/* ==========================================================================
   ThetaRev — Base
   Reset, page background, typography and shared elements.
   Values come from theme.css.
   ========================================================================== */

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

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

body {
  margin: 0;
  background: var(--color-paper);
  color: var(--color-ink-soft);
  font-family: var(--font-sans);
  font-size: var(--text-body);
  line-height: var(--leading-body);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

/* Paper grain: a static noise texture laid over the whole page. */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 100;
  pointer-events: none;
  opacity: var(--grain-opacity);
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='240' height='240'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='3' stitchTiles='stitch'/%3E%3CfeColorMatrix values='0 0 0 0 0.11  0 0 0 0 0.15  0 0 0 0 0.22  0 0 0 0.9 0'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}

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

h1,
h2,
h3 {
  margin: 0;
  font-family: var(--font-serif);
  font-weight: var(--font-serif-weight);
  color: var(--color-ink);
  line-height: var(--leading-tight);
  letter-spacing: -0.01em;
}

p {
  margin: 0;
}

em {
  font-style: italic;
}

.label {
  font-family: var(--font-mono);
  font-size: var(--text-micro);
  letter-spacing: var(--tracking-label);
  text-transform: uppercase;
  color: var(--color-mist);
}

/* ---- Links & buttons ----------------------------------------------------- */

a {
  color: inherit;
}

a:focus-visible,
button:focus-visible {
  outline: 1px solid var(--color-accent);
  outline-offset: 4px;
}

/* Quiet text link: underline grows on hover. */
.link-quiet {
  font-size: var(--text-small);
  color: var(--color-ink);
  text-decoration: none;
  letter-spacing: 0.02em;
  background: linear-gradient(var(--color-accent), var(--color-accent)) left bottom / 0 1px no-repeat;
  padding-bottom: 2px;
  transition: background-size var(--duration-quick) var(--ease-calm);
}

.link-quiet:hover {
  background-size: 100% 1px;
}

/* Primary button. */
.button {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: 0.95rem 1.75rem;
  border: 1px solid var(--color-ink);
  border-radius: 999px;
  background: var(--color-ink);
  color: var(--color-paper);
  font-size: var(--text-small);
  letter-spacing: 0.04em;
  text-decoration: none;
  transition:
    background-color var(--duration-quick) var(--ease-calm),
    color var(--duration-quick) var(--ease-calm);
}

.button:hover {
  background: transparent;
  color: var(--color-ink);
}

.button .arrow {
  transition: transform var(--duration-quick) var(--ease-calm);
}

.button:hover .arrow {
  transform: translateX(3px);
}

/* ---- Scroll reveal ------------------------------------------------------- */
/* Only hidden when JavaScript is running (index.html adds the "js" class). */

.js .reveal {
  opacity: 0;
  transform: translateY(12px);
  transition:
    opacity var(--duration-slow) var(--ease-calm),
    transform var(--duration-slow) var(--ease-calm);
}

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

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .js .reveal {
    transform: none;
    transition: opacity var(--duration-quick) linear;
  }
}

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

/* Hidden on screen, still read by screen readers. */
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}