:root {
    --primary: #4f46e5;
    --primary-dark: #4338ca;
    --secondary: #64748b;
    --success: #10b981;
    --danger: #ef4444;
    --warning: #f59e0b;
    --background: #f8fafc;
    --surface: #ffffff;
    --text-main: #1e293b;
    --text-muted: #64748b;
    --border: #e2e8f0;
    --radius: 12px;
    --shadow: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

body {
    background-color: var(--background);
    color: var(--text-main);
    line-height: 1.5;
    padding: 2rem 1rem;
}

.app-container {
    max-width: 1000px;
    margin: 0 auto;
}

/* Header */
header {
    text-align: center;
    margin-bottom: 3rem;
}

.logo {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    margin-bottom: 0.5rem;
}

.logo-icon {
    color: var(--primary);
    width: 32px;
    height: 32px;
}

h1 {
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--primary);
    letter-spacing: -0.025em;
}

.subtitle {
    color: var(--text-muted);
    font-size: 1.1rem;
}

/* Summary Cards */
.summary-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.card {
    background: var(--surface);
    padding: 1.5rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: transform 0.2s, box-shadow 0.2s;
}

.card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.card h3 {
    font-size: 0.875rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 0.5rem;
}

.card p {
    font-size: 1.75rem;
    font-weight: 700;
}

.card i {
    width: 48px;
    height: 48px;
    padding: 10px;
    border-radius: 50%;
}

.card.balance i { background: #e0e7ff; color: var(--primary); }
.card.income i { background: #dcfce7; color: var(--success); }
.card.expense i { background: #fee2e2; color: var(--danger); }

.card.income p { color: var(--success); }
.card.expense p { color: var(--danger); }

/* Dashboard Grid */
.dashboard-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    margin-bottom: 2rem;
}

@media (max-width: 992px) {
    .dashboard-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 640px) {
    body {
        padding: 1rem 0.5rem;
    }

    h1 {
        font-size: 1.75rem;
    }

    .card {
        padding: 1.25rem;
    }

    .card p {
        font-size: 1.5rem;
    }

    .form-row {
        grid-template-columns: 1fr;
        gap: 0;
    }

    .summary-cards {
        grid-template-columns: 1fr;
        gap: 1rem;
    }

    th, td {
        padding: 0.75rem 0.5rem;
        font-size: 0.8125rem;
    }

    #toast-container {
        left: 1rem;
        right: 1rem;
        bottom: 1rem;
    }

    .toast {
        margin-bottom: 0.5rem;
        width: 100%;
    }
}

/* Sections */
section {
    background: var(--surface);
    padding: 1.5rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid var(--border);
}

.section-header h2 {
    font-size: 1.25rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.section-header h2 i {
    color: var(--primary);
}

/* Form Styles */
.form-group {
    margin-bottom: 1.25rem;
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

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

input, select {
    width: 100%;
    padding: 0.875rem;
    border: 1px solid var(--border);
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.2s, ring 0.2s;
    appearance: none;
    background-color: white;
}

select {
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='24' height='24' viewBox='0 0 24 24' fill='none' stroke='%2364748b' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='m6 9 6 6 6-6'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 0.75rem center;
    background-size: 1.25rem;
    padding-right: 2.5rem;
}

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

.btn-primary {
    width: 100%;
    background: var(--primary);
    color: white;
    border: none;
    padding: 0.875rem;
    border-radius: 8px;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    transition: background 0.2s;
}

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

/* Chart Styles */
.chart-container {
    position: relative;
    height: 300px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.hidden {
    display: none;
}

#no-data-message {
    color: var(--text-muted);
    font-style: italic;
}

/* Table Styles */
.list-section {
    margin-top: 2rem;
}

.table-container {
    overflow-x: auto;
}

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

th {
    padding: 1rem;
    font-size: 0.875rem;
    color: var(--text-muted);
    border-bottom: 1px solid var(--border);
    font-weight: 600;
}

td {
    padding: 1rem;
    border-bottom: 1px solid var(--border);
    font-size: 0.9375rem;
}

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

.badge {
    padding: 0.25rem 0.625rem;
    border-radius: 9999px;
    font-size: 0.75rem;
    font-weight: 500;
}

.badge-expense { background: #fee2e2; color: var(--danger); }
.badge-income { background: #dcfce7; color: var(--success); }

.amount-expense { color: var(--danger); font-weight: 600; }
.amount-income { color: var(--success); font-weight: 600; }

.btn-delete {
    background: none;
    border: none;
    color: var(--secondary);
    cursor: pointer;
    padding: 0.6rem;
    border-radius: 6px;
    transition: background 0.2s, color 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
}

.btn-delete:hover {
    background: #fee2e2;
    color: var(--danger);
}

/* Footer */
footer {
    text-align: center;
    margin-top: 4rem;
    color: var(--text-muted);
    font-size: 0.875rem;
}

/* Toast Notification */
#toast-container {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    z-index: 1000;
}

.toast {
    background: var(--surface);
    color: var(--text-main);
    padding: 1rem 1.5rem;
    border-radius: 8px;
    box-shadow: var(--shadow-lg);
    border-left: 4px solid var(--primary);
    margin-bottom: 0.75rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    animation: slideIn 0.3s ease-out;
}

.toast.success { border-left-color: var(--success); }
.toast.error { border-left-color: var(--danger); }

@keyframes slideIn {
    from { transform: translateX(100%); opacity: 0; }
    to { transform: translateX(0); opacity: 1; }
}

/* Animations */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.transaction-item {
    animation: fadeIn 0.3s ease-out forwards;
}