我创建了一个侧边栏,当用户向下滚动时,我只是试图让它在标题下大约15px.我最初使用的是JS,但它确实使我的页面速度陷入困境,而且事情变得不稳定.我发现粘贴位置应该适用于大多数浏览器,但是我的侧边栏并没有坚持滚动.

我已经在各个地方阅读,以确保没有高度设置和任何类型的溢出到父元素,它不是.所以我正在努力找到问题的原因.我想知道是否有其他因素我没有在网上找到可能对位置产生影响的因素：粘性

.btn.sidebar {
  backface-visibility: hidden;
  Box-shadow: 0 0 1px rgba(0,0);
  display: inline-block;
  position: relative;
  vertical-align: middle;
  width: 100%;
  background: rgba(255,255,.6);
  border-radius: 0;
  font-size: 22px;
  transition: ease .5s;
}

.btn.sidebar:hover {
  background: #97B2AC;
  color: #fff;
}

p.contact-text {
  color: #eee;
  text-align: center;
}

div.modal-form-sidebar {
  position: sticky;
  position: -webkit-sticky;
  top: 0px;
  font: 95% Arial,Helvetica,sans-serif;
  width: 320px;
  padding: 16px;
  background: #5d84a1;
}

.modal-form-sidebar h1 {
  background: rgba(255,.4);
  padding: 13px 0;
  font-size: 140%;
  font-weight: 300;
  text-align: center;
  color: #fff;
  margin: 0;
}

.modal-form-sidebar input[type="text"],.modal-form-sidebar input[type="date"],.modal-form-sidebar input[type="datetime"],.modal-form-sidebar input[type="email"],.modal-form-sidebar input[type="number"],.modal-form-sidebar input[type="search"],.modal-form-sidebar input[type="time"],.modal-form-sidebar input[type="url"],.modal-form-sidebar textarea,.modal-form-sidebar select {
  -webkit-transition: all 0.30s ease-in-out;
  -moz-transition: all 0.30s ease-in-out;
  -ms-transition: all 0.30s ease-in-out;
  -o-transition: all 0.30s ease-in-out;
  outline: none;
  Box-sizing: border-Box;
  -webkit-Box-sizing: border-Box;
  -moz-Box-sizing: border-Box;
  width: 100%;
  background: #fff;
  margin-bottom: 4%;
  border: 1px solid #ccc;
  padding: 3%;
  color: #555;
  font: 95% Arial,sans-serif;
}

.modal-form-sidebar input[type="text"]:focus,.modal-form-sidebar input[type="date"]:focus,.modal-form-sidebar input[type="datetime"]:focus,.modal-form-sidebar input[type="email"]:focus,.modal-form-sidebar input[type="number"]:focus,.modal-form-sidebar input[type="search"]:focus,.modal-form-sidebar input[type="time"]:focus,.modal-form-sidebar input[type="url"]:focus,.modal-form-sidebar textarea:focus,.modal-form-sidebar select:focus {
  Box-shadow: 0 0 5px #5d84a1;
  padding: 3%;
  border: 1px solid #5d84a1;
}

.modal-form-sidebar input[type="submit"],.modal-form-sidebar input[type="button"] {
  Box-sizing: border-Box;
  -webkit-Box-sizing: border-Box;
  -moz-Box-sizing: border-Box;
  width: 100%;
  padding: 3%;
  background: #5d84a1;
  border-bottom: 2px solid #374F60;
  border-top-style: none;
  border-right-style: none;
  border-left-style: none;
  color: #fff;
}

.modal-form-sidebar input[type="submit"]:hover,.modal-form-sidebar input[type="button"]:hover {
  background: #7d9cb3;
}