/* Base: reset, typography, layout primitives, accessible components. */
*,
*::before,
*::after { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  scroll-padding-top: 4.5rem;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--fg);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: clip;
}

h1, h2, h3, h4 { margin: 0; font-weight: 600; line-height: var(--leading-snug); letter-spacing: -0.015em; text-wrap: balance; }
p { margin: 0; }
p + p { margin-top: 1em; }
img, svg, video { display: block; max-width: 100%; height: auto; }
button, input, select, textarea { font: inherit; color: inherit; }
button { cursor: pointer; border: 0; background: none; padding: 0; }
a { color: inherit; text-decoration: none; }
ul, ol { margin: 0; padding: 0; list-style: none; }
strong { font-weight: 600; }
figure { margin: 0; }
address { font-style: normal; }

:focus-visible {
  outline: 2px solid var(--accent-300);
  outline-offset: 3px;
  border-radius: 2px;
}
.theme-dark :focus-visible { outline-color: var(--accent-300); }

::selection { background: var(--accent-100); color: var(--ink-900); }

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

.skip-link {
  position: fixed; top: 0.75rem; left: 0.75rem;
  z-index: 100;
  padding: 0.75rem 1rem;
  background: var(--paper-50); color: var(--ink-900);
  border-radius: var(--r-sm);
  box-shadow: var(--shadow-2);
  transform: translateY(-200%);
  transition: transform var(--dur-fast) var(--ease-out);
}
.skip-link:focus { transform: none; }

.container {
  width: min(100% - 2 * var(--gutter), var(--container));
  margin-inline: auto;
}

.section { padding-block: var(--section-y); }
.section--tight { padding-block: calc(var(--section-y) * 0.6); }

.eyebrow {
  display: inline-block;
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--fg-muted);
  margin-bottom: var(--s-3);
}

.lede {
  font-size: var(--text-lg);
  line-height: 1.6;
  color: var(--fg-muted);
  max-width: var(--measure);
  text-wrap: pretty;
}
.lede--sm { font-size: var(--text-base); }

.accent-serif {
  font-family: var(--font-serif);
  font-style: italic;
  font-weight: 400;
  letter-spacing: 0;
}

/* Buttons */
.btn {
  --btn-bg: var(--ink-900);
  --btn-fg: var(--paper-50);
  display: inline-flex; align-items: center; justify-content: center; gap: 0.6rem;
  min-height: 3rem;
  padding: 0.85rem 1.4rem;
  border-radius: 999px;
  background: var(--btn-bg); color: var(--btn-fg);
  font-weight: 600; font-size: var(--text-sm); line-height: 1;
  letter-spacing: 0.005em;
  transition: transform var(--dur-fast) var(--ease-out), background-color var(--dur-fast) var(--ease-out), box-shadow var(--dur-fast) var(--ease-out);
  white-space: nowrap;
}
.btn:hover { transform: translateY(-1px); box-shadow: var(--shadow-1); }
.btn:active { transform: translateY(0); }
.btn--paper { --btn-bg: var(--paper-50); --btn-fg: var(--ink-900); }
.btn--ghost { --btn-bg: transparent; --btn-fg: currentColor; box-shadow: inset 0 0 0 1px var(--line-strong); }
.btn--ghost:hover { box-shadow: inset 0 0 0 1px currentColor; }
.btn--lg { min-height: 3.5rem; padding: 1rem 1.75rem; font-size: var(--text-base); }
.btn__arrow { width: 1.1em; height: 1.1em; transition: transform var(--dur-fast) var(--ease-out); }
.btn:hover .btn__arrow { transform: translateX(3px); }

.link-arrow {
  display: inline-flex; align-items: center; gap: 0.45rem;
  font-weight: 600; font-size: var(--text-sm);
  border-bottom: 1px solid transparent;
  transition: border-color var(--dur-fast) var(--ease-out);
}
.link-arrow:hover { border-color: currentColor; }
.link-arrow svg { width: 1em; height: 1em; }

/* Reveal on scroll (progressive enhancement; visible without JS) */
.js [data-reveal] {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity var(--dur-reveal) var(--ease-out), transform var(--dur-reveal) var(--ease-out);
}
.js [data-reveal].is-visible { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: 0.001ms !important; animation-iteration-count: 1 !important; transition-duration: 0.001ms !important; }
  .js [data-reveal] { opacity: 1; transform: none; }
}