/* === FRETNERDS — Base Styles === */

:root {
  /* Non-color tokens */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
  --font-serif: 'Lora', Georgia, 'Times New Roman', serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
  --max-width: 720px;
  --max-width-wide: 1080px;
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2.5rem;
  --spacing-2xl: 4rem;
  --radius: 8px;
  --transition: 150ms ease;

  /* Dark theme (default) */
  --color-bg: #0e0e10;
  --color-bg-alpha: rgba(14, 14, 16, 0.9);
  --color-surface: #18181b;
  --color-surface-hover: #1e1e22;
  --color-border: #27272a;
  --color-text: #e4e4e7;
  --color-text-muted: #a1a1aa;
  --color-text-faint: #71717a;
  --color-accent: #f59e0b;
  --color-accent-hover: #fbbf24;
  --color-link: #f59e0b;
  --color-link-hover: #fbbf24;
}

/* Light theme via system preference (no manual override set) */
@media (prefers-color-scheme: light) {
  :root:not([data-theme]) {
    --color-bg: #f8f9fa;
    --color-bg-alpha: rgba(248, 249, 250, 0.9);
    --color-surface: #ffffff;
    --color-surface-hover: #f0f0f2;
    --color-border: #d4d4d8;
    --color-text: #18181b;
    --color-text-muted: #52525b;
    --color-text-faint: #71717a;
    --color-accent: #d97706;
    --color-accent-hover: #b45309;
    --color-link: #d97706;
    --color-link-hover: #b45309;
  }
}

/* Light theme via manual toggle */
[data-theme="light"] {
  --color-bg: #f8f9fa;
  --color-bg-alpha: rgba(248, 249, 250, 0.9);
  --color-surface: #ffffff;
  --color-surface-hover: #f0f0f2;
  --color-border: #d4d4d8;
  --color-text: #18181b;
  --color-text-muted: #52525b;
  --color-text-faint: #71717a;
  --color-accent: #d97706;
  --color-accent-hover: #b45309;
  --color-link: #d97706;
  --color-link-hover: #b45309;
}

/* Dark theme via manual toggle */
[data-theme="dark"] {
  --color-bg: #0e0e10;
  --color-bg-alpha: rgba(14, 14, 16, 0.9);
  --color-surface: #18181b;
  --color-surface-hover: #1e1e22;
  --color-border: #27272a;
  --color-text: #e4e4e7;
  --color-text-muted: #a1a1aa;
  --color-text-faint: #71717a;
  --color-accent: #f59e0b;
  --color-accent-hover: #fbbf24;
  --color-link: #f59e0b;
  --color-link-hover: #fbbf24;
}

/* === Utility === */
.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;
}

/* === Reset === */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  background-color: var(--color-bg);
  color: var(--color-text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

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

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

a:hover {
  color: var(--color-link-hover);
}

/* === Typography === */
h1, h2, h3, h4 {
  font-family: var(--font-sans);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.02em;
  color: var(--color-text);
}

h1 { font-size: clamp(1.75rem, 4vw, 2.5rem); }
h2 { font-size: clamp(1.35rem, 3vw, 1.75rem); margin-top: var(--spacing-xl); }
h3 { font-size: clamp(1.1rem, 2.5vw, 1.35rem); margin-top: var(--spacing-lg); }

p {
  margin-bottom: var(--spacing-md);
}

blockquote {
  border-left: 3px solid var(--color-accent);
  padding-left: var(--spacing-md);
  margin: var(--spacing-lg) 0;
  color: var(--color-text-muted);
  font-style: italic;
}

/* === Layout === */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

.container--wide {
  max-width: var(--max-width-wide);
}

/* === Header === */
.site-header {
  border-bottom: 1px solid var(--color-border);
  padding: var(--spacing-md) 0;
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(8px);
  background: var(--color-bg-alpha);
}

.site-header .container {
  max-width: var(--max-width-wide);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.site-logo {
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--color-text);
  letter-spacing: -0.03em;
  text-transform: uppercase;
}

.site-logo span {
  color: var(--color-accent);
}

.site-nav {
  display: flex;
  gap: var(--spacing-lg);
  align-items: center;
}

.site-nav a {
  color: var(--color-text-muted);
  font-size: 0.875rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  transition: color var(--transition);
}

.site-nav a:hover,
.site-nav a.active {
  color: var(--color-accent);
}

.theme-toggle {
  background: none;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  color: var(--color-text-muted);
  font-size: 1.1rem;
  cursor: pointer;
  padding: 0.3rem 0.5rem;
  line-height: 1;
  transition: color var(--transition), border-color var(--transition);
}

.theme-toggle:hover {
  color: var(--color-accent);
  border-color: var(--color-accent);
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--color-text);
  font-size: 1.5rem;
  cursor: pointer;
  padding: var(--spacing-xs);
}

/* === Main content === */
main {
  flex: 1;
  padding: var(--spacing-xl) 0;
}

/* === Article card (home page) === */
.article-list {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-lg);
}

.article-card {
  position: relative;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: var(--spacing-lg);
  transition: border-color var(--transition), background var(--transition);
  cursor: pointer;
}

.article-card:hover {
  border-color: var(--color-accent);
  background: var(--color-surface-hover);
}

.article-card a {
  color: inherit;
}

.article-card__title a::after {
  content: '';
  position: absolute;
  inset: 0;
  z-index: 1;
}

.article-card__title {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: var(--spacing-sm);
  line-height: 1.3;
}

.article-card__title a:hover {
  color: var(--color-accent);
}

.article-card__meta {
  font-size: 0.8rem;
  color: var(--color-text-faint);
  margin-bottom: var(--spacing-sm);
  display: flex;
  gap: var(--spacing-md);
}

.article-card__excerpt {
  color: var(--color-text-muted);
  font-size: 0.95rem;
  line-height: 1.6;
}

/* === Article page === */
.article-header {
  margin-bottom: var(--spacing-xl);
}

.article-header__title {
  margin-bottom: var(--spacing-sm);
}

.article-header__meta {
  font-size: 0.85rem;
  color: var(--color-text-faint);
  display: flex;
  gap: var(--spacing-md);
  flex-wrap: wrap;
}

.article-body {
  font-family: var(--font-serif);
  font-size: 1.05rem;
  line-height: 1.8;
}

.article-body h2 {
  font-family: var(--font-sans);
  margin-bottom: var(--spacing-md);
}

.article-body h3 {
  font-family: var(--font-sans);
  margin-bottom: var(--spacing-sm);
}

.article-body p {
  margin-bottom: var(--spacing-lg);
}

.article-body ul,
.article-body ol {
  margin-bottom: var(--spacing-lg);
  padding-left: var(--spacing-lg);
}

.article-body li {
  margin-bottom: var(--spacing-sm);
}

.article-body strong {
  color: var(--color-text);
  font-weight: 600;
}

/* === Page header (about) === */
.page-header {
  margin-bottom: var(--spacing-xl);
}

.page-header h1 {
  margin-bottom: var(--spacing-sm);
}

.page-body {
  font-family: var(--font-serif);
  font-size: 1.05rem;
  line-height: 1.8;
}

.page-body p {
  margin-bottom: var(--spacing-lg);
}

/* === Ad slots (hidden by default) === */
.ad-slot {
  display: none;
}

.ad-slot--visible {
  display: block;
  background: var(--color-surface);
  border: 1px dashed var(--color-border);
  border-radius: var(--radius);
  padding: var(--spacing-lg);
  text-align: center;
  color: var(--color-text-faint);
  font-size: 0.8rem;
  margin: var(--spacing-lg) 0;
}

/* === Footer === */
.site-footer {
  border-top: 1px solid var(--color-border);
  padding: var(--spacing-lg) 0;
  margin-top: auto;
}

.site-footer .container {
  max-width: var(--max-width-wide);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--spacing-md);
}

.site-footer__copy {
  font-size: 0.8rem;
  color: var(--color-text-faint);
}

.site-footer__links {
  display: flex;
  gap: var(--spacing-md);
}

.site-footer__links a {
  font-size: 0.8rem;
  color: var(--color-text-faint);
}

.site-footer__links a:hover {
  color: var(--color-accent);
}

/* === Responsive === */
@media (max-width: 640px) {
  .site-nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--color-bg-alpha);
    backdrop-filter: blur(8px);
    border-bottom: 1px solid var(--color-border);
    flex-direction: column;
    padding: var(--spacing-md);
    gap: var(--spacing-md);
  }

  .site-nav.open {
    display: flex;
  }

  .nav-toggle {
    display: block;
  }

  .site-header .container {
    position: relative;
  }

  .site-footer .container {
    flex-direction: column;
    text-align: center;
  }
}