/* Design System - Clean & Modern */
:root {
    --color-primary: #2563eb;
    --color-primary-hover: #1d4ed8;
    --color-primary-light: #dbeafe;
    --color-success: #10b981;
    --color-success-light: #d1fae5;
    --color-danger: #ef4444;
    --color-danger-light: #fee2e2;
    --color-warning: #f59e0b;
    --color-warning-light: #fef3c7;
    --color-gray-50: #f9fafb;
    --color-gray-100: #f3f4f6;
    --color-gray-200: #e5e7eb;
    --color-gray-300: #d1d5db;
    --color-gray-400: #9ca3af;
    --color-gray-500: #6b7280;
    --color-gray-600: #4b5563;
    --color-gray-700: #374151;
    --color-gray-800: #1f2937;
    --color-gray-900: #111827;
    --color-white: #ffffff;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    font-size: 0.875rem;
    line-height: 1.5;
    color: var(--color-gray-900);
    background-color: var(--color-gray-50);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Layout */
.panel-layout {
    display: flex;
    min-height: 100vh;
    background-color: var(--color-gray-50);
}

.panel-sidebar {
    width: 260px;
    background-color: var(--color-white);
    border-right: 1px solid var(--color-gray-200);
    display: flex;
    flex-direction: column;
    position: sticky;
    top: 0;
    height: 100vh;
    overflow-y: auto;
}

.panel-sidebar-header {
    padding: var(--spacing-lg);
    border-bottom: 1px solid var(--color-gray-200);
}

.panel-sidebar-title {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--color-gray-900);
    text-decoration: none;
    display: block;
}

.panel-sidebar-nav {
    padding: var(--spacing-md);
    flex: 1;
}

.panel-sidebar-nav-item {
    display: block;
    padding: var(--spacing-sm) var(--spacing-md);
    color: var(--color-gray-700);
    text-decoration: none;
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-xs);
    transition: all 0.15s ease;
    font-weight: 500;
}

.panel-sidebar-nav-item:hover {
    background-color: var(--color-gray-100);
    color: var(--color-gray-900);
}

.panel-sidebar-nav-item.active {
    background-color: var(--color-primary-light);
    color: var(--color-primary);
}

.panel-sidebar-footer {
    padding: var(--spacing-md);
    border-top: 1px solid var(--color-gray-200);
}

.panel-main {
    flex: 1;
    padding: var(--spacing-xl);
    max-width: 1400px;
    width: 100%;
}

/* Typography */
h1 {
    font-size: 1.875rem;
    font-weight: 700;
    color: var(--color-gray-900);
    margin-bottom: var(--spacing-lg);
}

h2 {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--color-gray-900);
    margin-bottom: var(--spacing-md);
}

h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--color-gray-800);
    margin-bottom: var(--spacing-md);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.625rem 1rem;
    font-size: 0.875rem;
    font-weight: 500;
    border-radius: var(--radius-md);
    border: none;
    cursor: pointer;
    transition: all 0.15s ease;
    text-decoration: none;
    gap: var(--spacing-sm);
}

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

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

.btn-secondary {
    background-color: var(--color-white);
    color: var(--color-gray-700);
    border: 1px solid var(--color-gray-300);
}

.btn-secondary:hover {
    background-color: var(--color-gray-50);
}

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

.btn-danger:hover {
    background-color: #dc2626;
}

.btn-sm {
    padding: 0.375rem 0.75rem;
    font-size: 0.8125rem;
}

/* Cards */
.card {
    background-color: var(--color-white);
    border-radius: var(--radius-lg);
    border: 1px solid var(--color-gray-200);
    box-shadow: var(--shadow-sm);
    padding: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
}

.card-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: var(--spacing-lg);
    padding-bottom: var(--spacing-md);
    border-bottom: 1px solid var(--color-gray-200);
}

.card-title {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--color-gray-900);
}

/* Tables */
.table-container {
    overflow-x: auto;
    border-radius: var(--radius-lg);
    border: 1px solid var(--color-gray-200);
    background-color: var(--color-white);
}

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

.table thead {
    background-color: var(--color-gray-50);
}

.table th {
    padding: var(--spacing-md);
    text-align: left;
    font-weight: 600;
    color: var(--color-gray-700);
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    border-bottom: 1px solid var(--color-gray-200);
}

.table td {
    padding: var(--spacing-md);
    border-bottom: 1px solid var(--color-gray-100);
    color: var(--color-gray-700);
}

.table tbody tr:hover {
    background-color: var(--color-gray-50);
}

.table tbody tr:last-child td {
    border-bottom: none;
}

/* Forms */
.form-group {
    margin-bottom: var(--spacing-lg);
}

.form-label {
    display: block;
    font-weight: 500;
    color: var(--color-gray-700);
    margin-bottom: var(--spacing-sm);
    font-size: 0.875rem;
}

.form-input,
.form-select,
.form-textarea {
    width: 100%;
    padding: 0.625rem 0.75rem;
    font-size: 0.875rem;
    border: 1px solid var(--color-gray-300);
    border-radius: var(--radius-md);
    background-color: var(--color-white);
    color: var(--color-gray-900);
    transition: all 0.15s ease;
}

.form-input:focus,
.form-select:focus,
.form-textarea:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px var(--color-primary-light);
}

.form-input::placeholder {
    color: var(--color-gray-400);
}

.form-checkbox-group {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.form-checkbox {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.form-checkbox input[type="checkbox"] {
    width: 1rem;
    height: 1rem;
    cursor: pointer;
}

.form-checkbox label {
    cursor: pointer;
    color: var(--color-gray-700);
}

.form-radio-group {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.form-radio {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.form-radio input[type="radio"] {
    width: 1rem;
    height: 1rem;
    cursor: pointer;
}

.form-radio label {
    cursor: pointer;
    color: var(--color-gray-700);
}

.form-error {
    color: var(--color-danger);
    font-size: 0.8125rem;
    margin-top: var(--spacing-xs);
}

.form-help {
    color: var(--color-gray-500);
    font-size: 0.8125rem;
    margin-top: var(--spacing-xs);
}

/* Badges */
.badge {
    display: inline-flex;
    align-items: center;
    padding: 0.25rem 0.625rem;
    font-size: 0.75rem;
    font-weight: 500;
    border-radius: var(--radius-sm);
}

.badge-success {
    background-color: var(--color-success-light);
    color: #047857;
}

.badge-danger {
    background-color: var(--color-danger-light);
    color: #991b1b;
}

.badge-primary {
    background-color: var(--color-primary-light);
    color: #1e40af;
}

.badge-gray {
    background-color: var(--color-gray-200);
    color: var(--color-gray-700);
}

.badge-warning {
    background-color: var(--color-warning-light);
    color: #92400e;
}

/* Alerts/Flash Messages */
.alert {
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-md);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.alert-success {
    background-color: var(--color-success-light);
    color: #047857;
    border: 1px solid #6ee7b7;
}

.alert-error {
    background-color: var(--color-danger-light);
    color: #991b1b;
    border: 1px solid #fca5a5;
}

.alert-warning {
    background-color: var(--color-warning-light);
    color: #92400e;
    border: 1px solid #fcd34d;
}

/* Utilities */
.text-muted {
    color: var(--color-gray-500);
}

.text-sm {
    font-size: 0.8125rem;
}

.mt-0 { margin-top: 0; }
.mt-1 { margin-top: var(--spacing-sm); }
.mt-2 { margin-top: var(--spacing-md); }
.mt-3 { margin-top: var(--spacing-lg); }
.mt-4 { margin-top: var(--spacing-xl); }

.mb-0 { margin-bottom: 0; }
.mb-1 { margin-bottom: var(--spacing-sm); }
.mb-2 { margin-bottom: var(--spacing-md); }
.mb-3 { margin-bottom: var(--spacing-lg); }
.mb-4 { margin-bottom: var(--spacing-xl); }

.flex {
    display: flex;
}

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

.gap-2 {
    gap: var(--spacing-md);
}

.gap-3 {
    gap: var(--spacing-lg);
}

/* Login Page */
.login-container {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    padding: var(--spacing-lg);
}

.login-card {
    background-color: var(--color-white);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    padding: var(--spacing-2xl);
    width: 100%;
    max-width: 420px;
}

.login-title {
    text-align: center;
    margin-bottom: var(--spacing-xl);
    color: var(--color-gray-900);
}

/* Action buttons */
.action-buttons {
    display: flex;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
}

/* Empty state */
.empty-state {
    text-align: center;
    padding: var(--spacing-2xl);
    color: var(--color-gray-500);
}

.empty-state-icon {
    font-size: 3rem;
    margin-bottom: var(--spacing-md);
    opacity: 0.5;
}