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

:root {
    --primary-bg: #020617;
    --primary-blue: #2563EB;
    --primary-pink: #EC4899;
    --text-primary: #F9FAFB;
    --text-secondary: #9CA3AF;
    --text-muted: #6B7280;
    --card-bg: rgba(15, 23, 42, 0.8);
    --border-color: rgba(30, 64, 175, 0.3);
    --glow-blue: rgba(37, 99, 235, 0.5);
    --glow-pink: rgba(236, 72, 153, 0.5);
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--primary-bg);
    color: var(--text-primary);
    overflow-x: hidden;
    line-height: 1.6;
}

/* 粒子背景 */
#particles-bg {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    background: 
        radial-gradient(circle at top left, rgba(59, 130, 246, 0.15), transparent 50%),
        radial-gradient(circle at top right, rgba(236, 72, 153, 0.1), transparent 50%),
        radial-gradient(circle at bottom left, rgba(37, 99, 235, 0.1), transparent 50%),
        radial-gradient(circle at bottom right, rgba(236, 72, 153, 0.15), transparent 50%),
        var(--primary-bg);
}

#particles-bg::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: 
        radial-gradient(2px 2px at 20px 30px, rgba(255,255,255,0.3), transparent),
        radial-gradient(2px 2px at 40px 70px, rgba(255,255,255,0.2), transparent),
        radial-gradient(1px 1px at 90px 40px, rgba(255,255,255,0.4), transparent),
        radial-gradient(2px 2px at 130px 80px, rgba(255,255,255,0.2), transparent),
        radial-gradient(1px 1px at 160px 120px, rgba(255,255,255,0.3), transparent);
    background-size: 200px 200px;
    animation: particleFloat 20s linear infinite;
}

@keyframes particleFloat {
    0% { transform: translateY(0); }
    100% { transform: translateY(-200px); }
}

/* 导航栏 */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    padding: 1rem 2rem;
    background: rgba(2, 6, 23, 0.8);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

.nav-container {
    max-width: 1400px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.5rem;
    font-weight: 700;
}

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

.logo-icon img {
    border-radius: 12px;
}

@keyframes logoGlow {
    0%, 100% { filter: drop-shadow(0 0 5px var(--glow-blue)); }
    50% { filter: drop-shadow(0 0 15px var(--glow-pink)); }
}

.logo-text {
    background: linear-gradient(135deg, #fff, #94a3b8);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

.nav-links {
    display: flex;
    gap: 2rem;
}

.nav-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.95rem;
    font-weight: 500;
    transition: all 0.3s ease;
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--primary-blue), var(--primary-pink));
    transition: width 0.3s ease;
}

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

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

.nav-actions {
    display: flex;
    align-items: center;
    gap: 1rem;
}

/* 语言切换器 */
.lang-switcher {
    position: relative;
}

.lang-btn {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-primary);
    font-size: 0.9rem;
    cursor: pointer;
    transition: all 0.3s ease;
}

.lang-btn:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: var(--primary-blue);
}

.lang-arrow {
    width: 16px;
    height: 16px;
    stroke-width: 2;
    transition: transform 0.3s ease;
}

.lang-switcher:hover .lang-arrow {
    transform: rotate(180deg);
}

.lang-dropdown {
    position: absolute;
    top: 100%;
    right: 0;
    margin-top: 0.5rem;
    min-width: 140px;
    background: rgba(15, 23, 42, 0.95);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 0.5rem;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: all 0.3s ease;
    backdrop-filter: blur(20px);
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.3);
}

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

.lang-dropdown a {
    display: block;
    padding: 0.75rem 1rem;
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.9rem;
    border-radius: 8px;
    transition: all 0.2s ease;
}

.lang-dropdown a:hover {
    background: rgba(37, 99, 235, 0.2);
    color: var(--text-primary);
}

.nav-cta {
    padding: 0.75rem 1.5rem;
    background: linear-gradient(135deg, var(--primary-blue), var(--primary-pink));
    border: none;
    border-radius: 999px;
    color: white;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.nav-cta::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.3), transparent);
    transition: left 0.5s ease;
}

.nav-cta:hover::before {
    left: 100%;
}

.nav-cta:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 30px rgba(37, 99, 235, 0.4);
}

/* Hero区域 */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 8rem 4rem 4rem;
    max-width: 1400px;
    margin: 0 auto;
    gap: 4rem;
}

.hero-content {
    flex: 1;
    max-width: 600px;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background: rgba(37, 99, 235, 0.1);
    border: 1px solid var(--border-color);
    border-radius: 999px;
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    animation: fadeInUp 0.6s ease;
}

.badge-dot {
    width: 8px;
    height: 8px;
    background: #10B981;
    border-radius: 50%;
    animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; transform: scale(1); }
    50% { opacity: 0.5; transform: scale(1.2); }
}

.hero-title {
    font-size: 4rem;
    font-weight: 800;
    line-height: 1.1;
    margin-bottom: 1.5rem;
    animation: fadeInUp 0.6s ease 0.1s both;
}

.title-line {
    display: block;
}

.gradient-text {
    background: linear-gradient(135deg, var(--primary-blue), var(--primary-pink), #8B5CF6);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-size: 200% 200%;
    animation: gradientMove 3s ease infinite;
}

@keyframes gradientMove {
    0%, 100% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
}

.hero-desc {
    font-size: 1.2rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
    line-height: 1.8;
    animation: fadeInUp 0.6s ease 0.2s both;
}

.hero-actions {
    display: flex;
    gap: 1rem;
    margin-bottom: 3rem;
    animation: fadeInUp 0.6s ease 0.3s both;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 1rem 2rem;
    border-radius: 12px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    border: none;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-blue), var(--primary-pink));
    color: white;
    position: relative;
    overflow: hidden;
}

.btn-primary::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.3), transparent);
    transition: left 0.5s ease;
}

.btn-primary:hover::before {
    left: 100%;
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 15px 40px rgba(37, 99, 235, 0.5);
}

.btn-arrow {
    width: 20px;
    height: 20px;
    stroke-width: 2;
    transition: transform 0.3s ease;
}

.btn-primary:hover .btn-arrow {
    transform: translateX(5px);
}

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

.btn-secondary:hover {
    background: rgba(255,255,255,0.05);
    border-color: var(--primary-blue);
}

.hero-stats {
    display: flex;
    gap: 3rem;
    animation: fadeInUp 0.6s ease 0.4s both;
}

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

.stat-number {
    display: block;
    font-size: 2.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary-blue), var(--primary-pink));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.stat-label {
    font-size: 0.9rem;
    color: var(--text-muted);
}

/* Hero视觉区域 */
.hero-visual {
    flex: 1;
    position: relative;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 500px;
}

.phone-mockup {
    position: relative;
    z-index: 2;
}

.phone-frame {
    width: 280px;
    height: 580px;
    background: linear-gradient(145deg, #1a1a2e, #0f0f1a);
    border-radius: 40px;
    padding: 12px;
    box-shadow: 
        0 50px 100px rgba(0,0,0,0.5),
        inset 0 1px 0 rgba(255,255,255,0.1);
    animation: phoneFloat 6s ease-in-out infinite;
}

@keyframes phoneFloat {
    0%, 100% { transform: translateY(0) rotateY(-5deg); }
    50% { transform: translateY(-20px) rotateY(5deg); }
}

.phone-screen {
    width: 100%;
    height: 100%;
    background: var(--primary-bg);
    border-radius: 30px;
    overflow: hidden;
}

.chat-preview {
    height: 100%;
    display: flex;
    flex-direction: column;
}

.chat-header-mock {
    height: 60px;
    background: linear-gradient(135deg, rgba(37, 99, 235, 0.3), rgba(236, 72, 153, 0.3));
    border-bottom: 1px solid var(--border-color);
}

.chat-messages {
    flex: 1;
    padding: 1rem;
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.msg {
    display: flex;
    gap: 0.5rem;
    animation: msgSlide 0.5s ease both;
}

.msg-received {
    animation-delay: 0.5s;
}

.msg-sent {
    justify-content: flex-end;
    animation-delay: 1s;
}

.msg:nth-child(3) {
    animation-delay: 1.5s;
}

@keyframes msgSlide {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.msg-avatar {
    width: 32px;
    height: 32px;
    background: linear-gradient(135deg, var(--primary-blue), var(--primary-pink));
    border-radius: 50%;
    flex-shrink: 0;
}

.msg-bubble {
    height: 24px;
    width: 120px;
    background: rgba(255,255,255,0.1);
    border-radius: 12px;
}

.msg-sent .msg-bubble {
    background: linear-gradient(135deg, var(--primary-blue), var(--primary-pink));
    width: 80px;
}

.phone-glow {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 400px;
    height: 400px;
    background: radial-gradient(circle, rgba(37, 99, 235, 0.3), transparent 70%);
    filter: blur(40px);
    z-index: -1;
    animation: glowPulse 4s ease-in-out infinite;
}

@keyframes glowPulse {
    0%, 100% { opacity: 0.5; transform: translate(-50%, -50%) scale(1); }
    50% { opacity: 0.8; transform: translate(-50%, -50%) scale(1.1); }
}

/* 浮动元素 */
.floating-elements {
    position: absolute;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
    pointer-events: none;
}

.float-card {
    position: absolute;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1rem;
    background: rgba(15, 23, 42, 0.9);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    font-size: 0.85rem;
    backdrop-filter: blur(10px);
    animation: floatCard 6s ease-in-out infinite;
}

.float-icon {
    font-size: 1.2rem;
}

.float-card-1 {
    top: 10%;
    right: -20%;
    animation-delay: 0s;
}

.float-card-2 {
    top: 50%;
    left: -15%;
    animation-delay: 2s;
}

.float-card-3 {
    bottom: 15%;
    right: -25%;
    animation-delay: 4s;
}

@keyframes floatCard {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-15px); }
}

/* 功能特性区域 */
.features {
    padding: 8rem 4rem;
    max-width: 1400px;
    margin: 0 auto;
}

.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-tag {
    display: inline-block;
    padding: 0.5rem 1rem;
    background: linear-gradient(135deg, rgba(37, 99, 235, 0.1), rgba(236, 72, 153, 0.1));
    border: 1px solid var(--border-color);
    border-radius: 999px;
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

.section-title {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 1rem;
    background: linear-gradient(135deg, #fff, #94a3b8);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.section-desc {
    font-size: 1.2rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
}

.feature-card {
    position: relative;
    padding: 2rem;
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    transition: all 0.4s ease;
    overflow: hidden;
}

.feature-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, rgba(37, 99, 235, 0.1), rgba(236, 72, 153, 0.1));
    opacity: 0;
    transition: opacity 0.4s ease;
}

.feature-card:hover {
    transform: translateY(-10px);
    border-color: var(--primary-blue);
    box-shadow: 0 20px 50px rgba(37, 99, 235, 0.2);
}

.feature-card:hover::before {
    opacity: 1;
}

.feature-icon {
    width: 60px;
    height: 60px;
    margin-bottom: 1.5rem;
    padding: 1rem;
    background: linear-gradient(135deg, rgba(37, 99, 235, 0.2), rgba(236, 72, 153, 0.2));
    border-radius: 16px;
    position: relative;
    z-index: 1;
}

.feature-icon svg {
    width: 100%;
    height: 100%;
    stroke: var(--primary-blue);
    stroke-width: 1.5;
}

.feature-title {
    font-size: 1.3rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
    position: relative;
    z-index: 1;
}

.feature-desc {
    font-size: 0.95rem;
    color: var(--text-secondary);
    line-height: 1.7;
    position: relative;
    z-index: 1;
}

.feature-glow {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 200px;
    height: 200px;
    background: radial-gradient(circle, rgba(37, 99, 235, 0.2), transparent 70%);
    opacity: 0;
    transition: opacity 0.4s ease;
    pointer-events: none;
}

.feature-card:hover .feature-glow {
    opacity: 1;
}

/* 安全区域 */
.security {
    position: relative;
    padding: 8rem 4rem;
    overflow: hidden;
}

.security-bg {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 0;
}

.security-grid {
    width: 100%;
    height: 100%;
    background-image: 
        linear-gradient(rgba(37, 99, 235, 0.1) 1px, transparent 1px),
        linear-gradient(90deg, rgba(37, 99, 235, 0.1) 1px, transparent 1px);
    background-size: 50px 50px;
    animation: gridMove 20s linear infinite;
}

@keyframes gridMove {
    0% { transform: translate(0, 0); }
    100% { transform: translate(50px, 50px); }
}

.security-content {
    position: relative;
    z-index: 1;
    max-width: 1400px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.security-text .section-title {
    text-align: left;
}

.security-text .section-desc {
    text-align: left;
    margin: 0 0 2rem;
}

.security-features {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
}

.security-item {
    display: flex;
    gap: 1rem;
    padding: 1rem;
    background: rgba(15, 23, 42, 0.5);
    border-radius: 12px;
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

.security-item:hover {
    background: rgba(15, 23, 42, 0.8);
    border-color: var(--primary-blue);
}

.security-icon {
    font-size: 2rem;
}

.security-info h4 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 0.25rem;
}

.security-info p {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.security-visual {
    display: flex;
    justify-content: center;
    align-items: center;
}

.encryption-animation {
    position: relative;
    width: 300px;
    height: 300px;
}

.encrypt-ring {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    border-radius: 50%;
    border: 2px solid transparent;
    animation: ringRotate 10s linear infinite;
}

.ring-1 {
    width: 200px;
    height: 200px;
    border-color: rgba(37, 99, 235, 0.3);
    animation-duration: 8s;
}

.ring-2 {
    width: 250px;
    height: 250px;
    border-color: rgba(236, 72, 153, 0.3);
    animation-duration: 12s;
    animation-direction: reverse;
}

.ring-3 {
    width: 300px;
    height: 300px;
    border-color: rgba(139, 92, 246, 0.3);
    animation-duration: 15s;
}

@keyframes ringRotate {
    from { transform: translate(-50%, -50%) rotate(0deg); }
    to { transform: translate(-50%, -50%) rotate(360deg); }
}

.encrypt-core {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 120px;
    height: 120px;
    background: linear-gradient(135deg, var(--primary-blue), var(--primary-pink));
    border-radius: 50%;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    box-shadow: 
        0 0 60px rgba(37, 99, 235, 0.5),
        0 0 100px rgba(236, 72, 153, 0.3);
    animation: corePulse 3s ease-in-out infinite;
}

.encrypt-core span:first-child {
    font-size: 2.5rem;
    font-weight: 700;
}

.encrypt-core span:last-child {
    font-size: 1rem;
    color: rgba(255,255,255,0.8);
}

@keyframes corePulse {
    0%, 100% { transform: translate(-50%, -50%) scale(1); }
    50% { transform: translate(-50%, -50%) scale(1.05); }
}

/* 下载区域 */
.download {
    padding: 8rem 4rem;
    text-align: center;
    background: linear-gradient(180deg, transparent, rgba(37, 99, 235, 0.05));
}

.download-content {
    max-width: 800px;
    margin: 0 auto;
}

.download-buttons {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 1rem;
    margin: 3rem 0;
}

.download-btn {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem 1.5rem;
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    text-decoration: none;
    color: var(--text-primary);
    transition: all 0.3s ease;
}

.download-btn:hover {
    background: rgba(37, 99, 235, 0.1);
    border-color: var(--primary-blue);
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(37, 99, 235, 0.2);
}

.download-icon {
    width: 32px;
    height: 32px;
    fill: var(--text-primary);
}

.download-info {
    display: flex;
    flex-direction: column;
    text-align: left;
}

.download-label {
    font-size: 0.75rem;
    color: var(--text-muted);
}

.download-platform {
    font-size: 1.1rem;
    font-weight: 600;
}

.download-qr {
    margin-top: 2rem;
}

.qr-code {
    width: 150px;
    height: 150px;
    margin: 0 auto 1rem;
    background: white;
    border-radius: 12px;
    padding: 10px;
}

.qr-placeholder {
    width: 100%;
    height: 100%;
    background: 
        linear-gradient(45deg, #333 25%, transparent 25%),
        linear-gradient(-45deg, #333 25%, transparent 25%),
        linear-gradient(45deg, transparent 75%, #333 75%),
        linear-gradient(-45deg, transparent 75%, #333 75%);
    background-size: 20px 20px;
    background-position: 0 0, 0 10px, 10px -10px, -10px 0px;
    border-radius: 8px;
}

.download-qr p {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* 关于区域 */
.about {
    padding: 8rem 4rem;
    text-align: center;
}

.about-content {
    max-width: 800px;
    margin: 0 auto;
}

.about-stats {
    display: flex;
    justify-content: center;
    gap: 4rem;
    margin-top: 3rem;
}

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

.about-stat-number {
    display: block;
    font-size: 3rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary-blue), var(--primary-pink));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.about-stat-label {
    color: var(--text-secondary);
    font-size: 1rem;
}

/* 页脚 */
.footer {
    padding: 4rem 4rem 2rem;
    border-top: 1px solid var(--border-color);
    background: rgba(2, 6, 23, 0.9);
}

.footer-content {
    max-width: 1400px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 1fr 2fr 1fr;
    gap: 4rem;
    margin-bottom: 3rem;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

.footer-tagline {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: 4rem;
}

.footer-column h4 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.footer-column a {
    display: block;
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.9rem;
    margin-bottom: 0.5rem;
    transition: color 0.3s ease;
}

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

.footer-social {
    display: flex;
    gap: 1rem;
    justify-content: flex-end;
}

.social-link {
    padding: 0.5rem 1rem;
    background: rgba(255,255,255,0.05);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.85rem;
    transition: all 0.3s ease;
}

.social-link:hover {
    background: rgba(37, 99, 235, 0.1);
    border-color: var(--primary-blue);
    color: var(--text-primary);
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
}

.footer-bottom p {
    color: var(--text-muted);
    font-size: 0.85rem;
}

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

/* 响应式设计 */
@media (max-width: 1200px) {
    .hero {
        flex-direction: column;
        text-align: center;
        padding-top: 10rem;
    }
    
    .hero-content {
        max-width: 100%;
    }
    
    .hero-actions {
        justify-content: center;
    }
    
    .hero-stats {
        justify-content: center;
    }
    
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .security-content {
        grid-template-columns: 1fr;
    }
    
    .security-visual {
        order: -1;
    }
}

@media (max-width: 768px) {
    .navbar {
        padding: 1rem;
    }
    
    .nav-links {
        display: none;
    }
    
    .hero {
        padding: 8rem 1.5rem 4rem;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-desc {
        font-size: 1rem;
    }
    
    .features {
        padding: 4rem 1.5rem;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .security {
        padding: 4rem 1.5rem;
    }
    
    .security-features {
        grid-template-columns: 1fr;
    }
    
    .download {
        padding: 4rem 1.5rem;
    }
    
    .download-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .about {
        padding: 4rem 1.5rem;
    }
    
    .about-stats {
        flex-direction: column;
        gap: 2rem;
    }
    
    .footer {
        padding: 3rem 1.5rem 1.5rem;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    
    .footer-links {
        flex-wrap: wrap;
        gap: 2rem;
    }
    
    .footer-social {
        justify-content: center;
    }
}