/* ============================================================
   NEXUS DASHBOARD — Premium Dark Theme
   ============================================================ */

:root {
  /* Surfaces */
  --bg-deep:       #0a0b14;
  --bg-base:       #0f1023;
  --bg-elevated:   #161832;
  --bg-card:       rgba(22, 24, 50, 0.65);
  --bg-card-hover: rgba(30, 33, 65, 0.75);

  /* Borders */
  --border-subtle: rgba(255, 255, 255, 0.06);
  --border-accent: rgba(139, 92, 246, 0.25);

  /* Text */
  --text-primary:   #f0f0f8;
  --text-secondary: #8b8da8;
  --text-muted:     #5a5c75;

  /* Accent Gradient */
  --accent-start: #8B5CF6;
  --accent-mid:   #6366F1;
  --accent-end:   #06B6D4;
  --gradient-accent: linear-gradient(135deg, var(--accent-start), var(--accent-mid), var(--accent-end));

  /* Status */
  --green:  #34D399;
  --red:    #F87171;
  --yellow: #FBBF24;
  --blue:   #60A5FA;

  /* Shadows */
  --shadow-card: 0 4px 24px rgba(0, 0, 0, 0.3), 0 1px 2px rgba(0, 0, 0, 0.2);
  --shadow-glow: 0 0 40px rgba(139, 92, 246, 0.15);

  /* Layout */
  --sidebar-w: 260px;
  --radius: 16px;
  --radius-sm: 10px;
  --radius-xs: 6px;
}

/* Reset */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { font-size: 14px; }

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  background: var(--bg-deep);
  color: var(--text-primary);
  overflow-x: hidden;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Ambient Background */
.ambient-glow {
  position: fixed;
  top: -200px;
  right: -200px;
  width: 700px;
  height: 700px;
  background: radial-gradient(circle, rgba(139, 92, 246, 0.12) 0%, rgba(6, 182, 212, 0.06) 40%, transparent 70%);
  pointer-events: none;
  z-index: 0;
  animation: ambientPulse 8s ease-in-out infinite alternate;
}

.noise-overlay {
  position: fixed;
  inset: 0;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noise'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noise)' opacity='0.03'/%3E%3C/svg%3E");
  pointer-events: none;
  z-index: 0;
  opacity: 0.5;
}

@keyframes ambientPulse {
  0%   { transform: scale(1) translate(0, 0); opacity: 1; }
  100% { transform: scale(1.15) translate(-30px, 20px); opacity: 0.7; }
}

/* ============================================================
   LAYOUT
   ============================================================ */
.app {
  display: flex;
  min-height: 100vh;
  position: relative;
  z-index: 1;
}

/* Sidebar */
.sidebar {
  width: var(--sidebar-w);
  background: rgba(15, 16, 35, 0.85);
  backdrop-filter: blur(20px);
  border-right: 1px solid var(--border-subtle);
  display: flex;
  flex-direction: column;
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  z-index: 100;
  padding: 24px 16px;
}

.sidebar-brand {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 0 8px 28px;
}

.brand-icon {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(139, 92, 246, 0.1);
  border-radius: 12px;
  border: 1px solid rgba(139, 92, 246, 0.2);
}

.brand-text {
  font-size: 1.35rem;
  font-weight: 700;
  background: var(--gradient-accent);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  letter-spacing: -0.02em;
}

.sidebar-nav {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.nav-section-label {
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  padding: 20px 12px 8px;
}

.nav-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.92rem;
  font-weight: 500;
  transition: all 0.2s ease;
  position: relative;
}

.nav-item:hover {
  color: var(--text-primary);
  background: rgba(255, 255, 255, 0.04);
}

.nav-item.active {
  color: var(--text-primary);
  background: rgba(139, 92, 246, 0.12);
}

.nav-item.active::before {
  content: '';
  position: absolute;
  left: -16px;
  top: 50%;
  transform: translateY(-50%);
  width: 3px;
  height: 24px;
  background: var(--gradient-accent);
  border-radius: 0 4px 4px 0;
}

.sidebar-footer {
  padding-top: 16px;
  border-top: 1px solid var(--border-subtle);
}

.user-card {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 8px;
}

.user-avatar {
  width: 36px;
  height: 36px;
  border-radius: 10px;
  background: linear-gradient(135deg, rgba(139, 92, 246, 0.3), rgba(6, 182, 212, 0.3));
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-secondary);
}

.user-info {
  display: flex;
  flex-direction: column;
}

.user-name {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-primary);
}

.user-role {
  font-size: 0.72rem;
  color: var(--text-muted);
}

/* Main */
.main {
  flex: 1;
  margin-left: var(--sidebar-w);
  padding: 28px 32px 40px;
  min-height: 100vh;
}

/* Topbar */
.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 28px;
  animation: fadeSlideDown 0.5s ease both;
}

.page-title {
  font-size: 1.7rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  background: var(--gradient-accent);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.page-subtitle {
  display: block;
  font-size: 0.88rem;
  color: var(--text-secondary);
  margin-top: 4px;
}

.topbar-right {
  display: flex;
  align-items: center;
  gap: 10px;
}

.search-box {
  display: flex;
  align-items: center;
  gap: 8px;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  padding: 8px 14px;
  backdrop-filter: blur(12px);
  transition: border-color 0.2s;
}

.search-box:focus-within {
  border-color: var(--border-accent);
  box-shadow: 0 0 0 3px rgba(139, 92, 246, 0.08);
}

.search-box svg { color: var(--text-muted); flex-shrink: 0; }

.search-box input {
  background: none;
  border: none;
  outline: none;
  color: var(--text-primary);
  font-size: 0.85rem;
  width: 200px;
  font-family: inherit;
}

.search-box input::placeholder { color: var(--text-muted); }

.icon-btn {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.2s;
  position: relative;
  backdrop-filter: blur(12px);
}

.icon-btn:hover {
  background: var(--bg-card-hover);
  color: var(--text-primary);
  border-color: var(--border-accent);
}

.notification-dot {
  position: absolute;
  top: 9px;
  right: 9px;
  width: 7px;
  height: 7px;
  background: var(--red);
  border-radius: 50%;
  border: 2px solid var(--bg-elevated);
}

/* ============================================================
   CONTENT GRID
   ============================================================ */
.content-grid {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 20px;
  animation: fadeSlideUp 0.6s ease both;
  animation-delay: 0.1s;
}

/* KPI Row */
.kpi-row {
  grid-column: 1 / -1;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

/* Cards */
.card {
  background: var(--bg-card);
  backdrop-filter: blur(16px);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: var(--shadow-card);
  transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease;
  position: relative;
  overflow: hidden;
}

.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(139, 92, 246, 0.3), rgba(6, 182, 212, 0.3), transparent);
  opacity: 0;
  transition: opacity 0.3s;
}

.card:hover::before { opacity: 1; }

.card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-card), var(--shadow-glow);
  border-color: var(--border-accent);
}

/* KPI Card */
.kpi-card {
  background: var(--bg-card);
  backdrop-filter: blur(16px);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius);
  padding: 22px;
  box-shadow: var(--shadow-card);
  transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease;
  position: relative;
  overflow: hidden;
  animation: fadeSlideUp 0.5s ease both;
}

.kpi-card[data-delay="0"] { animation-delay: 0.1s; }
.kpi-card[data-delay="1"] { animation-delay: 0.15s; }
.kpi-card[data-delay="2"] { animation-delay: 0.2s; }
.kpi-card[data-delay="3"] { animation-delay: 0.25s; }

.kpi-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(139, 92, 246, 0.4), transparent);
  opacity: 0;
  transition: opacity 0.3s;
}

.kpi-card:hover::before { opacity: 1; }

.kpi-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-card), var(--shadow-glow);
  border-color: var(--border-accent);
}

.kpi-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 14px;
}

.kpi-label {
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--text-secondary);
}

.kpi-icon {
  width: 36px;
  height: 36px;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.revenue-icon   { background: rgba(52, 211, 153, 0.12); color: var(--green); }
.users-icon     { background: rgba(96, 165, 250, 0.12); color: var(--blue); }
.conversion-icon { background: rgba(251, 191, 36, 0.12); color: var(--yellow); }
.session-icon   { background: rgba(139, 92, 246, 0.12); color: var(--accent-start); }

.kpi-value {
  font-size: 1.9rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  color: var(--text-primary);
  line-height: 1;
  margin-bottom: 12px;
  font-variant-numeric: tabular-nums;
}

.kpi-footer {
  display: flex;
  align-items: center;
  gap: 8px;
}

.kpi-trend {
  display: inline-flex;
  align-items: center;
  gap: 3px;
  font-size: 0.78rem;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: 20px;
}

.kpi-trend.up {
  color: var(--green);
  background: rgba(52, 211, 153, 0.1);
}

.kpi-trend.down {
  color: var(--red);
  background: rgba(248, 113, 113, 0.1);
}

.kpi-period {
  font-size: 0.75rem;
  color: var(--text-muted);
}

.sparkline {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 50px;
  pointer-events: none;
  opacity: 0.4;
}

/* Card Layouts */
.card-main-chart {
  grid-column: 1 / 3;
}

.card-donut {
  grid-column: 3 / 4;
  grid-row: 2 / 4;
}

.card-bar {
  grid-column: 1 / 2;
}

.card-activity {
  grid-column: 2 / 3;
  grid-row: 3 / 4;
}

.card-performance {
  grid-column: 1 / 2;
  grid-row: 3 / 4;
}

/* Card Header */
.card-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 20px;
}

.card-title {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: -0.01em;
}

.card-subtitle {
  font-size: 0.78rem;
  color: var(--text-muted);
  margin-top: 3px;
}

.icon-btn-sm {
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: none;
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-xs);
  color: var(--text-muted);
  cursor: pointer;
  transition: all 0.2s;
}

.icon-btn-sm:hover {
  background: rgba(255, 255, 255, 0.04);
  color: var(--text-primary);
}

/* Chart Toggle */
.chart-toggle {
  display: flex;
  background: rgba(255, 255, 255, 0.04);
  border-radius: var(--radius-xs);
  padding: 3px;
  gap: 2px;
}

.toggle-btn {
  padding: 6px 14px;
  border: none;
  background: none;
  color: var(--text-muted);
  font-size: 0.75rem;
  font-weight: 600;
  border-radius: 4px;
  cursor: pointer;
  transition: all 0.2s;
  font-family: inherit;
}

.toggle-btn.active {
  background: var(--gradient-accent);
  color: white;
  box-shadow: 0 2px 8px rgba(139, 92, 246, 0.3);
}

.toggle-btn:not(.active):hover {
  color: var(--text-secondary);
  background: rgba(255, 255, 255, 0.04);
}

/* Chart Containers */
.chart-container {
  position: relative;
}

.chart-large {
  height: 320px;
}

.chart-donut-wrap {
  position: relative;
  height: 220px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.donut-center {
  position: absolute;
  display: flex;
  flex-direction: column;
  align-items: center;
  pointer-events: none;
}

.donut-total {
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--text-primary);
  letter-spacing: -0.02em;
}

.donut-label {
  font-size: 0.72rem;
  color: var(--text-muted);
  margin-top: 2px;
}

/* Donut Legend */
.donut-legend {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin-top: 16px;
}

.legend-item {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.78rem;
  color: var(--text-secondary);
}

.legend-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  flex-shrink: 0;
}

.legend-value {
  margin-left: auto;
  font-weight: 600;
  color: var(--text-primary);
  font-variant-numeric: tabular-nums;
}

/* Activity Feed */
.activity-list {
  display: flex;
  flex-direction: column;
  gap: 4px;
  max-height: 360px;
  overflow-y: auto;
}

.activity-list::-webkit-scrollbar { width: 4px; }
.activity-list::-webkit-scrollbar-track { background: transparent; }
.activity-list::-webkit-scrollbar-thumb { background: var(--border-subtle); border-radius: 4px; }

.activity-item {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 12px;
  border-radius: var(--radius-sm);
  transition: background 0.2s;
}

.activity-item:hover {
  background: rgba(255, 255, 255, 0.03);
}

.activity-icon {
  width: 36px;
  height: 36px;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.activity-icon.success { background: rgba(52, 211, 153, 0.12); color: var(--green); }
.activity-icon.info    { background: rgba(96, 165, 250, 0.12); color: var(--blue); }
.activity-icon.warning { background: rgba(251, 191, 36, 0.12); color: var(--yellow); }

.activity-content {
  flex: 1;
  min-width: 0;
}

.activity-title {
  display: block;
  font-size: 0.84rem;
  font-weight: 500;
  color: var(--text-primary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.activity-meta {
  display: block;
  font-size: 0.72rem;
  color: var(--text-muted);
  margin-top: 2px;
}

.activity-time {
  font-size: 0.72rem;
  color: var(--text-muted);
  flex-shrink: 0;
  white-space: nowrap;
}

.view-all-link {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--accent-start);
  text-decoration: none;
  transition: color 0.2s;
}

.view-all-link:hover {
  color: var(--accent-end);
}

/* Gauge Grid */
.gauge-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.gauge-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
}

.gauge-item canvas {
  width: 100px !important;
  height: 100px !important;
}

.gauge-info {
  text-align: center;
}

.gauge-value {
  display: block;
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-primary);
}

.gauge-label {
  display: block;
  font-size: 0.72rem;
  color: var(--text-muted);
  margin-top: 2px;
}

/* ============================================================
   ANIMATIONS
   ============================================================ */
@keyframes fadeSlideUp {
  from { opacity: 0; transform: translateY(16px); }
  to   { opacity: 1; transform: translateY(0); }
}

@keyframes fadeSlideDown {
  from { opacity: 0; transform: translateY(-10px); }
  to   { opacity: 1; transform: translateY(0); }
}

@keyframes countUp {
  from { opacity: 0; }
  to   { opacity: 1; }
}

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 1400px) {
  .kpi-row {
    grid-template-columns: repeat(2, 1fr);
  }
  .content-grid {
    grid-template-columns: 1fr 1fr;
  }
  .card-main-chart {
    grid-column: 1 / -1;
  }
  .card-donut {
    grid-column: 2 / 3;
    grid-row: auto;
  }
  .card-bar {
    grid-column: 1 / 2;
  }
  .card-activity {
    grid-column: 2 / 3;
  }
  .card-performance {
    grid-column: 1 / -1;
  }
  .gauge-grid {
    grid-template-columns: repeat(4, 1fr);
  }
}

@media (max-width: 1024px) {
  .sidebar { display: none; }
  .main { margin-left: 0; padding: 20px; }
  .content-grid { grid-template-columns: 1fr; }
  .card-main-chart,
  .card-donut,
  .card-bar,
  .card-activity,
  .card-performance { grid-column: 1 / -1; }
  .gauge-grid { grid-template-columns: repeat(2, 1fr); }
  .kpi-row { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 640px) {
  .kpi-row { grid-template-columns: 1fr; }
  .topbar { flex-direction: column; align-items: flex-start; gap: 16px; }
  .topbar-right { width: 100%; }
  .search-box { flex: 1; }
  .search-box input { width: 100%; }
}