:root {
    --primary: #2563eb; --secondary: #1e40af; --bg: #f3f4f6;
    --text: #1f2937; --white: #ffffff; --danger: #ef4444; --success: #10b981;
}
* { box-sizing: border-box; margin: 0; padding: 0; font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif; }
body { background-color: var(--bg); color: var(--text); display: flex; min-height: 100vh; }

/* Login Style */
.login-container { width: 100%; display: flex; justify-content: center; align-items: center; background: linear-gradient(135deg, var(--primary), var(--secondary)); }
.login-box { background: var(--white); padding: 2rem; border-radius: 1rem; box-shadow: 0 10px 25px rgba(0,0,0,0.2); width: 350px; text-align: center; }
.login-box h2 { margin-bottom: 1.5rem; color: var(--secondary); }
.form-group { margin-bottom: 1rem; text-align: left; }
.form-control { width: 100%; padding: 0.75rem; border: 1px solid #ddd; border-radius: 0.5rem; outline: none; transition: 0.3s; }
.form-control:focus { border-color: var(--primary); box-shadow: 0 0 0 3px rgba(37,99,235,0.2); }
.btn { width: 100%; padding: 0.75rem; border: none; border-radius: 0.5rem; background: var(--primary); color: white; font-weight: bold; cursor: pointer; transition: 0.3s; }
.btn:hover { background: var(--secondary); }

/* Dashboard Layout */
.sidebar { width: 250px; background: var(--white); height: 100vh; position: fixed; box-shadow: 2px 0 10px rgba(0,0,0,0.05); }
.sidebar-header { padding: 1.5rem; background: var(--primary); color: white; text-align: center; }
.menu { padding: 1rem; }
.menu a { display: block; padding: 1rem; color: var(--text); text-decoration: none; border-radius: 0.5rem; margin-bottom: 0.5rem; transition: 0.3s; }
.menu a:hover, .menu a.active { background: #e0e7ff; color: var(--primary); font-weight: bold; }
.main-content { margin-left: 250px; padding: 2rem; width: 100%; }

/* Cards & Tables */
.card { background: var(--white); padding: 1.5rem; border-radius: 1rem; box-shadow: 0 4px 6px rgba(0,0,0,0.05); margin-bottom: 2rem; }
table { width: 100%; border-collapse: collapse; margin-top: 1rem; }
th, td { padding: 1rem; text-align: left; border-bottom: 1px solid #eee; }
th { background: #f9fafb; color: var(--secondary); font-weight: 600; }
.badge { padding: 0.25rem 0.75rem; border-radius: 1rem; font-size: 0.8rem; font-weight: bold; color: white; }
.bg-success { background: var(--success); } .bg-danger { background: var(--danger); }
.btn-sm { padding: 0.5rem 1rem; font-size: 0.8rem; width: auto; }