/* 全局样式和重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #fff;
    overflow-x: hidden;
}

a {
    text-decoration: none;
}

/* 容器 */
.container {
    max-width: 1200px;
    margin: 0 auto;
}

.f40 {
    font-size: 40px;
}

.f35 {
    font-size: 35px;
}

.f30 {
    font-size: 30px;
}

.f28 {
    font-size: 28px;
}

.f18 {
    font-size: 18px;
}

.f24 {
    font-size: 24px;
}

.f22 {
    font-size: 22px;
}

.f20 {
    font-size: 20px;
}

.f18 {
    font-size: 18px;
}

.f16 {
    font-size: 16px;
}

.f14 {
    font-size: 14px;
}

.f12 {
    font-size: 12px;
}

/* 导航栏 */
.navbar {
    background-color: #fff;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    transition: all 0.3s ease;
}

.navbar.scrolled {
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 80px;
}

.navbar-brand .logo-link {
    display: block;
}

.logo-image {
    height: 55px;
    width: auto;
    display: block;
    transition: height 0.3s ease;
    object-fit: contain;
}

/* 汉堡菜单按钮 */
.navbar-toggle {
    display: none;
    flex-direction: column;
    justify-content: space-between;
    width: 30px;
    height: 21px;
    cursor: pointer;
    z-index: 1001;
    transition: all 0.3s ease;
}

.navbar-toggle .bar {
    width: 100%;
    height: 3px;
    background-color: #333;
    border-radius: 3px;
    transition: all 0.3s ease;
}

/* 汉堡菜单激活状态 */
.navbar-toggle.active .bar:nth-child(1) {
    transform: rotate(-45deg) translate(-5px, 6px);
}

.navbar-toggle.active .bar:nth-child(2) {
    opacity: 0;
}

.navbar-toggle.active .bar:nth-child(3) {
    transform: rotate(45deg) translate(-5px, -6px);
}

/* 汉堡菜单悬停效果 */
.navbar-toggle:hover .bar {
    background-color: #C7000B;
}

.navbar-nav ul {
    display: flex;
    list-style: none;
    gap: 30px;
    transition: all 0.3s ease;
}

.navbar-nav a {
    text-decoration: none;
    color: #333;
    font-weight: 100;
    transition: color 0.3s ease;
    position: relative;
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    padding: 8px 0;
}

.navbar-nav a .nav-ru {
    font-weight: 500;
    color: #333;
    transition: font-size 0.3s ease;
}

.navbar-nav a .nav-cn {
    color: #99A1AF;
    margin-top: 2px;
    transition: font-size 0.3s ease;
}

.navbar-nav a:hover .nav-ru {
    color: #C7000B;
}

.navbar-nav a:hover .nav-cn {
    color: #C7000B;
}

.navbar-nav a:hover {
    color: #C7000B;
}

.navbar-nav a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: #C7000B;
    transition: width 0.3s ease;
}

.navbar-nav a:hover::after {
    width: 100%;
}

/* 导航栏激活状态 */
.navbar-nav a.active {
    color: #C7000B;
}

.navbar-nav a.active .nav-ru {
    color: #C7000B;
}

.navbar-nav a.active .nav-cn {
    color: #C7000B;
}

.navbar-nav a.active::after {
    width: 100%;
}

/* 通用部分样式 */
section {
    padding: 80px 0;
}

.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-header h2 {
    font-size: 48px;
    font-weight: 300;
    color: #101828;
    margin-bottom: 12px;
}

.section-header .subtitle {
    font-size: 18px;
    color: #99A1AF;
}

/* 按钮样式 */
.btn {
    display: inline-flex;
    flex-direction: column;
    align-items: flex-start;
    padding: 16px 32px;
    text-decoration: none;
    border-radius: 4px;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
    border: none;
    cursor: pointer;
    font-size: 16px;
    font-weight: 500;
    font-family: 'Microsoft YaHei', Arial, sans-serif;
}

.btn-primary {
    background-color: #C7000B;
    color: white;
}

.btn-primary:hover {
    background-color: #a80009;
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(199, 0, 11, 0.3);
}

.btn-outline {
    border: 2px solid #D1D5DC;
    color: #364153;
}

.btn-outline:hover {
    border-color: #C7000B;
    color: #C7000B;
    transform: translateY(-2px);
}

.btn .btn-subtitle {
    font-size: 12px;
    opacity: 0.9;
    margin-top: 4px;
}

.center-btn {
    text-align: center;
    margin-top: 60px;
}

/* 页脚 */
.footer {
    background-color: white;
    border-top: 1px solid #F3F4F6;
    padding: 60px 0 30px;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 40px;
    margin-bottom: 40px;
}

.footer-brand {
    flex: 1;
    min-width: 250px;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 24px;
}

.logo-icon {
    height: 60px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.logo-text h3 {
    font-size: 16px;
    font-weight: 700;
    color: #101828;
    margin-bottom: 4px;
}

.logo-text p {
    font-size: 12px;
    color: #6A7282;
    margin: 0;
}

.footer-description {
    margin-bottom: 16px;
}

.footer-description .ru-text {
    display: block;
    font-size: 14px;
    color: #4A5565;
    line-height: 20px;
}

.footer-description .cn-text {
    display: block;
    font-size: 12px;
    color: #6A7282;
    line-height: 16px;
    margin-bottom: 8px;
}

.footer-certification .ru-text {
    display: block;
    font-size: 14px;
    color: #4A5565;
    line-height: 20px;
}

.footer-certification .cn-text {
    display: block;
    font-size: 12px;
    color: #6A7282;
    line-height: 16px;
    margin-bottom: 8px;
}

.footer-links,
.footer-certifications {
    flex: 1;
    min-width: 200px;
}

.footer-title {
    margin-bottom: 24px;
}

.footer-title .ru-text {
    display: block;
    font-size: 18px;
    font-weight: 600;
    color: #101828;
    line-height: 27px;
    margin-bottom: 4px;
}

.footer-title .cn-text {
    display: block;
    font-size: 12px;
    font-weight: 600;
    color: #6A7282;
    line-height: 16px;
}

.footer-links ul {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.footer-links a {
    text-decoration: none;
    display: block;
}

.footer-links .ru-text {
    display: block;
    font-size: 14px;
    color: #1A1A1A;
    line-height: 20px;
    margin-bottom: 4px;
}

.footer-links .cn-text {
    display: block;
    font-size: 12px;
    color: #6A7282;
    line-height: 16px;
}

.footer-certifications ul {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.footer-certifications li {
    display: flex;
    flex-direction: column;
}

.footer-certifications .ru-text {
    display: block;
    font-size: 14px;
    color: #1A1A1A;
    line-height: 20px;
    margin-bottom: 4px;
}

.footer-certifications .cn-text {
    display: block;
    font-size: 12px;
    color: #6A7282;
    line-height: 16px;
}

.footer-bottom {
    border-top: 1px solid #1E2939;
    padding-top: 30px;
}

.footer-copyright {
    text-align: center;
    margin: 0;
}

.footer-copyright .ru-text {
    display: block;
    font-size: 14px;
    color: #1A1A1A;
    line-height: 20px;
    margin-bottom: 8px;
}

.footer-copyright .cn-text {
    display: block;
    font-size: 12px;
    color: #6A7282;
    line-height: 16px;
}

/* 响应式设计 */
@media (max-width: 1200px) {
    .container {
        max-width: 960px;
    }

    .navbar-nav ul {
        gap: 25px;
    }
}

@media (max-width: 992px) {
    .container {
        max-width: 720px;
    }

    .navbar-nav ul {
        gap: 20px;
    }

    .navbar-nav a .nav-ru {
        font-size: 13px;
    }

    .navbar-nav a .nav-cn {
        font-size: 11px;
    }

    .footer-content {
        gap: 30px;
    }
}

@media (max-width: 768px) {
    .container {
        max-width: 540px;
    }

    /* 汉堡菜单显示 */
    .navbar-toggle {
        display: flex;
    }

    .navbar .container {
        flex-direction: row;
        gap: 0;
        padding: 15px 20px;
    }

    .navbar-nav {
        position: fixed;
        top: 0;
        right: -100%;
        width: 280px;
        height: 100vh;
        background-color: white;
        box-shadow: -2px 0 10px rgba(0, 0, 0, 0.1);
        transition: right 0.3s ease;
        z-index: 1000;
        padding-top: 80px;
    }

    .navbar-nav.active {
        right: 0;
    }

    .navbar-nav ul {
        flex-direction: column;
        gap: 0;
        align-items: center;
    }

    .navbar-nav li {
        width: 100%;
        text-align: center;
    }

    .navbar-nav a {
        padding: 15px 0;
        border-bottom: 1px solid #f0f0f0;
    }

    .navbar-nav a .nav-ru {
        font-size: 14px;
    }

    .navbar-nav a .nav-cn {
        font-size: 12px;
    }

    .navbar-brand .logo-image {
        height: 50px;
    }

    section {
        padding: 80px 0;
    }

    .section-header h2 {
        font-size: 36px;
    }

    .footer-content {
        flex-direction: column;
        gap: 40px;
    }

    .footer-brand,
    .footer-links,
    .footer-certifications {
        min-width: 100%;
        text-align: center;
    }

    .footer-links h3 {
        margin-bottom: 15px;
    }

    .footer-links ul {
        display: flex;
        flex-wrap: wrap;
        justify-content: center;
        gap: 15px;
    }

    .footer-links li {
        margin-bottom: 0;
    }

    .footer-certifications ul {
        justify-content: center;
    }
}

@media (max-width: 576px) {
    .container {
        max-width: 100%;
        padding: 0 15px;
    }

    .navbar .container {
        padding: 10px 15px;
    }

    .navbar-brand .logo-image {
        height: 40px;
    }

    .navbar-nav {
        width: 100%;
    }

    section {
        padding: 60px 0;
    }

    .section-header h2 {
        font-size: 28px;
    }

    .btn {
        padding: 12px 24px;
    }

    .footer {
        padding: 40px 0 20px;
    }

    .footer-content {
        gap: 30px;
    }

    .footer-brand .logo {
        height: 40px;
        margin-bottom: 15px;
    }

    .footer-brand .description {
        font-size: 13px;
        line-height: 18px;
    }

    .footer-bottom {
        padding-top: 20px;
    }

    .footer-copyright .ru-text {
        font-size: 11px;
        line-height: 16px;
    }

    .footer-copyright .cn-text {
        font-size: 11px;
        line-height: 14px;
    }
}

/* 动画效果 */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in-up {
    animation: fadeInUp 0.6s ease-out;
}

/* 滚动条样式 */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: #f1f1f1;
}

::-webkit-scrollbar-thumb {
    background: #C7000B;
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: #a80009;
}

/* 加载动画 */
.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 2px solid #f3f3f3;
    border-top: 2px solid #C7000B;
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% {
        transform: rotate(0deg);
    }

    100% {
        transform: rotate(360deg);
    }
}

/* 涟漪效果 */
.ripple {
    position: absolute;
    border-radius: 50%;
    background-color: rgba(255, 255, 255, 0.5);
    transform: scale(0);
    animation: ripple 0.6s linear;
    pointer-events: none;
}

@keyframes ripple {
    to {
        transform: scale(4);
        opacity: 0;
    }
}

/* 平滑滚动 */
html {
    scroll-behavior: smooth;
}

/* 选择文本样式 */
::selection {
    background-color: #C7000B;
    color: white;
}

/* 焦点样式 */
*:focus {
    outline: 2px solid #C7000B;
    outline-offset: 2px;
}

/* 图片加载效果 */
img {
    transition: opacity 0.3s ease;
}

img.loading {
    opacity: 0.5;
}

/* 导航栏链接激活状态 */
.navbar-nav a.active {
    color: #C7000B;
}

.navbar-nav a.active::after {
    width: 100%;
}