:root {
    --bg-color: #0f172a;
    --bg-elevated: #1e293b;
    --bg-input: #0f172a;
    --border-color: #334155;
    --text-main: #ffffff;
    --text-muted: #94a3b8;
    --brand: #0e428a;
    --brand-hover: #154080;
    --accent-cyan: #0ea5e9;
    --success: #10b981;
    --error: #ef4444;
    --radius-sm: 8px;
    --radius-lg: 16px;
    --sidebar-width: 250px;
    --topbar-height: 64px;
}
* { box-sizing: border-box; font-family: 'Inter', sans-serif; }
body { margin: 0; background-color: var(--bg-color); color: var(--text-main); font-size: 14px; }

/* Login Ekranı Stilleri */
.login-body { display: flex; align-items: center; justify-content: center; min-height: 100vh; padding: 20px; }
.login-container { width: 100%; max-width: 420px; }
.card { background: var(--bg-elevated); border: 1px solid var(--border-color); border-radius: var(--radius-lg); overflow: hidden; }
.login-card { padding: 40px; position: relative; }
.login-card::before { content: ''; position: absolute; top: 0; left: 0; right: 0; height: 4px; background: linear-gradient(90deg, var(--brand), var(--accent-cyan)); }
.login-header { text-align: center; margin-bottom: 30px; }
.form-group { margin-bottom: 16px; }
.form-label { display: block; font-size: 12px; color: var(--text-muted); margin-bottom: 6px; }
.form-control { width: 100%; height: 44px; padding: 0 14px; background: var(--bg-input); border: 1px solid var(--border-color); border-radius: var(--radius-sm); color: var(--text-main); outline: none; }
.form-control:focus { border-color: var(--accent-cyan); }
.btn-primary { width: 100%; height: 48px; background: linear-gradient(135deg, var(--brand), var(--brand-hover)); border: none; border-radius: var(--radius-sm); color: #fff; font-weight: 600; cursor: pointer; }
.alert-danger { background: rgba(239, 68, 68, 0.1); border: 1px solid rgba(239, 68, 68, 0.2); color: var(--error); padding: 14px; border-radius: var(--radius-sm); margin-bottom: 16px; }

/* Admin Sidebar & Topbar */
.admin-sidebar { position: fixed; top: 0; left: 0; bottom: 0; width: var(--sidebar-width); background: var(--bg-elevated); border-right: 1px solid var(--border-color); }
.sidebar-brand { height: var(--topbar-height); display: flex; align-items: center; padding: 0 20px; border-bottom: 1px solid var(--border-color); font-weight: 700; font-size: 16px; color: var(--accent-cyan); }
.sidebar-nav { padding: 16px 12px; }
.sidebar-link { display: flex; align-items: center; gap: 12px; padding: 11px 12px; color: var(--text-muted); text-decoration: none; border-radius: var(--radius-sm); margin-bottom: 5px; }
.sidebar-link.active, .sidebar-link:hover { background: rgba(14, 165, 233, 0.1); color: var(--accent-cyan); }

.admin-topbar { position: fixed; top: 0; left: var(--sidebar-width); right: 0; height: var(--topbar-height); background: var(--bg-elevated); border-bottom: 1px solid var(--border-color); display: flex; align-items: center; justify-content: space-between; padding: 0 24px; }
.admin-content { margin-left: var(--sidebar-width); padding-top: var(--topbar-height); min-height: 100vh; }
.admin-content-inner { padding: 24px; max-width: 1200px; margin: 0 auto; }

/* Dashboard Metrik Kartları */
.stats-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 16px; margin-bottom: 24px; }
.stat-card { background: var(--bg-elevated); border: 1px solid var(--border-color); border-radius: var(--radius-lg); padding: 20px; }
.stat-label { font-size: 12px; color: var(--text-muted); text-transform: uppercase; margin-bottom: 8px; font-weight: 600; }
.stat-value { font-size: 24px; font-weight: 700; color: var(--success); }
.chart-card { background: var(--bg-elevated); border: 1px solid var(--border-color); border-radius: var(--radius-lg); padding: 20px; }
</style>