:root {
    --bg-body: #e2e8f0;
    --bg-panel: #ffffff;
    --text-main: #0f172a;
    --text-muted: #64748b;
    --border-color: #cbd5e1;
    --brand-blue: #0284c7;
    --brand-blue-light: #e0f2fe;
    --status-ok: #059669;
    --status-warn: #d97706;
    --status-crit: #dc2626;
}

* { box-sizing: border-box; }
body {
    margin: 0;
    padding: 0;
    background-color: var(--bg-body);
    color: var(--text-main);
    font-family: 'Segoe UI', system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
    height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Top Navbar */
.navbar {
    background: var(--bg-panel);
    padding: 10px 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 2px solid var(--border-color);
    box-shadow: 0 2px 4px rgba(0,0,0,0.05);
    z-index: 10;
}
.nav-brand { font-size: 1.2em; font-weight: bold; color: var(--brand-blue); }
.nav-controls { display: flex; gap: 15px; align-items: center; }
.badge {
    padding: 5px 10px;
    border-radius: 4px;
    font-size: 0.8em;
    font-weight: bold;
    border: 1px solid currentColor;
}
.badge.auth { color: var(--brand-blue); background: var(--brand-blue-light); }
.badge.ok { color: var(--status-ok); background: #ecfdf5; border-color: var(--status-ok); }
.badge.warn { color: var(--status-warn); background: #fffbeb; border-color: var(--status-warn); }
.badge.crit { color: var(--status-crit); background: #fef2f2; border-color: var(--status-crit); }

/* Alert Banner */
.alert-banner {
    display: none;
    background: var(--status-crit);
    color: white;
    padding: 10px 20px;
    font-weight: bold;
    text-align: center;
    animation: pulse 2s infinite;
}
.alert-banner.active { display: block; }
@keyframes pulse { 0% { opacity: 1; } 50% { opacity: 0.85; } 100% { opacity: 1; } }

/* Tabs */
.tabs {
    display: flex;
    background: var(--bg-panel);
    border-bottom: 1px solid var(--border-color);
    padding: 0 20px;
}
.tab {
    padding: 15px 25px;
    cursor: pointer;
    font-weight: bold;
    color: var(--text-muted);
    border-bottom: 3px solid transparent;
    text-decoration: none;
}
.tab.active { color: var(--brand-blue); border-bottom-color: var(--brand-blue); }
.tab:hover:not(.active) { color: var(--text-main); }

/* Main Content Area */
.content {
    padding: 20px;
    flex: 1;
    overflow-y: auto;
}

/* Panels */
.panel {
    background: var(--bg-panel);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: 15px;
    box-shadow: 0 1px 3px rgba(0,0,0,0.05);
}
.panel h3 {
    margin: 0 0 10px 0;
    font-size: 0.85em;
    color: var(--text-muted);
    text-transform: uppercase;
}

/* Grid Layouts */
.grid-live {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 15px;
    margin-bottom: 15px;
}
.metric-val { font-size: 2em; font-weight: bold; font-family: monospace; }
.metric-unit { font-size: 0.5em; color: var(--text-muted); }

/* Toolbar */
.toolbar {
    display: flex;
    flex-wrap: wrap;
    gap: 15px;
    align-items: flex-end;
    margin-bottom: 20px;
    background: var(--bg-panel);
    padding: 15px;
    border-radius: 6px;
    border: 1px solid var(--border-color);
}
.input-group { display: flex; flex-direction: column; gap: 5px; }
.input-group label { font-size: 0.8em; font-weight: bold; color: var(--text-muted); }
.input-group input {
    padding: 8px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    font-family: inherit;
    color: var(--text-main);
    background: #fff;
}

button, .btn {
    display: inline-block;
    padding: 9px 15px;
    background: var(--brand-blue);
    color: white;
    border: none;
    border-radius: 4px;
    font-weight: bold;
    cursor: pointer;
    transition: opacity 0.2s;
    text-decoration: none;
}
button:hover, .btn:hover { opacity: 0.9; }
button.btn-export, .btn-export { background: #334155; }
button.btn-warn, .btn-warn { background: var(--status-warn); }
button:disabled { opacity: 0.5; cursor: not-allowed; }

/* Chart Containers */
.chart-box {
    position: relative;
    height: 400px;
    width: 100%;
}
.chart-box.tall { height: 500px; }

/* Graceful Fallback Overlay */
.fallback-overlay {
    display: none;
    position: absolute;
    top: 0; left: 0; right: 0; bottom: 0;
    background: rgba(255, 255, 255, 0.95);
    z-index: 10;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    border: 2px dashed var(--border-color);
    border-radius: 6px;
}
.fallback-overlay.active { display: flex; }
.fallback-icon { font-size: 3em; color: var(--text-muted); margin-bottom: 10px; }

/* Login */
.login-wrapper {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    background: var(--bg-body);
}
.login-card {
    background: var(--bg-panel);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    width: 360px;
    padding: 32px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
}
.login-card .nav-brand { font-size: 1.4em; margin-bottom: 8px; }
.login-subtitle { color: var(--text-muted); margin-bottom: 24px; font-size: 0.9em; }
.field { margin-bottom: 18px; }
.field label { display: block; font-size: 0.85em; font-weight: bold; color: var(--text-muted); margin-bottom: 6px; }
.field input {
    width: 100%; padding: 10px; border-radius: 4px;
    border: 1px solid var(--border-color); background: #fff; color: var(--text-main); font-size: 14px;
}
.field input:focus { outline: none; border-color: var(--brand-blue); }
.alert-error { color: var(--status-crit); margin-bottom: 14px; font-size: 0.9em; }
.login-hint { margin-top: 18px; text-align: center; font-size: 0.8em; color: var(--text-muted); }

/* Status colors */
.ok { color: var(--status-ok); }
.warn { color: var(--status-warn); }
.crit { color: var(--status-crit); }

@media (max-width: 768px) {
    .grid-live { grid-template-columns: repeat(2, 1fr); }
    .toolbar { flex-direction: column; align-items: stretch; }
    .nav-controls { gap: 8px; }
}