/* ---------------------------------------------------------------
   Osewa Blog — design tokens (mirrors specs/design-system.md)
   --------------------------------------------------------------- */
:root {
  /* Brand */
  --primary-main: #0D7377;
  --primary-light: #14919B;
  --primary-dark: #0A5C5F;
  --secondary-main: #D4882B;
  --secondary-light: #E8A44E;
  --secondary-dark: #A86B1C;

  /* Semantic */
  --error-main: #C62828;
  --warning-main: #E6890E;
  --success-main: #2E7D32;
  --info-main: #0277BD;

  /* Neutrals */
  --text-primary: #1A1D21;
  --text-secondary: #5F6368;
  --text-disabled: #9CA3AF;
  --bg-default: #F7F8FA;
  --bg-paper: #FFFFFF;
  --divider: #E3E8EE;
  --border-light: #E3E8EE;
  --border-default: #D8DEE4;
  --border-focus: var(--primary-main);

  /* Shadows (blue-tinted, per design system) */
  --shadow-xs: 0 1px 1px rgba(18, 42, 66, 0.04);
  --shadow-sm: 0 1px 1px rgba(18, 42, 66, 0.03), 0 3px 6px rgba(18, 42, 66, 0.02);
  --shadow-md: 0 2px 4px rgba(18, 42, 66, 0.04), 0 6px 12px rgba(18, 42, 66, 0.03);
  --shadow-lg: 0 4px 8px rgba(18, 42, 66, 0.04), 0 12px 24px rgba(18, 42, 66, 0.05);
  --shadow-xl: 0 8px 16px rgba(18, 42, 66, 0.06), 0 20px 40px rgba(18, 42, 66, 0.06);

  /* Radius */
  --radius-sm: 4px;
  --radius-md: 6px;
  --radius-lg: 8px;
  --radius-xl: 10px;

  /* Transitions */
  --t-shorter: 120ms ease;
  --t-short: 150ms ease;
  --t-standard: 200ms ease;

  /* Type */
  --font-sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: "JetBrains Mono", "SF Mono", Menlo, Consolas, monospace;
}

/* ---------------------------------------------------------------
   Reset + base
   --------------------------------------------------------------- */
*, *::before, *::after { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 0.9375rem;
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--bg-default);
}

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

a {
  color: var(--primary-main);
  text-decoration: none;
  transition: color var(--t-shorter);
}
a:hover { color: var(--primary-dark); }

p { margin: 0 0 1.1em; }

h1, h2, h3, h4, h5, h6 {
  margin: 1.6em 0 0.6em;
  color: var(--text-primary);
  font-weight: 600;
  line-height: 1.25;
  letter-spacing: -0.015em;
}

h1 { font-size: 2.25rem; line-height: 1.2; letter-spacing: -0.025em; }
h2 { font-size: 1.625rem; letter-spacing: -0.02em; }
h3 { font-size: 1.25rem; letter-spacing: -0.01em; }
h4 { font-size: 1.05rem; }

ul, ol { padding-left: 1.4em; }
li { margin: 0.25em 0; }

hr {
  border: 0;
  border-top: 1px solid var(--divider);
  margin: 2.5em 0;
}

blockquote {
  margin: 1.5em 0;
  padding: 0.75em 1.25em;
  border-left: 3px solid var(--primary-main);
  background: var(--bg-default);
  color: var(--text-primary);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
}
blockquote p:last-child { margin-bottom: 0; }

code {
  font-family: var(--font-mono);
  font-size: 0.85em;
  background: var(--bg-default);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  padding: 0.1em 0.35em;
}

pre {
  font-family: var(--font-mono);
  font-size: 0.825rem;
  background: var(--bg-paper);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 14px 16px;
  overflow-x: auto;
  box-shadow: var(--shadow-xs);
}
pre code {
  background: transparent;
  border: 0;
  padding: 0;
  font-size: inherit;
}

table {
  width: 100%;
  border-collapse: collapse;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  overflow: hidden;
  margin: 1.5em 0;
  font-size: 0.875rem;
}
thead {
  background: var(--bg-default);
  color: var(--text-secondary);
  text-transform: uppercase;
  font-size: 0.6875rem;
  letter-spacing: 0.06em;
  font-weight: 600;
}
th, td {
  text-align: left;
  padding: 8px 12px;
  border-bottom: 1px solid var(--border-light);
}
tbody tr:last-child td { border-bottom: 0; }
tbody tr:hover { background: var(--bg-default); }

::selection { background: rgba(13, 115, 119, 0.18); }

:focus-visible {
  outline: 2px solid var(--primary-main);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

/* ---------------------------------------------------------------
   Layout
   --------------------------------------------------------------- */
.container {
  width: 100%;
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 24px;
}
.container.narrow { max-width: 720px; }

.site-main { display: block; padding-bottom: 64px; }

/* ---------------------------------------------------------------
   Header
   --------------------------------------------------------------- */
.site-header {
  background: var(--bg-paper);
  border-bottom: 1px solid var(--divider);
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: saturate(140%) blur(8px);
}
.header-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 56px;
  padding-top: 8px;
  padding-bottom: 8px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--text-primary);
  font-weight: 600;
  letter-spacing: -0.01em;
}
.brand:hover { color: var(--text-primary); }

.brand-mark {
  width: 22px;
  height: 22px;
  border-radius: 6px;
  background: linear-gradient(135deg, var(--primary-main) 0%, var(--primary-light) 100%);
  box-shadow: var(--shadow-xs);
  position: relative;
}
.brand-mark::after {
  content: "";
  position: absolute;
  inset: 5px;
  border-radius: 3px;
  background: rgba(255, 255, 255, 0.85);
}
.brand-name { font-size: 0.9375rem; }
.brand-suffix {
  color: var(--text-secondary);
  font-weight: 500;
  font-size: 0.8125rem;
  padding-left: 8px;
  margin-left: 4px;
  border-left: 1px solid var(--divider);
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 6px;
}
.site-nav a {
  color: var(--text-secondary);
  font-size: 0.8125rem;
  font-weight: 500;
  padding: 6px 10px;
  border-radius: var(--radius-md);
  transition: background-color var(--t-shorter), color var(--t-shorter);
}
.site-nav a:hover {
  color: var(--text-primary);
  background-color: var(--bg-default);
}

.lang-switch {
  display: inline-flex;
  align-items: center;
  margin-left: 8px;
  padding-left: 10px;
  border-left: 1px solid var(--divider);
  gap: 2px;
}
.lang-switch a {
  font-size: 0.6875rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  padding: 4px 8px;
  color: var(--text-secondary);
  border-radius: var(--radius-sm);
}
.lang-switch a.active {
  color: var(--primary-main);
  background: rgba(13, 115, 119, 0.08);
}

/* ---------------------------------------------------------------
   Hero / page header
   --------------------------------------------------------------- */
.hero,
.page-header {
  padding: 72px 0 32px;
}

.eyebrow {
  font-size: 0.6875rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--primary-main);
  margin: 0 0 12px;
}

.hero h1,
.page-header h1 {
  font-size: 2.5rem;
  line-height: 1.15;
  letter-spacing: -0.025em;
  margin: 0 0 16px;
  max-width: 22ch;
}
@media (min-width: 720px) {
  .hero h1, .page-header h1 { font-size: 3rem; }
}

.hero-lede {
  font-size: 1.0625rem;
  line-height: 1.55;
  color: var(--text-secondary);
  max-width: 62ch;
  margin: 0;
}

/* ---------------------------------------------------------------
   Post list (cards)
   --------------------------------------------------------------- */
.post-list { padding: 32px 0 64px; }

.cards {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 16px;
  grid-template-columns: 1fr;
}
@media (min-width: 720px) {
  .cards { grid-template-columns: repeat(2, 1fr); }
}

.card {
  background: var(--bg-paper);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-xs);
  transition: border-color var(--t-short), box-shadow var(--t-short), transform var(--t-short);
}
.card:hover {
  border-color: var(--border-default);
  box-shadow: var(--shadow-sm);
}

.card-link {
  display: block;
  padding: 20px;
  color: inherit;
}
.card-link:hover { color: inherit; }

.card-meta {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.75rem;
  color: var(--text-secondary);
  margin-bottom: 12px;
}
.card-tag {
  display: inline-block;
  padding: 2px 8px;
  background: rgba(13, 115, 119, 0.08);
  color: var(--primary-dark);
  border: 1px solid rgba(13, 115, 119, 0.2);
  border-radius: var(--radius-sm);
  font-size: 0.6875rem;
  font-weight: 600;
  letter-spacing: 0.02em;
}

.card-title {
  margin: 0 0 8px;
  font-size: 1.1875rem;
  line-height: 1.3;
  letter-spacing: -0.015em;
  color: var(--text-primary);
}

.card-summary {
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.55;
  margin: 0 0 16px;
}

.card-cta {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--primary-main);
}

.empty-state {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  padding: 48px 0;
  text-align: center;
}

/* ---------------------------------------------------------------
   Single post
   --------------------------------------------------------------- */
.post-header {
  padding: 64px 0 32px;
  border-bottom: 1px solid var(--divider);
  background: var(--bg-paper);
}
.post-header h1 {
  font-size: 2.25rem;
  line-height: 1.18;
  letter-spacing: -0.025em;
  margin: 0 0 16px;
}
@media (min-width: 720px) {
  .post-header h1 { font-size: 2.625rem; }
}

.post-lede {
  font-size: 1.0625rem;
  line-height: 1.55;
  color: var(--text-secondary);
  margin: 0 0 20px;
  max-width: 60ch;
}

.post-byline {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-size: 0.8125rem;
  color: var(--text-secondary);
}
.byline-author { color: var(--text-primary); font-weight: 500; }
.byline-sep { color: var(--text-disabled); }

.post-body {
  padding: 40px 24px 32px;
  background: var(--bg-paper);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-light);
  box-shadow: var(--shadow-xs);
  margin-top: -24px;
  position: relative;
  font-size: 1rem;
  line-height: 1.7;
}
.post-body > :first-child { margin-top: 0; }
.post-body > :last-child { margin-bottom: 0; }

.post-body h2 {
  margin-top: 2em;
  font-size: 1.5rem;
  letter-spacing: -0.02em;
}
.post-body h3 {
  margin-top: 1.6em;
  font-size: 1.1875rem;
}

.post-body img {
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-light);
  margin: 1.5em 0;
}

.post-body figure {
  margin: 1.5em 0;
}
.post-body figure img {
  margin: 0 0 8px;
}
.post-body figcaption {
  font-size: 0.8125rem;
  color: var(--text-secondary);
  text-align: center;
}

.post-body .tldr {
  background: rgba(13, 115, 119, 0.04);
  border: 1px solid rgba(13, 115, 119, 0.18);
  border-radius: var(--radius-lg);
  padding: 16px 20px;
  margin: 24px 0 32px;
}
.post-body .tldr h3 {
  margin: 0 0 8px;
  font-size: 0.6875rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--primary-dark);
  font-weight: 700;
}
.post-body .tldr ul {
  margin: 0;
  padding-left: 1.2em;
}
.post-body .tldr li { margin: 4px 0; }

/* ---------------------------------------------------------------
   Post CTA
   --------------------------------------------------------------- */
.post-cta { margin: 48px auto; }
.cta-card {
  background: linear-gradient(180deg, rgba(13, 115, 119, 0.04) 0%, rgba(13, 115, 119, 0.02) 100%);
  border: 1px solid rgba(13, 115, 119, 0.2);
  border-radius: var(--radius-xl);
  padding: 24px 28px;
  box-shadow: var(--shadow-xs);
}
.cta-card h3 {
  margin: 0 0 8px;
  font-size: 1.125rem;
  letter-spacing: -0.015em;
}
.cta-card p {
  margin: 0;
  color: var(--text-secondary);
  font-size: 0.9375rem;
}

/* ---------------------------------------------------------------
   Footer
   --------------------------------------------------------------- */
.site-footer {
  border-top: 1px solid var(--divider);
  background: var(--bg-paper);
  padding: 24px 0;
  margin-top: 64px;
}
.footer-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  font-size: 0.8125rem;
  color: var(--text-secondary);
}
.footer-brand {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--text-primary);
  font-weight: 600;
}
.footer-meta {
  display: inline-flex;
  align-items: center;
  gap: 16px;
}
.footer-meta a { color: var(--text-secondary); }
.footer-meta a:hover { color: var(--primary-main); }

/* ---------------------------------------------------------------
   Responsive tweaks
   --------------------------------------------------------------- */
@media (max-width: 540px) {
  .hero, .page-header { padding: 48px 0 24px; }
  .hero h1, .page-header h1 { font-size: 2rem; }
  .post-header { padding: 40px 0 24px; }
  .post-body { padding: 28px 20px; }
  .site-nav a { padding: 6px 8px; }
  .brand-suffix { display: none; }
}