* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: #f5f7fa;
    color: #333;
    line-height: 1.6;
}
.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
    background: linear-gradient(135deg, #1a73e8, #0d47a1);
    color: white;
    position: sticky;
    top: 0;
    z-index: 1000;
}
.logo {
    font-size: 1.5rem;
    font-weight: bold;
}
.nav-links {
    list-style: none;
    display: flex;
    gap: 1.5rem;
}
.nav-links a {
    color: white;
    text-decoration: none;
    font-weight: 500;
}
.hamburger {
    display: none;
    font-size: 2rem;
    cursor: pointer;
}
.hero {
    text-align: center;
    padding: 4rem 2rem;
    background: linear-gradient(135deg, #e3f2fd, #bbdefb);
}
.hero h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}
.hero p {
    font-size: 1.2rem;
    margin-bottom: 2rem;
    color: #555;
}
.btn-primary, .btn-secondary, .btn-link {
    display: inline-block;
    padding: 0.8rem 2rem;
    background: #1a73e8;
    color: white;
    text-decoration: none;
    border-radius: 50px;
    font-weight: bold;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(26,115,232,0.3);
}
.btn-primary:hover, .btn-secondary:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(26,115,232,0.5);
}
.btn-secondary {
    background: #0d47a1;
}
.btn-link {
    background: transparent;
    color: #1a73e8;
    box-shadow: none;
    padding: 0.5rem 1rem;
}
.compatibility-badges {
    margin-top: 1.5rem;
    display: flex;
    justify-content: center;
    gap: 1rem;
    flex-wrap: wrap;
}
.compatibility-badges span {
    background: white;
    padding: 0.3rem 1rem;
    border-radius: 20px;
    font-weight: 500;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}
section {
    padding: 3rem 2rem;
    max-width: 1200px;
    margin: auto;
}
section h2 {
    text-align: center;
    margin-bottom: 2rem;
    font-size: 2rem;
    color: #0d47a1;
}
.feature-grid, .testimonial-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}
.feature-card, .testimonial-card, .version-item {
    background: white;
    border-radius: 16px;
    padding: 2rem;
    box-shadow: 0 8px 30px rgba(0,0,0,0.08);
    transition: transform 0.3s, box-shadow 0.3s;
}
.feature-card:hover, .testimonial-card:hover, .version-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 40px rgba(0,0,0,0.15);
}
.feature-card .icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}
.version-list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
}
.stars {
    color: #ffc107;
    font-size: 1.2rem;
    margin-bottom: 0.5rem;
}
details {
    background: white;
    border-radius: 12px;
    padding: 1rem 1.5rem;
    margin-bottom: 1rem;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    cursor: pointer;
}
details summary {
    font-weight: bold;
    font-size: 1.1rem;
}
details p {
    margin-top: 0.8rem;
    color: #555;
}
.timeline {
    position: relative;
    padding-left: 2rem;
    border-left: 3px solid #1a73e8;
}
.timeline-item {
    margin-bottom: 2rem;
}
.timeline-item h3 {
    color: #0d47a1;
}
.timeline-item ul {
    margin-left: 1.5rem;
    list-style: disc;
}
.qrcode-section {
    text-align: center;
}
.qrcode-container {
    display: inline-block;
    background: white;
    padding: 2rem;
    border-radius: 16px;
    box-shadow: 0 8px 30px rgba(0,0,0,0.1);
}
.qrcode-placeholder {
    width: 200px;
    height: 200px;
    background: #e0e0e0;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: auto;
    border-radius: 12px;
    font-size: 1rem;
    color: #666;
}
footer {
    text-align: center;
    padding: 2rem;
    background: #0d47a1;
    color: white;
}
footer a {
    color: #bbdefb;
    text-decoration: none;
}
.admin-body {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background: #e3f2fd;
}
.login-form, .admin-panel {
    background: white;
    padding: 2rem;
    border-radius: 16px;
    box-shadow: 0 8px 30px rgba(0,0,0,0.1);
    width: 100%;
    max-width: 400px;
}
.admin-panel {
    max-width: 600px;
}
.login-form h1, .admin-panel h1 {
    text-align: center;
    margin-bottom: 1.5rem;
}
.login-form input, .admin-panel input {
    width: 100%;
    padding: 0.8rem;
    margin-bottom: 1rem;
    border: 1px solid #ddd;
    border-radius: 8px;
}
.login-form button, .admin-panel button {
    width: 100%;
    padding: 0.8rem;
    background: #1a73e8;
    color: white;
    border: none;
    border-radius: 8px;
    font-weight: bold;
    cursor: pointer;
}
.login-form a, .admin-panel a {
    display: block;
    text-align: center;
    margin-top: 1rem;
    color: #1a73e8;
    text-decoration: none;
}
.error {
    color: red;
    text-align: center;
}
.success {
    color: green;
    text-align: center;
}
.btn-logout {
    display: inline-block;
    margin-bottom: 1rem;
    padding: 0.5rem 1rem;
    background: #e53935;
    color: white;
    text-decoration: none;
    border-radius: 8px;
}
@media (max-width: 768px) {
    .nav-links {
        display: none;
        flex-direction: column;
        background: #0d47a1;
        position: absolute;
        top: 60px;
        right: 0;
        width: 200px;
        padding: 1rem;
        border-radius: 0 0 12px 12px;
    }
    .nav-links.active {
        display: flex;
    }
    .hamburger {
        display: block;
    }
    .hero h1 {
        font-size: 1.8rem;
    }
}