.coa-form-wrapper { max-width: 400px; margin: 20px auto; border: 1px solid #ccc; padding: 20px; }
.coa-tabs { display: flex; margin-bottom: 10px; }
.coa-tab { flex: 1; padding: 10px; background: #f0f0f0; border: 1px solid #ccc; cursor: pointer; }
.coa-tab.active { background: #0073aa; color: #fff; }
.coa-tab-content { display: none; }
.coa-tab-content.active { display: block; }
input, button { display: block; width: 100%; margin: 10px 0; padding: 10px; }