:root {
    --primary: #4F46E5;
    --primary-hover: #4338CA;
    --success: #10B981;
    --success-hover: #059669;
    --danger: #EF4444;
    --bg-color: #F9FAFB;
    --card-bg: #FFFFFF;
    --text-main: #111827;
    --text-muted: #6B7280;
    --border-color: #E5E7EB;
    --radius: 12px;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-hover: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
}

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

body {
    font-family: 'Tiro Bangla', serif;
    background-color: var(--bg-color);
    color: var(--text-main);
    line-height: 1.5;
    padding: 2rem;
}

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

/* Header */
.app-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    padding-bottom: 1.5rem;
    border-bottom: 1px solid var(--border-color);
}

.app-header h1 {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 0.25rem;
}

.app-header p {
    color: var(--text-muted);
}

/* Buttons */
.btn {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: var(--radius);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
}

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

.btn-primary:hover {
    background-color: var(--primary-hover);
    transform: translateY(-1px);
}

.btn-success {
    background-color: var(--success);
    color: white;
    width: 100%;
    margin-top: 1rem;
}

.btn-success:hover {
    background-color: var(--success-hover);
    transform: translateY(-1px);
}

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

.btn-danger:hover {
    background-color: #DC2626;
    transform: translateY(-1px);
}

.delete-btn {
    background: none;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    font-size: 1.1rem;
    padding: 0.25rem;
    transition: color 0.2s;
    line-height: 1;
}

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

/* Layout */
.main-content {
    display: grid;
    grid-template-columns: 350px 1fr;
    gap: 2rem;
}


/* Cards & Forms */
.card {
    background-color: var(--card-bg);
    border-radius: var(--radius);
    padding: 1.5rem;
    box-shadow: var(--shadow);
}

.transaction-section h2 {
    margin-bottom: 1.5rem;
    font-size: 1.25rem;
}

.form-group {
    margin-bottom: 1.25rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    font-size: 0.9rem;
}

.form-group input,
.form-group select {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    font-family: inherit;
    transition: border-color 0.2s;
}

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

/* Dashboard Section */
.dashboard-section h2 {
    margin-bottom: 1rem;
    font-size: 1.5rem;
}

.overview-summary {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.summary-stat {
    background: linear-gradient(135deg, var(--primary) 0%, #312E81 100%);
    padding: 1.5rem;
    border-radius: var(--radius);
    color: white;
    box-shadow: var(--shadow);
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.summary-stat span {
    display: block;
    font-size: 0.875rem;
    opacity: 0.8;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 0.25rem;
}

.summary-stat strong {
    font-size: 1.5rem;
}

.users-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 1.5rem;
}

.user-card {
    background-color: var(--card-bg);
    border-radius: var(--radius);
    padding: 1.5rem;
    box-shadow: var(--shadow);
    transition: transform 0.2s, box-shadow 0.2s;
    border: 1px solid var(--border-color);
}

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

.user-header {
    display: flex;
    align-items: center;
    margin-bottom: 1rem;
    padding-bottom: 0.75rem;
    border-bottom: 1px solid var(--border-color);
}

.user-avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background-color: var(--primary);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    font-size: 1.25rem;
    margin-right: 1rem;
}

.user-name {
    font-weight: 600;
    font-size: 1.1rem;
}

.user-stats {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.stat-row {
    display: flex;
    justify-content: space-between;
    font-size: 0.9rem;
}

.stat-row .label {
    color: var(--text-muted);
}

.balance-row {
    margin-top: 0.5rem;
    padding-top: 0.5rem;
    border-top: 1px dashed var(--border-color);
    font-weight: 700;
    font-size: 1.1rem;
}

.text-positive {
    color: var(--success);
}

.text-negative {
    color: var(--danger);
}

/* Toggle Buttons */
.toggle-group {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.toggle-btn {
    padding: 0.5rem 1rem;
    border: 1px solid var(--border-color);
    background-color: var(--card-bg);
    color: var(--text-main);
    border-radius: 20px;
    cursor: pointer;
    font-size: 0.9rem;
    font-weight: 500;
    transition: all 0.2s;
    user-select: none;
    -webkit-tap-highlight-color: transparent;
}

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

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

.help-text {
    font-size: 0.8rem;
    color: var(--text-muted);
    margin-top: 0.5rem;
}

/* History Section */
.history-list {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.history-item {
    background-color: var(--bg-color);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    padding: 1rem;
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
}

.history-item .history-details {
    flex: 1;
    word-break: break-word;
}

.history-item .history-amount {
    font-size: 1.25rem;
    font-weight: 700;
    margin-left: 1rem;
}

.history-item .history-time {
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-bottom: 0.25rem;
}

.history-item .history-desc {
    font-weight: 600;
    font-size: 1.1rem;
    margin-bottom: 0.25rem;
}

.history-item .history-users {
    font-size: 0.9rem;
    color: var(--text-muted);
}

.history-item .history-location {
    font-size: 0.85rem;
    margin-top: 0.5rem;
}

.history-item .history-location a {
    color: var(--primary);
    text-decoration: none;
    font-weight: 500;
}

.history-item .history-location a:hover {
    text-decoration: underline;
}

/* Modal Styles */
.modal {
    display: none; 
    position: fixed; 
    z-index: 1000; 
    left: 0;
    top: 0;
    width: 100%; 
    height: 100%; 
    overflow: auto; 
    background-color: rgba(0,0,0,0.5); 
    backdrop-filter: blur(4px);
    align-items: center;
    justify-content: center;
}

.modal.show {
    display: flex;
}

.modal-content {
    background-color: var(--card-bg);
    margin: auto;
    padding: 2rem;
    width: 90%;
    max-width: 600px;
    max-height: 90vh;
    overflow-y: auto;
    position: relative;
    border-radius: var(--radius);
    box-shadow: var(--shadow-hover);
}

.close-modal {
    position: absolute;
    right: 1.5rem;
    top: 1.5rem;
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--text-muted);
    cursor: pointer;
    line-height: 1;
}

.close-modal:hover {
    color: var(--danger);
}

.user-card {
    cursor: pointer;
}

@media (max-width: 860px) {
    .main-content {
        grid-template-columns: 1fr;
    }
    .overview-summary {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 600px) {
    body {
        padding: 1rem;
    }
    .history-item {
        flex-direction: column;
        gap: 0.5rem;
    }
    .history-item .history-amount {
        margin-left: 0;
    }
    .modal-content {
        padding: 1.5rem;
    }
    .app-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 1rem;
    }
    #add-user-btn {
        width: 100%;
    }
}

.btn-secondary { background: #e2e8f0; color: #475569; }
.btn-secondary:hover { background: #cbd5e1; }

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
    gap: 1rem;
}
.section-header h2 {
    margin-bottom: 0;
}
@media (max-width: 600px) {
    .section-header {
        flex-direction: column;
        align-items: stretch;
    }
    .section-header h2 {
        text-align: center;
        margin-bottom: 0.5rem;
    }
}