需求   实现一个输入框显示文本的字数，并且设置字数限制，当文本中没有内容或字符串长度超出限制，则不能点击确定按钮。

<div class="input-content">
    <div class="pt-2 rounded-tl-xl rounded-tr-xl bg-blue-100">
        <div class="px-4 pb-2 flex justify-between h-8 items-center">
            <span class="text-gray-800 font-semibold text-sm">请输入文本</span>
        </div>
        <div class="h-2 rounded-tl-xl rounded-tr-xl bg-white"></div>
    </div>
    <div class="px-4 pb-11">
        <textarea id="text-input" v-model="text" placeholder="请输入文本，建议使用简短的陈述句。" 
        class="input-textarea"></textarea>
        <div class="absolute inset-x-0 bottom-0 flex items-center justify-between mx-4 mt-2 mb-2">
            <div id="char-count" class="px-2.5 py-px text-xs leading-5 
            rounded-md inline-flex items-center flex-shrink-0 text-gray-800 bg-gray-100 
            !text-gray-500 opacity-50">0<span class="text-gray-300 mx-0.5">/</span>200
            </div>
            <el-button size="medium" type="primary" :disabled="!canClick" 
            :loading="testLoading" round @click="handleTest">确定</el-button>
        </div>
    </div>
</div>

computed: {
    canClick() {
        return this.text.length > 0 && this.text.length <= 200;
    },
}
data() {
    return {
        testLoading: false,
        text: '',
    }
}
mounted() {
    const textarea = document.getElementById('text-input');
    const charCount = document.getElementById('char-count');

    textarea.addEventListener('input', function () {
        const text = textarea.value;
        const count = text.length;
        
        charCount.textContent = count + '/200';
        if (count > 200) {
            textarea.value = text.slice(0, 200); // 截断输入文本，只保留前200个字符
            charCount.style.color = 'red'; // 如果超过200个字符，可以显示为红色提示
        } else {
            charCount.style.color = ''; // 恢复默认颜色
        }
    });
},

.input-content {
    position: relative;
    border-radius: 0.75rem;
    border-width: 1px;
    --tw-border-opacity: 1;
    border-color: rgb(28 100 242 / var(--tw-border-opacity));
}

.input-textarea {
    height: 220px !important;
    width: 100% !important;
    resize: none !important;
    border-style: none !important;
    font-size: .875rem !important;
    line-height: 1.25rem !important;
    font-weight: 400 !important;
    --tw-text-opacity: 1 !important;
    color: rgb(55 65 81/ 1) !important;
    caret-color: #1c64f2 !important;
    outline: none;
}