:root {
    --primary-color: #4f46e5;
    --primary-hover: #4338ca;
    --secondary-color: #10b981;
    --bg-color: #f3f4f6;
    --card-bg: #ffffff;
    --text-main: #1f2937;
    --text-muted: #6b7280;
    --border-color: #e5e7eb;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --radius: 0.75rem;
}

* {
    box-sizing: border-box;
}

body {
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-main);
    margin: 0;
    padding: 0;
    line-height: 1.5;
}

/* Layout */
.app-container {
    display: flex;
    min-height: 100vh;
}

.sidebar {
    width: 260px;
    background-color: var(--card-bg);
    border-right: 1px solid var(--border-color);
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
    position: fixed;
    height: 100%;
    top: 0;
    left: 0;
    overflow-y: auto;
    z-index: 50;
}

.main-content {
    flex: 1;
    margin-left: 260px;
    padding: 2rem;
}

/* Sidebar */
.brand {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--primary-color);
    margin-bottom: 2rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-menu {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.nav-link {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem 1rem;
    border-radius: var(--radius);
    color: var(--text-muted);
    text-decoration: none;
    font-weight: 500;
    transition: all 0.2s;
}

.nav-link:hover,
.nav-link.active {
    background-color: #eef2ff;
    color: var(--primary-color);
}

.nav-link i {
    font-size: 1.25rem;
}

/* Cards */
.card {
    background: var(--card-bg);
    border-radius: var(--radius);
    box-shadow: var(--shadow-sm);
    padding: 1.5rem;
    border: 1px solid var(--border-color);
    margin-bottom: 1.5rem;
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
}

.card-title {
    font-size: 1.125rem;
    font-weight: 600;
    margin: 0;
}

/* Stats Grid */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.stat-card {
    background: var(--card-bg);
    padding: 1.5rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
}

.stat-label {
    color: var(--text-muted);
    font-size: 0.875rem;
    font-weight: 500;
    margin-bottom: 0.5rem;
}

.stat-value {
    font-size: 1.875rem;
    font-weight: 700;
    color: var(--text-main);
}

.stat-value.profit {
    color: var(--secondary-color);
}

.stat-value.expense {
    color: #ef4444;
}

/* Tables */
.table-container {
    overflow-x: auto;
}

table {
    width: 100%;
    border-collapse: collapse;
    text-align: left;
}

th {
    background-color: #f9fafb;
    padding: 0.75rem 1rem;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    color: var(--text-muted);
    letter-spacing: 0.05em;
    border-bottom: 1px solid var(--border-color);
}

td {
    padding: 1rem;
    border-bottom: 1px solid var(--border-color);
    color: var(--text-main);
}

tr:last-child td {
    border-bottom: none;
}

/* Forms */
.form-group {
    margin-bottom: 1rem;
}

.form-label {
    display: block;
    font-size: 0.875rem;
    font-weight: 500;
    margin-bottom: 0.5rem;
    color: var(--text-main);
}

.form-control {
    width: 100%;
    padding: 0.625rem 0.875rem;
    border-radius: 0.5rem;
    border: 1px solid var(--border-color);
    font-size: 0.95rem;
    transition: border-color 0.2s;
    box-sizing: border-box;
}

.form-control:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.625rem 1.25rem;
    border-radius: 0.5rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    border: none;
    text-decoration: none;
    gap: 0.5rem;
}

.btn-primary {
    background-color: var(--primary-color);
    color: white;
}

.btn-primary:hover {
    background-color: var(--primary-hover);
}

.btn-success {
    background-color: var(--secondary-color);
    color: white;
}

.btn-sm {
    padding: 0.375rem 0.75rem;
    font-size: 0.875rem;
}

/* Utilities */
.text-right {
    text-align: right;
}

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

.mt-4 {
    margin-top: 1.5rem;
}

.mb-4 {
    margin-bottom: 1.5rem;
}

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

/* Responsive */
@media (max-width: 768px) {
    .sidebar {
        width: 70px;
        padding: 1rem 0.5rem;
    }

    .brand span,
    .nav-link span {
        display: none;
    }

    .main-content {
        margin-left: 70px;
        padding: 1rem;
    }

    .nav-link {
        justify-content: center;
        padding: 0.75rem;
    }
}