/* Import Google Font (Inter) for premium modern typography */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&display=swap');

/* --- Reset & Global Theme Config --- */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

:root {
  /* Color Palette - Vibrant Dark Mode */
  --bg-gradient-start: #0a0b10;
  --bg-gradient-end: #141624;
  --card-bg: rgba(22, 25, 41, 0.7);
  --card-bg-hover: rgba(30, 34, 54, 0.85);
  --card-border: rgba(255, 255, 255, 0.08);
  --card-border-hover: rgba(255, 255, 255, 0.15);
  --text-main: #f3f4f6;
  --text-muted: #9ca3af;
  --text-accent: #38bdf8;
  
  /* Feature Colors */
  --color-gsr: #22d3ee;        /* Teal/Cyan */
  --color-speed: #a78bfa;      /* Purple/Lavender */
  --color-sweat: #fb923c;      /* Amber/Orange */
  --color-subjective: #f43f5e; /* Rose/Crimson */
  
  /* Status Colors */
  --color-success: #10b981;
  --color-danger: #ef4444;
  
  /* Shadows & Blur */
  --card-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.37);
  --glass-blur: 16px;
  
  /* Transition Speed */
  --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-normal: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

body {
  background: radial-gradient(circle at 50% 50%, var(--bg-gradient-end), var(--bg-gradient-start));
  color: var(--text-main);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  line-height: 1.5;
  overflow-x: hidden;
}

/* Custom Scrollbar */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}
::-webkit-scrollbar-track {
  background: var(--bg-gradient-start);
}
::-webkit-scrollbar-thumb {
  background: rgba(255, 255, 255, 0.1);
  border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover {
  background: rgba(255, 255, 255, 0.2);
}

/* --- Layout Grid --- */
.container {
  max-width: 1400px;
  width: 100%;
  margin: 0 auto;
  padding: 1.5rem 2rem;
  flex-grow: 1;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

/* Header & Title Area */
header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.5rem;
  flex-wrap: wrap;
  gap: 1rem;
}

.brand-section {
  display: flex;
  flex-direction: column;
}

.brand-title {
  font-size: 1.75rem;
  font-weight: 700;
  letter-spacing: -0.025em;
  background: linear-gradient(135deg, #ffffff 30%, #38bdf8 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.brand-subtitle {
  font-size: 0.875rem;
  color: var(--text-muted);
}

/* Glassmorphism Card Template */
.glass-card {
  background: var(--card-bg);
  backdrop-filter: blur(var(--glass-blur));
  -webkit-backdrop-filter: blur(var(--glass-blur));
  border: 1px solid var(--card-border);
  border-radius: 1rem;
  box-shadow: var(--card-shadow);
  transition: border var(--transition-fast), background var(--transition-fast), transform var(--transition-normal);
}

.glass-card:hover {
  border-color: var(--card-border-hover);
  background: var(--card-bg-hover);
}

/* --- Drag & Drop Upload Zone --- */
.upload-container {
  width: 100%;
  margin-bottom: 0.5rem;
}

.upload-zone {
  padding: 2rem;
  text-align: center;
  border: 2px dashed var(--card-border);
  border-radius: 1rem;
  cursor: pointer;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
  background: rgba(22, 25, 41, 0.4);
  transition: all var(--transition-normal);
  position: relative;
  overflow: hidden;
}

.upload-zone.dragover {
  border-color: var(--text-accent);
  background: rgba(56, 189, 248, 0.08);
  box-shadow: 0 0 20px rgba(56, 189, 248, 0.2);
}

.upload-icon {
  font-size: 2.5rem;
  color: var(--text-accent);
  transition: transform var(--transition-fast);
}

.upload-zone:hover .upload-icon {
  transform: translateY(-4px);
}

.upload-text {
  font-weight: 500;
  font-size: 1rem;
}

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

#file-input {
  display: none;
}

/* --- Dashboard Grid Layout --- */
.dashboard-grid {
  display: grid;
  grid-template-columns: 300px 1fr;
  gap: 1.5rem;
  align-items: stretch;
}

@media (max-width: 1024px) {
  .dashboard-grid {
    grid-template-columns: 1fr;
  }
}

/* --- File List / Sidebar Switcher --- */
.sidebar {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  height: 100%;
  max-height: 550px;
}

.section-title {
  font-size: 1rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--card-border);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.file-list {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  overflow-y: auto;
  padding-right: 0.25rem;
  flex-grow: 1;
}

.file-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.85rem 1rem;
  border-radius: 0.75rem;
  cursor: pointer;
  border: 1px solid var(--card-border);
  transition: all var(--transition-fast);
}

.file-item.active {
  border-color: var(--text-accent);
  background: rgba(56, 189, 248, 0.1);
  box-shadow: 0 0 15px rgba(56, 189, 248, 0.05);
}

.file-item-info {
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
  width: 80%;
}

.file-name {
  font-size: 0.875rem;
  font-weight: 500;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

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

.file-item-actions {
  opacity: 0;
  transition: opacity var(--transition-fast);
}

.file-item:hover .file-item-actions {
  opacity: 1;
}

.btn-icon-delete {
  background: transparent;
  border: none;
  color: var(--color-danger);
  cursor: pointer;
  padding: 0.25rem;
  border-radius: 0.25rem;
  transition: background var(--transition-fast);
  display: flex;
  align-items: center;
  justify-content: center;
}

.btn-icon-delete:hover {
  background: rgba(239, 68, 68, 0.15);
}

/* Empty State Styles */
.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 3rem;
  text-align: center;
  color: var(--text-muted);
  gap: 1rem;
}

.empty-state-icon {
  font-size: 3rem;
  opacity: 0.3;
}

/* --- Main Visualization Card --- */
.main-chart-card {
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
  min-height: 480px;
}

.chart-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.chart-title-group {
  display: flex;
  flex-direction: column;
}

.active-file-title {
  font-size: 1.15rem;
  font-weight: 600;
}

.chart-legend-custom {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}

.legend-badge {
  display: flex;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.75rem;
  font-weight: 500;
  padding: 0.25rem 0.6rem;
  border-radius: 0.5rem;
  background: rgba(255, 255, 255, 0.05);
  cursor: pointer;
  user-select: none;
  transition: all var(--transition-fast);
}

.legend-badge:hover {
  background: rgba(255, 255, 255, 0.1);
}

.legend-badge.hidden {
  opacity: 0.35;
  text-decoration: line-through;
}

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

.legend-dot.gsr { background-color: var(--color-gsr); box-shadow: 0 0 6px var(--color-gsr); }
.legend-dot.speed { background-color: var(--color-speed); box-shadow: 0 0 6px var(--color-speed); }
.legend-dot.sweat { background-color: var(--color-sweat); box-shadow: 0 0 6px var(--color-sweat); }
.legend-dot.subjective { background-color: var(--color-subjective); box-shadow: 0 0 6px var(--color-subjective); }

.chart-wrapper {
  position: relative;
  flex-grow: 1;
  width: 100%;
  height: 380px;
}

/* --- Metadata Dashboard Panels --- */
.metadata-section {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin-top: 0.5rem;
}

.metadata-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 1rem;
}

.meta-card {
  padding: 1rem 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  position: relative;
  overflow: hidden;
}

.meta-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 4px;
  height: 100%;
  background: var(--text-accent);
  opacity: 0.7;
}

.meta-card.env::before { background: #34d399; } /* Green */
.meta-card.user::before { background: #f472b6; } /* Pink */
.meta-card.gear::before { background: #fbbf24; } /* Amber */
.meta-card.comments-card::before { background: #a78bfa; } /* Lavender */

.meta-label {
  font-size: 0.75rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
}

.meta-value {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text-main);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.comments-card {
  grid-column: 1 / -1;
}

.comments-text {
  font-size: 0.875rem;
  color: var(--text-main);
  line-height: 1.6;
  white-space: pre-wrap;
}

/* --- Correlation Panel --- */
.correlation-section {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
  margin-top: 0.5rem;
}

@media (max-width: 900px) {
  .correlation-section {
    grid-template-columns: 1fr;
  }
}

.correlation-card {
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.correlation-matrix-grid {
  display: grid;
  gap: 0.5rem;
  overflow-x: auto;
  padding: 0.5rem 0;
}

/* Heatmap Grid Cell */
.heatmap-cell {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 0.5rem;
  border-radius: 0.375rem;
  font-size: 0.75rem;
  font-weight: 600;
  aspect-ratio: 1;
  text-align: center;
  min-width: 60px;
  color: #fff;
  text-shadow: 0 1px 2px rgba(0,0,0,0.5);
  transition: transform var(--transition-fast);
}

.heatmap-cell:hover {
  transform: scale(1.05);
  z-index: 1;
}

.heatmap-label {
  font-size: 0.6rem;
  opacity: 0.8;
  font-weight: 400;
  margin-bottom: 0.15rem;
  text-transform: uppercase;
}

.heatmap-headers {
  display: flex;
  gap: 0.5rem;
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--text-muted);
}

/* Correlation Interactive Tool */
.correlation-controls {
  display: flex;
  gap: 1rem;
  margin-bottom: 1rem;
  flex-wrap: wrap;
}

.select-wrapper {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  flex-grow: 1;
  min-width: 140px;
}

.select-wrapper label {
  font-size: 0.75rem;
  color: var(--text-muted);
}

.select-control {
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--card-border);
  border-radius: 0.5rem;
  color: var(--text-main);
  padding: 0.5rem;
  font-size: 0.875rem;
  outline: none;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.select-control:focus {
  border-color: var(--text-accent);
  background: rgba(255, 255, 255, 0.08);
}

.correlation-stats {
  display: flex;
  gap: 1.5rem;
  padding: 1rem;
  border-radius: 0.75rem;
  background: rgba(255, 255, 255, 0.03);
  align-items: center;
  justify-content: space-around;
  border: 1px solid var(--card-border);
}

.stat-box {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.stat-num {
  font-size: 1.5rem;
  font-weight: 700;
}

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

/* Custom Range Inputs for prediction sliders */
input[type="range"].select-control {
  -webkit-appearance: none;
  width: 100%;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid var(--card-border);
  height: 6px;
  border-radius: 3px;
  outline: none;
  cursor: pointer;
  padding: 0;
  transition: all var(--transition-fast);
}

input[type="range"].select-control::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--text-accent);
  box-shadow: 0 0 8px rgba(56, 189, 248, 0.5);
  cursor: pointer;
  transition: transform var(--transition-fast), background var(--transition-fast);
  border: none;
}

input[type="range"].select-control::-webkit-slider-thumb:hover {
  transform: scale(1.2);
  background: #fff;
}

input[type="range"].select-control::-moz-range-thumb {
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--text-accent);
  box-shadow: 0 0 8px rgba(56, 189, 248, 0.5);
  cursor: pointer;
  transition: transform var(--transition-fast), background var(--transition-fast);
  border: none;
}

input[type="range"].select-control::-moz-range-thumb:hover {
  transform: scale(1.2);
  background: #fff;
}

/* Footer Info */
footer {
  text-align: center;
  padding: 2rem;
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-top: auto;
  border-top: 1px solid var(--card-border);
}