/* ============================================================
   WELCOME SCREEN OVERLAY
   Uses design tokens from tokens.css for strict visual parity.
   ============================================================ */

/* ── FOUC & Scroll Lock ────────────────────────────────── */
html.welcome-active,
html.welcome-active body {
  overflow: hidden !important;
  height: 100vh !important;
  width: 100vw !important;
}

/* Hide other body children while the welcome screen is active.
   This avoids page content flashing or being read by screen readers.
   We exclude script, link, and the welcome overlay itself. */
html.welcome-active body > *:not(script):not(link):not(.welcome-overlay):not(#theme-swatches) {
  opacity: 0 !important;
  pointer-events: none !important;
  user-select: none !important;
}

/* Ensure smooth fade-in of body contents when welcome screen is dismissed */
body > *:not(script):not(link):not(.welcome-overlay) {
  transition: opacity var(--t-slow) var(--ease-out);
}

/* ── Welcome Overlay Base Styles ───────────────────────── */
.welcome-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background-color: var(--color-bg);
  color: var(--color-text-1);
  z-index: 100000; /* Must overlay sidebar & all content */
  
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  padding: var(--s-8) var(--s-7);
  box-sizing: border-box;
  
  opacity: 1;
  visibility: visible;
  transition: 
    opacity var(--t-slow) var(--ease-out),
    visibility var(--t-slow) var(--ease-out);
}

/* Dismiss animation state */
.welcome-overlay.welcome-overlay--hidden {
  opacity: 0;
  visibility: hidden;
}

/* ── Content Layout ─────────────────────────────────────── */
.welcome-overlay__content {
  max-width: var(--content-max);
  width: 100%;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: var(--s-4);
  transform: translateY(0);
  transition: transform var(--t-slow) var(--ease-out);
}

.welcome-overlay.welcome-overlay--hidden .welcome-overlay__content {
  transform: translateY(-20px);
}

/* ── Typography & Elements ─────────────────────────────── */
.welcome-overlay__label {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: var(--tracking-widest);
  text-transform: uppercase;
  color: var(--color-text-3);
  opacity: 0;
  animation: welcomeFadeInUp 0.8s var(--ease-out) forwards;
}

.welcome-overlay__title {
  font-family: var(--font-display);
  font-size: clamp(var(--text-xl), 8vw, var(--text-3xl));
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: var(--tracking-tight);
  color: var(--color-text-1);
  margin: 0;
  opacity: 0;
  animation: welcomeFadeInUp 1s var(--ease-out) 0.15s forwards;
}

.welcome-overlay__subtitle {
  font-family: var(--font-serif);
  font-size: var(--text-base);
  line-height: var(--leading-relaxed);
  color: var(--color-text-2);
  margin: 0;
  max-width: 50ch;
  opacity: 0;
  animation: welcomeFadeInUp 1.2s var(--ease-out) 0.3s forwards;
}

.welcome-overlay__divider {
  width: 48px;
  height: 1px;
  background-color: var(--color-border);
  margin-top: var(--s-2);
  opacity: 0;
  transform: scaleX(0);
  transform-origin: left;
  animation: welcomeDivider 1s var(--ease-out) 0.45s forwards;
}

/* ── Actions Layout (Bottom Right) ─────────────────────── */
.welcome-overlay__actions {
  position: absolute;
  bottom: var(--s-8);
  right: var(--s-8);
  display: flex;
  align-items: center;
  gap: var(--s-4);
  z-index: 100002;
  
  opacity: 0;
  animation: welcomeFadeInUp 1s var(--ease-out) 0.6s forwards;
}

/* ── Buttons ───────────────────────────────────────────── */
.welcome-overlay__btn {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: var(--tracking-wider);
  text-transform: uppercase;
  cursor: pointer;
  
  padding: var(--s-3) var(--s-5);
  border-radius: var(--radius-sm);
  text-decoration: none;
  
  display: flex;
  align-items: center;
  gap: var(--s-3);
  
  transition: 
    background-color var(--t-fast) var(--ease-out),
    color var(--t-fast) var(--ease-out),
    border-color var(--t-fast) var(--ease-out),
    transform var(--t-fast) var(--ease-out),
    box-shadow var(--t-fast) var(--ease-out);
}

.welcome-overlay__btn-arrow {
  display: inline-block;
  transition: transform var(--t-fast) var(--ease-out);
}

/* Primary — Solid high visibility */
.welcome-overlay__btn--primary {
  background: var(--color-text-1);
  color: var(--color-bg);
  border: var(--border-width) solid var(--color-text-1);
}

.welcome-overlay__btn--primary:hover {
  background-color: var(--color-accent-h);
  border-color: var(--color-accent-h);
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
}

html[data-theme="dark"] .welcome-overlay__btn--primary:hover {
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.4);
}

.welcome-overlay__btn--primary:hover .welcome-overlay__btn-arrow {
  transform: translateX(4px);
}

/* Secondary — Outline/Ghost */
.welcome-overlay__btn--secondary {
  background: transparent;
  color: var(--color-text-2);
  border: var(--border-width) solid var(--color-border);
}

.welcome-overlay__btn--secondary:hover {
  color: var(--color-text-1);
  border-color: var(--color-text-1);
  transform: translateY(-2px);
}

.welcome-overlay__btn--secondary:hover .welcome-overlay__btn-arrow {
  transform: translateY(-1px) translateX(1px);
}

.welcome-overlay__btn:active {
  transform: translateY(0);
}

/* ── Keyframes ─────────────────────────────────────────── */
@keyframes welcomeFadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes welcomeDivider {
  from {
    opacity: 0;
    transform: scaleX(0);
  }
  to {
    opacity: 1;
    transform: scaleX(1);
  }
}

/* ── Mobile Layout Adjustments ──────────────────────────── */
@media (max-width: 768px) {
  .welcome-overlay {
    padding: var(--s-6);
    justify-content: flex-end; /* Push content to middle-bottom on mobile */
  }
  
  .welcome-overlay__content {
    margin-bottom: var(--s-8);
  }
  
  .welcome-overlay__actions {
    position: relative;
    bottom: 0;
    right: 0;
    width: 100%;
    flex-direction: column;
    gap: var(--s-3);
  }
  
  .welcome-overlay__btn {
    width: 100%;
    justify-content: center;
    padding: var(--s-4) var(--s-5);
  }
}