/* 預設 960px */
.container-960 .container { max-width: 960px; }
.container-1200 .container { max-width: 1200px; }
/* 響應式 */
@media (max-width: 768px) {
    .container { max-width: 100%; padding: 0 15px; }
}
/* 美化按鈕、表單、卡片等 */
body { background: #f8f9fa; }
.card { border-radius: 15px; box-shadow: 0 4px 12px rgba(0,0,0,0.1); }
.btn-primary { background: #007bff; border: none; }