rder-box;
        }

        body {
            font-family: 'Microsoft YaHei', Arial, sans-serif;
            background: linear-gradient(135deg, #1e3c72 0%, #2a5298 100%);
            overflow: hidden;
            height: 100vh;
            color: white;
        }

        .presentation-container {
            position: relative;
            width: 100vw;
            height: 100vh;
            display: flex;
            justify-content: center;
            align-items: center;
            background: radi