body{font-family:Arial,sans-serif;background:#f4f4f4;margin:0;padding:0}.container{max-width:700px;margin:auto;background:white;padding:20px;border-radius:10px}.container.dark{background:#222;color:#fff}header{display:flex;justify-content:space-between;align-items:center}.expense-form{display:flex;gap:10px;margin-bottom:20px}.expense-form input,.expense-form select,.expense-form button{padding:8px}.expense-list ul{list-style:none;padding:0}.chart-container{text-align:center}.filters{margin:10px 0}