/* ============================================================
   screen-01.css — Intro screen
   Matrix rain, Redaction cycling, nav pill, a11y modal.
   ============================================================ */

/* ---- Screen base ---- */
#screen-01 {
  background: var(--color-bg);
  overflow: hidden;
}

/* ---- Matrix canvas ---- */
#matrix-canvas {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
  pointer-events: none;
}

/* ---- Content stack ---- */
.intro-content {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1.75rem;
  text-align: center;
  padding: 80px 32px;
  max-width: 1000px;
  width: 100%;
}

/* ---- Headline — Redaction weight cycling ---- */
.headline-cycling {
  position: relative;
  font-size: clamp(4rem, 8vw, 9rem);
  line-height: 1.0;
  letter-spacing: -0.02em;
  text-align: center;
  width: 100%;
}

/* Invisible sizer span — holds layout at Redaction 100 (sharpest, most regular metrics) */
.weight-sizer {
  display: block;
  visibility: hidden;
  font-family: var(--font-redaction-100);
  font-weight: 400;
  white-space: nowrap;
  color: var(--color-text-primary);
  user-select: none;
}

/* Two cycling layers, absolutely positioned over sizer */
/* JS switches font-family between Redaction10/50/70/100 + controls opacity */
.weight-layer {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  text-align: center;
  font-family: var(--font-redaction-10);   /* starts at most degraded */
  font-weight: 400;
  color: var(--color-text-primary);
  white-space: nowrap;
  will-change: opacity;
}

/* ---- Subtitle ---- */
.intro-subtitle {
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.65;
  color: var(--color-text-muted);  /* #AAAAAA — 8.52:1 on #0A0A0A, WCAG AAA */
  max-width: 500px;
  /* Soft dark halo ensures legibility against the animated matrix background */
  text-shadow:
    0 0 24px rgba(10, 10, 10, 0.95),
    0 0 8px  rgba(10, 10, 10, 0.8);
}

/* ---- Nav pill ---- */
.nav-pill {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  letter-spacing: 0.03em;
  color: var(--color-text-primary);
  border: 1px solid rgba(79, 195, 247, 0.45);
  border-radius: 9999px;
  padding: 0.65rem 1.75rem;
  background: transparent;
  cursor: pointer;
  transition: opacity var(--transition-fast);
}

.nav-pill:hover,
.nav-pill:focus-visible {
  animation: pill-border-pulse 1.5s ease-in-out infinite;
}

@keyframes pill-border-pulse {
  0%, 100% { border-color: rgba(79, 195, 247, 0); }
  50%       { border-color: rgba(79, 195, 247, 1); }
}

.nav-pill:active {
  opacity: 0.7;
  transform: scale(0.97);
  animation: none;
}

/* Disabled while a11y not acknowledged */
.nav-pill[data-locked="true"] {
  opacity: 0.3;
  cursor: default;
  pointer-events: none;
}

@media (prefers-reduced-motion: reduce) {
  .nav-pill:hover,
  .nav-pill:focus-visible {
    animation: none;
    border-color: var(--color-accent-cyan);
  }
}

/* ---- A11y warning pill ---- */
.a11y-warning-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.02em;
  color: var(--color-text-muted);
  padding: 0.45rem 1.1rem;
  border-radius: 9999px;
  border: 1px solid transparent;
  /* gradient border trick */
  background:
    linear-gradient(var(--color-bg), var(--color-bg)) padding-box,
    linear-gradient(90deg, var(--color-warn-magenta), var(--color-warn-yellow)) border-box;
  cursor: pointer;
  transition: color var(--transition-fast);
}

.a11y-warning-pill:hover,
.a11y-warning-pill:focus-visible {
  color: var(--color-text-primary);
}

.a11y-warn-icon { font-size: 0.9em; }

/* ---- Entry animations ---- */
/* All content starts invisible; class .intro-entered triggers the sequence. */
.intro-content .headline-cycling,
.intro-content .intro-subtitle,
.intro-content .nav-pill,
.intro-content .a11y-warning-pill {
  opacity: 0;
}

@keyframes intro-fade-up {
  from { opacity: 0; transform: translateY(10px); }
  to   { opacity: 1; transform: translateY(0); }
}

#screen-01.intro-entered .headline-cycling {
  animation: intro-fade-up 600ms ease-out 300ms both;
}
#screen-01.intro-entered .intro-subtitle {
  animation: intro-fade-up 600ms ease-out 700ms both;
}
#screen-01.intro-entered .nav-pill {
  animation: intro-fade-up 600ms ease-out 1000ms both;
}
#screen-01.intro-entered .a11y-warning-pill {
  animation: intro-fade-up 600ms ease-out 1300ms both;
}

/* ---- Reduced-motion: skip entry animations, show everything ---- */
body.reduced-motion .intro-content .headline-cycling,
body.reduced-motion .intro-content .intro-subtitle,
body.reduced-motion .intro-content .nav-pill,
body.reduced-motion .intro-content .a11y-warning-pill {
  opacity: 1 !important;
  animation: none !important;
  transform: none !important;
}

@media (prefers-reduced-motion: reduce) {
  .intro-content .headline-cycling,
  .intro-content .intro-subtitle,
  .intro-content .nav-pill,
  .intro-content .a11y-warning-pill {
    opacity: 1 !important;
    animation: none !important;
    transform: none !important;
  }
}

/* ================================================================
   A11y modal
   ================================================================ */

.a11y-modal {
  position: fixed;
  inset: 0;
  z-index: var(--z-a11y);
  display: none;           /* JS toggles .open */
  align-items: center;
  justify-content: center;
}

.a11y-modal.open {
  display: flex;
}

.a11y-modal-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(10, 10, 10, 0.88);
  backdrop-filter: blur(6px);
}

.a11y-modal-card {
  position: relative;
  z-index: 1;
  width: calc(100% - 48px);
  max-width: 440px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 36px;
  display: flex;
  flex-direction: column;
  gap: 1.1rem;
}

.a11y-modal.open .a11y-modal-card {
  animation: a11y-card-in 300ms ease-out both;
}

@keyframes a11y-card-in {
  from { transform: scale(0.95) translateY(-6px); opacity: 0; }
  to   { transform: scale(1) translateY(0); opacity: 1; }
}

@media (prefers-reduced-motion: reduce) {
  .a11y-modal.open .a11y-modal-card {
    animation: none;
  }
}

/* Icon */
.a11y-modal-icon {
  font-size: 1.75rem;
  color: var(--color-warn-magenta);
  line-height: 1;
}

/* Heading */
.a11y-modal-heading {
  font-family: var(--font-mono);
  font-size: 0.9rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-text-primary);
}

/* Body copy */
.a11y-modal-body {
  font-family: var(--font-body);
  font-size: 0.875rem;
  line-height: 1.75;
  color: var(--color-text-muted);
}

/* Reduce-motion toggle */
.a11y-reduce-label {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--color-text-muted);
  cursor: pointer;
  user-select: none;
  transition: color var(--transition-fast);
}

.a11y-reduce-label:hover { color: var(--color-text-primary); }

.a11y-reduce-label input[type="checkbox"] {
  width: 14px;
  height: 14px;
  accent-color: var(--color-accent-cyan);
  cursor: pointer;
  flex-shrink: 0;
}

/* Continue button */
.a11y-continue-btn {
  width: 100%;
  padding: 0.7rem 1.5rem;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--color-text-primary);
  border: 1px solid var(--color-accent-cyan);
  border-radius: var(--radius);
  background: transparent;
  cursor: pointer;
  transition:
    background var(--transition-fast),
    color var(--transition-fast);
}

.a11y-continue-btn:hover,
.a11y-continue-btn:focus-visible {
  background: var(--color-accent-cyan);
  color: var(--color-bg);
}

/* Separator */
.a11y-modal-sep {
  border: none;
  border-top: 1px solid var(--color-border);
  margin: 0;
}

/* ================================================================
   Responsive — 768px and below
   ================================================================ */
@media (max-width: 768px) {
  .intro-content {
    gap: 1.4rem;
    padding: 80px 24px 60px;
  }

  .nav-pill {
    font-size: 0.78rem;
    padding: 0.6rem 1.2rem;
  }

  .a11y-warning-pill {
    font-size: 0.68rem;
    text-align: center;
  }

  .a11y-modal-card {
    padding: 28px 24px;
  }
}