* {
    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 {
    background: #2c3e50;
    color: white;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-brand {
    font-size: 1.5rem;
    font-weight: bold;
}

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

.nav-menu a {
    color: white;
    text-decoration: none;
    transition: color 0.3s;
}

.nav-menu a:hover,
.nav-menu a.active {
    color: #3498db;
}

.container {
    max-width: 1200px;
    margin: 2rem auto;
    padding: 0 2rem;
}

h1 {
    margin-bottom: 2rem;
    color: #2c3e50;
}

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

.stat-card {
    background: white;
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    text-align: center;
}

.stat-card h3 {
    color: #7f8c8d;
    font-size: 0.9rem;
    margin-bottom: 1rem;
    text-transform: uppercase;
}

.stat-number {
    font-size: 2.5rem;
    font-weight: bold;
    color: #27ae60;
    margin-bottom: 0.5rem;
}

.stat-label {
    color: #95a5a6;
    font-size: 0.9rem;
}

.recent-activities {
    background: white;
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.activity-list {
    margin-top: 1rem;
}

.activity-item {
    display: flex;
    justify-content: space-between;
    padding: 1rem 0;
    border-bottom: 1px solid #ecf0f1;
}

.activity-time {
    color: #7f8c8d;
    font-size: 0.9rem;
}

.profile-form {
    background: white;
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    max-width: 500px;
}

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

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
}

.form-group input,
.form-group select {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid #ddd;
    border-radius: 5px;
    font-size: 1rem;
}

button {
    background: #3498db;
    color: white;
    padding: 0.75rem 2rem;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-size: 1rem;
    transition: background 0.3s;
}

button:hover {
    background: #2980b9;
}

.text-center {
    text-align: center;
}

@media (max-width: 768px) {
    .navbar {
        flex-direction: column;
        gap: 1rem;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
    
    .activity-item {
        flex-direction: column;
        gap: 0.5rem;
    }
}