/* Panel System — ПравоАгент */
/* VS Code / Cursor-like panel layout */

.panel-layout {
    display: grid;
    grid-template-columns: var(--panel-activity-width, 48px) var(--panel-sidebar-width, 280px) 1fr var(--panel-right-width, 0px);
    grid-template-rows: 1fr;
    height: 100vh;
    overflow: hidden;
    background: var(--color-bg);
    transition: grid-template-columns var(--transition-base);
}

.panel-layout.sidebar-collapsed {
    --panel-sidebar-width: 0px;
}

.panel-layout.right-collapsed {
    --panel-right-width: 0px;
}

/* Activity Bar */
.panel-activity-bar {
    display: flex;
    flex-direction: column;
    align-items: center;
    background: var(--color-bg-alt);
    border-right: 1px solid var(--color-border);
    padding: var(--space-sm) 0;
    gap: var(--space-xs);
    z-index: 10;
    overflow-y: auto;
}

.activity-bar-item {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: var(--radius-sm);
    color: var(--color-text-muted);
    font-size: var(--font-size-lg);
    cursor: pointer;
    transition: all var(--transition-fast);
    position: relative;
    border: none;
    background: none;
}

.activity-bar-item:hover {
    color: var(--color-text);
    background: var(--color-bg-hover);
}

.activity-bar-item.active {
    color: var(--color-primary-light);
}

.activity-bar-item.active::before {
    content: '';
    position: absolute;
    left: -8px;
    top: 50%;
    transform: translateY(-50%);
    width: 3px;
    height: 20px;
    background: var(--color-primary-light);
    border-radius: 0 2px 2px 0;
}

.activity-bar-bottom {
    margin-top: auto;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-xs);
}

/* Panels */
.panel {
    display: flex;
    flex-direction: column;
    background: var(--color-bg);
    border-right: 1px solid var(--color-border);
    overflow: hidden;
    position: relative;
    min-width: 0;
}

.panel:last-child {
    border-right: none;
}

.panel-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-xs) var(--space-sm);
    background: var(--color-bg-alt);
    border-bottom: 1px solid var(--color-border);
    cursor: grab;
    user-select: none;
    min-height: 36px;
    flex-shrink: 0;
}

.panel-header:active {
    cursor: grabbing;
}

.panel-header-title {
    font-size: var(--font-size-sm);
    font-weight: 600;
    color: var(--color-text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.panel-header-actions {
    display: flex;
    align-items: center;
    gap: 2px;
}

.panel-header-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 24px;
    height: 24px;
    border-radius: var(--radius-sm);
    color: var(--color-text-muted);
    cursor: pointer;
    transition: all var(--transition-fast);
    border: none;
    background: none;
    font-size: 14px;
    padding: 0;
}

.panel-header-btn:hover {
    color: var(--color-text);
    background: var(--color-bg-hover);
}

.panel-body {
    flex: 1;
    overflow: auto;
    padding: var(--space-sm);
}

/* Panel Resize Handle */
.panel-resize-handle {
    position: absolute;
    top: 0;
    right: 0;
    width: 4px;
    height: 100%;
    cursor: col-resize;
    z-index: 20;
    transition: background var(--transition-fast);
}

.panel-resize-handle:hover,
.panel-resize-handle.active {
    background: var(--color-primary-light);
}

.panel-resize-handle::after {
    content: '';
    position: absolute;
    top: 0;
    left: -3px;
    right: -3px;
    bottom: 0;
}

.panel-resize-handle.horizontal {
    top: auto;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 4px;
    cursor: row-resize;
}

/* Tabs within panels */
.panel-tabs {
    display: flex;
    align-items: center;
    background: var(--color-bg-alt);
    border-bottom: 1px solid var(--color-border);
    flex-shrink: 0;
    overflow-x: auto;
    scrollbar-width: none;
}

.panel-tabs::-webkit-scrollbar {
    display: none;
}

.panel-tab {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
    padding: var(--space-xs) var(--space-md);
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
    cursor: pointer;
    border-bottom: 2px solid transparent;
    transition: all var(--transition-fast);
    white-space: nowrap;
    user-select: none;
    border-right: 1px solid transparent;
    position: relative;
}

.panel-tab:hover {
    color: var(--color-text);
    background: var(--color-bg-hover);
}

.panel-tab.active {
    color: var(--color-text);
    border-bottom-color: var(--color-primary-light);
    background: var(--color-bg);
}

.panel-tab-close {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 16px;
    height: 16px;
    border-radius: 2px;
    font-size: 12px;
    color: var(--color-text-muted);
    cursor: pointer;
    transition: all var(--transition-fast);
    border: none;
    background: none;
    padding: 0;
    opacity: 0;
}

.panel-tab:hover .panel-tab-close {
    opacity: 1;
}

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

/* Panel Sections (grouped content within a panel) */
.panel-section {
    margin-bottom: var(--space-md);
}

.panel-section-title {
    font-size: var(--font-size-sm);
    font-weight: 600;
    color: var(--color-text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    padding: var(--space-xs) var(--space-sm);
    margin-bottom: var(--space-xs);
}

.panel-section-item {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-xs) var(--space-sm);
    border-radius: var(--radius-sm);
    color: var(--color-text-secondary);
    font-size: var(--font-size-sm);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.panel-section-item:hover {
    color: var(--color-text);
    background: var(--color-bg-hover);
}

.panel-section-item.active {
    color: var(--color-text);
    background: var(--color-bg-hover);
}

.panel-section-item .item-icon {
    width: 16px;
    text-align: center;
    flex-shrink: 0;
}

/* Split panels */
.panel-split {
    display: flex;
    flex: 1;
    overflow: hidden;
}

.panel-split.horizontal {
    flex-direction: column;
}

.panel-split > .panel {
    border-right: none;
    border-bottom: 1px solid var(--color-border);
}

.panel-split.horizontal > .panel:last-child {
    border-bottom: none;
}

/* Collapsed panel indicators */
.panel-collapsed {
    width: 0 !important;
    overflow: hidden;
    padding: 0;
    border: none;
    min-width: 0;
    flex: 0 0 0 !important;
}

/* Animations */
@keyframes panelSlideIn {
    from {
        transform: translateX(-100%);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}

@keyframes panelFadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.panel-enter {
    animation: panelFadeIn var(--transition-base) ease;
}

/* Workspace panel header with icon */
.panel-header-icon {
    width: 20px;
    text-align: center;
    flex-shrink: 0;
}

/* Empty state in panel */
.panel-empty {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: var(--space-xl);
    color: var(--color-text-muted);
    text-align: center;
    gap: var(--space-sm);
    height: 100%;
}

.panel-empty-icon {
    font-size: 2rem;
    opacity: 0.5;
}

.panel-empty-text {
    font-size: var(--font-size-sm);
    max-width: 200px;
}

/* Responsive */
@media (max-width: 768px) {
    .panel-layout {
        grid-template-columns: 1fr;
        grid-template-rows: auto 1fr;
    }

    .panel-activity-bar {
        flex-direction: row;
        padding: 0 var(--space-sm);
        border-right: none;
        border-bottom: 1px solid var(--color-border);
        height: 48px;
    }

    .activity-bar-bottom {
        margin-top: 0;
        flex-direction: row;
        margin-left: auto;
    }

    .activity-bar-item.active::before {
        left: 50%;
        top: auto;
        bottom: 0;
        transform: translateX(-50%);
        width: 20px;
        height: 3px;
    }

    .panel-resize-handle {
        display: none;
    }
}