@import "tailwindcss";

/* Dark mode: class-based (for @wrksz/themes) */
@custom-variant dark (&:is(.dark));

/* === Design Tokens === */
@theme {
  /* Colors — Light mode defaults */
  --color-canvas: oklch(1 0 0);
  --color-surface: oklch(0.98 0 0);
  --color-ink: oklch(0.08 0 0);
  --color-ink-soft: oklch(0.40 0 0);
  --color-border: oklch(0.92 0 0);
  --color-accent: oklch(0.45 0.18 250);

  /* Code blocks — Light mode */
  --color-code-block: oklch(0.97 0 0);
  --color-code-block-hover: oklch(0.95 0 0);
  --color-code-gutter: oklch(0.50 0 0);
  --color-code-gutter-border: oklch(0.90 0 0);
  --color-code-title-bg: oklch(0.95 0 0);
  --color-code-title-text: oklch(0.40 0 0);
  --color-code-line-highlight: oklch(0.92 0.02 250 / 0.3);
  --color-code-line-highlight-border: oklch(0.45 0.20 250);
  --color-code-mark-bg: oklch(0.90 0.03 250 / 0.4);
  --color-code-copy: oklch(0.40 0 0);
  --color-code-copy-hover: oklch(0.25 0 0);
  --color-code-dot-red: oklch(0.60 0.22 15);
  --color-code-dot-yellow: oklch(0.75 0.18 65);
  --color-code-dot-green: oklch(0.65 0.18 140);
  --radius-code: 0.75rem;

  /* Fonts — override defaults */
  --font-sans: "Fraunces", ui-sans-serif, system-ui, sans-serif;
  --font-serif: "IBM Plex Mono", ui-monospace, monospace;
  --font-mono: "JetBrains Mono", ui-monospace, monospace;

  /* Typography scale */
  --text-xs: 0.75rem; --text-xs--line-height: 1.2;
  --text-sm: 0.875rem; --text-sm--line-height: 1.4;
  --text-base: 1rem; --text-base--line-height: 1.5;
  --text-lg: 1.125rem; --text-lg--line-height: 1.6;
  --text-xl: 1.25rem; --text-xl--line-height: 1.6;
  --text-2xl: 1.5rem; --text-2xl--line-height: 2rem;
  --text-3xl: 1.875rem; --text-3xl--line-height: 2.25rem;
  --text-4xl: 2.25rem; --text-4xl--line-height: 2.5rem;
  --text-5xl: 3rem; --text-5xl--line-height: 1.1;

  /* Shadows */
  --shadow-card: 0 1px 3px oklch(0 0 0 / 0.08);
  --shadow-card-hover: 0 20px 45px -32px oklch(0 0 0 / 0.35), 0 1px 3px oklch(0 0 0 / 0.08);

  /* Animations */
  --animate-fade-in: fade-in 0.3s ease-out;
  --animate-fade-in-up: fade-in-up 0.4s ease-out;
  --animate-slide-up: slide-up 0.5s ease-out;

  @keyframes fade-in {
    from { opacity: 0; }
    to { opacity: 1; }
  }
  @keyframes fade-in-up {
    from { opacity: 0; transform: translateY(12px); }
    to { opacity: 1; transform: translateY(0); }
  }
  @keyframes slide-up {
    from { opacity: 0; transform: translateY(24px); }
    to { opacity: 1; transform: translateY(0); }
  }
}

@layer base {
  html {
    scroll-padding-top: 96px;
  }
  body {
    --header-height: 56px;
    font-family: var(--font-serif);
    font-weight: 400;
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
  }
  h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-sans);
    font-weight: 700;
    line-height: 1.25;
    letter-spacing: -0.015em;
  }
  h1 { line-height: 1.15; letter-spacing: -0.025em; }
  h2 { line-height: 1.2; letter-spacing: -0.02em; }
  code, pre, kbd, samp {
    font-family: var(--font-mono);
    font-feature-settings: 'liga' 1, 'calt' 1;
  }
  a {
    text-underline-offset: 3px;
    text-decoration-thickness: 1px;
    transition: text-decoration-thickness 0.15s ease;
  }
  a:hover {
    text-decoration-thickness: 3px;
  }
  :where(a, button, input, textarea, select, [role="button"]):focus-visible {
    outline: 2px solid var(--color-accent);
    outline-offset: 3px;
    border-radius: 0.375rem;
  }
}

/* === Dark mode token overrides === */
.dark {
  --color-canvas: oklch(0 0 0);
  --color-surface: oklch(0.07 0 0);
  --color-ink: oklch(1 0 0);
  --color-ink-soft: oklch(0.72 0 0);
  --color-border: oklch(0.17 0 0);
  --color-accent: oklch(0.68 0.20 250);

  /* Code blocks — Dark mode */
  --color-code-block: oklch(0.04 0 0);
  --color-code-block-hover: oklch(0.06 0 0);
  --color-code-gutter: oklch(0.30 0 0);
  --color-code-gutter-border: oklch(0.14 0 0);
  --color-code-title-bg: oklch(0.03 0 0);
  --color-code-title-text: oklch(0.55 0 0);
  --color-code-line-highlight: oklch(0.12 0.02 250 / 0.3);
  --color-code-line-highlight-border: oklch(0.68 0.20 250);
  --color-code-mark-bg: oklch(0.10 0.03 250 / 0.4);
  --color-code-copy: oklch(0.60 0 0);
  --color-code-copy-hover: oklch(0.85 0 0);

  --shadow-card: 0 1px 4px oklch(1 0 0 / 0.06);
  --shadow-card-hover: 0 22px 50px -34px oklch(1 0 0 / 0.22), 0 1px 4px oklch(1 0 0 / 0.08);
}

/* === Editorial list surfaces === */
.editorial-hero {
  position: relative;
  overflow: hidden;
  isolation: isolate;
  background:
    radial-gradient(circle at 20% 10%, color-mix(in oklch, var(--color-accent) 10%, transparent), transparent 34%),
    linear-gradient(135deg, color-mix(in oklch, var(--color-surface) 88%, var(--color-canvas)), var(--color-canvas));
}

.editorial-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  opacity: 0.35;
  background-image: radial-gradient(color-mix(in oklch, var(--color-ink) 18%, transparent) 0.5px, transparent 0.5px);
  background-size: 12px 12px;
  mask-image: linear-gradient(135deg, black, transparent 78%);
}

.dark .editorial-hero {
  background:
    radial-gradient(circle at 20% 10%, color-mix(in oklch, var(--color-accent) 14%, transparent), transparent 36%),
    linear-gradient(135deg, color-mix(in oklch, var(--color-surface) 82%, var(--color-canvas)), var(--color-canvas));
}

.dark .editorial-hero::after {
  opacity: 0.22;
}

.empty-state {
  display: grid;
  gap: 0.75rem;
  border: 1px dashed color-mix(in oklch, var(--color-border) 78%, var(--color-ink) 22%);
  border-radius: 1.25rem;
  background: color-mix(in oklch, var(--color-surface) 55%, transparent);
  padding: 2rem;
}

/* === Local prose styles (Tailwind Typography plugin is not installed) === */
.prose {
  color: var(--color-ink);
  font-size: 1rem;
  line-height: 1.75;
  overflow-wrap: break-word;
}

.prose :where(h1, h2, h3, h4, h5, h6) {
  color: var(--color-ink);
  scroll-margin-top: 96px;
}

.prose :where(h1) { margin: 2.75rem 0 1rem; }
.prose :where(h2) { margin: 3rem 0 1rem; padding-bottom: 0.5rem; border-bottom: 1px solid var(--color-border); }
.prose :where(h3) { margin: 2.25rem 0 0.75rem; }
.prose :where(h4, h5, h6) { margin: 1.75rem 0 0.5rem; }
.prose :where(h1, h2, h3, h4, h5, h6):first-child { margin-top: 0; }

.prose :where(p) {
  margin: 1.25rem 0;
  color: var(--color-ink);
}

.article-prose :where(p, ul, ol, blockquote, details, .callout, [data-callout]) {
  max-width: 72ch;
}

.prose :where(a) {
  color: var(--color-accent);
  text-decoration-thickness: 1px;
}

.prose :where(ul, ol) {
  margin: 1.5rem 0;
  padding-left: 1.5rem;
}

.prose :where(li) { margin: 0.45rem 0; padding-left: 0.2rem; }
.prose :where(li)::marker { color: var(--color-accent); }
.prose :where(li > p) { margin: 0.5rem 0; }

.prose :where(blockquote) {
  margin: 2rem 0;
  border-left: 4px solid color-mix(in oklch, var(--color-accent) 45%, var(--color-border));
  border-radius: 0 1rem 1rem 0;
  background: color-mix(in oklch, var(--color-surface) 70%, transparent);
  padding: 0.75rem 1rem 0.75rem 1.25rem;
  color: var(--color-ink-soft);
}

.prose :where(blockquote p) { margin: 0.5rem 0; }

.prose :where(.callout, [data-callout]) {
  margin: 2rem 0;
  border: 1px solid color-mix(in oklch, var(--color-accent) 28%, var(--color-border));
  border-radius: 1rem;
  background: color-mix(in oklch, var(--color-accent) 8%, var(--color-surface));
  padding: 1rem;
}

.prose :where(details) {
  margin: 2rem 0;
  border: 1px solid var(--color-border);
  border-radius: 1rem;
  background: color-mix(in oklch, var(--color-surface) 82%, var(--color-canvas));
  padding: 1rem 1.125rem;
}

.prose :where(summary) {
  cursor: pointer;
  color: var(--color-ink);
  font-weight: 700;
}

.prose :where(details[open] summary) { margin-bottom: 0.75rem; }
.prose :where(details > :last-child) { margin-bottom: 0; }

.prose :where(figure) { margin: 2.5rem 0; }

.prose :where(img) {
  display: block;
  max-width: min(100%, 56rem);
  height: auto;
  margin: 2rem auto;
  border: 1px solid var(--color-border);
  border-radius: 1rem;
  background: var(--color-surface);
  box-shadow: var(--shadow-card);
}

.prose :where(p:has(> img:only-child)) {
  margin: 2.5rem 0 1rem;
}

.article-prose :where(p:has(> img:only-child)) {
  max-width: none;
}

.prose :where(p:has(> img:only-child) + em),
.prose :where(p:has(> img:only-child) + strong) {
  display: block;
  margin-top: -0.5rem;
  text-align: center;
  color: var(--color-ink-soft);
  font-size: 0.875rem;
  line-height: 1.5;
}

.prose :where(figcaption) {
  margin-top: 0.75rem;
  color: var(--color-ink-soft);
  font-size: 0.875rem;
  line-height: 1.5;
  text-align: center;
}

.prose :where(table) {
  width: 100%;
  min-width: 40rem;
  border-collapse: collapse;
  color: var(--color-ink);
}

.prose :where(th, td) {
  border: 1px solid var(--color-border);
  padding: 0.75rem 0.875rem;
  text-align: left;
  vertical-align: top;
}

.prose :where(th) {
  background: var(--color-surface);
  color: var(--color-ink);
  font-weight: 700;
}

.prose :where(tbody tr:nth-child(even)) {
  background: color-mix(in oklch, var(--color-surface) 55%, transparent);
}

.prose :where(pre) {
  max-width: 100%;
  overflow-x: auto;
}

.prose :where(:not(pre) > code) {
  color: var(--color-ink);
}

/* === Code Blocks: Borderless, VS Code Style, Line Numbers === */
[data-rehype-pretty-code-figure] {
  @apply relative overflow-hidden rounded-[var(--radius-code)];
  background-color: var(--color-code-block);
  border: none;
  box-shadow: 0 0 0 1px var(--color-border),
              0 2px 8px oklch(0 0 0 / 0.06);
}
.dark [data-rehype-pretty-code-figure] {
  box-shadow: 0 0 0 1px var(--color-border),
              0 2px 8px oklch(1 0 0 / 0.04);
}

[data-rehype-pretty-code-title] {
  @apply relative flex items-center gap-2.5 px-4 py-2 text-xs;
  background-color: var(--color-code-title-bg);
  border-bottom: 1px solid var(--color-border);
  border-radius: var(--radius-code) var(--radius-code) 0 0;
}
.dark [data-rehype-pretty-code-title] {
  background-color: var(--color-code-title-bg);
}

[data-rehype-pretty-code-title] + pre {
  @apply m-0 rounded-b-[var(--radius-code)] rounded-t-none;
}

[data-rehype-pretty-code-title] .vscode-dots {
  @apply inline-flex gap-[6px] mr-2;
}
[data-rehype-pretty-code-title] .vscode-dots span {
  @apply block h-2.5 w-2.5 rounded-full;
}
[data-rehype-pretty-code-title] .dot-red {
  background-color: var(--color-code-dot-red);
  box-shadow: inset 0 0 0 0.5px oklch(0 0 0 / 0.15);
}
[data-rehype-pretty-code-title] .dot-yellow {
  background-color: var(--color-code-dot-yellow);
  box-shadow: inset 0 0 0 0.5px oklch(0 0 0 / 0.15);
}
[data-rehype-pretty-code-title] .dot-green {
  background-color: var(--color-code-dot-green);
  box-shadow: inset 0 0 0 0.5px oklch(0 0 0 / 0.15);
}

[data-rehype-pretty-code-figure] pre {
  @apply relative overflow-auto p-4;
}

[data-rehype-pretty-code-figure] pre code {
  @apply !bg-transparent font-mono text-[13px] leading-[1.6];
  display: grid;
}

[data-rehype-pretty-code-figure] code[data-line-numbers] {
  counter-reset: line;
}
[data-rehype-pretty-code-figure] code[data-line-numbers] > [data-line]::before {
  counter-increment: line;
  content: counter(line);
  @apply mr-5 inline-block w-4 text-right select-none;
  color: oklch(0.30 0 0);
  @apply text-[11px] font-mono;
}
.dark [data-rehype-pretty-code-figure] code[data-line-numbers] > [data-line]::before {
  color: oklch(0.60 0 0);
}

[data-rehype-pretty-code-figure] [data-line] {
  @apply relative px-2;
  border-left: 2px solid transparent;
}

[data-rehype-pretty-code-figure] [data-highlighted-line] {
  @apply rounded-r-sm;
  background-color: var(--color-code-line-highlight);
  border-left-color: var(--color-code-line-highlight-border);
}

[data-rehype-pretty-code-figure] [data-highlighted-chars] {
  @apply rounded py-0.5 px-1;
  background-color: var(--color-code-mark-bg);
}

[data-rehype-pretty-code-figure] .rehype-pretty-copy {
  @apply absolute right-3 top-3 z-10 flex items-center gap-1 rounded-md border px-2 py-1 text-xs font-medium;
  background-color: oklch(0.97 0 0 / 0.85);
  color: var(--color-code-copy);
  opacity: 0;
  transition: opacity 0.15s ease;
}
.dark [data-rehype-pretty-code-figure] .rehype-pretty-copy {
  background-color: oklch(0.10 0 0 / 0.85);
  color: var(--color-code-copy);
}
[data-rehype-pretty-code-figure]:hover .rehype-pretty-copy,
[data-rehype-pretty-code-figure] .rehype-pretty-copy:focus-visible,
[data-rehype-pretty-code-figure] .rehype-pretty-copy:focus {
  opacity: 1;
}
[data-rehype-pretty-code-figure] .rehype-pretty-copy:hover,
[data-rehype-pretty-code-figure] .rehype-pretty-copy:focus-visible {
  @apply border-current;
  background-color: oklch(0.95 0 0 / 0.95);
  color: var(--color-code-copy-hover);
}
.dark [data-rehype-pretty-code-figure] .rehype-pretty-copy:hover,
.dark [data-rehype-pretty-code-figure] .rehype-pretty-copy:focus-visible {
  background-color: oklch(0.15 0 0 / 0.95);
}
[data-rehype-pretty-code-figure] .rehype-pretty-copy.rehype-pretty-copied {
  @apply border-green-500/50;
  color: oklch(0.55 0.18 140);
}
.dark [data-rehype-pretty-code-figure] .rehype-pretty-copy.rehype-pretty-copied {
  color: oklch(0.70 0.15 140);
}

/* Shiki dual theme token color switching */
code[data-theme*=" "],
code[data-theme*=" "] span {
  color: var(--shiki-light);
}
html.dark code[data-theme*=" "],
html.dark code[data-theme*=" "] span {
  color: var(--shiki-dark);
}

/* === KaTeX dark mode overrides === */
.dark .katex,
.dark .katex * {
  color: currentColor !important;
}
.prose .katex-display {
  color: currentColor !important;
}
.prose .katex-display .katex .base {
  color: currentColor !important;
}
.katex .mfrac .frac-line,
.katex .sqrt .sqrt-line,
.katex .overline .overline-line,
.katex .underline .underline-line {
  border-color: currentColor !important;
}
.katex {
  font-size: 1.1em !important;
}
.katex-display {
  overflow-x: auto;
  overflow-y: hidden;
  max-width: 100%;
  margin: 1.75em 0;
  padding: 0.25rem 0 0.6rem;
  text-align: center;
  -webkit-overflow-scrolling: touch;
}
.katex-display > .katex {
  display: inline-block;
  min-width: max-content;
  text-align: center;
  white-space: nowrap;
}
@media (max-width: 640px) {
  .katex-display {
    margin: 1.25em 0;
    text-align: left;
  }
}
.prose p + .katex-display { margin-top: 0.5em; }
.prose .katex-display + p { margin-bottom: 0.5em; }
.prose p .katex { vertical-align: middle; }
.katex .katex-mathml {
  position: absolute;
  clip: rect(1px, 1px, 1px, 1px);
  padding: 0;
  border: 0;
}

/* === Heading utilities === */
@utility heading-xl {
  font-size: 2.25rem;
  font-weight: 800;
  letter-spacing: -0.025em;
  line-height: 1.1;
}

@utility heading-lg {
  font-size: 1.875rem;
  font-weight: 600;
  letter-spacing: -0.025em;
  line-height: 1.2;
}

@utility heading-md {
  font-size: 1.5rem;
  font-weight: 600;
  letter-spacing: -0.025em;
  line-height: 1.3;
}

@utility heading-sm {
  font-size: 1.25rem;
  font-weight: 600;
  letter-spacing: -0.01em;
  line-height: 1.4;
}

/* === Scroll progress bar (CSS animation-timeline + JS fallback) === */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 2px;
  width: 0%;
  background: var(--color-ink);
  z-index: 9999;
  will-change: width;
}

@keyframes scroll-progress { from { width: 0%; } to { width: 100%; } }
@supports (animation-timeline: scroll()) {
  .scroll-progress {
    width: 0%;
    animation: scroll-progress linear forwards;
    animation-timeline: scroll(root block);
  }
}

/* === Scroll-to-top button === */
.scroll-to-top {
  position: fixed;
  bottom: 24px;
  right: 24px;
  width: 40px;
  height: 40px;
  border: 1px solid var(--color-border);
  border-radius: 50%;
  background: var(--color-canvas);
  color: var(--color-ink);
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transform: translateY(10px);
  pointer-events: none;
  transition: opacity 0.3s ease, transform 0.3s ease, border-color 0.2s ease;
  z-index: 9997;
  will-change: opacity, transform;
}
.scroll-to-top.visible {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}
.scroll-to-top:hover {
  border-color: var(--color-ink);
}

/* === Reading progress vertical bar === */
.reading-progress {
  position: fixed; right: 12px; top: 50%; transform: translateY(-50%);
  width: 3px; height: 60px;
  background: color-mix(in oklch, var(--color-ink) 8%, transparent);
  border-radius: 2px; z-index: 9998; overflow: hidden;
}
.dark .reading-progress {
  background: color-mix(in oklch, var(--color-ink) 15%, transparent);
}
.reading-progress-fill {
  width: 100%;
  height: 0%;
  background: var(--color-ink);
  border-radius: 2px;
}
@keyframes reading-progress { from { height: 0%; } to { height: 100%; } }
@supports (animation-timeline: scroll()) {
  .reading-progress-fill {
    animation: reading-progress linear forwards;
    animation-timeline: scroll(root block);
  }
}

/* === Global transition for theme switch === */
body, body *, [class*="bg-"], [class*="border-"], [class*="text-"] {
  transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease;
}

/* === Reduced motion === */
@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;
  }
  .scroll-progress { display: none; }
  .scroll-to-top { opacity: 0 !important; pointer-events: none !important; }
  .reading-progress { display: none !important; }
}

/* === Focus visible for scroll-to-top === */
.scroll-to-top:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}