/* MChat 官网全局样式 */
:root {
    --primary-dark: #0A1628;
    --bg-dark: #0F172A;
    --bg-card: #1E293B;
    --tech-blue: #2563EB;
    --tech-blue-light: #3B82F6;
    --accent-cyan: #06B6D4;
    --security-green: #10B981;
    --text-white: #FFFFFF;
    --text-light: #E2E8F0;
    --text-muted: #94A3B8;
    --border-color: #334155;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
    background-color: var(--bg-dark);
    color: var(--text-light);
    line-height: 1.6;
    font-size: 16px;
}

a {
    color: var(--tech-blue-light);
    text-decoration: none;
    transition: color 0.3s;
}

a:hover {
    color: var(--accent-cyan);
}

/* Header */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(10, 22, 40, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    padding: 0 2rem;
    height: 70px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.header-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--text-white);
}

.header-logo .logo-icon {
    width: 36px;
    height: 36px;
    background: linear-gradient(135deg, var(--tech-blue), var(--accent-cyan));
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
}

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

.header-nav a {
    color: var(--text-light);
    font-size: 0.95rem;
    padding: 0.5rem 0;
    position: relative;
}

.header-nav a:hover {
    color: var(--accent-cyan);
}

.header-nav a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent-cyan);
    transition: width 0.3s;
}

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

.btn-primary {
    display: inline-block;
    background: linear-gradient(135deg, var(--tech-blue), var(--tech-blue-light));
    color: var(--text-white);
    padding: 0.6rem 1.5rem;
    border-radius: 8px;
    font-weight: 600;
    font-size: 0.95rem;
    transition: transform 0.3s, box-shadow 0.3s;
    border: none;
    cursor: pointer;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(37, 99, 235, 0.4);
    color: var(--text-white);
}

.btn-secondary {
    display: inline-block;
    background: transparent;
    color: var(--text-white);
    padding: 0.6rem 1.5rem;
    border-radius: 8px;
    font-weight: 600;
    font-size: 0.95rem;
    border: 2px solid var(--border-color);
    transition: border-color 0.3s, background 0.3s;
}

.btn-secondary:hover {
    border-color: var(--accent-cyan);
    background: rgba(6, 182, 212, 0.1);
    color: var(--accent-cyan);
}

/* Mobile menu */
.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    color: var(--text-white);
    font-size: 1.5rem;
    cursor: pointer;
}

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 120px 2rem 80px;
    background: radial-gradient(ellipse at center, rgba(37, 99, 235, 0.15) 0%, transparent 70%);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle at 30% 50%, rgba(6, 182, 212, 0.05) 0%, transparent 50%),
                radial-gradient(circle at 70% 50%, rgba(37, 99, 235, 0.05) 0%, transparent 50%);
    animation: float 20s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translate(0, 0); }
    50% { transform: translate(-2%, 2%); }
}

.hero-content {
    position: relative;
    z-index: 1;
    max-width: 800px;
}

.hero h1 {
    font-size: 3.5rem;
    font-weight: 800;
    color: var(--text-white);
    margin-bottom: 1.5rem;
    line-height: 1.2;
}

.hero h1 .highlight {
    background: linear-gradient(135deg, var(--accent-cyan), var(--tech-blue-light));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero p {
    font-size: 1.2rem;
    color: var(--text-muted);
    margin-bottom: 2.5rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

.hero-visual {
    margin-top: 4rem;
    position: relative;
}

.lock-animation {
    width: 120px;
    height: 120px;
    margin: 0 auto;
    background: linear-gradient(135deg, var(--tech-blue), var(--accent-cyan));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 3rem;
    box-shadow: 0 0 60px rgba(6, 182, 212, 0.3);
    animation: pulse 3s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% { box-shadow: 0 0 60px rgba(6, 182, 212, 0.3); }
    50% { box-shadow: 0 0 80px rgba(6, 182, 212, 0.5); }
}

/* Section Common */
.section {
    padding: 100px 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--text-white);
    margin-bottom: 1rem;
}

.section-subtitle {
    text-align: center;
    font-size: 1.1rem;
    color: var(--text-muted);
    margin-bottom: 4rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

/* Trust Badges */
.trust-badges {
    background: var(--primary-dark);
    padding: 60px 2rem;
}

.trust-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

.trust-item {
    text-align: center;
    padding: 2rem 1rem;
}

.trust-icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.trust-item h3 {
    font-size: 1.1rem;
    color: var(--text-white);
    margin-bottom: 0.5rem;
}

.trust-item p {
    font-size: 0.9rem;
    color: var(--text-muted);
}

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

.feature-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 2rem;
    transition: transform 0.3s, box-shadow 0.3s, border-color 0.3s;
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
    border-color: var(--accent-cyan);
}

.feature-icon {
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, rgba(37, 99, 235, 0.2), rgba(6, 182, 212, 0.2));
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
}

.feature-card h3 {
    font-size: 1.2rem;
    color: var(--text-white);
    margin-bottom: 0.8rem;
}

.feature-card p {
    font-size: 0.95rem;
    color: var(--text-muted);
    line-height: 1.7;
}

/* Security Section */
.security-section {
    background: var(--primary-dark);
    padding: 100px 2rem;
}

.security-content {
    max-width: 1200px;
    margin: 0 auto;
}

.security-flow {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 2rem;
    margin: 3rem 0;
    flex-wrap: wrap;
}

.flow-step {
    text-align: center;
    padding: 2rem;
    background: var(--bg-card);
    border-radius: 16px;
    border: 1px solid var(--border-color);
    min-width: 200px;
}

.flow-step .step-icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.flow-step h4 {
    color: var(--text-white);
    margin-bottom: 0.5rem;
}

.flow-step p {
    color: var(--text-muted);
    font-size: 0.9rem;
}

.flow-arrow {
    font-size: 2rem;
    color: var(--accent-cyan);
}

.security-promises {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
    margin-top: 4rem;
}

.promise-item {
    text-align: center;
    padding: 2rem;
}

.promise-icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--security-green), var(--accent-cyan));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    margin: 0 auto 1.5rem;
}

.promise-item h3 {
    color: var(--text-white);
    margin-bottom: 0.8rem;
    font-size: 1.2rem;
}

.promise-item p {
    color: var(--text-muted);
    font-size: 0.95rem;
}

/* Platforms */
.platforms-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 2rem;
    max-width: 900px;
    margin: 0 auto;
}

.platform-card {
    text-align: center;
    padding: 2rem;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    transition: transform 0.3s, border-color 0.3s;
}

.platform-card:hover {
    transform: translateY(-3px);
    border-color: var(--tech-blue-light);
}

.platform-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.platform-card h3 {
    color: var(--text-white);
    margin-bottom: 1rem;
    font-size: 1.1rem;
}

/* Social Proof */
.social-proof {
    background: var(--primary-dark);
    padding: 80px 2rem;
    text-align: center;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 3rem;
    max-width: 800px;
    margin: 0 auto;
}

.stat-item h3 {
    font-size: 2.5rem;
    font-weight: 800;
    background: linear-gradient(135deg, var(--accent-cyan), var(--tech-blue-light));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 0.5rem;
}

.stat-item p {
    color: var(--text-muted);
}

/* Footer */
.footer {
    background: var(--primary-dark);
    border-top: 1px solid var(--border-color);
    padding: 60px 2rem 30px;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 3rem;
}

.footer-brand p {
    color: var(--text-muted);
    margin-top: 1rem;
    font-size: 0.9rem;
}

.footer-col h4 {
    color: var(--text-white);
    margin-bottom: 1rem;
    font-size: 1rem;
}

.footer-col a {
    display: block;
    color: var(--text-muted);
    margin-bottom: 0.5rem;
    font-size: 0.9rem;
}

.footer-col a:hover {
    color: var(--accent-cyan);
}

.footer-bottom {
    max-width: 1200px;
    margin: 3rem auto 0;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
}

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

.footer-bottom-links {
    display: flex;
    gap: 1.5rem;
}

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

/* FAQ Page */
.faq-section {
    padding: 120px 2rem 80px;
    max-width: 900px;
    margin: 0 auto;
}

.faq-category {
    margin-bottom: 3rem;
}

.faq-category h2 {
    font-size: 1.5rem;
    color: var(--text-white);
    margin-bottom: 1.5rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid var(--tech-blue);
    display: inline-block;
}

.faq-item {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 1.5rem 2rem;
    margin-bottom: 1rem;
}

.faq-item h3 {
    color: var(--accent-cyan);
    font-size: 1.1rem;
    margin-bottom: 1rem;
}

.faq-item .answer {
    color: var(--text-light);
    line-height: 1.8;
}

.faq-item .answer ol {
    padding-left: 1.5rem;
    margin-top: 0.5rem;
}

.faq-item .answer ol li {
    margin-bottom: 0.5rem;
    color: var(--text-muted);
}

/* About Page */
.about-hero {
    padding: 120px 2rem 60px;
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
}

.about-hero h1 {
    font-size: 2.5rem;
    color: var(--text-white);
    margin-bottom: 1.5rem;
}

.about-hero p {
    font-size: 1.1rem;
    color: var(--text-muted);
    line-height: 1.8;
}

.about-values {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
    max-width: 1000px;
    margin: 4rem auto;
    padding: 0 2rem;
}

.value-card {
    text-align: center;
    padding: 2rem;
    background: var(--bg-card);
    border-radius: 16px;
    border: 1px solid var(--border-color);
}

.value-card .value-icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.value-card h3 {
    color: var(--text-white);
    margin-bottom: 0.8rem;
}

.value-card p {
    color: var(--text-muted);
    font-size: 0.95rem;
}

/* Download Page */
.download-hero {
    padding: 120px 2rem 60px;
    text-align: center;
}

.download-hero h1 {
    font-size: 2.5rem;
    color: var(--text-white);
    margin-bottom: 1rem;
}

.download-hero p {
    color: var(--text-muted);
    font-size: 1.1rem;
}

.download-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 2rem;
    max-width: 800px;
    margin: 3rem auto;
    padding: 0 2rem;
}

.download-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 2.5rem;
    text-align: center;
    transition: transform 0.3s, border-color 0.3s;
}

.download-card:hover {
    transform: translateY(-3px);
    border-color: var(--tech-blue-light);
}

.download-card .platform-icon {
    font-size: 3.5rem;
    margin-bottom: 1rem;
}

.download-card h3 {
    color: var(--text-white);
    margin-bottom: 0.5rem;
    font-size: 1.3rem;
}

.download-card p {
    color: var(--text-muted);
    margin-bottom: 1.5rem;
    font-size: 0.9rem;
}

/* Responsive */
@media (max-width: 1024px) {
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .trust-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .footer-content {
        grid-template-columns: 1fr 1fr;
    }
    .security-promises {
        grid-template-columns: 1fr;
    }
    .platforms-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .header-nav {
        display: none;
    }
    .mobile-menu-btn {
        display: block;
    }
    .hero h1 {
        font-size: 2.2rem;
    }
    .hero p {
        font-size: 1rem;
    }
    .section-title {
        font-size: 1.8rem;
    }
    .features-grid {
        grid-template-columns: 1fr;
    }
    .trust-grid {
        grid-template-columns: 1fr;
    }
    .security-flow {
        flex-direction: column;
    }
    .flow-arrow {
        transform: rotate(90deg);
    }
    .platforms-grid {
        grid-template-columns: 1fr;
    }
    .stats-grid {
        grid-template-columns: 1fr;
    }
    .footer-content {
        grid-template-columns: 1fr;
    }
    .download-grid {
        grid-template-columns: 1fr;
    }
    .about-values {
        grid-template-columns: 1fr;
    }
    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }
}