/**
 * Modern Button System
 * ClickUp-Inspired Interactive Buttons
 * Version 2.0 - December 2025
 */

/* ========================================
   BUTTON BASE STYLES
   ======================================== */

.btn-modern {
  /* Layout */
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  
  /* Sizing */
  padding: var(--space-3) var(--space-5);
  
  /* Typography */
  font-family: var(--font-sans);
  font-size: var(--text-base);
  font-weight: var(--font-medium);
  line-height: 1;
  white-space: nowrap;
  text-decoration: none;
  
  /* Appearance */
  border-radius: var(--radius-md);
  border: none;
  cursor: pointer;
  
  /* Transitions */
  transition: all var(--transition-base);
  
  /* States */
  user-select: none;
}

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

/* ========================================
   BUTTON VARIANTS
   ======================================== */

/* Primary Button */
.btn-primary {
  background: var(--color-primary);
  color: white;
  box-shadow: var(--shadow-sm);
}

.btn-primary:hover {
  background: var(--color-primary-hover);
  box-shadow: var(--shadow-md);
  transform: translateY(-1px);
}

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

/* Secondary Button */
.btn-secondary {
  background: white;
  color: var(--color-gray-700);
  border: 1px solid var(--color-gray-300);
  box-shadow: var(--shadow-xs);
}

.btn-secondary:hover {
  background: var(--color-gray-50);
  border-color: var(--color-gray-400);
  box-shadow: var(--shadow-sm);
}

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

.dark .btn-secondary:hover {
  background: var(--dark-bg-tertiary);
  border-color: var(--color-gray-600);
}

/* Ghost Button (Transparent) */
.btn-ghost {
  background: transparent;
  color: var(--color-gray-700);
  border: none;
}

.btn-ghost:hover {
  background: var(--color-gray-100);
  color: var(--color-primary);
}

.dark .btn-ghost {
  color: var(--dark-text-secondary);
}

.dark .btn-ghost:hover {
  background: var(--dark-bg-tertiary);
  color: var(--color-primary-light);
}

/* Outline Button */
.btn-outline {
  background: transparent;
  color: var(--color-primary);
  border: 2px solid var(--color-primary);
}

.btn-outline:hover {
  background: var(--color-primary);
  color: white;
}

/* Success Button */
.btn-success {
  background: var(--color-success);
  color: white;
  box-shadow: var(--shadow-sm);
}

.btn-success:hover {
  background: var(--color-success-dark);
  box-shadow: var(--shadow-md);
  transform: translateY(-1px);
}

/* Warning Button */
.btn-warning {
  background: var(--color-warning);
  color: white;
  box-shadow: var(--shadow-sm);
}

.btn-warning:hover {
  background: var(--color-warning-dark);
  box-shadow: var(--shadow-md);
  transform: translateY(-1px);
}

/* Danger Button */
.btn-danger {
  background: var(--color-danger);
  color: white;
  box-shadow: var(--shadow-sm);
}

.btn-danger:hover {
  background: var(--color-danger-dark);
  box-shadow: var(--shadow-md);
  transform: translateY(-1px);
}

/* Info Button */
.btn-info {
  background: var(--color-info);
  color: white;
  box-shadow: var(--shadow-sm);
}

.btn-info:hover {
  background: var(--color-info-dark);
  box-shadow: var(--shadow-md);
  transform: translateY(-1px);
}

/* ========================================
   BUTTON SIZES
   ======================================== */

/* Extra Small */
.btn-xs {
  padding: var(--space-1) var(--space-2);
  font-size: var(--text-xs);
  gap: var(--space-1);
}

/* Small */
.btn-sm {
  padding: var(--space-2) var(--space-3);
  font-size: var(--text-sm);
}

/* Medium (Default - already defined in btn-modern) */

/* Large */
.btn-lg {
  padding: var(--space-4) var(--space-6);
  font-size: var(--text-lg);
  gap: var(--space-3);
}

/* Extra Large */
.btn-xl {
  padding: var(--space-5) var(--space-8);
  font-size: var(--text-xl);
  gap: var(--space-3);
}

/* ========================================
   ICON BUTTONS
   ======================================== */

.btn-icon {
  width: 40px;
  height: 40px;
  padding: 0;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
}

.btn-icon.btn-sm {
  width: 32px;
  height: 32px;
}

.btn-icon.btn-lg {
  width: 48px;
  height: 48px;
}

.btn-icon.btn-xl {
  width: 56px;
  height: 56px;
}

/* Rounded Icon Buttons */
.btn-icon-rounded {
  border-radius: var(--radius-full);
}

/* ========================================
   BUTTON STATES
   ======================================== */

/* Loading State */
.btn-loading {
  position: relative;
  opacity: 0.7;
  cursor: wait;
  pointer-events: none;
}

.btn-loading::before {
  content: '';
  position: absolute;
  width: 16px;
  height: 16px;
  border: 2px solid currentColor;
  border-top-color: transparent;
  border-radius: 50%;
  animation: spin 0.6s linear infinite;
}

/* Loading with Text */
.btn-loading-text {
  opacity: 0;
}

/* ========================================
   BUTTON GROUPS
   ======================================== */

.btn-group {
  display: inline-flex;
  gap: 0;
}

.btn-group .btn-modern {
  border-radius: 0;
  margin-left: -1px;
}

.btn-group .btn-modern:first-child {
  border-top-left-radius: var(--radius-md);
  border-bottom-left-radius: var(--radius-md);
  margin-left: 0;
}

.btn-group .btn-modern:last-child {
  border-top-right-radius: var(--radius-md);
  border-bottom-right-radius: var(--radius-md);
}

.btn-group .btn-modern:hover {
  z-index: 1;
}

/* Vertical Button Group */
.btn-group-vertical {
  display: inline-flex;
  flex-direction: column;
  gap: 0;
}

.btn-group-vertical .btn-modern {
  border-radius: 0;
  margin-top: -1px;
  width: 100%;
}

.btn-group-vertical .btn-modern:first-child {
  border-top-left-radius: var(--radius-md);
  border-top-right-radius: var(--radius-md);
  margin-top: 0;
}

.btn-group-vertical .btn-modern:last-child {
  border-bottom-left-radius: var(--radius-md);
  border-bottom-right-radius: var(--radius-md);
}

/* ========================================
   FLOATING ACTION BUTTON (FAB)
   ======================================== */

.btn-fab {
  position: fixed;
  bottom: var(--space-6);
  right: var(--space-6);
  width: 56px;
  height: 56px;
  padding: 0;
  border-radius: var(--radius-full);
  background: var(--color-primary);
  color: white;
  box-shadow: var(--shadow-lg);
  z-index: var(--z-fixed);
}

.btn-fab:hover {
  box-shadow: var(--shadow-xl);
  transform: translateY(-2px);
}

/* ========================================
   SPECIAL BUTTON STYLES
   ======================================== */

/* Pill Button (Fully Rounded) */
.btn-pill {
  border-radius: var(--radius-full);
}

/* Block Button (Full Width) */
.btn-block {
  width: 100%;
  display: flex;
}

/* Gradient Button */
.btn-gradient {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
  color: white;
  box-shadow: var(--shadow-md);
}

.btn-gradient:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
}

/* Glass Button (Frosted Glass Effect) */
.btn-glass {
  background: rgba(255, 255, 255, 0.1);
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.2);
  color: white;
}

.btn-glass:hover {
  background: rgba(255, 255, 255, 0.2);
  border-color: rgba(255, 255, 255, 0.3);
}

/* ========================================
   BUTTON WITH BADGE
   ======================================== */

.btn-with-badge {
  position: relative;
}

.btn-badge {
  position: absolute;
  top: -6px;
  right: -6px;
  min-width: 20px;
  height: 20px;
  padding: 0 6px;
  background: var(--color-danger);
  color: white;
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: var(--font-semibold);
  display: flex;
  align-items: center;
  justify-content: center;
  border: 2px solid white;
}

.dark .btn-badge {
  border-color: var(--dark-bg-primary);
}

/* ========================================
   RESPONSIVE BEHAVIOR
   ======================================== */

@media (max-width: 768px) {
  .btn-modern {
    padding: var(--space-3) var(--space-4);
    font-size: var(--text-sm);
  }
  
  .btn-lg {
    padding: var(--space-4) var(--space-5);
    font-size: var(--text-base);
  }
  
  .btn-fab {
    bottom: var(--space-4);
    right: var(--space-4);
    width: 48px;
    height: 48px;
  }
}

/* ========================================
   BUTTON PRESETS (Common Use Cases)
   ======================================== */

/* Submit Button */
.btn-submit {
  background: var(--color-success);
  color: white;
  font-weight: var(--font-semibold);
  padding: var(--space-3) var(--space-6);
}

.btn-submit:hover {
  background: var(--color-success-dark);
  box-shadow: var(--shadow-md);
}

/* Cancel Button */
.btn-cancel {
  background: var(--color-gray-200);
  color: var(--color-gray-700);
  font-weight: var(--font-medium);
}

.btn-cancel:hover {
  background: var(--color-gray-300);
}

.dark .btn-cancel {
  background: var(--dark-bg-tertiary);
  color: var(--dark-text-secondary);
}

.dark .btn-cancel:hover {
  background: var(--color-gray-600);
}

/* Delete Button */
.btn-delete {
  background: transparent;
  color: var(--color-danger);
  border: 1px solid var(--color-danger);
}

.btn-delete:hover {
  background: var(--color-danger);
  color: white;
}

/* Link Button (Looks like a link) */
.btn-link {
  background: transparent;
  color: var(--color-primary);
  padding: 0;
  border: none;
  text-decoration: underline;
  font-weight: var(--font-normal);
}

.btn-link:hover {
  color: var(--color-primary-hover);
  text-decoration: none;
  background: transparent;
  transform: none;
}

/* ========================================
   ACCESSIBILITY ENHANCEMENTS
   ======================================== */

.btn-modern:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

.btn-modern[aria-pressed="true"] {
  background: var(--color-primary-dark);
  box-shadow: var(--shadow-inner);
}

/* High Contrast Mode Support */
@media (prefers-contrast: high) {
  .btn-modern {
    border: 2px solid currentColor;
  }
}

/* Reduced Motion Support */
@media (prefers-reduced-motion: reduce) {
  .btn-modern {
    transition: none;
  }
  
  .btn-modern:hover {
    transform: none;
  }
  
  .btn-loading::before {
    animation: none;
  }
}