/*
 * 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>
 */

@layer components {

/* ============================================
 * 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-block-size: 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 var(--color-focus-strong);
  }

  /* 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);
  }

  /* stylelint-disable-next-line no-descending-specificity */
  .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-bg-secondary);
  border-color: var(--color-border-secondary);
  color: var(--color-text-strong);
}

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

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

  /* stylelint-disable-next-line no-descending-specificity */
  .btn-secondary:disabled {
    background-color: var(--color-bg-subtle);
    border-color: var(--color-border-primary);
    color: var(--color-text-muted);
    cursor: not-allowed;
  }

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

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

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

  /* stylelint-disable-next-line no-descending-specificity */
  .btn.btn-danger:disabled {
    background-color: var(--color-error-300);
    border-color: var(--color-error-300);
    cursor: not-allowed;
    opacity: 0.7;
  }

  /* stylelint-disable-next-line no-descending-specificity */
  .btn.btn-danger:focus-visible {
    box-shadow: 0 0 0 3px var(--focus-ring-error-strong);
  }

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

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

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

  /* stylelint-disable-next-line no-descending-specificity */
  .btn-ghost:disabled {
    color: var(--color-text-muted);
    cursor: not-allowed;
  }

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

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

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

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

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

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

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

  .btn-icon.btn-lg {
    padding: var(--space-3);
    min-inline-size: 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;
}

  /* stylelint-disable-next-line no-descending-specificity */
  .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-inline-start: -1px;
    }

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

/* stylelint-disable no-descending-specificity -- dark mode override for ghost active state */
html[data-theme="dark"] .btn-ghost:active:not(:disabled) {
  background-color: var(--color-slate-700);
}
/* stylelint-enable no-descending-specificity */

/* ============================================
 * SPLIT BUTTON
 * A two-part button: main action + dropdown trigger.
 * The main button inherits from any .btn variant (e.g. .btn-secondary).
 * The trigger shows a caret/arrow to open a dropdown.
 *
 * Structure:
 *   <div class="btn-split">
 *     <button class="btn btn-secondary btn-sm">Label</button>
 *     <button class="btn btn-secondary btn-sm btn-split__trigger">▾</button>
 *   </div>
 *
 * Active state modifier:
 *   Add .btn-split--active to the container to highlight both parts
 *   (e.g. "Watching" state on a watch button).
 * ============================================ */
.btn-split {
  position: relative;
  display: inline-flex;
  align-items: stretch;

  & > .btn:first-child {
    border-start-end-radius: 0;
    border-end-end-radius: 0;
    border-inline-end: none;
  }

  & > .btn-split__trigger {
    border-start-start-radius: 0;
    border-end-start-radius: 0;
  }

  /* When main button is hovered, update trigger border to match */
  & > .btn:first-child:hover:not(:disabled) + .btn-split__trigger {
    border-color: var(--color-neutral-400);
  }
}

/* Active state — accent colours for both parts */
.btn-split--active {
  & > .btn:first-child {
    background-color: var(--color-bg-accent);
    border-color: var(--color-status-info-border);
    color: var(--color-text-accent);

    &:hover {
      background-color: var(--color-bg-accent-hover);
      border-color: var(--color-primary-400);
    }

    & svg {
      color: var(--color-text-accent-bright);
    }
  }

  /* stylelint-disable-next-line no-descending-specificity */
  & > .btn-split__trigger {
    background-color: var(--color-bg-accent);
    color: var(--color-text-accent);
    border-color: var(--color-status-info-border);

    &:hover {
      background-color: var(--color-bg-accent-hover);
      border-color: var(--color-primary-400);
    }
  }

  /* When active main button is hovered, update trigger border to match */
  /* stylelint-disable-next-line no-descending-specificity */
  & > .btn:first-child:hover:not(:disabled) + .btn-split__trigger {
    border-color: var(--color-primary-400);
  }
}

} /* @layer components */