:root {
    --bg-dark: #1a1a1a;
    --bg-panel: #252525;
    --bg-input: #2d2d2d;
    --accent: #3b82f6;
    --accent-hover: #2563eb;
    --text: #e5e5e5;
    --text-muted: #888;
    --border: #404040;
    --success: #22c55e;

    --canvas-bg: #ffffff;
    --shape-fill: #ffffff;
    --shape-stroke: #000000;
    --node-font-size: 14px;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg-dark);
    color: var(--text);
    height: 100vh;
    overflow: hidden;
}

/* Header */
header {
    background: var(--bg-panel);
    border-bottom: 1px solid var(--border);
    padding: 0.75rem 1.5rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 56px;
}

.header-left {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

.logo {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text);
    letter-spacing: -0.02em;
}

.toolbar {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.toolbar-divider {
    width: 1px;
    height: 24px;
    background: var(--border);
    margin: 0 0.25rem;
}

.tool-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 36px;
    border: 1px solid var(--border);
    border-radius: 6px;
    background: var(--bg-input);
    color: var(--text);
    cursor: pointer;
    transition: all 0.15s ease;
}

.tool-btn:hover {
    border-color: var(--accent);
    color: var(--accent);
}

.tool-btn.active {
    background: var(--accent);
    border-color: var(--accent);
    color: white;
}

.tool-btn:disabled {
    opacity: 0.4;
    cursor: not-allowed;
}

.tool-btn:disabled:hover {
    border-color: var(--border);
    color: var(--text);
}

.zoom-display {
    font-size: 0.8rem;
    color: var(--text-muted);
    min-width: 45px;
    text-align: center;
}

.header-controls {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

/* Buttons */
button {
    font-family: inherit;
    font-size: 0.85rem;
    cursor: pointer;
}

.btn-primary {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    padding: 0.5rem 0.75rem;
    border-radius: 6px;
    border: 1px solid var(--accent);
    background: var(--accent);
    color: white;
    transition: all 0.15s ease;
}

.btn-primary:hover {
    background: var(--accent-hover);
    border-color: var(--accent-hover);
}

.btn-primary svg {
    width: 16px;
    height: 16px;
}

/* File Input */
.file-input {
    display: none;
}

.file-label {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    padding: 0.5rem 0.75rem;
    border-radius: 6px;
    border: 1px solid var(--border);
    background: var(--bg-input);
    color: var(--text);
    font-size: 0.85rem;
    cursor: pointer;
    transition: all 0.15s ease;
}

.file-label:hover {
    border-color: var(--accent);
}

.file-label svg {
    width: 16px;
    height: 16px;
}

/* Dropdown */
.dropdown {
    position: relative;
}

.dropdown-menu {
    display: none;
    position: absolute;
    top: 100%;
    right: 0;
    margin-top: 0.25rem;
    background: var(--bg-panel);
    border: 1px solid var(--border);
    border-radius: 6px;
    overflow: hidden;
    z-index: 100;
    min-width: 160px;
}

.dropdown-menu.show {
    display: block;
}

.dropdown-menu button {
    display: block;
    width: 100%;
    padding: 0.6rem 0.75rem;
    border: none;
    background: transparent;
    color: var(--text);
    text-align: left;
    transition: background 0.15s ease;
}

.dropdown-menu button:hover {
    background: var(--bg-input);
}

.dropdown-menu button svg {
    vertical-align: middle;
    margin-right: 8px;
}

.dropdown-divider {
    height: 1px;
    background: var(--border);
    margin: 4px 0;
}

.align-menu {
    left: 0;
    right: auto;
}

/* Settings Button */
.settings-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    border: 1px solid var(--border);
    border-radius: 6px;
    background: var(--bg-input);
    color: var(--text-muted);
    transition: all 0.15s ease;
}

.settings-btn:hover {
    color: var(--text);
    border-color: var(--accent);
}

.settings-btn svg {
    width: 20px;
    height: 20px;
}

/* Canvas Container */
.canvas-container {
    height: calc(100vh - 56px);
    overflow: hidden;
    position: relative;
    background: var(--bg-dark);
}

.canvas-container.panning {
    cursor: grabbing;
}

.canvas-wrapper {
    position: absolute;
    transform-origin: 0 0;
}

.flowchart-canvas {
    background: var(--canvas-bg);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
    width: 3000px;
    height: 2000px;
}

.flowchart-canvas.inverted {
    --canvas-bg: #1a1a1a;
    --shape-fill: #1a1a1a;
    --shape-stroke: #ffffff;
    background: var(--canvas-bg);
}

/* Grid */
.grid-pattern line {
    stroke: #cccccc;
    stroke-width: 0.5;
}

.grid-pattern line.center-line {
    stroke: #aaaaaa;
    stroke-width: 1;
}

.flowchart-canvas.inverted .grid-pattern line {
    stroke: #444444;
}

.flowchart-canvas.inverted .grid-pattern line.center-line {
    stroke: #666666;
    stroke-width: 1;
}

/* SVG Shapes */
.node {
    cursor: move;
}

.node.selected .shape {
    stroke: var(--accent);
    stroke-width: 3;
}

.shape {
    fill: var(--shape-fill);
    stroke: var(--shape-stroke);
    stroke-width: 2;
}

.node foreignObject {
    overflow: visible;
}

.node-text {
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    font-family: 'Inter', sans-serif;
    font-size: var(--node-font-size);
    color: var(--shape-stroke);
    word-wrap: break-word;
    overflow-wrap: break-word;
    padding: 4px;
    outline: none;
    height: 100%;
    line-height: 1.3;
    pointer-events: auto;
    cursor: text;
    user-select: text;
    -webkit-user-select: text;
}

.node-text:focus {
    background: rgba(59, 130, 246, 0.1);
    outline: 2px solid var(--accent);
    outline-offset: -2px;
}

/* Resize Handles */
.resize-handle {
    fill: var(--accent);
    stroke: white;
    stroke-width: 1;
    cursor: nwse-resize;
    opacity: 0;
    transition: opacity 0.15s ease;
}

.resize-handle.ne,
.resize-handle.sw {
    cursor: nesw-resize;
}

.node.selected .resize-handle {
    opacity: 1;
}

/* Connections */
.connection-path {
    fill: none;
    stroke: var(--shape-stroke);
    stroke-width: 2;
    cursor: pointer;
}

.connection-path:hover {
    stroke-width: 3;
}

.connection.selected .connection-path {
    stroke: var(--accent);
    stroke-width: 3;
}

.arrow-marker {
    fill: var(--shape-stroke);
}

.connection-label {
    font-family: 'Inter', sans-serif;
    font-size: 12px;
    fill: var(--shape-stroke);
}

.control-point {
    fill: var(--accent);
    stroke: white;
    stroke-width: 2;
    cursor: move;
    opacity: 0;
}

.connection.selected .control-point {
    opacity: 1;
}

.temp-connection {
    stroke: var(--accent);
    stroke-width: 2;
    stroke-dasharray: 5, 5;
    pointer-events: none;
}

/* Connection Points */
.connection-point {
    fill: var(--accent);
    opacity: 0;
    cursor: crosshair;
    transition: opacity 0.15s ease;
}

.node:hover .connection-point,
.node.selected .connection-point {
    opacity: 0.7;
}

.node:hover .connection-point:hover {
    opacity: 1;
    r: 8;
}

/* Modal */
.modal-overlay {
    display: none;
    position: fixed;
    top: 56px;
    right: 0;
    bottom: 0;
    left: auto;
    background: transparent;
    z-index: 1000;
    align-items: flex-start;
    justify-content: flex-end;
    pointer-events: none;
}

.modal-overlay.active {
    display: flex;
}

.modal {
    background: var(--bg-panel);
    border-radius: 12px 0 0 12px;
    border: 1px solid var(--border);
    border-right: none;
    padding: 1.5rem;
    width: 320px;
    max-height: calc(100vh - 56px);
    overflow-y: auto;
    pointer-events: auto;
    box-shadow: -4px 0 20px rgba(0, 0, 0, 0.3);
}

.modal h3 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 1.25rem;
}

.settings-group {
    margin-bottom: 1.25rem;
}

.settings-label {
    display: block;
    font-size: 0.8rem;
    font-weight: 500;
    color: var(--text-muted);
    margin-bottom: 0.5rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.slider-row {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.slider-row input[type="range"] {
    flex: 1;
    height: 6px;
    border-radius: 3px;
    background: var(--bg-input);
    appearance: none;
    cursor: pointer;
}

.slider-row input[type="range"]::-webkit-slider-thumb {
    appearance: none;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: var(--accent);
    cursor: pointer;
}

.slider-value {
    font-size: 0.85rem;
    color: var(--text-muted);
    min-width: 40px;
    text-align: right;
}

.toggle-group {
    display: flex;
    gap: 0.5rem;
}

.toggle-btn {
    flex: 1;
    padding: 0.5rem 0.75rem;
    border: 1px solid var(--border);
    border-radius: 6px;
    background: var(--bg-input);
    color: var(--text);
    font-size: 0.85rem;
    transition: all 0.15s ease;
}

.toggle-btn:hover {
    border-color: var(--accent);
}

.toggle-btn.active {
    background: var(--accent);
    border-color: var(--accent);
    color: white;
}

.checkbox-row {
    display: flex;
    gap: 1.5rem;
}

.checkbox-label {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.85rem;
    color: var(--text);
    cursor: pointer;
}

.checkbox-label input[type="checkbox"] {
    width: 16px;
    height: 16px;
    accent-color: var(--accent);
    cursor: pointer;
}

.modal-close {
    width: 100%;
    margin-top: 0.5rem;
    padding: 0.6rem;
    border: 1px solid var(--border);
    border-radius: 6px;
    background: var(--bg-input);
    color: var(--text);
    font-size: 0.85rem;
    transition: all 0.15s ease;
}

.modal-close:hover {
    border-color: var(--accent);
}

/* Help Modal */
.help-modal {
    width: 380px;
}

.shortcuts-list {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    max-height: calc(100vh - 200px);
    overflow-y: auto;
}

.shortcut-group {
    display: flex;
    flex-direction: column;
    gap: 0.35rem;
}

.shortcut-title {
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--accent);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 0.25rem;
}

.shortcut {
    font-size: 0.85rem;
    color: var(--text-muted);
    display: flex;
    align-items: center;
    gap: 0.35rem;
}

kbd {
    display: inline-block;
    padding: 0.15rem 0.4rem;
    font-family: inherit;
    font-size: 0.75rem;
    color: var(--text);
    background: var(--bg-dark);
    border: 1px solid var(--border);
    border-radius: 4px;
}

/* Toast */
.toast {
    position: fixed;
    bottom: 20px;
    right: 20px;
    background: var(--bg-panel);
    color: var(--text);
    padding: 0.75rem 1rem;
    border-radius: 6px;
    border: 1px solid var(--border);
    opacity: 0;
    transform: translateY(10px);
    transition: all 0.3s ease;
    pointer-events: none;
    z-index: 1001;
}

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

.toast.success {
    border-color: var(--success);
}

/* Connect Mode Cursor */
.canvas-container.connect-mode {
    cursor: crosshair;
}

.canvas-container.connect-mode .node {
    cursor: crosshair;
}

/* Marquee Selection */
.marquee-selection {
    fill: rgba(59, 130, 246, 0.1);
    stroke: var(--accent);
    stroke-width: 1;
    stroke-dasharray: 4, 4;
    pointer-events: none;
}