function detectOS() { const platform = navigator.platform.toLowerCase(), iosPlatforms = ['iphone', 'ipad', 'ipod', 'ipod touch']; if (platform.includes('mac')) return 'MacOS'; if (iosPlatforms.includes(platform)) return 'iOS'; if (platform.includes('win')) return 'Windows'; if (/android/.test(navigator.userAgent.toLowerCase())) return 'Android'; if (/linux/.test(platform)) return 'Linux'; return 'unknown'; }