* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }
        
        body {
            font-family: 'PingFang SC', 'Microsoft YaHei', sans-serif;
            background: #F4F3EC;
            color: #0C0302;
            overflow: hidden;
            height: 100vh;
        }
        
        .container {
            display: flex;
            height: 100vh;
        }
        
        .control-panel {
            width: 320px;
            background: #F4F3EC;
            padding: 20px;
            border-right: 3px solid #FF5600;
            overflow-y: auto;
        }
        
        .title {
            font-size: 28px;
            font-weight: bold;
            color: #0C0302;
            margin-bottom: 30px;
            text-align: left;
        }
        
        .control-group {
            margin-bottom: 25px;
            padding: 15px;
            background: rgba(255, 255, 255, 0.3);
            border-radius: 8px;
        }
        
        .control-label {
            font-size: 18px;
            color: #0C0302;
            margin-bottom: 10px;
            font-weight: bold;
        }
        
        .angle-control {
            margin-bottom: 15px;
        }
        
        .angle-slider {
            width: 100%;
            height: 8px;
            background: #ddd;
            border-radius: 4px;
            outline: none;
            -webkit-appearance: none;
        }
        
        .angle-slider::-webkit-slider-thumb {
            -webkit-appearance: none;
            width: 24px;
            height: 24px;
            background: #FF5600;
            border-radius: 50%;
            cursor: pointer;
        }
        
        .angle-display {
            font-size: 22px;
            color: #FF5600;
            font-weight: bold;
            text-align: center;
            margin-top: 8px;
        }
        
        .tool-buttons {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 12px;
            margin-bottom: 15px;
        }
        
        .tool-btn {
            padding: 14px;
            background: #FF5600;
            color: white;
            border: none;
            border-radius: 8px;
            cursor: pointer;
            font-size: 16px;
            font-weight: bold;
            transition: all 0.3s;
        }
        
        .tool-btn:hover {
            background: #FF8941;
            transform: translateY(-1px);
        }
        
        .tool-btn.active {
            background: #0C0302;
            box-shadow: 0 4px 8px rgba(0,0,0,0.2);
        }
        
        .measure-buttons {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 12px;
            margin-bottom: 15px;
        }
        
        .measure-btn {
            padding: 12px;
            background: #38A169;
            color: white;
            border: none;
            border-radius: 8px;
            cursor: pointer;
            font-size: 15px;
            font-weight: bold;
            transition: all 0.3s;
        }
        
        .measure-btn:hover {
            background: #2F855A;
            transform: translateY(-1px);
        }
        
        .measure-btn.active {
            background: #1A202C;
            box-shadow: 0 4px 8px rgba(0,0,0,0.2);
        }
        
        .action-buttons {
            display: flex;
            flex-direction: column;
            gap: 10px;
        }
        
        .action-btn {
            padding: 12px;
            background: #74706E;
            color: white;
            border: none;
            border-radius: 6px;
            cursor: pointer;
            font-size: 16px;
            transition: all 0.3s;
        }
        
        .action-btn:hover {
            background: #0C0302;
        }
        
        .canvas-container {
            flex: 1;
            position: relative;
            background: white;
            overflow: hidden;
        }
        
        #drawingCanvas {
            display: block;
            cursor: crosshair;
        }
        
        .measurement-info {
            position: absolute;
            top: 20px;
            right: 20px;
            background: rgba(255, 255, 255, 0.95);
            padding: 20px;
            border-radius: 12px;
            border: 3px solid #FF5600;
            font-size: 18px;
            min-width: 300px;
            box-shadow: 0 8px 24px rgba(0,0,0,0.15);
        }
        
        .measurement-item {
            margin-bottom: 12px;
            display: flex;
            justify-content: space-between;
            align-items: center;
        }
        
        .measurement-value {
            font-weight: bold;
            color: #FF5600;
            font-size: 20px;
        }
        
        .measurement-title {
            font-size: 20px;
            font-weight: bold;
            color: #0C0302;
            margin-bottom: 15px;
            text-align: center;
            border-bottom: 2px solid #FF5600;
            padding-bottom: 8px;
        }
        
        .grid-toggle {
            margin-bottom: 15px;
        }
        
        .checkbox-container {
            display: flex;
            align-items: center;
            gap: 10px;
        }
        
        .checkbox {
            width: 20px;
            height: 20px;
            accent-color: #FF5600;
        }

        .footer {
            background: linear-gradient(to right);
            color: #0c0302;
            text-align: center;
            padding: 10px;
            margin-top: 15px;
            border-radius: 0 0 10px 10px;
        }
        
        .status-info {
            position: absolute;
            bottom: 20px;
            left: 20px;
            background: rgba(255, 255, 255, 0.9);
            padding: 15px;
            border-radius: 8px;
            border: 2px solid #38A169;
            font-size: 16px;
            font-weight: bold;
            color: #38A169;
        }
        
        .angle-measurement {
            border-top: 2px solid #ED8936;
            padding-top: 15px;
            margin-top: 15px;
        }
        
        .segment-measurement {
            border-top: 2px solid #2B6CB0;
            padding-top: 15px;
            margin-top: 15px;
        }