body {
    color: #082B48;
    font-family: Verdana, Geneva, Tahoma, sans-serif;
    line-height: 1.5;
}

img {
    width: 100%;
    height: auto;
}

a {
    text-decoration: none;
    color: #082B48;
}

a:hover {
    opacity: 0.7;
}

.container {
    width: 90%;
    max-width: 980px;
    margin:auto;
}

.clear::after {
    content:"";
    clear: both;
    display: block;
}

.header {
    margin-bottom: 20px;
}

.header-logo {
    float: left;
    width: 30%;
}

.header-right {
    float: right;

}

.header-nav-item {
    float: left;
    margin-left: 30px;
    font-size: 25px;
    line-height: 69.77px;
}


.top {
    background-image: url(../image/paint-brush-3207945_1920.jpg);
    background-size:cover;
    padding: 200px;
    margin-bottom: 20px;
}

.top-title {
    font-size: 35px;
    text-align: center;
}

.section-title {
    text-align: center;
    font-size: 25px;
    margin-bottom: 5px;
}

.section-sub-title {
    text-align: center;
    font-size: 15px;
    margin-bottom: 20px;
    color: lightgray;
}

.course-wrapper {
    display: flex;
    justify-content: space-between;

}

.course-item {
    width: 32%;
    padding: 10px 20px;
    border: solid;
    border-radius: 8px;
}

.course-title {
    font-size: 18px;
    margin-bottom: 10px;
    text-decoration: underline;
}

.course-about {
    font-size: 15px;
}

.about {
    padding: 40px;
    width: 65%;
    margin: auto;
}

.about-item {
    display: flex;
    justify-content: center;
}
.about-left {
    width: 40%;
    margin: auto;
}

.about-right {
    width: 58%;
}

.pic-myself {
    width: 70%;
    margin: auto;
}

.img-link {
    padding: 10px;
    display: flex;
    width: 20%;
    margin-left: 30px;
}

.img-link-item {
    margin-left: 10px;

}

.sub-title {
    font-size: 10px;
}

.myname {
    font-size: 25px;

}

.introduction {
    font-size: 13px;
    margin-bottom: 10px;
}

.direction-item {
    font-size: 13px;
}

.contact-logo {
    width: 40%;
    margin: auto;
    padding: 30px;
}
.contact-logo-left {
    float: left;
    width: 35%;
}

.contact-logo-right {
    float: right;
    width: 35%;
}

.tw-img {
    padding-bottom: 20px;
}

.address {
    font-size: 12px;
    color: blue;
}

.copyright {
    background-color: black;
    font-size: 8px;
    color: white;
    height: 40px;
    text-align: center;
    line-height: 40px;
}

@media only screen and (max-width: 767px) {

.clear::after{
    content:none
}

.header-logo {
    float: none;
    margin-top: 10px;
}

.header-right {
    float: none;
}

.header-nav {
    display: flex;
    justify-content: space-between;
}

.header-nav-item {
    float: none; 
    margin: 0;
}

.top {
    padding: 120px 0;
}
.top-title {
    font-size: 32px;
}

.section-title {
    font-size: 24px;
}

.about {
    width: 90%;
}

.about-item {
    flex-wrap: wrap;
}

.about-left {
    width: 100%;
    margin: 10px;
}

.pic-myself {
    width: 100%;
}

.img-link {
    width: 40%;
    margin-left: 10px;
}

.about-right {
    width: 100%;
}

.course-wrapper {
    flex-wrap: wrap;
}

.course-item {
    width: 90%;
    margin: auto;
    margin-bottom: 10px;
}

.contact-logo {
    width: 80%;
    padding: 0;
    top: 0;
    bottom: 0;
    left: 0;
    right: 0;
}

.contact-logo-left {
    float: none;
    margin: auto;

}

.mail-img {
    width: 100%;
    margin: auto;
}

.contact-logo-right {
    float: none;
    margin: auto;
    padding-top: 10px;
}

.tw-img {
    width: 100%;
    margin: auto;
    margin-top: 10px;
    padding: 10px;
}

.address {
    width: 100%;
    font-size: 10px;
    text-align: center;
    margin: auto;
}

}