/* ============================================
   BinDown 品牌样式表
   ============================================ */

/* 品牌色板 */
:root {
    --primary-color: #f0b90b;
    --primary-dark: #d4a409;
    --secondary-color: #1e2329;
    --accent-color: #0ecb81;
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --bg-dark: #1e2329;
    --text-primary: #1e2329;
    --text-secondary: #666;
    --text-light: #999;
    --border-color: #e5e5e5;
    --gradient-primary: linear-gradient(135deg, #f0b90b, #d4a409);
    --gradient-dark: linear-gradient(135deg, #1e2329, #2d3339);
    --shadow-sm: 0 2px 8px rgba(0,0,0,0.06);
    --shadow-md: 0 4px 20px rgba(0,0,0,0.1);
    --shadow-lg: 0 8px 40px rgba(0,0,0,0.15);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* 重置样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    font-weight: 400;
    font-size: 16px;
    line-height: 1.6;
    color: var(--text-primary);
    background: var(--bg-primary);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* 容器 */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 导航栏 */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255,255,255,0.95);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(0,0,0,0.06);
    transition: var(--transition);
}

.navbar.scrolled {
    box-shadow: var(--shadow-md);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 70px;
}

.nav-left {
    display: flex;
    align-items: center;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
}

.logo-icon {
    width: 36px;
    height: 36px;
}

.logo-text {
    font-size: 22px;
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: -0.5px;
}

.nav-center {
    display: flex;
    align-items: center;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 8px;
}

.nav-links li a {
    padding: 8px 20px;
    text-decoration: none;
    color: var(--text-secondary);
    font-weight: 500;
    font-size: 15px;
    border-radius: var(--radius-sm);
    transition: var(--transition);
    position: relative;
}

.nav-links li a:hover,
.nav-links li a.active {
    color: var(--primary-color);
    background: rgba(240,185,11,0.08);
}

.nav-links li a.active::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 50%;
    transform: translateX(-50%);
    width: 20px;
    height: 3px;
    background: var(--primary-color);
    border-radius: 2px;
}

.nav-right {
    display: flex;
    align-items: center;
    gap: 15px;
}

/* 按钮样式 */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 10px 24px;
    border: 2px solid transparent;
    border-radius: var(--radius-sm);
    font-size: 15px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    text-decoration: none;
    white-space: nowrap;
}

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

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 20px rgba(240,185,11,0.3);
}

.btn-outline {
    background: transparent;
    color: var(--primary-color);
    border-color: var(--primary-color);
}

.btn-outline:hover {
    background: var(--primary-color);
    color: var(--secondary-color);
    transform: translateY(-2px);
}

.btn-lg {
    padding: 14px 32px;
    font-size: 16px;
    border-radius: var(--radius-md);
}

/* 汉堡菜单 */
.hamburger {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
}

.hamburger span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--text-primary);
    border-radius: 2px;
    transition: var(--transition);
}

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

.hamburger.active span:nth-child(2) {
    opacity: 0;
}

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

/* Hero区 */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding: 120px 0 80px;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, rgba(240,185,11,0.05) 0%, rgba(30,35,41,0.02) 50%, rgba(240,185,11,0.03) 100%);
    z-index: 0;
}

.hero-bg::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -20%;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(240,185,11,0.08) 0%, transparent 70%);
    border-radius: 50%;
    animation: float 20s infinite ease-in-out;
}

.hero-bg::after {
    content: '';
    position: absolute;
    bottom: -30%;
    left: -10%;
    width: 400px;
    height: 400px;
    background: radial-gradient(circle, rgba(14,203,129,0.06) 0%, transparent 70%);
    border-radius: 50%;
    animation: float 25s infinite ease-in-out reverse;
}

@keyframes float {
    0%, 100% { transform: translate(0, 0) scale(1); }
    33% { transform: translate(30px, -30px) scale(1.1); }
    66% { transform: translate(-20px, 20px) scale(0.9); }
}

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
}

.hero-logo {
    height: 60px;
    margin-bottom: 30px;
    animation: fadeInUp 0.8s ease;
}

.hero-title {
    font-size: 48px;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 24px;
    color: var(--text-primary);
    animation: fadeInUp 0.8s ease 0.1s both;
}

.highlight {
    color: var(--primary-color);
    position: relative;
}

.highlight::after {
    content: '';
    position: absolute;
    bottom: 2px;
    left: 0;
    right: 0;
    height: 8px;
    background: rgba(240,185,11,0.2);
    border-radius: 4px;
    z-index: -1;
}

.hero-subtitle {
    font-size: 18px;
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: 40px;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
    animation: fadeInUp 0.8s ease 0.2s both;
}

.hero-actions {
    display: flex;
    gap: 16px;
    justify-content: center;
    margin-bottom: 60px;
    animation: fadeInUp 0.8s ease 0.3s both;
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: 40px;
    animation: fadeInUp 0.8s ease 0.4s both;
}

.stat-item {
    text-align: center;
}

.stat-number {
    display: block;
    font-size: 32px;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 4px;
}

.stat-label {
    font-size: 14px;
    color: var(--text-secondary);
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* 通用section样式 */
section {
    padding: 100px 0;
}

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

.section-title {
    font-size: 36px;
    font-weight: 700;
    margin-bottom: 16px;
    color: var(--text-primary);
}

.section-desc {
    font-size: 16px;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
    line-height: 1.8;
}

/* 特色服务 */
.features {
    background: var(--bg-secondary);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 24px;
}

.feature-card {
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    padding: 32px;
    text-align: center;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

.feature-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-color);
}

.feature-icon {
    width: 64px;
    height: 64px;
    background: var(--gradient-primary);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 20px;
    font-size: 28px;
    color: var(--secondary-color);
}

.feature-card h3 {
    font-size: 20px;
    font-weight: 600;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.feature-card p {
    font-size: 15px;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* 下载中心 */
.download-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 24px;
}

.download-card {
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    padding: 32px;
    text-align: center;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

.download-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
}

.download-icon {
    width: 72px;
    height: 72px;
    background: var(--gradient-dark);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 20px;
    font-size: 32px;
    color: var(--primary-color);
}

.download-card h3 {
    font-size: 20px;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.download-card p {
    font-size: 14px;
    color: var(--text-secondary);
    margin-bottom: 16px;
}

.download-info {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-bottom: 20px;
    font-size: 13px;
    color: var(--text-light);
}

.download-btn {
    width: 100%;
}

/* 安全认证 */
.security {
    background: var(--bg-secondary);
}

.security-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 24px;
}

.security-card {
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    padding: 32px;
    text-align: center;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

.security-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.security-icon {
    width: 56px;
    height: 56px;
    background: linear-gradient(135deg, var(--accent-color), #06b87a);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 16px;
    font-size: 24px;
    color: #fff;
}

.security-card h3 {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.security-card p {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* 合作伙伴 */
.partners-grid {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 30px;
}

.partner-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 16px 32px;
    background: var(--bg-primary);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
    transition: var(--transition);
    font-size: 16px;
    font-weight: 500;
    color: var(--text-secondary);
}

.partner-item:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
    border-color: var(--primary-color);
    color: var(--primary-color);
}

.partner-item i {
    font-size: 24px;
    color: var(--primary-color);
}

/* 用户评价 */
.testimonials {
    background: var(--bg-secondary);
}

.testimonials-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 24px;
}

.testimonial-card {
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    padding: 32px;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

.testimonial-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.testimonial-stars {
    color: var(--primary-color);
    font-size: 16px;
    margin-bottom: 16px;
}

.testimonial-text {
    font-size: 15px;
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: 20px;
    font-style: italic;
}

.testimonial-author {
    display: flex;
    align-items: center;
    gap: 12px;
}

.author-avatar {
    width: 44px;
    height: 44px;
    background: var(--gradient-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--secondary-color);
    font-weight: 700;
    font-size: 18px;
}

.author-info {
    display: flex;
    flex-direction: column;
}

.author-name {
    font-weight: 600;
    font-size: 15px;
    color: var(--text-primary);
}

.author-title {
    font-size: 13px;
    color: var(--text-light);
}

/* 页脚 */
.footer {
    background: var(--secondary-color);
    color: #fff;
    padding: 80px 0 0;
}

.footer-content {
    display: grid;
    grid-template-columns: 1.5fr 2fr;
    gap: 60px;
    margin-bottom: 40px;
}

.footer-logo {
    height: 44px;
    margin-bottom: 20px;
}

.footer-desc {
    font-size: 14px;
    color: rgba(255,255,255,0.6);
    line-height: 1.8;
    margin-bottom: 24px;
}

.footer-social {
    display: flex;
    gap: 12px;
}

.social-link {
    width: 40px;
    height: 40px;
    background: rgba(255,255,255,0.1);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: rgba(255,255,255,0.7);
    text-decoration: none;
    transition: var(--transition);
    font-size: 18px;
}

.social-link:hover {
    background: var(--primary-color);
    color: var(--secondary-color);
    transform: translateY(-3px);
}

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

.footer-column h4 {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 20px;
    color: #fff;
}

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

.footer-column ul li {
    margin-bottom: 10px;
}

.footer-column ul li a {
    color: rgba(255,255,255,0.6);
    text-decoration: none;
    font-size: 14px;
    transition: var(--transition);
}

.footer-column ul li a:hover {
    color: var(--primary-color);
    padding-left: 4px;
}

.footer-bottom {
    border-top: 1px solid rgba(255,255,255,0.1);
    padding: 24px 0;
    text-align: center;
}

.footer-bottom p {
    font-size: 13px;
    color: rgba(255,255,255,0.5);
}

.footer-bottom a {
    color: rgba(255,255,255,0.7);
    text-decoration: none;
    transition: var(--transition);
}

.footer-bottom a:hover {
    color: var(--primary-color);
}

/* 页面标题（内页） */
.page-hero {
    padding: 140px 0 60px;
    text-align: center;
    background: linear-gradient(135deg, rgba(240,185,11,0.05), rgba(30,35,41,0.02));
}

.page-title {
    font-size: 42px;
    font-weight: 700;
    margin-bottom: 12px;
}

.page-desc {
    font-size: 18px;
    color: var(--text-secondary);
}

/* 品牌故事 */
.story-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.story-text h2 {
    font-size: 32px;
    font-weight: 700;
    margin-bottom: 24px;
}

.story-text p {
    font-size: 16px;
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: 16px;
}

.story-image {
    display: flex;
    align-items: center;
    justify-content: center;
}

.story-icon {
    width: 200px;
    height: 200px;
    background: var(--gradient-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 80px;
    color: var(--secondary-color);
    box-shadow: var(--shadow-lg);
    animation: float 6s infinite ease-in-out;
}

/* 发展历程 */
.timeline {
    background: var(--bg-secondary);
}

.timeline-grid {
    max-width: 700px;
    margin: 0 auto;
    position: relative;
}

.timeline-grid::before {
    content: '';
    position: absolute;
    left: 20px;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--primary-color);
    opacity: 0.3;
}

.timeline-item {
    position: relative;
    padding-left: 60px;
    padding-bottom: 40px;
}

.timeline-item:last-child {
    padding-bottom: 0;
}

.timeline-dot {
    position: absolute;
    left: 12px;
    top: 4px;
    width: 18px;
    height: 18px;
    background: var(--primary-color);
    border-radius: 50%;
    border: 4px solid var(--bg-secondary);
    box-shadow: 0 0 0 2px var(--primary-color);
}

.timeline-content {
    background: var(--bg-primary);
    padding: 24px;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
    transition: var(--transition);
}

.timeline-content:hover {
    transform: translateX(4px);
    box-shadow: var(--shadow-md);
}

.timeline-year {
    display: inline-block;
    padding: 4px 12px;
    background: var(--gradient-primary);
    color: var(--secondary-color);
    border-radius: 20px;
    font-size: 13px;
    font-weight: 600;
    margin-bottom: 8px;
}

.timeline-content h3 {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.timeline-content p {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* 团队 */
.team-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 24px;
    margin-top: 40px;
}

.team-card {
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    padding: 32px;
    text-align: center;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
    transition: var(--transition);
}

.team-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
}

.team-avatar {
    width: 80px;
    height: 80px;
    background: var(--gradient-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 16px;
    font-size: 32px;
    color: var(--secondary-color);
    font-weight: 700;
}

.team-card h3 {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 4px;
    color: var(--text-primary);
}

.team-card .team-role {
    font-size: 14px;
    color: var(--primary-color);
    font-weight: 500;
    margin-bottom: 12px;
}

.team-card p {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* 使命愿景 */
.mission {
    background: var(--bg-secondary);
}

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

.mission-card {
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    padding: 40px 32px;
    text-align: center;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
    transition: var(--transition);
}

.mission-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.mission-icon {
    width: 64px;
    height: 64px;
    background: var(--gradient-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 20px;
    font-size: 28px;
    color: var(--secondary-color);
}

.mission-card h3 {
    font-size: 20px;
    font-weight: 600;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.mission-card p {
    font-size: 15px;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* 联系页面 */
.contact-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 24px;
    margin-bottom: 60px;
}

.contact-card {
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    padding: 32px;
    text-align: center;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
    transition: var(--transition);
}

.contact-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.contact-icon {
    width: 56px;
    height: 56px;
    background: var(--gradient-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 16px;
    font-size: 24px;
    color: var(--secondary-color);
}

.contact-card h3 {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.contact-card p {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* 留言表单 */
.contact-form-section {
    background: var(--bg-secondary);
}

.form-container {
    max-width: 700px;
    margin: 0 auto;
    background: var(--bg-primary);
    border-radius: var(--radius-xl);
    padding: 48px;
    box-shadow: var(--shadow-md);
}

.form-container h2 {
    font-size: 28px;
    font-weight: 700;
    margin-bottom: 8px;
    text-align: center;
}

.form-container > p {
    text-align: center;
    color: var(--text-secondary);
    margin-bottom: 32px;
}

.contact-form {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

.form-group {
    margin-bottom: 0;
}

.form-group.full-width {
    grid-column: 1 / -1;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    font-size: 14px;
    color: var(--text-primary);
}

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 12px 16px;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-sm);
    font-size: 15px;
    font-family: inherit;
    transition: var(--transition);
    background: var(--bg-primary);
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 4px rgba(240,185,11,0.1);
}

.form-group textarea {
    resize: vertical;
    min-height: 120px;
}

.form-group select {
    cursor: pointer;
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%23666' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 12px center;
    padding-right: 36px;
}

/* 社交媒体区域 */
.social-section {
    background: var(--bg-primary);
}

.social-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 20px;
    max-width: 700px;
    margin: 0 auto;
}

.social-card {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
    padding: 20px;
    background: var(--bg-secondary);
    border-radius: var(--radius-md);
    text-decoration: none;
    color: var(--text-primary);
    font-weight: 500;
    font-size: 15px;
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

.social-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
    border-color: var(--primary-color);
    color: var(--primary-color);
}

.social-card i {
    font-size: 24px;
    color: var(--primary-color);
}

/* 响应式设计 */
@media (max-width: 1024px) {
    .footer-content {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    
    .footer-links {
        grid-template-columns: repeat(3, 1fr);
    }
    
    .mission-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    .nav-center {
        display: none;
    }
    
    .nav-center.active {
        display: flex;
        position: absolute;
        top: 70px;
        left: 0;
        right: 0;
        background: rgba(255,255,255,0.98);
        backdrop-filter: blur(20px);
        border-bottom: 1px solid var(--border-color);
        padding: 20px;
        flex-direction: column;
    }
    
    .nav-links {
        flex-direction: column;
        gap: 4px;
    }
    
    .nav-links li a {
        padding: 12px 16px;
        display: block;
        text-align: center;
    }
    
    .nav-links li a.active::after {
        display: none;
    }
    
    .hamburger {
        display: flex;
    }
    
    .nav-cta {
        display: none;
    }
    
    .hero-title {
        font-size: 32px;
    }
    
    .hero-subtitle {
        font-size: 16px;
    }
    
    .hero-actions {
        flex-direction: column;
        align-items: center;
    }
    
    .hero-stats {
        flex-wrap: wrap;
        gap: 20px;
    }
    
    .stat-number {
        font-size: 24px;
    }
    
    .section-title {
        font-size: 28px;
    }
    
    .story-content {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    
    .story-image {
        order: -1;
    }
    
    .story-icon {
        width: 150px;
        height: 150px;
        font-size: 60px;
    }
    
    .contact-form {
        grid-template-columns: 1fr;
    }
    
    .form-container {
        padding: 32px 24px;
    }
    
    .footer-links {
        grid-template-columns: 1fr;
        gap: 30px;
    }
    
    .page-title {
        font-size: 32px;
    }
    
    .social-card {
        padding: 16px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 16px;
    }
    
    .hero {
        padding: 100px 0 60px;
    }
    
    .hero-title {
        font-size: 28px;
    }
    
    .hero-logo {
        height: 44px;
    }
    
    section {
        padding: 60px 0;
    }
    
    .section-header {
        margin-bottom: 40px;
    }
    
    .section-title {
        font-size: 24px;
    }
    
    .features-grid,
    .download-grid,
    .security-grid,
    .testimonials-grid,
    .team-grid {
        grid-template-columns: 1fr;
    }
    
    .timeline-item {
        padding-left: 50px;
    }
    
    .timeline-dot {
        left: 6px;
    }
}

/* 成功提示 */
.success-message {
    text-align: center;
    padding: 40px 20px;
}

.success-message i {
    font-size: 48px;
    color: var(--accent-color);
    margin-bottom: 16px;
}

.success-message h3 {
    font-size: 20px;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.success-message p {
    font-size: 15px;
    color: var(--text-secondary);
}