* { box-sizing: border-box; margin: 0; padding: 0; font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif; }
body { background-color: #f4f7f6; color: #333; }
.container { max-width: 1000px; margin: 20px auto; padding: 20px; background: #fff; border-radius: 8px; box-shadow: 0 0 10px rgba(0,0,0,0.1); }
.error { color: red; margin-bottom: 15px; font-size: 0.9em; }

/* Login Page Styles */
.login-bg { display: flex; justify-content: center; align-items: center; height: 100vh; background-color: #e9ecef; }
.login-container { background: white; padding: 30px; border-radius: 8px; box-shadow: 0 4px 8px rgba(0,0,0,0.1); width: 100%; max-width: 400px; }
.input-group { margin-bottom: 15px; }
.input-group label { display: block; margin-bottom: 5px; }
.input-group input { width: 100%; padding: 10px; border: 1px solid #ccc; border-radius: 4px; }
.btn { width: 100%; padding: 10px; background-color: #007bff; color: white; border: none; border-radius: 4px; cursor: pointer; }
.btn:hover { background-color: #0056b3; }

/* Navbar Styles */
.navbar { background-color: #343a40; padding: 15px 20px; display: flex; justify-content: space-between; align-items: center; color: white; }
.logo { font-size: 1.2em; font-weight: bold; }
.nav-links { list-style: none; display: flex; gap: 20px; }
.nav-links li a { color: white; text-decoration: none; padding: 5px 10px; border-radius: 4px; }
.nav-links li a:hover { background-color: #495057; }
.logout-btn { color: #ff6b6b !important; }

/* Styles สำหรับ ฟอร์ม และ ตาราง */
.form-panel { background: #fafafa; padding: 20px; border-radius: 8px; border: 1px solid #ddd; margin-bottom: 20px; }
.form-panel h3 { margin-bottom: 15px; color: #007bff; }
.data-table { width: 100%; border-collapse: collapse; margin-top: 15px; }
.data-table th, .data-table td { padding: 12px; border: 1px solid #ddd; text-align: left; }
.data-table th { background-color: #343a40; color: white; }
.data-table tr:nth-child(even) { background-color: #f2f2f2; }
.data-table tr:hover { background-color: #e9ecef; }