/* ==========================================================================
   Reset, base typography, and shared elements.
   ========================================================================== */

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

* { margin: 0; }

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

body {
  min-height: 100svh;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-sans);
  font-size: var(--fs-body);
  line-height: var(--lh-body);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  /* Guards against any child that would otherwise widen the page. */
  overflow-x: hidden;
}

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

button,
input,
textarea,
select { font: inherit; color: inherit; }

h1, h2, h3, h4 {
  font-weight: 600;
  letter-spacing: var(--tracking-tight);
  line-height: var(--lh-snug);
  text-wrap: balance;
}

p { text-wrap: pretty; }

a { color: inherit; }

ul { list-style: none; padding: 0; }

/* Accessibility ----------------------------------------------------------- */

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

.skip-link {
  position: absolute;
  left: var(--sp-4);
  top: var(--sp-4);
  z-index: 200;
  padding: var(--sp-3) var(--sp-4);
  background: var(--ink);
  color: var(--paper);
  border-radius: var(--radius-sm);
  font-size: var(--fs-small);
  font-weight: 500;
  transform: translateY(-150%);
  transition: transform var(--dur) var(--ease);
}
.skip-link:focus-visible { transform: translateY(0); }

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
}

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

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

.section { padding-block: var(--section-y); }

.section__head {
  display: flex;
  flex-direction: column;
  gap: var(--sp-4);
  margin-bottom: clamp(2.5rem, 1.5rem + 3vw, 4.5rem);
}

@media (min-width: 60rem) {
  .section__head {
    flex-direction: row;
    align-items: end;
    justify-content: space-between;
    gap: var(--sp-7);
  }
}

.section__title {
  font-size: var(--fs-h2);
  max-width: 20ch;
}

.section__note {
  color: var(--muted);
  max-width: 34ch;
}

.label {
  display: inline-flex;
  align-items: center;
  gap: var(--sp-2);
  font-family: var(--font-mono);
  font-size: var(--fs-label);
  letter-spacing: var(--tracking-label);
  text-transform: uppercase;
  color: var(--muted);
}

.label::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent);
  flex: none;
}

.label--plain::before { display: none; }

.rule {
  height: 1px;
  background: var(--line);
  border: 0;
}

/* Buttons ----------------------------------------------------------------- */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--sp-2);
  min-height: 3rem;
  padding: 0.8rem 1.5rem;
  border: 1px solid transparent;
  border-radius: 999px;
  font-size: var(--fs-small);
  font-weight: 500;
  text-decoration: none;
  cursor: pointer;
  transition: background var(--dur-fast) var(--ease),
    color var(--dur-fast) var(--ease), border-color var(--dur-fast) var(--ease),
    transform var(--dur-fast) var(--ease);
}

.btn:active { transform: translateY(1px); }

.btn--primary { background: var(--ink); color: var(--paper); }
.btn--primary:hover { background: var(--accent); }

.btn--ghost { border-color: var(--line-strong); color: var(--ink); }
.btn--ghost:hover { border-color: var(--ink); background: var(--surface); }

.btn--light { background: var(--on-dark); color: var(--dark); }
.btn--light:hover { background: #fff; }

.btn--outline-light { border-color: rgba(243, 239, 233, 0.35); color: var(--on-dark); }
.btn--outline-light:hover { border-color: var(--on-dark); background: rgba(243, 239, 233, 0.08); }

.btn__arrow { transition: transform var(--dur) var(--ease); }
.btn:hover .btn__arrow { transform: translateX(3px); }

/* Tags -------------------------------------------------------------------- */

.tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-2);
}

.tag {
  padding: 0.35rem 0.7rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--surface);
  font-size: 0.75rem;
  letter-spacing: 0.01em;
  color: var(--ink-2);
  white-space: nowrap;
}

/* Reveal on scroll -------------------------------------------------------- */

.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity var(--dur-slow) var(--ease),
    transform var(--dur-slow) var(--ease);
  transition-delay: var(--reveal-delay, 0ms);
}

.reveal.is-visible {
  opacity: 1;
  transform: none;
}

/* Anything that must never animate itself out of reach. */
.no-js .reveal { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
  .reveal { opacity: 1; transform: none; }
}