sermon/main.css

* {
    box-sizing: border-box;
}

html {
    color: #fff;
    background-color: #111;
    font-family: Courier, Verdana, serif;
    font-size: 14px;
}

body {
    margin: 0;
}

.chat {
    width: 100%;
    padding: 30px 30px 80px 30px;
    position: relative;
    overflow: auto;
}

.message {
    width: 100%;
    margin-bottom: 40px;
}

.message__info {
    width: 100%;
    margin-bottom: 5px;
    line-height: 1;
    display: flex;
    align-items: flex-end;
}

.message__info-name {
    font-weight: 700;
    margin-right: 15px;
    font-size: 18px;
    line-height: .8;
}

.message__text {
    position: relative;
    white-space: pre-line;
}

.message__text p {
    margin: 0;
}

.message__text img {
    margin: 10px 0 0 0;
    width: 100%;
    max-width: 320px;
    display: block;
    height: auto;
}

.form {
    left: 15px;
    bottom: 15px;
    width: calc(100% - 30px);
    height: 60px;
    background-color: #fff;
    position: fixed;
    display: flex;
}

.form__input-message {
    padding: 20px;
    width: calc(100% - 60px);
    height: 100%;
    border: 0;
    outline: 0;
    margin: 0;
    font-size: 16px;
    resize: none;
    white-space: pre-line;
}

.form__input-submit {
    right: 0;
    top: 0;
    width: 60px;
    height: 60px;
    font-size: 30px;
    font-weight: 700;
    outline: 0;
    border: 0;
    cursor: pointer;
    position: absolute;
    background: none;
}

.modal {
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    z-index: 100;
    background-color: #000;
    position: fixed;
}

.modal__form {
    width: 100%;
    max-width: 600px;
    height: 60px;
    margin: 50px auto;
    position: relative;
    padding: 0 .5rem;
}

.modal__form-input {
    padding: 0 90px 0 30px;
    width: 100%;
    height: 100%;
    border: 0;
    outline: 0;
    font-size: 16px;
}

.modal__form-submit {
    right: 0;
    top: 0;
    width: 60px;
    height: 60px;
    font-size: 30px;
    font-weight: 700;
    outline: 0;
    border: 0;
    cursor: pointer;
    position: absolute;
    background: none;
}

.modal__info_url {
    text-align: center;
    visibility: hidden;
}

.modal__info_url a {
    color: white;
}

@media (max-width: 640px) {
    .chat {
        padding: 10px 10px 50px 10px;
    }

    .form {
        left: 10px;
        bottom: 10px;
        width: calc(100% - 20px);
    }

    .message {
        margin-bottom: 25px;
    }
}

.observer .chat {
    padding: 30px;
}

.observer .form {
    visibility: hidden;
}

.observer .message:last-child {
    margin-bottom: 0;
}