/* ==========================================================================
   Components: buttons, cards, badges, theme toggle, motion utilities
   ========================================================================== */

/* ---- Buttons ------------------------------------------------------------- */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-5);
  border-radius: var(--radius-full);
  font-size: var(--text-sm);
  font-weight: var(--weight-semibold);
  letter-spacing: var(--tracking-normal);
  line-height: var(--leading-none);
  white-space: nowrap;
  cursor: pointer;
  transition: background-color var(--duration-fast) var(--ease-out),
    color var(--duration-fast) var(--ease-out),
    border-color var(--duration-fast) var(--ease-out),
    transform var(--duration-fast) var(--ease-out),
    box-shadow var(--duration-fast) var(--ease-out);
}

.btn:active {
  transform: translateY(1px);
}

.btn--primary {
  background-color: var(--color-accent);
  color: #fff;
  box-shadow: var(--shadow-sm);
}

.btn--primary:hover {
  background-color: var(--color-accent-hover);
  color: #fff;
  box-shadow: var(--shadow-md);
}

.btn--secondary {
  background-color: var(--color-surface);
  color: var(--color-text);
  border: 1px solid var(--color-border-strong);
}

.btn--secondary:hover {
  color: var(--color-text);
  background-color: var(--color-bg-muted);
  border-color: var(--color-border-strong);
}

/* For placement on a saturated background, where the accent button would
   disappear. Stays white in both themes because the band it sits on does. */
.btn--inverse {
  background-color: #fff;
  color: var(--indigo-700);
  box-shadow: var(--shadow-sm);
}

.btn--inverse:hover {
  background-color: #fff;
  color: var(--indigo-700);
  box-shadow: var(--shadow-lg);
  transform: translateY(-1px);
}

.btn--inverse:active {
  transform: translateY(0);
}

.btn--ghost {
  color: var(--color-text-secondary);
  padding-inline: var(--space-4);
}

.btn--ghost:hover {
  color: var(--color-text);
  background-color: var(--color-bg-muted);
}

.btn--lg {
  padding: var(--space-4) var(--space-8);
  font-size: var(--text-base);
}

/* Arrow nudges right on hover — the one flourish on links and buttons. */
.btn__arrow,
.link-arrow__icon {
  transition: transform var(--duration-base) var(--ease-out);
}

.btn:hover .btn__arrow,
.link-arrow:hover .link-arrow__icon {
  transform: translateX(3px);
}

.link-arrow {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-sm);
  font-weight: var(--weight-semibold);
  color: var(--color-accent-text);
}

/* ---- Badge --------------------------------------------------------------- */

.badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-full);
  background-color: var(--color-accent-soft);
  color: var(--color-accent-text);
  font-size: var(--text-xs);
  font-weight: var(--weight-semibold);
  letter-spacing: var(--tracking-wide);
  text-transform: uppercase;
}

/* Neutral variant, for labels that aren't calls to attention. */
.badge--neutral {
  background-color: var(--color-bg-muted);
  color: var(--color-text-secondary);
  border: 1px solid var(--color-border);
}

/* ---- Card ---------------------------------------------------------------- */

.card {
  padding: var(--space-6);
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  transition: transform var(--duration-base) var(--ease-out),
    box-shadow var(--duration-base) var(--ease-out),
    border-color var(--duration-base) var(--ease-out);
}

.card--interactive:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
  border-color: var(--color-border-strong);
}

.card__title {
  font-size: var(--text-lg);
  font-weight: var(--weight-semibold);
  margin-bottom: var(--space-2);
}

.card__body {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  line-height: var(--leading-relaxed);
}

/* ---- Theme toggle -------------------------------------------------------- */

.theme-toggle {
  display: inline-grid;
  place-items: center;
  width: 2.5rem;
  height: 2.5rem;
  border-radius: var(--radius-full);
  color: var(--color-text-secondary);
  transition: color var(--duration-fast) var(--ease-out),
    background-color var(--duration-fast) var(--ease-out);
}

.theme-toggle:hover {
  color: var(--color-text);
  background-color: var(--color-bg-muted);
}

.theme-toggle__icon {
  width: 1.125rem;
  height: 1.125rem;
  transition: transform var(--duration-base) var(--ease-out),
    opacity var(--duration-fast) var(--ease-out);
}

/* Only one icon shows at a time; the other collapses out of flow. */
.theme-toggle__icon--moon {
  display: none;
}

[data-theme="dark"] .theme-toggle__icon--sun {
  display: none;
}

[data-theme="dark"] .theme-toggle__icon--moon {
  display: block;
}

.theme-toggle:hover .theme-toggle__icon {
  transform: rotate(15deg);
}

/* ---- Prose --------------------------------------------------------------- */

.prose > * + * {
  margin-top: var(--space-5);
}

.prose p {
  color: var(--color-text-secondary);
  line-height: var(--leading-relaxed);
}

.prose h2,
.prose h3 {
  margin-top: var(--space-10);
  color: var(--color-text);
}

/* ---- Scroll reveal ------------------------------------------------------- */

/* Elements start offset and transparent; JS adds .is-visible on intersection.
   The no-js / reduced-motion fallbacks below make sure content is never
   stranded invisible. */
.reveal {
  opacity: 0;
  transform: translateY(var(--reveal-offset));
  transition: opacity var(--duration-slow) var(--ease-out),
    transform var(--duration-slow) var(--ease-out);
  transition-delay: var(--reveal-delay, 0ms);
  will-change: opacity, transform;
}

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

html.no-js .reveal {
  opacity: 1;
  transform: none;
}

@media (prefers-reduced-motion: reduce) {
  .reveal {
    opacity: 1;
    transform: none;
  }
}