/* ==========================================================================
   ?? COMPONENT - AppButton
   
   Système de boutons unifié utilisant les variables globales du design system.
   
   BEM Naming Convention:
   - .app-btn                    (Block)
   - .app-btn-Primary            (Modifier - Variante)
   - .app-btn-Secondary          (Modifier - Variante)
   - .app-btn-Small              (Modifier - Taille)
   - .app-btn-group              (Block - Groupe)
   ========================================================================== */

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

.app-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-2);
    border: none;
    border-radius: var(--border-radius-md);
    font-weight: var(--font-weight-medium);
    cursor: pointer;
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    font-family: var(--font-family-sans, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif);
    text-decoration: none;
    white-space: nowrap;
    user-select: none;
    outline: none;
    line-height: var(--line-height-tight);
}

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

.app-btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none !important;
    box-shadow: none !important;
}

.app-btn i {
    font-size: 1em;
    flex-shrink: 0;
}

/* ==========================================================================
   STYLE VARIANTS
   ========================================================================== */

/* === PRIMARY === */
.app-btn-Primary {
    background: linear-gradient(135deg, var(--color-info), var(--color-info-hover));
    color: var(--color-text-inverse);
    box-shadow: 0 2px 8px rgba(59, 130, 246, 0.3);
}

.app-btn-Primary:hover:not(:disabled) {
    background: linear-gradient(135deg, var(--color-info-hover), var(--color-primary-dark));
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.4);
}

.app-btn-Primary:active:not(:disabled) {
    transform: translateY(0);
    box-shadow: 0 1px 4px rgba(59, 130, 246, 0.3);
}

/* === SECONDARY === */
.app-btn-Secondary {
    background: var(--color-gray-100);
    color: var(--color-gray-700);
    border: 1px solid var(--color-border);
}

.app-btn-Secondary:hover:not(:disabled) {
    background: var(--color-gray-200);
    color: var(--color-text-primary);
    border-color: var(--color-gray-300);
}

.app-btn-Secondary:active:not(:disabled) {
    background: var(--color-gray-300);
}

/* === ACCENT === */
.app-btn-Accent {
    background: linear-gradient(135deg, var(--color-success), var(--color-success-hover));
    color: var(--color-text-inverse);
    box-shadow: 0 2px 8px rgba(16, 185, 129, 0.3);
}

.app-btn-Accent:hover:not(:disabled) {
    background: linear-gradient(135deg, var(--color-success-hover), #047857);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(16, 185, 129, 0.4);
}

.app-btn-Accent:active:not(:disabled) {
    transform: translateY(0);
    box-shadow: 0 1px 4px rgba(16, 185, 129, 0.3);
}

/* === DANGER === */
.app-btn-Danger {
    background: linear-gradient(135deg, var(--color-danger), var(--color-danger-hover));
    color: var(--color-text-inverse);
    box-shadow: 0 2px 8px rgba(239, 68, 68, 0.3);
}

.app-btn-Danger:hover:not(:disabled) {
    background: linear-gradient(135deg, var(--color-danger-hover), #b91c1c);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(239, 68, 68, 0.4);
}

.app-btn-Danger:active:not(:disabled) {
    transform: translateY(0);
    box-shadow: 0 1px 4px rgba(239, 68, 68, 0.3);
}

/* === OUTLINE === */
.app-btn-Outline {
    background: transparent;
    color: var(--color-info);
    border: 2px solid var(--color-info);
}

.app-btn-Outline:hover:not(:disabled) {
    background: var(--color-info);
    color: var(--color-text-inverse);
}

.app-btn-Outline:active:not(:disabled) {
    background: var(--color-info-hover);
    border-color: var(--color-info-hover);
}

/* === GHOST === */
.app-btn-Ghost {
    background: transparent;
    color: var(--color-text-secondary);
    border: none;
}

.app-btn-Ghost:hover:not(:disabled) {
    background: var(--color-gray-100);
    color: var(--color-gray-700);
}

.app-btn-Ghost:active:not(:disabled) {
    background: var(--color-gray-200);
}

/* === LINK === */
.app-btn-Link {
    background: transparent;
    color: var(--color-info);
    border: none;
    text-decoration: none;
}

.app-btn-Link:hover:not(:disabled) {
    color: var(--color-info-hover);
    text-decoration: underline;
}

.app-btn-Link:active:not(:disabled) {
    color: var(--color-primary-dark);
}

/* ==========================================================================
   SIZE VARIANTS
   ========================================================================== */

.app-btn-Small {
    padding: var(--spacing-1) var(--spacing-3);
    font-size: var(--font-size-sm);
    min-height: 32px;
}

.app-btn-Small i {
    font-size: 0.875em;
}

.app-btn-Medium {
    padding: var(--spacing-2) var(--spacing-5);
    font-size: var(--font-size-base);
    min-height: 40px;
}

.app-btn-Large {
    padding: var(--spacing-3) var(--spacing-8);
    font-size: var(--font-size-lg);
    min-height: 48px;
}

.app-btn-Large i {
    font-size: 1.1em;
}

/* ==========================================================================
   ADDITIONAL OPTIONS
   ========================================================================== */

.app-btn-full-width {
    width: 100%;
}

/* Loading state */
.app-btn .fa-spinner {
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

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

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

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

.app-btn-group-vertical .app-btn {
    width: 100%;
}

/* ==========================================================================
   DARK MODE (optional)
   ========================================================================== */

@media (prefers-color-scheme: dark) {
    .app-btn-Secondary {
        background: var(--color-gray-700);
        color: var(--color-gray-100);
        border-color: var(--color-gray-600);
    }

    .app-btn-Secondary:hover:not(:disabled) {
        background: var(--color-gray-600);
        color: var(--color-white);
    }

    .app-btn-Ghost {
        color: var(--color-gray-400);
    }

    .app-btn-Ghost:hover:not(:disabled) {
        background: var(--color-gray-700);
        color: var(--color-gray-100);
    }
}

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

@media (max-width: 768px) {
    .app-btn-Medium {
        padding: var(--spacing-2) var(--spacing-4);
        font-size: var(--font-size-sm);
    }

    .app-btn-Large {
        padding: var(--spacing-3) var(--spacing-6);
        font-size: var(--font-size-base);
    }
}