:root { --primary: #2563eb; --bg: #f8fafc; --card: #ffffff; --border: #e2e8f0; --text: #1e293b; --danger: #ef4444; }
* { box-sizing: border-box; margin: 0; padding: 0; }
body { background: var(--bg); font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif; color: var(--text); padding: 0; overflow-x: hidden; }
.container { max-width: 1000px; margin: auto; padding: 15px; }
nav { background: var(--primary); color: #fff; padding: 0.8rem 1.2rem; display: flex; justify-content: space-between; align-items: center; position: sticky; top: 0; z-index: 1000; box-shadow: 0 2px 4px rgba(0,0,0,0.1); }
.nav-brand { font-weight: bold; font-size: 1.2rem; z-index: 1001; }
.nav-menu-btn { display: none; background: none; border: none; color: white; font-size: 1.4rem; cursor: pointer; }
.nav-links { display: flex; gap: 15px; }
.nav-links a { color: #fff; text-decoration: none; font-size: 0.9rem; font-weight: 500; padding: 5px 10px; border-radius: 4px; transition: background 0.2s; }
.nav-links a:hover { background: rgba(255,255,255,0.15); }
.card { background: var(--card); padding: 20px; border-radius: 12px; border: 1px solid var(--border); margin-bottom: 20px; box-shadow: 0 4px 6px -1px rgba(0,0,0,0.1); }
.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 12px; }
input, select, button { width: 100%; padding: 12px; border: 1px solid var(--border); border-radius: 8px; margin-top: 6px; font-size: 1rem; outline: none; }
button { background: var(--primary); color: #fff; border: none; cursor: pointer; font-weight: 600; margin-top: 10px; display: inline-flex; align-items: center; justify-content: center; gap: 8px; }
.alert { padding: 15px; border-radius: 8px; margin-bottom: 20px; text-align: center; }
.alert.error { background: #fee2e2; color: #991b1b; border: 1px solid #fecaca; }
.table-responsive { overflow-x: auto; margin-top: 15px; border-radius: 8px; border: 1px solid var(--border); }
table { width: 100%; border-collapse: collapse; min-width: 600px; }
th, td { padding: 12px 15px; border-bottom: 1px solid var(--border); text-align: left; }
th { background: #f8fafc; font-weight: 600; cursor: pointer; color: #64748b; }

@media (max-width: 768px) {
    .nav-menu-btn { display: flex;  justify-content: end; }
    .nav-links { position: fixed; top: 0; right: -100%; height: 100vh; width: 250px; background: var(--primary); flex-direction: column; padding: 70px 20px; transition: 0.3s ease; box-shadow: -5px 0 15px rgba(0,0,0,0.2); }
    .nav-links.active { right: 0; }
    .grid { grid-template-columns: 1fr; }
}