* { margin: 0; padding: 0; box-sizing: border-box; }
:root { --primary: #2563eb; --danger: #ef4444; --success: #10b981; --bg: #f8fafc; --card: #fff; --text: #1e293b; --border: #e2e8f0; }
body { font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif; background: var(--bg); color: var(--text); line-height: 1.6; }

.app-container { display: flex; min-height: 100vh; }
.sidebar { width: 260px; background: var(--card); border-right: 1px solid var(--border); position: fixed; height: 100vh; display: flex; flex-direction: column; }
.logo { padding: 20px; border-bottom: 1px solid var(--border); font-size: 20px; font-weight: 700; }
.nav-menu { flex: 1; padding: 20px 10px; }
.nav-link { display: flex; align-items: center; gap: 10px; padding: 12px 16px; color: #64748b; text-decoration: none; border-radius: 8px; margin-bottom: 4px; }
.nav-link:hover { background: var(--bg); }
.nav-link.active { background: var(--primary); color: white; }
.main-content { flex: 1; margin-left: 260px; padding: 30px; }

.page-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 30px; }
.page-title { font-size: 28px; font-weight: 700; }
.btn { padding: 10px 20px; border: none; border-radius: 8px; font-size: 14px; font-weight: 500; cursor: pointer; }
.btn-primary { background: var(--primary); color: white; }
.btn-secondary { background: white; border: 1px solid var(--border); }
.btn-sm { padding: 6px 12px; font-size: 13px; }

.stats-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); gap: 20px; margin-bottom: 30px; }
.stat-card { background: var(--card); padding: 24px; border-radius: 12px; border: 1px solid var(--border); }
.stat-value { font-size: 32px; font-weight: 700; margin: 10px 0; }

.card { background: var(--card); border-radius: 12px; border: 1px solid var(--border); padding: 24px; }
table { width: 100%; border-collapse: collapse; }
th { padding: 12px; text-align: left; background: var(--bg); }
td { padding: 16px; border-bottom: 1px solid var(--border); }

.form-group { margin-bottom: 20px; }
label { display: block; margin-bottom: 8px; }
input, select, textarea { width: 100%; padding: 10px; border: 1px solid var(--border); border-radius: 8px; }

.auth-screen { min-height: 100vh; display: flex; align-items: center; justify-content: center; background: linear-gradient(135deg, var(--primary), #1e40af); }
.auth-container { background: white; padding: 40px; border-radius: 12px; max-width: 440px; }