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

:root {
    --primary-color: #2563eb;
    --secondary-color: #1e40af;
    --text-color: #1f2937;
    --light-text: #6b7280;
    --background: #ffffff;
    --light-background: #f3f4f6;
    --max-width: 1200px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    padding-top: 80px; /* 为固定导航栏留出空间 */
}

/* 导航栏样式 */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: var(--background);
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    z-index: 1000;
    height: 80px;
    display: flex;
    align-items: center;
}

.nav-container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
}

.logo {
    font-size: 1.75rem;
    font-weight: bold;
    color: var(--primary-color);
    text-decoration: none;
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: 2rem;
}

.nav-link {
    font-size: 1.1rem;
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    white-space: nowrap;
    min-width: max-content;
}

.nav-link i {
    font-size: 0.8rem;
    transition: transform 0.3s;
    margin-left: 0.25rem;
}

.nav-link:hover {
    color: var(--primary-color);
}

.nav-link:hover i {
    transform: rotate(180deg);
}

/* 按钮样式 */
.primary-btn, .cta-button {
    background: var(--primary-color);
    color: white !important;
    padding: 0.75rem 1.5rem;
    border-radius: 0.375rem;
    transition: background-color 0.3s;
    font-size: 1.1rem;
    font-weight: 500;
    text-decoration: none;
    display: inline-block;
    border: none;
    cursor: pointer;
}

.primary-btn:hover, .cta-button:hover {
    background: var(--secondary-color);
}

.secondary-btn {
    background: transparent;
    color: var(--text-color) !important;
    padding: 0.75rem 1.5rem;
    border-radius: 0.375rem;
    border: 2px solid var(--primary-color);
    transition: all 0.3s;
    font-size: 1.1rem;
    font-weight: 500;
    text-decoration: none;
    display: inline-block;
    cursor: pointer;
}

.secondary-btn:hover {
    background: var(--primary-color);
    color: white !important;
}

/* 下拉菜单样式 */
.dropdown {
    position: relative;
    display: flex;
    align-items: center;
}

.dropdown-content {
    position: absolute;
    top: 100%;
    left: 0;
    background: white;
    min-width: 280px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    border-radius: 0.5rem;
    padding: 1rem 0;
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    transition: all 0.3s;
}

.dropdown:hover .dropdown-content {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.dropdown-content a {
    display: block;
    padding: 0.75rem 1.5rem;
    color: var(--text-color);
    text-decoration: none;
    font-size: 1rem;
    transition: background-color 0.3s;
    white-space: nowrap;
}

.dropdown-content a:hover {
    background-color: var(--light-background);
    color: var(--primary-color);
}

.nav-buttons {
    display: flex;
    align-items: center;
    gap: 1.5rem;
    margin-left: 1rem;
}

.signin-link {
    font-weight: 600;
    white-space: nowrap;
}

/* 语言选择器样式 */
.language-selector {
    margin-left: 20px;
}

.language-selector .current-lang {
    display: flex;
    align-items: center;
    padding: 8px 15px;
    font-weight: 500;
    border: none;
    background: transparent;
    cursor: pointer;
    font-size: 1rem;
    color: var(--text-color);
    outline: none;
    -webkit-appearance: none;
    -moz-appearance: none;
    appearance: none;
    background-image: url("data:image/svg+xml;charset=UTF-8,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='currentColor' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3e%3cpolyline points='6 9 12 15 18 9'%3e%3c/polyline%3e%3c/svg%3e");
    background-repeat: no-repeat;
    background-position: right 0.5rem center;
    background-size: 1em;
    padding-right: 2rem;
}

.language-selector .current-lang:hover {
    color: var(--primary-color);
}

/* 移动端菜单按钮 */
.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 6px;
    cursor: pointer;
    padding: 0.5rem;
}

.mobile-menu-btn span {
    width: 30px;
    height: 2px;
    background: var(--text-color);
    transition: all 0.3s;
}

.mobile-menu-btn.active span:nth-child(1) {
    transform: rotate(45deg) translate(8px, 8px);
}

.mobile-menu-btn.active span:nth-child(2) {
    opacity: 0;
}

.mobile-menu-btn.active span:nth-child(3) {
    transform: rotate(-45deg) translate(7px, -7px);
}

/* 移动端适配 */
@media (max-width: 1024px) {
    .nav-menu {
        gap: 1.5rem;
    }

    .nav-link {
        font-size: 1rem;
    }

    .primary-btn, .secondary-btn, .cta-button {
        padding: 0.6rem 1.2rem;
        font-size: 1rem;
    }
}

@media (max-width: 768px) {
    .header {
        height: 70px;
    }

    .nav-container {
        padding: 0 1.25rem;
    }

    /* 隐藏顶部的按钮和语言选择器 */
    .nav-container > .nav-buttons,
    .nav-container > .language-selector {
        display: none;
    }

    .mobile-menu-btn {
        display: flex;
        border: none;
        background: transparent;
        margin-left: 1rem;
    }

    .nav-menu {
        display: none;
        position: fixed;
        top: 70px;
        right: -100%;
        width: 100%;
        height: calc(100vh - 70px);
        background: white;
        padding: 1.5rem;
        flex-direction: column;
        align-items: stretch;
        gap: 0;
        overflow-y: auto;
        transition: right 0.3s ease-in-out;
    }

    .nav-menu.active {
        display: flex;
        right: 0;
    }

    .nav-link {
        padding: 1rem 0;
        font-size: 1.125rem;
        border-bottom: 1px solid var(--light-background);
    }

    .dropdown {
        flex-direction: column;
        align-items: stretch;
    }

    .dropdown-content {
        position: static;
        opacity: 1;
        visibility: visible;
        transform: none;
        box-shadow: none;
        padding: 0;
        max-height: 0;
        overflow: hidden;
        transition: max-height 0.3s ease-in-out;
    }

    .dropdown.active .dropdown-content {
        max-height: 500px;
        padding: 0.5rem 0;
    }

    .dropdown-content a {
        padding: 0.75rem 1rem;
        margin-left: 1rem;
        border-left: 2px solid var(--light-background);
    }

    /* 在移动菜单中显示按钮和语言选择器 */
    .nav-menu .nav-buttons {
        display: flex;
        margin: 1.5rem 0 0;
        flex-direction: column;
        gap: 1rem;
        align-items: stretch;
        order: 999;
    }

    .nav-menu .language-selector {
        display: block;
        /* margin: 1.5rem 0; */
        text-align: center;
        order: 998;
    }

    .signin-link {
        text-align: center;
        padding: 0.75rem;
    }

    .cta-button {
        width: 100%;
        text-align: center;
    }

    .language-selector {
        margin: 1.5rem 0;
        text-align: center;
    }

    .language-selector .current-lang {
        width: 100%;
        padding: 0.75rem;
        text-align: center;
        background-position: right 1rem center;
    }

    /* 移动端菜单按钮动画 */
    .mobile-menu-btn span {
        width: 24px;
        height: 2px;
        background: var(--text-color);
        transition: all 0.3s;
    }

    .mobile-menu-btn.active span:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }

    .mobile-menu-btn.active span:nth-child(2) {
        opacity: 0;
    }

    .mobile-menu-btn.active span:nth-child(3) {
        transform: rotate(-45deg) translate(5px, -5px);
    }

    /* 页脚移动端适配 */
    .footer-nav {
        grid-template-columns: 1fr;
        gap: 2rem;
        text-align: center;
    }

    .footer-nav .nav-group {
        display: none !important; /* 强制隐藏所有导航组 */
    }

    .footer-bottom {
        margin-top: 0;
        padding-top: 2rem;
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }

    .footer-links {
        flex-direction: column;
        gap: 0.5rem;
    }
}

/* 移动端其他部分适配 */
@media (max-width: 768px) {
    .hero-content {
        padding: 2rem 1.25rem;
        text-align: center;
    }

    .hero-content h1 {
        font-size: 2rem;
        line-height: 1.2;
    }

    .hero-content p {
        font-size: 1.125rem;
    }

    .cta-buttons {
        flex-direction: column;
        gap: 1rem;
    }

    .primary-btn, .secondary-btn {
        width: 100%;
        text-align: center;
    }

    .savings-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
        padding: 1.25rem;
    }

    .features-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
        padding: 1.25rem;
    }

    .solutions-container {
        grid-template-columns: 1fr;
        gap: 1.5rem;
        padding: 1.25rem;
    }

    .testimonials-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
        padding: 1.25rem;
    }
}

/* 主横幅样式 */
.hero {
    padding: 8rem 1rem 4rem;
    background: linear-gradient(135deg, #1a237e, #0d47a1);
    color: white;
    text-align: center;
}

.hero-content {
    max-width: var(--max-width);
    margin: 0 auto;
}

.hero h1 {
    font-size: 3.5rem;
    margin-bottom: 1rem;
    font-weight: 800;
}

.hero p {
    font-size: 1.25rem;
    margin-bottom: 2rem;
    opacity: 0.9;
}

/* 节省部分样式 */
.savings {
    padding: 4rem 1rem;
    background: var(--light-background);
    text-align: center;
}

.savings h2 {
    font-size: 2rem;
    max-width: 800px;
    margin: 0 auto 2rem;
}

.savings .subtitle {
    color: var(--light-text);
    margin-bottom: 3rem;
}

.savings-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    max-width: var(--max-width);
    margin: 0 auto 3rem;
}

.savings-card {
    background: white;
    padding: 2rem;
    border-radius: 0.5rem;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

.savings-card h3 {
    font-size: 3rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.savings-card .highlight {
    font-size: 1.1rem;
    font-weight: 500;
}

.savings-disclaimer {
    font-size: 0.875rem;
    color: var(--light-text);
    max-width: 800px;
    margin: 0 auto;
    text-align: left;
}

.savings-disclaimer p {
    margin-bottom: 0.5rem;
}

/* 功能部分样式 */
.features {
    padding: 4rem 1rem;
}

.features h2 {
    text-align: center;
    margin-bottom: 3rem;
    font-size: 2.5rem;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    max-width: var(--max-width);
    margin: 0 auto;
}

.feature-card {
    background: white;
    padding: 2rem;
    border-radius: 0.5rem;
    text-align: center;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    transition: transform 0.3s;
}

.feature-card:hover {
    transform: translateY(-5px);
}

.feature-card i {
    font-size: 2rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

/* 解决方案样式 */
.solutions {
    padding: 4rem 1rem;
    background: var(--light-background);
}

.solutions h2 {
    text-align: center;
    margin-bottom: 3rem;
    font-size: 2.5rem;
}

.solutions-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    max-width: var(--max-width);
    margin: 0 auto;
}

.solution-card {
    background: white;
    padding: 2rem;
    border-radius: 0.5rem;
    text-align: left;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

.solution-card h3 {
    margin-bottom: 1rem;
    font-size: 1.5rem;
}

.solution-btn {
    display: inline-block;
    margin-top: 1.5rem;
    padding: 0.75rem 1.5rem;
    background: var(--primary-color);
    color: white;
    text-decoration: none;
    border-radius: 0.375rem;
    transition: background-color 0.3s;
}

.solution-btn:hover {
    background: var(--secondary-color);
}

.api-note {
    text-align: center;
    margin-top: 2rem;
}

.api-note a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
}

/* 合作伙伴部分样式 */
.partners {
    padding: 4rem 1rem;
    text-align: center;
}

.partners h2 {
    font-size: 2rem;
    margin-bottom: 1rem;
}

.partners h3 {
    color: var(--light-text);
    margin-bottom: 3rem;
}

.partner-logos {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 2rem;
    align-items: center;
    justify-items: center;
    margin: 2rem auto;
    max-width: 1200px;
    padding: 0 1rem;
}

.partner-logos img {
    max-width: 150px;
    height: auto;
    transition: transform 0.3s ease;
}

.partner-logos img:hover {
    transform: scale(1.05);
}

@media screen and (max-width: 768px) {
    .partner-logos {
        grid-template-columns: 1fr;
        gap: 3rem;
        padding: 0 2rem;
    }

    .partner-logos img {
        max-width: 200px;
        margin: 0 auto;
    }
}

/* 推荐部分样式 */
.testimonials {
    padding: 4rem 1rem;
    background: var(--light-background);
}

.testimonials h2 {
    text-align: center;
    margin-bottom: 3rem;
    font-size: 2rem;
}

.testimonials-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    max-width: var(--max-width);
    margin: 0 auto;
}

.testimonial-card {
    background: white;
    padding: 2rem;
    border-radius: 0.5rem;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

.testimonial-content p {
    font-style: italic;
    margin-bottom: 1.5rem;
}

.testimonial-author h4 {
    color: var(--primary-color);
    margin-bottom: 0.25rem;
}

.testimonial-author p {
    color: var(--light-text);
    font-size: 0.875rem;
}

/* 页脚样式 */
.footer {
    background: var(--text-color);
    color: white;
    padding: 4rem 1rem 2rem;
}

.footer-content {
    max-width: var(--max-width);
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 3rem;
}

.footer-section h4 {
    font-size: 1.1rem;
    margin-bottom: 1.5rem;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 0.75rem;
}

.footer-section a {
    color: white;
    text-decoration: none;
    opacity: 0.8;
    transition: opacity 0.3s;
}

.footer-section a:hover {
    opacity: 1;
}

.footer-bottom {
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 1px solid rgba(255,255,255,0.1);
    text-align: center;
}

.footer-logos {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-logo, .pb-logo {
    height: 40px;
    width: auto;
}

.social-links {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
    margin-top: 1.5rem;
}

.social-links a {
    color: white;
    font-size: 1.5rem;
    opacity: 0.8;
    transition: opacity 0.3s;
}

.social-links a:hover {
    opacity: 1;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .nav-menu {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: white;
        padding: 1rem;
        flex-direction: column;
        align-items: flex-start;
        box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    }

    .nav-menu.active {
        display: flex;
    }

    .mobile-menu-btn {
        display: flex;
    }

    .hero h1 {
        font-size: 2.5rem;
    }

    .cta-buttons {
        flex-direction: column;
        gap: 1rem;
    }

    .savings-grid,
    .features-grid,
    .solutions-container,
    .testimonials-grid {
        grid-template-columns: 1fr;
    }

    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
}

/* 动画效果 */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.feature-card,
.solution-card,
.testimonial-card {
    animation: fadeIn 0.5s ease-out forwards;
}

/* Language Selector */
.language-selector {
    margin-left: 20px;
}

.language-selector .current-lang {
    display: flex;
    align-items: center;
    padding: 8px 15px;
    font-weight: 500;
}

.language-selector .dropdown-content {
    min-width: 100px;
    text-align: center;
}

.language-selector .dropdown-content a {
    padding: 8px 15px;
}

@media (max-width: 768px) {
    .language-selector {
        margin: 10px 0;
    }
    
    .language-selector .dropdown-content {
        position: static;
        display: block;
        background: none;
        box-shadow: none;
    }
}

/* 页脚移动端适配 */
@media (max-width: 768px) {
    .footer-nav {
        grid-template-columns: 1fr;
        gap: 2rem;
        text-align: center;
    }

    .footer-nav .nav-group {
        display: none !important; /* 强制隐藏所有导航组 */
    }

    .footer-bottom {
        margin-top: 0;
        padding-top: 2rem;
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }

    .footer-links {
        flex-direction: column;
        gap: 0.5rem;
    }
}