Pada kesempatan kali ini saya akan membagikan sebuah snippet Pure CSS3 Info Box yang belakangan ini ada yang meminta, dan saya selaku admin blog ini ingin menyampaikan sesuatu :

"Mohon maaf belakangan ini, blog ini sudah jarang diupdate, dikarenakan kesibukan didunia nyata dan saya akan berencana mengganti layout blog ini sepenuhnya tidak akan lama lagi dikarenakan load yang terlalu lama dan saya akan menyatakan ini adalah postingan vakum saya"
Regards - Rizky

Oke, langsung saja ke cara pemasangannya:

HTML

<div class="alert alert-success alert-white rounded">
    <button type="button" class="close" data-dismiss="alert" aria-hidden="true">×</button>
    <div class="icon"><i class="fa fa-check"></i></div>
    <strong>Success!</strong> Changes has been saved successfully!
</div>
<div class="alert alert-info alert-white rounded">
    <button type="button" class="close" data-dismiss="alert" aria-hidden="true">×</button>
    <div class="icon"><i class="fa fa-info-circle"></i></div>
    <strong>Info!</strong> You have 3 new messages in your inbox.
</div>
<div class="alert alert-warning alert-white rounded">
    <button type="button" class="close" data-dismiss="alert" aria-hidden="true">×</button>
    <div class="icon"><i class="fa fa-warning"></i></div>
    <strong>Alert!</strong> Don't forget to save your data.
</div>
<div class="alert alert-danger alert-white rounded">
    <button type="button" class="close" data-dismiss="alert" aria-hidden="true">×</button>
    <div class="icon"><i class="fa fa-times-circle"></i></div>
    <strong>Error!</strong> The server is not responding, try again later.
</div>

.close {
    float: right;
    font-size: 21px;
    font-weight: bold;
    line-height: 1;
    color: #000;
    text-shadow: 0 1px 0 #fff;
    opacity: .2;
    filter: alpha(opacity=20);
}

.close:hover,.close:focus {
    color: #000;
    text-decoration: none;
    cursor: pointer;
    opacity: .5;
    filter: alpha(opacity=50);
}

button.close {
    padding: 0;
    cursor: pointer;
    background: transparent;
    border: 0;
    -webkit-appearance: none;
}

.alert {
    padding: 15px;
    margin-bottom: 20px;
    border: 1px solid transparent;
    border-radius: 4px;
}

.alert h4 {
    margin-top: 0;
    color: inherit;
}

.alert .alert-link {
    font-weight: bold;
}

.alert>p,.alert>ul {
    margin-bottom: 0;
}

.alert>p+p {
    margin-top: 5px;
}

.alert-dismissable {
    padding-right: 35px;
}

.alert-dismissable .close {
    position: relative;
    top: -2px;
    right: -21px;
    color: inherit;
}

.alert-success {
    background-color: #dff0d8;
    border-color: #d6e9c6;
    color: #3c763d;
}

.alert-success hr {
    border-top-color: #c9e2b3;
}

.alert-success .alert-link {
    color: #2b542c;
}

.alert-info {
    background-color: #d9edf7;
    border-color: #bce8f1;
    color: #31708f;
}

.alert-info hr {
    border-top-color: #a6e1ec;
}

.alert-info .alert-link {
    color: #245269;
}

.alert-warning {
    background-color: #fcf8e3;
    border-color: #faebcc;
    color: #8a6d3b;
}

.alert-warning hr {
    border-top-color: #f7e1b5;
}

.alert-warning .alert-link {
    color: #66512c;
}

.alert-danger {
    background-color: #f2dede;
    border-color: #ebccd1;
    color: #a94442;
}

.alert-danger hr {
    border-top-color: #e4b9c0;
}

.alert-danger .alert-link {
    color: #843534;
}

.alert {
    border-radius: 0;
    -webkit-border-radius: 0;
    box-shadow: 0 1px 2px rgba(0,0,0,0.11);
}

.alert .sign {
    font-size: 20px;
    vertical-align: middle;
    margin-right: 5px;
    text-align: center;
    width: 25px;
    display: inline-block;
}

.alert-success {
    background-color: #dbf6d3;
    border-color: #aed4a5;
    color: #569745;
}

.alert-info {
    background-color: #d9edf7;
    border-color: #98cce6;
    color: #3a87ad;
}

.alert-warning {
    background-color: #fcf8e3;
    border-color: #f1daab;
    color: #c09853;
}

.alert-danger {
    background-color: #f2dede;
    border-color: #e0b1b8;
    color: #b94a48;
}

.alert-white {
    background-image: linear-gradient(to bottom,#FFFFFF,#F9F9F9);
    border-top-color: #d8d8d8;
    border-bottom-color: #bdbdbd;
    border-left-color: #cacaca;
    border-right-color: #cacaca;
    color: #404040;
    padding-left: 61px;
    position: relative;
}

.alert-white .icon {
    text-align: center;
    width: 45px;
    height: 100%;
    position: absolute;
    top: -1px;
    left: -1px;
    border: 1px solid #bdbdbd;
}

.alert-white .icon:after {
    -webkit-transform: rotate(45deg);
    -moz-transform: rotate(45deg);
    -ms-transform: rotate(45deg);
    -o-transform: rotate(45deg);
    -webkit-transform: rotate(45deg);
    display: block;
    content: '';
    width: 10px;
    height: 10px;
    border: 1px solid #bdbdbd;
    position: absolute;
    border-left: 0;
    border-bottom: 0;
    top: 50%;
    right: -6px;
    margin-top: -5px;
    background: #fff;
}

.alert-white.rounded {
    border-radius: 3px;
    -webkit-border-radius: 3px;
}

.alert-white.rounded .icon {
    border-radius: 3px 0 0 3px;
    -webkit-border-radius: 3px 0 0 3px;
}

.alert-white .icon i {
    font-size: 20px;
    color: #FFF;
    left: 12px;
    margin-top: -10px;
    position: absolute;
    top: 50%;
}

.alert-white.alert-danger .icon,.alert-white.alert-danger .icon:after {
    border-color: #ca452e;
    background: #da4932;
}

.alert-white.alert-info .icon,.alert-white.alert-info .icon:after {
    border-color: #3a8ace;
    background: #4d90fd;
}

.alert-white.alert-warning .icon,.alert-white.alert-warning .icon:after {
    border-color: #d68000;
    background: #fc9700;
}

.alert-white.alert-success .icon,.alert-white.alert-success .icon:after {
    border-color: #54a754;
    background: #60c060;
}

Sekian tentang bagaimana cara pemasangan Pure CSS3 Info Box ini, semoga bermanfaat.