避免CSS布局中的区块重叠：正确使用HTML标签与Display属性

<sec-2 class="mmargin">
   <!-- ... sec-2 的内容 ... -->
</sec-2>
<div class="sec3 mmargin">
   <!-- ... sec3 的内容 ... -->
</div>

/* 应用于非标准标签 sec-2 */
sec-2 {
  width: var(--mobile-width);
  display: flex; /* 尽管设置了flex，但可能因标签非标准而行为异常 */
  flex-direction: column;
}

/* 应用于 div.sec3 */
.sec3 {
  width: var(--mobile-width); /* 原始代码中存在此属性 */
  background-color: hsl(238, 22%, 44%);
  display: flex; /* 原始代码中存在此属性 */
  flex-direction: column;
  justify-content: center;
  color: white;
  padding: 50px;
}

<!-- 将 <sec-2> 替换为 <div class="sec-2"> -->
<div class="mmargin sec-2">
   <div class="image">
   </div>
   <div class="text">
      <h2>Stay productive, wherever you are</h2>
      <p>
         Lorem ipsum dolor sit amet consectetur adipisicing elit. Temporibus
         doloribus ipsa cum. Sapiente quisquam error magnam odit repellendus
         nihil dolorem quis
      </p>
      <p>
         Lorem ipsum dolor sit amet consectetur adipisicing elit. Temporibus
         doloribus ipsa cum. Sapiente quisquam error magnam odit repellendus
         nihil dolorem quis
      </p>
      <p class="p">
         See how Fylo works 
      </p>
      <div class="card">
         <div class="image1">
         </div>
         <p>
            Lorem, ipsum dolor sit amet consectetur adipisicing elit. Qui omnis ducimus veniam, cupidita
         </p>
         <div class="av">
            <div class="image2">
            </div>
            <div class="txt">
               <h3>
                  Kyle Burton
               </h3>
               <p>
                  Founder & CEO, Huddle
               </p>
            </div>
         </div>
      </div>
   </div>
</div>
<!-- section 2  -->
<!-- section-3  -->
<div class="sec3 mmargin">
   <div class="text">
      <h2>
         Get early access today
      </h2>
      <p>
         Lorem ipsum dolor sit amet consectetur adipisicing elit. Aliquid sapiente a alias libero labore rerum assumenda cupiditate illum iure adipisci. Veniam vel voluptatem deleniti officia culpa sed, asperiores eveniet fugiat.
      </p>
   </div>
   <form action="">
      <input type="email" placeholder="[email protected]">
      <button>
      Get Started For Free
      </button>
   </form>
</div>

* {
  box-sizing: border-box;
}

:root {
  --mobile-width: 375px;
  --light-blue: hsl(224, 93%, 58%);
}

.mmargin {
  margin: 50px auto;
}

body {
  margin: 0;
  padding: 0 ;
  font-family: "Open Sans", sans-serif;
  font-weight: 400;
}

h1,
h2,
h3 {
  font-family: "Raleway", sans-serif;
  font-weight: 700;
}

button:hover {
  opacity: 0.5;
  cursor: pointer;
}

/* sec-2 样式更新为类选择器 */
.sec-2 {
  width: var(--mobile-width);
  display: flex; /* 保持 flex 布局 */
  flex-direction: column;
}

.sec-2 .image {
  margin-bottom: 50px;
}

.sec-2 .image img {
  max-width: 100%;
}

.sec-2 .text h2 {
  font-size: 20px;
  text-align: center;
  margin: 30px 0;
}

.sec-2 .text p.p {
  margin: 50px auto;
  text-align: center;
  color: #3da08f;
  position: relative;
}

.sec-2 .text p.p:hover {
  opacity: 0.5;
  cursor: pointer;
}

.sec-2 .text p.p::before {
  content: "";
  width: 175px;
  height: 2px;
  background-color: #3da08f;
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
  bottom: -5;
}

.sec-2 .text p.p img {
  width: 25px;
  vertical-align: middle;
}

.sec-2 .text .card {
  display: flex;
  flex-direction: column;
  box-shadow: 0 0 10px rgb(197, 197, 197);
  padding: 20px;
}

.sec-2 .text .card .image1 {
  width: 40px;
}

.sec-2 .text .card .image1 img {
  width: 50%;
}

.sec-2 .text .av {
  display: flex;
  align-items: center;
  gap: 15px;
  margin: 30px 0;
}

.sec-2 .text .av .image2 {
  width: 50px;
}

.sec-2 .text .av img {
  max-width: 100%;
  border-radius: 50%;
}

.sec-2 .text .txt {
  display: flex;
  flex-direction: column;
  gap: 5px;
}

.sec-2 .text .txt h3 {
  margin: 0;
}

.sec-2 .text .txt p {
  margin: 0;
}

/* .sec3 样式调整 */
.sec3 {
  background-color: hsl(238, 22%, 44%);
  display: block; /* 确保其作为块级元素独立渲染 */
  /* 原始的 width: var(--mobile-width); 在解决方案中被移除，这有助于其自然流动或由父容器控制宽度 */
  flex-direction: column; /* 如果需要内部flex布局，可保留 */
  justify-content: center;
  color: white;
  padding: 50px;
}

.sec3 .text h2 {
  text-align: center;
}

.sec3 .text p {
  text-align: center;
  font-size: 18px;
  line-height: 1.5;
}

.sec3 form {
  margin: 30px auto;
}

.sec3 form input {
  width: 50%;
  margin-bottom: 10px;
  opacity: 0.3;
}

.sec3 form button {
  width: 50%;
  text-align: center;
}