/* ==========================================================================
   main.css — Osaigbovo Omere's personal site
   Vanilla CSS, no frameworks. British English spellings used in comments.
   ========================================================================== */

/* --------------------------------------------------------------------------
   0. Custom properties (design tokens)
   -------------------------------------------------------------------------- */
:root {
  /* Colour palette */
  --colour-bg: #010101;
  --colour-bg-elevated: #0a0a0a;
  --colour-bg-subtle: #111111;
  --colour-border: #1e1e1e;
  --colour-border-subtle: #161616;

  --colour-text: #e5e7eb;
  --colour-text-muted: #6b7280;
  --colour-text-faint: #374151;

  --colour-accent: #8b9cf4; /* soft indigo — visible but not garish */
  --colour-accent-dim: #4f5fa8;

  /* Typography */
  --font-sans: "Fira Sans", "Inter", system-ui, -apple-system, sans-serif;
  --font-mono: "Fira Code", "Cascadia Code", "Consolas", monospace;

  --text-base: 1rem; /* 16px */
  --text-sm: 0.875rem; /* 14px */
  --text-xs: 0.75rem; /* 12px */
  --text-lg: 1.125rem;
  --text-xl: 1.25rem;
  --text-2xl: 1.5rem;
  --text-3xl: 1.875rem;

  --leading-tight: 1.25;
  --leading-body: 1.7;
  --leading-loose: 1.9;

  /* Spacing scale */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;

  /* Layout */
  --content-width: 700px;
  --site-padding: var(--space-6);

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;

  /* Border radius */
  --radius-sm: 3px;
  --radius-md: 6px;
}

/* --------------------------------------------------------------------------
   1. Reset & base
   -------------------------------------------------------------------------- */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behaviour: smooth; /* British spelling in property value — but the actual CSS property is scroll-behavior */
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
}

body {
  background-colour: var(--colour-bg); /* comment intentionally British */
  background-color: var(--colour-bg);
  color: var(--colour-text);
  font-family: var(--font-sans);
  font-size: var(--text-base);
  line-height: var(--leading-body);
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  /* Prevent layout shift from scrollbar appearing */
  overflow-y: scroll;
}

/* Improve default focus outline for keyboard navigation */
:focus-visible {
  outline: 2px solid var(--colour-accent);
  outline-offset: 3px;
  border-radius: var(--radius-sm);
}

img,
video {
  max-width: 100%;
  height: auto;
  display: block;
}

/* --------------------------------------------------------------------------
   2. Typography baseline
   -------------------------------------------------------------------------- */
h1,
h2,
h3,
h4,
h5,
h6 {
  line-height: var(--leading-tight);
  font-weight: 600;
  letter-spacing: -0.01em;
  color: var(--colour-text);
}

h1 {
  font-size: var(--text-3xl);
}
h2 {
  font-size: var(--text-2xl);
}
h3 {
  font-size: var(--text-xl);
}
h4 {
  font-size: var(--text-lg);
}

p {
  max-width: 65ch; /* comfortable reading line length */
}

a {
  color: var(--colour-text);
  text-decoration: underline;
  text-decoration-colour: var(--colour-text-faint);
  text-decoration-color: var(--colour-text-faint);
  text-underline-offset: 3px;
  transition:
    color var(--transition-fast),
    text-decoration-color var(--transition-fast);
}

a:hover,
a:focus-visible {
  color: var(--colour-accent);
  text-decoration-colour: var(--colour-accent);
  text-decoration-color: var(--colour-accent);
}

strong,
b {
  font-weight: 600;
}
em,
i {
  font-style: italic;
}

small {
  font-size: var(--text-sm);
  color: var(--colour-text-muted);
}

hr {
  border: none;
  border-top: 1px solid var(--colour-border);
  margin: var(--space-8) 0;
}

/* --------------------------------------------------------------------------
   3. Layout utilities
   -------------------------------------------------------------------------- */
.container {
  width: 100%;
  max-width: var(--content-width);
  margin-inline: auto;
  padding-inline: var(--site-padding);
}

main {
  flex: 1; /* push footer to bottom */
  width: 100%;
  max-width: var(--content-width);
  margin-inline: auto;
  padding: var(--space-12) var(--site-padding);
}

/* --------------------------------------------------------------------------
   4. Site header & navigation
   -------------------------------------------------------------------------- */
.site-header {
  border-bottom: 1px solid var(--colour-border-subtle);
  padding: var(--space-5) var(--site-padding);
}

.site-nav {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  width: 100%;
  max-width: var(--content-width);
  margin-inline: auto;
  gap: var(--space-6);
}

.site-title {
  font-size: var(--text-base);
  font-weight: 600;
  letter-spacing: -0.01em;
  text-decoration: none;
  color: var(--colour-text);
  white-space: nowrap;
}

.site-title:hover {
  color: var(--colour-accent);
}

.nav-links {
  list-style: none;
  display: flex;
  gap: var(--space-6);
}

.nav-links a {
  font-size: var(--text-sm);
  color: var(--colour-text-muted);
  text-decoration: none;
  letter-spacing: 0.03em;
  text-transform: lowercase;
  transition: color var(--transition-fast);
}

.nav-links a:hover,
.nav-links a[aria-current] {
  color: var(--colour-text);
}

/* --------------------------------------------------------------------------
   5. Site footer
   -------------------------------------------------------------------------- */
.site-footer {
  border-top: 1px solid var(--colour-border-subtle);
  padding: var(--space-6) var(--site-padding);
  margin-top: var(--space-16);
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--space-4);
  width: 100%;
  max-width: var(--content-width);
  margin-inline: auto;
}

.footer-copy {
  font-size: var(--text-sm);
  color: var(--colour-text-muted);
  max-width: none;
}

.footer-links {
  display: flex;
  gap: var(--space-5);
  flex-wrap: wrap;
}

.footer-links a {
  font-size: var(--text-sm);
  color: var(--colour-text-muted);
  text-decoration: none;
  letter-spacing: 0.02em;
  transition: color var(--transition-fast);
}

.footer-links a:hover {
  color: var(--colour-accent);
}

/* --------------------------------------------------------------------------
   6. Homepage — hero & recent posts
   -------------------------------------------------------------------------- */
.hero {
  margin-bottom: var(--space-12);
}

.hero-greeting {
  font-size: var(--text-xl);
  line-height: var(--leading-tight);
  margin-bottom: var(--space-4);
  max-width: none;
}

.hero-greeting strong {
  color: var(--colour-text);
}

.hero-sub {
  color: var(--colour-text-muted);
  margin-bottom: var(--space-6);
}

.focus-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  padding: 0;
  border-left: 2px solid var(--colour-border);
  padding-left: var(--space-5);
  margin-top: var(--space-6);
}

.focus-list li {
  color: var(--colour-text-muted);
  font-size: var(--text-sm);
  letter-spacing: 0.01em;
}

.focus-list li::before {
  content: "—  ";
  color: var(--colour-text-faint);
}

/* Recent posts section */
.recent-posts {
  margin-top: var(--space-12);
}

.section-label {
  font-size: var(--text-xs);
  font-weight: 500;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--colour-text-muted);
  margin-bottom: var(--space-5);
}

.post-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.post-item {
  display: flex;
  align-items: baseline;
  gap: var(--space-4);
  padding: var(--space-3) 0;
  border-bottom: 1px solid var(--colour-border-subtle);
}

.post-item:first-child {
  border-top: 1px solid var(--colour-border-subtle);
}

.post-date {
  font-size: var(--text-xs);
  color: var(--colour-text-muted);
  white-space: nowrap;
  font-variant-numeric: tabular-nums;
  min-width: 80px;
  flex-shrink: 0;
}

.post-title {
  font-size: var(--text-sm);
  color: var(--colour-text);
  text-decoration: none;
  flex: 1;
  transition: color var(--transition-fast);
}

.post-title:hover {
  color: var(--colour-accent);
}

.archive-link-wrap {
  margin-top: var(--space-6);
  max-width: none;
}

.archive-link {
  font-size: var(--text-sm);
  color: var(--colour-text-muted);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.archive-link:hover {
  color: var(--colour-accent);
}

/* --------------------------------------------------------------------------
   7. About page
   -------------------------------------------------------------------------- */
.about-page {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  padding-top: var(--space-8);
}

.about-logo {
  width: 120px;
  height: 120px;
  border-radius: 50%;
  object-fit: cover;
  margin-bottom: var(--space-6);
  border: 2px solid var(--colour-border);
}

.about-tagline {
  font-size: var(--text-lg);
  color: var(--colour-text-muted);
  max-width: 40ch;
  line-height: var(--leading-loose);
}

.about-content {
  margin-top: var(--space-10);
  text-align: left;
  width: 100%;
}

/* --------------------------------------------------------------------------
   8. Blog archive (list layout)
   -------------------------------------------------------------------------- */
.page-title {
  font-size: var(--text-2xl);
  margin-bottom: var(--space-10);
}

.year-group {
  margin-bottom: var(--space-10);
}

.year-label {
  font-size: var(--text-xs);
  font-weight: 500;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--colour-text-muted);
  margin-bottom: var(--space-4);
}

.archive-list {
  list-style: none;
  display: flex;
  flex-direction: column;
}

.archive-item {
  display: grid;
  /* date | title | category */
  grid-template-columns: 70px 1fr auto;
  align-items: baseline;
  gap: var(--space-4);
  padding: var(--space-3) 0;
  border-bottom: 1px solid var(--colour-border-subtle);
}

.archive-item:first-child {
  border-top: 1px solid var(--colour-border-subtle);
}

.archive-date {
  font-size: var(--text-xs);
  color: var(--colour-text-muted);
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
}

.archive-title {
  font-size: var(--text-sm);
  color: var(--colour-text);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.archive-title:hover {
  color: var(--colour-accent);
}

.archive-category {
  font-size: var(--text-xs);
  color: var(--colour-text-muted);
  text-transform: lowercase;
  letter-spacing: 0.04em;
  white-space: nowrap;
}

/* --------------------------------------------------------------------------
   9. Single post layout
   -------------------------------------------------------------------------- */
.single-post {
  /* inherits main's max-width */
}

.post-header {
  margin-bottom: var(--space-10);
  padding-bottom: var(--space-6);
  border-bottom: 1px solid var(--colour-border-subtle);
}

.post-heading {
  font-size: clamp(var(--text-2xl), 5vw, var(--text-3xl));
  line-height: 1.2;
  margin-bottom: var(--space-4);
  letter-spacing: -0.02em;
}

.post-meta {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-2);
  font-size: var(--text-sm);
  color: var(--colour-text-muted);
}

.meta-sep {
  color: var(--colour-text-faint);
}

.post-category {
  color: var(--colour-text-muted);
  font-size: var(--text-xs);
  letter-spacing: 0.05em;
  text-transform: lowercase;
}

.reading-time {
  font-variant-numeric: tabular-nums;
}

.post-footer {
  margin-top: var(--space-12);
  padding-top: var(--space-6);
  border-top: 1px solid var(--colour-border-subtle);
}

.back-link {
  font-size: var(--text-sm);
  color: var(--colour-text-muted);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.back-link:hover {
  color: var(--colour-accent);
}

/* --------------------------------------------------------------------------
   10. Prose — rich text content styles
   -------------------------------------------------------------------------- */
.prose {
  /* Flow spacing for all direct children */
  --flow-space: var(--space-5);
}

.prose > * + * {
  margin-top: var(--flow-space);
}

.prose h2,
.prose h3,
.prose h4 {
  --flow-space: var(--space-8);
  letter-spacing: -0.01em;
}

.prose h2 {
  font-size: var(--text-2xl);
}
.prose h3 {
  font-size: var(--text-xl);
}
.prose h4 {
  font-size: var(--text-lg);
}

.prose p {
  line-height: var(--leading-body);
}

.prose ul,
.prose ol {
  padding-left: var(--space-6);
}

.prose li + li {
  margin-top: var(--space-2);
}

.prose a {
  color: var(--colour-accent);
  text-decoration-colour: var(--colour-accent-dim);
  text-decoration-color: var(--colour-accent-dim);
}

.prose a:hover {
  text-decoration-colour: var(--colour-accent);
  text-decoration-color: var(--colour-accent);
}

.prose blockquote {
  border-left: 3px solid var(--colour-border);
  padding-left: var(--space-5);
  color: var(--colour-text-muted);
  font-style: italic;
  margin: var(--space-8) 0;
}

.prose blockquote p {
  margin-top: 0;
}

/* --------------------------------------------------------------------------
   11. Code & pre blocks
   -------------------------------------------------------------------------- */
code {
  font-family: var(--font-mono);
  font-size: 0.875em;
  background-color: var(--colour-bg-elevated);
  padding: 0.15em 0.4em;
  border-radius: var(--radius-sm);
  color: var(--colour-text);
}

pre {
  background-color: var(--colour-bg-elevated);
  border: 1px solid var(--colour-border);
  border-radius: var(--radius-md);
  padding: var(--space-5) var(--space-6);
  overflow-x: auto;
  line-height: 1.6;
  margin: var(--space-6) 0;
}

pre code {
  background: transparent;
  padding: 0;
  border-radius: 0;
  font-size: var(--text-sm);
}

/* --------------------------------------------------------------------------
   12. Tables — horizontal rules only, no vertical borders
   -------------------------------------------------------------------------- */
table {
  width: 100%;
  border-collapse: collapse;
  font-size: var(--text-sm);
  margin: var(--space-6) 0;
}

thead {
  border-bottom: 2px solid var(--colour-border);
}

th {
  text-align: left;
  font-weight: 600;
  padding: var(--space-3) var(--space-4);
  color: var(--colour-text);
  letter-spacing: 0.02em;
}

td {
  padding: var(--space-3) var(--space-4);
  color: var(--colour-text-muted);
  border-bottom: 1px solid var(--colour-border-subtle);
}

tbody tr:last-child td {
  border-bottom: none;
}

/* --------------------------------------------------------------------------
   13. Poetry — preserve line breaks exactly as authored
   -------------------------------------------------------------------------- */
.poem {
  white-space: pre-wrap;
  font-family: var(--font-sans);
  line-height: var(--leading-loose);
  color: var(--colour-text);
  font-size: var(--text-base);
  max-width: 55ch;
}

/* --------------------------------------------------------------------------
   14. Responsive adjustments
   -------------------------------------------------------------------------- */
@media (max-width: 640px) {
  :root {
    --site-padding: var(--space-4);
  }

  main {
    padding-top: var(--space-8);
    padding-bottom: var(--space-8);
  }

  .archive-item {
    grid-template-columns: 60px 1fr;
    grid-template-rows: auto auto;
  }

  .archive-category {
    grid-column: 2;
    grid-row: 2;
    margin-top: -var(--space-1);
  }

  .footer-inner {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-3);
  }

  .post-item {
    flex-direction: column;
    gap: var(--space-1);
  }

  .post-date {
    min-width: unset;
  }
}

/* --------------------------------------------------------------------------
   15. Print styles
   -------------------------------------------------------------------------- */
@media print {
  body {
    background-color: #fff;
    color: #000;
  }

  .site-header,
  .site-footer,
  .post-footer,
  .back-link {
    display: none;
  }

  a {
    color: #000;
    text-decoration: underline;
  }

  pre,
  code {
    border: 1px solid #ccc;
    background: #f9f9f9;
    color: #000;
  }
}