/* =========================================================
   1. DESIGN TOKENS
   ========================================================= */
:root {
  --color-bg: #ffffff;
  --color-bg-alt: #f4f4f5;
  --color-bg-card: #fafafa;
  --color-text: #1b1b1f;
  --color-text-muted: #52525b;
  --color-border: #e4e4e7;
  --color-accent: #4338ca;
  --color-accent-contrast: #ffffff;
  --color-focus: #2563eb;

  --accent-code: #2563eb;
  --accent-yoga: #7c3aed;
  --accent-cooking: #c2410c;
  --accent-travel: #0f766e;

  --font-sans: system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --measure: 65ch;

  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.5rem;
  --space-6: 2rem;
  --space-7: 3rem;
  --space-8: 4.5rem;

  --radius: 0.5rem;
  --shadow-card: 0 1px 2px rgba(0, 0, 0, 0.06), 0 1px 3px rgba(0, 0, 0, 0.08);
  color-scheme: light;
}

:root[data-theme="dark"] {
  --color-bg: #17181c;
  --color-bg-alt: #1f2024;
  --color-bg-card: #232427;
  --color-text: #ececee;
  --color-text-muted: #a3a3ad;
  --color-border: #313136;
  --color-accent: #a5b4fc;
  --color-accent-contrast: #17181c;
  --color-focus: #93c5fd;

  --accent-code: #60a5fa;
  --accent-yoga: #c4b5fd;
  --accent-cooking: #fb923c;
  --accent-travel: #5eead4;

  --shadow-card: 0 1px 2px rgba(0, 0, 0, 0.3), 0 1px 3px rgba(0, 0, 0, 0.4);
  color-scheme: dark;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --color-bg: #17181c;
    --color-bg-alt: #1f2024;
    --color-bg-card: #232427;
    --color-text: #ececee;
    --color-text-muted: #a3a3ad;
    --color-border: #313136;
    --color-accent: #a5b4fc;
    --color-accent-contrast: #17181c;
    --color-focus: #93c5fd;

    --accent-code: #60a5fa;
    --accent-yoga: #c4b5fd;
    --accent-cooking: #fb923c;
    --accent-travel: #5eead4;

    --shadow-card: 0 1px 2px rgba(0, 0, 0, 0.3), 0 1px 3px rgba(0, 0, 0, 0.4);
    color-scheme: dark;
  }
}

/* =========================================================
   2. RESET / BASE
   ========================================================= */
*, *::before, *::after { box-sizing: border-box; }

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

body {
  margin: 0;
  min-height: 100vh;
  display: grid;
  grid-template-rows: auto 1fr auto;
  background: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-sans);
  line-height: 1.6;
  font-size: 1rem;
  -webkit-font-smoothing: antialiased;
}

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

a { color: var(--color-accent); text-decoration-thickness: from-font; }
a:not(.card-link) { text-underline-offset: 0.15em; }

h1, h2, h3 { line-height: 1.25; }
h1 { font-size: clamp(1.75rem, 1.4rem + 1.5vw, 2.5rem); margin: 0 0 var(--space-3); }
h2 { font-size: 1.5rem; margin: 0 0 var(--space-3); }
h3 { font-size: 1.1rem; margin: 0 0 var(--space-2); }
p { margin: 0 0 var(--space-4); }

:focus-visible {
  outline: 3px solid var(--color-focus);
  outline-offset: 2px;
}

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

.skip-link {
  position: absolute;
  left: var(--space-3);
  top: -3rem;
  background: var(--color-accent);
  color: var(--color-accent-contrast);
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius);
  z-index: 100;
  transition: top 0.15s ease;
}
.skip-link:focus {
  top: var(--space-3);
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* =========================================================
   3. LAYOUT (Grid)
   ========================================================= */
.container {
  width: 100%;
  max-width: 1100px;
  margin-inline: auto;
  padding-inline: clamp(1rem, 4vw, 2.5rem);
}

/* --- site-header --- */
site-header {
  display: block;
  position: sticky;
  top: 0;
  z-index: 10;
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
}

.header-inner {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: var(--space-4);
  padding-block: var(--space-3);
}

.site-title {
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--color-text);
  text-decoration: none;
  white-space: nowrap;
}

.primary-nav ul {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-4);
  margin: 0;
  padding: 0;
}

.primary-nav a {
  color: var(--color-text-muted);
  text-decoration: none;
  font-weight: 500;
  padding: var(--space-1) 0;
  border-bottom: 2px solid transparent;
}

.primary-nav a:hover { color: var(--color-text); }

.primary-nav a[aria-current="page"] {
  color: var(--color-text);
  border-bottom-color: var(--color-accent);
}

/* --- main content sections --- */
main { display: block; }

.hero {
  padding-block: var(--space-7) var(--space-6);
}

.hero p {
  color: var(--color-text-muted);
  max-width: var(--measure);
  font-size: 1.15rem;
}

.hero-grid {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: var(--space-6);
  align-items: center;
}

.hero-avatar {
  width: 140px;
  height: 140px;
  border-radius: 50%;
  object-fit: cover;
  border: 3px solid var(--color-border);
}

@media (max-width: 640px) {
  .hero-grid {
    grid-template-columns: 1fr;
    justify-items: center;
    text-align: center;
  }
}

.topic-bio {
  max-width: var(--measure);
  color: var(--color-text-muted);
  font-size: 1.05rem;
}

section { padding-block: var(--space-6); }

/* --- topic grid (home) --- */
.topic-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: var(--space-5);
}

.topic-card {
  display: grid;
  grid-template-rows: auto auto 1fr auto;
  gap: var(--space-2);
  padding: var(--space-5);
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-top: 3px solid var(--card-accent, var(--color-accent));
  border-radius: var(--radius);
  box-shadow: var(--shadow-card);
  text-decoration: none;
  color: var(--color-text);
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.topic-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.topic-card .icon {
  width: 2rem;
  height: 2rem;
  color: var(--card-accent, var(--color-accent));
}

.topic-card p {
  margin: 0;
  color: var(--color-text-muted);
}

.topic-card .read-more {
  font-weight: 600;
  color: var(--card-accent, var(--color-accent));
}

.topic-card--code { --card-accent: var(--accent-code); }
.topic-card--yoga { --card-accent: var(--accent-yoga); }
.topic-card--cooking { --card-accent: var(--accent-cooking); }
.topic-card--travel { --card-accent: var(--accent-travel); }

/* --- post list (topic pages) --- */
.post-list {
  display: grid;
  gap: var(--space-4);
  list-style: none;
  margin: 0;
  padding: 0;
}

.post-card {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: var(--space-2) var(--space-4);
  padding: var(--space-4) var(--space-5);
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
}

.post-card time {
  grid-column: 1;
  color: var(--color-text-muted);
  font-size: 0.9rem;
  white-space: nowrap;
}

.post-card .post-title {
  grid-column: 2;
  margin: 0;
  font-size: 1.15rem;
}

.post-card .post-title a {
  color: var(--color-text);
  text-decoration: none;
}
.post-card .post-title a:hover { color: var(--color-accent); }

.post-card .post-excerpt {
  grid-column: 1 / -1;
  margin: 0;
  color: var(--color-text-muted);
}

/* --- article (post page) --- */
.post-article {
  max-width: var(--measure);
}

.post-meta {
  display: flex;
  gap: var(--space-3);
  align-items: center;
  color: var(--color-text-muted);
  font-size: 0.9rem;
  margin-bottom: var(--space-5);
}

.post-tag {
  display: inline-block;
  padding: 0.15rem var(--space-2);
  border-radius: 999px;
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border);
}

.post-article .post-body > * + * { margin-top: var(--space-4); }
.post-article .post-body h2 { margin-top: var(--space-6); }

.back-link {
  display: inline-block;
  margin-block: var(--space-5);
  text-decoration: none;
  font-weight: 600;
}

/* --- site-footer --- */
site-footer {
  display: block;
  border-top: 1px solid var(--color-border);
  background: var(--color-bg-alt);
}

.footer-inner {
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: center;
  gap: var(--space-4);
  padding-block: var(--space-5);
  color: var(--color-text-muted);
  font-size: 0.9rem;
}

.footer-links {
  display: flex;
  gap: var(--space-4);
  list-style: none;
  margin: 0;
  padding: 0;
}

.footer-links a { color: var(--color-text-muted); }
.footer-links a:hover { color: var(--color-text); }

/* --- theme-toggle --- */
theme-toggle button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.25rem;
  height: 2.25rem;
  border-radius: 999px;
  border: 1px solid var(--color-border);
  background: var(--color-bg-card);
  color: var(--color-text);
  cursor: pointer;
}

theme-toggle button:hover { background: var(--color-bg-alt); }
theme-toggle svg { width: 1.1rem; height: 1.1rem; }

/* --- 404 page --- */
.not-found {
  padding-block: var(--space-8);
  text-align: center;
}
.not-found .container { max-width: 40rem; }

/* --- per-topic accent tinting (set via body class) --- */
body.topic-code { --color-accent: var(--accent-code); }
body.topic-yoga { --color-accent: var(--accent-yoga); }
body.topic-cooking { --color-accent: var(--accent-cooking); }
body.topic-travel { --color-accent: var(--accent-travel); }

/* --- responsive: header stacks nav below on narrow screens --- */
@media (max-width: 640px) {
  .header-inner {
    grid-template-columns: 1fr auto;
    grid-template-areas:
      "title toggle"
      "nav nav";
  }
  .site-title { grid-area: title; }
  theme-toggle { grid-area: toggle; }
  .primary-nav { grid-area: nav; }

  .footer-inner {
    grid-template-columns: 1fr;
    text-align: center;
  }
}