/* ============================================================================
   base.css — modern reset, element defaults, shared utilities
   ----------------------------------------------------------------------------
   Contract : docs/architecture.md §8  (mandatory behaviours 1,2,3,4,7,8)
   Visual   : docs/css-style-ruleset.md §3 (type), §10–§11 (accessible contrast)
   Order    : tokens.css → base.css → layout.css → components.css → scenes.css
   ============================================================================ */

/* ============================================================= 1. reset ==== */
*,
*::before,
*::after {
  box-sizing: border-box;
}

* {
  margin: 0;
}

html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  -webkit-tap-highlight-color: transparent;
  scrollbar-width: thin;
  scrollbar-color: var(--c-line) transparent;
}

/* Behaviour 3 — native smooth anchors only when reduced motion is NOT asked for */
@media (prefers-reduced-motion: no-preference) {
  html {
    scroll-behavior: smooth;
  }
}

body {
  min-height: 100vh;
  min-height: 100svh;
  background-color: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-size: var(--fs-body);
  font-weight: 400;
  line-height: var(--lh-body);
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ======================================================= 2. media defaults == */
img,
picture,
video,
canvas {
  display: block;
  max-width: 100%;
}

svg {
  display: block;
}

img,
video {
  height: auto;
}

/* ============================================ 3. form control inheritance === */
input,
button,
textarea,
select {
  font: inherit;
  color: inherit;
  letter-spacing: inherit;
}

button {
  padding: 0;
  border: 0;
  background: none;
  cursor: pointer;
  -webkit-appearance: none;
  appearance: none;
}

textarea {
  resize: vertical;
}

/* =========================================================== 4. typography == */
/* Body ramp: plum text, generous leading, warm cream ground (ruleset §3). */
h1,
h2,
h3,
h4,
h5,
h6 {
  font-family: var(--font-display);
  font-weight: 400;
  line-height: var(--lh-tight);
  color: var(--text);
  text-wrap: balance;
}

h1 { font-size: var(--fs-h1); }
h2 { font-size: var(--fs-h2); }
h3 { font-size: var(--fs-h3); }

p {
  text-wrap: pretty;
}

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

hr {
  height: 1px;
  border: 0;
  background-color: var(--c-line);
}

/* ================================================================ 5. links == */
a {
  color: var(--accent-strong);
  text-decoration-line: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 0.18em;
  text-decoration-color: var(--c-line);
}

/* Behaviour 4 — hover affordances only where a real pointer exists */
@media (hover: hover) and (pointer: fine) {
  a:hover {
    text-decoration-color: currentColor;
  }
}

/* ============================================================ 6. selection == */
::selection {
  background-color: var(--c-blush);
  color: var(--c-ink);
}

/* ============================================================ 7. scrollbar == */
::-webkit-scrollbar {
  width: 10px;
  height: 10px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  border: 3px solid transparent;
  border-radius: var(--r-pill);
  background-color: var(--c-line);
  background-clip: content-box;
}

/* =============================================================== 8. focus === */
/* Behaviour 1 — one global ring; NO rule anywhere may remove it. */
:focus-visible {
  outline: 2px solid var(--focus);
  outline-offset: 3px;
}

/* Behaviour 7 — [hidden] always wins over any display/visibility toggle. */
[hidden] {
  display: none !important;
}

/* =========================================================== 9. utilities == */

/* Section eyebrows / labels (ruleset §3 label row). */
.eyebrow {
  font-family: var(--font-body);
  font-size: var(--fs-label);
  font-weight: 700;
  line-height: 1.4;
  letter-spacing: var(--tracking-label);
  text-transform: uppercase;
  color: var(--accent-strong);
}

/* First focusable element in the document — parked off-canvas until focused. */
.skip-link {
  position: fixed;
  inset-block-start: var(--sp-2);
  inset-inline-start: var(--sp-2);
  z-index: var(--z-overlay);
  padding: var(--sp-2) var(--sp-3);
  border: 1px solid var(--c-line);
  border-radius: var(--r-pill);
  background-color: var(--c-warm-white);
  color: var(--accent-strong);
  box-shadow: var(--shadow-md);
  font-size: var(--fs-sm);
  font-weight: 700;
  text-decoration: none;
  transform: translateY(calc(-100% - var(--sp-4)));
  transition: transform var(--dur-mid) var(--ease-out);
}

.skip-link:focus-visible {
  transform: translateY(0);
}

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

/* Behaviour 8 — opt-in, transient compositing hint. JS adds this class only
   while an element is actually animating (never a blanket will-change). */
.is-animating {
  will-change: transform, opacity;
}

/* ======================================================= 10. reduced motion = */
/* Behaviour 2 — kill transforms / idle float / long transitions, keep short
   opacity transitions (capped at --dur-fast). */
@media (prefers-reduced-motion: reduce) {
  :root {
    --dur-fast: 120ms;
    --dur-mid: 160ms;
    --dur-slow: 200ms;
  }

  *,
  *::before,
  *::after {
    animation-duration: 1ms !important;
    animation-delay: 0ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: var(--dur-fast) !important;
    transition-delay: 0ms !important;
  }

  html {
    scroll-behavior: auto !important;
  }

  /* Parallax layers and idle-drift orbs stop moving entirely. */
  [data-parallax],
  .orb {
    transform: none !important;
    animation: none !important;
  }
}