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

:root {
    /* Light mode colors (default) */
    --bg-primary: #f5f5f5;
    --bg-secondary: #ffffff;
    --bg-tertiary: #f8f9fa;
    --bg-hover: #f8f9fa;
    --text-primary: #333;
    --text-secondary: #2c3e50;
    --text-tertiary: #666;
    --text-muted: #7f8c8d;
    --border-color: #ecf0f1;
    --border-dark: #ddd;
    --shadow: rgba(0,0,0,0.1);
    --table-header: #34495e;
    --input-bg: #ffffff;
    --input-border: #ddd;
    --editable-bg: #f8f9fa;
    --editable-hover: #e9ecef;
    --calculated-bg: #ecf0f1;
    --current-day-bg: #fff9e6;
    --current-day-hover: #fff3d4;
    --current-day-border: #f39c12;
    --future-opacity: 0.5;
    --modal-overlay: rgba(0,0,0,0.4);
    --modal-bg: #fefefe;
    --modal-border: #888;
}

@media (prefers-color-scheme: dark) {
    :root {
        /* Dark mode colors */
        --bg-primary: #1a1a1a;
        --bg-secondary: #2d2d2d;
        --bg-tertiary: #363636;
        --bg-hover: #3a3a3a;
        --text-primary: #e0e0e0;
        --text-secondary: #ffffff;
        --text-tertiary: #b0b0b0;
        --text-muted: #888888;
        --border-color: #404040;
        --border-dark: #4a4a4a;
        --shadow: rgba(0,0,0,0.3);
        --table-header: #1f2937;
        --input-bg: #2d2d2d;
        --input-border: #4a4a4a;
        --editable-bg: #363636;
        --editable-hover: #3a3a3a;
        --calculated-bg: #323232;
        --current-day-bg: #3d3520;
        --current-day-hover: #4a3f26;
        --current-day-border: #f39c12;
        --future-opacity: 0.4;
        --modal-overlay: rgba(0,0,0,0.6);
        --modal-bg: #2d2d2d;
        --modal-border: #555;
    }
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 20px;
}

header {
    background: var(--bg-secondary);
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 4px var(--shadow);
    margin-bottom: 20px;
}

.header-top {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 15px;
}

header h1 {
    margin: 0;
    color: var(--text-secondary);
}

.user-menu {
    display: flex;
    align-items: center;
    gap: 15px;
}

.user-menu .username {
    font-weight: 600;
    color: var(--text-secondary);
}

.user-menu .logout-btn {
    padding: 6px 16px;
    background: #e74c3c;
    color: white;
    text-decoration: none;
    border-radius: 4px;
    font-size: 14px;
    transition: background 0.3s;
}

.user-menu .logout-btn:hover {
    background: #c0392b;
}

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

.nav-btn {
    padding: 8px 16px;
    background: #3498db;
    color: white;
    text-decoration: none;
    border-radius: 4px;
    transition: background 0.3s;
}

.nav-btn:hover {
    background: #2980b9;
}

.summary {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 15px;
    margin-bottom: 20px;
}

.summary-item {
    background: var(--bg-secondary);
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 4px var(--shadow);
}

.summary-item label {
    display: block;
    font-size: 0.9em;
    color: var(--text-tertiary);
    margin-bottom: 5px;
}

.summary-item span {
    display: block;
    font-size: 1.8em;
    font-weight: bold;
    color: var(--text-secondary);
}

.summary-item.positive span {
    color: #27ae60;
}

.summary-item.negative span {
    color: #e74c3c;
}

.table-container {
    background: var(--bg-secondary);
    border-radius: 8px;
    box-shadow: 0 2px 4px var(--shadow);
    overflow-x: auto;
    margin-bottom: 20px;
}

.timesheet-table {
    width: 100%;
    border-collapse: collapse;
}

.timesheet-table thead {
    background: var(--table-header);
    color: white;
}

.timesheet-table th,
.timesheet-table td {
    padding: 12px;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.timesheet-table tbody tr:hover {
    background: var(--bg-hover);
}

.timesheet-table tbody tr.week-start {
    border-top: 3px solid var(--table-header);
}

.timesheet-table tbody tr.current-day {
    background-color: var(--current-day-bg);
    border-left: 4px solid var(--current-day-border);
}

.timesheet-table tbody tr.current-day:hover {
    background-color: var(--current-day-hover);
}

.timesheet-table td.positive {
    color: #27ae60;
    font-weight: bold;
}

.timesheet-table td.warning {
    color: #f39c12;
    font-weight: bold;
}

.timesheet-table td.negative {
    color: #e74c3c;
    font-weight: bold;
}

.timesheet-table tfoot {
    border-top: 3px double var(--text-secondary);
}

.timesheet-table .totals-row td {
    font-weight: bold;
    background-color: var(--bg-tertiary);
    padding: 12px 8px;
}

/* Client selector */
.client-selector {
    margin: 20px 0;
    display: flex;
    align-items: center;
    gap: 10px;
}

.client-selector label {
    font-weight: 600;
    color: var(--text-secondary);
}

.client-selector select {
    padding: 8px 12px;
    border: 1px solid var(--border-dark);
    border-radius: 4px;
    font-size: 16px;
    font-family: inherit;
    min-width: 200px;
    background: var(--input-bg);
    color: var(--text-primary);
}

.nav-links {
    margin: 10px 0;
}

.nav-links a {
    color: #3498db;
    text-decoration: none;
    padding: 8px 16px;
    border: 1px solid #3498db;
    border-radius: 4px;
    transition: all 0.3s ease;
}

.nav-links a:hover {
    background-color: #3498db;
    color: white;
}

/* Client badges */
.badge-active {
    background-color: #27ae60;
    color: white;
    padding: 4px 8px;
    border-radius: 4px;
    font-size: 12px;
    font-weight: bold;
}

.badge-inactive {
    background-color: #95a5a6;
    color: white;
    padding: 4px 8px;
    border-radius: 4px;
    font-size: 12px;
    font-weight: bold;
}

/* Empty state */
.empty-state {
    text-align: center;
    padding: 80px 20px;
    max-width: 600px;
    margin: 0 auto;
}

.empty-state-icon {
    font-size: 64px;
    margin-bottom: 20px;
}

.empty-state h2 {
    color: var(--text-secondary);
    margin-bottom: 16px;
}

.empty-state p {
    color: var(--text-muted);
    font-size: 16px;
    line-height: 1.6;
    margin-bottom: 32px;
}

.btn-primary {
    display: inline-block;
    background-color: #27ae60;
    color: white;
    padding: 12px 32px;
    border-radius: 6px;
    text-decoration: none;
    font-weight: 600;
    transition: background-color 0.3s ease;
}

.btn-primary:hover {
    background-color: #229954;
}

.btn-add {
    position: fixed;
    bottom: 30px;
    right: 30px;
    padding: 16px 32px;
    background: #27ae60;
    color: white;
    border: none;
    border-radius: 50px;
    font-size: 1.1em;
    font-weight: bold;
    cursor: pointer;
    transition: all 0.3s;
    box-shadow: 0 4px 12px rgba(0,0,0,0.2);
    z-index: 100;
}

.btn-add:hover {
    background: #229954;
    transform: scale(1.05);
    box-shadow: 0 6px 16px rgba(0,0,0,0.3);
}

.btn-edit {
    padding: 6px 12px;
    background: #3498db;
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    transition: background 0.3s;
}

.btn-edit:hover {
    background: #2980b9;
}

.btn-save {
    padding: 6px 12px;
    background: #27ae60;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 1.2em;
    transition: transform 0.2s;
}

.btn-save:hover {
    transform: scale(1.1);
}

/* Modal styles */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    overflow: auto;
    background-color: var(--modal-overlay);
}

.modal-content {
    background-color: var(--modal-bg);
    margin: 5% auto;
    padding: 20px;
    border: 1px solid var(--modal-border);
    border-radius: 8px;
    width: 90%;
    max-width: 600px;
}

.close {
    color: var(--text-muted);
    float: right;
    font-size: 28px;
    font-weight: bold;
    cursor: pointer;
}

.close:hover,
.close:focus {
    color: var(--text-primary);
}

.form-group {
    margin-bottom: 15px;
}

.form-group label {
    display: block;
    margin-bottom: 5px;
    font-weight: 500;
    color: var(--text-primary);
}

.form-group small {
    display: block;
    margin-top: 4px;
    color: var(--text-tertiary);
    font-size: 0.85em;
}

.form-group input,
.form-group select {
    width: 100%;
    padding: 8px;
    border: 1px solid var(--border-dark);
    border-radius: 4px;
    font-size: 1em;
    background: var(--input-bg);
    color: var(--text-primary);
}

.form-group input:focus {
    outline: none;
    border-color: #3498db;
    box-shadow: 0 0 0 2px rgba(52, 152, 219, 0.2);
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 15px;
}

.form-actions {
    display: flex;
    justify-content: flex-end;
    gap: 10px;
    margin-top: 20px;
}

.btn-secondary {
    padding: 10px 20px;
    background: #95a5a6;
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 1em;
}

.btn-secondary:hover {
    background: #7f8c8d;
}

.timesheet-table .editable {
    cursor: text;
    background: var(--editable-bg);
    transition: background 0.2s;
}

.timesheet-table .editable:hover {
    background: var(--editable-hover);
}

.timesheet-table .editable:focus {
    background: var(--bg-secondary);
    outline: 2px solid #3498db;
}

.timesheet-table .editable-select select {
    width: 100%;
    padding: 4px;
    border: 1px solid var(--border-dark);
    border-radius: 4px;
    background: var(--input-bg);
    color: var(--text-primary);
    font-size: 14px;
    font-family: inherit;
}

.timesheet-table .calculated {
    background: var(--calculated-bg);
    font-weight: 500;
}

.timesheet-table .future-date {
    opacity: var(--future-opacity);
}

.timesheet-table .future-date .editable {
    background: var(--editable-bg);
}

.timesheet-table .future-date:hover {
    opacity: 0.7;
}

.timesheet-table .actions-cell {
    width: 80px;
    text-align: center;
}

.btn-delete {
    padding: 4px 8px;
    background: transparent;
    border: none;
    cursor: pointer;
    font-size: 1.2em;
    opacity: 0.5;
    transition: opacity 0.2s, transform 0.2s;
}

.btn-delete:hover {
    opacity: 1;
    transform: scale(1.2);
}

@keyframes flash-green {
    0%, 100% { background-color: transparent; }
    50% { background-color: #d4edda; }
}

/* Time Blocks */
.time-blocks-container {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.time-block {
    display: flex;
    align-items: center;
    gap: 8px;
}

.time-input {
    width: 70px;
    padding: 4px 8px;
    border: 1px solid var(--input-border);
    border-radius: 4px;
    font-size: 14px;
    font-family: inherit;
    text-align: center;
    transition: border-color 0.2s, box-shadow 0.2s;
    background: var(--input-bg);
    color: var(--text-primary);
}

.time-input:focus {
    outline: none;
    border-color: #3498db;
    box-shadow: 0 0 0 2px rgba(52, 152, 219, 0.2);
}

.time-input::placeholder {
    color: var(--text-muted);
    opacity: 0.5;
}

.time-separator {
    color: var(--text-muted);
    font-weight: bold;
}

.btn-add-block {
    padding: 0px 4px;
    background: transparent;
    border: none;
    cursor: pointer;
    font-size: 0.85em;
    color: #27ae60;
    opacity: 0.6;
    transition: opacity 0.2s;
    line-height: 1;
}

.btn-add-block:hover {
    opacity: 1;
}

.btn-remove-block {
    padding: 0px 4px;
    background: transparent;
    border: none;
    cursor: pointer;
    font-size: 0.85em;
    color: #e74c3c;
    opacity: 0.5;
    transition: opacity 0.2s;
    line-height: 1;
}

.btn-remove-block:hover {
    opacity: 1;
}

/* Mobile layout - hidden by default */
.mobile-timesheet {
    display: none;
}

/* Footer */
.footer {
    text-align: center;
    padding: 20px;
    margin-top: 40px;
    color: var(--text-muted);
    font-size: 0.9em;
    border-top: 1px solid var(--border-color);
}

.footer-content {
    display: flex;
    flex-direction: column;
    gap: 5px;
}

.footer a {
    color: #3498db;
    text-decoration: none;
}

.footer a:hover {
    text-decoration: underline;
}

/* Mobile Responsive Styles - Target smartphones only */
@media (max-width: 640px) {
    .container {
        padding: 10px;
    }

    header {
        padding: 15px;
    }

    .header-top {
        flex-direction: column;
        gap: 10px;
        align-items: flex-start;
    }

    header h1 {
        font-size: 1.3em;
    }

    .user-menu {
        width: 100%;
        justify-content: space-between;
    }

    .month-nav {
        flex-direction: column;
        gap: 10px;
    }

    .month-nav h2 {
        order: -1;
        font-size: 1.2em;
    }

    .month-nav .nav-btn {
        width: 100%;
        text-align: center;
    }

    .client-selector {
        flex-wrap: wrap;
        gap: 8px;
    }

    .client-selector label {
        width: 100%;
    }

    .client-selector select {
        width: 100%;
        min-width: unset;
    }

    .summary-item {
        padding: 15px;
    }

    .summary-item span {
        font-size: 1.5em;
    }

    .btn-add {
        bottom: 20px;
        right: 20px;
        padding: 14px 24px;
        font-size: 1em;
    }

    /* Hide table on mobile */
    .table-container {
        display: none;
    }

    /* Show card layout on mobile */
    .mobile-timesheet {
        display: block;
    }

    .timesheet-card {
        background: var(--bg-secondary);
        border-radius: 8px;
        padding: 16px;
        margin-bottom: 12px;
        box-shadow: 0 2px 4px var(--shadow);
        border-left: 4px solid var(--border-color);
    }

    .timesheet-card.current-day {
        background-color: var(--current-day-bg);
        border-left-color: var(--current-day-border);
    }

    .timesheet-card.week-start {
        margin-top: 24px;
        border-top: 3px solid var(--table-header);
        padding-top: 20px;
    }

    .timesheet-card.week-start:first-child {
        margin-top: 0;
    }

    .timesheet-card.future-date {
        opacity: var(--future-opacity);
    }

    .card-header {
        display: flex;
        justify-content: space-between;
        align-items: center;
        margin-bottom: 12px;
        padding-bottom: 8px;
        border-bottom: 1px solid var(--border-color);
    }

    .card-date {
        font-weight: 600;
        font-size: 1.05em;
        color: var(--text-secondary);
    }

    .card-delete {
        padding: 4px 8px;
        background: transparent;
        border: none;
        cursor: pointer;
        font-size: 1.2em;
        opacity: 0.5;
        transition: opacity 0.2s, transform 0.2s;
    }

    .card-delete:hover {
        opacity: 1;
        transform: scale(1.2);
    }

    .card-field {
        margin-bottom: 10px;
    }

    .card-field-label {
        display: block;
        font-size: 0.85em;
        color: var(--text-tertiary);
        margin-bottom: 4px;
        font-weight: 500;
    }

    .card-field-value {
        display: block;
        padding: 8px 10px;
        background: var(--editable-bg);
        border-radius: 4px;
        border: 1px solid var(--border-color);
        min-height: 36px;
    }

    .card-field-value:focus {
        background: var(--bg-secondary);
        outline: 2px solid #3498db;
        border-color: #3498db;
    }

    .card-field-value.calculated {
        background: var(--calculated-bg);
        font-weight: 500;
        cursor: default;
    }

    .card-field-value.positive {
        color: #27ae60;
        font-weight: bold;
    }

    .card-field-value.warning {
        color: #f39c12;
        font-weight: bold;
    }

    .card-field-value.negative {
        color: #e74c3c;
        font-weight: bold;
    }

    .card-field select {
        width: 100%;
        padding: 8px 10px;
        border: 1px solid var(--border-dark);
        border-radius: 4px;
        background: var(--input-bg);
        color: var(--text-primary);
        font-size: 14px;
        font-family: inherit;
    }

    .card-time-blocks {
        margin-top: 4px;
    }

    .card-time-blocks .time-block {
        margin-bottom: 8px;
        padding: 8px;
        background: var(--bg-tertiary);
        border-radius: 4px;
    }

    .card-summary {
        display: grid;
        grid-template-columns: repeat(3, 1fr);
        gap: 8px;
        margin-top: 12px;
        padding-top: 12px;
        border-top: 1px solid var(--border-color);
    }

    .card-summary-item {
        text-align: center;
    }

    .card-summary-label {
        display: block;
        font-size: 0.75em;
        color: var(--text-tertiary);
        margin-bottom: 2px;
    }

    .card-summary-value {
        display: block;
        font-weight: 600;
        font-size: 0.95em;
    }
}


/* Offline indicator */
.offline-indicator {
    position: fixed;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    padding: 12px 24px;
    border-radius: 8px;
    font-weight: 500;
    font-size: 14px;
    box-shadow: 0 4px 12px var(--shadow);
    z-index: 1000;
    animation: slideUp 0.3s ease-out;
}

@keyframes slideUp {
    from {
        transform: translateX(-50%) translateY(100px);
        opacity: 0;
    }
    to {
        transform: translateX(-50%) translateY(0);
        opacity: 1;
    }
}

.offline-indicator.offline {
    background: #e74c3c;
    color: white;
}

.offline-indicator.online {
    background: #27ae60;
    color: white;
}

.offline-indicator.syncing {
    background: #3498db;
    color: white;
}

.offline-indicator.synced {
    background: #27ae60;
    color: white;
}