/*
  ARCLO V2 — BASE
  Reset, element defaults, typography, and layout primitives.
*/

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

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

body {
  margin: 0;
  background: var(--color-bg);
  color: var(--color-ink);
  font-family: var(--font-body);
  font-size: var(--text-body);
  line-height: var(--leading-relaxed);
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

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

a {
  color: inherit;
  text-decoration: none;
}

button {
  font: inherit;
  color: inherit;
  background: none;
  border: 0;
  cursor: pointer;
}

ul,
ol {
  margin: 0;
  padding: 0;
  list-style: none;
}

h1,
h2,
h3,
h4,
p,
figure {
  margin: 0;
}

/* ---------------------------------------------------------------
   Typography
--------------------------------------------------------------- */

h1,
h2,
h3,
h4,
.font-display {
  font-family: var(--font-display);
  font-weight: 600;
  letter-spacing: var(--tracking-tight);
  line-height: var(--leading-tight);
  color: var(--color-ink);
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-family: var(--font-body);
  font-size: var(--text-eyebrow);
  font-weight: 600;
  letter-spacing: var(--tracking-wider);
  text-transform: uppercase;
  color: var(--color-ink-muted);
}

.eyebrow::before {
  content: "";
  display: block;
  width: 20px;
  height: 1px;
  background: currentColor;
  opacity: 0.6;
}

.eyebrow--on-dark {
  color: var(--color-on-dark-muted);
}

.lead {
  font-size: var(--text-lead);
  line-height: var(--leading-relaxed);
  color: var(--color-ink-soft);
  max-width: 46ch;
}

.lead--center {
  margin-inline: auto;
  text-align: center;
}

strong {
  font-weight: 600;
}

/* ---------------------------------------------------------------
   Layout primitives
--------------------------------------------------------------- */

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

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

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

.section {
  padding-block: var(--section-pad-y);
  position: relative;
  scroll-margin-top: 88px;
}

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

.section--alt {
  background: var(--color-bg-alt);
}

.section--dark {
  background: var(--color-bg-dark);
  color: var(--color-on-dark);
}

.section--dark h1,
.section--dark h2,
.section--dark h3,
.section--dark h4,
.section--deep h1,
.section--deep h2,
.section--deep h3,
.section--deep h4 {
  color: var(--color-on-dark);
}

.section--deep {
  background: var(--color-bg-dark-deep);
  color: var(--color-on-dark);
}

/* Text-role overrides for components reused inside dark sections.
   Add to this list whenever a light-background component gets reused
   on .section--dark / .section--deep, rather than leaving it to
   inherit navy-on-navy text by accident. */
.section--dark .lead,
.section--deep .lead {
  color: var(--color-on-dark-soft);
}

.section--dark .system-row__outcome,
.section--deep .system-row__outcome {
  color: var(--color-on-dark);
}

.section--dark .system-row__detail,
.section--deep .system-row__detail {
  color: var(--color-on-dark-soft);
}

.section--dark .system-row,
.section--deep .system-row {
  border-color: var(--color-border-on-dark);
}

.section-head {
  max-width: 44rem;
  margin-bottom: var(--space-8);
}

.section-head--center {
  margin-inline: auto;
  text-align: center;
}

/* text-align:center above only centers the H2's own wrapped lines
   (it spans the full section-head width already). .lead is a
   narrower block (max-width: 46ch) with no auto margins of its own,
   so without this it sits flush against the left edge of the
   (already-centered) section-head instead of centering within it —
   reads as "slightly uncentered" under a heading that looks fine. */
.section-head--center .lead {
  margin-inline: auto;
}

.section-head > .eyebrow {
  margin-bottom: var(--space-4);
}

.section-head > h2 {
  margin-bottom: var(--space-4);
}

.hairline {
  border: 0;
  border-top: 1px solid var(--color-border);
  margin: 0;
}

.hairline--on-dark {
  border-top-color: var(--color-border-on-dark);
}

.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;
}

.skip-link {
  position: absolute;
  top: -100%;
  left: var(--space-4);
  z-index: 999;
  background: var(--color-ink);
  color: var(--color-bg);
  padding: var(--space-3) var(--space-5);
  border-radius: var(--radius-md);
  transition: top var(--duration-fast) var(--ease-out);
}

.skip-link:focus {
  top: var(--space-4);
}

/* ---------------------------------------------------------------
   Focus states — every interactive element gets one
--------------------------------------------------------------- */

a:focus-visible,
button:focus-visible,
summary:focus-visible,
input:focus-visible,
textarea:focus-visible {
  outline: 2px solid var(--navy-900);
  outline-offset: 3px;
  border-radius: var(--radius-sm);
}

.section--dark a:focus-visible,
.section--dark button:focus-visible,
.section--deep a:focus-visible,
.section--deep button:focus-visible {
  outline-color: var(--canvas);
}

/* ---------------------------------------------------------------
   Reduced motion
--------------------------------------------------------------- */

@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;
  }
}

/* ---------------------------------------------------------------
   Scroll reveal (progressive enhancement — see js/main.js)
--------------------------------------------------------------- */

[data-reveal] {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity var(--duration-slow) var(--ease-spring),
    transform var(--duration-slow) var(--ease-spring);
}

[data-reveal].is-visible {
  opacity: 1;
  transform: translateY(0);
}

.no-js [data-reveal] {
  opacity: 1;
  transform: none;
}

@media (prefers-reduced-motion: reduce) {
  [data-reveal] {
    opacity: 1;
    transform: none;
    transition: none;
  }
}