:root {
    --bg-dark: #0f172a;
    --sidebar-bg: #1e293b;
    --card-bg: #1e293b;
    --text-main: #f8fafc;
    --text-muted: #94a3b8;
    --primary: #3b82f6;
    --primary-hover: #2563eb;
    --danger: #ef4444;
    --danger-hover: #dc2626;
    --success: #10b981;
    --border-color: #334155;
    --input-bg: #0f172a;
    --sidebar-width: 260px;
    --header-height: 60px;
}
* { box-sizing: border-box; margin: 0; padding: 0; font-family: 'Inter', sans-serif; }
body { background-color: var(--bg-dark); color: var(--text-main); font-size: 15px; }
a { text-decoration: none; color: var(--primary); }
h1, h2, h3, h4 { color: white; }

.btn { display: inline-flex; align-items: center; justify-content: center; padding: 0.5rem 1rem; border-radius: 0.375rem; font-weight: 500; cursor: pointer; border: none; transition: 0.2s; font-size: 0.875rem; gap: 0.5rem; }
.btn-primary { background-color: var(--primary); color: white; }
.btn-primary:hover { background-color: var(--primary-hover); }
.btn-danger { background-color: rgba(239, 68, 68, 0.1); color: var(--danger); border: 1px solid var(--danger); }
.btn-danger:hover { background-color: var(--danger); color: white; }
.btn-sm { padding: 0.25rem 0.5rem; font-size: 0.75rem; }

.form-group { margin-bottom: 1rem; }
.form-group label { display: block; margin-bottom: 0.5rem; color: var(--text-muted); font-size: 0.875rem; }
.form-control { width: 100%; padding: 0.625rem; background-color: var(--input-bg); border: 1px solid var(--border-color); color: var(--text-main); border-radius: 0.375rem; }
.form-control:focus { outline: none; border-color: var(--primary); }

.app-wrapper { display: flex; min-height: 100vh; }
.sidebar { width: var(--sidebar-width); background-color: var(--sidebar-bg); border-right: 1px solid var(--border-color); position: fixed; height: 100vh; overflow-y: auto; }
.sidebar-logo { height: var(--header-height); display: flex; align-items: center; padding: 0 1.5rem; font-weight: bold; font-size: 1.25rem; border-bottom: 1px solid var(--border-color); color: white; }
.sidebar-logo i { color: var(--primary); margin-right: 10px; }
.sidebar-menu { padding: 1rem 0; list-style: none; }
.sidebar-menu li a { display: flex; align-items: center; padding: 0.75rem 1.5rem; color: var(--text-muted); font-size: 0.9rem; transition: all 0.2s; }
.sidebar-menu li a:hover, .sidebar-menu li a.active { background-color: rgba(59, 130, 246, 0.1); color: var(--primary); border-right: 3px solid var(--primary); }
.sidebar-menu li a i { margin-right: 0.75rem; font-size: 1.1rem; width: 20px; text-align: center; }

.main-content { flex: 1; margin-left: var(--sidebar-width); display: flex; flex-direction: column; }
.header { height: var(--header-height); background-color: var(--card-bg); border-bottom: 1px solid var(--border-color); display: flex; align-items: center; justify-content: space-between; padding: 0 2rem; }
.content-body { padding: 2rem; }

.page-title { margin-bottom: 1.5rem; font-size: 1.5rem; font-weight: 600; }

.card { background-color: var(--card-bg); border-radius: 0.5rem; border: 1px solid var(--border-color); padding: 1.5rem; margin-bottom: 1.5rem; box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1); }
.card-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 1.5rem; padding-bottom: 1rem; border-bottom: 1px solid var(--border-color); }
.card-title { font-size: 1.125rem; font-weight: 600; }

table { width: 100%; border-collapse: collapse; }
table th, table td { padding: 1rem; text-align: left; border-bottom: 1px solid var(--border-color); }
table th { color: var(--text-muted); font-weight: 500; font-size: 0.875rem; text-transform: uppercase; letter-spacing: 0.05em; }
table tr:hover td { background-color: rgba(255, 255, 255, 0.02); }

.badge { padding: 0.25rem 0.5rem; border-radius: 9999px; font-size: 0.75rem; font-weight: 500; }
.badge-success { background: rgba(16, 185, 129, 0.1); color: var(--success); border: 1px solid var(--success); }
.badge-danger { background: rgba(239, 68, 68, 0.1); color: var(--danger); border: 1px solid var(--danger); }

.flash-msg { padding: 1rem; border-radius: 0.375rem; margin-bottom: 1.5rem; }
.flash-success { background: rgba(16, 185, 129, 0.1); border: 1px solid var(--success); color: var(--success); }
.flash-error { background: rgba(239, 68, 68, 0.1); border: 1px solid var(--danger); color: var(--danger); }
.flash-warning { background: rgba(245, 158, 11, 0.1); border: 1px solid #f59e0b; color: #f59e0b; }

.auth-wrapper { display: flex; align-items: center; justify-content: center; min-height: 100vh; background-color: var(--bg-dark); }
.auth-box { width: 100%; max-width: 400px; }

.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.5rem; }
.stat-card { display: flex; align-items: center; padding: 1.5rem; }
.stat-icon { width: 48px; height: 48px; border-radius: 0.5rem; display: flex; align-items: center; justify-content: center; font-size: 1.5rem; background: rgba(59, 130, 246, 0.1); color: var(--primary); margin-right: 1rem; }
.stat-info h3 { font-size: 1.5rem; margin: 0; }
.stat-info p { color: var(--text-muted); margin: 0; font-size: 0.875rem; }

/* Hide mobile button on PC */
.mobile-menu-btn {
    display: none;
}

/* Mobile Responsiveness - Max Width 768px */
@media (max-width: 768px) {
    .sidebar {
        transform: translateX(-100%);
        transition: transform 0.3s ease;
        z-index: 1040;
    }
    .sidebar.open {
        transform: translateX(0);
    }
    
    #mobile-overlay {
        display: none;
        position: fixed;
        top: 0; left: 0; right: 0; bottom: 0;
        background: rgba(0, 0, 0, 0.5);
        z-index: 1030;
    }
    #mobile-overlay.active {
        display: block;
    }

    .main-content {
        margin-left: 0;
    }

    .header {
        padding: 0 1rem;
        gap: 10px;
    }
    
    .mobile-menu-btn {
        display: block;
        background: transparent;
        border: none;
        color: var(--text-main);
        font-size: 1.5rem;
        cursor: pointer;
        padding: 0;
        margin-right: 10px;
    }
    /* Tables scroll horizontally natively via bootstrap's .table-responsive, but force it if missing */
    .table-responsive {
        width: 100%;
        overflow-x: auto;
        -webkit-overflow-scrolling: touch;
    }

    .header-search {
        flex: 1;
        display: flex;
        justify-content: flex-start;
    }
    #masterServerDropdownContainer {
        width: 100%;
    }
    #masterServerDropdownContainer button {
        width: 100%;
        font-size: 0.85rem;
        padding: 6px 10px;
    }
    #masterServerDropdownWrap {
        width: 100% !important;
        max-width: 100%;
    }

    .header-user .user-name-text {
        display: none;
    }
    
    .header-user {
        gap: 8px !important;
    }

    .content-body {
        padding: 1rem;
    }

    .grid-3, .grid-4 {
        grid-template-columns: 1fr !important;
    }
    
    .page-title {
        font-size: 1.25rem;
    }
}