:root {
    --primary-color: #03a9f4;
    --secondary-color: #4caf50;
    --background-color: #f5f5f5;
    --card-background: #ffffff;
    --text-color: #212121;
    --text-secondary: #757575;
    --border-color: #e0e0e0;
    --sidebar-width: 250px;
    --header-height: 60px;
    --shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

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

body {
    font-family: 'Roboto', 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--background-color);
    color: var(--text-color);
    line-height: 1.6;
}

/* Sidebar */
.sidebar {
    position: fixed;
    width: var(--sidebar-width);
    height: 100vh;
    background-color: var(--card-background);
    box-shadow: var(--shadow);
    z-index: 100;
    overflow-y: auto;
}

.sidebar-header {
    padding: 20px;
    display: flex;
    align-items: center;
    border-bottom: 1px solid var(--border-color);
}

.sidebar-header i {
    font-size: 24px;
    color: var(--primary-color);
    margin-right: 10px;
}

.sidebar-header h2 {
    font-size: 18px;
    font-weight: 500;
}

.sidebar nav ul {
    list-style: none;
}

.sidebar nav ul li a {
    display: flex;
    align-items: center;
    padding: 15px 20px;
    color: var(--text-color);
    text-decoration: none;
    transition: background-color 0.3s;
}

.sidebar nav ul li a:hover {
    background-color: rgba(0, 0, 0, 0.05);
}

.sidebar nav ul li a i {
    margin-right: 10px;
    color: var(--primary-color);
}

/* Main Content */
.main-content {
    margin-left: var(--sidebar-width);
    padding: 20px;
}

.content-wrapper {
    max-width: 1200px;
    margin: 0 auto;
}

/* Dashboard */
.dashboard h1, .expenses-page h1, .categories-page h1, .reports-page h1 {
    margin-bottom: 20px;
    font-weight: 500;
}

.dashboard-summary {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 20px;
    margin-bottom: 30px;
}

.summary-card {
    background-color: var(--card-background);
    border-radius: 8px;
    padding: 20px;
    box-shadow: var(--shadow);
    display: flex;
    align-items: center;
}

.card-icon {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background-color: rgba(3, 169, 244, 0.1);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-right: 15px;
}

.card-icon i {
    font-size: 24px;
    color: var(--primary-color);
}

.card-content h3 {
    font-size: 16px;
    font-weight: 500;
    margin-bottom: 5px;
    color: var(--text-secondary);
}

.card-content p {
    font-size: 20px;
    font-weight: 500;
}

.card-content p.amount {
    color: var(--primary-color);
}

/* Charts */
.dashboard-charts, .charts-container {
    margin-bottom: 30px;
}

.chart-container, .chart-box {
    background-color: var(--card-background);
    border-radius: 8px;
    padding: 20px;
    box-shadow: var(--shadow);
    margin-bottom: 20px;
}

.chart-container h2, .chart-box h2 {
    font-size: 18px;
    font-weight: 500;
    margin-bottom: 15px;
}

/* Tables */
table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 10px;
}

table th, table td {
    padding: 12px 15px;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

table th {
    font-weight: 500;
    color: var(--text-secondary);
}

table td.amount {
    font-weight: 500;
    color: var(--primary-color);
}

table td.no-data {
    text-align: center;
    color: var(--text-secondary);
    padding: 30px 0;
}

/* Forms */
.form-container {
    background-color: var(--card-background);
    border-radius: 8px;
    padding: 20px;
    box-shadow: var(--shadow);
    margin-bottom: 30px;
}

.form-container h2 {
    font-size: 18px;
    font-weight: 500;
    margin-bottom: 20px;
}

.form-group {
    margin-bottom: 15px;
}

.form-group.inline {
    display: inline-block;
    margin-right: 15px;
}

.form-group label {
    display: block;
    margin-bottom: 5px;
    font-weight: 500;
}

.form-group input, .form-group select {
    width: 100%;
    padding: 10px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    font-size: 14px;
}

.form-actions {
    margin-top: 20px;
}

.button {
    display: inline-block;
    padding: 10px 15px;
    background-color: var(--primary-color);
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    text-decoration: none;
    font-size: 14px;
    font-weight: 500;
    transition: background-color 0.3s;
}

.button:hover {
    background-color: #0288d1;
}

.button.secondary {
    background-color: #9e9e9e;
}

.button.secondary:hover {
    background-color: #757575;
}

.action-button {
    margin-top: 15px;
    text-align: right;
}

/* Error messages */
.error-message {
    background-color: #ffebee;
    color: #c62828;
    padding: 10px;
    border-radius: 4px;
    margin-bottom: 15px;
}

/* Filter container */
.filter-container {
    background-color: var(--card-background);
    border-radius: 8px;
    padding: 20px;
    box-shadow: var(--shadow);
    margin-bottom: 30px;
}

.filter-container h2 {
    font-size: 18px;
    font-weight: 500;
    margin-bottom: 15px;
}

/* Responsive design */
@media (max-width: 768px) {
    .sidebar {
        width: 100%;
        height: auto;
        position: relative;
    }
    
    .main-content {
        margin-left: 0;
    }
    
    .dashboard-summary {
        grid-template-columns: 1fr;
    }
}