*{
    padding: 0px;
    margin: 0px;
    box-sizing: border-box;
    font-family: 'Ubuntu', sans-serif;  
}
html{
    overflow-x: hidden;   
}
body{
    background: #636e72;
    /* background: #2d3436; */
    background-clip: content-box;
}
#heading{
    padding-left: 10%;
    font-size: 60px;
    color: aliceblue;
    margin-top: -220px;
    cursor: help;
    text-shadow: 3px 3px #0984e3;
    transition: color 1s;
}
#heading:hover{
    color:#d63031;
}
#slogan{
    padding-left: 25%;
    font-family: 'Dancing Script', cursive;
    font-size: 40px;
    color: #dfe6e9;
    margin-bottom: 15%;
    transition: color 1s;
    cursor: help;
    text-shadow: 1px 1px #74b9ff;
}
#slogan:hover{
    color: #fdcb6e;
}
.container{
    width: 1000px;
    margin: 0px auto;
    -moz-margin: 0px auto;
    -webkit-margin: 0px auto;
    -ms-margin: 0px auto;
    background: #2d3436;
    /* background: #dfe6e9; */
    height: 100%;
    padding: 20px 20px;
    border-radius: 20px;
    /* background */
}
.cover{
    width: 100%;
    position: relative;
    top: 0px;
    left: 0px;
}
#wallpaper{
    width: 126%;
    height: 400px;
    margin-left: -14%;
    margin-right: -13%;
    margin-top: -10%;
    /* position: fixed;
    top: 0px;
    left: 0px; */
}
nav ul li {
    display: inline-block;
}
nav{
    position: sticky;
    top: 0;
    left: 0;
    z-index: 9;
    /* padding: 50px 0;
    min-width: 500px;  */
}
nav ul{
    position: sticky;
    margin-left: 10%;
    background: linear-gradient(90deg, 
     rgba(255, 255, 255, 0) 0%, 
     rgba(255, 255, 255, 0.5) 25%, 
     rgba(255, 255, 255, 0.5) 75%, 
     rgba(255, 255, 255, 0) 100%);
}
nav ul li a {
    padding: 10px; 
    color: #FFFFFF;
    font-size: 18px;
    font-family: Arial;
    text-decoration: none;
    display: block;
    transition: color 100ms linear;
 }
 nav ul li a:hover{
     color: #d63031;
 }
.content{
    width: 75%;
    position: relative;
    float: left;
    /* border: 3px solid red; */
}
h2{
    color: #dfe6e9;
    text-decoration: none;
    margin-bottom: 10px;
    /* margin: 0px auto; */
}
hr{
    border: 1px dashed #b2bec3;
}
#introduce{
    font-family: 'Dancing Script', cursive;
    color: #b2bec3;
    font-size: 20px;
    word-wrap: break-word;
    transition: color 500ms ease-in;
    padding-right: 20px;
    margin-bottom: 15px;
}
#introduce:hover{
    color: #ffeaa7;
}
span{
    font-family: 'Dancing Script', cursive;
    font-weight: 10px;
    font-size: 30px;
}
.form{
    width: 25%;
    /* height: 100px; */
    /* background: #dfe6e9; */
    position: relative;
    float: left;
}
.clearfix{
    content: "";
    display: table;
    clear: both;
}
.contact{
    /* height: 100px; */
    width: 1000px;
    margin: 0px auto;
    color: #dfe6e9;
    background: #636e72;
    font-family: 'Pacifico', cursive;
    /* font-family: 'Dancing Script', cursive; */
    padding: 20px 0px;
}
#avatar{
    width: 80px;
    position: fixed;
    bottom: 10px;
    right: 10px;
    border-radius: 50%;
    opacity: 1;
    transition: opacity 200ms linear;
}
#avatar:hover{
    opacity: 0.5;
}
input, textarea{
    width: 220px;
    padding-left: 5px;
    padding-top: 5px;
    padding-bottom: 5px;
    margin-bottom: 10px;
    border-radius: 10px;
}
.submit{
    background: #6c5ce7;
    transition: background 500ms linear;
}
.submit:hover{
    background: #ff7675;
}
table {
    width: 99%;
    font-size: 10pt;
}
table, th, td {
    border: 2px solid #cecece;
    border-collapse: collapse;
    text-align: center;
    table-layout: fixed;
    font-family: 'Dancing Script', cursive;
    color: #dfe6e9;
    padding-top: 5px;
    padding-bottom: 5px;
}
th{
    background: #b2bec3;
    color: #000;
    font-size:14px;
}
.time-day{
    background: #d63031;
}
.day-of-week{
    width: 50px;
    background: #ffeaa7;
    color: #000;
    font-size: 15px;
}
.clazz{
    width: 200px;
    font-size: 14px;
    text-align: start;
    padding-left: 10px;
}
#main-avt{
    width: 150px;
    height: 150px;
    position: absolute;
    top: 280px;
    left: 45%;
    border: 5px solid #ffffff;
    border-radius: 50%;
    transition: border 100ms linear;
}
#main-avt:hover{
    border: 5px dashed #74b9ff;
}
#face{
    width: 400px;
    height: 400px;
    position: absolute;
    top: 0;
    left: 800px;
    /* border: 5px solid #ffffff;
    border-radius: 50%; */
    margin-top: -45px;
    margin-right: 10px;
}

/*Danh sách 1 vài project trên github*/
.github{
    padding: 10px;
    width: 100%;
    height: 100px;
    position: relative;
}
.reponsitory{
    width: 100%;
    height: 30px;
    /* background: #000; */
    position: relative;
    float: left;
    margin: 10px;
    display: block;
    margin-bottom: 20px;
}
.thumbnail{
    width: 20%;
    /* height: 50px; */
    border: 1px solid black;
    border-radius: 50%;
    position: relative;
    float: left;
    margin-right: 10px;
}
a{
    text-decoration: none;
}
h3{
    width: 80%;
    font-size: 14px;
    color: #ffffff;
    /* padding: 5px; */
    margin-top: 5px;

    /* position: relative;
    float: left; */
}
.videos{
    background: #b2bec3;
    height: 530px;
    width: 100%;
    padding:20px;
    position: relative;
    /* margin-right: 5px;
    padding-right: 10px; */
    border-radius: 20px;
}
.vid{
    width: 30%;
    height: 170px;
    margin-right: 1.5%;
    margin-left: 1.5%;
    /* background: #ffffff; */
    position: relative;
    float: left;
}
.vid .frame{
    width: 100%;
    /* height: 100%; */
    border: 5px solid #fab1a0;
}
#timer{
    position: fixed;
    bottom: 15px;
    left: 20px;
    font-size: 24px;
    font-family: Arial, Helvetica, sans-serif;
    color: #00e732;
    font-weight: bold;
    padding: 10px;
    background: rgba(136, 38, 13, 0.3);
    border-radius: 40%;
}