/* ============================================================
   1. Font faces
   ============================================================ */
@font-face {
  font-family: "Inter";
  font-style: normal;
  font-weight: 100 900;
  font-display: swap;
  src: url("../fonts/InterVariable.woff2") format("woff2");
}
@font-face {
  font-family: "Inter";
  font-style: italic;
  font-weight: 100 900;
  font-display: swap;
  src: url("../fonts/InterVariable-Italic.woff2") format("woff2");
}

/* ============================================================
   2. Design tokens
   ============================================================ */
:root {
  color-scheme: dark;

  --font-family-sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial,
    sans-serif;
  --font-family-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Monaco, Consolas, "Liberation Mono",
    "Courier New", monospace;

  /* Colors — GitHub Dark Default (Primer dark) */
  --color-text: #e6edf3;
  --color-text-secondary: #c9d1d9;
  --color-text-muted: #8b949e;
  --color-background: #0d1117;
  --color-background-subtle: #161b22;
  --color-border: #30363d;
  --color-border-muted: #21262d;
  --color-link: #58a6ff;
  --color-link-visited: #bc8cff;
  --color-accent-emphasis: #1f6feb;
  --color-mark-bg: rgba(187, 128, 9, 0.4);
  --color-pill-bg: rgba(56, 139, 253, 0.15);
  --color-pill-text: #58a6ff;
  --color-pill-bg-hover: rgba(56, 139, 253, 0.25);
  --color-code-bg: rgba(110, 118, 129, 0.4);
  --color-pre-bg: #161b22;
  --color-text-disabled: #484f58;
  --color-on-emphasis: #ffffff;

  /* Layout */
  --page-padding: 42px;
  --content-max-width: 48rem;
  --nav-max-width: 60rem;
  --header-footer-height: 3.5rem;
  --radius-sm: 6px;
  --radius-md: 10px;
  --spacing-unit: 0.5rem;
}

/* ============================================================
   3. Reset & base
   ============================================================ */
*,
*::before,
*::after {
  box-sizing: border-box;
}

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

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
}

body {
  margin: 0;
  padding-top: var(--header-footer-height);
  font-family: var(--font-family-sans);
  font-size: 1rem;
  line-height: 1.6;
  color: var(--color-text);
  background-color: var(--color-background);
  /* Lab-bench dot grid */
  background-image: radial-gradient(circle, rgba(139, 148, 158, 0.1) 1px, transparent 1px);
  background-size: 28px 28px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

::selection {
  background-color: rgba(31, 111, 235, 0.4);
}

:focus-visible {
  outline: 2px solid var(--color-accent-emphasis);
  outline-offset: 2px;
}

.body-container {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

hr {
  border: none;
  border-top: 1px solid var(--color-border);
  margin: calc(var(--spacing-unit) * 4) 0;
}

.main-content {
  flex: 1;
  width: 100%;
  max-width: var(--content-max-width);
  margin: calc(var(--spacing-unit) * 5) auto 0;
  padding: 0 var(--page-padding);
}

/* ============================================================
   4. Typography & links
   ============================================================ */
h1,
h2,
h3,
h4,
h5,
h6 {
  font-weight: 600;
  line-height: 1.3;
  margin: 0;
  color: var(--color-text);
  scroll-margin-top: calc(var(--header-footer-height) + 1rem);
}

a {
  color: var(--color-link);
  text-decoration: none;
}
a:visited {
  color: var(--color-link-visited);
}
a:active {
  color: var(--color-link);
}
a:visited:active {
  color: var(--color-link-visited);
}

/* Links that render in text color until interacted with */
:is(.nav-left a, .nav-center a, .post-title a, .archive-link, .search-result-title a, .read-more, .pagination-link),
:is(.nav-left a, .nav-center a, .post-title a, .archive-link, .search-result-title a, .read-more, .pagination-link):visited {
  color: var(--color-text);
  text-decoration: none;
}

.page-header {
  margin-bottom: calc(var(--spacing-unit) * 4);
}
.page-header h1 {
  font-size: 2rem;
  margin-bottom: var(--spacing-unit);
}
.page-description {
  font-size: 1.1rem;
  color: var(--color-text-muted);
  max-width: 55ch;
}

/* ============================================================
   5. Navigation
   ============================================================ */
.roark-nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-footer-height);
  background-color: rgba(13, 17, 23, 0.95);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--color-border);
  z-index: 1000;
  display: flex;
  justify-content: center;
  padding: 0 var(--page-padding);
}

.nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  width: 100%;
  max-width: var(--nav-max-width);
}

.nav-left,
.nav-right {
  display: flex;
  align-items: center;
  flex: 1;
}
.nav-left {
  gap: calc(var(--spacing-unit) * 3);
}
.nav-left a {
  font-weight: 500;
}
.nav-right {
  justify-content: flex-end;
}
.nav-center {
  flex: 0 1 auto;
  padding: 0 calc(var(--spacing-unit) * 4);
}
.nav-center a.site-title {
  font-weight: 700;
  font-size: 1.5rem;
  white-space: nowrap;
}

/* Mobile nav elements - hidden on desktop */
.nav-mobile-left,
.nav-mobile-right,
.nav-mobile-menu {
  display: none;
}

.nav-right input[type="search"] {
  font-family: inherit;
  font-size: 0.9rem;
  padding: calc(var(--spacing-unit) * 0.8) calc(var(--spacing-unit) * 1.2);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  width: 18rem;
  background-color: var(--color-background);
  color: var(--color-text);
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}
.nav-right input[type="search"]:focus {
  border-color: var(--color-accent-emphasis);
  outline: 0;
  box-shadow: 0 0 0 0.25rem rgba(31, 111, 235, 0.3);
}

/* ============================================================
   6. Post lists & lab-entry cards
   ============================================================ */
.post-list,
.post-list-tag,
.archive-list,
.search-results-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

/* Lab-entry card — shared by home, tag pages, search results */
.post-item,
.search-result-item {
  background-color: var(--color-background-subtle);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  margin-bottom: 1.25rem;
  transition: border-color 0.15s ease;
}
.post-item:last-child,
.search-result-item:last-child {
  margin-bottom: 0;
}

.post-title,
.search-result-title {
  font-size: 1.35rem;
  font-weight: 600;
  line-height: 1.3;
  text-wrap: balance;
  margin-bottom: calc(var(--spacing-unit) * 0.5);
}

.search-result-snippet {
  font-size: 0.95rem;
  color: var(--color-text-secondary);
  margin-top: var(--spacing-unit);
  margin-bottom: 0;
}

.post-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  align-items: baseline;
  font-family: var(--font-family-mono);
  font-size: 0.75rem;
  letter-spacing: 0.05em;
  font-variant-numeric: tabular-nums;
  color: var(--color-text-muted);
  margin-bottom: calc(var(--spacing-unit) * 1.5);
}
/* Self-contained so it renders identically outside a .post-meta row (archive) */
.entry-no {
  font-family: var(--font-family-mono);
  font-size: 0.75rem;
  letter-spacing: 0.05em;
  font-variant-numeric: tabular-nums;
  color: var(--color-pill-text);
}

.post-summary {
  font-size: 0.95rem;
  color: var(--color-text-secondary);
}
.post-summary p {
  margin-top: 0;
  margin-bottom: 1rem;
}

.read-more {
  font-size: 0.9rem;
}

/* ============================================================
   7. Tag pills
   ============================================================ */
.post-tags,
.tag-cloud {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-unit);
}
.post-tags {
  margin-top: calc(var(--spacing-unit) * 2);
}

.post-tags a,
.tag-pill {
  font-family: var(--font-family-mono);
  font-size: 0.75rem;
  color: var(--color-pill-text);
  background-color: var(--color-pill-bg);
  padding: 0.2rem 0.75rem;
  border-radius: 1rem;
  text-decoration: none;
  transition: background-color 0.15s ease, color 0.15s ease;
}
:is(.post-tags a, .tag-pill):visited {
  color: var(--color-pill-text);
  background-color: var(--color-pill-bg);
}

.tag-cloud {
  margin-top: calc(var(--spacing-unit) * 2);
  gap: calc(var(--spacing-unit) * 1.5);
}
.tag-cloud .tag-pill {
  font-size: 0.85rem;
  padding: 0.35rem 1rem;
}
.tag-pill span {
  color: var(--color-text-muted);
  font-size: 0.9em;
  margin-left: calc(var(--spacing-unit) * 0.5);
}

/* ============================================================
   8. Archive
   ============================================================ */
.archive-year-group {
  margin-bottom: calc(var(--spacing-unit) * 4);
}
.archive-year {
  font-size: 1.5rem;
  margin: calc(var(--spacing-unit) * 4) 0 var(--spacing-unit);
  padding-bottom: var(--spacing-unit);
  border-bottom: 1px solid var(--color-border);
}
.archive-year:first-of-type {
  margin-top: 0;
}
.archive-month {
  font-size: 1.2rem;
  margin: calc(var(--spacing-unit) * 3) 0 calc(var(--spacing-unit) * 2);
}

.archive-list li {
  margin-bottom: var(--spacing-unit);
}
/* № | title | date columns; the title wraps, the date stays pinned right */
.archive-post {
  display: flex;
  align-items: baseline;
  gap: calc(var(--spacing-unit) * 2);
}
.archive-post .archive-link {
  flex: 1;
}
.archive-list time,
.archive-date {
  font-family: var(--font-family-mono);
  font-size: 0.75rem;
  letter-spacing: 0.05em;
  font-variant-numeric: tabular-nums;
  color: var(--color-text-muted);
  white-space: nowrap;
}

/* ============================================================
   9. Single post
   ============================================================ */
.post .post-header {
  margin-bottom: calc(var(--spacing-unit) * 4);
  padding-bottom: calc(var(--spacing-unit) * 2);
  border-bottom: 1px solid var(--color-border);
}
.post .post-title {
  font-size: 2.25rem;
  margin-bottom: calc(var(--spacing-unit) * 2);
}

.post-content {
  font-size: 1rem;
  line-height: 1.6;
}

/* GitHub-style markdown typography */
.post-content h1,
.post-content h2,
.post-content h3,
.post-content h4,
.post-content h5,
.post-content h6 {
  margin: 1.5rem 0 1rem;
  font-weight: 600;
  line-height: 1.25;
}
.post-content h1 {
  font-size: 2em;
  padding-bottom: 0.3em;
  border-bottom: 1px solid var(--color-border-muted);
}
.post-content h2 {
  font-size: 1.5em;
  padding-bottom: 0.3em;
  border-bottom: 1px solid var(--color-border-muted);
}
.post-content h3 {
  font-size: 1.25em;
}
.post-content h4 {
  font-size: 1em;
}
.post-content h5 {
  font-size: 0.875em;
}
.post-content h6 {
  font-size: 0.85em;
  color: var(--color-text-muted);
}
.post-content p {
  margin: 0.8em 0;
  text-wrap: pretty;
}
.post-content ul,
.post-content ol {
  margin: 0.8em 0;
  padding-left: 2em;
}
.post-content li + li {
  margin-top: 0.25em;
}
.post-content ul ul,
.post-content ul ol,
.post-content ol ul,
.post-content ol ol {
  margin-bottom: 0;
}
.post-content img {
  max-width: 100%;
  height: auto;
}
.post-content code,
.post-content kbd {
  font-family: var(--font-family-mono);
  font-size: 85%;
  padding: 0.2em 0.4em;
  background-color: var(--color-code-bg);
  border-radius: var(--radius-sm);
}
.post-content pre {
  margin: 0.8em 0;
  padding: 16px;
  background-color: var(--color-pre-bg);
  border-radius: var(--radius-sm);
  overflow-x: auto;
  line-height: 1.45;
}
.post-content pre code {
  padding: 0;
  background-color: transparent;
  border-radius: 0;
}
.post-content blockquote {
  margin: 0.8em 0;
  padding: 0 1em;
  color: var(--color-text-muted);
  border-left: 0.25em solid var(--color-border);
}
.post-content table {
  margin: 0.8em 0;
  border-collapse: collapse;
  border-spacing: 0;
  display: block;
  max-width: 100%;
  overflow-x: auto;
}
.post-content th,
.post-content td {
  padding: 6px 13px;
  border: 1px solid var(--color-border);
}
.post-content th {
  font-weight: 600;
}
.post-content tr:nth-child(2n) {
  background-color: var(--color-background-subtle);
}
.post-content hr {
  height: 0.25em;
  margin: 1.5rem 0;
  padding: 0;
  background-color: var(--color-border);
  border: 0;
}
.post-content a {
  text-decoration: none;
}
.post-content a:visited {
  color: var(--color-link-visited);
}

/* ============================================================
   10. Search
   ============================================================ */
.search-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(13, 17, 23, 0.98);
  backdrop-filter: blur(5px);
  -webkit-backdrop-filter: blur(5px);
  z-index: 2000;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.2s ease, visibility 0.2s ease;
}
.search-overlay.is-active {
  opacity: 1;
  visibility: visible;
}
.search-overlay-content {
  width: 90%;
  max-width: 40rem;
}
.search-overlay-input {
  width: 100%;
  font-size: 1.5rem;
  padding: var(--spacing-unit) 0;
  border: none;
  border-bottom: 2px solid var(--color-text);
  background: transparent;
  outline: none;
  color: var(--color-text);
}
.search-overlay-input:focus {
  border-bottom-color: var(--color-link);
}
.search-overlay-input::placeholder {
  color: var(--color-text-muted);
}
.search-overlay-close {
  position: absolute;
  top: calc(var(--spacing-unit) * 3);
  right: calc(var(--spacing-unit) * 3);
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--spacing-unit);
  color: var(--color-text);
}

.search-section {
  margin-top: calc(var(--spacing-unit) * 3);
}
.search-placeholder,
.search-loading,
.search-error {
  text-align: center;
  color: var(--color-text-muted);
  font-style: italic;
  padding: calc(var(--spacing-unit) * 4) 0;
}
.search-count {
  font-family: var(--font-family-mono);
  font-size: 0.75rem;
  letter-spacing: 0.05em;
  color: var(--color-text-muted);
  margin-bottom: calc(var(--spacing-unit) * 2);
  padding-bottom: calc(var(--spacing-unit) * 2);
  border-bottom: 1px solid var(--color-border);
}
.search-no-results {
  text-align: center;
  padding: calc(var(--spacing-unit) * 4) 0;
}
.search-no-results p:first-child {
  color: var(--color-text-muted);
  font-size: 1.1rem;
  margin-bottom: calc(var(--spacing-unit) * 2);
}

/* ============================================================
   11. Pagination
   ============================================================ */
.pagination {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: calc(var(--spacing-unit) * 8);
  padding-top: calc(var(--spacing-unit) * 4);
  border-top: 1px solid var(--color-border);
  font-size: 0.9rem;
}
.pagination-link {
  font-weight: 500;
}
.pagination-link-disabled {
  color: var(--color-text-disabled);
  cursor: not-allowed;
  font-weight: 500;
  text-decoration: none;
}
.pagination-current {
  display: none;
}

/* ============================================================
   12. Footer
   ============================================================ */
.site-footer {
  margin-top: calc(var(--spacing-unit) * 8);
  height: var(--header-footer-height);
  padding: 0 var(--page-padding);
  border-top: 1px solid var(--color-border);
  text-align: center;
  font-size: 0.9rem;
  color: var(--color-text-muted);
  display: flex;
  align-items: center;
  justify-content: center;
}

/* ============================================================
   13. Utilities
   ============================================================ */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border-width: 0;
}

.skip-link {
  position: absolute;
  top: -100px;
  left: 1rem;
  background: var(--color-accent-emphasis);
  color: var(--color-on-emphasis);
  padding: var(--spacing-unit) calc(var(--spacing-unit) * 2);
  z-index: 1100;
  transition: top 0.2s ease;
  text-decoration: none;
  border-radius: var(--radius-sm);
}
.skip-link:focus {
  top: 1rem;
}

mark {
  background-color: var(--color-mark-bg);
  color: var(--color-text);
  padding: 2px;
  border-radius: 2px;
}

.not-found-mark {
  font-size: 3rem;
  line-height: 1;
  margin-bottom: calc(var(--spacing-unit) * 2);
}

/* ============================================================
   14. Hover — pointer devices only
   ============================================================ */
@media (hover: hover) {
  a:hover {
    text-decoration: underline;
  }

  :is(.nav-left a, .nav-center a, .post-title a, .archive-link, .search-result-title a, .read-more, .pagination-link, .nav-mobile-menu a):hover {
    color: var(--color-link);
    text-decoration: underline;
  }
  :is(.nav-left a, .nav-center a, .post-title a, .archive-link, .search-result-title a, .read-more, .pagination-link, .nav-mobile-menu a):visited:hover {
    color: var(--color-link-visited);
  }

  .post-item:hover,
  .search-result-item:hover {
    border-color: var(--color-text-muted);
  }

  :is(.post-tags a, .tag-pill):hover {
    color: var(--color-pill-text);
    background-color: var(--color-pill-bg-hover);
    text-decoration: none;
  }

  .post-content a:hover {
    text-decoration: underline;
    text-decoration-thickness: 1px;
    text-underline-offset: 3px;
  }
}

/* ============================================================
   15. Touch feedback — coarse pointers only
   ============================================================ */
@media (hover: none) {
  a,
  .hamburger-button,
  .search-icon-button {
    -webkit-tap-highlight-color: rgba(88, 166, 255, 0.2);
  }

  a:active {
    color: var(--color-link);
    text-decoration: underline;
  }
  a:visited:active {
    color: var(--color-link-visited);
  }

  :is(.nav-mobile-menu a, .pagination-link, .archive-link):active {
    background-color: var(--color-background-subtle);
  }

  :is(.post-tags a, .tag-pill):active {
    color: var(--color-pill-text);
    background-color: var(--color-pill-bg-hover);
    text-decoration: none;
  }
}

/* ============================================================
   16. Mobile layout
   ============================================================ */
@media (max-width: 768px) {
  :root {
    --page-padding: calc(var(--spacing-unit) * 3);
  }

  body {
    padding-top: 0;
  }

  .roark-nav {
    position: relative;
    padding: calc(var(--spacing-unit) * 2);
    height: auto;
    border-bottom: 1px solid var(--color-border);
  }

  .nav-container {
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
    width: 100%;
  }

  /* Hide desktop, show mobile nav elements */
  .nav-left,
  .nav-right {
    display: none;
  }
  .nav-mobile-left,
  .nav-mobile-right {
    display: flex;
    align-items: center;
  }
  .nav-center {
    padding: 0;
    flex-grow: 1;
    text-align: center;
  }

  /* Mobile buttons */
  .hamburger-button,
  .search-icon-button {
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-unit);
    width: 44px;
    height: 44px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 5px;
    color: var(--color-text);
  }
  .hamburger-button .bar {
    width: 22px;
    height: 2px;
    background-color: var(--color-text);
    transition: transform 0.2s ease, opacity 0.2s ease;
  }
  .hamburger-button.is-active .bar1 {
    transform: translateY(7px) rotate(45deg);
  }
  .hamburger-button.is-active .bar2 {
    opacity: 0;
  }
  .hamburger-button.is-active .bar3 {
    transform: translateY(-7px) rotate(-45deg);
  }

  /* Mobile menu — anchored to the nav bar, whatever its height */
  .nav-mobile-menu {
    display: none;
    flex-direction: column;
    width: 100%;
    background-color: var(--color-background);
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    border-bottom: 1px solid var(--color-border);
    padding: var(--spacing-unit) 0;
    z-index: 1000;
  }
  .nav-mobile-menu.is-open {
    display: flex;
  }
  .nav-mobile-menu a,
  .nav-mobile-menu a:visited {
    color: var(--color-text);
    text-decoration: none;
    padding: calc(var(--spacing-unit) * 1.5) calc(var(--spacing-unit) * 3);
    text-align: center;
    font-size: 1rem;
    font-weight: 500;
    border-bottom: 1px solid var(--color-border-muted);
  }
  .nav-mobile-menu a:last-child {
    border-bottom: none;
  }

  .main-content {
    margin-top: calc(var(--spacing-unit) * 4);
  }

  .post-item,
  .search-result-item {
    padding: 1.25rem;
  }

  /* Let the credits line wrap without clipping on narrow screens */
  .site-footer {
    height: auto;
    min-height: var(--header-footer-height);
    padding: var(--spacing-unit) var(--page-padding);
  }
}