/* ==========================================================================
   button.css — Button component & variants
   Levii Portal · Layout Base / Phase 2
   ========================================================================== */

.btn {
  --btn-bg: var(--surface-2);
  --btn-fg: var(--text);
  --btn-border: var(--border);
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2xs);
  padding: 0.8rem 1.4rem;
  font-family: var(--font-sans);
  font-size: var(--text-base);
  font-weight: 600;
  line-height: 1;
  letter-spacing: -0.01em;
  color: var(--btn-fg);
  background: var(--btn-bg);
  border: 1px solid var(--btn-border);
  border-radius: var(--radius-pill);
  /* Clip the primary button's sheen sweep (::before) to the pill so it never
     bleeds onto neighbours at rest, nor past the rounded edges on hover.
     box-shadow (the glow) sits outside the border-box and is NOT clipped. */
  overflow: hidden;
  /* Own stacking context so the sheen (::before, z-index:-1) sits above the
     gradient background but BELOW the label — the shine passes without washing
     out the text. */
  isolation: isolate;
  cursor: pointer;
  white-space: nowrap;
  transition: transform var(--dur-fast) var(--ease-out),
    box-shadow var(--dur-base) var(--ease-out), background var(--dur-base) var(--ease-out),
    filter var(--dur-base) var(--ease-out);
  -webkit-tap-highlight-color: transparent;
}

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

/* Buttons are often <a> elements — keep their own label color on hover/focus so
   the global `a:hover { color: purple }` rule can't turn the text illegible.
   Variant hover rules (e.g. .btn--secondary) still override this by cascade. */
.btn:hover,
.btn:focus,
.btn:focus-visible {
  color: var(--btn-fg);
}

.btn__icon {
  width: 1.15em;
  height: 1.15em;
  flex: none;
}

/* ---- Primary (gradient, glowing) ------------------------------------- */
.btn--primary {
  --btn-fg: #fff;
  --btn-border: transparent;
  background: var(--gradient-brand);
  background-size: 160% 160%;
  box-shadow: 0 8px 24px -6px rgba(58, 134, 255, 0.55);
}
@media (hover: hover) {
  .btn--primary:hover {
    box-shadow: 0 12px 34px -6px rgba(58, 134, 255, 0.7), var(--shadow-glow);
    background-position: 100% 50%;
    transform: translateY(-2px);
  }
}

/* Sheen sweep on primary hover. */
.btn--primary::before {
  content: '';
  position: absolute;
  inset: 0;
  z-index: -1; /* behind the label, above the gradient (see .btn isolation) */
  /* Thin, low-opacity glint: a narrow bright band that never lightens the
     backdrop enough to hurt the white label's contrast as it sweeps past. */
  background: linear-gradient(
    115deg,
    transparent 42%,
    rgba(255, 255, 255, 0.22) 50%,
    transparent 58%
  );
  transform: translateX(-120%);
  transition: transform var(--dur-slow) var(--ease-out);
  pointer-events: none;
}
@media (hover: hover) {
  .btn--primary:hover::before {
    transform: translateX(120%);
  }
}

/* ---- Secondary (glass outline) --------------------------------------- */
.btn--secondary {
  --btn-fg: var(--text);
  background: var(--glass-bg);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
  --btn-border: var(--border-strong);
}
@media (hover: hover) {
  .btn--secondary:hover {
    border-color: var(--brand-blue-500);
    color: var(--brand-blue-500);
    transform: translateY(-2px);
  }
}

/* ---- Ghost ------------------------------------------------------------ */
.btn--ghost {
  --btn-bg: transparent;
  --btn-border: transparent;
}
@media (hover: hover) {
  .btn--ghost:hover {
    --btn-bg: var(--surface-2);
  }
}

/* ---- Sizes ------------------------------------------------------------ */
.btn--lg {
  padding: 1rem 1.9rem;
  font-size: var(--text-lg);
}
.btn--sm {
  padding: 0.55rem 1rem;
  font-size: var(--text-sm);
}
.btn--block {
  width: 100%;
}

/* ---- Store badge button (App Store / Google Play) -------------------- */
.btn-store {
  display: inline-flex;
  align-items: center;
  gap: 0.7rem;
  padding: 0.7rem 1.25rem;
  border-radius: var(--radius-md);
  background: var(--text);
  color: var(--bg);
  border: 1px solid transparent;
  transition: transform var(--dur-fast) var(--ease-out), box-shadow var(--dur-base) var(--ease-out);
}
.btn-store:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-lg);
  color: var(--bg);
}
.btn-store svg {
  width: 26px;
  height: 26px;
  flex: none;
}
.btn-store__meta {
  display: flex;
  flex-direction: column;
  line-height: 1.15;
  text-align: left;
}
.btn-store__meta small {
  font-size: 0.62rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  opacity: 0.8;
}
.btn-store__meta strong {
  font-size: var(--text-base);
  font-weight: 700;
}

/* Disabled state. */
.btn:disabled,
.btn[aria-disabled='true'] {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none;
}