:root {
    --primary: #f5c518; /* vàng */
    --primary-dark: #d4a900;
    --secondary: #facc15;
    --success: #16a34a;
    --danger: #ef4444;
    --warning: #f97316;
    --bg: #f9fafb; /* nền trắng xám nhẹ */
    --sidebar-bg: #1e293b; /* xanh xám đậm */
    --text: #111827;
    --text-light: #6b7280;
    --border: #e5e7eb;
}

/* RESET */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: 'Inter', 'Segoe UI', Arial, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
}

/* LAYOUT */
.app-container {
    display: flex;
    min-height: 100vh;
}

/* SIDEBAR */
.sidebar {
    width: 250px;
    background: var(--sidebar-bg);
    color: white;
    padding: 24px 0;
    position: fixed;
    height: 100vh;
    overflow-y: auto;
}

.sidebar-header {
    padding: 0 24px 24px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    margin-bottom: 16px;
}

.brand {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 20px;
    font-weight: 700;
}

.brand-icon {
    width: 34px;
    height: 34px;
    background: var(--primary);
    color: black;
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.sidebar-nav {
    padding: 0 16px;
}

.nav-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 12px 16px;
    color: #cbd5e1;
    text-decoration: none;
    border-radius: 8px;
    margin-bottom: 6px;
    transition: all 0.25s;
}

    .nav-item:hover {
        background: rgba(255, 255, 255, 0.1);
        color: var(--primary);
        transform: translateX(3px);
    }

    .nav-item.active {
        background: var(--primary);
        color: black;
    }

/* MAIN CONTENT */
.main-content {
    flex: 1;
    margin-left: 250px;
    padding: 32px;
}

/* HEADER */
.top-header {
    background: white;
    padding: 16px 24px;
    border-radius: 12px;
    box-shadow: 0 1px 4px rgba(0, 0, 0, 0.05);
    margin-bottom: 24px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.page-title h1 {
    font-size: 24px;
    font-weight: 700;
    color: var(--text);
}

.page-title p {
    color: var(--text-light);
    font-size: 14px;
}

/* DASHBOARD CARDS */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 20px;
    margin-bottom: 24px;
}

.stat-card {
    background: white;
    padding: 20px;
    border-radius: 12px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.05);
    border-left: 5px solid var(--primary);
    transition: all 0.2s;
}

    .stat-card:hover {
        transform: translateY(-3px);
        box-shadow: 0 4px 8px rgba(0,0,0,0.08);
    }

/* CONTENT */
.content-card {
    background: white;
    border-radius: 12px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.05);
    margin-bottom: 24px;
    overflow: hidden;
}

.card-header {
    padding: 18px 24px;
    border-bottom: 1px solid var(--border);
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: #fff9db;
}

.card-title {
    font-size: 18px;
    font-weight: 600;
}

.card-body {
    padding: 24px;
}

/* BUTTONS */
.btn {
    padding: 10px 20px;
    border: none;
    border-radius: 8px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
}

.btn-primary {
    background: var(--primary);
    color: #111;
}

    .btn-primary:hover {
        background: var(--primary-dark);
    }

/* TABLE */
.data-table {
    width: 100%;
    border-collapse: collapse;
}

    .data-table th, .data-table td {
        padding: 12px 16px;
        border-bottom: 1px solid var(--border);
    }

    .data-table th {
        background: #f8fafc;
        text-align: left;
        color: var(--text-light);
        font-weight: 600;
    }

/* RESPONSIVE */
@media (max-width: 768px) {
    .sidebar {
        position: absolute;
        transform: translateX(-100%);
    }

    .main-content {
        margin-left: 0;
        padding: 16px;
    }
}