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

:root {
    /* 主题色 */
    --primary-color: #007AFF;
    --primary-dark: #0051D5;

    /* 文字颜色 */
    --text-primary: #1D1D1F;
    --text-secondary: #86868B;

    /* 背景色 */
    --background: #FFFFFF;
    --background-alt: #FBFBFD;

    /* 边框 */
    --border-color: rgba(0, 0, 0, 0.08);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text", "PingFang SC", "Hiragino Sans GB", sans-serif;
    line-height: 1.47059;
    letter-spacing: -0.022em;
    color: var(--text-primary);
    background-color: var(--background);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.container {
    max-width: 980px;
    margin: 0 auto;
    padding: 0 22px;
}

/* 导航栏 */
.navbar {
    position: sticky;
    top: 0;
    background: rgba(255, 255, 255, 0.72);
    backdrop-filter: saturate(180%) blur(20px);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 48px;
    max-width: 100%;
    padding: 0 22px;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 21px;
    font-weight: 600;
    letter-spacing: -0.022em;
    color: var(--text-primary);
    text-decoration: none;
}

.nav-logo {
    width: 28px;
    height: 28px;
    border-radius: 6px;
}

.logo {
    font-size: 28px;
}

.brand-name {
    color: var(--text-primary);
}

.nav-links {
    display: flex;
    gap: 32px;
}

.nav-links a {
    color: var(--text-primary);
    text-decoration: none;
    font-size: 12px;
    font-weight: 400;
    letter-spacing: -0.01em;
    opacity: 0.8;
    transition: opacity 0.3s;
}

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

/* Hero Section */
.hero {
    padding: 76px 0 92px;
    background: var(--background);
    text-align: center;
}

.hero-content {
    max-width: 692px;
    margin: 0 auto;
}

.hero-logo {
    width: 120px;
    height: 120px;
    border-radius: 28px;
    margin-bottom: 32px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
}

.hero-title {
    font-size: 80px;
    font-weight: 600;
    line-height: 1.05;
    letter-spacing: -0.015em;
    margin-bottom: 20px;
    color: var(--text-primary);
    white-space: nowrap;
}

.hero-subtitle {
    font-size: 28px;
    font-weight: 400;
    line-height: 1.14286;
    letter-spacing: 0.007em;
    color: var(--text-secondary);
    margin-bottom: 40px;
}

.hero-buttons {
    display: flex;
    gap: 16px;
    justify-content: center;
    margin-bottom: 16px;
    flex-wrap: wrap;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 12px 22px;
    border-radius: 980px;
    font-size: 17px;
    font-weight: 400;
    text-decoration: none;
    transition: all 0.2s cubic-bezier(0.4, 0, 0.6, 1);
    letter-spacing: -0.022em;
    white-space: nowrap;
}

.btn-primary {
    background: var(--primary-color);
    color: white;
}

.btn-primary:hover {
    background: var(--primary-dark);
}

.btn-secondary {
    background: transparent;
    color: var(--primary-color);
    border: 1px solid var(--primary-color);
}

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

.hero-badges {
    display: flex;
    gap: 24px;
    justify-content: center;
    flex-wrap: wrap;
}

.badge {
    padding: 0;
    background: transparent;
    border: none;
    font-size: 17px;
    font-weight: 400;
    color: var(--text-secondary);
    letter-spacing: -0.022em;
}

/* 理念区域 */
.philosophy {
    padding: 92px 0;
    background: var(--background-alt);
}

.philosophy-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

.philosophy-item {
    text-align: center;
    padding: 48px 24px;
    background: white;
    border-radius: 18px;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.6, 1);
}

.philosophy-item:hover {
    transform: scale(1.01);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
}

.philosophy-icon {
    width: 48px;
    height: 48px;
    color: var(--primary-color);
    margin-bottom: 16px;
    stroke-width: 1.5;
}

.philosophy-item h3 {
    font-size: 24px;
    font-weight: 600;
    line-height: 1.16667;
    letter-spacing: 0.009em;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.philosophy-item p {
    font-size: 17px;
    font-weight: 400;
    line-height: 1.47059;
    letter-spacing: -0.022em;
    color: var(--text-secondary);
}

.philosophy-content {
    text-align: center;
}

.philosophy-title {
    font-size: 56px;
    font-weight: 600;
    line-height: 1.07143;
    letter-spacing: -0.005em;
    margin-bottom: 16px;
    color: var(--text-primary);
}

.philosophy-text {
    font-size: 21px;
    font-weight: 400;
    line-height: 1.381;
    letter-spacing: 0.011em;
    color: var(--text-secondary);
    margin-bottom: 60px;
    max-width: 692px;
    margin-left: auto;
    margin-right: auto;
}

.philosophy-text strong {
    color: var(--text-primary);
    font-weight: 600;
}

.philosophy-cards {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

.philosophy-card {
    padding: 48px 24px;
    background: white;
    border-radius: 18px;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.6, 1);
    text-align: center;
}

.philosophy-card:hover {
    transform: scale(1.01);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
}

.philosophy-card-icon {
    font-size: 64px;
    margin-bottom: 16px;
}

.philosophy-card h3 {
    font-size: 24px;
    font-weight: 600;
    line-height: 1.16667;
    letter-spacing: 0.009em;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.philosophy-card p {
    font-size: 17px;
    font-weight: 400;
    line-height: 1.47059;
    letter-spacing: -0.022em;
    color: var(--text-secondary);
}

/* Section Title */
.section-title {
    font-size: 56px;
    font-weight: 600;
    line-height: 1.07143;
    letter-spacing: -0.005em;
    text-align: center;
    margin-bottom: 60px;
    color: var(--text-primary);
}

/* 功能特性 */
.features {
    padding: 92px 0;
    background: white;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 40px 24px;
}

.feature-card {
    text-align: center;
    padding: 24px 12px;
}

.feature-icon {
    font-size: 56px;
    margin-bottom: 16px;
}

.feature-card h3 {
    font-size: 21px;
    font-weight: 600;
    line-height: 1.381;
    letter-spacing: 0.011em;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.feature-card p {
    font-size: 17px;
    font-weight: 400;
    line-height: 1.47059;
    letter-spacing: -0.022em;
    color: var(--text-secondary);
}

/* 平台支持 */
.platforms {
    padding: 92px 0;
    background: var(--background-alt);
}

.platforms-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.platform-card {
    padding: 48px 40px;
    background: white;
    border-radius: 18px;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.6, 1);
}

.platform-card:hover {
    transform: scale(1.01);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
}

.platform-icon {
    width: 48px;
    height: 48px;
    color: var(--primary-color);
    margin-bottom: 20px;
    stroke-width: 1.5;
}

.platform-card h3 {
    font-size: 28px;
    font-weight: 600;
    line-height: 1.14286;
    letter-spacing: 0.007em;
    margin-bottom: 24px;
    color: var(--text-primary);
}

.platform-list {
    list-style: none;
    margin-bottom: 28px;
}

.platform-list li {
    padding: 6px 0;
    font-size: 17px;
    font-weight: 400;
    line-height: 1.47059;
    letter-spacing: -0.022em;
    color: var(--text-secondary);
}

.platform-features {
    list-style: none;
    margin-bottom: 28px;
}

.platform-features li {
    padding: 6px 0;
    font-size: 17px;
    font-weight: 400;
    line-height: 1.47059;
    letter-spacing: -0.022em;
    color: var(--text-secondary);
}

.platform-link {
    display: inline-block;
    color: var(--primary-color);
    text-decoration: none;
    font-size: 17px;
    font-weight: 400;
    letter-spacing: -0.022em;
    transition: opacity 0.3s;
}

.platform-link:hover {
    opacity: 0.7;
}

/* 隐私区域 */
.privacy {
    padding: 92px 0;
    background: var(--background-alt);
}

.privacy-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
}

.privacy-card {
    text-align: center;
    padding: 32px 20px;
    background: white;
    border-radius: 18px;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.6, 1);
    border: 1px solid var(--border-color);
}

.privacy-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    border-color: transparent;
}

.privacy-icon {
    width: 32px;
    height: 32px;
    color: var(--primary-color);
    margin-bottom: 16px;
    stroke-width: 1.5;
}

.privacy-card h3 {
    font-size: 17px;
    font-weight: 600;
    line-height: 1.47059;
    letter-spacing: -0.022em;
    color: var(--text-primary);
}

.link {
    color: var(--primary-color);
    text-decoration: none;
    font-size: 17px;
    font-weight: 400;
    letter-spacing: -0.022em;
    transition: opacity 0.3s;
}

.link:hover {
    opacity: 0.7;
}

/* FAQ */
.faq {
    padding: 92px 0;
    background: var(--background-alt);
}

.faq-list {
    max-width: 692px;
    margin: 0 auto;
}

.faq-item {
    padding: 32px 0;
    border-bottom: 1px solid var(--border-color);
}

.faq-item:last-child {
    border-bottom: none;
}

.faq-header {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 12px;
}

.faq-icon {
    width: 24px;
    height: 24px;
    color: var(--primary-color);
    stroke-width: 1.5;
    flex-shrink: 0;
}

.faq-item h3 {
    font-size: 21px;
    font-weight: 600;
    line-height: 1.381;
    letter-spacing: 0.011em;
    color: var(--text-primary);
    margin: 0;
}

.faq-item p {
    font-size: 17px;
    font-weight: 400;
    line-height: 1.47059;
    letter-spacing: -0.022em;
    color: var(--text-secondary);
    padding-left: 36px;
}

/* 联系方式 */
.contact {
    padding: 48px 0;
    background: white;
}

.contact-grid {
    display: flex;
    gap: 32px;
    justify-content: center;
    flex-wrap: wrap;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 16px 32px;
    background: var(--background-alt);
    border-radius: 12px;
    text-decoration: none;
    color: var(--text-primary);
    font-weight: 500;
    transition: all 0.2s;
}

.contact-item:hover {
    background: #E8E8ED;
    transform: translateY(-2px);
}

.contact-icon {
    width: 20px;
    height: 20px;
    color: var(--primary-color);
    stroke-width: 1.5;
}

.contact-info {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.contact-item h4 {
    font-size: 12px;
    font-weight: 400;
    letter-spacing: -0.01em;
    margin-bottom: 4px;
    color: var(--text-secondary);
    text-transform: uppercase;
}

.contact-item a {
    color: var(--primary-color);
    text-decoration: none;
    font-size: 17px;
    font-weight: 400;
    letter-spacing: -0.022em;
    transition: opacity 0.3s;
}

.contact-item a:hover {
    opacity: 0.7;
}

/* Footer */
.footer {
    padding: 32px 0;
    background: var(--background-alt);
    border-top: 1px solid var(--border-color);
    text-align: center;
}

.footer .container {
    display: flex;
    flex-direction: column;
    gap: 12px;
    align-items: center;
}

.footer-links {
    display: flex;
    gap: 12px;
    align-items: center;
}

.footer-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 12px;
    font-weight: 400;
    letter-spacing: -0.01em;
    transition: opacity 0.3s;
}

.footer-links a:hover {
    opacity: 0.7;
}

.footer-links span {
    color: var(--text-secondary);
    font-size: 12px;
}

.footer p {
    color: var(--text-secondary);
    font-size: 12px;
    font-weight: 400;
    letter-spacing: -0.01em;
}

/* 响应式设计 */
@media (max-width: 1068px) {
    .container {
        max-width: 692px;
    }

    .hero-title {
        font-size: 64px;
    }

    .philosophy-grid {
        grid-template-columns: 1fr;
        gap: 12px;
    }

    .features-grid {
        grid-template-columns: 1fr;
        gap: 32px;
    }

    .platforms-grid {
        grid-template-columns: 1fr;
        gap: 12px;
    }

    .privacy-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 12px;
    }

    .contact-info {
        grid-template-columns: 1fr;
    }

    .contact-grid {
        flex-direction: column;
    }
}

@media (max-width: 735px) {
    .container {
        max-width: 87.5%;
    }

    .navbar .container {
        height: 48px;
    }

    .nav-links {
        gap: 20px;
    }

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

    .hero {
        padding: 48px 0 60px;
    }

    .hero-title {
        font-size: 48px;
        white-space: normal;
    }

    .hero-subtitle {
        font-size: 21px;
    }

    .hero-buttons {
        flex-direction: column;
        gap: 12px;
    }

    .btn {
        width: 100%;
        justify-content: center;
    }

    .section-title {
        font-size: 40px;
    }

    .philosophy,
    .features,
    .platforms,
    .privacy,
    .faq {
        padding: 60px 0;
    }

    .contact {
        padding: 36px 0;
    }

    .privacy-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 12px;
    }
}