/* ============================================================
   COMPONENTS
   Reusable UI primitives that appear across multiple sections:
   .btn, .glass, .tag, .skills__bar, .project-card__expand-icon.
   Each component is self-contained and doesn't depend on context.
   ============================================================ */

/* ── Glass card ─────────────────────────────────────────────
   The core glassmorphism card. Used across:
   timeline__content, skills__category, about__stat-card,
   dsa__stats-card, dsa__topics-card, internship__program,
   project-card, project-mini, achievement.
   backdrop-filter creates the frosted glass depth effect. */
.glass {
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  box-shadow: var(--glass-shadow);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  transition:
    background var(--duration-base) var(--ease-out-quart),
    border-color var(--duration-base) var(--ease-out-quart),
    box-shadow var(--duration-slow) var(--ease-out-quart);
}

.glass:hover {
  background: var(--color-bg-glass-hover);
  border-color: var(--color-border-hover);
  box-shadow: var(--shadow-lg),
              inset 0 1px 0 rgba(255, 255, 255, 0.06);
}

/* ── Buttons ─────────────────────────────────────────────────
   Two variants: primary (filled gradient) and ghost (outlined).
   Both share the same padding and transition setup.
   Two sizes: default and --sm. */

/* Base — shared between both variants */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  border-radius: var(--radius-full);
  font-size: var(--text-sm);
  font-weight: var(--weight-medium);
  letter-spacing: 0.01em;
  white-space: nowrap;
  cursor: pointer;
  position: relative;
  overflow: hidden;
  transition:
    transform var(--duration-base) var(--ease-out-quart),
    box-shadow var(--duration-base) var(--ease-out-quart),
    background var(--duration-base) var(--ease-out-quart),
    color var(--duration-base) var(--ease-out-quart),
    border-color var(--duration-base) var(--ease-out-quart);
  -webkit-user-select: none;
  user-select: none;
}

.btn:active {
  transform: scale(0.97);
}

/* Shimmer layer — appears on hover via ::before */
.btn::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(
    105deg,
    transparent 30%,
    rgba(255, 255, 255, 0.08) 50%,
    transparent 70%
  );
  transform: translateX(-100%);
  transition: transform var(--duration-slow) var(--ease-out-quart);
}

.btn:hover::before {
  transform: translateX(100%);
}

/* Primary — filled with gradient, glows on hover */
.btn--primary {
  background: var(--gradient-accent);
  color: white;
  box-shadow: 0 2px 12px var(--color-accent-glow);
}

.btn--primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 24px var(--color-accent-glow),
              0 2px 8px rgba(99, 102, 241, 0.4);
}

/* Ghost — outlined, fills on hover */
.btn--ghost {
  background: rgba(255, 255, 255, 0.04);
  color: var(--color-text-primary);
  border: 1px solid var(--color-border);
}

.btn--ghost:hover {
  background: rgba(255, 255, 255, 0.08);
  border-color: var(--color-border-hover);
  transform: translateY(-2px);
}

/* Small size modifier */
.btn--sm {
  padding: var(--space-2) var(--space-4);
  font-size: var(--text-xs);
}

/* ── Tags ────────────────────────────────────────────────────
   Technology/skill chips: .tag and .tag--sm.
   Used in: project-card__tech, project-mini__tech,
   skills__marquee (they're spans, not tag elements),
   dsa__platforms, internship__regions. */
.tag {
  display: inline-flex;
  align-items: center;
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-family: var(--font-mono);
  font-weight: var(--weight-medium);
  letter-spacing: 0.02em;
  background: rgba(255, 255, 255, 0.05);
  color: var(--color-text-secondary);
  border: 1px solid var(--color-border);
  white-space: nowrap;
  transition:
    background var(--duration-base) var(--ease-out-quart),
    color var(--duration-base) var(--ease-out-quart),
    border-color var(--duration-base) var(--ease-out-quart);
}

.tag:hover {
  background: var(--color-accent-dim);
  color: var(--color-accent-light);
  border-color: rgba(99, 102, 241, 0.3);
}

.tag--sm {
  font-size: 0.65rem;
  padding: 2px var(--space-2);
}

/* ── Skill bar ───────────────────────────────────────────────
   Progress bar for each skill. Track + animated fill.
   Fill width is set via data-width and animated by JS
   (Intersection Observer adds .is-visible class). */
.skills__bar {
  width: 100%;
  height: 3px;
  background: var(--color-bg-subtle);
  border-radius: var(--radius-full);
  overflow: hidden;
}

.skills__bar-fill {
  height: 100%;
  width: 0%;   /* starts at 0 — JS animates to data-width value */
  border-radius: var(--radius-full);
  background: var(--gradient-accent);
  transition: width 1s var(--ease-out-expo);
  position: relative;
}

/* Animated shimmer on the bar fill */
.skills__bar-fill::after {
  content: '';
  position: absolute;
  top: 0;
  right: 0;
  width: 24px;
  height: 100%;
  background: rgba(255,255,255,0.5);
  border-radius: var(--radius-full);
  filter: blur(4px);
}

/* ── Project expand icon ─────────────────────────────────────
   Chevron rotates when panel is open. */
.project-card__expand-icon {
  transition: transform var(--duration-base) var(--ease-out-quart);
  flex-shrink: 0;
}

.project-card__expand[aria-expanded="true"] .project-card__expand-icon {
  transform: rotate(180deg);
}

/* ── Timeline future badge ───────────────────────────────── */
.timeline__future-badge {
  display: inline-flex;
  align-items: center;
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-full);
  background: var(--color-accent-dim);
  border: 1px solid rgba(99, 102, 241, 0.25);
}

/* ── Hero badge ──────────────────────────────────────────── */
.hero__badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-full);
  background: rgba(34, 197, 94, 0.08);
  border: 1px solid rgba(34, 197, 94, 0.18);
  font-size: var(--text-xs);
  font-weight: var(--weight-medium);
  color: var(--color-success);
  font-family: var(--font-mono);
  letter-spacing: var(--tracking-wide);
  margin-bottom: var(--space-6);
}

/* Pulsing green dot */
.hero__badge-dot {
  width: 7px;
  height: 7px;
  border-radius: var(--radius-full);
  background: var(--color-success);
  animation: pulse-green 2.5s ease-in-out infinite;
  flex-shrink: 0;
}

@keyframes pulse-green {
  0%, 100% {
    box-shadow: 0 0 0 0 rgba(34, 197, 94, 0.4);
    opacity: 1;
  }
  50% {
    box-shadow: 0 0 0 6px rgba(34, 197, 94, 0);
    opacity: 0.8;
  }
}

/* ── Currently strip ─────────────────────────────────────── */
.hero__currently {
  display: flex;
  align-items: flex-start;
  gap: var(--space-4);
  padding: var(--space-4) var(--space-5);
  border-radius: var(--radius-lg);
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  margin-bottom: var(--space-8);
  flex-wrap: wrap;
}

.hero__currently-items {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

/* ── Social icon buttons ─────────────────────────────────── */
.hero__socials {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  margin-top: var(--space-8);
}

.hero__social {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-full);
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--color-border);
  color: var(--color-text-muted);
  transition:
    color var(--duration-base) var(--ease-out-quart),
    background var(--duration-base) var(--ease-out-quart),
    border-color var(--duration-base) var(--ease-out-quart),
    transform var(--duration-base) var(--ease-spring);
}

.hero__social:hover {
  color: var(--color-text-primary);
  background: rgba(255, 255, 255, 0.08);
  border-color: var(--color-border-hover);
  transform: translateY(-3px);
}

/* ── Scroll indicator ────────────────────────────────────── */
.hero__scroll {
  position: absolute;
  bottom: var(--space-10);
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-2);
  color: var(--color-text-muted);
  font-size: var(--text-xs);
  font-family: var(--font-mono);
  letter-spacing: var(--tracking-wider);
  text-transform: uppercase;
  animation: float-up-down 3s ease-in-out infinite;
}

.hero__scroll-line {
  width: 1px;
  height: 48px;
  background: linear-gradient(
    to bottom,
    var(--color-accent),
    transparent
  );
  animation: scroll-line 2s ease-in-out infinite;
}

@keyframes scroll-line {
  0%   { transform: scaleY(0); transform-origin: top; opacity: 0; }
  30%  { opacity: 1; }
  100% { transform: scaleY(1); transform-origin: top; opacity: 0; }
}

@keyframes float-up-down {
  0%, 100% { transform: translateX(-50%) translateY(0); }
  50%       { transform: translateX(-50%) translateY(6px); }
}

/* ── Floating chips on portrait ──────────────────────────── */
.hero__chip {
  position: absolute;
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-full);
  background: rgba(8, 8, 8, 0.85);
  backdrop-filter: blur(12px);
  border: 1px solid var(--color-border);
  font-size: var(--text-xs);
  font-family: var(--font-mono);
  font-weight: var(--weight-medium);
  color: var(--color-text-primary);
  white-space: nowrap;
  box-shadow: var(--shadow-md);
  pointer-events: none;
}

.hero__chip--1 {
  top: 15%;
  right: -20px;
  animation: chip-float 4s ease-in-out infinite;
}

.hero__chip--2 {
  top: 50%;
  left: -28px;
  animation: chip-float 5s ease-in-out infinite 0.8s;
}

.hero__chip--3 {
  bottom: 20%;
  right: -16px;
  animation: chip-float 4.5s ease-in-out infinite 1.5s;
}

@keyframes chip-float {
  0%, 100% { transform: translateY(0px); }
  50%       { transform: translateY(-8px); }
}