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

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

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header */
.header {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.2);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
}

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

.logo {
    font-size: 1.8rem;
    font-weight: 700;
    color: white;
    text-decoration: none;
}

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

.nav-link {
    color: white;
    text-decoration: none;
    font-weight: 500;
    transition: opacity 0.3s;
}

.nav-link:hover {
    opacity: 0.8;
}

.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
    padding: 5px;
}

.hamburger span {
    width: 25px;
    height: 3px;
    background: white;
    margin: 3px 0;
    transition: 0.3s;
    border-radius: 2px;
}

/* Hero Section */
.hero {
    text-align: center;
    padding: 4rem 0;
    color: white;
}

.hero h1 {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    background: linear-gradient(45deg, #fff, #f0f0f0);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero p {
    font-size: 1.3rem;
    margin-bottom: 3rem;
    opacity: 0.9;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.cta-buttons {
    display: flex;
    gap: 2rem;
    justify-content: center;
    flex-wrap: wrap;
}

.btn {
    padding: 1rem 2.5rem;
    border: none;
    border-radius: 50px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    transition: all 0.3s ease;
    box-shadow: 0 8px 25px rgba(0,0,0,0.15);
}

.btn-primary {
    background: linear-gradient(45deg, #ff6b6b, #ee5a52);
    color: white;
}

.btn-secondary {
    background: linear-gradient(45deg, #4ecdc4, #44a08d);
    color: white;
}

.btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 12px 35px rgba(0,0,0,0.2);
}

/* Forms */
.form-container {
    background: white;
    border-radius: 20px;
    padding: 2.5rem;
    box-shadow: 0 20px 60px rgba(0,0,0,0.1);
    max-width: 500px;
    margin: 2rem auto;
}

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

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

.form-control {
    width: 100%;
    padding: 0.875rem;
    border: 2px solid #e1e5e9;
    border-radius: 10px;
    font-size: 1rem;
    transition: border-color 0.3s;
}

.form-control:focus {
    outline: none;
    border-color: #667eea;
}

.select-control {
    appearance: none;
    background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 20 20'%3e%3cpath stroke='%236b7280' stroke-linecap='round' stroke-linejoin='round' stroke-width='1.5' d='M6 8l4 4 4-4'/%3e%3c/svg%3e");
    background-position: right 0.5rem center;
    background-repeat: no-repeat;
    background-size: 1.5em 1.5em;
    padding-right: 2.5rem;
}

/* Expense Form */
.expense-form {
    background: white;
    border-radius: 20px;
    padding: 2rem;
    margin: 2rem 0;
    box-shadow: 0 10px 40px rgba(0,0,0,0.1);
}

.category-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.category-item {
    background: #f8f9fa;
    border: 2px solid transparent;
    border-radius: 12px;
    padding: 1rem;
    cursor: pointer;
    transition: all 0.3s;
    text-align: center;
}

.category-item:hover {
    background: #e9ecef;
}

.category-item.active {
    background: linear-gradient(45deg, #667eea, #764ba2);
    color: white;
    border-color: #667eea;
}

.category-emoji {
    font-size: 2rem;
    display: block;
    margin-bottom: 0.5rem;
}

.category-name {
    font-weight: 600;
    font-size: 0.9rem;
}

/* Dashboard */
.dashboard {
    padding: 2rem 0;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.stat-card {
    background: white;
    border-radius: 15px;
    padding: 1.5rem;
    box-shadow: 0 5px 20px rgba(0,0,0,0.08);
    text-align: center;
}

.stat-value {
    font-size: 2rem;
    font-weight: 700;
    color: #333;
    margin-bottom: 0.5rem;
}

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

.chart-container {
    background: white;
    border-radius: 20px;
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: 0 10px 40px rgba(0,0,0,0.1);
}

.expense-list {
    background: white;
    border-radius: 20px;
    padding: 2rem;
    box-shadow: 0 10px 40px rgba(0,0,0,0.1);
}

.expense-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem;
    border-bottom: 1px solid #eee;
}

.expense-item:last-child {
    border-bottom: none;
}

.expense-info h4 {
    margin: 0 0 0.25rem 0;
    font-weight: 600;
}

.expense-meta {
    font-size: 0.85rem;
    color: #666;
}

.expense-amount {
    font-weight: 700;
    font-size: 1.1rem;
    color: #333;
}

/* Responsive */
@media (max-width: 768px) {
    .hamburger {
        display: flex;
    }
    
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background: rgba(255, 255, 255, 0.95);
        backdrop-filter: blur(10px);
        width: 100%;
        text-align: center;
        transition: 0.3s;
        padding: 2rem 0;
    }
    
    .nav-menu.active {
        left: 0;
    }
    
    .nav-link {
        color: #333;
    }
    
    .hero h1 {
        font-size: 2.5rem;
    }
    
    .cta-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .category-grid {
        grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
}

/* Login/Register Forms */
.auth-container {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 2rem;
}

.auth-form {
    width: 100%;
    max-width: 400px;
}

.auth-form h2 {
    text-align: center;
    color: white;
    margin-bottom: 2rem;
    font-size: 2rem;
}

.auth-links {
    text-align: center;
    margin-top: 1.5rem;
}

.auth-links a {
    color: #667eea;
    text-decoration: none;
}

.auth-links a:hover {
    text-decoration: underline;
}

/* Alerts */
.alert {
    padding: 1rem;
    border-radius: 8px;
    margin-bottom: 1rem;
}

.alert-success {
    background: #d1edff;
    color: #0c63e4;
    border: 1px solid #b7e1ff;
}

.alert-error {
    background: #ffeaa7;
    color: #e17055;
    border: 1px solid #fdcb6e;
}