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

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

.app-container {
    max-width: 1200px;
    margin: 0 auto;
    background: white;
    min-height: 100vh;
    box-shadow: 0 0 20px rgba(0,0,0,0.1);
}

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

.logo {
    font-size: 1.5rem;
    font-weight: bold;
    color: #3498db;
}

.nav-items {
    display: flex;
    gap: 1rem;
}

.nav-btn {
    background: transparent;
    border: 2px solid transparent;
    color: #bdc3c7;
    padding: 0.5rem 1rem;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.nav-btn:hover {
    color: white;
    border-color: #3498db;
}

.nav-btn.active {
    color: white;
    background: #3498db;
    border-color: #3498db;
}

/* Pages */
.page {
    display: none;
    padding: 2rem;
    min-height: calc(100vh - 80px);
}

.page.active {
    display: block;
}

.page-header {
    margin-bottom: 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.page-header h1 {
    color: #2c3e50;
    font-size: 2rem;
}

/* Buttons */
button {
    font-family: inherit;
    font-size: 1rem;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    background: #3498db;
    color: white;
}

button:hover {
    background: #2980b9;
    transform: translateY(-2px);
}

button:active {
    transform: translateY(0);
}

/* Cards */
.card {
    background: white;
    border-radius: 12px;
    padding: 1.5rem;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    margin-bottom: 1rem;
    transition: all 0.3s ease;
}

.card:hover {
    box-shadow: 0 8px 15px rgba(0,0,0,0.15);
    transform: translateY(-2px);
}

/* Progress Bar */
.progress-bar {
    width: 100%;
    height: 20px;
    background: #ecf0f1;
    border-radius: 10px;
    overflow: hidden;
    margin: 1rem 0;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, #3498db, #2ecc71);
    border-radius: 10px;
    transition: width 0.3s ease;
}

/* Filter Options */
.filter-options {
    display: flex;
    gap: 0.5rem;
}

.filter-btn {
    background: #ecf0f1;
    color: #7f8c8d;
    border: none;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.9rem;
}

.filter-btn.active {
    background: #3498db;
    color: white;
}

/* Responsive */
@media (max-width: 768px) {
    .main-nav {
        flex-direction: column;
        gap: 1rem;
        padding: 1rem;
    }
    
    .nav-items {
        flex-wrap: wrap;
        justify-content: center;
    }
    
    .page {
        padding: 1rem;
    }
    
    .page-header {
        flex-direction: column;
        gap: 1rem;
        align-items: flex-start;
    }
}