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

:root {
    --primary-color: #49b55f;
    --primary-dark: #3a9449;
    --secondary-color: #6c757d;
    --danger-color: #dc3545;
    --background: #f5f5f5;
    --card-background: #ffffff;
    --text-primary: #212529;
    --text-secondary: #6c757d;
    --border-color: #dee2e6;
    --shadow: 0 2px 4px rgba(0,0,0,0.1);
    --shadow-lg: 0 4px 6px rgba(0,0,0,0.1);
}

body {
    font-family: 'Mulish', sans-serif;
    background: var(--background);
    color: var(--text-primary);
    line-height: 1.6;
}

.screen {
    display: none;
}

.screen.active {
    display: block;
}

/* Login Screen */
#login-screen {
    min-height: 100vh;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
}

#login-screen.active {
    display: flex;
}

.login-container {
    background: var(--card-background);
    padding: 2rem;
    border-radius: 0.5rem;
    box-shadow: var(--shadow-lg);
    width: 90%;
    max-width: 25rem;
}

.login-container h1 {
    text-align: center;
    color: var(--primary-color);
    margin-bottom: 2rem;
    font-size: 1.75rem;
}

/* Header */
.header {
    background: var(--card-background);
    padding: 1rem;
    box-shadow: var(--shadow);
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
}

.header h1 {
    color: var(--primary-color);
    font-size: 1.5rem;
}

.header-actions {
    display: flex;
    align-items: center;
    gap: 1rem;
}

/* Navigation */
.nav-tabs {
    background: var(--card-background);
    display: flex;
    overflow-x: auto;
    box-shadow: var(--shadow);
    padding: 0 1rem;
}

.tab-btn {
    background: none;
    border: none;
    padding: 1rem 1.5rem;
    cursor: pointer;
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-family: 'Mulish', sans-serif;
    border-bottom: 2px solid transparent;
    transition: all 0.2s;
    white-space: nowrap;
}

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

.tab-btn.active {
    color: var(--primary-color);
    border-bottom-color: var(--primary-color);
}

/* Main Content */
.main-content {
    padding: 1.5rem;
    max-width: 75rem;
    margin: 0 auto;
}

.page-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
    flex-wrap: wrap;
    gap: 1rem;
}

.page-header h2 {
    color: var(--text-primary);
    font-size: 1.5rem;
}

.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
}

/* Cards Grid */
.cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(18rem, 1fr));
    gap: 1.5rem;
}

.card {
    background: var(--card-background);
    border-radius: 0.5rem;
    padding: 1.5rem;
    box-shadow: var(--shadow);
    transition: box-shadow 0.2s;
}

.card:hover {
    box-shadow: var(--shadow-lg);
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: start;
    margin-bottom: 1rem;
}

.card-title {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
}

.card-body {
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

.card-footer {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.client-documents {
    margin-top: 1rem;
    padding-top: 1rem;
    border-top: 1px solid var(--border-color);
}

.documents-label {
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
    font-size: 0.9rem;
}

.documents-links {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.document-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--primary-color);
    text-decoration: none;
    font-size: 0.9rem;
    padding: 0.5rem;
    border-radius: 0.25rem;
    transition: background-color 0.2s;
}

.document-link:hover {
    background-color: rgba(73, 181, 95, 0.1);
}

.document-link i {
    font-size: 0.85rem;
}

/* Buttons */
.btn {
    padding: 0.625rem 1.25rem;
    border: none;
    border-radius: 0.375rem;
    font-family: 'Mulish', sans-serif;
    font-size: 0.9rem;
    cursor: pointer;
    transition: all 0.2s;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
}

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

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

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

.btn-secondary:hover {
    background: #5a6268;
}

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

.btn-danger:hover {
    background: #c82333;
}

.btn-sm {
    padding: 0.375rem 0.75rem;
    font-size: 0.8rem;
}

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

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

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 0.625rem;
    border: 1px solid var(--border-color);
    border-radius: 0.375rem;
    font-family: 'Mulish', sans-serif;
    font-size: 0.9rem;
}

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

.form-group.invalid input,
.form-group.invalid select,
.form-group.invalid textarea {
    border-color: var(--danger-color);
}

.form-group .field-error {
    margin-top: 0.35rem;
    font-size: 0.85rem;
    color: var(--danger-color);
    display: none;
}

.form-group.invalid .field-error {
    display: block;
}

.form-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(12rem, 1fr));
    gap: 1rem;
}

/* Modal */
.modal-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0,0,0,0.5);
    z-index: 1000;
    align-items: center;
    justify-content: center;
    padding: 1rem;
}

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

.modal {
    background: var(--card-background);
    border-radius: 0.5rem;
    width: 100%;
    max-width: 35rem;
    max-height: 90vh;
    overflow-y: auto;
    box-shadow: var(--shadow-lg);
}

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

.modal-header h3 {
    font-size: 1.25rem;
    color: var(--text-primary);
}

.modal-close {
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-secondary);
    padding: 0;
    width: 2rem;
    height: 2rem;
    display: flex;
    align-items: center;
    justify-content: center;
}

.modal-body {
    padding: 1.5rem;
}

/* File Upload */
.file-upload {
    border: 2px dashed var(--border-color);
    border-radius: 0.375rem;
    padding: 2rem;
    text-align: center;
    cursor: pointer;
    transition: all 0.2s;
}

.file-upload:hover {
    border-color: var(--primary-color);
    background: rgba(73, 181, 95, 0.05);
}

.file-upload.uploaded {
    border-color: var(--primary-color);
    background: rgba(73, 181, 95, 0.05);
}

.file-upload.error {
    border-color: var(--danger-color);
    background: rgba(220, 53, 69, 0.05);
}

.file-upload input[type="file"] {
    display: none;
}

.file-upload-label {
    display: block;
    color: var(--text-secondary);
    cursor: pointer;
}

.file-upload-label i {
    font-size: 2rem;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.file-preview {
    margin-top: 1rem;
}

.file-preview-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    padding: 1rem;
    background: var(--background);
    border-radius: 0.375rem;
}

.file-preview-image {
    max-width: 100%;
    max-height: 12rem;
    border-radius: 0.375rem;
    box-shadow: var(--shadow);
    object-fit: contain;
}

.file-preview-name {
    font-size: 0.875rem;
    color: var(--text-secondary);
    word-break: break-word;
    text-align: center;
}

.file-preview-content i {
    font-size: 3rem;
    color: var(--primary-color);
}

.required {
    color: var(--danger-color);
    font-weight: bold;
}

/* Users Tree */
.users-tree {
    background: var(--card-background);
    padding: 1.5rem;
    border-radius: 0.5rem;
    box-shadow: var(--shadow);
}

.tree-node {
    margin-left: 1.5rem;
    margin-top: 1rem;
    padding-left: 1rem;
    border-left: 2px solid var(--border-color);
}

.tree-node-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.75rem;
    background: var(--background);
    border-radius: 0.375rem;
    margin-bottom: 0.5rem;
}

.tree-node-name {
    font-weight: 600;
    color: var(--text-primary);
}

.tree-node-info {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

/* Payment Schedule */
.payment-schedule {
    margin-top: 1rem;
}

.payment-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.75rem;
    background: var(--background);
    border-radius: 0.375rem;
    margin-bottom: 0.5rem;
}

.payment-item.paid {
    background: rgba(73, 181, 95, 0.1);
}

.payment-item.overdue {
    background: rgba(220, 53, 69, 0.1);
}

/* Status Badges */
.badge {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    border-radius: 1rem;
    font-size: 0.75rem;
    font-weight: 600;
}

.badge-success {
    background: rgba(73, 181, 95, 0.2);
    color: var(--primary-dark);
}

.badge-warning {
    background: rgba(255, 193, 7, 0.2);
    color: #856404;
}

.badge-danger {
    background: rgba(220, 53, 69, 0.2);
    color: var(--danger-color);
}

.badge-info {
    background: rgba(0, 123, 255, 0.2);
    color: #004085;
}

/* Responsive */
@media (max-width: 48rem) {
    .header {
        flex-direction: column;
        align-items: flex-start;
    }

    .page-header {
        flex-direction: column;
        align-items: flex-start;
    }

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

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

    .modal {
        max-width: 100%;
    }
}

/* Loading */
.loading {
    text-align: center;
    padding: 2rem;
    color: var(--text-secondary);
}

/* Empty State */
.empty-state {
    text-align: center;
    padding: 3rem;
    color: var(--text-secondary);
}

.empty-state i {
    font-size: 3rem;
    margin-bottom: 1rem;
    color: var(--border-color);
}

/* Calendar */
.calendar-grid {
    background: var(--card-background);
    border-radius: 0.5rem;
    box-shadow: var(--shadow);
    overflow: hidden;
}

.calendar-header {
    display: grid;
    grid-template-columns: repeat(7, 1fr);
    background: var(--primary-color);
    color: white;
    font-weight: 600;
}

.calendar-day-header {
    padding: 1rem;
    text-align: center;
    border-right: 1px solid rgba(255, 255, 255, 0.2);
}

.calendar-day-header:last-child {
    border-right: none;
}

.calendar-days {
    display: grid;
    grid-template-columns: repeat(7, 1fr);
}

.calendar-day {
    min-height: 6rem;
    padding: 0.5rem;
    border-right: 1px solid var(--border-color);
    border-bottom: 1px solid var(--border-color);
    background: var(--card-background);
    cursor: pointer;
    transition: background-color 0.2s;
}

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

.calendar-day.empty {
    background: var(--background);
    cursor: default;
}

.calendar-day.non-working {
    background: #f8f9fa;
    color: var(--text-secondary);
}

.calendar-day.today {
    background: rgba(73, 181, 95, 0.1);
    border: 2px solid var(--primary-color);
}

.calendar-day-number {
    font-weight: 600;
    margin-bottom: 0.25rem;
}

.calendar-holiday-label {
    font-size: 0.7rem;
    color: var(--text-secondary);
    margin-bottom: 0.25rem;
    font-style: italic;
}

.calendar-payments {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
    margin-top: 0.25rem;
}

.calendar-payment-item {
    padding: 0.25rem 0.5rem;
    border-radius: 0.25rem;
    font-size: 0.75rem;
    cursor: pointer;
    transition: box-shadow 0.2s;
    border-left: 3px solid;
}

.calendar-payment-item:hover {
    box-shadow: var(--shadow);
}

.calendar-payment-item.pending {
    background: rgba(255, 193, 7, 0.1);
    border-left-color: #ffc107;
}

.calendar-payment-item.overdue {
    background: rgba(220, 53, 69, 0.1);
    border-left-color: var(--danger-color);
    color: var(--danger-color);
}

.calendar-payment-item.paid {
    background: rgba(73, 181, 95, 0.1);
    border-left-color: var(--primary-color);
    color: var(--primary-dark);
    opacity: 0.7;
}

.calendar-payment-amount {
    font-weight: 600;
    display: block;
}

.calendar-payment-client {
    font-size: 0.7rem;
    color: var(--text-secondary);
    display: block;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.calendar-day-details {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    margin-top: 1rem;
}

.calendar-detail-item {
    padding: 1rem;
    border-radius: 0.375rem;
    border-left: 3px solid;
}

.calendar-detail-item.pending {
    background: rgba(255, 193, 7, 0.1);
    border-left-color: #ffc107;
}

.calendar-detail-item.overdue {
    background: rgba(220, 53, 69, 0.1);
    border-left-color: var(--danger-color);
}

.calendar-detail-item.paid {
    background: rgba(73, 181, 95, 0.1);
    border-left-color: var(--primary-color);
}

.calendar-detail-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.5rem;
}

.calendar-detail-body {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.calendar-detail-body p {
    margin: 0.25rem 0;
}

@media (max-width: 48rem) {
    .calendar-day {
        min-height: 4rem;
        padding: 0.25rem;
    }
    
    .calendar-day-header {
        padding: 0.5rem;
        font-size: 0.8rem;
    }
    
    .calendar-payment-item {
        font-size: 0.65rem;
        padding: 0.2rem 0.4rem;
    }
    
    .calendar-payment-client {
        display: none;
    }
}