* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: Arial, Helvetica, sans-serif;
}

body {
    display: flex;
    background-color: #f4f5f7;
    min-height: 100vh;
}

/* --- THANH MENU BÊN TRÁI --- */
.leftbar {
    width: 200px;
    background-color: #2c3e50;
    color: white;
    padding: 20px 0;
    display: flex;
    flex-direction: column;
}

.leftbar h2 {
    padding: 0 20px 20px 20px;
    font-size: 1.4em;
}

.leftbar a {
    color: #cbd5e1;
    text-decoration: none;
    padding: 10px 20px;
    font-size: 0.9em;
    display: block;
}

.leftbar a:hover {
    background-color: #34495e;
    color: white;
}

/* --- NỘI DUNG CHÍNH --- */
.main {
    flex: 1;
    padding: 30px 40px;
}

.main h1 {
    font-size: 1.6em;
    color: #1e293b;
    margin-bottom: 20px;
}

/* --- CÁC THẺ CARD --- */
.cards {
    display: flex;
    gap: 20px;
    margin-bottom: 30px;
}

.card {
    flex: 1;
    background-color: white;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.05);
}

.card h3 {
    font-size: 0.95em;
    color: #0f172a;
    margin-bottom: 8px;
}

.card p {
    font-size: 0.9em;
    color: #64748b;
}

/* --- BẢNG DỮ LIỆU --- */
.main h2#users {
    font-size: 1.2em;
    color: #1e293b;
    margin-bottom: 15px;
}

table {
    width: 100%;
    border-collapse: collapse;
    background-color: white;
}

th {
    background-color: #f1f5f9;
    color: #0f172a;
    text-align: left;
    padding: 12px 15px;
    font-size: 0.85em;
    font-weight: bold;
}

td {
    padding: 12px 15px;
    border-bottom: 1px solid #e2e8f0;
    font-size: 0.85em;
    color: #334155;
}

/* Căn chỉnh cột trong bảng */
th:first-child, td:first-child {
    width: 10%;
}