {
  border-color: var(--clr-gold);
  color: var(--clr-gold-dark);
}

.nr-article-visual {
  min-width: 0;
  margin-left: calc(var(--space-4) * -1);
}

.nr-article-visual img {
  display: block;
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: contain;
  filter: drop-shadow(var(--shadow-md));
}

.nr-article-reading {
  margin-top: var(--space-6);
  padding-top: var(--space-6);
  border-top: 1px solid var(--clr-border);
  color: var(--clr-text);
  font-size: var(--text-base);
  line-height: var(--leading-relaxed);
}

.nr-article-reading > p,
.nr-article-section > p {
  max-width: 70ch;
  margin: 0 0 var(--space-5);
}

.nr-article-reading strong {
  color: var(--clr-primary-800);
  font-weight: var(--weight-extrabold);
}

.nr-article-section {
  scroll-margin-top: calc(var(--header-height) + var(--space-8));
  margin: var(--space-16) 0 0;
}

.nr-article-section:first-of-type {
  margin-top: var(--space-10);
}

.nr-article-section-head {
  display: grid;
  grid-template-columns: 40px minmax(0, 1fr);
  gap: var(--space-4);
  align-items: start;
  margin-bottom: var(--space-5);
}

.nr-article-section-num {
  color: var(--clr-gold-dark);
  font-family: Georgia, "Times New Roman", serif;
  font-size: var(--text-3xl);
  font-weight: var(--weight-bold);
  line-height: 1;
}

.nr-article-section-title {
  margin: 0;
  color: var(--clr-text);
  font-family: Georgia, "Times New Roman", serif;
  font-size: var(--text-3xl);
  font-weight: var(--weight-bold);
  letter-spacing: 0;
  line-height: var(--leading-tight);
  text-wrap: balance;
}

.nr-article-data-card {
  float: right;
  width: min(42%, 360px);
  margin: 0 0 var(--space-6) var(--space-8);
  overflow: hidden;
  border: 1px solid var(--clr-border);
  border-radius: var(--radius-sm);
  background: var(--clr-surface);
  box-shadow: var(--shadow-sm);
}

.nr-article-module-head {
  display: grid;
  gap: var(--space-2);
  padding: var(--space-4) var(--space-5);
  border-bottom: 1px solid var(--clr-border-light);
}

.nr-article-module-label,
.nr-article-callout-eyebrow,
.nr-article-cta-eyebrow {
  color: var(--clr-gold-dark);
  font-size: var(--text-xs);
  font-weight: var(--weight-extrabold);
  letter-spacing: 0;
  text-transform: uppercase;
}

.nr-article-module-title {
  margin: 0;
  color: var(--clr-text);
  font-family: var(--font-display);
  font-size: var(--text-base);
  font-weight: var(--weight-extrabold);
  line-height: var(--leading-tight);
}

.nr-article-data-table-wrap {
  overflow-x: auto;
}

.nr-article-data-table {
  width: 100%;
  min-width: 330px;
  border-collapse: collapse;
  font-size: var(--text-xs);
}

.nr-article-data-table th,
.nr-article-data-table td {
  padding: var(--space-3);
  border-bottom: 1px solid var(--clr-border-light);
  text-align: right;
}

.nr-article-data-table th:first-child,
.nr-article-data-table td:first-child {
  text-align: left;
}

.nr-article-data-table thead {
  background: var(--gradient-primary);
}

.nr-article-data-table th {
  color: var(--clr-text-on-dark);
  font-weight: var(--weight-extrabold);
}

.nr-article-data-table td {
  color: var(--clr-text);
  font-family: var(--font-mono);
  font-weight: var(--weight-semibold);
}

.nr-article-pullquote {
  max-width: 70ch;
  margin: var(--space-8) 0;
  padding: var(--space-5) var(--space-6);
  border-left: 3px solid var(--clr-gold);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  background: color-mix(in srgb, var(--clr-gold) 6%, var(--clr-surface));
  color: var(--clr-primary-700);
  font-size: var(--text-lg);
  font-style: italic;
  line-height: var(--leading-normal);
}

.nr-article-pullquote p {
  margin: 0;
}

.nr-article-pullquote strong {
  font-style: normal;
}

.nr-article-exercise-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 0;
  max-width: 70ch;
  margin: var(--space-8) 0;
  border-block: 1px solid var(--clr-border-light);
}

.nr-article-exercise-card {
  display: grid;
  gap: var(--space-3);
  padding: var(--space-5) var(--space-4);
  border-right: 1px solid var(--clr-border-light);
  background: transparent;
}

.nr-article-exercise-card:last-child {
  border-right: 0;
}

.nr-article-exercise-card span {
  display: inline-flex;
  color: var(--clr-gold-dark);
}

.nr-article-exercise-card h3,
.nr-article-practice-card h3 {
  margin: 0;
  color: var(--clr-text);
  font-family: var(--font-display);
  font-size: var(--text-sm);
  font-weight: var(--weight-extrabold);
  line-height: var(--leading-tight);
}

.nr-article-exercise-card p,
.nr-article-practice-card p {
  margin: 0;
  color: var(--clr-text-muted);
  font-size: var(--text-xs);
  line-height: var(--leading-normal);
}

.nr-article-practice-card {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  gap: var(--space-5);
  align-items: center;
  max-width: 70ch;
  margin: var(--space-8) 0;
  padding: var(--space-5);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius-sm);
  background: var(--clr-surface);
  box-shadow: var(--shadow-sm);
}

.nr-article-practice-icon {
  color: var(--clr-primary);
}

.nr-article-practice-card .btn {
  min-height: 44px;
  white-space: nowrap;
}

.nr-article-callout,
.nr-article-calc-card,
.nr-article-check-card {
  max-width: 70ch;
  margin: var(--space-8) 0;
  border: 1px solid var(--clr-border);
  border-radius: var(--radius-sm);
  background: var(--clr-surface);
  box-shadow: var(--shadow-xs);
}

.nr-article-callout {
  display: grid;
  gap: var(--space-3);
  padding: var(--space-5);
}

.nr-article-callout p {
  margin: 0;
  color: var(--clr-text-muted);
  font-size: var(--text-sm);
  line-height: var(--leading-normal);
}

.nr-article-callout a,
.nr-article-footer a {
  color: var(--clr-primary);
  font-weight: var(--weight-extrabold);
  text-decoration: none;
}

.nr-article-callout a:hover,
.nr-article-callout a:focus-visible,
.nr-article-footer a:hover,
.nr-article-footer a:focus-visible {
  text-decoration: underline;
}

.nr-article-calculator {
  display: grid;
  grid-template-columns: 220px minmax(0, 1fr);
  gap: var(--space-6);
  align-items: center;
  padding: var(--space-5);
}

.nr-article-calculator-shell {
  padding: var(--space-4);
  border-radius: var(--radius-sm);
  background: var(--gradient-primary);
  box-shadow: var(--shadow-primary);
}

.nr-article-calc-display {
  height: 54px;
  margin-bottom: var(--space-4);
  border-radius: var(--radius-sm);
  background: color-mix(in srgb, var(--clr-text-on-dark) 10%, transparent);
}

.nr-article-calc-keys {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: var(--space-2);
}

.nr-article-calc-keys span {
  display: grid;
  min-height: 44px;
  place-items: center;
  border-radius: var(--radius-sm);
  background: color-mix(in srgb, var(--clr-surface) 92%, var(--clr-primary-50));
  color: var(--clr-primary-800);
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  font-weight: var(--weight-extrabold);
}

.nr-article-calc-keys span:nth-child(4n),
.nr-article-calc-keys span:last-child {
  background: var(--gradient-gold);
}

.nr-article-calculator-note {
  display: grid;
  gap: var(--space-3);
  color: var(--clr-text-muted);
  font-size: var(--text-sm);
  line-height: var(--leading-normal);
}

.nr-article-calculator-note p {
  margin: 0;
}

.nr-article-trap-list {
  display: grid;
  gap: var(--space-3);
  margin: 0;
  padding: var(--space-5);
  list-style: none;
}

.nr-article-trap-list li {
  display: grid;
  grid-template-columns: 24px minmax(0, 1fr);
  gap: var(--space-3);
  align-items: start;
  color: var(--clr-text-muted);
  font-size: var(--text-sm);
  line-height: var(--leading-normal);
}

.nr-article-trap-list li::before {
  content: "";
  width: 18px;
  height: 18px;
  margin-top: var(--space-1);
  border: 2px solid var(--clr-gold);
  border-radius: var(--radius-full);
  background: var(--clr-gold-50);
}

.nr-article-trap-list strong {
  display: block;
  color: var(--clr-text);
}

.nr-article-cta-card {
  max-width: 70ch;
  margin: var(--space-12) 0 0;
  padding: var(--space-8);
  border-radius: var(--radius-sm);
  background: var(--gradient-hero);
  box-shadow: var(--shadow-xl);
  color: var(--clr-text-on-dark);
}

.nr-article-cta-title {
  max-width: 18ch;
  margin: var(--space-3) 0;
  color: var(--clr-text-on-dark);
  font-family: Georgia, "Times New Roman", serif;
  font-size: var(--text-3xl);
  font-weight: var(--weight-bold);
  line-height: var(--leading-tight);
}

.nr-article-cta-copy {
  max-width: 58ch;
  margin: 0 0 var(--space-6);
  color: color-mix(in srgb, var(--clr-text-on-dark) 78%, transparent);
  font-size: var(--text-base);
  line-height: var(--leading-normal);
}

.nr-article-cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
}

.nr-article-cta-actions .btn-primary {
  min-height: 44px;
  border-color: color-mix(in srgb, var(--clr-gold-light) 44%, transparent);
  background: var(--gradient-gold);
  color: var(--clr-primary-800);
  box-shadow: var(--shadow-gold);
}

.nr-article-ghost-dark {
  min-height: 44px;
  border-color: color-mix(in srgb, var(--clr-text-on-dark) 24%, transparent);
  color: var(--clr-text-on-dark);
}

.nr-article-footer {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: var(--space-4);
  max-width: 70ch;
  margin-top: var(--space-12);
  padding-top: var(--space-6);
  border-top: 1px solid var(--clr-border);
}

.nr-article-reveal {
  opacity: 0;
  transform: translateY(var(--space-5));
  transition:
    opacity var(--motion-reveal),
    transform var(--motion-reveal);
}

.nr-article-reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

@media (max-width: 1060px) {
  .nr-article-layout {
    grid-template-columns: 1fr;
  }

  .nr-article-rail {
    position: relative;
    top: auto;
    display: block;
    padding: 0;
    border-right: 0;
  }

  .nr-article-rail > .nr-article-rail-title,
  .nr-article-rail > .nr-article-toc,
  .nr-article-rail-cta {
    display: none;
  }

  .nr-article-mobile-guide {
    display: block;
    margin-top: var(--space-6);
    padding: var(--space-5) 0 var(--space-4);
    border-top: 1px solid var(--clr-border-light);
    border-bottom: 1px solid var(--clr-border);
  }

  .nr-article-toc {
    display: flex;
    gap: var(--space-3);
    overflow-x: auto;
    padding-bottom: var(--space-2);
  }

  .nr-article-toc a {
    min-width: 220px;
    border-left: 0;
    border-bottom: 2px solid transparent;
  }

  .nr-article-toc a:hover,
  .nr-article-toc a:focus-visible,
  .nr-article-toc a.is-active {
    transform: translateY(-1px);
  }

  .nr-article-hero {
    grid-template-columns: minmax(0, 1fr) 360px;
  }
}

@media (max-width: 720px) {
  .nr-article {
    padding-top: var(--space-7);
  }

  .nr-article-shell {
    width: min(calc(100% - var(--space-6)), 1240px);
  }

  .nr-article-hero {
    grid-template-columns: 1fr;
    gap: var(--space-5);
  }

  .nr-article-hero-copy,
  .nr-article-hero-tools {
    display: contents;
  }

  .nr-article-meta {
    order: 1;
  }

  .nr-article-title {
    order: 2;
    font-size: var(--text-3xl);
    line-height: 1.08;
  }

  .nr-article-meta-row {
    order: 3;
    font-size: var(--text-xs);
  }

  .nr-article-visual {
    order: 4;
    margin-left: 0;
  }

  .nr-article-lead {
    order: 5;
    margin-top: 0;
    font-size: var(--text-base);
  }

  .nr-article-hero-actions {
    order: 6;
  }

  .nr-article-visual img {
    width: min(100%, 330px);
    margin-inline: auto;
  }

  .nr-article-reading {
    margin-top: var(--space-6);
    padding-top: var(--space-6);
  }

  .nr-article-section-head {
    grid-template-columns: 34px minmax(0, 1fr);
  }

  .nr-article-section-num,
  .nr-article-section-title,
  .nr-article-cta-title {
    font-size: var(--text-2xl);
  }

  .nr-article-data-card {
    float: none;
    width: 100%;
    margin: var(--space-6) 0;
  }

  .nr-article-exercise-grid {
    grid-template-columns: 1fr 1fr;
  }

  .nr-article-exercise-card:nth-child(2n) {
    border-right: 0;
  }

  .nr-article-practice-card,
  .nr-article-calculator {
    grid-template-columns: 1fr;
  }

  .nr-article-practice-card .btn {
    width: 100%;
  }
}

@media (max-width: 430px) {
  .nr-article-title {
    font-size: var(--text-2xl);
  }

  .nr-article-exercise-grid {
    grid-template-columns: 1fr;
  }

  .nr-article-exercise-card {
    border-right: 0;
    border-bottom: 1px solid var(--clr-border-light);
  }

  .nr-article-exercise-card:last-child {
    border-bottom: 0;
  }
}

@media (prefers-reduced-motion: reduce) {
  .nr-article-progress span,
  .nr-article-back,
  .nr-article-toc a,
  .nr-article-share,
  .nr-article-copy,
  .nr-article-action,
  .nr-article-reveal {
    transition-duration: 1ms;
  }

  .nr-article-reveal {
    opacity: 1;
    transform: none;
  }
}