JSFiddle - React, Tailwind, and code Playground

HTML

<body>
  <h1 style="text-align: center;">自學網頁の嬰兒教材：第5課 ── 用力送出表單</h1>

  <h1>後台管理</h1>
  <h2>新增產品</h2>
  <form action="/add-product" method="post" target="_self">
    <div class="product">
      <label for="product">產品名稱</label>
      <input type="text" name="product" id="product" placeholder="請輸入產品名稱" required>
    </div>

    <div class="price">
      <label for="price">價格</label>
      <input type="text" name="price" id="price" placeholder="請輸入價格" required>
    </div>

    <div class="outfit">
      <label for="outfit">類別</label>
      <select name="outfit" id="outfit" required>
        <option value="" disabled selected>請選擇衣物類別</option>
        <option value="top">上衣</option>
        <option value="coat">外套</option>
        <option value="bottom">下身</option>
        <option value="accessories">配件</option>
      </select>
    </div>

    <div class="gender">
      <label for="">性別</label>
      <div class="gender-radio">
        <input type="radio" name="gender" id="male" value="male" required>
        <label for="male">男</label>
        <input type="radio" name="gender" id="female" value="female" required>
        <label for="female">女</label>
      </div>
    </div>

    <div class="delivery">
      <label for="delivery">是否免運費</label>
      <input type="checkbox" name="delivery" id="delivery">
    </div>

    <div class="note">
      <label for="note">備註</label>
      <textarea name="note" id="note" cols="30" rows="10" placeholder="請輸入備註"></textarea>
    </div>

    <div class="submit">
      <input type="submit" value="送出">
    </div>
  </form>
</body>

CSS

body {
  text-align: center;
  background-color: #eee;
}

form {
  background-color: #fff;
  width: 600px;
  margin: auto;
  padding: 50px;
  box-sizing: border-box;
  border-radius: 20px;
}

form div {
  margin: 20px 0;
  padding: 0 100px;
  text-align: left;
  font-size: 0;
}

form div * {
  vertical-align: middle;
}

form div label {
  display: inline-block;
  width: 100px;
  text-align: center;
  font-size: 16px;
}

form .product input,
form .price input,
form .outfit select {
  width: calc(100% - 100px);
  box-sizing: border-box;
}

form .gender {
  font-size: 0;
}

form .gender .gender-radio {
  display: inline-block;
  padding: 0;
  margin: 0;
  width: calc(100% - 100px);
  text-align: center;
}

/* option radio樣式及動畫 */
form .gender .gender-radio label {
  display: inline-block;
  width: 60px;
  cursor: pointer;
}

form .gender .gender-radio input {
  display: inline-block;
  margin: 0;
  width: 16px;
  height: 16px;
  vertical-align: middle;
  /* 不使用瀏覽器預設radio樣式 */
  appearance: none;
  border: 2px solid #aaa;
  border-radius: 50%;
  cursor: pointer;
}

form .gender .gender-radio input[type="radio"]:hover {
  background-color: #ccc;
  transition: 0.3s;
}

form .gender .gender-radio input[type="radio"]:checked {
  background-color: #fff;
  border-radius: 50%;
  border: 5px solid #432b9b;
  transition: border-color 0.3s;
}

form .delivery {
  text-align: center;
  font-size: 14px;
}

/* option checkbox樣式及動畫 */
form .delivery input[type="checkbox"] {
  width: 16px;
  height: 16px;
  /* 不使用瀏覽器預設checkbox樣式 */
  appearance: none;
  border: 2px solid #aaa;
  border-radius: 2px;
  background-color: #fff;
  transition: 0.5s;
  cursor: pointer;
  position: relative;
}

form .delivery input[type="checkbox"]:hover {
  background-color: #ccc;
  transition: 0.3s;
}

form .delivery input[type="checkbox"]:checked {
  border-color: #432b9b;
}

form .delivery input[type="checkbox"]::after {
  position: absolute;
  left: 5px;
  bottom: 1px;
  width: 5px;
  height: 15px;
 ...