:root {
  --tn-yellow: #f1b034;
  --tn-dark: #112f41;
  --tn-text: #1a2433;
  --tn-muted: #5a6878;
  --tn-bg-light: #f8fafc;
  --tn-border: #e2e8f0;
  --font: 'IBM Plex Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}

*, *::before, *::after { box-sizing: border-box; }

html {
  font-size: 16px;
  height: 100%;
}

body {
  font-family: var(--font);
  color: var(--tn-text);
  background: #fff;
  margin: 0;
  line-height: 1.65;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.hub-wrapper,
.article-wrapper {
  flex: 1;
}

a { color: var(--tn-dark); }
a:hover { color: var(--tn-yellow); }

img { max-width: 100%; height: auto; }

/* --- Navigation --- */
.site-nav {
  background: var(--tn-yellow);
  height: 56px;
  display: flex;
  align-items: center;
  padding: 0 24px;
  justify-content: space-between;
}

.site-nav__logo img {
  height: 28px;
  display: block;
}

.site-nav__links {
  display: flex;
  gap: 28px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.site-nav__links a {
  color: var(--tn-dark);
  text-decoration: none;
  font-size: 14px;
  font-weight: 500;
}

.site-nav__links a:hover {
  text-decoration: underline;
}

/* --- Credentials banner --- */
.credentials-banner {
  background: var(--tn-dark);
  color: #fff;
  padding: 0 24px;
  height: 28px;
  display: flex;
  align-items: center;
  justify-content: flex-end;
}

.credentials-banner__text {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 1px;
  text-transform: uppercase;
  color: #8ca5b8;
  text-align: right;
}

.credentials-banner__text .accent {
  color: var(--tn-yellow);
}

.credentials-banner__text .sep {
  color: #3a5568;
  margin: 0 14px;
}

/* --- Hub layout --- */
.hub-wrapper {
  max-width: 1100px;
  margin: 0 auto;
  padding: 48px 24px 80px;
}

.hub-latest {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
  margin-bottom: 56px;
}

.article-card {
  border: 1px solid var(--tn-border);
  border-radius: 6px;
  padding: 20px 22px;
  text-decoration: none;
  color: inherit;
  display: block;
  transition: border-color 0.15s;
}

.article-card:hover {
  border-color: var(--tn-yellow);
}

.article-card__category {
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.6px;
  color: var(--tn-yellow);
  margin-bottom: 8px;
}

.article-card__title {
  font-size: 17px;
  font-weight: 600;
  line-height: 1.35;
  margin: 0 0 10px;
  color: var(--tn-dark);
}

.article-card__date {
  font-size: 13px;
  color: var(--tn-muted);
}

.hub-categories h2 {
  font-size: 13px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.6px;
  color: var(--tn-muted);
  border-bottom: 1px solid var(--tn-border);
  padding-bottom: 8px;
  margin: 40px 0 16px;
}

.hub-categories h2:first-child {
  margin-top: 0;
}

.category-list {
  list-style: none;
  padding: 0;
  margin: 0 0 8px;
}

.category-list li {
  padding: 6px 0;
  border-bottom: 1px solid var(--tn-border);
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 16px;
}

.category-list li:last-child {
  border-bottom: none;
}

.category-list a {
  font-weight: 500;
  font-size: 15px;
  text-decoration: none;
  color: var(--tn-dark);
}

.category-list a:hover {
  color: var(--tn-yellow);
}

.category-list__date {
  font-size: 13px;
  color: var(--tn-muted);
  white-space: nowrap;
}

/* --- Category index pages --- */
.category-page-header {
  margin-bottom: 32px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--tn-border);
}

.category-page-title {
  font-size: 28px;
  font-weight: 600;
  color: var(--tn-dark);
  margin: 0;
}

.category-empty {
  color: var(--tn-muted);
  font-size: 15px;
}

.hub-cat-link {
  color: inherit;
  text-decoration: none;
}

.hub-cat-link:hover {
  color: var(--tn-yellow);
}

/* --- Article layout --- */
.article-wrapper {
  max-width: 820px;
  margin: 0 auto;
  padding: 48px 24px 80px;
}

.article-meta {
  font-size: 13px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--tn-muted);
  margin-bottom: 16px;
}

.article-meta__cat-link {
  color: inherit;
  text-decoration: none;
  font-weight: 600;
}

.article-meta__cat-link:hover {
  color: var(--tn-yellow);
}

.article-h1 {
  font-size: 34px;
  line-height: 1.2;
  font-weight: 600;
  margin: 0 0 20px;
  color: var(--tn-dark);
}

.article-lede {
  font-size: 18px;
  color: var(--tn-muted);
  line-height: 1.6;
  margin: 0 0 28px;
}

/* Quick answer block */
.quick-answer {
  background: var(--tn-bg-light);
  border-left: 4px solid var(--tn-yellow);
  padding: 20px 24px;
  margin: 0 0 36px;
}

.quick-answer__label {
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--tn-muted);
  margin-bottom: 10px;
}

.quick-answer__content {
  font-size: 16px;
  line-height: 1.6;
  margin: 0;
}

.quick-answer__list {
  margin: 0;
  padding-left: 1.25em;
  font-size: 16px;
  line-height: 1.6;
}

.quick-answer__list li {
  margin-bottom: 0.4em;
}

.quick-answer__list li:last-child {
  margin-bottom: 0;
}

/* Table of contents */
.toc {
  background: var(--tn-bg-light);
  border: 1px solid var(--tn-border);
  border-radius: 4px;
  padding: 18px 22px;
  margin: 0 0 36px;
}

.toc__title {
  font-size: 13px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--tn-muted);
  margin: 0 0 10px;
}

.toc ol {
  margin: 0;
  padding-left: 20px;
}

.toc li {
  margin-bottom: 4px;
}

.toc a {
  font-size: 14px;
  color: var(--tn-dark);
  text-decoration: none;
}

.toc a:hover {
  text-decoration: underline;
}

/* Article body */
.article-body h2 {
  font-size: 24px;
  font-weight: 600;
  margin: 44px 0 14px;
  color: var(--tn-dark);
  line-height: 1.3;
}

.article-body h3 {
  font-size: 18px;
  font-weight: 600;
  margin: 28px 0 10px;
  color: var(--tn-dark);
}

.article-body p {
  margin: 0 0 16px;
}

.article-body ul,
.article-body ol {
  padding-left: 22px;
  margin: 0 0 16px;
}

.article-body li {
  margin-bottom: 6px;
}

/* Comparison tables */
.article-body table {
  width: 100%;
  border-collapse: collapse;
  margin: 20px 0 28px;
  font-size: 15px;
}

.article-body th,
.article-body td {
  text-align: left;
  padding: 10px 14px;
  border-bottom: 1px solid var(--tn-border);
  vertical-align: top;
}

.article-body thead th {
  background: var(--tn-dark);
  color: #fff;
  font-weight: 600;
}

.article-body tbody tr:nth-child(even) {
  background: var(--tn-bg-light);
}

.article-body td:is([data-num]),
.article-body th:is([data-num]) {
  font-variant-numeric: tabular-nums;
  font-family: 'IBM Plex Mono', monospace;
}

/* FAQ section */
.faq-section {
  margin-top: 48px;
  border-top: 2px solid var(--tn-border);
  padding-top: 32px;
}

.faq-section__heading {
  font-size: 22px;
  font-weight: 600;
  color: var(--tn-dark);
  margin: 0 0 24px;
}

.faq-item {
  margin-bottom: 28px;
}

.faq-item h3 {
  font-size: 17px;
  font-weight: 600;
  color: var(--tn-dark);
  margin: 0 0 8px;
}

.faq-item p {
  margin: 0;
  font-size: 15px;
  line-height: 1.6;
  color: var(--tn-text);
}

/* About box */
.about-box {
  background: var(--tn-dark);
  color: #c8d6e0;
  border-radius: 6px;
  padding: 28px 32px;
  margin-top: 48px;
}

.about-box h2 {
  color: #fff;
  font-size: 18px;
  font-weight: 600;
  margin: 0 0 12px;
}

.about-box p {
  font-size: 14px;
  margin: 0 0 12px;
  line-height: 1.6;
}

.about-box ul {
  padding-left: 18px;
  margin: 0 0 12px;
}

.about-box li {
  font-size: 14px;
  margin-bottom: 4px;
}

/* Soft CTA */
.soft-cta {
  margin-top: 28px;
  padding-top: 20px;
  border-top: 1px solid rgba(255, 255, 255, 0.15);
  font-size: 14px;
  color: #c8d6e0;
}

.soft-cta a {
  color: var(--tn-yellow);
  text-decoration: none;
  font-weight: 500;
}

.soft-cta a:hover {
  text-decoration: underline;
}

/* Related articles */
.related-section {
  margin-top: 36px;
}

.related-section h2 {
  font-size: 16px;
  font-weight: 600;
  color: var(--tn-muted);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin: 0 0 12px;
}

.related-section ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.related-section li {
  border-bottom: 1px solid var(--tn-border);
  padding: 8px 0;
}

.related-section li:last-child {
  border-bottom: none;
}

.related-section a {
  font-size: 15px;
  font-weight: 500;
  text-decoration: none;
  color: var(--tn-dark);
}

.related-section a:hover {
  color: var(--tn-yellow);
}

@media (max-width: 640px) {
  .site-nav__links {
    gap: 16px;
  }
  .article-h1 {
    font-size: 26px;
  }
  .hub-latest {
    grid-template-columns: 1fr;
  }
}