:root{--primary-color: #3498db;--secondary-color: #2980b9;--text-color: #333;--bg-color: #f5f5f5;--card-bg: #fff;--border-color: #ddd}.dark{--primary-color: #2c3e50;--secondary-color: #34495e;--text-color: #ecf0f1;--bg-color: #1a1a1a;--card-bg: #2d2d2d;--border-color: #444}body{font-family:Arial,sans-serif;margin:0;padding:0;background-color:var(--bg-color);color:var(--text-color);transition:background-color .3s,color .3s}.container{max-width:800px;margin:0 auto;padding:20px}.header{display:flex;justify-content:space-between;align-items:center;margin-bottom:30px}.theme-toggle{background-color:var(--primary-color);color:#fff;border:none;padding:8px 16px;border-radius:4px;cursor:pointer;transition:background-color .3s}.theme-toggle:hover{background-color:var(--secondary-color)}.task-form{background-color:var(--card-bg);padding:20px;border-radius:8px;box-shadow:0 2px 4px #0000001a;margin-bottom:20px}.form-group{margin-bottom:15px}.form-group label{display:block;margin-bottom:5px;font-weight:700}.form-group input{width:100%;padding:10px;border:1px solid var(--border-color);border-radius:4px;background-color:var(--card-bg);color:var(--text-color)}.btn{background-color:var(--primary-color);color:#fff;border:none;padding:10px 20px;border-radius:4px;cursor:pointer;transition:background-color .3s}.btn:hover{background-color:var(--secondary-color)}.task-list{list-style:none;padding:0}.task-item{background-color:var(--card-bg);padding:15px;margin-bottom:10px;border-radius:8px;box-shadow:0 2px 4px #0000001a;display:flex;justify-content:space-between;align-items:center}.task-content{flex-grow:1}.task-title{font-weight:700;margin-bottom:5px}.task-text{color:var(--text-color);opacity:.8}.delete-btn{background-color:#e74c3c;color:#fff;border:none;padding:5px 10px;border-radius:4px;cursor:pointer;transition:background-color .3s}.delete-btn:hover{background-color:#c0392b}