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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    line-height: 1.6;
    color: #333;
}

.page {
    display: none;
}

.page.active {
    display: block;
}

/* Header & Navigation */
header {
    background: #fff;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 100;
}

nav {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
}

.logo {
    font-size: 1.5rem;
    font-weight: bold;
    color: #1877f2;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-links a {
    text-decoration: none;
    color: #333;
    font-weight: 500;
    transition: color 0.3s;
}

.nav-links a:hover {
    color: #1877f2;
}

/* Main Content */
main {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}

.hero {
    text-align: center;
    padding: 4rem 2rem;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border-radius: 10px;
    margin-bottom: 3rem;
}

.hero h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.hero p {
    font-size: 1.2rem;
    margin-bottom: 2rem;
}

.cta-button {
    background: white;
    color: #667eea;
    border: none;
    padding: 1rem 2rem;
    font-size: 1rem;
    font-weight: bold;
    border-radius: 5px;
    cursor: pointer;
    transition: transform 0.3s, box-shadow 0.3s;
}

.cta-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.2);
}

/* Features Section */
.features {
    margin-bottom: 3rem;
}

.features h2 {
    text-align: center;
    font-size: 2rem;
    margin-bottom: 2rem;
    color: #333;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.feature-card {
    background: #f8f9fa;
    padding: 2rem;
    border-radius: 10px;
    text-align: center;
    transition: transform 0.3s, box-shadow 0.3s;
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0,0,0,0.1);
}

.feature-card h3 {
    color: #1877f2;
    margin-bottom: 1rem;
}

/* About Section */
.about {
    background: #f8f9fa;
    padding: 3rem;
    border-radius: 10px;
    margin-bottom: 3rem;
}

.about h2 {
    font-size: 2rem;
    margin-bottom: 1rem;
    color: #333;
}

.about p {
    font-size: 1.1rem;
    margin-bottom: 1rem;
    color: #666;
}

/* Contact Section */
.contact {
    margin-bottom: 3rem;
}

.contact h2 {
    text-align: center;
    font-size: 2rem;
    margin-bottom: 2rem;
    color: #333;
}

.contact-form {
    max-width: 600px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.contact-form input,
.contact-form textarea {
    padding: 1rem;
    border: 1px solid #ddd;
    border-radius: 5px;
    font-size: 1rem;
    font-family: inherit;
}

.contact-form button {
    background: #1877f2;
    color: white;
    border: none;
    padding: 1rem;
    font-size: 1rem;
    font-weight: bold;
    border-radius: 5px;
    cursor: pointer;
    transition: background 0.3s;
}

.contact-form button:hover {
    background: #166fe5;
}

/* Footer */
footer {
    background: #333;
    color: white;
    text-align: center;
    padding: 2rem;
}

footer a {
    color: #1877f2;
    text-decoration: none;
}

footer a:hover {
    text-decoration: underline;
}

/* Loading Page */
#loadingPage {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    height: 100vh;
    background: #f8f9fa;
}

.loading-spinner {
    border: 4px solid #f3f3f3;
    border-top: 4px solid #1877f2;
    border-radius: 50%;
    width: 50px;
    height: 50px;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-links {
        gap: 1rem;
    }
    
    .hero h1 {
        font-size: 2rem;
    }
    
    .feature-grid {
        grid-template-columns: 1fr;
    }
}