:root{--background-color: #ffffff;--text-color: #000000;--primary-color: #007bff;--secondary-color: #6c757d;--border-color: #dee2e6}body.dark-theme{--background-color: #121212;--text-color: black;--primary-color: #1a73e8;--secondary-color: #b0bec5;--border-color: #37474f}body.dark-theme h1,body.dark-theme button{color:#fff!important}body.dark-theme input{color:#fff}body{margin:0;background-color:var(--background-color);color:var(--text-color);transition:background-color .3s,color .3s}h1{margin-left:1rem;margin-right:1rem}