Chat Application UI Code Snippet only for youtube video

/*
backhroundColor: #ffe290;
color: #4a5a6e;
you: #1f92ff;
message background color: #f1f3f8;
button color: #028aff;


*/

body {
  background: #ffe290;
  font-family: 'KoHo', sans-serif;
}

.bgColor{
  background: #ffe290;
}
.primaryColor{
  color: #4a5a6e;
}
.b-200{
  font-weight: 200;
}
.b-300{
  font-weight: 300;
}

.b-400{
  font-weight: 400;
}

.b-500{
  font-weight: 500;
}
.b-600{
  font-weight: 600;
}
.b-700{
  font-weight: 700;
}

.app-header{
  display: flex;
  justify-content: center;
  height: 150px;
  align-items: center;
}
.app-header img{
  height: 50px;
}
.app-header > .app-name{
  font-size: 30px;
  margin: 0 20px;
}

.chat-system{
  display: flex;
  justify-content: center;
  align-items: center;
}
.chat-box{
  width: 350px;
  background: #fff;
  border-radius: 10px;
  box-shadow: 0 0 2px 0px rgba(0, 0, 0, 0.3);
  overflow: hidden;
}

.username-container{
  display: flex;
  justify-content: center;
  align-items: center;
  box-sizing: border-box;
  padding: 20px;
}
.username-label{
  padding: 0;
  margin: 10px 0;
}
.input{
  border-radius: 5px;
  border: 1px solid #eee;
  outline: none;
  width: 200px;
  height: 25px;
  font-size: 14px;
  box-sizing: border-box;
  padding: 10px;
  color: #777;
  background: #eee;
}


.online-users-header{
  width: 100%;
  height: 30px;
  background: #028aff;
  color: #fff;
  font-weight: 500;
  font-size: 18px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.users-list{
  list-style: none;
  padding: 0px;
  margin: 0;
  max-height: 300px;
}

.users-list li{
  padding: 5px 10px;
  background: #eee;
  border-bottom: 1px solid rgba(0, 0, 0, 0.1);
  cursor: pointer;
  font-size: 14px;
  font-weight: 500;
  letter-spacing: 1px;
  display: flex;
  justify-content: space-between;
}

.users-list li .joined-date{
  font-size: 10px;
  display: inline-block;
  margin: 0 10px;
}

.users-list li:hover{
  background: rgb(177, 176, 176);
}

.message-area{
  height: 250px;
}

.message-control{
  display: flex;
}
.message-control textarea{
  width: 80%;
  border: none;
  background: #eee;
  resize: none;
  outline: none;
  font-family: 'KoHo', sans-serif;
  box-sizing: border-box;
  padding: 5px;
  display: inline-block;
}
.message-control button{
  display: flex;
  flex: 1;
  justify-content: flex-end;
  outline: none;
  border: none;
  font-family: 'KoHo', sans-serif;
  justify-content: center;
  align-items: center;
  font-weight: 500;
  cursor: pointer;
  background: #028aff;
  color: #fff;
}

.new-message-count{
  font-size: 10px;
  display: inline-block;
  background: #028aff;
  width: 15px;
  height: 15px;
  border-radius: 50%;
  text-align: center;
  color: #fff;
}

.message-area ul{
  padding: 0;
  margin: 0;
  height: 250px;
  overflow-y: scroll;
}
.message-area ul li{
  display: flex;
  align-items: flex-start;
  flex-wrap: wrap;
  margin: 10px;
}
.message-area ul .user-pic{
  width: 30px;
  height: 30px;
  background: #eee;
  border-radius: 50%;
  overflow: hidden;
}

.message-area ul .user-pic img{
  max-width: 100%;
  max-height: 100%;
  object-fit: contain;
}

.message-area ul .message-text{
  background: #028aff;
  border-radius: 5px;
  color: #fff;
  font-size: 13px;
  padding: 2px 5px;
  box-sizing: border-box;
  margin: 0 5px;
  max-width: 270px;
}

.file-input-container{
  position: relative;
}
.file-input-container input[type="file"]{
  position: absolute;
  width: 0;
  height: 0;
  opacity: 0;
}
.file-input-container label{
  display: block;
  color: #028aff;
  padding: 0 10px;
  cursor: pointer;
  background: #eee;
  height: 100%;
  display: flex;
  align-items: center;
}

.image-container{
  background: #eee;
  border: 1px solid rgba(0, 0, 0, 0.5);
  border-radius: 5px;
  margin: 0 5px;
}

.attachement-display{
  display: flex;
  align-items: center;
  box-sizing: border-box;
  padding: 5px 10px;
  background: #eee;
  border-bottom: 1px solid rgba(0, 0, 0, 0.2);
}
.attachment-name{
  font-weight: 600;
  font-size: 14px;
  display: inline-block;
  margin: 0 5px;
}
.remove-attachment{
  font-size: 20px;
  font-weight: 500;
  margin: 0 5px;
  cursor: pointer;
  color: rgba(0, 0, 0, 0.4);
}