/* ------------------------------------------------------------------
   alexpach.com — shared chrome + design tokens
   Every page loads this. Section-specific stylesheets layer on top
   and can override the theme tokens scoped to the section.
   ------------------------------------------------------------------ */

:root {
  /* Color — light theme (homepage default) */
  --color-bg: #fafafa;
  --color-surface: #ffffff;
  --color-surface-alt: #f2f2f4;
  --color-text: #0a0a0b;
  --color-text-muted: #6b6b73;
  --color-text-subtle: #9c9ca3;
  --color-border: #e5e5ea;
  --color-border-strong: #d1d1d6;
  --color-accent: #0a0a0b;
  --color-accent-hover: #3a3a40;
  --color-focus: #0066ff;

  /* Typography */
  --font-sans: -apple-system, BlinkMacSystemFont, "Inter", "Segoe UI",
    Roboto, Helvetica, Arial, sans-serif;
  --font-mono: ui-monospace, "SF Mono", "Cascadia Mono", "Menlo",
    "Consolas", monospace;
  --font-display: var(--font-sans);

  /* Type scale */
  --fs-xs: 0.75rem;
  --fs-sm: 0.875rem;
  --fs-base: 1rem;
  --fs-md: 1.125rem;
  --fs-lg: 1.375rem;
  --fs-xl: 1.75rem;
  --fs-2xl: 2.5rem;
  --fs-3xl: clamp(2.5rem, 6vw, 4.5rem);

  /* Spacing */
  --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;
  --space-9: 6.5rem;

  /* Layout */
  --container-max: 1100px;
  --container-narrow: 760px;
  --header-height: 64px;

  /* Radius */
  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --radius-pill: 999px;

  /* Elevation */
  --shadow-sm: 0 1px 2px rgba(10, 10, 11, 0.04);
  --shadow-md: 0 4px 12px rgba(10, 10, 11, 0.06);
  --shadow-lg: 0 12px 40px rgba(10, 10, 11, 0.08);

  /* Motion */
  --ease-out: cubic-bezier(0.22, 1, 0.36, 1);
  --dur-fast: 120ms;
  --dur-base: 220ms;
  --dur-slow: 380ms;
}

/* ------------------------------------------------------------------
   Reset + base
   ------------------------------------------------------------------ */

*,
*::before,
*::after {
  box-sizing: border-box;
}

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

body {
  margin: 0;
  min-height: 100vh;
  background: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-sans);
  font-size: var(--fs-base);
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

a {
  color: inherit;
  text-decoration: none;
  transition: color var(--dur-fast) var(--ease-out);
}

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

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

h1,
h2,
h3,
h4 {
  font-family: var(--font-display);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.15;
  margin: 0;
}

p {
  margin: 0;
}

button {
  font: inherit;
  cursor: pointer;
  border: 0;
  background: transparent;
  color: inherit;
}

/* ------------------------------------------------------------------
   Layout helpers
   ------------------------------------------------------------------ */

.container {
  width: 100%;
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--space-5);
}

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

.stack > * + * {
  margin-top: var(--space-4);
}

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

/* ------------------------------------------------------------------
   Site header (shared across all pages — rendered by chrome.js)
   ------------------------------------------------------------------ */

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  height: var(--header-height);
  background: color-mix(in srgb, var(--color-bg) 88%, transparent);
  backdrop-filter: saturate(180%) blur(12px);
  -webkit-backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--color-border);
}

.site-header__inner {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-5);
}

.site-header__brand {
  font-weight: 700;
  font-size: var(--fs-md);
  letter-spacing: -0.01em;
  color: var(--color-text);
}

.site-header__brand:hover {
  color: var(--color-text);
}

.site-nav {
  display: flex;
  gap: var(--space-2);
  align-items: center;
}

.site-nav__link {
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-pill);
  font-size: var(--fs-sm);
  font-weight: 500;
  color: var(--color-text-muted);
  transition: background var(--dur-fast) var(--ease-out),
    color var(--dur-fast) var(--ease-out);
}

.site-nav__link:hover {
  color: var(--color-text);
  background: var(--color-surface-alt);
}

.site-nav__link[aria-current="page"] {
  color: var(--color-text);
  background: var(--color-surface-alt);
}

/* ------------------------------------------------------------------
   Section sub-nav (tier-2, rendered only on pages whose section has
   children in SITE)
   ------------------------------------------------------------------ */

.site-subnav {
  position: sticky;
  top: var(--header-height);
  z-index: 40;
  border-bottom: 1px solid var(--color-border);
  background: color-mix(in srgb, var(--color-bg) 92%, transparent);
  backdrop-filter: saturate(180%) blur(10px);
  -webkit-backdrop-filter: saturate(180%) blur(10px);
}

.site-subnav__inner {
  display: flex;
  flex-wrap: nowrap;
  overflow-x: auto;
  gap: var(--space-1);
  padding-block: var(--space-2);
  scrollbar-width: none;
}

.site-subnav__inner::-webkit-scrollbar {
  display: none;
}

.site-subnav__link {
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-md);
  font-size: var(--fs-sm);
  font-weight: 500;
  color: var(--color-text-muted);
  white-space: nowrap;
  transition: background var(--dur-fast) var(--ease-out),
    color var(--dur-fast) var(--ease-out);
}

.site-subnav__link:hover {
  color: var(--color-text);
  background: var(--color-surface-alt);
}

.site-subnav__link[aria-current="page"] {
  color: var(--color-text);
  background: var(--color-surface-alt);
}

/* ------------------------------------------------------------------
   Site footer
   ------------------------------------------------------------------ */

.site-footer {
  margin-top: var(--space-9);
  padding-block: var(--space-6);
  border-top: 1px solid var(--color-border);
  color: var(--color-text-subtle);
  font-size: var(--fs-sm);
}

.site-footer__inner {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
  justify-content: space-between;
  align-items: center;
}

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

/* ------------------------------------------------------------------
   Shared card primitive
   ------------------------------------------------------------------ */

.card {
  display: block;
  padding: var(--space-6);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  transition: transform var(--dur-base) var(--ease-out),
    border-color var(--dur-base) var(--ease-out),
    box-shadow var(--dur-base) var(--ease-out);
}

a.card:hover {
  transform: translateY(-2px);
  border-color: var(--color-border-strong);
  box-shadow: var(--shadow-md);
  color: var(--color-text);
}

/* ------------------------------------------------------------------
   Prefer-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;
  }
}