* {
    margin: 0;
    padding: 0;
    outline: none;
    font-family: Arial, Helvetica, sans-serif;
}

body,
html {
    min-width: 1024px;

}

a {
    text-decoration: none;
    color: #222;
}

.clear {
    clear: both;
    line-height: 0;
}

/* căn giữa section, và set độ rộng lớn nhất là 1200px */
section {
    max-width: 1205px;
    margin: 0 auto;
}

hr {
    color: #ddd;
    background-color: #ddd;
    border-top: 1px solid #ddd;
}

.flexContain {
    display: -webkit-box;
    display: -ms-flexbox;
    display: flex;
    -ms-flex-wrap: wrap;
    flex-wrap: wrap;
    -webkit-box-orient: horizontal;
    -webkit-box-direction: normal;
    -ms-flex-direction: row;
    flex-direction: row;
    -webkit-box-pack: center;
    -ms-flex-pack: center;
    justify-content: center;
}

/* Use for auto clear float */
/* ====== https://css-tricks.com/snippets/css/clear-fix/ ======== */
.group:before,
.group:after {
    content: "";
    display: table;
}

.group:after {
    clear: both;
}

.group {
    zoom: 1;
    /* For IE 6/7 (trigger hasLayout) */
}

/* =========   Alert ===============*/
#alert {
    z-index: 200; /* luôn trên cùng (đè lên những thứ khác) */
    display: block;
    position: fixed;
    bottom: 40px;
    right: 5px;
    padding: 20px;
    background-color: #111;
    opacity: 0;
    color: white;
    font-weight: bold;
    -webkit-transition: 0.3s;
    -o-transition: 0.3s;
    transition: 0.3s;
}

#closebtn {
    margin-left: 15px;
    color: white;
    font-weight: bold;
    float: right;
    font-size: 22px;
    line-height: 20px;
    -webkit-transition: 0.3s;
    -o-transition: 0.3s;
    transition: 0.3s;
}

/* ===== End clear float ====== */

#goto-top-page {
    position: fixed;
    bottom: 15px;
    right: 15px;
    z-index: 100;
    background: rgba(0, 0, 0, .2);
    color: #fff;
    font-size: 18px;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    line-height: 40px;
    text-align: center;
    cursor: pointer;
    transition-duration: .2s;
}
#goto-top-page:hover {
    background: rgba(0, 0, 0, .7);
    width: 50px;
    height: 50px;
    line-height: 50px;
}

/* ========= ScrollBar ============ */
::-webkit-scrollbar {
    width: .7em;
    height: .7em;
}

::-webkit-scrollbar-track {
    background: #eee;
}

::-webkit-scrollbar-thumb {
    background: #999;
}

::-webkit-scrollbar-thumb:hover {
    background: #bbb;
}

/* ==================== css thêm , chưa sử dụng ========================= */
/* tooltip https://www.w3schools.com/howto/tryit.asp?filename=tryhow_js_copy_clipboard2 */
.tooltip {
    position: absolute;
    display: inline-block;
    bottom: 5px;
    right: 5px;
}

.tooltip .tooltiptext {
    visibility: hidden;
    width: 140px;
    background-color: #555;
    color: #fff;
    text-align: center;
    border-radius: 6px;
    padding: 5px;
    position: absolute;
    z-index: 21;
    bottom: 150%;
    left: 50%;
    margin-left: -75px;
    opacity: 0;
    transition: opacity 0.3s;
}

.tooltip .tooltiptext::after {
    content: "";
    position: absolute;
    top: 100%;
    left: 50%;
    margin-left: -5px;
    border-width: 5px;
    border-style: solid;
    border-color: #555 transparent transparent transparent;
}

.tooltip:hover .tooltiptext {
    visibility: visible;
    opacity: 1;
}

/* animation ping from thegioididong */
.dot {
    width: 10px;
    height: 10px;
    background-color: #f33;
    border-radius: 100%;
    display: block;
}

.dot .ping {
    border: 1px solid #f33;
    width: 10px;
    height: 10px;
    opacity: 1;
    background-color: rgba(238, 46, 36, .2);
    border-radius: 100%;
    -webkit-animation-duration: 1.25s;
    animation-duration: 1.25s;
    -webkit-animation-name: sonar;
    animation-name: sonar;
    -webkit-animation-iteration-count: infinite;
    animation-iteration-count: infinite;
    -webkit-animation-timing-function: linear;
    animation-timing-function: linear;
    display: block;
    margin: -1px 0 0 -1px;
}

@keyframes sonar {
    0% {
        opacity: 1;
        -webkit-transform: scale(1);
        transform: scale(1)
    }

    100% {
        -webkit-transform: scale(3);
        transform: scale(3);
        opacity: 0
    }
}