:root{--font-family: "Inter", system-ui, Avenir, Helvetica, Arial, sans-serif;--bg-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);--accent-color: #00d2ff;--button-hover: #3a7bd5;--glass-bg: rgba(255, 255, 255, .1);--glass-border: 1px solid rgba(255, 255, 255, .2);--glass-blur: blur(10px);--text-color: #ffffff;--error-color: #ff6b6b}body.theme-sunset{--bg-gradient: linear-gradient(135deg, #ff9966 0%, #ff5e62 100%);--accent-color: #ffd700;--button-hover: #ff4e50}body.theme-forest{--bg-gradient: linear-gradient(135deg, #134e5e 0%, #71b280 100%);--accent-color: #76c7c0;--button-hover: #2c3e50}body.theme-midnight{--bg-gradient: linear-gradient(135deg, #232526 0%, #414345 100%);--accent-color: #bdc3c7;--button-hover: #2c3e50}body{margin:0;display:flex;place-items:center;min-width:320px;min-height:100vh;font-family:var(--font-family);background:var(--bg-gradient);color:var(--text-color);overflow-x:hidden;transition:background .5s ease}#root{width:100%;display:flex;justify-content:center}.glass-panel{background:var(--glass-bg);backdrop-filter:var(--glass-blur);-webkit-backdrop-filter:var(--glass-blur);border:var(--glass-border);border-radius:16px;padding:2rem;box-shadow:0 4px 30px #0000001a}h1{font-size:2.5rem;font-weight:700;margin-bottom:1.5rem;text-align:center;text-shadow:0 2px 4px rgba(0,0,0,.2)}button,input{font-family:inherit;border:none;outline:none}input[type=range]{-webkit-appearance:none;appearance:none;width:100%;background:transparent}input[type=range]::-webkit-slider-thumb{-webkit-appearance:none;height:20px;width:20px;border-radius:50%;background:var(--accent-color);cursor:pointer;margin-top:-8px;box-shadow:0 0 10px var(--accent-color)}input[type=range]::-webkit-slider-runnable-track{width:100%;height:4px;cursor:pointer;background:#ffffff4d;border-radius:2px}