/* 基础样式重置和字体设置 */
body, button, input, select, textarea, h1, h2, h3, h4, h5, h6, a, p {
    font-family: "Arial";
}
/* 根元素设置，基于1920px设计稿 */
:root {
    font-size: 18px; /* 基础字体大小 */
    --base-font-size: 1rem; /* 基础字体大小 */
    --container-padding: 3.778rem; /* 容器内边距 */
    --container-max-width: 71.111rem; /* 最大宽度 */
    --subsection-padding: 6.222rem; /* 区块内边距 */
    --container-gap:1.5rem; /* 容器间隔 */
    --subsection-max-width: 64rem; /* 二级页面最大宽度 */
    --subsection-padding-large: 3.111rem;
    --h1-font-size:2.5rem;
    --h2-font-size:2.3rem;
    --h3-font-size:1.8rem;
    --h4-font-size:1.4rem;
    --h5-font-size:1.2rem;
    --h6-font-size:1rem;
    --text-large: 1rem;
    --text-medium: 1.111rem;
    --text-regular: 0.889rem;
    --text-small: 0.778rem;
    --text-tiny: 0.667rem;
    --padding-global:1.778rem;
    --padding-section-Xlarge:6.222rem;
    --padding-section-large:3.111rem;
    --padding-section-medium:2.222rem;
    --padding-section-small:1.333rem;
}
.nav_menu li a{font-size: 1rem;}
.sub_menu li a{font-size: 0.9rem;}
.nav_menu li:nth-child(2) .sub_menu ul li{padding: 0.1rem 0;}
.banner h1,.about-banner h1{font-size: 2.5rem;}
.subsection .big_title h2{font-size: 2rem;}
.milestones ul{align-items: start;}
.milestones p{line-height: 120%; text-align: center;}
.list-unstyled li svg{flex: 0 0 24px;}
.nav_menu .sub_menu{width: 35rem;}
.nav_menu li:nth-child(2) .sub_menu ul{width: 35rem;}
.nav_menu li:nth-child(3) .sub_menu ul{width: 40rem;}
.nav_menu li:nth-child(3) .sub_menu .sub_menu_list{left: 50%;}
.Home_USP_item .Home_USP_item_text p{font-size: 1rem;}
.joinus_left ul li:first-child .box_text{padding-top: 1.5rem;}
.joinus_box .box_text{justify-content: start;}
.joinus_box .box_text h3{font-size: 2rem;}
.form_btn{color: #425C56;}

@media screen and (max-width: 1450px) {
    .nav_menu li a{font-size: 0.8rem;}
    .sub_menu li a{font-size: 0.8rem;}
    .nav_menu ul{gap: 1rem;}
}

@media screen and (max-width: 1250px) {
    .nav_menu li a{font-size: 0.7rem;}
    .sub_menu li a{font-size: 0.7rem;}
    .nav_menu ul{gap: 1rem;}
    .nav_btn a{padding:0.3rem 0.5rem;}
    .languages a{margin: 0 1rem; padding:0.45rem 0.6rem;}
}

@media screen and (max-width: 1150px) {
    .nav_menu li a{font-size: 0.65rem;}
    .sub_menu li a{font-size: 0.65rem;}
    .nav_menu ul{gap: 0.5em;}
    .nav_btn a{padding:0.3rem 0.5rem;}
    .languages a{margin: 0 1rem; padding:0.45rem 0.6rem;}
}

@media screen and (max-width: 480px) {
    :root{
        font-size: 12px;
        --base-font-size: 1rem; /* 基础字体大小 */
        --container-padding: 1.667rem; /* 容器内边距 */
        --container-max-width: 40rem; /* 最大宽度 */
        --subsection-padding: 5.333rem; /* 区块内边距 */
        --container-gap:1.778rem; /* 容器间隔 */
        --h1-font-size:2.5rem;
        --h2-font-size:2.3rem;
        --h3-font-size:1.8rem;
        --h4-font-size:1.4rem;
        --h5-font-size:1.2rem;
        --h6-font-size:1rem;
        --text-large: 1rem;
        --text-medium: 1.111rem;
        --text-regular: 0.889rem;
        --text-small: 0.778rem;
        --text-tiny: 0.667rem;
        --padding-global:1.667rem;
        --padding-section-Xlarge:5.333rem;
        --padding-section-large:2.667rem;
        --padding-section-medium:2rem;
        --padding-section-small:1.333rem;
    }
    .banner h1,.about-banner h1,.banner .banner_text h1{font-size: 2.5rem;}
    .subsection .big_title h2, .subsection_white .big_title h2{font-size: 2rem;}
    .form_group label{height: auto;}
    .qa_item h4{font-size: 1.5rem;}
    .service_types dd p{width: 100%;}
    .service_types dd svg{flex:0 0 1.778rem;}
    .fees ul li{margin-bottom: 2rem;}
}