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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: #333;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 2rem;
    text-align: center;
}

.main-card {
    background: rgba(255, 255, 255, 0.95);
    border-radius: 20px;
    padding: 3rem 2rem;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
    backdrop-filter: blur(10px);
}

.title {
    font-size: 1.5rem;
    color: #333;
    margin-bottom: 1rem;
}

.video-container {
    margin: 2rem 0;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
}

.video-tabs {
    display: flex;
    background: #f5f5f5;
    border-bottom: 2px solid #e0e0e0;
}

.video-tab {
    flex: 1;
    padding: 12px 20px;
    background: transparent;
    border: none;
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    color: #666;
    transition: all 0.3s ease;
    position: relative;
}

.video-tab:hover {
    background: #e8e8e8;
    color: #333;
}

.video-tab.active {
    color: #667eea;
    background: white;
}

.video-tab.active::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    right: 0;
    height: 2px;
    background: #667eea;
}

.demo-video {
    width: 100%;
    height: auto;
    display: none !important;
}

.demo-video.active {
    display: block !important;
}

.demo-video.is-failed {
    display: none !important;
}

.download-area {
    margin-top: 1.5rem;
}

.download-area .buttons {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
    margin-top: 1rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.btn {
    min-width: 180px;
    padding: 12px 24px;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    text-decoration: none;
    cursor: pointer;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

.btn-primary {
    background: linear-gradient(135deg, #667eea, #764ba2);
    color: white;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(102, 126, 234, 0.3);
}

.btn-secondary {
    background: #f8f9fa;
    color: #333;
    border: 2px solid #e9ecef;
}

.btn-secondary:hover {
    background: #e9ecef;
    transform: translateY(-2px);
}

.btn-outline {
    background: rgba(255, 255, 255, 0.2);
    border: 2px solid white;
    color: white;
}

.btn-outline:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: translateY(-2px);
}

.android-download {
    position: relative;
    background: linear-gradient(135deg, #4ade80, #22c55e) !important;
    display: inline-flex;
    align-items: center;
    gap: 0.75rem;
    padding: 1rem 1.5rem !important;
    cursor: pointer;
    transition: all 0.3s ease;
    border-radius: 8px;
    border: none;
    color: white;
    user-select: none;
}

.android-download:hover {
    background: linear-gradient(135deg, #22c55e, #16a34a) !important;
    transform: translateY(-2px);
}

.free-notice {
    text-align: center;
    color: #0ea5e9;
    font-weight: 600;
    margin: 1rem 0;
}

.security-warning {
    margin: 1rem auto;
    padding: 0.85rem 1rem;
    background: #fff8e1;
    color: #b45309;
    border: 1px solid #fbbf24;
    border-radius: 12px;
    font-size: 0.95rem;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    width: 80%;
    max-width: 80%;
    line-height: 1.5;
}

.video-fallback {
    display: none;
}

.video-fallback-card {
    background: linear-gradient(135deg, #667eea, #764ba2);
    color: white;
    padding: 4rem 2rem;
    border-radius: 12px;
    text-align: center;
}

.video-fallback-icon {
    font-size: 4rem;
    margin-bottom: 1rem;
    opacity: 0.7;
}

.video-fallback-link {
    border-radius: 8px;
}

.contact-section-beautiful {
    margin-top: 2rem;
    padding-top: 2rem;
    border-top: 1px solid #e9ecef;
}

.contact-subtitle {
    color: #6b7280;
    margin-top: 0.25rem;
}

.contact-cards {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
    margin-top: 1.25rem;
}

.contact-card {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem 1.25rem;
    border-radius: 12px;
    background: #f8fafc;
    border: 1px solid #e5e7eb;
    color: #111827;
    text-decoration: none;
    transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
}

.contact-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.08);
    background: #ffffff;
}

.contact-card-icon {
    width: 44px;
    height: 44px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    flex: 0 0 auto;
}

.telegram-card .contact-card-icon {
    background: linear-gradient(135deg, #2aabee, #229ed9);
}

.wechat-card .contact-card-icon {
    background: linear-gradient(135deg, #22c55e, #16a34a);
}

.contact-card-info {
    text-align: left;
    flex: 1 1 auto;
    min-width: 0;
}

.contact-card-info h3 {
    font-size: 1rem;
    margin: 0;
}

.contact-card-info p {
    margin: 0.15rem 0 0;
    color: #6b7280;
    font-size: 0.95rem;
}

.contact-card-qr {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.35rem;
    flex: 0 0 auto;
}

.contact-card-qr img {
    width: 58px;
    height: 58px;
    border-radius: 10px;
    object-fit: cover;
    border: 1px solid #e5e7eb;
}

.qr-hint {
    font-size: 0.8rem;
    color: #6b7280;
}

.footer {
    margin-top: 2rem;
    font-size: 0.9rem;
    color: #999;
}

@keyframes slideIn {
    from {
        transform: translateX(100%);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}

@keyframes slideOut {
    from {
        transform: translateX(0);
        opacity: 1;
    }
    to {
        transform: translateX(100%);
        opacity: 0;
    }
}

@media (max-width: 768px) {
    .container {
        padding: 1rem;
    }

    .main-card {
        padding: 2rem 1.5rem;
    }

    .title {
        font-size: 1.3rem;
    }

    .download-area .buttons {
        grid-template-columns: 1fr;
    }

    .btn {
        width: 100%;
        max-width: 300px;
        justify-content: center;
    }

    .security-warning {
        width: 100%;
        max-width: 100%;
    }

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