/* =============================================================================
 *  base.css  —  reset, typography, background field, a11y primitives
 * ========================================================================== */

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

* { margin: 0; padding: 0; }

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--topbar-h) + var(--topbar-gap) + 28px);
  -webkit-tap-highlight-color: transparent;
}

body {
  font-family: var(--font-sans);
  font-size: var(--fs-base);
  line-height: var(--lh-base);
  color: var(--text-mid);
  background: var(--bg-0);
  min-height: 100vh;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  font-feature-settings: "ss01", "cv01", "cv11";
  position: relative;
}

/* The aurora accent field. The WebGL/canvas shader (#bg-shader) layers on top
 * of this in DOM order; if the shader fails, this static field carries the
 * whole look on its own. Solid floor = body background-color (var(--bg-0)). */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: var(--z-shader);
  background:
    var(--grad-aurora),
    linear-gradient(180deg, rgba(255, 255, 255, 0.025) 0%, transparent 26%);
  pointer-events: none;
}

/* faint UI construction grid — postmodern "interface under construction" hint.
 * As ::after (last child) it paints just above the shader: a subtle overlay. */
body::after {
  content: "";
  position: fixed;
  inset: 0;
  z-index: var(--z-shader);
  background-image:
    linear-gradient(var(--bg-grid) 1px, transparent 1px),
    linear-gradient(90deg, var(--bg-grid) 1px, transparent 1px);
  background-size: 64px 64px;
  -webkit-mask-image: radial-gradient(120% 90% at 50% 30%, #000 30%, transparent 80%);
          mask-image: radial-gradient(120% 90% at 50% 30%, #000 30%, transparent 80%);
  pointer-events: none;
  opacity: 0.7;
}

/* ---- headings ------------------------------------------------------- */
h1, h2, h3, h4 {
  font-family: var(--font-display);
  color: var(--text-hi);
  line-height: var(--lh-tight);
  letter-spacing: var(--tracking-tight);
  font-weight: 680;
  text-wrap: balance;
}

p { text-wrap: pretty; }

a {
  color: var(--accent-primary);
  text-decoration: none;
  transition: color var(--dur-fast) var(--ease-out);
}
a:hover { color: var(--accent-tertiary); }

ul, ol { list-style: none; }
img, svg, canvas { display: block; max-width: 100%; }
img { height: auto; }

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

/* ---- monospace utility (terminal traces, measurements, metadata) ---- */
.mono {
  font-family: var(--font-mono);
  font-size: var(--fs-mono);
  letter-spacing: var(--tracking-mono);
  text-transform: uppercase;
  color: var(--text-mono);
  font-weight: 500;
}

/* ---- focus visibility (keyboard users) ------------------------------ */
:focus { outline: none; }
:focus-visible {
  outline: 2px solid var(--accent-primary);
  outline-offset: 3px;
  border-radius: 6px;
}

/* ---- selection ------------------------------------------------------ */
::selection {
  background: hsl(var(--c-primary-h) var(--c-primary-s) 60% / 0.32);
  color: #fff;
}

/* ---- scrollbar ------------------------------------------------------ */
* { scrollbar-width: thin; scrollbar-color: rgba(150,180,230,0.3) transparent; }
*::-webkit-scrollbar { width: 10px; height: 10px; }
*::-webkit-scrollbar-track { background: transparent; }
*::-webkit-scrollbar-thumb {
  background: linear-gradient(var(--accent-primary), var(--accent-secondary));
  border-radius: 999px;
  border: 3px solid transparent;
  background-clip: content-box;
}

/* ---- visually-hidden but available to AT ---------------------------- */
.sr-only {
  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 ------------------------------------------------------ */
.skip-link {
  position: fixed;
  top: 8px; left: 8px;
  z-index: var(--z-toast);
  padding: 10px 16px;
  background: var(--bg-2);
  color: var(--text-hi);
  border: 1px solid var(--glass-border-strong);
  border-radius: var(--r-sm);
  transform: translateY(-150%);
  transition: transform var(--dur-base) var(--ease-out);
}
.skip-link:focus-visible { transform: translateY(0); }

/* ---- text gradient helper (used by headings, kept readable) --------- */
.text-grad {
  background: var(--grad-text);
  background-size: 200% 100%;
  -webkit-background-clip: text;
          background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}

/* ---- noscript fallback notice --------------------------------------- */
.noscript-note {
  position: fixed;
  inset-block-start: 0;
  inset-inline: 0;
  z-index: var(--z-toast);
  margin: 0;
  padding: 14px 20px;
  text-align: center;
  background: var(--bg-2);
  color: var(--text-hi);
  border-bottom: 1px solid var(--glass-border);
  font-size: var(--fs-sm);
}

/* ---- reduced motion: cut everything non-essential ------------------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
}