/*
 * Button Component Styles
 *
 * A comprehensive button system with variants, sizes, and states.
 * Uses the design system tokens for consistent styling.
 *
 * Variants:
 *   - .btn-primary    : Main call-to-action, brand color
 *   - .btn-secondary  : Secondary actions, neutral color
 *   - .btn-danger     : Destructive actions, error color
 *   - .btn-ghost      : Minimal style, transparent background
 *
 * Sizes:
 *   - .btn-sm         : Small (compact UI, tables)
 *   - (default)       : Medium (standard use)
 *   - .btn-lg         : Large (hero sections, emphasis)
 *
 * States:
 *   - :hover          : Mouse hover
 *   - :active         : Button pressed
 *   - :disabled       : Disabled state
 *   - :focus-visible  : Keyboard focus
 *
 * Usage examples:
 *   <button class="btn btn-primary">Submit</button>
 *   <button class="btn btn-secondary btn-sm">Cancel</button>
 *   <a href="#" class="btn btn-danger btn-lg">Delete</a>
 *   <button class="btn btn-ghost" disabled>Disabled</button>
 */

/* ============================================
 * BASE BUTTON STYLES
 * Common styles for all button variants
 * ============================================ */
.btn {
  /* Layout */
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);

  /* Sizing - Medium (default) */
  padding: var(--space-2-5) var(--space-4);
  min-height: 38px;

  /* Typography */
  font-family: var(--font-family-sans);
  font-size: 0.875rem;
  font-weight: 500;
  line-height: 1.25;
  text-decoration: none;
  white-space: nowrap;

  /* Appearance */
  border: 1px solid transparent;
  border-radius: 6px;
  cursor: pointer;

  /* Transitions */
  transition:
    background-color 0.15s ease,
    border-color 0.15s ease,
    color 0.15s ease,
    box-shadow 0.15s ease,
    transform 0.1s ease;

  /* Prevent text selection on double-click */
  user-select: none;
}

/* Focus state - consistent for all variants */
.btn:focus-visible {
  outline: none;
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.3);
}

/* Active state - slight press effect */
.btn:active:not(:disabled) {
  transform: translateY(1px);
}

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

/* Primary Button - Main call-to-action */
.btn-primary {
  background-color: var(--color-primary-500);
  border-color: var(--color-primary-500);
  color: var(--color-neutral-white);
}

.btn-primary:hover:not(:disabled) {
  background-color: var(--color-primary-600);
  border-color: var(--color-primary-600);
}

.btn-primary:active:not(:disabled) {
  background-color: var(--color-primary-700);
  border-color: var(--color-primary-700);
}

.btn-primary:disabled {
  background-color: var(--color-primary-300);
  border-color: var(--color-primary-300);
  cursor: not-allowed;
  opacity: 0.7;
}

/* Secondary Button - Secondary actions */
.btn-secondary {
  background-color: var(--color-neutral-white);
  border-color: var(--color-neutral-300);
  color: var(--color-neutral-700);
}

.btn-secondary:hover:not(:disabled) {
  background-color: var(--color-neutral-50);
  border-color: var(--color-neutral-400);
}

.btn-secondary:active:not(:disabled) {
  background-color: var(--color-neutral-100);
  border-color: var(--color-neutral-400);
}

.btn-secondary:disabled {
  background-color: var(--color-neutral-50);
  border-color: var(--color-neutral-200);
  color: var(--color-neutral-400);
  cursor: not-allowed;
}

/* Danger Button - Destructive actions */
.btn-danger {
  background-color: var(--color-error-600);
  border-color: var(--color-error-600);
  color: var(--color-neutral-white);
}

.btn-danger:hover:not(:disabled) {
  background-color: var(--color-error-700);
  border-color: var(--color-error-700);
}

.btn-danger:active:not(:disabled) {
  background-color: var(--color-error-800);
  border-color: var(--color-error-800);
}

.btn-danger:disabled {
  background-color: var(--color-error-300);
  border-color: var(--color-error-300);
  cursor: not-allowed;
  opacity: 0.7;
}

.btn-danger:focus-visible {
  box-shadow: 0 0 0 3px rgba(220, 38, 38, 0.3);
}

/* Ghost Button - Minimal, transparent */
.btn-ghost {
  background-color: transparent;
  border-color: transparent;
  color: var(--color-neutral-700);
}

.btn-ghost:hover:not(:disabled) {
  background-color: var(--color-neutral-100);
}

.btn-ghost:active:not(:disabled) {
  background-color: var(--color-neutral-200);
}

.btn-ghost:disabled {
  color: var(--color-neutral-400);
  cursor: not-allowed;
}

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

/* Small Button */
.btn-sm {
  padding: var(--space-1-5) var(--space-3);
  min-height: 30px;
  font-size: 0.8125rem;
  border-radius: 4px;
}

/* Large Button */
.btn-lg {
  padding: var(--space-3) var(--space-6);
  min-height: 46px;
  font-size: 1rem;
  border-radius: 8px;
}

/* ============================================
 * BUTTON MODIFIERS
 * ============================================ */

/* Full width button */
.btn-block {
  display: flex;
  width: 100%;
}

/* Icon-only button (square) */
.btn-icon {
  padding: var(--space-2-5);
  min-width: 38px;
}

.btn-icon.btn-sm {
  padding: var(--space-1-5);
  min-width: 30px;
}

.btn-icon.btn-lg {
  padding: var(--space-3);
  min-width: 46px;
}

/* ============================================
 * BUTTON GROUP
 * For grouping related buttons together
 * ============================================ */
.btn-group {
  display: inline-flex;
  gap: var(--space-2);
}

.btn-group-vertical {
  display: inline-flex;
  flex-direction: column;
  gap: var(--space-2);
}

/* Connected button group (no gap, shared borders) */
.btn-group-connected {
  display: inline-flex;
}

.btn-group-connected .btn {
  border-radius: 0;
}

.btn-group-connected .btn:first-child {
  border-radius: 6px 0 0 6px;
}

.btn-group-connected .btn:last-child {
  border-radius: 0 6px 6px 0;
}

.btn-group-connected .btn:not(:first-child) {
  margin-left: -1px;
}

.btn-group-connected .btn:hover,
.btn-group-connected .btn:focus-visible {
  z-index: 1;
}

/* ============================================
 * DARK MODE OVERRIDES
 * ============================================ */

/* Secondary Button */
.dark .btn-secondary {
  background-color: var(--color-slate-800);
  border-color: var(--color-border-dark);
  color: var(--color-slate-200);
}

.dark .btn-secondary:hover:not(:disabled) {
  background-color: var(--color-slate-700);
  border-color: var(--color-slate-600);
}

.dark .btn-secondary:active:not(:disabled) {
  background-color: var(--color-slate-600);
  border-color: var(--color-slate-500);
}

.dark .btn-secondary:disabled {
  background-color: var(--color-slate-900);
  border-color: var(--color-border-dark);
  color: var(--color-slate-600);
}

/* Ghost Button */
.dark .btn-ghost {
  color: var(--color-slate-300);
}

.dark .btn-ghost:hover:not(:disabled) {
  background-color: var(--color-slate-800);
  color: var(--color-slate-100);
}

.dark .btn-ghost:active:not(:disabled) {
  background-color: var(--color-slate-700);
}