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

:root {
    --primary-color: #3b82f6;
    --primary-hover: #2563eb;
    --secondary-color: #64748b;
    --background: #f8fafc;
    --surface: #ffffff;
    --border: #e2e8f0;
    --text: #1e293b;
    --text-light: #64748b;
    --shadow: rgba(0, 0, 0, 0.1);
    --shadow-lg: rgba(0, 0, 0, 0.15);
}

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

.app-container {
    display: flex;
    flex-direction: column;
    height: 100vh;
}

header {
    background: var(--surface);
    border-bottom: 1px solid var(--border);
    padding: 0rem 1.5rem;
    box-shadow: 0 1px 3px var(--shadow);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

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

.header-icon {
    width: 64px;
    height: 64px;
    flex-shrink: 0;
}

header h1 {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text);
    margin: 0;
}

.toolbar {
    background: var(--surface);
    border-bottom: 1px solid var(--border);
    padding: 0.75rem 1.5rem;
    display: flex;
    gap: 1.5rem;
    align-items: center;
    flex-wrap: wrap;
    box-shadow: 0 1px 3px var(--shadow);
}

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

.tool-btn {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 0.5rem;
    color: var(--text);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
}

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

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

.tool-btn svg,
.tool-icon {
    width: 20px;
    height: 20px;
    flex-shrink: 0;
}

.vertex-control {
    display: flex;
    align-items: center;
    gap: 0.25rem;
    border: 1px solid var(--border);
    border-radius: 0.5rem;
    overflow: hidden;
}

.vertex-btn {
    width: 32px;
    height: 32px;
    background: var(--surface);
    border: none;
    color: var(--text);
    font-size: 1.25rem;
    cursor: pointer;
    transition: background 0.2s;
}

.vertex-btn:hover {
    background: var(--background);
}

#vertexInput {
    width: 32px;
    height: 32px;
    border: none;
    text-align: center;
    font-size: 0.875rem;
    background: var(--surface);
    color: var(--text);
    /* Remove spinner arrows */
    -moz-appearance: textfield;
    appearance: textfield;
}

#vertexInput::-webkit-outer-spin-button,
#vertexInput::-webkit-inner-spin-button {
    -webkit-appearance: none;
    margin: 0;
}

.color-panel {
    background: var(--surface);
    border-bottom: 1px solid var(--border);
    padding: 1rem 1.5rem;
    box-shadow: 0 1px 3px var(--shadow);
}

.color-controls {
    display: flex;
    gap: 1rem;
    align-items: center;
    flex-wrap: wrap;
}

.color-controls label {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text);
}

.color-slots {
    display: flex;
    gap: 0.5rem;
}

.color-slot {
    width: 50px;
    height: 50px;
    border: 3px solid var(--border);
    border-radius: 0.5rem;
    cursor: pointer;
    transition: all 0.2s;
    box-shadow: 0 1px 2px var(--shadow);
    position: relative;
}

.color-slot:hover {
    transform: scale(1.05);
    box-shadow: 0 2px 4px var(--shadow-lg);
}

.color-slot.selected {
    border-color: var(--primary-color);
    border-width: 4px;
    box-shadow: 0 2px 6px var(--shadow-lg);
}

#colorPicker {
    position: absolute;
    opacity: 0;
    width: 0;
    height: 0;
    pointer-events: none;
}

.save-load-panel,
.export-panel {
    background: var(--surface);
    border-bottom: 1px solid var(--border);
    padding: 1rem 1.5rem;
    box-shadow: 0 1px 3px var(--shadow);
}

.save-load-controls,
.export-controls {
    display: flex;
    gap: 1.5rem;
    align-items: center;
    flex-wrap: wrap;
}

.save-load-group {
    display: flex;
    gap: 0.75rem;
    align-items: center;
}

.save-load-controls label,
.export-controls label {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text);
}

.save-load-buttons,
.export-buttons {
    display: flex;
    gap: 0.5rem;
}

.save-load-format-btn,
.export-format-btn {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 0.5rem;
    color: var(--text);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
}

.save-load-format-btn:hover,
.export-format-btn:hover {
    background: var(--background);
    border-color: var(--primary-color);
}

.save-load-format-btn svg,
.export-format-btn svg,
.export-icon {
    width: 20px;
    height: 20px;
    flex-shrink: 0;
}

.canvas-container {
    flex: 1;
    overflow: hidden;
    background: 
        linear-gradient(45deg, #f0f0f0 25%, transparent 25%),
        linear-gradient(-45deg, #f0f0f0 25%, transparent 25%),
        linear-gradient(45deg, transparent 75%, #f0f0f0 75%),
        linear-gradient(-45deg, transparent 75%, #f0f0f0 75%);
    background-size: 20px 20px;
    background-position: 0 0, 0 10px, 10px -10px, -10px 0px;
}

#canvas {
    width: 100%;
    height: 100%;
    cursor: crosshair;
}

.polygon {
    stroke: #1e293b;
    stroke-width: 2;
    transition: opacity 0.2s;
}

.polygon:hover {
    opacity: 0.8;
}

.polygon-preview {
    stroke: #64748b;
    stroke-width: 2;
    stroke-dasharray: 5,5;
    opacity: 0.6;
    pointer-events: none;
}

.snap-indicator {
    stroke: #ef4444;
    stroke-width: 3;
    fill: none;
    opacity: 0.8;
    pointer-events: none;
}

@media (max-width: 768px) {
    .toolbar {
        padding: 0.5rem 1rem;
    }
    
    .color-controls {
        flex-direction: column;
        align-items: flex-start;
        gap: 1rem;
    }
    
    header h1 {
        font-size: 1.25rem;
    }
}