/* ============================================================
   15. MODALS
   ============================================================ */

.modal-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: var(--z-modal);
    padding: var(--space-4);
    animation: fadeIn 150ms ease;
}

.modal-container {
    background: var(--color-surface);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-lg);
    width: 100%;
    max-width: 520px;
    max-height: 90vh;
    overflow-y: auto;
    animation: modalSlideIn 200ms ease;
}

@keyframes modalSlideIn {
    from { opacity: 0; transform: translateY(-10px) scale(0.98); }
    to { opacity: 1; transform: translateY(0) scale(1); }
}

.modal-sm { max-width: 380px; }
.modal-md { max-width: 520px; }
.modal-lg { max-width: 720px; }
.modal-xl { max-width: 960px; }

.modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-5) var(--space-5) var(--space-3);
}

.modal-header h3 {
    font-size: var(--text-lg);
    font-weight: 600;
}

.modal-close {
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--border-radius);
    color: var(--color-text-muted);
    font-size: var(--text-xl);
    transition: background var(--transition), color var(--transition);
}

.modal-close:hover {
    background: var(--color-bg);
    color: var(--color-text);
}

.modal-body {
    padding: var(--space-3) var(--space-5) var(--space-5);
}

.modal-footer {
    display: flex;
    align-items: center;
    justify-content: flex-end;
    gap: var(--space-3);
    padding: var(--space-4) var(--space-5);
    border-top: 1px solid var(--color-border);
}


/* ============================================================
   16. TOAST NOTIFICATIONS
   ============================================================ */

.toast-container {
    position: fixed;
    top: var(--space-4);
    right: var(--space-4);
    z-index: var(--z-toast);
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
    pointer-events: none;
    max-width: 400px;
    width: 100%;
}

.toast {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    padding: var(--space-3) var(--space-4);
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-md);
    pointer-events: auto;
    opacity: 0;
    transform: translateX(100%);
    transition: opacity var(--transition-slow), transform var(--transition-slow);
}

.toast.show {
    opacity: 1;
    transform: translateX(0);
}

.toast.hide {
    opacity: 0;
    transform: translateX(100%);
}

.toast-icon {
    width: 24px;
    height: 24px;
    border-radius: var(--border-radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: var(--text-xs);
    font-weight: 700;
    flex-shrink: 0;
}

.toast-success .toast-icon {
    background: var(--color-success-light);
    color: var(--color-success);
}

.toast-danger .toast-icon {
    background: var(--color-danger-light);
    color: var(--color-danger);
}

.toast-warning .toast-icon {
    background: var(--color-warning-light);
    color: var(--color-warning);
}

.toast-info .toast-icon {
    background: var(--color-info-light);
    color: var(--color-info);
}

.toast-message {
    flex: 1;
    font-size: var(--text-sm);
    color: var(--color-text);
}

.toast-close {
    color: var(--color-text-muted);
    font-size: var(--text-lg);
    padding: 0 var(--space-1);
    cursor: pointer;
    transition: color var(--transition);
    background: none;
    border: none;
    line-height: 1;
}

.toast-close:hover {
    color: var(--color-text);
}


/* ============================================================
   17. LOADING & SPINNER
   ============================================================ */

.spinner {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 2px solid var(--color-border);
    border-top-color: var(--color-primary);
    border-radius: 50%;
    animation: spin 600ms linear infinite;
}

.spinner-lg {
    width: 32px;
    height: 32px;
    border-width: 3px;
}

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

.loading-overlay {
    display: flex;
    align-items: center;
    justify-content: center;
    flex-direction: column;
    gap: var(--space-3);
    padding: var(--space-12);
    color: var(--color-text-muted);
}

.loading-overlay .spinner {
    width: 28px;
    height: 28px;
}


/* ============================================================
   18. EMPTY STATE & PLACEHOLDER
   ============================================================ */

.empty-state {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: var(--space-12) var(--space-6);
    color: var(--color-text-muted);
}

.empty-state .empty-title {
    font-size: var(--text-md);
    font-weight: 600;
    color: var(--color-text-secondary);
    margin-bottom: var(--space-2);
}

.empty-state .empty-description {
    font-size: var(--text-sm);
    max-width: 360px;
    margin-bottom: var(--space-4);
}


/* ============================================================
   19. UTILITIES
   ============================================================ */

.hidden { display: none !important; }
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    border: 0;
}

.flex { display: flex; }
.flex-col { flex-direction: column; }
.flex-wrap { flex-wrap: wrap; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.justify-center { justify-content: center; }
.justify-end { justify-content: flex-end; }
.gap-1 { gap: var(--space-1); }
.gap-2 { gap: var(--space-2); }
.gap-3 { gap: var(--space-3); }
.gap-4 { gap: var(--space-4); }
.gap-6 { gap: var(--space-6); }

.w-full { width: 100%; }
.text-right { text-align: right; }
.text-center { text-align: center; }
.text-left { text-align: left; }

.mt-1 { margin-top: var(--space-1); }
.mt-2 { margin-top: var(--space-2); }
.mt-3 { margin-top: var(--space-3); }
.mt-4 { margin-top: var(--space-4); }
.mt-6 { margin-top: var(--space-6); }
.mb-1 { margin-bottom: var(--space-1); }
.mb-2 { margin-bottom: var(--space-2); }
.mb-3 { margin-bottom: var(--space-3); }
.mb-4 { margin-bottom: var(--space-4); }
.mb-6 { margin-bottom: var(--space-6); }

.p-4 { padding: var(--space-4); }
.p-5 { padding: var(--space-5); }

.truncate {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.no-select { user-select: none; }
.pointer { cursor: pointer; }

.ml-1 { margin-left: var(--space-1); }
.ml-2 { margin-left: var(--space-2); }
.ml-3 { margin-left: var(--space-3); }
.mr-1 { margin-right: var(--space-1); }
.mr-2 { margin-right: var(--space-2); }
.mr-3 { margin-right: var(--space-3); }

.font-semibold { font-weight: 600; }
.font-bold { font-weight: 700; }
.text-sm { font-size: var(--text-sm); }
.text-xs { font-size: var(--text-xs); }