/* Button Components - Apple-inspired */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  position: relative;
  padding: var(--space-4) var(--space-5);
  border-radius: 12px;
  font-family: var(--font-family);
  font-weight: 600;
  font-size: var(--fs-callout);
  line-height: var(--line-height-tight);
  letter-spacing: 0.01em;
  cursor: pointer;
  transition: all var(--ms-duration-fast) var(--curve-spring);
  border: none;
  outline: none;
  text-decoration: none;
  gap: var(--space-2);
  white-space: nowrap;
  user-select: none;
  -webkit-user-select: none;
}

/* Button variants */
.btn-primary {
  background: var(--apple-blue);
  color: #FFFFFF;
  box-shadow: var(--shadow-sm);
}

.btn-primary:hover {
  background: #005BD3;
  transform: translateY(-1px);
  box-shadow: var(--shadow-base);
}

.btn-primary:active {
  background: #0046A3;
  transform: translateY(0);
  box-shadow: var(--shadow-sm);
}

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

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

.btn-secondary:active {
  background: var(--bg-quaternary);
}

.btn-ghost {
  background: transparent;
  color: var(--text-primary);
  border: none;
}

.btn-ghost:hover {
  background: var(--bg-secondary);
}

.btn-ghost:active {
  background: var(--bg-tertiary);
}

/* Button sizes */
.btn-sm {
  padding: var(--space-3) var(--space-4);
  font-size: var(--fs-caption-1);
}

.btn-lg {
  padding: var(--space-5) var(--space-7);
  font-size: var(--fs-body);
}

/* Icon buttons */
.btn-icon {
  width: 44px;
  height: 44px;
  padding: 0;
  border-radius: 50%;
  background: transparent;
  color: var(--text-secondary);
  font-size: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.btn-icon:hover {
  background: var(--bg-secondary);
  color: var(--text-primary);
}

.btn-icon:active {
  background: var(--bg-tertiary);
}

/* Focus states */
.btn:focus-visible {
  outline: none;
  box-shadow: var(--focus-ring);
}

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

/* Loading state */
.btn-loading {
  position: relative;
  color: transparent;
}

.btn-loading::after {
  content: '';
  position: absolute;
  width: 16px;
  height: 16px;
  top: 50%;
  left: 50%;
  margin-left: -8px;
  margin-top: -8px;
  border: 2px solid transparent;
  border-top: 2px solid currentColor;
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

/* Dark theme adjustments */
[data-theme='dark'] .btn-primary {
  background: var(--apple-blue);
}

[data-theme='dark'] .btn-primary:hover {
  background: #4DA3FF;
}

[data-theme='dark'] .btn-primary:active {
  background: #3385FF;
}

[data-theme='dark'] .btn-secondary {
  background: var(--bg-tertiary);
  border-color: var(--border-color);
  color: var(--text-primary);
}

[data-theme='dark'] .btn-secondary:hover {
  background: var(--bg-quaternary);
}

[data-theme='dark'] .btn-icon:hover {
  background: var(--bg-tertiary);
}

[data-theme='dark'] .btn-icon:active {
  background: var(--bg-quaternary);
}

@keyframes spin {
  to { transform: rotate(360deg); }
}