index.css

body {
         background-image: url(daa.jpg);
        background-repeat : no-repeat;
    margin: 0;
    font-family: sans-serif;
    color: white;
}

#band {
    width: 100%;
    height: 7px;
    background-color: rgb(4, 166, 255);
    margin-bottom: 50px;
}

section {
    background-color: rgb(4, 166, 255);
    width: 30%;
    padding: 20px;
    border-radius: 10px;
    box-shadow: 0 2px 5px 0 lightgrey;
    height: 100%;
}

h3, h2 {
    margin-top: 0;
    text-align: center;
}
textarea {
  height: 30px;
   border: 0;
    border-radius: 10px;
    padding: 10px;
    width: 40%;
    float:left;
}
input {
    border: 0;
    border-radius: 10px;
    padding: 10px;
    width: 40%;
    float: center;
   margin-bottom: 4px;
}

button {
    border: 0;
    border-radius: 10px;
    padding: 10px;
    cursor: pointer;
    color: white;
    background-color: rgb(0, 94, 145);
}

button:hover {
    opacity: 0.9;
}

button:active {
    background-color: rgb(0, 81, 125);
}

#sections {
    display: flex;
    justify-content: space-around;
}

#write-message {
    width: 80%;
}
.message-box {
    background-color: rgb(70, 190, 255);
    border-radius: 10px;
    margin: 10px 0;
    padding: 10px;
}