:root {
    --background-primary: #5c52b962;
    --background-secondary: #fff;
    --message-box: whitesmoke;
    --border: lightgray;
}

body {
    background: linear-gradient(
        var(--background-primary),
        var(--background-secondary)
    );
    overflow: hidden;
}

.container {
    height: 100vh;
}

.message-box {
    border: 1px solid var(--border);
    background: var(--message-box);
    width: 500px;
    height: auto;
    padding: 0 20px;
    box-shadow: 0px 2px 4px 0px rgba(0, 0, 0, 0.5);
}

.message-box input {
    width: 90%;
    padding: 8px 0;
    border: 1px solid var(--border);
}