/* =====================================================================
   iQX Engineering Layout - Professional 5-Panel Desktop Layout
   Enterprise Engineering Design System - Light Theme
   ===================================================================== */



:root {
    /* -- Background Hierarchy -- */
    --vm-bg-primary: #F3F5F7;
    --vm-bg-secondary: #FFFFFF;
    --vm-bg-tertiary: #FAFBFC;
    --vm-bg-panel: #FFFFFF;
    --vm-bg-input: #FFFFFF;
    --vm-bg-hover: #EEF2F5;
    --vm-bg-active: #DCE8F5;
    --vm-bg-selected: #DCE8F5;
    --vm-bg-header: #FFFFFF;
    /* -- Borders -- */
    --vm-border: #D5DBE3;
    --vm-border-light: #E5E9EE;
    --vm-border-focus: #2F6BFF;
    --vm-border-strong: #B9C2CC;
    /* -- Text -- */
    --vm-text-primary: #1F2933;
    --vm-text-secondary: #52606D;
    --vm-text-muted: #7B8794;
    --vm-text-accent: #2F6BFF;
    --vm-text-bright: #1F2933;
    --vm-text-disabled: #A0AEC0;
    /* -- Accent Colors -- */
    --vm-accent: #2F6BFF;
    --vm-accent-hover: #1A56DB;
    --vm-success: #4C956C;
    --vm-warning: #C69026;
    --vm-danger: #C05656;
    --vm-info: #3C91B3;
    /* -- Tree Node / Relation Colors -- */
    --vm-variant-color: #2F6BFF;
    --vm-option-color: #4C956C;
    --vm-exclude-color: #C05656;
    --vm-mandatory-color: #355C7D;
    --vm-ifthen-color: #3C91B3;
    --vm-eliminate-color: #9B2C2C;
    --vm-default-color: #718096;
    /* -- Sizing -- */
    --vm-header-height: 48px;
    --vm-sidebar-width: 48px;
    --vm-sidebar-expanded: 220px;
    --vm-explorer-width: 300px;
    --vm-details-width: 280px;
    --vm-font-size: 13px;
    --vm-font-mono: 'Consolas', 'Courier New', monospace;
    --vm-font-ui: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --vm-row-height: 24px;
    --vm-compact-gap: 4px;
    /* -- Theme-aware rgba helpers -- */
    --vm-shadow-color: rgba(0,0,0,0.12);
    --vm-overlay-subtle: rgba(0,0,0,0.04);
    --vm-overlay-light: rgba(0,0,0,0.05);
    --vm-overlay-medium: rgba(0,0,0,0.06);
    --vm-scrollbar-thumb: rgba(0,0,0,0.12);
    --vm-scrollbar-thumb-hover: rgba(0,0,0,0.2);
    /* -- Matrix cell backgrounds -- */
    --vm-matrix-mandatory: #DCE8F5;
    --vm-matrix-exclude: #F8D7DA;
    --vm-matrix-ifthen: #D9F0E3;
    --vm-matrix-eliminate: #FBE7C6;
    --vm-matrix-highlight: #EDF2F7;
    /* -- Table row hover -- */
    --vm-row-hover: #F5F8FA;
}

/* =============================================
   DARK THEME
   ============================================= */
[data-theme="dark"] {
    --vm-bg-primary: #1e1e1e;
    --vm-bg-secondary: #252526;
    --vm-bg-tertiary: #2d2d30;
    --vm-bg-panel: #1e1e1e;
    --vm-bg-input: #3c3c3c;
    --vm-bg-hover: #2a2d2e;
    --vm-bg-active: #37373d;
    --vm-bg-selected: #094771;
    --vm-bg-header: #323233;
    --vm-border: #3e3e42;
    --vm-border-light: #2d2d30;
    --vm-border-focus: #007acc;
    --vm-border-strong: #555;
    --vm-text-primary: #cccccc;
    --vm-text-secondary: #969696;
    --vm-text-muted: #6a6a6a;
    --vm-text-accent: #4fc1ff;
    --vm-text-bright: #e8e8e8;
    --vm-text-disabled: #555;
    --vm-accent: #007acc;
    --vm-accent-hover: #1a8ad4;
    --vm-success: #4ec9b0;
    --vm-warning: #dcdcaa;
    --vm-danger: #f14c4c;
    --vm-info: #75beff;
    --vm-variant-color: #569cd6;
    --vm-option-color: #6a9955;
    --vm-exclude-color: #f14c4c;
    --vm-mandatory-color: #4fc1ff;
    --vm-ifthen-color: #dcdcaa;
    --vm-eliminate-color: #d16969;
    --vm-default-color: #808080;
    --vm-shadow-color: rgba(0,0,0,0.5);
    --vm-overlay-subtle: rgba(255,255,255,0.03);
    --vm-overlay-light: rgba(255,255,255,0.05);
    --vm-overlay-medium: rgba(255,255,255,0.06);
    --vm-scrollbar-thumb: rgba(255,255,255,0.1);
    --vm-scrollbar-thumb-hover: rgba(255,255,255,0.2);
    --vm-matrix-mandatory: rgba(79, 193, 255, 0.25);
    --vm-matrix-exclude: rgba(241, 76, 76, 0.25);
    --vm-matrix-ifthen: rgba(220, 220, 170, 0.25);
    --vm-matrix-eliminate: rgba(209, 105, 105, 0.25);
    --vm-matrix-highlight: rgba(255, 255, 255, 0.03);
    --vm-row-hover: rgba(255, 255, 255, 0.04);
}

/* === THEME-AWARE LOGO === */
.logo-light {
    display: inline;
}

.logo-dark {
    display: none;
}

[data-theme="dark"] .logo-light {
    display: none;
}

[data-theme="dark"] .logo-dark {
    display: inline;
}

/* === GLOBAL BASE === */
html, body {
    margin: 0;
    padding: 0;
    width: 100%;
    height: 100%;
    background: var(--vm-bg-primary);
    color: var(--vm-text-primary);
    font-family: var(--vm-font-ui);
    font-size: var(--vm-font-size);
    box-sizing: border-box;
}

*, *::before, *::after {
    box-sizing: border-box;
}

/* === RESET === */
.vm-app * {
    box-sizing: border-box;
}

.vm-app {
    display: grid;
    grid-template-rows: var(--vm-header-height) 1fr;
    grid-template-columns: var(--vm-sidebar-width) var(--vm-explorer-width) 1fr var(--vm-details-width);
    grid-template-areas:
        "header  header   header  header"
        "sidebar explorer main    details";
    width: 100vw;
    height: 100vh;
    overflow: hidden;
    font-family: var(--vm-font-ui);
    font-size: var(--vm-font-size);
    color: var(--vm-text-primary);
    background: var(--vm-bg-primary);
}

    .vm-app.details-collapsed {
        grid-template-columns: var(--vm-sidebar-width) var(--vm-explorer-width) 1fr 0px;
    }

    .vm-app.sidebar-expanded {
        grid-template-columns: var(--vm-sidebar-expanded) var(--vm-explorer-width) 1fr var(--vm-details-width);
    }

        .vm-app.sidebar-expanded .vm-sidebar-icon {
            width: auto;
            padding: 0 12px;
            justify-content: flex-start;
            gap: 8px;
        }

.vm-sidebar-label {
    display: none;
    font-size: 11px;
    white-space: nowrap;
}

.vm-app.sidebar-expanded .vm-sidebar-label {
    display: inline;
}

/* === NAV SIDEBAR (tree-style navigation) === */

.vm-nav-sidebar {
    display: flex;
    flex-direction: column;
    overflow-y: auto;
    overflow-x: hidden;
    padding: 4px 0;
    font-size: 11px;
}

.vm-nav-section {
    margin-bottom: 2px;
}

.vm-nav-section-header {
    display: flex;
    align-items: center;
    gap: 4px;
    padding: 4px 8px;
    font-size: 10px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--vm-text-secondary);
    cursor: pointer;
    user-select: none;
}

    .vm-nav-section-header:hover {
        color: var(--vm-text-primary);
    }

    .vm-nav-section-header .nav-toggle {
        font-size: 9px;
        width: 12px;
        text-align: center;
        color: var(--vm-text-muted);
    }

.vm-nav-item {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 3px 8px 3px 24px;
    cursor: pointer;
    color: var(--vm-text-primary);
    border-left: 2px solid transparent;
    white-space: nowrap;
    overflow: hidden;
}

    .vm-nav-item:hover {
        background: var(--vm-bg-hover);
    }

    .vm-nav-item.active {
        background: var(--vm-bg-active);
        border-left-color: var(--vm-accent);
        color: var(--vm-text-bright);
    }

    .vm-nav-item .nav-item-icon {
        font-size: 12px;
        width: 16px;
        text-align: center;
        flex-shrink: 0;
    }

    .vm-nav-item .nav-item-label {
        flex: 1;
        overflow: hidden;
        text-overflow: ellipsis;
    }

    .vm-nav-item .nav-item-badge {
        font-size: 9px;
        padding: 0 4px;
        border-radius: 8px;
        background: var(--vm-overlay-medium);
        color: var(--vm-text-muted);
        flex-shrink: 0;
    }

/* =============================================
   1. TOP HEADER BAR
   ============================================= */

.vm-header {
    grid-area: header;
    display: flex;
    align-items: center;
    height: var(--vm-header-height);
    background: var(--vm-bg-header);
    border-bottom: 1px solid var(--vm-border);
    padding: 0 8px;
    gap: 8px;
    z-index: 100;
    user-select: none;
}

.vm-header-brand {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 0 8px;
    color: var(--vm-text-bright);
    text-decoration: none;
    font-weight: 600;
    font-size: 13px;
    white-space: nowrap;
}

    .vm-header-brand img {
        height: 18px;
        opacity: 0.9;
    }

.vm-header-breadcrumb {
    display: flex;
    align-items: center;
    gap: 4px;
    font-size: 12px;
    color: var(--vm-text-secondary);
    flex: 1;
    min-width: 0;
    overflow: hidden;
}

    .vm-header-breadcrumb span {
        white-space: nowrap;
        overflow: hidden;
        text-overflow: ellipsis;
    }

    .vm-header-breadcrumb .bc-sep {
        color: var(--vm-text-muted);
        flex-shrink: 0;
    }

    .vm-header-breadcrumb .bc-active {
        color: var(--vm-text-bright);
    }

.vm-header-actions {
    display: flex;
    align-items: center;
    gap: 2px;
    flex-shrink: 0;
}

.vm-header-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 28px;
    height: 28px;
    border: none;
    background: transparent;
    color: var(--vm-text-secondary);
    border-radius: 4px;
    cursor: pointer;
    font-size: 14px;
}

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

.vm-header-sep {
    width: 1px;
    height: 20px;
    background: var(--vm-border);
    margin: 0 4px;
}

.vm-header-search {
    display: flex;
    align-items: center;
    background: var(--vm-bg-tertiary);
    border: 1px solid var(--vm-border);
    border-radius: 4px;
    padding: 0 8px;
    height: 24px;
    width: 200px;
}

    .vm-header-search input {
        background: transparent;
        border: none;
        color: var(--vm-text-primary);
        font-size: 11px;
        outline: none;
        width: 100%;
    }

        .vm-header-search input::placeholder {
            color: var(--vm-text-muted);
        }

    .vm-header-search:focus-within {
        border-color: var(--vm-border-focus);
        box-shadow: 0 0 0 2px rgba(47, 107, 255, 0.1);
    }

/* =============================================
   2. LEFT SIDEBAR (PRIMARY NAVIGATION)
   ============================================= */

.vm-sidebar {
    grid-area: sidebar;
    display: flex;
    flex-direction: column;
    background: var(--vm-bg-secondary);
    border-right: 1px solid var(--vm-border);
    overflow: hidden;
    user-select: none;
}

.vm-sidebar-icons {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 4px 0;
    gap: 2px;
}

.vm-sidebar-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border: none;
    background: transparent;
    color: var(--vm-text-muted);
    border-radius: 0;
    cursor: pointer;
    border-left: 2px solid transparent;
    font-size: 18px;
    transition: color 0.1s;
}

    .vm-sidebar-icon:hover {
        color: var(--vm-text-primary);
        background: var(--vm-bg-hover);
    }

    .vm-sidebar-icon.active {
        color: var(--vm-accent);
        border-left-color: var(--vm-accent);
        background: var(--vm-bg-active);
    }

    .vm-sidebar-icon svg {
        width: 20px;
        height: 20px;
    }

.vm-sidebar-sep {
    width: 28px;
    height: 1px;
    background: var(--vm-border);
    margin: 4px auto;
}

.vm-sidebar-bottom {
    margin-top: auto;
    padding-bottom: 8px;
}

/* =============================================
   3. EXPLORER PANEL
   ============================================= */

.vm-explorer {
    grid-area: explorer;
    display: flex;
    flex-direction: column;
    background: var(--vm-bg-panel);
    border-right: 1px solid var(--vm-border);
    overflow: hidden;
}

.vm-explorer-header {
    display: flex;
    align-items: center;
    height: 44px;
    padding: 0 4px 0 0;
    font-size: 11px;
    font-weight: 600;
    letter-spacing: 0.3px;
    color: var(--vm-text-secondary);
    border-bottom: 1px solid var(--vm-border);
    background: var(--vm-bg-tertiary);
    flex-shrink: 0;
}

.vm-explorer-tabs {
    display: flex;
    flex: 1;
    height: 100%;
    align-items: center;
    gap: 2px;
}

.vm-explorer-tab {
    width: 100%;
    background: var(--vm-bg-tertiary, var(--vm-bg-secondary));
    border: 1px solid var(--vm-border);
    border-radius: 6px;
    color: var(--vm-text-secondary);
    cursor: pointer;
    padding: 4px 14px;
    margin: 3px 2px;
    font-size: 11px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.3px;
    transition: background 0.15s, color 0.15s, border-color 0.15s, box-shadow 0.15s;
}

    .vm-explorer-tab:hover {
        color: var(--vm-text-primary);
        background: var(--vm-bg-hover);
        border-color: var(--vm-accent);
    }

    .vm-explorer-tab.active {
        color: #fff;
        background: var(--vm-accent);
        border-color: var(--vm-accent);
        box-shadow: 0 1px 4px rgba(47, 107, 255, 0.3);
    }

.vm-explorer-actions {
    display: flex;
    align-items: center;
    gap: 2px;
}

    .vm-explorer-actions button {
        background: none;
        border: none;
        color: var(--vm-text-muted);
        cursor: pointer;
        padding: 2px;
        font-size: 14px;
    }

        .vm-explorer-actions button:hover {
            color: var(--vm-text-primary);
        }

.vm-explorer-header .explorer-title {
    flex: 1;
}

.vm-explorer-header button {
    background: none;
    border: none;
    color: var(--vm-text-muted);
    cursor: pointer;
    padding: 2px;
    font-size: 14px;
}

    .vm-explorer-header button:hover {
        color: var(--vm-text-primary);
    }

.vm-explorer-filter {
    display: flex;
    padding: 4px 8px;
    border-bottom: 1px solid var(--vm-border-light);
    flex-shrink: 0;
    height: 32px;
}

    .vm-explorer-filter input {
        width: 100%;
        background: var(--vm-bg-input);
        border: 1px solid var(--vm-border);
        border-radius: 3px;
        padding: 3px 6px;
        font-size: 11px;
        color: var(--vm-text-primary);
        outline: none;
    }

        .vm-explorer-filter input::placeholder {
            color: var(--vm-text-muted);
        }

        .vm-explorer-filter input:focus {
            border-color: var(--vm-border-focus);
            box-shadow: 0 0 0 2px rgba(47, 107, 255, 0.1);
        }

.vm-autocomplete-wrapper {
    position: relative;
    width: 100%;
}

    .vm-autocomplete-wrapper input {
        width: 100%;
        background: var(--vm-bg-input);
        border: 1px solid var(--vm-border);
        border-radius: 3px;
        padding: 3px 6px;
        font-size: 11px;
        color: var(--vm-text-primary);
        outline: none;
    }

        .vm-autocomplete-wrapper input:focus {
            border-color: var(--vm-border-focus);
            box-shadow: 0 0 0 2px rgba(47, 107, 255, 0.1);
        }

.vm-autocomplete-dropdown {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    z-index: 1000;
    background: var(--vm-bg-secondary);
    border: 1px solid var(--vm-border);
    border-radius: 4px;
    margin-top: 2px;
    max-height: 200px;
    overflow-y: auto;
    list-style: none;
    padding: 2px 0;
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}

    .vm-autocomplete-dropdown li {
        padding: 4px 8px;
        font-size: 11px;
        color: var(--vm-text-primary);
        cursor: pointer;
        white-space: nowrap;
        overflow: hidden;
        text-overflow: ellipsis;
    }

        .vm-autocomplete-dropdown li:hover,
        .vm-autocomplete-dropdown li.active {
            background: var(--vm-bg-hover);
            color: var(--vm-text-bright);
        }

.vm-explorer-tree {
    flex: 1;
    overflow-y: auto;
    overflow-x: hidden;
    padding: 2px 0;
}

/* Tree Nodes */
.vm-tree-node {
    display: flex;
    align-items: center;
    height: var(--vm-row-height);
    padding: 0 8px;
    cursor: pointer;
    white-space: nowrap;
    font-size: 12px;
    color: var(--vm-text-primary);
}

    .vm-tree-node:hover {
        background: var(--vm-bg-hover);
    }

    .vm-tree-node.selected {
        background: var(--vm-bg-selected);
        color: var(--vm-text-primary);
    }

    .vm-tree-node.focused {
        outline: 1px solid var(--vm-border-focus);
        outline-offset: -1px;
    }

.vm-tree-explorer {
    display: flex;
    flex-direction: column;
    height: 100%;
    overflow: hidden;
}

    .vm-tree-explorer:focus {
        outline: none;
    }

.vm-tree-node .node-indent {
    flex-shrink: 0;
}

.vm-tree-node .node-toggle {
    width: 16px;
    height: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    color: var(--vm-text-muted);
    font-size: 10px;
}

.vm-tree-node .node-icon {
    width: 16px;
    height: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    margin-right: 4px;
    font-size: 11px;
}

.vm-tree-node .node-label {
    flex: 1;
    overflow: hidden;
    text-overflow: ellipsis;
}

.vm-tree-node .node-badge {
    font-size: 9px;
    padding: 1px 4px;
    border-radius: 3px;
    margin-left: 4px;
    flex-shrink: 0;
}

.node-badge.variant {
    background: rgba(47, 107, 255, 0.1);
    color: var(--vm-variant-color);
}

.node-badge.option {
    background: rgba(76, 149, 108, 0.1);
    color: var(--vm-option-color);
}

.node-badge.exclude {
    background: rgba(192, 86, 86, 0.1);
    color: var(--vm-exclude-color);
}

.node-badge.mandatory {
    background: rgba(53, 92, 125, 0.1);
    color: var(--vm-mandatory-color);
}

.node-badge.eliminate {
    background: rgba(155, 44, 44, 0.1);
    color: var(--vm-eliminate-color);
}

.node-badge.default {
    background: rgba(113, 128, 150, 0.1);
    color: var(--vm-default-color);
}

/* === FEATURE TREE NODE TYPES === */

.tree-node {
    display: flex;
    align-items: center;
    gap: 4px;
    padding: 2px 6px;
    font-size: 12px;
    cursor: pointer;
    white-space: nowrap;
    border-radius: 2px;
}

    .tree-node:hover {
        background: var(--vm-bg-hover);
    }

    .tree-node.ft-variant .tree-node-icon {
        color: var(--vm-variant-color);
    }

    .tree-node.ft-option .tree-node-icon {
        color: var(--vm-option-color);
    }

    .tree-node.ft-root .tree-node-icon {
        color: var(--vm-text-primary);
    }

    .tree-node.ft-mandatory .tree-node-icon {
        color: var(--vm-mandatory-color);
    }

    .tree-node.ft-eliminated .tree-node-icon {
        color: var(--vm-eliminate-color);
        opacity: 0.6;
    }

    .tree-node.ft-ifthen .tree-node-icon {
        color: var(--vm-ifthen-color);
    }

    .tree-node.has-exclude {
        border-left: 2px solid var(--vm-exclude-color);
    }

    .tree-node.has-mandatory {
        border-left: 2px solid var(--vm-mandatory-color);
    }

    .tree-node.is-eliminated {
        opacity: 0.5;
    }

        .tree-node.is-eliminated .tree-node-name {
            text-decoration: line-through;
        }

.tree-node-badge {
    font-size: 9px;
    font-weight: 700;
    padding: 0 3px;
    border-radius: 2px;
    letter-spacing: 0.3px;
    line-height: 14px;
}

.badge-variant {
    background: rgba(47, 107, 255, 0.1);
    color: var(--vm-variant-color);
}

.badge-option {
    background: rgba(76, 149, 108, 0.1);
    color: var(--vm-option-color);
}

.badge-root {
    background: var(--vm-overlay-light);
    color: var(--vm-text-primary);
}

.badge-mandatory {
    background: rgba(53, 92, 125, 0.1);
    color: var(--vm-mandatory-color);
}

.badge-eliminated {
    background: rgba(155, 44, 44, 0.08);
    color: var(--vm-eliminate-color);
}

.badge-ifthen {
    background: rgba(60, 145, 179, 0.1);
    color: var(--vm-ifthen-color);
}

.badge-default {
    display: none;
}

.tree-node-icon {
    font-size: 11px;
    flex-shrink: 0;
}

.tree-node-name {
    color: var(--vm-text-primary);
    flex: 1;
    overflow: hidden;
    text-overflow: ellipsis;
}

    .tree-node-name.eliminated-text {
        text-decoration: line-through;
        color: var(--vm-text-muted);
    }

    .tree-node-name.filter-match {
        background: rgba(198, 144, 38, 0.2);
        border-radius: 2px;
        padding: 0 2px;
    }

.tree-node-class {
    font-size: 9px;
    color: var(--vm-text-muted);
    opacity: 0.7;
}

.tree-node-count {
    font-size: 9px;
    color: var(--vm-text-secondary);
    background: var(--vm-overlay-subtle);
    padding: 0 3px;
    border-radius: 8px;
}

.tree-node-rel {
    font-size: 9px;
    width: 14px;
    height: 14px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border-radius: 2px;
    flex-shrink: 0;
}

    .tree-node-rel.rel-exclude {
        background: rgba(192, 86, 86, 0.1);
        color: var(--vm-exclude-color);
    }

    .tree-node-rel.rel-mandatory {
        background: rgba(53, 92, 125, 0.1);
        color: var(--vm-mandatory-color);
    }

    .tree-node-rel.rel-ifthen {
        background: rgba(60, 145, 179, 0.1);
        color: var(--vm-ifthen-color);
    }

    .tree-node-rel.rel-eliminate {
        background: rgba(155, 44, 44, 0.1);
        color: var(--vm-eliminate-color);
    }

.tree-toggle {
    background: none;
    border: none;
    cursor: pointer;
    padding: 0;
    color: var(--vm-text-muted);
    display: flex;
    align-items: center;
}

    .tree-toggle:hover {
        color: var(--vm-text-primary);
    }

.toggle-icon {
    transition: transform 0.1s;
}

li:not(.collapsed) > .tree-node .toggle-icon {
    transform: rotate(90deg);
}

/* Tree structure */
.h-tree {
    font-size: 12px;
    list-style: none;
    padding-left: 0;
    margin: 0;
}

    .h-tree ul {
        list-style: none;
        padding-left: 16px;
        margin: 0;
    }

    .h-tree li {
        margin: 0;
    }

        .h-tree li.collapsed > ul {
            display: none;
        }

/* =============================================
   4. MAIN CONTENT AREA
   ============================================= */

.vm-main {
    grid-area: main;
    display: flex;
    flex-direction: column;
    background: var(--vm-bg-primary);
    overflow: hidden;
}

.vm-main-tabs {
    display: flex;
    align-items: center;
    height: 32px;
    background: var(--vm-bg-secondary);
    border-bottom: 1px solid var(--vm-border);
    padding: 0 4px;
    gap: 0;
    flex-shrink: 0;
    overflow-x: auto;
}

.vm-main-tab {
    display: flex;
    align-items: center;
    gap: 4px;
    height: 32px;
    padding: 0 12px;
    border: none;
    background: transparent;
    color: var(--vm-text-secondary);
    font-size: 11px;
    cursor: pointer;
    white-space: nowrap;
    border-bottom: 2px solid transparent;
    border-top: 2px solid transparent;
    font-family: var(--vm-font-ui);
}

/* Module level navigation (Home / Portfolio / References / Modularization).
   Rendered as anchors, so the default link styling has to be reset. */
.vm-module-nav {
    height: 34px;
}

    .vm-module-nav .vm-main-tab {
        height: 34px;
        text-decoration: none;
        font-weight: 500;
    }

/* Module rail inside the left sidebar. The items are anchors, therefore
   the link defaults (underline / visited colour) must be neutralised and
   the flex sizing pinned so they match the button based view icons. */
.vm-module-rail {
    flex-shrink: 0;
}

    .vm-module-rail .vm-sidebar-icon {
        text-decoration: none;
        flex-shrink: 0;
        box-sizing: border-box;
    }

        .vm-module-rail .vm-sidebar-icon:visited,
        .vm-module-rail .vm-sidebar-icon:link {
            color: var(--vm-text-muted);
        }

        .vm-module-rail .vm-sidebar-icon:hover {
            color: var(--vm-text-primary);
        }

        .vm-module-rail .vm-sidebar-icon.active,
        .vm-module-rail .vm-sidebar-icon.active:link,
        .vm-module-rail .vm-sidebar-icon.active:visited {
            color: var(--vm-accent);
        }

    .vm-main-tab:hover {
        color: var(--vm-text-primary);
        background: var(--vm-bg-hover);
    }

    .vm-main-tab.active {
        color: var(--vm-text-bright);
        border-bottom-color: var(--vm-accent);
        background: var(--vm-bg-primary);
    }

    .vm-main-tab .tab-badge {
        font-size: 9px;
        background: var(--vm-overlay-medium);
        padding: 1px 5px;
        border-radius: 8px;
        color: var(--vm-text-muted);
    }

    .vm-main-tab.active .tab-badge {
        background: rgba(47, 107, 255, 0.1);
        color: var(--vm-accent);
    }

.vm-main-content {
    flex: 1;
    overflow: auto;
    padding: 0;
    display: flex;
    flex-direction: column;
}

/* Toolbar inside main content */
.vm-toolbar {
    display: flex;
    align-items: center;
    height: 28px;
    padding: 0 8px;
    gap: 4px;
    border-bottom: 1px solid var(--vm-border-light);
    background: var(--vm-bg-tertiary);
    flex-shrink: 0;
}

.vm-toolbar-label {
    font-size: 11px;
    color: var(--vm-text-secondary);
    font-weight: 500;
}

.vm-toolbar-sep {
    width: 1px;
    height: 16px;
    background: var(--vm-border);
    margin: 0 4px;
}

.vm-toolbar-btn {
    display: flex;
    align-items: center;
    gap: 3px;
    height: 22px;
    padding: 0 6px;
    border: 1px solid var(--vm-border);
    background: var(--vm-bg-secondary);
    color: var(--vm-text-secondary);
    border-radius: 3px;
    cursor: pointer;
    font-size: 11px;
    font-family: var(--vm-font-ui);
}

    .vm-toolbar-btn:hover {
        background: var(--vm-bg-hover);
        color: var(--vm-text-primary);
        border-color: var(--vm-border-strong);
    }

    .vm-toolbar-btn.primary {
        background: var(--vm-accent);
        border-color: var(--vm-accent);
        color: #fff;
    }

        .vm-toolbar-btn.primary:hover {
            background: var(--vm-accent-hover);
        }

/* =============================================
   5. RIGHT DETAILS PANEL
   ============================================= */

.vm-details {
    grid-area: details;
    display: flex;
    flex-direction: column;
    background: var(--vm-bg-tertiary);
    border-left: 1px solid var(--vm-border);
    overflow: hidden;
}

.vm-details-header {
    display: flex;
    align-items: center;
    height: 28px;
    padding: 0 10px;
    font-size: 11px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--vm-text-secondary);
    border-bottom: 1px solid var(--vm-border);
    background: var(--vm-bg-tertiary);
    flex-shrink: 0;
}

.vm-details-content {
    flex: 1;
    overflow-y: auto;
    padding: 8px;
}

.vm-details-section {
    margin-bottom: 12px;
}

.vm-details-section-title {
    font-size: 10px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--vm-text-muted);
    margin-bottom: 4px;
    padding: 4px 2px;
    border-bottom: 1px solid var(--vm-border-light);
}

.vm-details-row {
    display: flex;
    align-items: baseline;
    padding: 2px 0;
    font-size: 11px;
    gap: 6px;
}

    .vm-details-row .detail-key {
        color: var(--vm-text-secondary);
        flex-shrink: 0;
        min-width: 80px;
    }

    .vm-details-row .detail-value {
        color: var(--vm-text-primary);
        word-break: break-word;
    }

/* =============================================
   ENGINEERING TABLES
   ============================================= */

.vm-table-wrap {
    overflow: auto;
    flex: 1;
    border-radius: 6px;
    border: 1px solid var(--vm-border);
}

.vm-table {
    width: 100%;
    /*border-collapse: collapse;*/
    font-size: 12px;
}

/* Resizable columns */
.vm-resizable-table {
    table-layout: fixed;
}

    .vm-resizable-table th {
        overflow: hidden;
        text-overflow: ellipsis;
        resize: horizontal;
    }

    .vm-resizable-table td {
        overflow: hidden;
        text-overflow: ellipsis;
    }

.vm-table thead {
    position: sticky;
    top: 0;
    z-index: 10;
}

.vm-table th {
    background: var(--vm-bg-hover);
    color: var(--vm-text-primary);
    font-weight: 600;
    font-size: 11px;
    letter-spacing: 0.3px;
    padding: 6px 10px;
    text-align: left;
    border-bottom: 2px solid var(--vm-border);
    white-space: nowrap;
    height: 30px;
    user-select: none;
    cursor: default;
    text-transform: uppercase;
}

    .vm-table th.sortable {
        cursor: pointer;
        transition: background 0.1s ease;
    }

        .vm-table th.sortable:hover {
            background: var(--vm-bg-active);
            color: var(--vm-accent);
        }

    .vm-table th.numeric {
        text-align: left;
        padding-right: 10px;
    }

.vm-table td {
    padding: 3px 10px;
    border-bottom: 1px solid var(--vm-border-light);
    height: var(--vm-row-height);
    vertical-align: middle;
    color: var(--vm-text-primary);
    transition: background 0.08s ease;
}

/* The background must be set on the cells: row backgrounds are covered by the
   td backgrounds (zebra striping, hover, sticky columns). */
.vm-table tbody tr.Highlight_Orange td {
    background-color: #FFB500 !important;
}

.vm-table tbody tr.Highlight_Orange:hover td {
    background-color: #FFD400 !important;
}

.vm-table tr:hover td {
    background: var(--vm-bg-hover);
}

.vm-table tr.selected td {
    background: var(--vm-bg-selected);
    color: var(--vm-text-primary);
}

.vm-table tr.focused td {
    outline: 1px solid var(--vm-border-focus);
    outline-offset: -1px;
}

.vm-table tr.is-eliminated td {
    opacity: 0.5;
}

.vm-table tr.row-warn td {
    border-left: 2px solid var(--vm-warning);
}

.vm-table tbody tr:nth-child(even) td {
    background: var(--vm-bg-tertiary);
}

.vm-table tbody tr:hover td {
    background: var(--vm-row-hover);
}

.vm-table tbody tr.selected:hover td {
    background: var(--vm-bg-selected);
}

.vm-mono {
    font-family: var(--vm-font-mono);
}

.vm-feature-table {
    display: flex;
    flex-direction: column;
    flex: 1;
    overflow: hidden;
}

    .vm-feature-table:focus {
        outline: none;
    }

.vm-table td.numeric {
    text-align: left;
    font-family: var(--vm-font-mono);
    font-size: 11px;
    padding-right: 10px;
}

.vm-table td.center {
    text-align: center;
}

.vm-table td.idx {
    color: var(--vm-text-muted);
    font-family: var(--vm-font-mono);
    font-size: 10px;
    width: 36px;
    text-align: center;
}

/* Editable cell */
.vm-table td.editable {
    cursor: text;
    position: relative;
}

    .vm-table td.editable:hover {
        outline: 1px solid var(--vm-border-focus);
        outline-offset: -1px;
    }

    .vm-table td.editable input {
        position: absolute;
        inset: 0;
        border: none;
        background: var(--vm-bg-input);
        color: var(--vm-text-primary);
        padding: 0 10px;
        font-size: inherit;
        font-family: inherit;
        outline: 2px solid var(--vm-accent);
        text-align: left;
    }

/* =============================================
   COST SUB-COLUMNS (Solution Input Table)
   ============================================= */

.vm-cost-group-header {
    text-align: center !important;
    position: relative;
    border-left: 2px solid var(--vm-accent);
    background: linear-gradient(180deg, var(--vm-bg-hover) 0%, var(--vm-bg-secondary) 100%);
    padding: 6px 10px !important;
    letter-spacing: 0.3px;
}

    .vm-cost-group-header .sortable {
        cursor: pointer;
        font-weight: 700;
        font-size: 12px;
        text-transform: uppercase;
        letter-spacing: 0.5px;
    }

        .vm-cost-group-header .sortable:hover {
            color: var(--vm-accent);
        }

.vm-col-add-btn,
.vm-col-filter-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 20px;
    height: 20px;
    border: 1px solid var(--vm-border);
    border-radius: 3px;
    background: var(--vm-bg-secondary);
    color: var(--vm-text-secondary);
    font-size: 12px;
    font-weight: 700;
    cursor: pointer;
    margin-left: 6px;
    vertical-align: middle;
    padding: 0;
    line-height: 1;
    transition: all 0.15s ease;
}

    .vm-col-add-btn:hover {
        background: var(--vm-accent);
        color: #fff;
        border-color: var(--vm-accent);
        transform: scale(1.1);
    }

    .vm-col-filter-btn:hover {
        background: var(--vm-bg-active);
        color: var(--vm-accent);
        border-color: var(--vm-accent);
    }

.vm-col-filter-dropdown {
    position: absolute;
    top: calc(100% + 4px);
    right: 4px;
    z-index: 100;
    background: var(--vm-bg-panel);
    border: 1px solid var(--vm-border);
    border-radius: 6px;
    box-shadow: 0 6px 20px var(--vm-shadow-color);
    padding: 8px 10px;
    min-width: 160px;
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.vm-col-filter-item {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 11px;
    font-weight: 400;
    color: var(--vm-text-primary);
    cursor: pointer;
    padding: 3px 4px;
    border-radius: 3px;
    white-space: nowrap;
    transition: background 0.1s ease;
}

    .vm-col-filter-item:hover {
        background: var(--vm-bg-hover);
    }

    .vm-col-filter-item input[type="checkbox"] {
        width: 14px;
        height: 14px;
        cursor: pointer;
        accent-color: var(--vm-accent);
    }

.vm-subcol-header {
    font-size: 10px !important;
    font-weight: 600 !important;
    padding: 3px 6px !important;
    white-space: nowrap;
    position: relative;
    border-left: 1px solid var(--vm-border-light);
    background: var(--vm-bg-hover);
    text-align: left !important;
}

    .vm-subcol-header:first-of-type {
        border-left: 2px solid var(--vm-accent);
    }

.vm-subcol-name {
    cursor: pointer;
    font-size: 10px;
    color: var(--vm-text-secondary);
    padding: 1px 2px;
    border-radius: 2px;
    transition: all 0.1s ease;
}

    .vm-subcol-name:hover {
        color: var(--vm-accent);
        background: var(--vm-bg-active);
    }

.vm-subcol-name-input {
    width: 90px;
    font-size: 10px;
    padding: 2px 4px;
    border: 1px solid var(--vm-accent);
    border-radius: 3px;
    background: var(--vm-bg-input);
    color: var(--vm-text-primary);
    outline: none;
    box-shadow: 0 0 0 2px rgba(47, 107, 255, 0.15);
}

.vm-col-remove-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 15px;
    height: 15px;
    border: none;
    border-radius: 3px;
    background: transparent;
    color: var(--vm-text-muted);
    font-size: 11px;
    font-weight: 700;
    cursor: pointer;
    margin-left: 3px;
    padding: 0;
    vertical-align: middle;
    opacity: 0;
    transition: all 0.15s ease;
}

.vm-subcol-header:hover .vm-col-remove-btn {
    opacity: 0.6;
}

.vm-col-remove-btn:hover {
    background: var(--vm-danger);
    color: #fff;
    opacity: 1 !important;
    transform: scale(1.1);
}

.vm-sum-header {
    font-weight: 700 !important;
    font-size: 12px !important;
    border-left: 2px solid var(--vm-border-strong);
    background: linear-gradient(180deg, var(--vm-bg-hover) 0%, var(--vm-bg-secondary) 100%);
    text-align: left !important;
    padding: 3px 8px !important;
    color: var(--vm-text-primary);
}

.vm-sum-cell {
    font-weight: 700;
    font-family: var(--vm-font-mono);
    font-size: 11px;
    border-left: 2px solid var(--vm-border-strong);
    background: var(--vm-overlay-subtle);
    text-align: left !important;
    padding-left: 8px !important;
    color: var(--vm-text-primary);
}

.vm-subcol-cell {
    font-size: 11px;
    border-left: 1px solid var(--vm-border-light);
    text-align: left !important;
    padding: 0 !important;
    position: relative;
    cursor: text;
    min-height: var(--vm-row-height);
}

    .vm-subcol-cell span {
        display: block;
        padding: 2px 6px;
        min-height: var(--vm-row-height);
        line-height: var(--vm-row-height);
        font-family: var(--vm-font-mono);
    }

    .vm-subcol-cell:hover {
        background: var(--vm-bg-hover);
        outline: 1px solid var(--vm-border-focus);
        outline-offset: -1px;
    }

    .vm-subcol-cell input[type="number"] {
        position: absolute;
        inset: 0;
        width: 100%;
        height: 100%;
        background: var(--vm-bg-input);
        border: none;
        color: var(--vm-text-primary);
        padding: 0 6px;
        font-size: 11px;
        font-family: var(--vm-font-mono);
        text-align: left;
        outline: 2px solid var(--vm-border-focus);
        box-sizing: border-box;
    }

        .vm-subcol-cell input[type="number"]:focus {
            background: var(--vm-bg-input);
            outline: 2px solid var(--vm-accent);
        }

/* =============================================
   KPI / STATS STRIP
   ============================================= */

.vm-stats-strip {
    display: flex;
    gap: 1px;
    background: var(--vm-border);
    border-bottom: 1px solid var(--vm-border);
    flex-shrink: 0;
}

.vm-stat {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 6px 16px;
    background: var(--vm-bg-secondary);
    min-width: 100px;
}

.vm-stat-value {
    font-size: 16px;
    font-weight: 600;
    font-family: var(--vm-font-mono);
    color: var(--vm-text-primary);
}

.vm-stat-label {
    font-size: 9px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--vm-text-muted);
    margin-top: 1px;
}

.vm-stat.warn .vm-stat-value {
    color: var(--vm-warning);
}

.vm-stat.danger .vm-stat-value {
    color: var(--vm-danger);
}

.vm-stat.success .vm-stat-value {
    color: var(--vm-success);
}

.vm-stat.info .vm-stat-value {
    color: var(--vm-info);
}

/* =============================================
   DEPENDENCY BADGES & INDICATORS
   ============================================= */

.vm-badge {
    display: inline-flex;
    align-items: center;
    font-size: 9px;
    font-weight: 600;
    padding: 1px 5px;
    border-radius: 2px;
    letter-spacing: 0.3px;
}

    .vm-badge.xor {
        background: rgba(47, 107, 255, 0.1);
        color: var(--vm-variant-color);
    }

    .vm-badge.or {
        background: rgba(76, 149, 108, 0.1);
        color: var(--vm-option-color);
    }

    .vm-badge.excl {
        background: rgba(192, 86, 86, 0.1);
        color: var(--vm-exclude-color);
    }

    .vm-badge.mand {
        background: rgba(53, 92, 125, 0.1);
        color: var(--vm-mandatory-color);
    }

    .vm-badge.high {
        background: rgba(192, 86, 86, 0.1);
        color: var(--vm-danger);
    }

    .vm-badge.medium {
        background: rgba(198, 144, 38, 0.1);
        color: var(--vm-warning);
    }

    .vm-badge.low {
        background: rgba(76, 149, 108, 0.1);
        color: var(--vm-success);
    }

/* =============================================
   DEPENDENCY MATRIX
   ============================================= */

.vm-matrix {
    border-collapse: collapse;
    font-size: 10px;
}

    .vm-matrix th {
        background: var(--vm-bg-hover);
        padding: 2px 4px;
        font-weight: 500;
        font-size: 10px;
        max-width: 80px;
        overflow: hidden;
        text-overflow: ellipsis;
        color: var(--vm-text-primary);
    }

        .vm-matrix th.row-header {
            text-align: left;
            position: sticky;
            left: 0;
            z-index: 5;
            background: var(--vm-bg-hover);
        }

    .vm-matrix td {
        width: 24px;
        height: 24px;
        text-align: center;
        border: 1px solid var(--vm-border-light);
        cursor: pointer;
        padding: 0;
        color: var(--vm-text-primary);
    }

        .vm-matrix td:hover {
            outline: 2px solid var(--vm-border-focus);
            outline-offset: -2px;
        }

        /* Dependency Matrix cell colors per spec */
        .vm-matrix td.cell-mandatory {
            background: var(--vm-matrix-mandatory);
        }

        .vm-matrix td.cell-exclude {
            background: var(--vm-matrix-exclude);
        }

        .vm-matrix td.cell-ifthen {
            background: var(--vm-matrix-ifthen);
        }

        .vm-matrix td.cell-eliminate {
            background: var(--vm-matrix-eliminate);
        }

        .vm-matrix td.cell-self {
            background: var(--vm-bg-hover);
            cursor: default;
        }

/* Matrix container & enhancements */
.vm-matrix-container {
    display: flex;
    flex-direction: column;
    flex: 1;
    overflow: hidden;
}

    .vm-matrix-container:focus {
        outline: none;
    }

.vm-matrix-scroll {
    flex: 1;
    overflow: auto;
}

.vm-matrix td.highlight {
    background: var(--vm-matrix-highlight);
}

.vm-matrix td.cell-focused {
    outline: 2px solid var(--vm-border-focus);
    outline-offset: -2px;
}

.vm-matrix th.hovered {
    background: var(--vm-bg-active);
}

.vm-matrix tr.hovered > th {
    background: var(--vm-bg-active);
}

.vm-matrix .matrix-col-label {
    display: inline-block;
    writing-mode: vertical-lr;
    transform: rotate(180deg);
    font-size: 9px;
    max-height: 60px;
    overflow: hidden;
}

/* Matrix legend */
.matrix-legend {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 10px;
    color: var(--vm-text-muted);
}

.legend-cell {
    display: inline-block;
    width: 12px;
    height: 12px;
    border-radius: 2px;
    vertical-align: middle;
    margin-right: 2px;
}

    .legend-cell.cell-exclude {
        background: var(--vm-matrix-exclude);
    }

    .legend-cell.cell-mandatory {
        background: var(--vm-matrix-mandatory);
    }

    .legend-cell.cell-ifthen {
        background: var(--vm-matrix-ifthen);
    }

    .legend-cell.cell-eliminate {
        background: var(--vm-matrix-eliminate);
    }

/* Matrix cell type picker popup */
.matrix-picker {
    background: var(--vm-bg-secondary);
    border: 1px solid var(--vm-border);
    border-radius: 4px;
    padding: 8px;
    box-shadow: 0 2px 8px var(--vm-shadow-color);
    z-index: 1001;
    min-width: 160px;
}

.matrix-picker-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 1000;
    background: transparent;
}

.matrix-picker-title {
    font-size: 10px;
    font-weight: 600;
    color: var(--vm-text-secondary);
    text-transform: uppercase;
    margin-bottom: 6px;
}

.matrix-picker-btn {
    display: block;
    width: 100%;
    text-align: left;
    padding: 4px 8px;
    border: none;
    background: transparent;
    color: var(--vm-text-primary);
    font-size: 11px;
    border-radius: 3px;
    cursor: pointer;
    font-family: var(--vm-font-ui);
}

    .matrix-picker-btn:hover {
        background: var(--vm-bg-hover);
    }

    .matrix-picker-btn.picker-exclude:hover {
        background: var(--vm-matrix-exclude);
    }

    .matrix-picker-btn.picker-mandatory:hover {
        background: var(--vm-matrix-mandatory);
    }

    .matrix-picker-btn.picker-ifthen:hover {
        background: var(--vm-matrix-ifthen);
    }

    .matrix-picker-btn.picker-eliminate:hover {
        background: var(--vm-matrix-eliminate);
    }

    .matrix-picker-btn.picker-clear {
        color: var(--vm-danger);
    }

.matrix-picker-sep {
    height: 1px;
    background: var(--vm-border);
    margin: 4px 0;
}

/* === RULE EDITOR === */
.vm-rule-editor {
    display: flex;
    flex-direction: column;
    gap: 8px;
    padding: 8px;
    background: var(--vm-bg-secondary);
    border: 1px solid var(--vm-border);
    border-radius: 4px;
}

.rule-editor-header {
    display: flex;
    align-items: center;
    gap: 4px;
}

.rule-visual {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.rule-section {
    display: flex;
    align-items: center;
    gap: 8px;
}

.rule-section-label {
    font-size: 10px;
    font-weight: 700;
    color: var(--vm-text-muted);
    text-transform: uppercase;
    min-width: 40px;
}

.rule-conditions {
    display: flex;
    align-items: center;
    gap: 4px;
    flex-wrap: wrap;
}

.rule-arrow {
    font-size: 16px;
    color: var(--vm-text-muted);
    text-align: center;
    padding: 2px 0;
}

.rule-chip {
    display: inline-flex;
    align-items: center;
    gap: 3px;
    padding: 2px 8px;
    background: var(--vm-bg-tertiary);
    border: 1px solid var(--vm-border);
    border-radius: 3px;
    font-size: 11px;
    color: var(--vm-text-primary);
    cursor: pointer;
}

    .rule-chip:hover {
        border-color: var(--vm-border-focus);
    }

    .rule-chip.highlighted {
        border-color: var(--vm-accent);
        background: rgba(47, 107, 255, 0.06);
    }

    .rule-chip.consequence {
        border-color: var(--vm-warning);
        background: rgba(198, 144, 38, 0.06);
    }

.rule-chip-remove {
    background: none;
    border: none;
    color: var(--vm-text-muted);
    cursor: pointer;
    font-size: 10px;
    padding: 0 2px;
}

    .rule-chip-remove:hover {
        color: var(--vm-danger);
    }

.rule-operator {
    font-size: 12px;
    font-weight: 700;
    color: var(--vm-text-muted);
}

.rule-add-btn {
    background: none;
    border: 1px dashed var(--vm-border);
    color: var(--vm-text-muted);
    padding: 2px 8px;
    border-radius: 3px;
    font-size: 11px;
    cursor: pointer;
}

    .rule-add-btn:hover {
        border-color: var(--vm-accent);
        color: var(--vm-accent);
    }

.rule-type-btns {
    display: flex;
    gap: 4px;
}

.rule-text-mode {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.rule-text-input {
    width: 100%;
    background: var(--vm-bg-input);
    border: 1px solid var(--vm-border);
    border-radius: 3px;
    color: var(--vm-text-primary);
    font-family: var(--vm-font-mono);
    font-size: 11px;
    padding: 6px 8px;
    resize: vertical;
}

    .rule-text-input:focus {
        border-color: var(--vm-border-focus);
        outline: none;
        box-shadow: 0 0 0 2px rgba(47, 107, 255, 0.1);
    }

.rule-text-help {
    font-size: 10px;
    color: var(--vm-text-muted);
}

.rule-node-picker {
    border: 1px solid var(--vm-border);
    border-radius: 3px;
    background: var(--vm-bg-panel);
    max-height: 200px;
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

.rule-picker-filter {
    padding: 4px 8px;
    border: none;
    border-bottom: 1px solid var(--vm-border);
    background: var(--vm-bg-tertiary);
    color: var(--vm-text-primary);
    font-size: 11px;
    outline: none;
}

.rule-picker-list {
    flex: 1;
    overflow-y: auto;
}

.rule-picker-item {
    padding: 3px 8px;
    font-size: 11px;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 4px;
}

    .rule-picker-item:hover {
        background: var(--vm-bg-hover);
    }

/* =============================================
   EMPTY / LOADING / STATUS
   ============================================= */

.vm-empty {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 40px 20px;
    color: var(--vm-text-muted);
    font-size: 12px;
    text-align: center;
    gap: 8px;
}

.vm-loading {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 40px;
    gap: 8px;
    color: var(--vm-text-muted);
}

.vm-spinner {
    width: 16px;
    height: 16px;
    border: 2px solid var(--vm-border);
    border-top-color: var(--vm-accent);
    border-radius: 50%;
    animation: vm-spin 0.6s linear infinite;
}

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

/* =============================================
   SCROLLBARS (thin, engineering style)
   ============================================= */

.vm-app ::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

.vm-app ::-webkit-scrollbar-track {
    background: transparent;
}

.vm-app ::-webkit-scrollbar-thumb {
    background: var(--vm-scrollbar-thumb);
    border-radius: 4px;
}

    .vm-app ::-webkit-scrollbar-thumb:hover {
        background: var(--vm-scrollbar-thumb-hover);
    }

/* =============================================
   RESIZE HANDLES
   ============================================= */

.vm-resize-handle {
    width: 4px;
    cursor: col-resize;
    background: transparent;
    transition: background 0.2s;
}

    .vm-resize-handle:hover,
    .vm-resize-handle.dragging {
        background: var(--vm-accent);
    }

/* =============================================
   VERTICAL SPLITTER
   ============================================= */

.vm-vsplit-handle {
    height: 6px;
    cursor: row-resize;
    background: var(--vm-border);
    border-radius: 3px;
    margin: 2px 0;
    transition: background 0.2s;
    flex-shrink: 0;
}

    .vm-vsplit-handle:hover {
        background: var(--vm-accent);
    }

/* =============================================
   INFO TOOLTIP ICON
   ============================================= */

.vm-info-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 14px;
    height: 14px;
    border-radius: 50%;
    border: 1px solid var(--vm-text-muted);
    font-size: 9px;
    font-weight: 700;
    color: var(--vm-text-muted);
    cursor: help;
    position: relative;
    vertical-align: middle;
    margin-left: 3px;
}

    .vm-info-icon:hover {
        border-color: var(--vm-accent);
        color: var(--vm-accent);
    }

/* =============================================
   UTILITY
   ============================================= */

.vm-mono {
    font-family: var(--vm-font-mono);
}

.vm-muted {
    color: var(--vm-text-muted);
}

.vm-bright {
    color: var(--vm-text-bright);
}

.vm-accent {
    color: var(--vm-accent);
}

.vm-danger {
    color: var(--vm-danger);
}

.vm-success {
    color: var(--vm-success);
}

.vm-warning {
    color: var(--vm-warning);
}

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

.vm-flex {
    display: flex;
    align-items: center;
}

.vm-gap-4 {
    gap: 4px;
}

.vm-gap-8 {
    gap: 8px;
}

.vm-flex-1 {
    flex: 1;
    min-width: 0;
}

.vm-px-8 {
    padding-left: 8px;
    padding-right: 8px;
}

.vm-py-4 {
    padding-top: 4px;
    padding-bottom: 4px;
}

/* === CONFIGURATION ANALYSIS LAYOUT === */
.vm-config-layout {
    display: flex;
    gap: 0;
    flex: 1;
    min-height: 0;
    overflow: hidden;
}

.vm-config-table-area {
    flex: 1;
    min-width: 0;
    overflow: auto;
}

.vm-config-details-panel {
    width: 280px;
    min-width: 240px;
    border-left: 1px solid var(--vm-border);
    background: var(--vm-bg-tertiary);
    padding: 12px;
    overflow-y: auto;
}

/* === FEATURE ANALYSIS LAYOUT === */
.vm-feature-analysis-layout {
    display: flex;
    gap: 0;
    flex: 1;
    min-height: 0;
    overflow: hidden;
}

.vm-feature-analysis-table {
    flex: 1;
    min-width: 0;
    overflow: auto;
}

.vm-feature-analysis-details {
    width: 280px;
    min-width: 240px;
    border-left: 1px solid var(--vm-border);
    background: var(--vm-bg-tertiary);
    padding: 12px;
    overflow-y: auto;
}

/* === COMPLEX RULES PANEL === */
.vm-complex-rules {
    margin-top: 8px;
    border-top: 1px solid var(--vm-border);
    padding-top: 4px;
}

/* === TRACEABILITY VIEW === */
.vm-traceability-layout {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    gap: 0;
    height: 100%;
    overflow: hidden;
}

.vm-trace-col {
    overflow-y: auto;
    padding: 8px;
    border-right: 1px solid var(--vm-border);
}

    .vm-trace-col:last-child {
        border-right: none;
        border-left: 1px solid var(--vm-border);
    }

.vm-trace-col-header {
    font-size: 11px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--vm-text-secondary);
    padding: 4px 8px 8px;
    border-bottom: 1px solid var(--vm-border);
    margin-bottom: 4px;
}

.vm-trace-node {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 5px 8px;
    border-radius: 3px;
    cursor: pointer;
    font-size: 12px;
    color: var(--vm-text-primary);
    transition: background 0.1s;
}

    .vm-trace-node:hover {
        background: var(--vm-bg-hover);
    }

    .vm-trace-node.selected {
        background: var(--vm-selection-bg);
        color: var(--vm-selection-fg);
    }

    .vm-trace-node.highlighted {
        background: rgba(59,130,246,0.12);
        border-left: 2px solid #3b82f6;
    }

.vm-trace-icon {
    font-size: 13px;
    flex-shrink: 0;
}

.vm-trace-badge {
    margin-left: auto;
    font-size: 10px;
    background: var(--vm-bg-tertiary);
    color: var(--vm-text-secondary);
    padding: 1px 5px;
    border-radius: 8px;
    min-width: 18px;
    text-align: center;
}

.vm-trace-edges {
    min-width: 200px;
    max-width: 320px;
    padding: 8px;
    overflow-y: auto;
    background: var(--vm-bg-secondary);
}

.vm-trace-edge {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 4px 6px;
    border-radius: 3px;
    font-size: 11px;
    margin-bottom: 2px;
    border-left: 2px solid var(--vm-border);
}

    .vm-trace-edge.vm-trace-mandatory {
        border-left-color: #3b82f6;
    }

    .vm-trace-edge.vm-trace-conditional {
        border-left-color: #06b6d4;
    }

    .vm-trace-edge.vm-trace-optional {
        border-left-color: #6b9a6b;
    }

.vm-trace-arrow {
    color: var(--vm-text-secondary);
    font-size: 12px;
    flex-shrink: 0;
}

/* ── Toggle button group ── */
.vm-toggle-group {
    display: inline-flex;
    border: 1px solid var(--vm-border);
    border-radius: 4px;
    overflow: hidden;
}
.vm-toggle-btn {
    background: transparent;
    border: none;
    padding: 4px 8px;
    cursor: pointer;
    color: var(--vm-text-secondary);
    display: flex;
    align-items: center;
    transition: background 0.15s, color 0.15s;
}
.vm-toggle-btn:hover { background: var(--vm-hover); }
.vm-toggle-btn.active {
    background: var(--vm-accent);
    color: #fff;
}
.vm-toggle-btn + .vm-toggle-btn { border-left: 1px solid var(--vm-border); }

/* ── Configuration cell table ── */
.vm-config-cell-table td.vm-config-cell {
    padding: 0;
    vertical-align: top;
    min-width: 110px;
}
.vm-config-cell-table th.vm-resizable-col {
    resize: horizontal;
    overflow: hidden;
    min-width: 90px;
}
.vm-config-cell-table td.vm-config-cell .vm-cell-name {
    text-align: center;
    padding: 4px 6px 2px;
    font-weight: 600;
    font-size: 11px;
    border-bottom: 1px solid var(--vm-border);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}
.vm-config-cell-table td.vm-config-cell .vm-cell-values {
    display: flex;
    justify-content: space-between;
    padding: 2px 6px 4px;
    font-size: 10px;
    font-family: var(--vm-mono, monospace);
}
.vm-config-cell-table td.vm-config-cell .vm-cell-pct {
    color: var(--vm-text-secondary);
}
.vm-config-cell-table td.vm-config-cell .vm-cell-val {
    color: var(--vm-accent);
    font-weight: 500;
}
.vm-config-cell-table td.vm-config-cell .vm-cell-pct.editable,
.vm-config-cell-table td.vm-config-cell .vm-cell-val.editable {
    cursor: pointer;
    border-radius: 3px;
    padding: 1px 3px;
    transition: background 0.15s;
}
.vm-config-cell-table td.vm-config-cell .vm-cell-pct.editable:hover,
.vm-config-cell-table td.vm-config-cell .vm-cell-val.editable:hover {
    background: var(--vm-hover, rgba(255,255,255,0.08));
    outline: 1px solid var(--vm-border);
}
.vm-config-cell-table .vm-cell-input {
    width: 60px;
    font-size: 10px;
    font-family: var(--vm-mono, monospace);
    padding: 1px 3px;
    border: 1px solid var(--vm-accent);
    border-radius: 3px;
    background: var(--vm-bg, #1e1e2e);
    color: var(--vm-text, #cdd6f4);
    outline: none;
}

/* ── Filter highlight (red border) ── */
.vm-filter-highlight {
    outline: 2px solid #ef4444 !important;
    outline-offset: -2px;
}
.vm-filter-highlight-cell {
    box-shadow: inset 0 0 0 2px #ef4444;
}