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

:root {
    --primary: #374151;
    --primary-dark: #1f2937;
    --secondary: #6b7280;
    --success: #059669;
    --danger: #dc2626;
    --warning: #d97706;
    --dark: #111827;
    --light: #e5e7eb;
    --white: #ffffff;
    --gray: #9ca3af;
    --shadow: 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: 12px;
    --radius-lg: 16px;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #374151 0%, #1f2937 100%);
    min-height: 100vh;
    color: var(--dark);
    padding: 20px;
}

.container {
    max-width: 480px;
    margin: 0 auto;
    background: var(--white);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    overflow: hidden;
}

.header {
    background: linear-gradient(135deg, var(--primary-dark) 0%, var(--primary) 100%);
    color: var(--white);
    padding: 30px 20px;
    text-align: center;
}

.header h1 {
    font-size: 28px;
    font-weight: 700;
    margin-bottom: 5px;
}

.header p {
    font-size: 14px;
    opacity: 0.9;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 15px;
    padding: 20px;
    background: var(--light);
}

.stat-card {
    background: var(--white);
    padding: 20px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    text-align: center;
    transition: transform 0.3s ease;
}

.stat-card:hover {
    transform: translateY(-5px);
}

.stat-card .label {
    font-size: 12px;
    color: var(--gray);
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 8px;
}

.stat-card .value {
    font-size: 24px;
    font-weight: 700;
    color: var(--primary);
}

.stat-card.today .value {
    color: var(--success);
}

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

.nav-tabs {
    display: flex;
    background: var(--white);
    border-bottom: 2px solid var(--light);
}

.nav-tab {
    flex: 1;
    padding: 15px;
    text-align: center;
    background: none;
    border: none;
    cursor: pointer;
    font-size: 14px;
    font-weight: 600;
    color: var(--gray);
    transition: all 0.3s ease;
    position: relative;
}

.nav-tab.active {
    color: var(--primary);
}

.nav-tab.active::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    right: 0;
    height: 3px;
    background: var(--primary);
}

.nav-tab:hover {
    background: var(--light);
}

.content {
    padding: 20px;
    min-height: 400px;
    overflow: visible;
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: var(--dark);
    font-size: 14px;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 12px 16px;
    border: 2px solid var(--light);
    border-radius: var(--radius);
    font-size: 16px;
    transition: border-color 0.3s ease;
    font-family: inherit;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary);
}

.form-group textarea {
    resize: vertical;
    min-height: 80px;
}

.btn {
    padding: 14px 28px;
    border: none;
    border-radius: var(--radius);
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: var(--white);
    width: 100%;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background: var(--light);
    color: var(--dark);
}

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

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

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

.btn-sm {
    padding: 8px 16px;
    font-size: 14px;
}

.expense-list {
    list-style: none;
}

.expense-item {
    background: var(--white);
    border-radius: var(--radius);
    padding: 16px;
    margin-bottom: 12px;
    box-shadow: var(--shadow);
    display: flex;
    align-items: center;
    gap: 15px;
    transition: transform 0.3s ease;
}

.expense-item:hover {
    transform: translateX(5px);
}

.expense-icon {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    color: var(--white);
    flex-shrink: 0;
}

.expense-details {
    flex: 1;
}

.expense-details .description {
    font-weight: 600;
    color: var(--dark);
    margin-bottom: 4px;
}

.expense-details .category {
    font-size: 12px;
    color: var(--gray);
}

.expense-details .date {
    font-size: 11px;
    color: var(--gray);
}

.expense-amount {
    font-size: 20px;
    font-weight: 700;
    color: var(--danger);
}

.expense-actions {
    display: flex;
    gap: 8px;
}

.expense-actions button {
    padding: 8px;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
}

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

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

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

.chart-container h3 {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 15px;
    color: var(--dark);
}

.category-bar {
    display: flex;
    align-items: center;
    margin-bottom: 12px;
}

.category-bar .label {
    width: 100px;
    font-size: 12px;
    font-weight: 600;
    color: var(--dark);
}

.category-bar .bar {
    flex: 1;
    height: 24px;
    background: var(--light);
    border-radius: 12px;
    overflow: hidden;
    margin: 0 10px;
}

.category-bar .bar-fill {
    height: 100%;
    border-radius: 12px;
    transition: width 0.5s ease;
}

.category-bar .amount {
    font-size: 14px;
    font-weight: 600;
    color: var(--dark);
    min-width: 60px;
    text-align: right;
}

.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    align-items: center;
    justify-content: center;
    z-index: 1000;
    padding: 20px;
}

.modal.active {
    display: flex;
}

.modal-content {
    background: var(--white);
    border-radius: var(--radius-lg);
    padding: 30px;
    max-width: 400px;
    width: 100%;
    max-height: 90vh;
    overflow-y: auto;
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

.modal-header h2 {
    font-size: 20px;
    font-weight: 700;
    color: var(--dark);
}

.modal-close {
    background: none;
    border: none;
    font-size: 24px;
    cursor: pointer;
    color: var(--gray);
    transition: color 0.3s ease;
}

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

.empty-state {
    text-align: center;
    padding: 60px 20px;
    color: var(--gray);
}

.empty-state i {
    font-size: 60px;
    margin-bottom: 20px;
    opacity: 0.5;
}

.empty-state h3 {
    font-size: 18px;
    margin-bottom: 10px;
}

.empty-state p {
    font-size: 14px;
}

.loading {
    text-align: center;
    padding: 40px;
    color: var(--gray);
}

.loading::after {
    content: '';
    display: inline-block;
    width: 30px;
    height: 30px;
    border: 3px solid var(--light);
    border-top-color: var(--primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

.calendar-container {
    background: var(--white);
    border-radius: var(--radius);
    padding: 20px;
    margin-bottom: 20px;
    box-shadow: var(--shadow);
}

.calendar-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

.calendar-header h3 {
    font-size: 18px;
    font-weight: 700;
    color: var(--dark);
    text-align: center;
    flex: 1;
}

.calendar-grid {
    display: grid;
    grid-template-columns: repeat(7, 1fr);
    gap: 5px;
    margin-bottom: 20px;
}

.calendar-day-header {
    text-align: center;
    font-size: 12px;
    font-weight: 600;
    color: var(--gray);
    padding: 8px 4px;
    text-transform: uppercase;
}

.calendar-day {
    aspect-ratio: 1;
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    justify-content: flex-start;
    padding: 6px;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    background: var(--light);
    font-size: 12px;
    font-weight: 600;
    color: var(--dark);
    position: relative;
    min-height: 100px;
    height: 100px;
    overflow: hidden;
    width: 100%;
}

.calendar-day:hover {
    background: var(--primary);
    color: var(--white);
}

.calendar-day.today {
    background: linear-gradient(135deg, var(--primary-dark) 0%, var(--primary) 100%);
    color: var(--white);
    box-shadow: 0 0 0 3px var(--white), 0 0 0 5px var(--primary);
    font-weight: 700;
    position: relative;
}

.calendar-day.today::after {
    content: 'HOY';
    position: absolute;
    top: 4px;
    right: 4px;
    font-size: 8px;
    font-weight: 700;
    background: var(--danger);
    color: var(--white);
    padding: 2px 5px;
    border-radius: 4px;
    letter-spacing: 0.5px;
}

.calendar-day.today:hover {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    transform: scale(1.02);
}

.calendar-day.selected {
    background: var(--primary-dark);
    color: var(--white);
    box-shadow: var(--shadow);
}

.calendar-day.has-expenses {
    border: 2px solid var(--secondary);
}

.calendar-day .expense-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--danger);
    margin-top: 4px;
}

.calendar-day .expense-amount {
    font-size: 10px;
    margin-top: 2px;
    color: var(--danger);
    font-weight: 700;
}

.calendar-day.selected .expense-amount {
    color: var(--white);
}

.calendar-day .expense-item {
    background: rgba(255, 255, 255, 0.5);
    border-radius: 4px;
    padding: 4px;
    margin-top: 4px;
    font-size: 9px;
    display: flex;
    align-items: center;
    gap: 4px;
    width: 100%;
}

.calendar-day .expense-item .expense-icon {
    width: 16px;
    height: 16px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 8px;
    color: var(--white);
    flex-shrink: 0;
}

.calendar-day .expense-item .expense-desc {
    flex: 1;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    color: var(--dark);
}

.calendar-day .expense-item .expense-monto {
    font-weight: 700;
    color: var(--danger);
    font-size: 8px;
}

.calendar-day.selected .expense-item {
    background: rgba(255, 255, 255, 0.2);
}

.calendar-day.selected .expense-item .expense-desc {
    color: var(--white);
}

.calendar-day.selected .expense-item .expense-monto {
    color: var(--white);
}

.calendar-day.empty {
    background: transparent;
    cursor: default;
}

.calendar-day.empty:hover {
    background: transparent;
}

.calendar-expenses {
    background: var(--white);
    border-radius: var(--radius);
    padding: 20px;
    box-shadow: var(--shadow);
}

.calendar-expenses h3 {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 15px;
    color: var(--dark);
}

.calendar-expenses .date-header {
    font-size: 14px;
    font-weight: 600;
    color: var(--primary);
    margin-bottom: 15px;
    padding-bottom: 10px;
    border-bottom: 2px solid var(--light);
}

.calendar-modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    align-items: center;
    justify-content: center;
    z-index: 2000;
    padding: 20px;
}

.calendar-modal.active {
    display: flex;
}

.calendar-modal-content {
    background: var(--white);
    border-radius: var(--radius-lg);
    padding: 25px;
    max-width: 500px;
    width: 100%;
    max-height: 90vh;
    overflow-y: auto;
}

.calendar-modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    padding-bottom: 15px;
    border-bottom: 2px solid var(--light);
}

.calendar-modal-header h3 {
    font-size: 18px;
    font-weight: 700;
    color: var(--dark);
    margin: 0;
}

.calendar-modal-close {
    background: none;
    border: none;
    font-size: 24px;
    cursor: pointer;
    color: var(--gray);
    transition: color 0.3s ease;
}

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

.calendar-modal-date {
    font-size: 14px;
    font-weight: 600;
    color: var(--primary);
    margin-bottom: 15px;
}

.calendar-modal-total {
    font-size: 16px;
    font-weight: 700;
    color: var(--danger);
    margin-bottom: 20px;
}

.calendar-modal-expenses {
    list-style: none;
}

.calendar-modal-expenses li {
    background: var(--light);
    border-radius: var(--radius);
    padding: 15px;
    margin-bottom: 10px;
    display: flex;
    align-items: center;
    gap: 15px;
}

.calendar-modal-expenses .expense-icon {
    width: 45px;
    height: 45px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 18px;
    color: var(--white);
    flex-shrink: 0;
}

.calendar-modal-expenses .expense-details {
    flex: 1;
}

.calendar-modal-expenses .expense-details .description {
    font-weight: 600;
    color: var(--dark);
    margin-bottom: 4px;
}

.calendar-modal-expenses .expense-details .category {
    font-size: 12px;
    color: var(--gray);
}

.calendar-modal-expenses .expense-amount {
    font-size: 18px;
    font-weight: 700;
    color: var(--danger);
}

@media (max-width: 480px) {
    body {
        padding: 10px;
    }
    
    .header h1 {
        font-size: 24px;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
    
    .expense-item {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .expense-amount {
        align-self: flex-end;
    }
    
    .expense-actions {
        width: 100%;
        justify-content: flex-end;
    }
}