body { background-color: #f0f2f5; font-family: 'Poppins', sans-serif; margin: 0; padding: 0; }
.container { padding: 80px 15px; }
.card { border: none; border-radius: 16px; box-shadow: 0 10px 30px rgba(0,0,0,0.1); background-color: #ffffff; overflow: hidden; }
.card-header { background-color: #0069d9; color: #ffffff; text-align: center; padding: 40px 20px; }
.card-title { font-size: 2rem; font-weight: 600; margin-bottom: 0; }
.form-label { font-weight: 500; color: #333333; }
.form-control, .form-select { border-radius: 8px; height: 50px; }
.btn-primary { background-color: #0069d9; border: none; border-radius: 8px; padding: 14px 20px; font-weight: 600; font-size: 1rem; transition: background-color 0.3s ease; }
.btn-primary:hover { background-color: #0053ba; }
.result-card { background-color: #ffffff; border: none; border-radius: 8px; padding: 15px; margin-top: 20px; box-shadow: 0 5px 15px rgba(0,0,0,0.1); display: flex; flex-direction: column; gap: 10px; position: relative; }
.copy-btn { cursor: pointer; position: absolute; top: 15px; right: 15px; font-size: 1.5rem; color: #0069d9; transition: color 0.3s ease; }
.copy-btn:hover { color: #0053ba; }
#cardNumbers { white-space: pre-wrap; word-break: break-all; font-family: monospace; }