* {
            padding: 0;
            margin: 0;
            box-sizing: border-box;
            font-family: Arial, Helvetica, sans-serif;
        }
        
        .main-content {
            width: 100%;
            height: 100px;
            display: flex;
            justify-content: center;
            align-items: center;
            font-size: 40px;
            color: gray;
        }
        
        footer {
            width: 100%;
            background-color: #26272b;
        }
        
        .sec-1 {
            display: flex;
            flex-direction: row;
            justify-content: space-between;
            padding: 30px 15px;
        }
        
        .about {
            width: 40%;
        }
        
        .sec-1 h2 {
            font-size: 18px;
            color: lightgray;
            text-transform: uppercase;
            margin-bottom: 10px;
        }
        
        .about p {
            text-align: justify;
            color: lightgray;
            line-height: 24px;
            margin-top: 10px;
        }
        
        .sec-1 ul {
            list-style-type: none;
            line-height: 24px;
        }
        
        .sec-1 ul li {
            list-style-type: none;
            line-height: 24px;
        }
        
        a {
            text-decoration: none;
            color: gray;
        }
        
        a:hover {
            color: orange;
        }
        
        span {
            color: gray;
        }
        
        i {
            color: gray;
            font-size: 20px;
        }
        
        .sec-2 {
            display: flex;
            justify-content: center;
            padding: 30px;
        }
        
        .sec-2 h2 {
            color: lightgray;
            font-size: 24px;
            padding: 0;
        }
        
        .sec-2 a {
            display: inline-block;
            padding: 10px 15px;
            color: white;
            font-size: 18px;
            background-color: red;
            margin-left: 10px;
            border-radius: 15px;
            -webkit-border-radius: 15px;
            -moz-border-radius: 15px;
            -ms-border-radius: 15px;
            -o-border-radius: 15px;
        }
        
        .sec-2 a:hover {
            background-color: orange;
        }
        
        .sec-3 {
            display: flex;
            justify-content: center;
            padding: 20px;
        }
        
        .sec-3 ul {
            list-style-type: none;
            margin: 20px;
        }
        
        .sec-3 ul li {
            display: inline-block;
            width: 60px;
            height: 60px;
            padding: 20px;
            background-color: #424242;
            border-radius: 50%;
            -webkit-border-radius: 50%;
            -moz-border-radius: 50%;
            -ms-border-radius: 50%;
            -o-border-radius: 50%;
            margin-right: 20px;
        }
        
        .sec-3 ul li i {
            color: white;
            font-size: 24px;
            line-height: 20px;
            text-align: center;
        }
        
        .sec-3 ul li:hover:nth-child(1) {
            background-color: #3b5999;
        }
        
        .sec-3 ul li:hover:nth-child(2) {
            background-color: #55acee;
        }
        
        .sec-3 ul li:hover:nth-child(3) {
            background-color: #dd4b39;
        }
        
        .sec-3 ul li:hover:nth-child(4) {
            background-color: #0077B5;
        }
        
        .sec-3 ul li:hover:nth-child(5) {
            background-color: #e4405f;
        }
        
        .sec-4 {
            display: flex;
            justify-content: center;
            background-color: black;
            padding: 30px;
            color: gray;
        }
        
        .sec-4 p {
            position: relative;
        }
        
        .sec-4 p::after {
            content: '';
            display: block;
            width: 0;
            height: 2px;
            position: absolute;
            right: 0;
            bottom: -10px;
            background-color: yellow;
            transition: all .4s;
            -webkit-transition: all .4s;
            -moz-transition: all .4s;
            -ms-transition: all .4s;
            -o-transition: all .4s;
        }
        
        .sec-4 p:hover::after {
            width: 100%;
        }
        
        hr {
            opacity: 0.2;
        }
        
        @media(max-width:840px) {
            .main-content {
                width: 100%;
                height: 100px;
                display: flex;
                justify-content: center;
                align-items: center;
                font-size: 40px;
                color: gray;
            }
            footer {
                width: 100%;
                background-color: #26272b;
            }
            .sec-1 {
                display: flex;
                flex-wrap: wrap;
                flex-direction: row;
                justify-content: space-between;
                padding: 30px 15px;
            }
            .about {
                width: 100%;
                margin-bottom: 20px;
            }
            .sec-1 h2 {
                font-size: 18px;
                color: lightgray;
                text-transform: uppercase;
                margin-bottom: 10px;
            }
            .about p {
                text-align: justify;
                color: lightgray;
                line-height: 24px;
                margin-top: 10px;
            }
            .sec-1 ul {
                list-style-type: none;
                line-height: 24px;
            }
            .sec-1 ul li {
                list-style-type: none;
                line-height: 24px;
            }
            a {
                text-decoration: none;
                color: gray;
            }
            a:hover {
                color: orange;
            }
            span {
                color: gray;
            }
            i {
                color: gray;
                font-size: 20px;
            }
            .sec-2 {
                display: flex;
                justify-content: center;
                padding: 30px;
            }
            .sec-2 h2 {
                color: lightgray;
                font-size: 24px;
                padding: 0;
            }
            .sec-2 a {
                display: inline-block;
                padding: 10px 15px;
                color: white;
                font-size: 18px;
                background-color: red;
                margin-left: 10px;
                border-radius: 15px;
                -webkit-border-radius: 15px;
                -moz-border-radius: 15px;
                -ms-border-radius: 15px;
                -o-border-radius: 15px;
            }
            .sec-2 a:hover {
                background-color: orange;
            }
            .sec-3 {
                display: flex;
                justify-content: center;
                padding: 20px;
            }
            .sec-3 ul {
                list-style-type: none;
                margin: 20px;
            }
            .sec-3 ul li {
                display: inline-block;
                width: 60px;
                height: 60px;
                padding: 20px;
                background-color: #424242;
                border-radius: 50%;
                -webkit-border-radius: 50%;
                -moz-border-radius: 50%;
                -ms-border-radius: 50%;
                -o-border-radius: 50%;
                margin-right: 20px;
            }
            .sec-3 ul li i {
                color: white;
                font-size: 24px;
                line-height: 20px;
                text-align: center;
            }
            .sec-3 ul li:hover:nth-child(1) {
                background-color: #3b5999;
            }
            .sec-3 ul li:hover:nth-child(2) {
                background-color: #55acee;
            }
            .sec-3 ul li:hover:nth-child(3) {
                background-color: #dd4b39;
            }
            .sec-3 ul li:hover:nth-child(4) {
                background-color: #0077B5;
            }
            .sec-3 ul li:hover:nth-child(5) {
                background-color: #e4405f;
            }
            .sec-4 {
                display: flex;
                justify-content: center;
                background-color: black;
                padding: 30px;
                color: gray;
            }
            .sec-4 p {
                position: relative;
            }
            .sec-4 p::after {
                content: '';
                display: block;
                width: 0;
                height: 2px;
                position: absolute;
                right: 0;
                bottom: -10px;
                background-color: yellow;
                transition: all .4s;
                -webkit-transition: all .4s;
                -moz-transition: all .4s;
                -ms-transition: all .4s;
                -o-transition: all .4s;
            }
            .sec-4 p:hover::after {
                width: 100%;
            }
            hr {
                opacity: 0.2;
            }
        }
        
        @media(max-width:509px) {
            .main-content {
                width: 100%;
                height: 100px;
                display: flex;
                justify-content: center;
                align-items: center;
                font-size: 40px;
                color: gray;
            }
            footer {
                width: 100%;
                background-color: #26272b;
            }
            .sec-1 {
                display: flex;
                flex-direction: column;
                justify-content: space-between;
                padding: 30px 15px;
            }
            .about {
                width: 100%;
            }
            .sec-1 h2 {
                font-size: 18px;
                color: lightgray;
                text-transform: uppercase;
                margin-top: 20px;
            }
            .about p {
                text-align: justify;
                color: lightgray;
                line-height: 24px;
                margin-top: 10px;
            }
            .sec-1 ul {
                list-style-type: none;
                line-height: 24px;
            }
            .sec-1 ul li {
                list-style-type: none;
                line-height: 24px;
            }
            a {
                text-decoration: none;
                color: gray;
            }
            a:hover {
                color: orange;
            }
            span {
                color: gray;
            }
            i {
                color: gray;
                font-size: 20px;
            }
            .sec-2 {
                display: flex;
                justify-content: center;
                padding: 30px;
            }
            .sec-2 h2 {
                color: lightgray;
                font-size: 24px;
                padding: 0;
            }
            .sec-2 a {
                display: inline-block;
                padding: 10px 15px;
                color: white;
                font-size: 18px;
                background-color: red;
                margin-left: 10px;
                border-radius: 15px;
                -webkit-border-radius: 15px;
                -moz-border-radius: 15px;
                -ms-border-radius: 15px;
                -o-border-radius: 15px;
            }
            .sec-2 a:hover {
                background-color: orange;
            }
            .sec-3 {
                display: flex;
                justify-content: center;
                padding: 20px;
            }
            .sec-3 ul {
                list-style-type: none;
                margin: 20px;
            }
            .sec-3 ul li {
                display: inline-block;
                width: 40px;
                height: 40px;
                padding: 10px;
                background-color: #424242;
                border-radius: 50%;
                -webkit-border-radius: 50%;
                -moz-border-radius: 50%;
                -ms-border-radius: 50%;
                -o-border-radius: 50%;
                margin-right: 10px;
            }
            .sec-3 ul li i {
                color: white;
                font-size: 24px;
                line-height: 20px;
                text-align: center;
            }
            .sec-3 ul li:hover:nth-child(1) {
                background-color: #3b5999;
            }
            .sec-3 ul li:hover:nth-child(2) {
                background-color: #55acee;
            }
            .sec-3 ul li:hover:nth-child(3) {
                background-color: #dd4b39;
            }
            .sec-3 ul li:hover:nth-child(4) {
                background-color: #0077B5;
            }
            .sec-3 ul li:hover:nth-child(5) {
                background-color: #e4405f;
            }
            .sec-4 {
                display: flex;
                justify-content: center;
                background-color: black;
                padding: 30px;
                color: gray;
            }
            .sec-4 p {
                position: relative;
            }
            .sec-4 p::after {
                content: '';
                display: block;
                width: 0;
                height: 2px;
                position: absolute;
                right: 0;
                bottom: -10px;
                background-color: yellow;
                transition: all .4s;
                -webkit-transition: all .4s;
                -moz-transition: all .4s;
                -ms-transition: all .4s;
                -o-transition: all .4s;
            }
            .sec-4 p:hover::after {
                width: 100%;
            }
            hr {
                opacity: 0.2;
            }
        }