:root {
  /* Professional Corporate Palette */
  --bg-app: #f8fafc;       /* Slate 50 */
  --bg-card: #ffffff;      /* White */
  
  --text-main: #1e293b;    /* Slate 800 */
  --text-muted: #64748b;   /* Slate 500 */
  
  /* Enhanced Brand Colors with Gradients */
  --primary: #4f46e5;      /* Indigo */
  --primary-light: #818cf8; /* Light Indigo */
  --secondary: #0ea5e9;    /* Sky */
  --secondary-light: #38bdf8; /* Light Sky */
  --danger: #f43f5e;       /* Rose */
  --danger-light: #fb7185; /* Light Rose */
  --success: #10b981;      /* Emerald */
  --success-light: #34d399; /* Light Emerald */
  --warning: #f59e0b;      /* Amber */
  --warning-light: #fcd34d; /* Light Amber */
  --info: #8b5cf6;         /* Violet */
  --info-light: #a78bfa;   /* Light Violet */
  --header-bg: #0f172a;    /* Slate 900 */
  
  --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);

  /* Component Colors */
  --input-bg: #ffffff;
  --input-border: #cbd5e1;
  --panel-header-bg: #ffffff;
  --panel-border: #f1f5f9;
  --kpi-grad-start: #ffffff;
  --kpi-grad-end: #f8fafc;
  --chart-bg: #ffffff;
}

[data-theme="dark"] {
  --bg-app: #0f172a;       /* Slate 900 */
  --bg-card: #1e293b;      /* Slate 800 */
  --text-main: #f1f5f9;    /* Slate 100 */
  --text-muted: #94a3b8;   /* Slate 400 */
  --input-bg: #1e293b;
  --input-border: #334155;
  --panel-header-bg: #1e293b;
  --panel-border: #334155;
  --kpi-grad-start: #1e293b;
  --kpi-grad-end: #0f172a;
  --chart-bg: #1e293b;
  --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.5), 0 2px 4px -1px rgba(0, 0, 0, 0.3);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  padding: 0;
  font-family: 'Inter', sans-serif;
  background-color: var(--bg-app);
  color: var(--text-main);
  height: 100vh;
  display: flex;
  flex-direction: column;
}

/* --- Header Section --- */
.main-header {
  background: linear-gradient(to right, #0f172a, #1e293b);
  padding: 20px 40px;
  text-align: center;
  border-bottom: none;
  position: relative;
  flex-shrink: 0;
  box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
}

.main-header h1 {
  margin: 0;
  font-size: 2.2rem; /* Big Professional Font */
  font-weight: 800;
  color: #ffffff;
  letter-spacing: -0.02em;
  text-transform: uppercase;
}

.subtitle {
  margin: 8px 0 0;
  color: #94a3b8;
  font-size: 0.95rem;
  font-weight: 500;
}

.system-status {
  position: absolute;
  right: 40px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 0.85rem;
  color: var(--text-muted);
  background: var(--bg-app);
  padding: 8px 12px;
  border-radius: 20px;
  border: 1px solid var(--input-border);
}

.theme-toggle {
  position: absolute;
  left: 40px;
  top: 50%;
  transform: translateY(-50%);
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.2);
  color: white;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  transition: all 0.2s;
}

.theme-toggle:hover {
  background: rgba(255, 255, 255, 0.2);
}

/* --- Filter Panel --- */
.filter-panel {
  background: var(--bg-card);
  padding: 16px 24px;
  border-bottom: 1px solid #e2e8f0;
  display: flex;
  gap: 16px;
  align-items: center;
  flex-wrap: wrap;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
}

.filter-group {
  display: flex;
  align-items: center;
  gap: 8px;
}

.filter-group label {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--text-main);
  white-space: nowrap;
}

.filter-input {
  padding: 8px 12px;
  border: 1px solid var(--input-border);
  border-radius: 6px;
  font-size: 0.875rem;
  background: var(--input-bg);
  color: var(--text-main);
  cursor: pointer;
  transition: all 0.2s;
}

.filter-input:hover {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.filter-input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
}

.filter-reset {
  margin-left: auto;
  padding: 8px 16px;
  background: var(--danger);
  color: #ffffff;
  border: none;
  border-radius: 6px;
  font-size: 0.875rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
}

.filter-reset:hover {
  background: #dc2626;
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(239, 68, 68, 0.2);
}

/* --- Main Layout --- */
.grid-container {
  flex-grow: 1;
  padding: 24px;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  grid-template-rows: auto 1fr 1fr;
  gap: 24px;
  overflow: hidden;
}

/* --- KPI Cards --- */
.kpi-section {
  grid-column: 1 / -1;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  height: 110px;
}

.kpi-card {
  background: var(--bg-card);
  border-radius: 12px;
  box-shadow: var(--shadow);
  display: flex;
  align-items: center;
  padding: 0 24px;
  border-top: 4px solid transparent; /* Colored Accent Top */
  border-left: none;
  transition: transform 0.2s, box-shadow 0.2s;
}

.kpi-card:hover { 
  transform: translateY(-3px);
  box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.15);
}

/* Integration: Borders match Chart Colors */
.kpi-card.accent-blue { border-top-color: var(--primary); background: linear-gradient(180deg, var(--kpi-grad-start) 0%, var(--kpi-grad-end) 100%); }
.kpi-card.accent-cyan { border-top-color: var(--secondary); background: linear-gradient(180deg, var(--kpi-grad-start) 0%, var(--kpi-grad-end) 100%); }
.kpi-card.accent-red { border-top-color: var(--danger); background: linear-gradient(180deg, var(--kpi-grad-start) 0%, var(--kpi-grad-end) 100%); }
.kpi-card.accent-green { border-top-color: var(--success); background: linear-gradient(180deg, var(--kpi-grad-start) 0%, var(--kpi-grad-end) 100%); }

.kpi-icon { font-size: 2rem; margin-right: 20px; opacity: 0.8; }

.kpi-label { font-size: 0.75rem; font-weight: 700; text-transform: uppercase; color: var(--text-muted); letter-spacing: 0.05em; margin-bottom: 4px; }
.kpi-value { font-size: 1.8rem; font-weight: 800; color: var(--text-main); line-height: 1; }
.kpi-sub { font-size: 0.85rem; color: var(--text-muted); margin-top: 6px; }

/* --- Chart Panels --- */
.chart-panel {
  background: var(--bg-card);
  border-radius: 12px;
  box-shadow: var(--shadow);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  border: 1px solid #e2e8f0;
  transition: box-shadow 0.2s;
}

.chart-panel:hover {
  box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.1);
}

.chart-panel.span-2 { grid-column: span 2; }

/* Enhanced Chart Headings */
.panel-header {
  background: var(--panel-header-bg);
  padding: 16px 24px;
  border-bottom: 1px solid var(--panel-border);
}

.panel-header h2 {
  margin: 0;
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-main);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.chart-canvas {
  flex-grow: 1;
  width: 100%;
  position: relative;
  background-color: var(--chart-bg);
}

/* Mobile Responsive */
@media (max-width: 1200px) {
  .grid-container { display: block; overflow-y: auto; height: auto; }
  .kpi-section { grid-template-columns: 1fr 1fr; margin-bottom: 20px; height: auto; row-gap: 20px;}
  .chart-panel { height: 450px; margin-bottom: 24px; }
  .system-status { display: none; }
  .main-header h1 { font-size: 1.5rem; }
  .filter-panel { flex-direction: column; align-items: stretch; }
  .filter-group { width: 100%; }
  .filter-reset { margin-left: 0; }
}