/* ============================================================
   ANIMATIONS
   All @keyframes and the reveal system.
   Reveal classes start in their "hidden" state and transition
   to visible when JS adds .is-visible via IntersectionObserver.
   Duration and easing from variables.css tokens.
   ============================================================ */

/* ── Reveal: fade up ────────────────────────────────────────
   Used on: section headers, about paragraphs, skill categories,
   achievement cards, internship items.
   Starts 24px below, opacity 0. */
.reveal-up {
  opacity: 0;
  transform: translateY(24px);
  transition:
    opacity var(--duration-reveal) var(--ease-out-expo),
    transform var(--duration-reveal) var(--ease-out-expo);
}

.reveal-up.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* ── Reveal: fade only ───────────────────────────────────────
   Used on: hero badge, currently strip, hero actions,
   hero socials, skills marquee.
   No translate — pure opacity fade. */
.reveal-fade {
  opacity: 0;
  transition: opacity var(--duration-reveal) var(--ease-out-expo);
}

.reveal-fade.is-visible {
  opacity: 1;
}

/* ── Reveal: scale up ────────────────────────────────────────
   Used on: hero portrait.
   Starts slightly smaller, scales to full size. */
.reveal-scale {
  opacity: 0;
  transform: scale(0.92);
  transition:
    opacity var(--duration-reveal) var(--ease-out-expo),
    transform var(--duration-reveal) var(--ease-spring);
}

.reveal-scale.is-visible {
  opacity: 1;
  transform: scale(1);
}

/* ── Reveal: timeline items ──────────────────────────────────
   Slides in from the left — feels like the timeline is
   being drawn as you scroll. */
.reveal-timeline {
  opacity: 0;
  transform: translateX(-16px);
  transition:
    opacity var(--duration-reveal) var(--ease-out-expo),
    transform var(--duration-reveal) var(--ease-out-expo);
}

.reveal-timeline.is-visible {
  opacity: 1;
  transform: translateX(0);
}

/* ── Staggered delays ────────────────────────────────────────
   JS reads data-delay and applies it as a transition-delay
   inline via style.transitionDelay.
   These classes are fallbacks if JS hasn't set them yet. */
[data-delay="0"]   { transition-delay: 0ms; }
[data-delay="80"]  { transition-delay: 80ms; }
[data-delay="100"] { transition-delay: 100ms; }
[data-delay="120"] { transition-delay: 120ms; }
[data-delay="160"] { transition-delay: 160ms; }
[data-delay="200"] { transition-delay: 200ms; }
[data-delay="240"] { transition-delay: 240ms; }
[data-delay="300"] { transition-delay: 300ms; }
[data-delay="320"] { transition-delay: 320ms; }
[data-delay="400"] { transition-delay: 400ms; }
[data-delay="500"] { transition-delay: 500ms; }
[data-delay="600"] { transition-delay: 600ms; }

/* ── Reduced motion override ─────────────────────────────────
   When the OS reduces motion, snap elements to visible
   immediately — no transitions, no transforms. */
@media (prefers-reduced-motion: reduce) {
  .reveal-up,
  .reveal-fade,
  .reveal-scale,
  .reveal-timeline {
    opacity: 1;
    transform: none;
    transition: none;
  }
}

/* ── Keyframes ───────────────────────────────────────────────
   All @keyframes defined here; referenced across other files. */

/* Marquee: horizontal infinite scroll */
@keyframes marquee {
  from { transform: translateX(0); }
  to   { transform: translateX(-50%); }
}

/* Case study panel: slides down when revealed */
@keyframes slide-down {
  from {
    opacity: 0;
    transform: translateY(-8px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Generic fade in (used by JS-triggered elements) */
@keyframes fade-in {
  from { opacity: 0; }
  to   { opacity: 1; }
}

/* Shimmer sweep — used on skill bar fills */
@keyframes shimmer {
  0%   { background-position: -200% center; }
  100% { background-position: 200% center; }
}

/* Soft scale pulse — used on portrait glow */
@keyframes pulse {
  0%, 100% { transform: scale(1); opacity: 0.6; }
  50%       { transform: scale(1.08); opacity: 0.9; }
}

/* Spin — used for loader states if needed */
@keyframes spin {
  from { transform: rotate(0deg); }
  to   { transform: rotate(360deg); }
}

/* Bounce in — used for chip entrance */
@keyframes bounce-in {
  0%   { opacity: 0; transform: scale(0.7) translateY(8px); }
  60%  { transform: scale(1.05) translateY(-4px); }
  80%  { transform: scale(0.98) translateY(2px); }
  100% { opacity: 1; transform: scale(1) translateY(0); }
}

/* Counter number change — subtle scale on update */
@keyframes count-tick {
  0%   { transform: translateY(0); }
  30%  { transform: translateY(-4px); opacity: 0.6; }
  100% { transform: translateY(0); opacity: 1; }
}

/* ── Nav transition animations ───────────────────────────────
   Handled via class toggling in layout.css,
   but these are the underlying keyframes. */

/* Hero chip entrance — staggered on page load */
.hero__chip--1 { animation-delay: 0.8s; }
.hero__chip--2 { animation-delay: 1.1s; }
.hero__chip--3 { animation-delay: 1.4s; }

/* Orb entrance */
.hero__orb--1 {
  animation: orb-drift 14s ease-in-out infinite alternate;
}
.hero__orb--2 {
  animation: orb-drift 18s ease-in-out infinite alternate-reverse;
}

/* ── Page load entrance ──────────────────────────────────────
   The body fades in on initial load.
   JS removes the loading class once DOM is ready. */
body.is-loading {
  overflow: hidden;
}

body.is-loading * {
  animation-play-state: paused !important;
}

/* ── Hover: interactive lift ─────────────────────────────────
   Generic hover lift utility. Applied to cards that don't
   have their own hover transform already. */
.hover-lift {
  transition: transform var(--duration-slow) var(--ease-out-quart);
}

.hover-lift:hover {
  transform: translateY(-4px);
}

/* ── Accent underline animation ──────────────────────────────
   For inline links that slide an underline in on hover.
   Used in the nav and elsewhere. */
.link-underline {
  position: relative;
}

.link-underline::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0%;
  height: 1px;
  background: currentColor;
  transition: width var(--duration-slow) var(--ease-out-expo);
}

.link-underline:hover::after {
  width: 100%;
}