* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    background-color: #f5f7fa;
    color: #333;
    overflow: hidden;
}

.app-container {
    display: flex;
    height: 100vh;
    width: 100vw;
}

/* Toolbar */
.toolbar {
    width: 250px;
    background-color: #2c3e50;
    color: white;
    padding: 20px 15px;
    display: flex;
    flex-direction: column;
    gap: 15px;
    overflow-y: auto;
    flex-shrink: 0;
}

.toolbar h2 {
    font-size: 1.2rem;
    margin-bottom: 10px;
    text-align: center;
    color: #ecf0f1;
    border-bottom: 1px solid #34495e;
    padding-bottom: 10px;
}

.tool-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.tool-group h3 {
    font-size: 0.9rem;
    color: #bdc3c7;
    margin-bottom: 5px;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.tool-btn, #btn-clear, #btn-reset-view, #btn-export, #btn-save, #btn-load {
    background-color: #34495e;
    color: #ecf0f1;
    border: 1px solid #2c3e50;
    padding: 8px 12px;
    text-align: left;
    border-radius: 4px;
    cursor: pointer;
    transition: background-color 0.2s;
    font-size: 0.95rem;
}

.tool-btn:hover, #btn-clear:hover, #btn-reset-view:hover, #btn-export:hover, #btn-save:hover, #btn-load:hover {
    background-color: #3b536b;
}

.tool-btn.active {
    background-color: #3498db;
    border-color: #2980b9;
    color: white;
    font-weight: bold;
}

#btn-clear {
    background-color: #e74c3c;
    text-align: center;
}

#btn-clear:hover {
    background-color: #c0392b;
}

#btn-export {
    background-color: #2ecc71;
    text-align: center;
}

#btn-export:hover {
    background-color: #27ae60;
}

#btn-reset-view {
    text-align: center;
}

#btn-save, #btn-load {
    background-color: #f39c12;
    text-align: center;
}

#btn-save:hover, #btn-load:hover {
    background-color: #d68910;
}


/* Canvas Area */
.canvas-wrapper {
    flex-grow: 1;
    position: relative;
    background-color: #ffffff;
    background-image: 
        linear-gradient(#ecf0f1 1px, transparent 1px),
        linear-gradient(90deg, #ecf0f1 1px, transparent 1px);
    background-size: 20px 20px; /* This will be overridden by JS drawing */
    background-position: center;
}

canvas {
    display: block;
    width: 100%;
    height: 100%;
    cursor: crosshair;
}

.canvas-info {
    position: absolute;
    bottom: 10px;
    left: 10px;
    background: rgba(255, 255, 255, 0.9);
    padding: 5px 10px;
    border-radius: 4px;
    font-size: 0.85rem;
    box-shadow: 0 1px 3px rgba(0,0,0,0.2);
    pointer-events: none;
}

/* Properties Panel */
.properties-panel {
    width: 300px;
    background-color: #ffffff;
    border-left: 1px solid #ddd;
    padding: 20px 15px;
    display: flex;
    flex-direction: column;
    overflow-y: auto;
    flex-shrink: 0;
    box-shadow: -2px 0 5px rgba(0,0,0,0.05);
}

.properties-panel h2 {
    font-size: 1.2rem;
    margin-bottom: 15px;
    color: #2c3e50;
    border-bottom: 1px solid #eee;
    padding-bottom: 10px;
}

#no-selection {
    color: #7f8c8d;
    font-size: 0.9rem;
    text-align: center;
    margin-top: 20px;
}

.prop-group {
    margin-bottom: 15px;
}

.prop-group label {
    display: block;
    font-size: 0.85rem;
    color: #34495e;
    margin-bottom: 5px;
    font-weight: 600;
}

.prop-group input {
    width: 100%;
    padding: 6px 10px;
    border: 1px solid #ccc;
    border-radius: 4px;
    font-size: 0.95rem;
}

.prop-group input:focus {
    border-color: #3498db;
    outline: none;
}

.btn-delete {
    background-color: #e74c3c;
    color: white;
    border: none;
    padding: 8px;
    width: 100%;
    border-radius: 4px;
    cursor: pointer;
    font-weight: bold;
    margin-top: 10px;
}

.btn-delete:hover {
    background-color: #c0392b;
}