zulip/static/styles/alerts.css

/* general alert styling changes */
.alert {
    display: none;
}

.alert.show {
    display: block;
}

.alert#administration-status {
    margin: 20px;
}

/* alert box compoent changes */
.alert-box {
    position: absolute;
    top: 0px;
    left: 0px;
    width: 900px;
    margin-left: calc(50% - 450px);
    z-index: 102;

    -webkit-font-smoothing: antialiased;
}

.alert-box .alert.show {
    animation-name: fadeIn;
    animation-duration: 0.3s;
    animation-fill-mode: forwards;
}

.alert-box .alert.fade-out {
    animation-name: fadeOut;
    animation-duration: 0.3s;
    animation-fill-mode: forwards;
}

.alert-box .alert {
    font-size: 1rem;

    box-shadow: 0px 0px 30px rgba(220, 78, 78, 0.3);
    border-radius: 0px;
    border: none;
}

.alert-box .alert a {
    color: #90deff;
}

.alert-box .alert .faded {
    opacity: 0.7;
}

.alert-box .alert .restart_get_updates_button {
    color: #89dcff;
}

.alert-box .alert .restart_get_updates_button:hover {
    color: #89dcff;
}

.alert-box .alert.alert-error::before {
    position: absolute;
    top: 15px;
    left: 10px;

    font-family: "FontAwesome";
    font-size: 1.5em;
    content: "\f071";

    color: #fff;
}

.alert-box .alert.alert-error {
    position: relative;

    /* gives room for the error icon. */
    padding-left: 50px;
    padding-top: 15px;

    background-color: #bd6767;
    color: #fff;
    text-shadow: none;
}

.alert-box .alert .exit {
    position: absolute;
    top: 15px;
    right: 0px;

    font-size: 2.5em;
    font-weight: 300;

    cursor: pointer;
}

.alert-box .alert .exit::after {
    padding: 10px;
    content: "×";
}

/* animation section */
@keyframes fadeIn {
    0% {
        display: block;
        opacity: 0;
        transform: translateY(-100px);
    }

    100% {
        opacity: 1;
        transform: translateY(0px);
    }
}

@keyframes fadeOut {
    0% {
        opacity: 1;
        transform: translateY(0px);
    }

    100% {
        display: none;
        opacity: 0;
        transform: translateY(-100px);
    }
}

/* @media queries */
@media (max-width: 900px) {
    .alert-box {
        width: 80%;
        left: 10%;
        margin-left: 0px;
    }
}