/* ===== VARIABLES CSS ===== */
:root {
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --secondary-color: #64748b;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --danger-color: #ef4444;
    --bg-color: #f8fafc;
    --surface-color: #ffffff;
    --border-color: #e2e8f0;
    --text-primary: #0f172a;
    --text-secondary: #64748b;
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

/* ===== RESET & BASE ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

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

/* ===== LAYOUT ===== */
#app {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.app-header {
    background: var(--surface-color);
    border-bottom: 1px solid var(--border-color);
    padding: 0 2rem;
    box-shadow: var(--shadow);
}

.header-content {
    max-width: 1400px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 64px;
}

.logo {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--primary-color);
}

.nav-menu {
    display: flex;
    gap: 0.5rem;
    list-style: none;
}

.nav-item {
    padding: 0.5rem 1rem;
    border-radius: 6px;
    cursor: pointer;
    transition: background-color 0.2s;
    color: var(--text-secondary);
    font-weight: 500;
}

.nav-item:hover {
    background-color: var(--bg-color);
}

.nav-item.active {
    background-color: var(--primary-color);
    color: white;
}

.user-info {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.user-badge {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background: var(--bg-color);
    border-radius: 6px;
    font-size: 0.875rem;
}

.role-tag {
    padding: 0.25rem 0.5rem;
    background: var(--primary-color);
    color: white;
    border-radius: 4px;
    font-size: 0.75rem;
    font-weight: 600;
}

.main-content {
    flex: 1;
    max-width: 1400px;
    width: 100%;
    margin: 0 auto;
    padding: 2rem;
}

/* ===== LOGIN PAGE ===== */
.login-container {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    padding: 2rem;
}

.login-card {
    background: var(--surface-color);
    padding: 3rem;
    border-radius: 12px;
    box-shadow: var(--shadow-lg);
    width: 100%;
    max-width: 400px;
}

.login-header {
    text-align: center;
    margin-bottom: 2rem;
}

.login-header h1 {
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.login-header p {
    color: var(--text-secondary);
    font-size: 0.875rem;
}

/* ===== FORMS ===== */
.form-group {
    margin-bottom: 1.5rem;
}

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

.form-input,
.form-select {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    font-size: 1rem;
    transition: border-color 0.2s;
}

.form-input:focus,
.form-select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.form-input.error {
    border-color: var(--danger-color);
}

.form-error {
    color: var(--danger-color);
    font-size: 0.875rem;
    margin-top: 0.25rem;
}

/* ===== BUTTONS ===== */
.btn {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 6px;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    justify-content: center;
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

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

.btn-primary:hover:not(:disabled) {
    background: var(--primary-hover);
}

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

.btn-secondary:hover:not(:disabled) {
    background: #475569;
}

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

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

.btn-outline {
    background: transparent;
    border: 1px solid var(--border-color);
    color: var(--text-primary);
}

.btn-outline:hover:not(:disabled) {
    background: var(--bg-color);
}

.btn-full {
    width: 100%;
}

.btn-sm {
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
}

/* ===== ALERTS ===== */
.alert {
    padding: 1rem;
    border-radius: 6px;
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.alert-error {
    background: #fef2f2;
    color: #991b1b;
    border: 1px solid #fecaca;
}

.alert-success {
    background: #f0fdf4;
    color: #166534;
    border: 1px solid #bbf7d0;
}

.alert-warning {
    background: #fffbeb;
    color: #92400e;
    border: 1px solid #fde68a;
}

/* ===== CARDS ===== */
.card {
    background: var(--surface-color);
    border-radius: 8px;
    box-shadow: var(--shadow);
    padding: 1.5rem;
    margin-bottom: 1.5rem;
}

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

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

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

/* ===== TABLES ===== */
.table-container {
    overflow-x: auto;
    margin-top: 1rem;
}

table {
    width: 100%;
    border-collapse: collapse;
    background: var(--surface-color);
}

thead {
    background: var(--bg-color);
}

th {
    padding: 0.75rem;
    text-align: left;
    font-weight: 600;
    font-size: 0.875rem;
    color: var(--text-secondary);
    border-bottom: 2px solid var(--border-color);
}

td {
    padding: 0.75rem;
    border-bottom: 1px solid var(--border-color);
}

tr:hover {
    background: var(--bg-color);
}

/* ===== TIMESHEET SPECIFIC ===== */
.timesheet-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    flex-wrap: wrap;
    gap: 1rem;
}

.month-selector {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.month-selector h2 {
    margin: 0;
}

.timesheet-controls {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.toggle-switch {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    cursor: pointer;
}

.toggle-switch input[type="checkbox"] {
    width: 44px;
    height: 24px;
    position: relative;
    appearance: none;
    background: var(--border-color);
    border-radius: 12px;
    cursor: pointer;
    transition: background 0.2s;
}

.toggle-switch input[type="checkbox"]:checked {
    background: var(--primary-color);
}

.toggle-switch input[type="checkbox"]::before {
    content: '';
    position: absolute;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: white;
    top: 2px;
    left: 2px;
    transition: transform 0.2s;
}

.toggle-switch input[type="checkbox"]:checked::before {
    transform: translateX(20px);
}

.completeness-indicator {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem 1rem;
    background: var(--bg-color);
    border-radius: 6px;
    font-weight: 500;
}

.completeness-indicator.complete {
    background: #f0fdf4;
    color: #166534;
}

.completeness-indicator.incomplete {
    background: #fffbeb;
    color: #92400e;
}

.save-status {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.save-status.saved {
    color: var(--success-color);
}

.save-status.saving {
    color: var(--warning-color);
}

.timesheet-grid {
    margin-top: 1.5rem;
    overflow-x: auto;
}

.timesheet-table {
    width: 100%;
    font-size: 0.875rem;
}

.timesheet-table th {
    position: sticky;
    top: 0;
    background: var(--bg-color);
    z-index: 10;
}

.day-cell {
    min-width: 80px;
}

.day-header {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.day-number {
    font-size: 1.125rem;
    font-weight: 700;
}

.day-name {
    font-size: 0.75rem;
    color: var(--text-secondary);
}

.weekend {
    background: #f1f5f9;
}

.holiday {
    background: #fef3c7;
}

.entry-cell {
    padding: 0.25rem;
}

.entry-select {
    width: 100%;
    padding: 0.375rem;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    font-size: 0.875rem;
    background: white;
}

.entry-select:focus {
    outline: none;
    border-color: var(--primary-color);
}

/* ===== BULK ACTIONS ===== */
.bulk-actions-panel {
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1.5rem;
    margin-bottom: 1.5rem;
}

.bulk-actions-title {
    font-weight: 600;
    margin-bottom: 1rem;
}

.bulk-actions-form {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
}

/* ===== MODAL ===== */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    padding: 1rem;
}

.modal {
    background: var(--surface-color);
    border-radius: 12px;
    width: 100%;
    max-width: 600px;
    max-height: 90vh;
    overflow-y: auto;
    box-shadow: var(--shadow-lg);
}

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

.modal-title {
    font-size: 1.25rem;
    font-weight: 600;
}

.modal-close {
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-secondary);
    padding: 0.25rem;
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 4px;
}

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

.modal-body {
    padding: 1.5rem;
}

.modal-footer {
    padding: 1.5rem;
    border-top: 1px solid var(--border-color);
    display: flex;
    justify-content: flex-end;
    gap: 0.75rem;
}

/* ===== TABS ===== */
.tabs {
    display: flex;
    border-bottom: 2px solid var(--border-color);
    margin-bottom: 1.5rem;
    gap: 0.5rem;
}

.tab {
    padding: 0.75rem 1.5rem;
    border: none;
    background: none;
    cursor: pointer;
    color: var(--text-secondary);
    font-weight: 500;
    border-bottom: 2px solid transparent;
    margin-bottom: -2px;
    transition: all 0.2s;
}

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

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

/* ===== CHARTS ===== */
.chart-container {
    padding: 1.5rem;
    background: var(--surface-color);
    border-radius: 8px;
    margin-bottom: 1.5rem;
}

.chart-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
}

/* ===== STATS CARDS ===== */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    margin-bottom: 2rem;
}

.stat-card {
    background: var(--surface-color);
    padding: 1.5rem;
    border-radius: 8px;
    box-shadow: var(--shadow);
}

.stat-label {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.stat-value {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary-color);
}

/* ===== LOADING ===== */
.loading {
    text-align: center;
    padding: 3rem;
    color: var(--text-secondary);
}

.spinner {
    width: 40px;
    height: 40px;
    border: 4px solid var(--border-color);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
    margin: 0 auto 1rem;
}

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

/* ===== RESPONSIVE ===== */
@media (max-width: 768px) {
    .main-content {
        padding: 1rem;
    }

    .header-content {
        flex-wrap: wrap;
        height: auto;
        padding: 1rem 0;
    }

    .nav-menu {
        width: 100%;
        justify-content: space-around;
    }

    .nav-item {
        padding: 0.5rem;
        font-size: 0.875rem;
    }

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

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

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

/* ===== UTILITIES ===== */
.hidden {
    display: none !important;
}

.text-center {
    text-align: center;
}

.text-right {
    text-align: right;
}

.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }

.flex { display: flex; }
.flex-center { display: flex; align-items: center; justify-content: center; }
.flex-between { display: flex; align-items: center; justify-content: space-between; }
.gap-1 { gap: 0.5rem; }
.gap-2 { gap: 1rem; }