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

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

.header {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    padding: 1rem 0;
    box-shadow: 0 2px 20px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 50;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.5rem;
    font-weight: 700;
    color: #4285f4;
}

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

.nav a {
    text-decoration: none;
    color: #666;
    font-weight: 500;
    transition: color 0.3s;
}

.nav a:hover, .nav a.active {
    color: #4285f4;
}

.main {
    padding: 3rem 0;
}

.hero {
    text-align: center;
    color: white;
    margin-bottom: 4rem;
}

.hero h1 {
    font-size: 3rem;
    margin-bottom: 1rem;
    font-weight: 700;
}

.hero p {
    font-size: 1.2rem;
    opacity: 0.9;
    max-width: 600px;
    margin: 0 auto 2rem;
}

.btn {
    background: #4285f4;
    color: white;
    border: none;
    padding: 15px 30px;
    border-radius: 10px;
    font-size: 1.1rem;
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: 600;
    text-decoration: none;
    display: inline-block;
}

.btn:hover {
    background: #3367d6;
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(66, 133, 244, 0.3);
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.stat-card {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    padding: 2rem;
    border-radius: 15px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
    text-align: center;
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.stat-icon {
    width: 60px;
    height: 60px;
    background: #4285f4;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1rem;
    font-size: 1.5rem;
}

.stat-number {
    font-size: 2.5rem;
    font-weight: 700;
    color: #4285f4;
    margin-bottom: 0.5rem;
}

.stat-label {
    color: #666;
    font-size: 0.9rem;
}

.features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.feature-card {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    padding: 2rem;
    border-radius: 15px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

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

.feature-card h3 {
    font-size: 1.3rem;
    margin-bottom: 1rem;
    color: #333;
}

.feature-card p {
    color: #666;
    line-height: 1.6;
}

.usage-form {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    padding: 2rem;
    border-radius: 15px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
    max-width: 500px;
    margin: 0 auto;
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: #333;
}

.form-group input, 
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 12px;
    border: 2px solid #e1e5e9;
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s;
}

.form-group input:focus, 
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: #4285f4;
}

.hidden {
    display: none !important;
}

.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
}

.modal-content {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    padding: 2rem;
    border-radius: 15px;
    max-width: 400px;
    width: 90%;
    position: relative;
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.close-btn {
    position: absolute;
    top: 10px;
    right: 15px;
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: #666;
}

.auth-toggle {
    display: flex;
    margin-bottom: 1.5rem;
    background: #f0f0f0;
    border-radius: 8px;
    padding: 4px;
}

.auth-toggle button {
    flex: 1;
    padding: 8px 16px;
    border: none;
    background: none;
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.3s;
}

.auth-toggle button.active {
    background: white;
    color: #4285f4;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.notification {
    position: fixed;
    top: 20px;
    right: 20px;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    padding: 1rem 1.5rem;
    border-radius: 10px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    z-index: 1100;
    min-width: 300px;
    animation: slideInRight 0.3s ease;
}

.notification.success { border-left: 4px solid #22c55e; }
.notification.error { border-left: 4px solid #ef4444; }
.notification.warning { border-left: 4px solid #f59e0b; }
.notification.info { border-left: 4px solid #3b82f6; }

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

.user-info {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.user-info span {
    color: #666;
    font-size: 0.9rem;
}

.logout-btn {
    background: none;
    border: none;
    color: #666;
    cursor: pointer;
    font-size: 0.9rem;
    transition: color 0.3s;
}

.logout-btn:hover {
    color: #ef4444;
}

@media (max-width: 768px) {
    .hero h1 {
        font-size: 2rem;
    }
    
    .nav {
        display: none;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
    
    .header-content {
        flex-wrap: wrap;
        gap: 1rem;
    }
}