:root {
    --brand: #0a3b63;
    --brand-dark: #072d4d;
    --brand-light: #0f4f82;
    --bg: #f4f6f8;
    --surface: #ffffff;
    --border: #e2e8f0;
    --text: #1e293b;
    --text-muted: #64748b;
    --success: #15803d;
    --warning: #b45309;
    --danger: #b91c1c;
    --info: #0369a1;
    --sidebar-width: 240px;
    --topbar-height: 56px;
    --radius: 8px;
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.06);
}

*,
*::before,
*::after {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    font-size: 14px;
    line-height: 1.5;
    color: var(--text);
    background: var(--bg);
}

a {
    color: var(--brand-light);
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

/* Auth */
.auth-page {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 1rem;
    background: linear-gradient(160deg, var(--brand) 0%, var(--brand-dark) 100%);
}

.auth-card {
    width: 100%;
    max-width: 400px;
    background: var(--surface);
    padding: 2rem;
    border-radius: var(--radius);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.15);
}

.auth-card h1 {
    margin: 0 0 0.5rem;
    font-size: 1.35rem;
    color: var(--brand);
}

/* Layout */
.app-shell {
    display: flex;
    min-height: 100vh;
}

.sidebar {
    width: var(--sidebar-width);
    background: var(--brand);
    color: #fff;
    flex-shrink: 0;
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    z-index: 100;
    overflow-y: auto;
    transition: transform 0.2s ease;
}

.sidebar-brand {
    padding: 1.25rem 1rem;
    font-weight: 600;
    font-size: 1rem;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.sidebar-nav {
    list-style: none;
    margin: 0;
    padding: 0.75rem 0;
}

.sidebar-nav a {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.65rem 1rem;
    color: rgba(255, 255, 255, 0.85);
    text-decoration: none;
    border-left: 3px solid transparent;
}

.sidebar-nav a:hover,
.sidebar-nav a.active {
    background: rgba(255, 255, 255, 0.08);
    color: #fff;
    text-decoration: none;
}

.sidebar-nav a.active {
    border-left-color: #fff;
    font-weight: 500;
}

.main-wrap {
    flex: 1;
    margin-left: var(--sidebar-width);
    min-width: 0;
}

.topbar {
    height: var(--topbar-height);
    background: var(--surface);
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 1.5rem;
    position: sticky;
    top: 0;
    z-index: 50;
}

.topbar-title {
    font-weight: 600;
    font-size: 1.05rem;
    color: var(--brand);
}

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

.menu-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 1.25rem;
    cursor: pointer;
    color: var(--brand);
    padding: 0.25rem;
}

.content {
    padding: 1.5rem;
}

/* Cards & stats */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.stat-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.25rem;
    box-shadow: var(--shadow);
}

.stat-card .label {
    font-size: 0.8rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.03em;
}

.stat-card .value {
    font-size: 1.75rem;
    font-weight: 600;
    color: var(--brand);
    margin-top: 0.25rem;
}

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

.card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    margin-bottom: 1.5rem;
}

.card-header {
    padding: 1rem 1.25rem;
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 0.75rem;
}

.card-header h2 {
    margin: 0;
    font-size: 1rem;
    font-weight: 600;
    color: var(--brand);
}

.card-body {
    padding: 1.25rem;
}

.grid-2 {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 1.5rem;
}

/* Alerts panel */
.alerts-panel {
    margin-bottom: 1.5rem;
}

.alert-item {
    padding: 0.65rem 1rem;
    border-left: 4px solid var(--info);
    background: #eff6ff;
    margin-bottom: 0.5rem;
    border-radius: 0 var(--radius) var(--radius) 0;
    font-size: 0.9rem;
}

.alert-item.warning {
    border-left-color: var(--warning);
    background: #fffbeb;
}

.alert-item.danger {
    border-left-color: var(--danger);
    background: #fef2f2;
}

/* Tables */
.table-wrap {
    overflow-x: auto;
}

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

table.data-table th,
table.data-table td {
    padding: 0.75rem 1rem;
    text-align: left;
    border-bottom: 1px solid var(--border);
}

table.data-table th {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    color: var(--text-muted);
    font-weight: 600;
    background: #f8fafc;
}

table.data-table tr:hover td {
    background: #fafbfc;
}

table.data-table .actions {
    white-space: nowrap;
}

/* Forms */
.form-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 1rem;
}

.form-group {
    margin-bottom: 1rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.35rem;
    font-weight: 500;
    font-size: 0.85rem;
    color: var(--text);
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 0.5rem 0.75rem;
    border: 1px solid var(--border);
    border-radius: 6px;
    font-size: 14px;
    font-family: inherit;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--brand-light);
    box-shadow: 0 0 0 2px rgba(10, 59, 99, 0.12);
}

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

.form-full {
    grid-column: 1 / -1;
}

.filters-bar {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    align-items: flex-end;
    margin-bottom: 1rem;
}

.filters-bar .form-group {
    margin-bottom: 0;
    min-width: 160px;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.35rem;
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
    font-weight: 500;
    border-radius: 6px;
    border: 1px solid transparent;
    cursor: pointer;
    font-family: inherit;
    text-decoration: none;
    line-height: 1.4;
}

.btn:hover {
    text-decoration: none;
}

.btn-primary {
    background: var(--brand);
    color: #fff;
    border-color: var(--brand);
}

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

.btn-secondary {
    background: var(--surface);
    color: var(--text);
    border-color: var(--border);
}

.btn-secondary:hover {
    background: #f1f5f9;
}

.btn-danger {
    background: #fff;
    color: var(--danger);
    border-color: #fecaca;
}

.btn-danger:hover {
    background: #fef2f2;
}

.btn-sm {
    padding: 0.3rem 0.6rem;
    font-size: 0.8rem;
}

.btn-block {
    width: 100%;
}

.btn-group {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

/* Badges */
.badge {
    display: inline-block;
    padding: 0.2rem 0.5rem;
    font-size: 0.75rem;
    font-weight: 500;
    border-radius: 4px;
}

.badge-success { background: #dcfce7; color: var(--success); }
.badge-warning { background: #fef3c7; color: var(--warning); }
.badge-danger { background: #fee2e2; color: var(--danger); }
.badge-info { background: #e0f2fe; color: var(--info); }
.badge-muted { background: #f1f5f9; color: var(--text-muted); }

.status-aktif, .status-ödendi { color: var(--success); }
.status-pasif { color: var(--text-muted); }
.status-bekliyor, .status-beklemede { color: var(--warning); }
.status-gecikti { color: var(--danger); font-weight: 500; }

/* Messages */
.alert {
    padding: 0.75rem 1rem;
    border-radius: 6px;
    margin-bottom: 1rem;
}

.alert-success {
    background: #dcfce7;
    color: var(--success);
    border: 1px solid #bbf7d0;
}

.alert-error {
    background: #fee2e2;
    color: var(--danger);
    border: 1px solid #fecaca;
}

.text-muted {
    color: var(--text-muted);
}

.empty-state {
    text-align: center;
    padding: 2rem;
    color: var(--text-muted);
}

.modal-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.4);
    z-index: 200;
    align-items: center;
    justify-content: center;
    padding: 1rem;
}

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

.modal {
    background: var(--surface);
    border-radius: var(--radius);
    max-width: 640px;
    width: 100%;
    max-height: 90vh;
    overflow-y: auto;
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.2);
}

.modal-header {
    padding: 1rem 1.25rem;
    border-bottom: 1px solid var(--border);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.modal-header h3 {
    margin: 0;
    font-size: 1rem;
}

.modal-body {
    padding: 1.25rem;
}

.modal-footer {
    padding: 1rem 1.25rem;
    border-top: 1px solid var(--border);
    display: flex;
    justify-content: flex-end;
    gap: 0.5rem;
}

.sidebar-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.4);
    z-index: 90;
}

@media (max-width: 768px) {
    .sidebar {
        transform: translateX(-100%);
    }

    .sidebar.open {
        transform: translateX(0);
    }

    .sidebar-overlay.open {
        display: block;
    }

    .main-wrap {
        margin-left: 0;
    }

    .menu-toggle {
        display: block;
    }

    .content {
        padding: 1rem;
    }

    .topbar {
        padding: 0 1rem;
    }
}