body {
    text-align: center;
    font-family: sans-serif;
}

h1 {
    max-width: 44rem;
    margin: 0 auto;
    vertical-align: middle;
    font-size: 2.5rem;
    letter-spacing: 3px;
    font-family: serif;
    cursor: pointer;
    background: #5d5d5d;
    color: white;
    padding: 1.5rem 0;
}

h1 em {
    font-size: 4rem;
}

h1 img {
    vertical-align: text-bottom;
    max-width: 64px;
}

/*Nav*/
nav {
    max-width: 44rem;
    margin: 0.5rem auto;
    padding: 0.5rem 0;
    text-align: left;
    border-bottom: 1px solid lightgray;
}

nav a {
    text-decoration: none;
    color: black;
    margin-right: 0.5rem;
    padding-bottom: 0.4rem;
}

nav a:hover {
    color: blue;
}

nav a:not(:first-child) {
    margin-left: 0.5rem;
}

nav .nav-active {
    color: blue;
    border-bottom: 3px solid blue;
}

/*banner images*/
.banner-images {
    max-width: 44rem;
    display: block;
    margin: 1rem auto 0 auto;
}

.banner-images .service-list {
    width: 49%;
    display: inline-block;
    vertical-align: top;
}

.banner-images .service-list:first-child {
    border-right: 1px solid lightgray;
}

.banner-images .service-list .service-list-img {
    max-height: 180px;
    overflow: hidden;
}

.banner-images img {
    width: 80%;
}

.service-list .service-list-content {
    margin-bottom: 1rem;
}

.service-list .service-list-content ul {
    text-align: left;
    max-width: 12rem;
    margin: auto;
}

.service-list .service-list-content .hidden-li {
    list-style: none;
    height: 1rem;
}


/*Home page*/
.introduction {
    max-width: 44rem;
    margin: auto;
    text-align: left;
}

.introduction div {
    margin-bottom: 1rem;
}

.our-services {
    max-width: 44rem;
    margin: auto;
    text-align: left;
}

.our-services ul {
    max-width: 20rem;
    margin: auto;
}

.pricing {
    max-width: 44rem;
    margin: auto;
    text-align: left;
}

.service-area {
    max-width: 44rem;
    margin: auto;
    text-align: left;
}

.service-area ul {
    max-width: 20rem;
    margin: 1rem auto;
}

.brands {
    max-width: 44rem;
    margin: auto;
    text-align: left;
}

/*advantages section*/
.advantages {
    max-width: 44rem;
    margin: 1rem auto;
}

.advantages a {
    display: block;
    background: #727272;
    color: white;
    text-decoration: none;
    font-size: 2rem;
    padding: 1.3rem 0;
    width: 100%;
}


/*footer style*/
.footer {
    margin: 1rem 0;
}

.footer p {
    margin: 0;
}

.footer .phone-number a {
    margin-right: 0.5rem;
}

/*******************/
/*  Service Page   */
/*******************/
.subpage-title {
    max-width: 44rem;
    margin: 1rem auto;
    text-align: center;
}

.subpage-description {
    max-width: 44rem;
    margin: 1rem auto;
    text-align: left;
}

.common-section {
    max-width: 44rem;
    margin: auto;
    text-align: left;
}

.common-section ol li {
    margin: 0.5rem 0;
}

.video-section {
    text-align: center;
}

.video-section div {
    max-width: 30rem;
    margin: auto;
    position: relative;
    padding-bottom: 38.25%; /* 16:9 */
    height: 0;
}

.video-section p {
    color: gray;
}

.video-section iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}

/*media query is necessary*/
@media screen and (max-width: 710px) {
    .banner-images .service-list .service-list-img {
        max-height: 160px;
    }
}


@media screen and (max-width: 600px) {
    h1 {
        font-size: 2rem;
    }

    h1 em {
        font-size: 3.5rem;
    }

    .banner-images .service-list .service-list-img {
        max-height: 140px;
    }
}

@media screen and (max-width: 500px) {
    h1 {
        font-size: 1.5rem;
    }

    h1 em {
        font-size: 3rem;
    }

    .banner-images .service-list {
        display: inline;
        border: none !important;
    }

    .banner-images .service-list .service-list-img {
        max-height: 180px;
    }
}

@media screen and (max-width: 440px) {
    h1 {
        font-size: 1.2rem;
    }

    h1 em {
        font-size: 2rem;
    }

    h1 img {
        max-width: 35px;
    }
}

@media screen and (max-width: 375px) {

    h1 {
        white-space: nowrap;
    }

    .banner-images .service-list {
        display: inline;
    }

    .advantages a {
        font-size: 1.5rem;
    }

    .video-section div {
        padding-bottom: 58.25%; /* 16:9 */
    }
}

@media screen and (max-width: 340px) {
    h1 {
        font-size: 1rem;
    }

    h1 em {
        font-size: 1.5rem;
    }
}