/* ===== Theme Variables ===== */
/* Ecosystem-standard palette (Free Open Tools Style Guide §2) */
:root {
    --color-accent:        #2563EB;
    --color-accent-hover:  #1D4ED8;
    --color-accent-soft:   #2563EB1A;
    --color-success:       #16A34A;
    --color-warning:       #D97706;
    --color-danger:        #DC2626;

    --space-1: 4px;
    --space-2: 8px;
    --space-3: 12px;
    --space-4: 16px;
    --space-5: 24px;
    --space-6: 32px;
    --space-7: 48px;
    --space-8: 64px;

    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;

    --shadow-sm: 0 1px 2px rgba(0,0,0,0.06);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.10);
    --shadow-lg: 0 12px 32px rgba(0,0,0,0.16);
}

:root,
[data-theme="dark"] {
    --color-bg:            #0E0E10;
    --color-bg-subtle:     #17171A;
    --color-surface:       #1C1C20;
    --color-border:        #2C2C32;
    --color-text:          #F2F2F3;
    --color-text-muted:    #A3A3AB;
    --color-text-disabled: #5B5B63;

    --color-canvas-bg:       #1C1C20;
    --color-oob-bg:          #17171A;
    --color-input-bg:        #1C1C20;
    --color-context-bg:      #1C1C20;
    --color-icon-default:    #A3A3AB;
    --color-icon-hover:      #F2F2F3;
    --color-grid-line:       #2C2C32;
    --color-btn-active-bg:   #2C2C32;
    --color-btn-hover-bg:    #2C2C32;
    --color-btn-hover-border:#2C2C32;
    --color-handle-border:   #0E0E10;
    --color-scrollbar-track: #17171A;
    --color-scrollbar-thumb: #2C2C32;
    --color-scrollbar-thumb-hover: #45475A;
    --color-toolbar-divider: #2C2C32;
    --color-border-input:    #45475A;
}

[data-theme="light"] {
    --color-bg:            #FFFFFF;
    --color-bg-subtle:     #F5F5F7;
    --color-surface:       #FFFFFF;
    --color-border:        #E2E2E5;
    --color-text:          #111113;
    --color-text-muted:    #5B5B63;
    --color-text-disabled: #9A9AA1;

    --color-canvas-bg:       #FFFFFF;
    --color-oob-bg:          #F5F5F7;
    --color-input-bg:        #FFFFFF;
    --color-context-bg:      #FFFFFF;
    --color-icon-default:    #9A9AA1;
    --color-icon-hover:      #111113;
    --color-grid-line:       #E2E2E5;
    --color-btn-active-bg:   #E2E2E5;
    --color-btn-hover-bg:    #F5F5F7;
    --color-btn-hover-border:#E2E2E5;
    --color-handle-border:   #FFFFFF;
    --color-scrollbar-track: #F5F5F7;
    --color-scrollbar-thumb: #E2E2E5;
    --color-scrollbar-thumb-hover: #9A9AA1;
    --color-toolbar-divider: #E2E2E5;
    --color-border-input:    #E2E2E5;
}

/* ===== Reset & Base ===== */
* { margin: 0; padding: 0; box-sizing: border-box; }

html, body {
    width: 100%; height: 100%;
    overflow: hidden;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: var(--color-bg);
    color: var(--color-text);
}

/* ===== Skip to Content ===== */
.sr-only {
    position: absolute;
    width: 1px; height: 1px;
    padding: 0; margin: -1px;
    overflow: hidden;
    clip: rect(0,0,0,0);
    white-space: nowrap;
    border: 0;
}

.skip-link {
    position: absolute;
    top: -100%;
    left: 0;
    z-index: 10000;
    padding: var(--space-2) var(--space-4);
    background: var(--color-accent);
    color: #fff;
    text-decoration: none;
    font-size: 16px;
    font-weight: 600;
    border-radius: 0 0 var(--radius-sm) 0;
}
.skip-link:focus {
    top: 0;
    outline: 2px solid var(--color-accent);
    outline-offset: 2px;
}

/* ===== Global Focus States ===== */
:focus-visible {
    outline: 2px solid var(--color-accent);
    outline-offset: 2px;
}

/* ===== Reduced Motion ===== */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        transition-duration: 0.01ms !important;
    }
}

/* ===== Toolbar ===== */
#toolbar {
    position: fixed; top: 0; left: 0; right: 0;
    height: 60px;
    background: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    display: flex; align-items: center;
    padding: 0 var(--space-3);
    z-index: 1000;
    gap: var(--space-1);
    touch-action: manipulation;
    overflow-x: auto;
    overflow-y: hidden;
    -webkit-overflow-scrolling: touch;
}

.app-logo {
    font-size: 16px; font-weight: 700;
    color: var(--color-accent);
    margin-right: var(--space-2);
    user-select: none;
    letter-spacing: -0.5px;
    white-space: nowrap;
    text-decoration: none;
    cursor: pointer;
}
.app-logo:hover {
    color: var(--color-accent-hover);
}

.toolbar-divider {
    width: 1px; height: 32px;
    background: var(--color-toolbar-divider);
    margin: 0 var(--space-1);
    flex-shrink: 0;
}

.tool-btn {
    width: 44px; height: 44px;
    min-width: 44px; min-height: 44px;
    border: none;
    background: transparent;
    color: var(--color-icon-default);
    border-radius: var(--radius-sm);
    cursor: pointer;
    display: flex; align-items: center; justify-content: center;
    transition: all 0.15s;
    flex-shrink: 0;
}

.tool-btn:hover { background: var(--color-btn-hover-bg); color: var(--color-icon-hover); }
.tool-btn.active { background: var(--color-btn-active-bg); color: var(--color-accent); box-shadow: inset 0 0 0 1.5px var(--color-accent); position: relative; }
.tool-btn.active::after {
    content: '';
    position: absolute;
    bottom: 2px;
    left: 50%;
    transform: translateX(-50%);
    width: var(--space-1);
    height: var(--space-1);
    border-radius: 50%;
    background: var(--color-accent);
}
.tool-btn:active { transform: scale(0.95); }

/* Primary button variant (ecosystem primary action) */
.tool-btn-primary {
    width: 44px; height: 44px;
    min-width: 44px; min-height: 44px;
    border: none;
    background: var(--color-accent);
    color: #fff;
    border-radius: var(--radius-sm);
    cursor: pointer;
    display: flex; align-items: center; justify-content: center;
    transition: all 0.15s;
    flex-shrink: 0;
}
.tool-btn-primary:hover { background: var(--color-accent-hover); color: #fff; }
.tool-btn-primary:active { transform: scale(0.95); }

/* Shape buttons in toolbar */
.shape-btn {
    width: 44px; height: 44px;
    min-width: 44px; min-height: 44px;
    border: 1px solid transparent;
    background: transparent;
    color: var(--color-icon-default);
    border-radius: var(--radius-sm);
    cursor: pointer;
    display: flex; align-items: center; justify-content: center;
    transition: all 0.15s;
    flex-shrink: 0;
}

.shape-btn:hover { background: var(--color-btn-hover-bg); color: var(--color-icon-hover); border-color: var(--color-btn-hover-border); }
.shape-btn.active { background: var(--color-btn-active-bg); color: var(--color-accent); border-color: var(--color-accent); position: relative; }
.shape-btn.active::after {
    content: '';
    position: absolute;
    bottom: 2px;
    left: 50%;
    transform: translateX(-50%);
    width: var(--space-1);
    height: var(--space-1);
    border-radius: 50%;
    background: var(--color-accent);
}

.shape-btn svg { width: 22px; height: 18px; }

/* Style controls in toolbar */
#toolbar input[type="color"] {
    width: 44px; height: 44px;
    min-width: 44px; min-height: 44px;
    border: 2px solid var(--color-border-input);
    border-radius: var(--radius-sm);
    cursor: pointer;
    padding: 2px;
    background: none;
    flex-shrink: 0;
}
#toolbar input[type="color"]::-webkit-color-swatch-wrapper { padding: 0; }
#toolbar input[type="color"]::-webkit-color-swatch { border: none; border-radius: 2px; }

#toolbar > input[type="number"] {
    width: 48px; height: 44px;
    min-height: 44px;
    background: var(--color-input-bg);
    border: 1px solid var(--color-border-input);
    border-radius: var(--radius-sm);
    color: var(--color-text);
    font-size: 16px;
    text-align: center;
    padding: 2px;
    flex-shrink: 0;
}
#toolbar > input[type="number"]:focus { border-color: var(--color-accent); outline: none; }

#toolbar input[type="range"] {
    width: 64px; height: 44px;
    -webkit-appearance: none;
    appearance: none;
    background: transparent;
    border-radius: 2px;
    outline: none;
    flex-shrink: 0;
    cursor: pointer;
    padding: 0 var(--space-2);
}
#toolbar input[type="range"]::-webkit-slider-runnable-track {
    width: 100%;
    height: 6px;
    background: var(--color-border-input);
    border-radius: var(--radius-sm);
}
#toolbar input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 20px; height: 20px;
    background: var(--color-accent);
    border-radius: 50%;
    cursor: pointer;
    margin-top: -7px;
}
#toolbar input[type="range"]::-moz-range-track {
    height: 6px;
    background: var(--color-border-input);
    border-radius: var(--radius-sm);
}
#toolbar input[type="range"]::-moz-range-thumb {
    width: 20px; height: 20px;
    background: var(--color-accent);
    border-radius: 50%;
    border: none;
    cursor: pointer;
}

.zoom-display {
    font-size: 12px; color: var(--color-text-muted);
    padding: 0 var(--space-1);
    user-select: none;
    white-space: nowrap;
    min-width: 46px;
    text-align: center;
    font-variant-numeric: tabular-nums;
}

/* ===== Theme toggle ===== */
#theme-toggle {
    width: 44px; height: 44px;
    min-width: 44px; min-height: 44px;
    border: none;
    background: transparent;
    color: var(--color-icon-default);
    border-radius: var(--radius-sm);
    cursor: pointer;
    display: flex; align-items: center; justify-content: center;
    transition: all 0.15s;
    flex-shrink: 0;
    font-size: 18px;
}
#theme-toggle:hover { background: var(--color-btn-hover-bg); color: var(--color-icon-hover); }

/* ===== Canvas ===== */
#canvas-container {
    position: fixed; top: 60px; left: 0; right: 0; bottom: 0;
    overflow: hidden;
    background: var(--color-oob-bg);
    touch-action: none;
    -webkit-user-select: none;
    -webkit-touch-callout: none;
}

#canvas {
    position: absolute; top: 0; left: 0;
    width: 100%; height: 100%;
    transform-origin: 0 0;
}

#grid-layer {
    position: absolute; top: 0; left: 0;
    width: 10000px; height: 10000px;
    pointer-events: none;
    z-index: 0;
    background: var(--color-oob-bg);
}

#shapes-layer {
    position: absolute; top: 0; left: 0;
    width: 100%; height: 100%;
    z-index: 1;
}

#preview-layer {
    position: absolute; top: 0; left: 0;
    width: 100%; height: 100%;
    z-index: 3;
    pointer-events: none;
}

/* ===== Shapes ===== */
.diagram-shape {
    position: absolute;
    cursor: move;
    user-select: none;
    min-width: 20px; min-height: 20px;
}

.diagram-shape:hover { filter: brightness(1.05); }
.diagram-shape.selected { box-shadow: 0 0 0 2px var(--color-accent), 0 0 12px var(--color-accent-soft); }
.diagram-shape.locked { cursor: not-allowed; opacity: 0.7; }

/* Resize handles */
.resize-handle {
    position: absolute;
    width: 22px; height: 22px;
    background: var(--color-accent);
    border: 2px solid var(--color-handle-border);
    border-radius: var(--radius-sm);
    z-index: 10;
}

.resize-handle.nw { cursor: nw-resize; }
.resize-handle.ne { cursor: ne-resize; }
.resize-handle.sw { cursor: sw-resize; }
.resize-handle.se { cursor: se-resize; }
.resize-handle.n { cursor: n-resize; }
.resize-handle.s { cursor: s-resize; }
.resize-handle.w { cursor: w-resize; }
.resize-handle.e { cursor: e-resize; }
.resize-handle:hover { background: var(--color-accent-hover); transform: scale(1.3); }

/* Shape text */
.shape-text {
    position: absolute;
    pointer-events: none;
    touch-action: none;
    font-weight: 500;
    white-space: pre-wrap; word-break: break-word;
    max-width: calc(100% - var(--space-4)); max-height: calc(100% - var(--space-4));
    overflow: hidden;
    line-height: 1.3;
    padding: var(--space-1);
}
.shape-text-center       { top: 50%; left: 50%; transform: translate(-50%, -50%); text-align: center; }
.shape-text-top-left      { top: var(--space-2); left: var(--space-2); text-align: left; }
.shape-text-top-center     { top: var(--space-2); left: 50%; transform: translateX(-50%); text-align: center; }
.shape-text-top-right     { top: var(--space-2); right: var(--space-2); text-align: right; }
.shape-text-middle-left    { top: 50%; left: var(--space-2); transform: translateY(-50%); text-align: left; }
.shape-text-middle-right   { top: 50%; right: var(--space-2); transform: translateY(-50%); text-align: right; }
.shape-text-bottom-left    { bottom: var(--space-2); left: var(--space-2); text-align: left; }
.shape-text-bottom-center  { bottom: var(--space-2); left: 50%; transform: translateX(-50%); text-align: center; }
.shape-text-bottom-right   { bottom: var(--space-2); right: var(--space-2); text-align: right; }

/* ===== Connections ===== */
.conn-sel { filter: brightness(1.15); }
.conn-arrow { pointer-events: none; }

/* ===== Properties Panel ===== */
#properties-panel {
    position: fixed; top: 60px; right: 0; bottom: 0;
    width: 240px;
    background: var(--color-bg-subtle);
    border-left: 1px solid var(--color-border);
    display: flex;
    flex-direction: column;
    z-index: 900;
    transition: none;
}

/* ===== Panel Resize Handle ===== */
#panel-resize-handle {
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 8px;
    cursor: col-resize;
    z-index: 910;
    background: transparent;
    transition: background 0.15s;
}
#panel-resize-handle:hover,
#panel-resize-handle.active {
    background: var(--color-accent-soft);
}
#panel-resize-handle::after {
    content: '';
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
    width: 2px;
    height: 40px;
    border-radius: 2px;
    background: var(--color-border);
    opacity: 0;
    transition: opacity 0.15s, background 0.15s;
}
#panel-resize-handle:hover::after,
#panel-resize-handle.active::after {
    opacity: 1;
    background: var(--color-accent);
}

#properties-panel.hidden { display: none; }

#properties-panel.collapsed {
    width: 40px;
    min-width: 40px;
}
#properties-panel.collapsed .panel-scroll,
#properties-panel.collapsed .panel-layers-content,
#properties-panel.collapsed .panel-log,
#properties-panel.collapsed .panel-tabs,
#properties-panel.collapsed #panel-resize-handle { display: none; }
#properties-panel.collapsed .panel-header {
    padding: var(--space-2);
    border-bottom: none;
    cursor: pointer;
    flex: 1;
    justify-content: center;
}
#properties-panel.collapsed .panel-header .collapse-btn {
    width: 28px;
    height: 28px;
    padding: 0;
    font-size: 14px;
    background: var(--color-canvas-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    color: var(--color-accent);
}
#properties-panel.collapsed .panel-header .collapse-btn:hover {
    color: var(--color-accent-hover);
    border-color: var(--color-accent);
    background: var(--color-btn-hover-bg);
}

.panel-scroll {
    flex: 1;
    overflow-y: auto;
}

.panel-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 14px; font-weight: 600;
    color: var(--color-accent);
    padding: 0;
    border-bottom: 1px solid var(--color-border);
    flex-shrink: 0;
}
.panel-tabs {
    display: flex;
    flex: 1;
}
.panel-tab {
    flex: 1;
    padding: var(--space-2) var(--space-2);
    background: none;
    border: none;
    border-bottom: 2px solid transparent;
    color: var(--color-text-disabled);
    font-size: 12px;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    font-weight: 600;
    cursor: pointer;
    transition: color 0.15s, border-color 0.15s;
    font-family: inherit;
    min-height: 44px;
}
.panel-tab:hover {
    color: var(--color-text-muted);
}
.panel-tab.active {
    color: var(--color-accent);
    border-bottom-color: var(--color-accent);
}
.panel-header .collapse-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--color-accent-soft);
    border: 1px solid var(--color-accent);
    color: var(--color-accent);
    cursor: pointer;
    width: 32px;
    height: 32px;
    border-radius: var(--radius-sm);
    margin: var(--space-2);
    flex-shrink: 0;
    transition: all 0.15s;
}
.panel-header .collapse-btn:hover {
    background: var(--color-accent);
    color: #FFFFFF;
    border-color: var(--color-accent);
}
.panel-header .collapse-btn svg {
    width: 16px;
    height: 16px;
    display: block;
    transition: transform 0.2s;
}

.panel-section {
    border-bottom: 1px solid var(--color-border);
}
.panel-section:last-child {
    border-bottom: none;
}

/* Collapsible section toggle button */
.panel-toggle {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    width: 100%;
    background: none;
    border: none;
    padding: var(--space-4);
    cursor: pointer;
    font: inherit;
    color: inherit;
    text-align: left;
}
.panel-toggle:focus-visible {
    outline: 2px solid var(--color-accent);
    outline-offset: -2px;
}
.panel-toggle h4 {
    font-size: 12px;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--color-text-disabled);
    margin: 0;
    font-weight: 600;
    flex: 1;
}
.panel-toggle .chevron {
    width: 12px;
    height: 12px;
    color: var(--color-text-disabled);
    transition: transform 0.15s;
    flex-shrink: 0;
}

/* Collapsed state: hide body, rotate chevron */
.panel-section.collapsed .panel-toggle .chevron {
    transform: rotate(-90deg);
}
.panel-section.collapsed .panel-body {
    display: none;
}

/* Section body */
.panel-body {
    padding: 0 var(--space-4) var(--space-4);
}

/* Property rows (Layout app style) */
.prop-row {
    display: flex;
    gap: var(--space-2);
    margin-bottom: var(--space-2);
    align-items: center;
}
.prop-row:last-child {
    margin-bottom: 0;
}
.prop-row label {
    display: flex;
    align-items: center;
    gap: var(--space-1);
    flex: 1;
    font-size: 12px;
    color: var(--color-text-muted);
}
.prop-row label input,
.prop-row label select,
.prop-row label textarea {
    flex: 1;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    color: var(--color-text);
    padding: var(--space-1) var(--space-2);
    border-radius: var(--radius-sm);
    font-size: 16px;
    min-height: 44px;
    outline: none;
    font-family: inherit;
}
.prop-row label input[type="color"] {
    flex: 0;
    min-width: 44px;
    min-height: 44px;
    cursor: pointer;
    padding: var(--space-1);
}
.prop-row label input[type="color"]::-webkit-color-swatch-wrapper { padding: 0; }
.prop-row label input[type="color"]::-webkit-color-swatch { border: none; border-radius: 2px; }
.prop-row label textarea {
    resize: vertical;
    font-family: inherit;
}
.prop-row label select {
    cursor: pointer;
}
.prop-row label input[type="number"]:focus,
.prop-row label select:focus,
.prop-row label textarea:focus {
    border-color: var(--color-accent);
}

/* Range input */
.prop-row label input[type="range"] {
    width: 100%;
    height: 4px;
    -webkit-appearance: none;
    appearance: none;
    background: var(--color-border);
    border-radius: 2px;
    outline: none;
    cursor: pointer;
    padding: 0;
    border: none;
    min-width: 0;
}
.prop-row label input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 14px;
    height: 14px;
    background: var(--color-accent);
    border-radius: 50%;
    cursor: pointer;
}

/* Checkbox label */
.prop-row .checkbox-label {
    display: flex !important;
    align-items: center;
    gap: var(--space-2);
    cursor: pointer;
    color: var(--color-text) !important;
    font-size: 12px !important;
}
.prop-row .checkbox-label input[type="checkbox"] {
    width: auto;
    accent-color: var(--color-accent);
}

/* Show/hide panel sections */
.panel-shape.hidden,
.panel-conn.hidden,
.panel-custom.hidden,
.panel-project.hidden { display: none; }

/* ===== Context Menu ===== */
#context-menu {
    position: fixed;
    background: var(--color-context-bg);
    border: 1px solid var(--color-border-input);
    border-radius: var(--radius-md);
    padding: var(--space-1);
    min-width: 160px;
    z-index: 2000;
    box-shadow: var(--shadow-lg);
}
#context-menu.hidden { display: none; }

.context-item {
    padding: var(--space-3) var(--space-4);
    font-size: 16px; color: var(--color-text);
    cursor: pointer;
    border-radius: var(--radius-sm);
    transition: background 0.1s;
    min-height: 44px;
    display: flex; align-items: center;
}
.context-item:hover { background: var(--color-btn-hover-bg); }
.context-item.danger { color: var(--color-danger, #DC2626); }
.context-item.danger:hover { background: var(--color-danger-soft, rgba(220, 38, 38, 0.1)); }

.context-divider {
    height: 1px;
    background: var(--color-border-input);
    margin: var(--space-1) var(--space-2);
}

/* ===== Text Editor ===== */
#text-editor { position: fixed; z-index: 1500; display: none; }
#text-editor.visible { display: block; }

#text-input {
    background: var(--color-input-bg);
    border: 2px solid var(--color-accent);
    border-radius: var(--radius-sm);
    color: var(--color-text);
    font-size: 16px;
    padding: var(--space-2);
    outline: none;
    resize: none;
    font-family: inherit;
    min-width: 100px; min-height: 40px;
}

/* ===== Selection Box ===== */
.selection-box {
    position: absolute;
    border: 1px dashed var(--color-accent);
    background: var(--color-accent-soft);
    pointer-events: none;
}

/* Snap highlight during line drawing */
.snap-highlight {
    position: absolute;
    box-shadow: 0 0 0 2px var(--color-accent), 0 0 16px var(--color-accent-soft);
    pointer-events: none;
    z-index: 4;
    border-radius: 2px;
}

/* ===== Action Log (inside properties panel) ===== */
.panel-log {
    border-top: 1px solid var(--color-border);
    overflow: hidden;
    max-height: var(--space-5);
    transition: max-height 0.2s;
    flex-shrink: 0;
}
.panel-log.open { max-height: 200px; }
.log-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 2px var(--space-3);
    font-size: 12px;
    color: var(--color-text-muted);
    cursor: pointer;
    user-select: none;
    flex-shrink: 0;
}
.log-header button {
    background: none; border: none; color: var(--color-text-muted);
    cursor: pointer; font-size: 14px; padding: 0 var(--space-1);
}
.log-body {
    flex: 1;
    overflow-y: auto;
    padding: 2px var(--space-3) var(--space-1);
    font-family: 'SF Mono', 'JetBrains Mono', monospace;
    font-size: 12px;
    color: var(--color-text-muted);
    line-height: 1.5;
}
.log-body .log-entry {
    padding: 1px 0;
    border-bottom: 1px solid var(--color-border);
}
.log-body .log-entry:last-child { border-bottom: none; }
.log-body .log-time { color: var(--color-accent); margin-right: var(--space-1); }
.log-body .log-add { color: var(--color-text); font-weight: 600; }
.log-body .log-del { color: var(--color-text-muted); text-decoration: line-through; }
.log-body .log-edit { color: var(--color-text); font-style: italic; }
.log-body .log-move { color: var(--color-text); }
.log-body .log-sys { color: var(--color-text-muted); font-style: italic; }


/* ===== Layers Tab ===== */
.panel-layers-content {
    flex: 1;
    overflow-y: auto;
    padding: var(--space-1);
    font-size: 12px;
}

/* Layer list container */
.panel-layers-content .layer-list {
    display: flex;
    flex-direction: column;
    gap: var(--space-1);
}

/* Layer item — polished to match Layout app */
.panel-layers-content .layer-item {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-2);
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-size: 12px;
    color: var(--color-text-muted);
    transition: all 0.1s;
    min-height: 44px;
}
.panel-layers-content .layer-item:hover {
    background: var(--color-border);
}
.panel-layers-content .layer-item.active {
    background: var(--color-accent-soft);
    color: var(--color-accent);
}

/* Layer icon column */
.panel-layers-content .layer-icon {
    width: 16px;
    height: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}
.panel-layers-content .layer-icon svg {
    width: 16px;
    height: 16px;
    stroke: currentColor;
    fill: none;
    stroke-width: 2;
    stroke-linecap: round;
    stroke-linejoin: round;
}

/* Layer name */
.panel-layers-content .layer-name {
    flex: 1;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

/* Visibility toggle — 44×44 touch target */
.panel-layers-content .layer-vis-toggle {
    min-width: 44px;
    min-height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    opacity: 0.4;
    border-radius: var(--radius-sm);
    color: var(--color-icon-default);
    background: transparent;
    border: none;
    padding: 10px;
    flex-shrink: 0;
    transition: opacity 0.1s;
}
.panel-layers-content .layer-vis-toggle:hover {
    opacity: 0.8;
}
.panel-layers-content .layer-vis-toggle.hidden {
    opacity: 0.2;
}
.panel-layers-content .layer-vis-toggle svg {
    width: 16px;
    height: 16px;
    stroke: currentColor;
    fill: none;
    stroke-width: 2;
    stroke-linecap: round;
    stroke-linejoin: round;
}

/* Z-height input */
.panel-layers-content .layer-z {
    width: 48px;
    height: 26px;
    min-width: 48px;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    color: var(--color-text);
    font-size: 12px;
    text-align: center;
    padding: 1px;
    flex-shrink: 0;
}
.panel-layers-content .layer-z:focus {
    border-color: var(--color-accent);
    outline: none;
}

/* ===== Export dropdown ===== */
.export-wrap { position: relative; }
.export-drop {
    position: fixed; margin-top: var(--space-1);
    background: var(--color-surface); border: 1px solid var(--color-border);
    border-radius: var(--radius-md); padding: var(--space-1); display: none; flex-direction: column;
    z-index: 3000; min-width: 160px; box-shadow: var(--shadow-md);
}
.export-drop.visible { display: flex; }
.export-item {
    padding: var(--space-3) var(--space-4); font-size: 16px; color: var(--color-text);
    cursor: pointer; border-radius: var(--radius-sm); user-select: none;
    min-height: 44px; display: flex; align-items: center;
}
.export-item:hover { background: var(--color-input-bg); color: var(--color-accent); }

/* ===== Canvas size dropdown ===== */
.canvas-size-wrap {
    position: relative;
}
.canvas-size-drop {
    position: absolute;
    top: 100%; right: 0;
    margin-top: var(--space-1);
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: var(--space-3) var(--space-3);
    display: none;
    flex-direction: column;
    gap: var(--space-1);
    z-index: 200;
    min-width: 200px;
    box-shadow: var(--shadow-md);
}
.canvas-size-drop.visible {
    display: flex;
}
.canvas-size-drop label {
    font-size: 12px;
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}
.canvas-size-drop input[type="number"] {
    width: 100%;
    height: 34px;
    padding: 0 var(--space-3);
    border: 1px solid var(--color-border-input);
    border-radius: var(--radius-sm);
    background: var(--color-input-bg);
    color: var(--color-text);
    font-size: 16px;
}
.canvas-size-drop input[type="number"]:focus {
    outline: none;
    border-color: var(--color-accent);
}

/** ===== Scrollbar ===== */
::-webkit-scrollbar { width: var(--space-2); height: var(--space-2); }
::-webkit-scrollbar-track { background: var(--color-scrollbar-track); }
::-webkit-scrollbar-thumb { background: var(--color-scrollbar-thumb); border-radius: var(--radius-sm); }
::-webkit-scrollbar-thumb:hover { background: var(--color-scrollbar-thumb-hover); }

/* ===== Responsive: small screens ===== */
@media (max-width: 768px) {
    #properties-panel {
        display: none !important;
    }
    #canvas-container {
        right: 0;
    }
}

/* ===== Read-Only Banner ===== */
.readonly-banner {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    background: var(--color-warning);
    color: #fff;
    text-align: center;
    padding: 6px var(--space-4);
    font-size: 13px;
    font-weight: 500;
    letter-spacing: 0.01em;
}

/* Dim toolbar buttons in read-only mode */
body.read-only-mode #toolbar button:not(#theme-toggle):not(#btn-zoom-in):not(#btn-zoom-out):not(#btn-collapse-panel),
body.read-only-mode #toolbar input,
body.read-only-mode #toolbar select {
    opacity: 0.4;
    pointer-events: none;
}
body.read-only-mode #toolbar {
    cursor: not-allowed;
}

/* ===== Save button auto-save dot ===== */
.save-btn {
    position: relative;
    overflow: visible;
}
.save-dot {
    position: absolute;
    bottom: -1px;
    left: 50%;
    transform: translateX(-50%);
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--color-success);
    border: 1.5px solid var(--color-bg);
    pointer-events: none;
}

@media (max-width: 480px) {
    .export-wrap .tool-btn-primary,
    .shape-btn[data-shape="triangle"],
    .shape-btn[data-shape="terminator"] {
        display: none;
    }
    #toolbar {
        gap: 2px;
        padding: 0 var(--space-1);
    }
}

/* ==========================================================================
   DataViz — chart workspace & panel controls
   ========================================================================== */

/* The chart canvas fills the workspace; a transformed page holds the charts. */
#canvas-container {
    position: fixed;
    top: 60px; left: 0; right: 0; bottom: 0;
    overflow: hidden;
    background: var(--color-oob-bg, var(--color-bg-subtle));
    touch-action: none;
    -webkit-user-select: none;
    cursor: default;
}
#canvas-container.panning { cursor: grabbing; }

#chart-stage {
    position: absolute;
    inset: 0;
    overflow: hidden;
}

#chart-canvas {
    position: absolute;
    top: 0; left: 0;
    transform-origin: 0 0;
    background: var(--color-surface);
    box-shadow: var(--shadow-md);
}

#grid-layer {
    position: absolute;
    top: 0; left: 0;
    width: 100%; height: 100%;
    pointer-events: none;
    z-index: 0;
    background-image:
        linear-gradient(to right, var(--color-border) 1px, transparent 1px),
        linear-gradient(to bottom, var(--color-border) 1px, transparent 1px);
    background-size: 20px 20px;
    opacity: 0.5;
}
#grid-layer.hidden { display: none; }

#charts-layer {
    position: absolute;
    top: 0; left: 0;
    width: 100%; height: 100%;
    z-index: 1;
}

/* ---- Chart nodes ---- */
.chart-node {
    position: absolute;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    cursor: move;
    user-select: none;
    transition: box-shadow 0.12s, border-color 0.12s;
    overflow: visible;
}
.chart-node:hover { box-shadow: var(--shadow-md); }
.chart-node.selected {
    border-color: var(--color-accent);
    box-shadow: 0 0 0 2px var(--color-accent), var(--shadow-md);
    cursor: move;
}
.chart-node.dragging { opacity: 0.9; }

.chart-node-header {
    position: absolute;
    top: -28px; left: -1px; right: -1px;
    height: 26px;
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 0 8px;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-bottom: none;
    border-radius: var(--radius-sm) var(--radius-sm) 0 0;
    font-size: 11px;
    font-weight: 600;
    color: var(--color-text-muted);
    pointer-events: none;
    opacity: 0;
    transition: opacity 0.12s;
    white-space: nowrap;
    overflow: hidden;
}
.chart-node.selected .chart-node-header,
.chart-node:hover .chart-node-header { opacity: 1; }
.chart-node-header .node-type {
    color: var(--color-accent);
    text-transform: uppercase;
    letter-spacing: 0.04em;
    font-size: 10px;
}
.chart-node-header .node-name { color: var(--color-text); overflow: hidden; text-overflow: ellipsis; }

.chart-node-body {
    position: absolute;
    inset: 0;
    border-radius: var(--radius-md);
    overflow: hidden;
}
.chart-node-body svg {
    display: block;
    width: 100%; height: 100%;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
}
.chart-node-body .chart-error {
    border: none; background: none; min-height: 0; max-width: none;
}

/* Resize handles */
.chart-node .resize-handle {
    position: absolute;
    width: 12px; height: 12px;
    background: var(--color-surface);
    border: 2px solid var(--color-accent);
    border-radius: 3px;
    z-index: 10;
}
.chart-node .resize-handle.nw { left: -6px; top: -6px; cursor: nwse-resize; }
.chart-node .resize-handle.ne { right: -6px; top: -6px; cursor: nesw-resize; }
.chart-node .resize-handle.sw { left: -6px; bottom: -6px; cursor: nesw-resize; }
.chart-node .resize-handle.se { right: -6px; bottom: -6px; cursor: nwse-resize; }
.chart-node .resize-handle.n { left: 50%; top: -6px; margin-left: -6px; cursor: ns-resize; }
.chart-node .resize-handle.s { left: 50%; bottom: -6px; margin-left: -6px; cursor: ns-resize; }
.chart-node .resize-handle.w { left: -6px; top: 50%; margin-top: -6px; cursor: ew-resize; }
.chart-node .resize-handle.e { right: -6px; top: 50%; margin-top: -6px; cursor: ew-resize; }
.chart-node .resize-handle:hover { background: var(--color-accent); }

/* Rubber-band selection box */
#selection-box {
    position: absolute;
    display: none;
    border: 1px solid var(--color-accent);
    background: var(--color-accent-soft);
    pointer-events: none;
    z-index: 50;
}

.canvas-hint {
    position: absolute;
    left: 50%;
    bottom: 12px;
    transform: translateX(-50%);
    padding: 6px 14px;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: 999px;
    font-size: 11px;
    color: var(--color-text-muted);
    box-shadow: var(--shadow-sm);
    pointer-events: none;
    z-index: 60;
    opacity: 1;
    transition: opacity 0.4s;
}
.canvas-hint.faded { opacity: 0; }

.tool-label { margin-left: 6px; font-size: 12px; font-weight: 600; }

/* Selected-chart indicator in the panel */
.chart-selection {
    display: flex;
    align-items: center;
    gap: 8px;
    margin: var(--space-3) var(--space-3) 0;
    padding: var(--space-2) var(--space-3);
    background: var(--color-bg-subtle);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    font-size: 12px;
    color: var(--color-text-muted);
}
.chart-selection .sel-dot {
    width: 8px; height: 8px;
    border-radius: 50%;
    background: var(--color-text-disabled);
    flex: none;
}
.chart-selection.has-selection {
    border-color: var(--color-accent);
    color: var(--color-text);
}
.chart-selection.has-selection .sel-dot { background: var(--color-accent); }

/* ---- Empty state / drop zone ---- */
.chart-empty {
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
    display: flex;
    align-items: center;
    justify-content: center;
    width: min(560px, calc(100% - 48px));
    min-height: 300px;
    color: var(--color-text-muted);
    text-align: center;
    border: 2px dashed var(--color-border);
    border-radius: var(--radius-lg);
    background: var(--color-surface);
    padding: var(--space-6);
    z-index: 40;
}
.chart-empty.dragover {
    border-color: var(--color-accent);
    background: var(--color-accent-soft);
}
.drop-inner svg {
    color: var(--color-accent);
    margin-bottom: var(--space-3);
}
.drop-inner h2 {
    font-size: 20px;
    font-weight: 700;
    color: var(--color-text);
    margin-bottom: var(--space-2);
    letter-spacing: -0.01em;
}
.drop-inner p {
    font-size: 14px;
    margin-bottom: var(--space-2);
}
.drop-hint {
    max-width: 420px;
    margin: var(--space-4) auto 0 !important;
    font-size: 12px !important;
    color: var(--color-text-disabled);
    line-height: 1.6;
}
.link-btn {
    background: none;
    border: none;
    color: var(--color-accent);
    font: inherit;
    font-weight: 600;
    cursor: pointer;
    text-decoration: underline;
    padding: 0 2px;
}
.link-btn:hover { color: var(--color-accent-hover); }
.sample-btn {
    margin-top: var(--space-4);
    padding: var(--space-2) var(--space-5);
    min-height: 44px;
    background: var(--color-accent);
    color: #fff;
    border: none;
    border-radius: var(--radius-sm);
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    font-family: inherit;
    transition: background 0.15s;
}
.sample-btn:hover { background: var(--color-accent-hover); }

/* ---- Drag overlay ---- */
.drop-overlay {
    position: fixed;
    inset: 60px 0 0 0;
    z-index: 1500;
    display: none;
    align-items: center;
    justify-content: center;
    background: var(--color-accent-soft);
    border: 3px dashed var(--color-accent);
    pointer-events: none;
}
.drop-overlay.visible { display: flex; }
.drop-overlay-inner {
    font-size: 22px;
    font-weight: 700;
    color: var(--color-accent);
    background: var(--color-surface);
    padding: var(--space-4) var(--space-6);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
}

/* ---- Data source summary ---- */
.source-file {
    font-size: 13px;
    font-weight: 600;
    color: var(--color-text);
    word-break: break-all;
    margin-bottom: var(--space-1);
}
.source-meta {
    font-size: 12px;
    color: var(--color-text-muted);
    margin-bottom: var(--space-2);
}
.source-actions {
    display: flex;
    gap: var(--space-2);
}
.mini-action {
    flex: 1;
    min-height: 36px;
    padding: var(--space-1) var(--space-2);
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    color: var(--color-text);
    font-size: 13px;
    font-family: inherit;
    font-weight: 600;
    cursor: pointer;
    transition: border-color 0.15s, color 0.15s;
}
.mini-action:hover {
    border-color: var(--color-accent);
    color: var(--color-accent);
}

/* ---- Field blocks ---- */
.field-block { margin-bottom: var(--space-2); }
.field-label {
    font-size: 12px;
    color: var(--color-text-muted);
    margin-bottom: var(--space-1);
}
.column-checklist {
    display: flex;
    flex-direction: column;
    gap: 2px;
    max-height: 190px;
    overflow-y: auto;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    padding: var(--space-1);
    background: var(--color-surface);
}
.column-checklist .empty-note {
    font-size: 12px;
    color: var(--color-text-disabled);
    padding: var(--space-2);
    font-style: italic;
}
.check-row {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-1) var(--space-2);
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-size: 13px;
    color: var(--color-text);
    min-height: 32px;
}
.check-row:hover { background: var(--color-bg-subtle); }
.check-row input { accent-color: var(--color-accent); }
.check-row .col-name {
    flex: 1;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}
.check-row .col-type { font-size: 10px; }

/* ---- Type badges ---- */
.type-badge {
    display: inline-block;
    font-size: 10px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    padding: 1px 6px;
    border-radius: 999px;
    background: var(--color-border);
    color: var(--color-text-muted);
    flex-shrink: 0;
}
.type-badge.number { background: rgba(37, 99, 235, 0.14); color: var(--color-accent); }
.type-badge.date   { background: rgba(217, 119, 6, 0.16); color: var(--color-warning); }
.type-badge.boolean{ background: rgba(22, 163, 74, 0.16); color: var(--color-success); }

/* ---- Column list (Data tab) ---- */
.column-list { display: flex; flex-direction: column; gap: 2px; }
.column-item {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-2);
    border-radius: var(--radius-sm);
    min-height: 40px;
}
.column-item:hover { background: var(--color-bg-subtle); }
.column-item .col-name {
    flex: 1;
    font-size: 13px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}
.col-assign {
    display: flex;
    gap: 2px;
    flex-shrink: 0;
}
.col-assign button {
    width: 30px;
    height: 30px;
    border: 1px solid var(--color-border);
    background: var(--color-surface);
    color: var(--color-text-muted);
    border-radius: var(--radius-sm);
    font-size: 11px;
    font-weight: 700;
    cursor: pointer;
    font-family: inherit;
}
.col-assign button:hover { border-color: var(--color-accent); color: var(--color-accent); }
.col-assign button.on { background: var(--color-accent); border-color: var(--color-accent); color: #fff; }

/* ---- Data preview table ---- */
.data-preview {
    overflow: auto;
    max-height: 340px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    font-size: 12px;
}
.data-preview table { border-collapse: collapse; width: max-content; min-width: 100%; }
.data-preview th,
.data-preview td {
    border-bottom: 1px solid var(--color-border);
    border-right: 1px solid var(--color-border);
    padding: 4px 8px;
    text-align: left;
    white-space: nowrap;
    max-width: 220px;
    overflow: hidden;
    text-overflow: ellipsis;
}
.data-preview th {
    position: sticky;
    top: 0;
    background: var(--color-bg-subtle);
    color: var(--color-text-muted);
    font-weight: 600;
    z-index: 1;
}
.data-preview tr:nth-child(even) td { background: var(--color-bg-subtle); }
.data-preview td.num { text-align: right; font-variant-numeric: tabular-nums; }

/* ---- Display toggles ---- */
.display-toggles {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-1);
}
.display-toggles .checkbox-label { min-height: 32px; }

/* ---- Chart tooltip (HTML overlay) ---- */
.chart-tooltip {
    position: fixed;
    z-index: 1600;
    pointer-events: none;
    background: var(--color-context-bg);
    border: 1px solid var(--color-border-input);
    border-radius: var(--radius-sm);
    padding: var(--space-2) var(--space-3);
    font-size: 12px;
    color: var(--color-text);
    box-shadow: var(--shadow-md);
    max-width: 260px;
    line-height: 1.5;
}
.chart-tooltip.hidden { display: none; }
.chart-tooltip .tt-title { font-weight: 700; margin-bottom: 2px; }
.chart-tooltip .tt-row { display: flex; justify-content: space-between; gap: var(--space-3); }
.chart-tooltip .tt-key { display: inline-flex; align-items: center; gap: 5px; }
.chart-tooltip .tt-swatch {
    width: 9px; height: 9px; border-radius: 2px; display: inline-block; flex-shrink: 0;
}
.chart-tooltip .tt-val { font-variant-numeric: tabular-nums; font-weight: 600; }

/* SVG hit targets */
.hit { cursor: pointer; }

/* Empty / status notes */
.empty-note {
    padding: var(--space-3);
    font-size: 12px;
    color: var(--color-text-muted);
    text-align: center;
}
.preview-note {
    padding: var(--space-2) var(--space-3);
    font-size: 11px;
    color: var(--color-text-muted);
    border-top: 1px solid var(--color-border);
    background: var(--color-bg-subtle);
    position: sticky;
    bottom: 0;
}
.chart-error {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 240px;
    max-width: 420px;
    margin: auto;
    padding: var(--space-5);
    text-align: center;
    font-size: 14px;
    line-height: 1.6;
    color: var(--color-text-muted);
    border: 1px dashed var(--color-border);
    border-radius: var(--radius-lg);
    background: var(--color-bg-subtle);
}

/* Responsive chart workspace */
@media (max-width: 768px) {
    .chart-node-body svg { box-shadow: none; }
    .chart-node .resize-handle { width: 16px; height: 16px; }
    .chart-node .resize-handle.nw { left: -8px; top: -8px; }
    .chart-node .resize-handle.ne { right: -8px; top: -8px; }
    .chart-node .resize-handle.sw { left: -8px; bottom: -8px; }
    .chart-node .resize-handle.se { right: -8px; bottom: -8px; }
    .chart-node .resize-handle.n { top: -8px; }
    .chart-node .resize-handle.s { bottom: -8px; }
    .chart-node .resize-handle.w { left: -8px; }
    .chart-node .resize-handle.e { right: -8px; }
    .tool-label { display: none; }
}