:root {
  --primary-bg: #0f172a;
  --secondary-bg: #1e293b;
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --accent-color: #3b82f6;
  --border-color: #334155;
  --glass-bg: rgba(30, 41, 59, 0.7);
  --glass-border: rgba(255, 255, 255, 0.1);
}

body.theme-light-edu {
  --primary-bg: #f3f4f6;
  --secondary-bg: #ffffff;
  --text-main: #1f2937;
  --text-muted: #6b7280;
  --accent-color: #2563eb;
  --border-color: #e5e7eb;
  --glass-bg: rgba(255, 255, 255, 0.7);
  --glass-border: rgba(0, 0, 0, 0.1);
}

body.theme-green-edu {
  --primary-bg: #064e3b;
  --secondary-bg: #065f46;
  --text-main: #f8fafc;
  --text-muted: #a7f3d0;
  --accent-color: #10b981;
  --border-color: #047857;
  --glass-bg: rgba(6, 95, 70, 0.7);
  --glass-border: rgba(255, 255, 255, 0.1);
}

body.theme-maroon-edu {
  --primary-bg: #4a0404;
  --secondary-bg: #7f1d1d;
  --text-main: #f8fafc;
  --text-muted: #fca5a5;
  --accent-color: #dc2626;
  --border-color: #991b1b;
  --glass-bg: rgba(127, 29, 29, 0.7);
  --glass-border: rgba(255, 255, 255, 0.1);
}

* { box-sizing: border-box; margin: 0; padding: 0; }
body { font-family: 'Inter', sans-serif; background: var(--primary-bg); color: var(--text-main); }
a { text-decoration: none; color: inherit; }

.glass { background: var(--glass-bg); backdrop-filter: blur(10px); border: 1px solid var(--glass-border); }
.glass-card { background: var(--secondary-bg); border-radius: 12px; padding: 20px; border: 1px solid var(--glass-border); }

.btn { padding: 10px 16px; border-radius: 8px; border: none; cursor: pointer; font-weight: 500; }
.btn-primary { background: var(--accent-color); color: white; }
.btn-secondary { background: transparent; border: 1px solid var(--border-color); color: var(--text-main); }

.input-field { width: 100%; padding: 10px; border-radius: 8px; border: 1px solid var(--border-color); background: var(--primary-bg); color: var(--text-main); margin-top: 5px; }

.app-container { display: flex; min-height: 100vh; }
.sidebar { width: 250px; position: fixed; height: 100vh; display: flex; flex-direction: column; padding: 20px; }
.logo h2 { color: var(--accent-color); display: inline-block; }
.badge { background: var(--accent-color); font-size: 10px; padding: 2px 6px; border-radius: 4px; margin-left: 10px; }

.nav { margin-top: 30px; display: flex; flex-direction: column; gap: 20px; }
.section-title { font-size: 12px; color: var(--text-muted); text-transform: uppercase; margin-bottom: 8px; }
.nav-link { display: block; padding: 10px; border-radius: 8px; transition: 0.2s; }
.nav-link:hover, .nav-link.active { background: var(--secondary-bg); color: var(--accent-color); }

.main-content { margin-left: 250px; flex: 1; display: flex; flex-direction: column; }
.header { padding: 20px; border-bottom: 1px solid var(--border-color); }
.page-wrapper { padding: 30px; }

.view { display: none; }
.view.active { display: block; }

.stats-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 20px; margin-bottom: 30px; }

.table-container { border-radius: 12px; overflow: hidden; }
.data-table { width: 100%; border-collapse: collapse; text-align: left; }
.data-table th, .data-table td { padding: 15px; border-bottom: 1px solid var(--border-color); }
.data-table th { background: var(--secondary-bg); font-size: 13px; text-transform: uppercase; color: var(--text-muted); }

.header-actions { display: flex; justify-content: space-between; align-items: center; margin-bottom: 20px; }

.modal-overlay { position: fixed; top: 0; left: 0; width: 100%; height: 100%; background: rgba(0,0,0,0.7); display: flex; justify-content: center; align-items: center; z-index: 1000; }
.modal-overlay.hidden { display: none; }
.modal { width: 400px; }
.form-group { margin-bottom: 15px; }
.modal-actions { display: flex; justify-content: flex-end; gap: 10px; margin-top: 20px; }