/* ==========================================================================
   Buttons — Action triggers and interactive controls
   Layer 5 — Component (requires tokens.css, base.css)
   /css/admin/buttons.css

   Purpose: Primary, secondary, success, danger, ghost, and outline button
   variants used across all admin views. Includes size variants, icon-only
   buttons, button groups, and loading/spinner states.
   ========================================================================== */

/* ==========================================================================
   1. Base Button
   ========================================================================== */

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-1-5);
    padding: var(--spacing-2-5) var(--spacing-5);
    font-size: var(--text-sm);
    font-weight: var(--font-medium);
    font-family: inherit;
    line-height: var(--leading-snug);
    text-decoration: none;
    border: 1px solid transparent;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
    white-space: nowrap;
}

.btn:focus {
    outline: none;
    box-shadow: 0 0 0 var(--size-focus-ring) var(--color-focus-ring);
}

.btn:disabled {
    opacity: var(--opacity-disabled);
    cursor: not-allowed;
}

/* ==========================================================================
   2. Size Variants
   ========================================================================== */

.btn-sm {
    padding: var(--spacing-1-5) var(--spacing-3);
    font-size: var(--text-xs);
}

.btn-lg {
    padding: var(--spacing-3-5) var(--spacing-7);
    font-size: var(--text-base);
}

/* ==========================================================================
   3. Color Variants
   ========================================================================== */

/* Primary — Main actions (Save, Submit) */
.btn-primary {
    background: var(--color-primary);
    color: var(--color-white);
    border-color: var(--color-primary);
}

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

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

/* Secondary — Secondary actions (Cancel, Back) */
.btn-secondary {
    background: var(--color-secondary);
    color: var(--color-secondary-text);
    border-color: var(--color-secondary-border);
}

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

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

/* Success — Positive actions (Publish, Approve) */
.btn-success {
    background: var(--color-success);
    color: var(--color-white);
    border-color: var(--color-success);
}

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

.btn-success:active:not(:disabled) {
    background: var(--color-success-active);
}

/* Danger — Destructive actions (Delete, Remove) */
.btn-danger {
    background: var(--color-danger);
    color: var(--color-white);
    border-color: var(--color-danger);
}

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

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

/* Ghost — Subtle actions (View Original) */
.btn-ghost {
    background: transparent;
    color: var(--color-text-muted);
    border-color: transparent;
}

.btn-ghost:hover:not(:disabled) {
    background: var(--color-surface-hover);
    color: var(--color-text-bright);
}

/* ==========================================================================
   4. Outline Variants
   ========================================================================== */

.btn-outline-primary {
    background: transparent;
    color: var(--color-primary-light);
    border-color: var(--color-primary-mid);
}

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

.btn-outline-success {
    background: transparent;
    color: var(--color-success-light);
    border-color: var(--color-success-mid);
}

.btn-outline-success:hover:not(:disabled) {
    background: var(--color-success);
    color: var(--color-white);
}

.btn-outline-danger {
    background: transparent;
    color: var(--color-danger-text);
    border-color: var(--color-danger-border);
}

.btn-outline-danger:hover:not(:disabled) {
    background: var(--color-danger);
    color: var(--color-white);
}

/* ==========================================================================
   5. Icon-Only Button
   ========================================================================== */

.btn-icon {
    padding: var(--spacing-2);
}

.btn-icon.btn-sm {
    padding: var(--spacing-1-5);
}

/* ==========================================================================
   6. Button Group
   ========================================================================== */

.btn-group {
    display: inline-flex;
    gap: var(--spacing-2);
}

.btn-group-tight {
    gap: 0;
}

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

.btn-group-tight .btn:first-child {
    border-radius: var(--radius-md) 0 0 var(--radius-md);
}

.btn-group-tight .btn:last-child {
    border-radius: 0 var(--radius-md) var(--radius-md) 0;
}

.btn-group-tight .btn:not(:last-child) {
    border-right-width: 0;
}

/* ==========================================================================
   7. Loading / Spinner State
   NOTE: `!important` on color is required — overrides variant text color
   so only the pseudo-element spinner is visible.
   ========================================================================== */

.btn-loading {
    position: relative;
    color: transparent !important;
}

.btn-loading::after {
    content: '';
    position: absolute;
    width: var(--size-spinner);
    height: var(--size-spinner);
    border: var(--size-spinner-border) solid currentColor;
    border-right-color: transparent;
    border-radius: 50%;
    animation: spin var(--duration-spin) linear infinite;
}

.btn-primary.btn-loading::after,
.btn-success.btn-loading::after,
.btn-danger.btn-loading::after {
    border-color: var(--color-spinner-track);
    border-right-color: var(--color-white);
}

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