:root {
    --main-color: rgba(83,107,175,1);
    --main-color-opacity: 83,107,175;
    --accent-color: linear-gradient(to right,rgba(68,90,170,1), rgba(120,159,218,1));
    --text-color: rgba(35,24,21,1);
    --text-color-opacity: 35,24,21;
    --clear-color: rgba(255,255,255,1);
    --clear-color-opacity: 255,255,255;
}
*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
html{
    font-size: clamp(14px, 1vw, 18px);
}
@media (min-width: 1600px){
    html {
        font-size: clamp(12px, 0.8vw, 16px);
    }
}
@media (min-width: 481px) and (max-width: 768px){
    html {
        font-size: clamp(14px, 1.25vw, 18px);
    }
}
@media (max-width: 480px){
    html {
        font-size: clamp(14px, 1.5vw, 18px);
    }
}
@media (min-resolution: 2dppx) and (max-width: 480px){
    html {
        font-size: clamp(16px, 2vw, 20px);
    }
}


body{
    font-family: 'Noto Sans JP', sans-serif;
    color: var(--text-color);
    letter-spacing: .1rem;
    line-height: 1.7;
    overflow-x: hidden;
}
ul,ol,li{
    list-style-type: none;
}
img{
    max-width: 100%;
    height: auto;
    vertical-align: bottom;
}
a{
    text-decoration: none;
    display: block;
}

header{
    background: rgba(var(--clear-color-opacity),.7);
    padding: 1.75rem 0;
}
header section{
    max-width: 1100px;
    width: 90%;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}
header img{
    width: 270px;
    height: 42px;
    object-fit: cover;
}
header ul{
    display: flex;
    align-items: center;
    gap: 2rem;
    font-size: 1.1rem;
}
header a{
    color: var(--text-color);
}
.btn-contact{
    border: 1px solid var(--text-color);
    padding: .5rem 1.5rem;
}
#nav-toggle{
    display: none;
}
@media (max-width: 768px){
    header{
        height: 7rem;
        width: 100vw;
        position: fixed;
    }
    header section{
        display: block;
    }
    header nav{
        display: none;
    }
    .btn-contact{
        display: none;
    }
    #nav-toggle{
        z-index: 100;
        width: 5rem;
        height: 5rem;
        background: var(--main-color);
        border-radius: 50%;
        position: fixed;
        top: 1rem;
        right: 1rem;
        display: flex;
        flex-direction: column;
        align-items: center;
        justify-content: center;
        gap: .75rem;
    }
    #nav-toggle span{
        background: var(--clear-color);
        width: 3rem;
        height: .25rem;
        transition: 0.3s ease-in-out;
    }
    .open #nav-toggle{
        gap: 0;
    }
    .open #nav-toggle span:nth-child(1) {
        transform: rotate(-45deg) translateY(.125rem);
    }
    .open #nav-toggle span:nth-child(2) {
        display: none;
    }
    .open #nav-toggle span:nth-child(3) {
        transform: rotate(45deg) translateY(-.125rem);
    }

    .open nav{
        display: block;
        position: fixed;
        top: 7rem;
        left: 0;
        width: 100vw;
        height: auto;
        background: var(--accent-color);
        z-index: 20;
        transition: 0.3s ease-in-out;
    }
    .open ul{
        display: block;
        text-align: center;
        margin: 1.5rem auto;
    }
    .open li{
        margin-bottom: 1rem;
        font-size: 1.1rem;
        padding: 1rem;
    }
    .open .btn-contact{
        margin-bottom: 0;
        border: none;
        padding: 0;
    }
}

.contact-us{
    padding: 5rem 0;
    border-top: 1px solid var(--main-color);
}
.contact-us h3{
    text-align: center;
    font-size: 1.75rem;
    letter-spacing: .25rem;
    font-weight: normal;
    display: flex;
    flex-direction: column;
}
.contact-us h3 span{
    order: 3;
}
.contact-us h3::before{
    content: "Contact Us";
    font-size: .9rem;
    color: var(--main-color);
    order: 1;
}
.contact-us h3::after{
    content: "";
    width: 9rem;
    height: 1px;
    background: var(--text-color);
    margin: .5rem auto 1rem;
    order: 2;
}
.contact-us ul{
    max-width: 780px;
    width: 90%;
    margin: 4rem auto 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: relative;
}
.contact-us ul::after{
    content: "";
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%,-50%);
    width: 1px;
    height: 70px;
    background: var(--text-color);
}
.btn-tel{
    width: 340px;
}
.btn-tel a{
    font-size: 2.75rem;
    font-weight: bold;
    color: var(--main-color);
    display: flex;
    align-items: baseline;
    justify-content: flex-end;
    gap: .5rem;
    line-height: 1;
}
.btn-tel a::before{
    content: "";
    background: url(../images/tel.svg) no-repeat;
    width: 24px;
    height: 24px;
    background-size: cover;
}
.btn-tel span{
    text-align: right;
    margin-top: .5rem;
    display: block;
}
.btn-mail{
    background: var(--accent-color);
    width: 340px;
    line-height: 70px;
}
.btn-mail a{
    color: var(--clear-color);
    text-align: center;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: .5rem;
}
.btn-mail a::before{
    content: "";
    background: url(../images/mail.svg) no-repeat;
    width: 23px;
    height: 17px;
    background-size: cover;
}
@media (max-width: 768px){
    .contact-us{
        padding: 3rem 0;
    }
    .contact-us h3{
        font-size: 1.25rem;
        letter-spacing: .1rem;
    }
    .contact-us ul{
        display: block;
        margin: 2rem auto 0;
    }
    .contact-us ul::after{
        display: none;
    }
    .btn-tel{
        margin: 0 auto 2rem;
    }
    .btn-tel a{
        justify-content: center;
    }
    .btn-mail{
        margin: 0 auto;
    }
}


#back-to-top {
    position: fixed;
    bottom: 20px;
    right: 20px;
    width: 50px;
    height: 50px;
    border: none;
    border-radius: 50%;
    background-color: var(--main-color);
    color: var(--clear-color);
    font-size: 18px;
    cursor: pointer;
    display: none;
    z-index: 1000;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.2);
    transition: opacity 0.3s ease;
}

footer{
    background: var(--main-color);
    padding: 5rem 0 2.5rem;
}
footer section{
    max-width: 1100px;
    width: 90%;
    margin: 0 auto;
    display: grid;
    justify-content: space-between;
    gap: 1rem;
}
footer h3{
    grid-column: 1;
    grid-row: 1;
}
footer img{
    width: 270px;
    height: 42px;
    object-fit: cover;
}
footer address{
    grid-column: 1;
    grid-row: 2;
    color: var(--clear-color);
    font-style: normal;
}
footer nav{
    grid-column: 2;
    grid-row: 1;
}
footer ul{
    display: flex;
    justify-content: flex-end;
    gap: 2rem;
}
footer a{
    color: var(--clear-color);   
}
footer p{
    grid-column: 2;
    grid-row: 2;
    text-align: right;
    padding-top: 4rem;
}
footer small{
    font-size: .9rem;
    color: var(--clear-color);   
}
@media (max-width: 768px){
    footer{
        padding: 3rem 0 1.5rem;
    }
    footer section{
        display: block;
    }
    footer h3{
        text-align: center;
    }
    footer address{
        text-align: center;
        margin: 1rem auto;
    }
    footer ul{
        justify-content: center;
        gap: 1rem;
    }
    footer p{
        padding-top: 2rem;
        text-align: center;
    }
}