.header {
  width: 100%;
  max-width: 100%;
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 16px;
  box-sizing: border-box;
  overflow-x: hidden; /* 🔴 shake fix */
}

.search-input {
  flex: 1;
  min-width: 0; /* 🔴 VERY IMPORTANT */
  padding: 10px 12px;
  border: 1px solid #e5e7eb;
  border-radius: 6px;
  outline: none;
}

.customer-select {
  width: 180px;
  padding: 10px;
  border: 1px solid #e5e7eb;
  border-radius: 6px;
}

/* 📱 Mobile fix */
@media (max-width: 768px) {
  .header {
    flex-direction: column;
    align-items: stretch;
  }

  .customer-select {
    width: 100%;
  }
}