/* MChat Website Styles */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&display=swap');

:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --primary-light: #3b82f6;
    --secondary: #0f172a;
    --accent: #06b6d4;
    --success: #10b981;
    --warning: #f59e0b;
    --danger: #ef4444;
    --text: #334155;
    --text-light: #64748b;
    --text-dark: #0f172a;
    --bg: #ffffff;
    --bg-alt: #f8fafc;
    --bg-dark: #0f172a;
    --gradient: linear-gradient(135deg, #2563eb 0%, #06b6d4 100%);
    --gradient-dark: linear-gradient(135deg, #1e3a8a 0%, #0f172a 100%);
    --shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 10px 40px rgba(0, 0, 0, 0.12);
    --radius: 12px;
    --radius-lg: 20px;
    --transition: all 0.3s ease;
}

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

html {
    scroll-behavior: smooth;
}

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

.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);
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.05);
}

.nav-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 70px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 8px;
    text-decoration: none;
    font-weight: 800;
    font-size: 24px;
    color: var(--secondary);
}

.logo-icon {
    font-size: 28px;
}

.logo-text {
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: 32px;
    list-style: none;
}

.nav-menu a {
    text-decoration: none;
    color: var(--text);
    font-weight: 500;
    font-size: 15px;
    transition: var(--transition);
    position: relative;
}

.nav-menu a:hover,
.nav-menu a.active {
    color: var(--primary);
}

.nav-menu a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--gradient);
    transition: var(--transition);
}

.nav-menu a:hover::after,
.nav-menu a.active::after {
    width: 100%;
}

.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    font-size: 24px;
    cursor: pointer;
}

/* 按钮 */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 24px;
    border-radius: var(--radius);
    font-weight: 600;
    font-size: 15px;
    text-decoration: none;
    transition: var(--transition);
    cursor: pointer;
    border: none;
}

.btn-primary {
    background: var(--gradient);
    color: white;
    box-shadow: 0 4px 15px rgba(37, 99, 235, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(37, 99, 235, 0.4);
}

.btn-secondary {
    background: white;
    color: var(--primary);
    border: 2px solid var(--primary);
}

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

.btn-outline {
    background: transparent;
    color: white;
    border: 2px solid rgba(255, 255, 255, 0.3);
}

.btn-outline:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: white;
}

.btn-lg {
    padding: 16px 32px;
    font-size: 16px;
}

/* Hero 区域 */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding: 120px 0 80px;
    background: var(--bg-dark);
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    inset: 0;
    background: 
        radial-gradient(circle at 20% 50%, rgba(37, 99, 235, 0.3) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(6, 182, 212, 0.2) 0%, transparent 40%),
        radial-gradient(circle at 40% 80%, rgba(16, 185, 129, 0.1) 0%, transparent 30%);
}

.hero-content {
    position: relative;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.hero-badge {
    display: inline-block;
    padding: 8px 16px;
    background: rgba(6, 182, 212, 0.2);
    border: 1px solid rgba(6, 182, 212, 0.3);
    border-radius: 20px;
    color: var(--accent);
    font-size: 14px;
    font-weight: 600;
    margin-bottom: 20px;
}

.hero-text h1 {
    font-size: 56px;
    font-weight: 800;
    color: white;
    line-height: 1.1;
    margin-bottom: 24px;
}

.hero-desc {
    font-size: 18px;
    color: rgba(255, 255, 255, 0.7);
    margin-bottom: 32px;
    max-width: 500px;
}

.hero-btns {
    display: flex;
    gap: 16px;
    margin-bottom: 48px;
}

.hero-stats {
    display: flex;
    gap: 40px;
}

.stat {
    text-align: center;
}

.stat-number {
    display: block;
    font-size: 32px;
    font-weight: 800;
    color: white;
}

.stat-label {
    font-size: 14px;
    color: rgba(255, 255, 255, 0.6);
}

/* 手机模拟 */
.hero-visual {
    position: relative;
    display: flex;
    justify-content: center;
    align-items: center;
}

.phone-mockup {
    width: 280px;
    height: 560px;
    background: #1a1a2e;
    border-radius: 40px;
    padding: 12px;
    box-shadow: 
        0 0 0 4px #333,
        0 20px 60px rgba(0, 0, 0, 0.5);
    position: relative;
}

.phone-mockup::before {
    content: '';
    position: absolute;
    top: 20px;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 24px;
    background: #000;
    border-radius: 12px;
}

.phone-screen {
    width: 100%;
    height: 100%;
    background: linear-gradient(180deg, #667eea 0%, #764ba2 100%);
    border-radius: 30px;
    padding: 60px 20px 20px;
    overflow: hidden;
}

.chat-preview {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.chat-bubble {
    max-width: 85%;
    padding: 12px 16px;
    border-radius: 18px;
    font-size: 14px;
    animation: slideIn 0.5s ease;
}

.chat-bubble.sent {
    align-self: flex-end;
    background: #4f46e5;
    color: white;
    border-bottom-right-radius: 4px;
}

.chat-bubble.received {
    align-self: flex-start;
    background: rgba(255, 255, 255, 0.95);
    color: #333;
    border-bottom-left-radius: 4px;
}

.chat-bubble.encrypted {
    align-self: center;
    background: rgba(0, 0, 0, 0.3);
    color: rgba(255, 255, 255, 0.8);
    font-size: 12px;
    text-align: center;
}

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

.floating-elements {
    position: absolute;
    width: 100%;
    height: 100%;
    pointer-events: none;
}

.float-item {
    position: absolute;
    font-size: 32px;
    animation: float 3s ease-in-out infinite;
}

.float-item:nth-child(1) { top: 10%; left: 10%; animation-delay: 0s; }
.float-item:nth-child(2) { top: 20%; right: 10%; animation-delay: 0.5s; }
.float-item:nth-child(3) { bottom: 30%; left: 5%; animation-delay: 1s; }
.float-item:nth-child(4) { bottom: 20%; right: 5%; animation-delay: 1.5s; }

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-20px); }
}

/* 区域标题 */
.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-tag {
    display: inline-block;
    padding: 6px 14px;
    background: rgba(37, 99, 235, 0.1);
    color: var(--primary);
    font-size: 13px;
    font-weight: 600;
    border-radius: 20px;
    margin-bottom: 16px;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.section-header h2 {
    font-size: 40px;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 12px;
}

.section-header p {
    font-size: 18px;
    color: var(--text-light);
}

/* 功能卡片 */
.features-preview {
    padding: 100px 0;
    background: var(--bg);
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.feature-card {
    background: white;
    border-radius: var(--radius-lg);
    padding: 40px 30px;
    box-shadow: var(--shadow);
    transition: var(--transition);
    border: 1px solid rgba(0, 0, 0, 0.05);
}

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

.feature-icon {
    font-size: 48px;
    margin-bottom: 20px;
}

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

.feature-card p {
    color: var(--text-light);
    font-size: 15px;
}

/* 安全区域 */
.security-section {
    padding: 100px 0;
    background: var(--bg-alt);
}

.security-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.security-text h2 {
    font-size: 40px;
    font-weight: 700;
    margin-bottom: 20px;
    color: var(--text-dark);
}

.security-text > p {
    font-size: 17px;
    color: var(--text-light);
    margin-bottom: 30px;
}

.security-list {
    list-style: none;
    margin-bottom: 30px;
}

.security-list li {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 0;
    font-size: 16px;
    color: var(--text-dark);
}

.security-list li span {
    color: var(--success);
    font-weight: bold;
}

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

.shield-animation {
    position: relative;
    width: 200px;
    height: 200px;
}

.shield {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-size: 80px;
    z-index: 10;
}

.shield-ring {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    border: 2px solid var(--primary);
    border-radius: 50%;
    opacity: 0;
    animation: pulse 2s ease-out infinite;
}

.ring1 { width: 100px; height: 100px; animation-delay: 0s; }
.ring2 { width: 150px; height: 150px; animation-delay: 0.5s; }
.ring3 { width: 200px; height: 200px; animation-delay: 1s; }

@keyframes pulse {
    0% { opacity: 0.8; transform: translate(-50%, -50%) scale(0.8); }
    100% { opacity: 0; transform: translate(-50%, -50%) scale(1.2); }
}

/* 下载区域 */
.download-section {
    padding: 100px 0;
    background: var(--gradient);
}

.download-content {
    text-align: center;
    color: white;
}

.download-content h2 {
    font-size: 40px;
    font-weight: 700;
    margin-bottom: 16px;
}

.download-content p {
    font-size: 18px;
    opacity: 0.9;
    margin-bottom: 40px;
}

.platform-icons {
    display: flex;
    justify-content: center;
    gap: 30px;
    margin-bottom: 40px;
}

.platform {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    padding: 20px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: var(--radius);
    transition: var(--transition);
}

.platform:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: translateY(-4px);
}

.platform-icon {
    font-size: 36px;
}

.platform span:last-child {
    color: white;
    font-weight: 500;
}

/* 页脚 */
.footer {
    background: var(--secondary);
    color: white;
    padding: 80px 0 30px;
}

.footer-grid {
    display: grid;
    grid-template-columns: 1.5fr repeat(4, 1fr);
    gap: 40px;
    margin-bottom: 60px;
}

.footer-brand .logo {
    margin-bottom: 16px;
}

.footer-brand p {
    color: rgba(255, 255, 255, 0.6);
    font-size: 14px;
    margin-bottom: 20px;
}

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

.social-links a {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 10px;
    font-size: 18px;
    transition: var(--transition);
}

.social-links a:hover {
    background: var(--primary);
    transform: translateY(-2px);
}

.footer-col h4 {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 20px;
    color: white;
}

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

.footer-col ul li {
    margin-bottom: 12px;
}

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

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

.footer-bottom {
    padding-top: 30px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.footer-bottom p {
    color: rgba(255, 255, 255, 0.5);
    font-size: 14px;
}

.footer-links a {
    color: rgba(255, 255, 255, 0.5);
    text-decoration: none;
    font-size: 14px;
    transition: var(--transition);
}

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

/* 响应式 */
@media (max-width: 1024px) {
    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .hero-text h1 {
        font-size: 42px;
    }

    .hero-desc {
        margin: 0 auto 32px;
    }

    .hero-btns {
        justify-content: center;
    }

    .hero-stats {
        justify-content: center;
    }

    .feature-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .security-content {
        grid-template-columns: 1fr;
    }

    .footer-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .nav-menu {
        display: none;
    }

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

    .hero {
        padding: 100px 0 60px;
    }

    .hero-text h1 {
        font-size: 32px;
    }

    .hero-btns {
        flex-direction: column;
    }

    .hero-stats {
        flex-direction: column;
        gap: 20px;
    }

    .feature-grid {
        grid-template-columns: 1fr;
    }

    .section-header h2 {
        font-size: 28px;
    }

    .platform-icons {
        flex-wrap: wrap;
    }

    .footer-grid {
        grid-template-columns: 1fr;
    }

    .footer-bottom {
        flex-direction: column;
        gap: 16px;
        text-align: center;
    }
}