:root {
  --bg: #f4f7fb;
  --bg-elevated: rgba(255, 255, 255, 0.82);
  --surface: #ffffff;
  --surface-strong: #e7edf5;
  --text: #172033;
  --text-soft: #52607a;
  --border: rgba(23, 32, 51, 0.12);
  --accent: #0b6bcb;
  --accent-strong: #084f98;
  --shadow: 0 18px 40px rgba(20, 37, 63, 0.08);
  --radius: 22px;
  --radius-sm: 14px;
  --container: 72rem;
  --font-body: "Source Serif 4", Georgia, serif;
  --font-ui: "Manrope", "Segoe UI", sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0b1120;
    --bg-elevated: rgba(15, 23, 42, 0.84);
    --surface: #111a2d;
    --surface-strong: #1b2944;
    --text: #edf2ff;
    --text-soft: #b6c1d8;
    --border: rgba(189, 205, 230, 0.14);
    --accent: #7cc4ff;
    --accent-strong: #9fd4ff;
    --shadow: 0 18px 40px rgba(0, 0, 0, 0.3);
  }
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background:
    radial-gradient(circle at top left, rgba(11, 107, 203, 0.12), transparent 32%),
    linear-gradient(180deg, var(--bg) 0%, color-mix(in srgb, var(--bg), #ffffff 8%) 100%);
  color: var(--text);
  font-family: var(--font-body);
  line-height: 1.7;
}

a {
  color: inherit;
}

img {
  max-width: 100%;
}

.container {
  width: min(calc(100% - 2rem), var(--container));
  margin: 0 auto;
}

.site-shell {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.site-main {
  flex: 1;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  backdrop-filter: blur(18px);
  background: var(--bg-elevated);
  border-bottom: 1px solid var(--border);
}

.site-header-inner,
.site-footer-inner,
.section-heading,
.tag-filter-header,
.hero-inner {
  display: flex;
  gap: 1.5rem;
  align-items: center;
  justify-content: space-between;
}

.site-header-inner,
.site-footer-inner {
  padding: 1rem 0;
}

.site-brand {
  text-decoration: none;
  display: inline-flex;
  flex-direction: column;
  gap: 0.15rem;
}

.site-brand-title,
h1,
h2,
h3,
.site-nav a,
.button,
.eyebrow {
  font-family: var(--font-ui);
}

.site-brand-title {
  font-weight: 800;
  letter-spacing: -0.03em;
}

.site-brand-tagline {
  color: var(--text-soft);
  font-size: 0.92rem;
}

.site-nav ul,
.tag-list,
.tag-filter-options {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.site-nav a {
  text-decoration: none;
  color: var(--text-soft);
  font-weight: 700;
}

.site-nav a[aria-current="page"],
.site-nav a:hover,
.text-link,
.post-card h3 a:hover {
  color: var(--accent);
}

.hero,
.page-section {
  padding: 4rem 0;
}

.hero-inner {
  align-items: stretch;
}

.hero-inner > * {
  flex: 1;
}

.hero-panel,
.post-card,
.term-card,
.tag-filter,
.contact-form {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.hero-panel {
  padding: 1.75rem;
}

.hero h1,
.page-header h1,
.article-header h1 {
  font-size: clamp(2.4rem, 6vw, 4.4rem);
  line-height: 1.05;
  letter-spacing: -0.05em;
  margin: 0;
}

.hero-subtitle,
.article-summary {
  font-size: 1.15rem;
  color: var(--text-soft);
}

.hero-copy,
.page-copy,
.contact-note {
  max-width: 68ch;
  color: var(--text-soft);
}

.hero-actions {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
  margin-top: 1.75rem;
}

.button,
.tag-filter-button,
.tag-filter-reset {
  appearance: none;
  border: 1px solid transparent;
  border-radius: 999px;
  cursor: pointer;
  font-weight: 800;
  padding: 0.85rem 1.15rem;
  text-decoration: none;
  transition: 180ms ease;
}

.button-primary,
.tag-filter-button[aria-pressed="true"],
.tag-filter-reset[aria-pressed="true"] {
  background: var(--accent);
  color: #fff;
}

.button-secondary,
.tag-filter-button,
.tag-filter-reset {
  background: var(--surface);
  border-color: var(--border);
  color: var(--text);
}

.button:hover,
.tag-filter-button:hover,
.tag-filter-reset:hover {
  transform: translateY(-1px);
}

.eyebrow {
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: var(--accent);
  font-size: 0.8rem;
  font-weight: 800;
  margin: 0 0 0.75rem;
}

.page-header,
.article-header {
  margin-bottom: 2rem;
}

.post-grid,
.terms-grid {
  display: grid;
  gap: 1.5rem;
  grid-template-columns: repeat(12, minmax(0, 1fr));
}

.post-card,
.filterable-post,
.term-card {
  grid-column: span 12;
}

.post-card {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  padding: 1.5rem;
}

.post-card h3 {
  margin: 0.35rem 0 0.75rem;
  font-size: 1.4rem;
  letter-spacing: -0.03em;
}

.post-card h3 a {
  text-decoration: none;
}

.post-date,
.article-meta,
.site-footer,
.term-count {
  color: var(--text-soft);
}

.tag-list a {
  display: inline-flex;
  padding: 0.35rem 0.75rem;
  border-radius: 999px;
  background: var(--surface-strong);
  text-decoration: none;
  font-family: var(--font-ui);
  font-size: 0.92rem;
}

.tag-filter {
  padding: 1.5rem;
  margin-bottom: 1.5rem;
}

.filterable-post.is-hidden {
  display: none;
}

.article {
  max-width: 52rem;
}

.article-content {
  font-size: 1.1rem;
}

.article-content pre,
.article-content code {
  font-family: "IBM Plex Mono", "SFMono-Regular", monospace;
}

.article-content pre {
  overflow-x: auto;
  padding: 1rem;
  border-radius: var(--radius-sm);
  background: #101827;
  color: #f8fafc;
}

.article-content :where(h2, h3) {
  margin-top: 2.2rem;
  line-height: 1.2;
  letter-spacing: -0.03em;
}

.contact-form {
  padding: 1.5rem;
  max-width: 44rem;
}

.form-grid {
  display: grid;
  gap: 1rem;
}

.form-field {
  display: grid;
  gap: 0.45rem;
}

.form-field label {
  font-family: var(--font-ui);
  font-weight: 700;
}

.form-field input,
.form-field textarea {
  width: 100%;
  border: 1px solid var(--border);
  border-radius: 16px;
  background: var(--surface);
  color: var(--text);
  padding: 0.9rem 1rem;
  font: inherit;
}

.form-field textarea {
  min-height: 12rem;
  resize: vertical;
}

.term-card {
  padding: 1.25rem 1.5rem;
  text-decoration: none;
  display: flex;
  justify-content: space-between;
  gap: 1rem;
}

.site-footer {
  border-top: 1px solid var(--border);
  margin-top: 3rem;
}

@media (min-width: 720px) {
  .post-card,
  .filterable-post,
  .term-card {
    grid-column: span 6;
  }
}

@media (min-width: 1040px) {
  .post-card,
  .filterable-post {
    grid-column: span 4;
  }
}

@media (max-width: 860px) {
  .site-header-inner,
  .site-footer-inner,
  .section-heading,
  .tag-filter-header,
  .hero-inner {
    flex-direction: column;
    align-items: flex-start;
  }
}