/* Liquid Glass & Metal Button Component
   Vanilla CSS for reusable button styles with glass morphism & metal effects
   No external dependencies required
*/

/* ================ Base Button Styles ================ */
.liquid-btn {
  /* Reset native button styles */
  -webkit-appearance: none;
  appearance: none;
  border: none;
  background: transparent;
  cursor: pointer;
  padding: 0;
  margin: 0;
  font-family: inherit;
  font-size: inherit;
  line-height: inherit;
  color: inherit;

  /* Component foundation */
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  overflow: hidden;
  border-radius: 12px;
  font-weight: 600;
  transition: all 0.3s cubic-bezier(0.2, 0.9, 0.3, 1);
  user-select: none;
  -webkit-user-select: none;
  touch-action: manipulation;

  /* Accessibility */
  outline-offset: 2px;
}

/* Focus ring (accessible) */
.liquid-btn:focus-visible {
  outline: 2px solid;
  outline-color: currentColor;
}

/* Disabled state */
.liquid-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  pointer-events: none;
}

/* ================ Liquid Glass Layers ================ */
.liquid-overlay {
  position: absolute;
  inset: 0;
  border-radius: inherit;
  opacity: 0.08;
  background: linear-gradient(
    135deg,
    rgba(255, 255, 255, 0.4),
    rgba(255, 255, 255, 0.1),
    rgba(255, 255, 255, 0)
  );
  pointer-events: none;
  transition: opacity 0.3s ease;
}

.liquid-inner {
  position: absolute;
  inset: 1px;
  border-radius: calc(inherit - 1px);
  background: linear-gradient(
    180deg,
    rgba(255, 255, 255, 0.15),
    rgba(255, 255, 255, 0.05)
  );
  opacity: 0.6;
  pointer-events: none;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  transition: all 0.3s ease;
}

.liquid-content {
  position: relative;
  z-index: 2;
  display: inline-flex;
  align-items: center;
  gap: inherit;
  white-space: nowrap;
}

/* ================ Size Variants ================ */

/* Small */
.liquid-btn[data-size="sm"] {
  padding: 0.5rem 0.875rem;
  font-size: 0.875rem;
  gap: 0.375rem;
}

.liquid-btn[data-size="sm"] .liquid-content {
  gap: 0.375rem;
}

/* Default */
.liquid-btn[data-size="default"],
.liquid-btn:not([data-size]) {
  padding: 0.75rem 1.5rem;
  font-size: 1rem;
  gap: 0.5rem;
}

.liquid-btn[data-size="default"] .liquid-content,
.liquid-btn:not([data-size]) .liquid-content {
  gap: 0.5rem;
}

/* Large */
.liquid-btn[data-size="lg"] {
  padding: 1rem 2rem;
  font-size: 1.125rem;
  gap: 0.625rem;
}

.liquid-btn[data-size="lg"] .liquid-content {
  gap: 0.625rem;
}

/* Icon-only (square button) */
.liquid-btn[data-size="icon"] {
  padding: 0.625rem;
  width: 2.5rem;
  height: 2.5rem;
  font-size: 1rem;
}

/* Extra-large */
.liquid-btn[data-size="xl"] {
  padding: 1.25rem 2.5rem;
  font-size: 1.25rem;
  gap: 0.75rem;
  border-radius: 16px;
}

.liquid-btn[data-size="xl"] .liquid-content {
  gap: 0.75rem;
}

/* ================ Color Variants ================ */

/* Default (Primary Blue) */
.liquid-btn[data-variant="default"],
.liquid-btn:not([data-variant]) {
  background: linear-gradient(
    135deg,
    rgba(59, 130, 246, 0.15),
    rgba(29, 78, 216, 0.1)
  );
  border: 1px solid rgba(59, 130, 246, 0.3);
  color: rgb(59, 130, 246);
  box-shadow: 0 8px 24px rgba(59, 130, 246, 0.15),
    inset 0 1px 0 rgba(255, 255, 255, 0.2);
}

.liquid-btn[data-variant="default"]:hover,
.liquid-btn:not([data-variant]):hover {
  background: linear-gradient(
    135deg,
    rgba(59, 130, 246, 0.25),
    rgba(29, 78, 216, 0.2)
  );
  border-color: rgba(59, 130, 246, 0.5);
  box-shadow: 0 12px 32px rgba(59, 130, 246, 0.25),
    inset 0 1px 0 rgba(255, 255, 255, 0.3);
  transform: translateY(-2px);
}

.liquid-btn[data-variant="default"]:active,
.liquid-btn[data-variant="default"].pressed,
.liquid-btn:not([data-variant]):active,
.liquid-btn:not([data-variant]).pressed {
  transform: translateY(0);
  box-shadow: 0 4px 12px rgba(59, 130, 246, 0.15),
    inset 0 1px 0 rgba(255, 255, 255, 0.1);
}

/* Cool (Cyan) */
.liquid-btn[data-variant="cool"] {
  background: linear-gradient(
    135deg,
    rgba(6, 182, 212, 0.15),
    rgba(0, 147, 195, 0.1)
  );
  border: 1px solid rgba(6, 182, 212, 0.3);
  color: rgb(6, 182, 212);
  box-shadow: 0 8px 24px rgba(6, 182, 212, 0.15),
    inset 0 1px 0 rgba(255, 255, 255, 0.2);
}

.liquid-btn[data-variant="cool"]:hover {
  background: linear-gradient(
    135deg,
    rgba(6, 182, 212, 0.25),
    rgba(0, 147, 195, 0.2)
  );
  border-color: rgba(6, 182, 212, 0.5);
  box-shadow: 0 12px 32px rgba(6, 182, 212, 0.25),
    inset 0 1px 0 rgba(255, 255, 255, 0.3);
  transform: translateY(-2px);
}

.liquid-btn[data-variant="cool"]:active,
.liquid-btn[data-variant="cool"].pressed {
  transform: translateY(0);
  box-shadow: 0 4px 12px rgba(6, 182, 212, 0.15),
    inset 0 1px 0 rgba(255, 255, 255, 0.1);
}

/* Destructive (Red) */
.liquid-btn[data-variant="destructive"] {
  background: linear-gradient(
    135deg,
    rgba(239, 68, 68, 0.15),
    rgba(220, 38, 38, 0.1)
  );
  border: 1px solid rgba(239, 68, 68, 0.3);
  color: rgb(239, 68, 68);
  box-shadow: 0 8px 24px rgba(239, 68, 68, 0.15),
    inset 0 1px 0 rgba(255, 255, 255, 0.2);
}

.liquid-btn[data-variant="destructive"]:hover {
  background: linear-gradient(
    135deg,
    rgba(239, 68, 68, 0.25),
    rgba(220, 38, 38, 0.2)
  );
  border-color: rgba(239, 68, 68, 0.5);
  box-shadow: 0 12px 32px rgba(239, 68, 68, 0.25),
    inset 0 1px 0 rgba(255, 255, 255, 0.3);
  transform: translateY(-2px);
}

.liquid-btn[data-variant="destructive"]:active,
.liquid-btn[data-variant="destructive"].pressed {
  transform: translateY(0);
  box-shadow: 0 4px 12px rgba(239, 68, 68, 0.15),
    inset 0 1px 0 rgba(255, 255, 255, 0.1);
}

/* Secondary (Purple) */
.liquid-btn[data-variant="secondary"] {
  background: linear-gradient(
    135deg,
    rgba(168, 85, 247, 0.15),
    rgba(147, 51, 234, 0.1)
  );
  border: 1px solid rgba(168, 85, 247, 0.3);
  color: rgb(168, 85, 247);
  box-shadow: 0 8px 24px rgba(168, 85, 247, 0.15),
    inset 0 1px 0 rgba(255, 255, 255, 0.2);
}

.liquid-btn[data-variant="secondary"]:hover {
  background: linear-gradient(
    135deg,
    rgba(168, 85, 247, 0.25),
    rgba(147, 51, 234, 0.2)
  );
  border-color: rgba(168, 85, 247, 0.5);
  box-shadow: 0 12px 32px rgba(168, 85, 247, 0.25),
    inset 0 1px 0 rgba(255, 255, 255, 0.3);
  transform: translateY(-2px);
}

.liquid-btn[data-variant="secondary"]:active,
.liquid-btn[data-variant="secondary"].pressed {
  transform: translateY(0);
  box-shadow: 0 4px 12px rgba(168, 85, 247, 0.15),
    inset 0 1px 0 rgba(255, 255, 255, 0.1);
}

/* Ghost (Minimal, no background) */
.liquid-btn[data-variant="ghost"] {
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.2);
  color: rgba(255, 255, 255, 0.7);
  box-shadow: none;
}

.liquid-btn[data-variant="ghost"]:hover {
  background: rgba(255, 255, 255, 0.08);
  border-color: rgba(255, 255, 255, 0.4);
  color: rgba(255, 255, 255, 0.9);
  transform: translateY(-2px);
  box-shadow: 0 8px 16px rgba(255, 255, 255, 0.1);
}

.liquid-btn[data-variant="ghost"]:active,
.liquid-btn[data-variant="ghost"].pressed {
  transform: translateY(0);
  box-shadow: none;
}

/* Outline (Bordered, transparent) */
.liquid-btn[data-variant="outline"] {
  background: transparent;
  border: 2px solid currentColor;
  color: rgb(59, 130, 246);
  box-shadow: none;
}

.liquid-btn[data-variant="outline"]:hover {
  background: rgba(59, 130, 246, 0.1);
  box-shadow: 0 8px 16px rgba(59, 130, 246, 0.1);
  transform: translateY(-2px);
}

.liquid-btn[data-variant="outline"]:active,
.liquid-btn[data-variant="outline"].pressed {
  transform: translateY(0);
  box-shadow: inset 0 2px 4px rgba(0, 0, 0, 0.1);
}

/* Link (Text-only) */
.liquid-btn[data-variant="link"] {
  background: transparent;
  border: none;
  color: rgb(59, 130, 246);
  text-decoration: underline;
  text-underline-offset: 4px;
  box-shadow: none;
  padding: 0.25rem 0.5rem;
  border-radius: 4px;
}

.liquid-btn[data-variant="link"]:hover {
  background: transparent;
  color: rgb(29, 78, 216);
  text-decoration: underline;
}

.liquid-btn[data-variant="link"]:active,
.liquid-btn[data-variant="link"].pressed {
  color: rgb(29, 78, 216);
  opacity: 0.8;
}

/* ================ Interactive States ================ */

/* Hover overlay enhancement */
.liquid-btn:hover .liquid-overlay,
.liquid-btn:hover.pressed .liquid-overlay {
  opacity: 0.12;
}

/* Hover inner glow */
.liquid-btn:hover .liquid-inner,
.liquid-btn:hover.pressed .liquid-inner {
  opacity: 0.8;
  background: linear-gradient(
    180deg,
    rgba(255, 255, 255, 0.25),
    rgba(255, 255, 255, 0.08)
  );
}

/* Active/Pressed state */
.liquid-btn:active .liquid-inner,
.liquid-btn.pressed .liquid-inner {
  opacity: 0.5;
}

/* ================ Metal Button Variant ================ */
.metal-btn {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  font-size: 1rem;
  font-weight: 600;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  overflow: hidden;
  user-select: none;
  -webkit-user-select: none;
  touch-action: manipulation;
  outline-offset: 2px;
  background: linear-gradient(
    180deg,
    #e5e7eb 0%,
    #d1d5db 45%,
    #9ca3af 50%,
    #d1d5db 55%,
    #e5e7eb 100%
  );
  color: #1f2937;
  box-shadow: 0 8px 16px rgba(0, 0, 0, 0.2),
    inset 0 1px 0 rgba(255, 255, 255, 0.5), inset 0 -1px 0 rgba(0, 0, 0, 0.3);
  transition: all 0.2s ease;
  -webkit-appearance: none;
  appearance: none;
}

.metal-btn:focus-visible {
  outline: 2px solid currentColor;
}

.metal-btn:hover {
  background: linear-gradient(
    180deg,
    #f3f4f6 0%,
    #e5e7eb 45%,
    #a3a8af 50%,
    #e5e7eb 55%,
    #f3f4f6 100%
  );
  box-shadow: 0 12px 24px rgba(0, 0, 0, 0.25),
    inset 0 1px 0 rgba(255, 255, 255, 0.6), inset 0 -1px 0 rgba(0, 0, 0, 0.4);
  transform: translateY(-2px);
}

.metal-btn:active,
.metal-btn.pressed {
  background: linear-gradient(
    180deg,
    #d1d5db 0%,
    #9ca3af 45%,
    #6b7280 50%,
    #9ca3af 55%,
    #d1d5db 100%
  );
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.25),
    inset 0 -1px 0 rgba(255, 255, 255, 0.2), inset 0 1px 0 rgba(0, 0, 0, 0.3);
  transform: translateY(0);
}

.metal-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  pointer-events: none;
}

/* Metal button sizes */
.metal-btn[data-size="sm"] {
  padding: 0.5rem 0.875rem;
  font-size: 0.875rem;
}

.metal-btn[data-size="lg"] {
  padding: 1rem 2rem;
  font-size: 1.125rem;
}

.metal-btn[data-size="icon"] {
  padding: 0.625rem;
  width: 2.5rem;
  height: 2.5rem;
  border-radius: 50%;
}

/* ================ Ripple Effect (optional, applied via JS) ================ */
.ripple {
  position: absolute;
  border-radius: 50%;
  background: radial-gradient(
    circle,
    rgba(255, 255, 255, 0.6),
    rgba(255, 255, 255, 0)
  );
  transform: scale(0);
  pointer-events: none;
  animation: ripple-anim 0.6s ease-out;
}

@keyframes ripple-anim {
  to {
    transform: scale(4);
    opacity: 0;
  }
}

/* ================ Responsive ================ */
@media (max-width: 640px) {
  .liquid-btn[data-size="xl"] {
    padding: 1rem 2rem;
    font-size: 1.125rem;
  }

  .liquid-btn[data-size="lg"] {
    padding: 0.875rem 1.75rem;
    font-size: 1rem;
  }
}

/* Respect reduced motion */
@media (prefers-reduced-motion: reduce) {
  .liquid-btn,
  .metal-btn {
    transition: none;
  }

  .liquid-btn:hover,
  .metal-btn:hover {
    transform: none;
  }

  .ripple {
    animation: none;
  }
}