:root {
  --bg-primary: #0b0f19;
  --bg-secondary: #131a2e;
  --bg-tertiary: #1e294b;
  
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  
  --accent-primary: #6366f1; /* Indigo */
  --accent-hover: #4f46e5;
  
  --success: #10b981; /* Emerald */
  --success-glow: rgba(16, 185, 129, 0.15);
  
  --danger: #ef4444; /* Rose */
  --danger-glow: rgba(239, 68, 68, 0.15);
  
  --warning: #f59e0b; /* Amber */
  --warning-glow: rgba(245, 158, 11, 0.15);
  
  --border-color: rgba(255, 255, 255, 0.08);
  --border-focus: rgba(99, 102, 241, 0.4);
  
  --border-radius-sm: 8px;
  --border-radius-md: 12px;
  --border-radius-lg: 20px;
  
  --font-sans: 'Outfit', 'Inter', system-ui, -apple-system, sans-serif;
  --transition-smooth: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  background-color: var(--bg-primary);
  color: var(--text-primary);
  font-family: var(--font-sans);
  line-height: 1.5;
  padding: 2rem 1.5rem;
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: flex-start;
}

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
}

/* Header Styling */
header {
  margin-bottom: 2.5rem;
  text-align: center;
}

header h1 {
  font-size: 2.5rem;
  font-weight: 700;
  background: linear-gradient(135deg, #a5b4fc 0%, #6366f1 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  margin-bottom: 0.5rem;
  letter-spacing: -0.025em;
}

header p {
  color: var(--text-secondary);
  font-size: 1.1rem;
}

header .badge {
  display: inline-block;
  background-color: var(--bg-tertiary);
  color: var(--accent-primary);
  padding: 0.25rem 0.75rem;
  border-radius: 9999px;
  font-size: 0.85rem;
  font-weight: 600;
  margin-top: 0.75rem;
  border: 1px solid var(--border-color);
}

/* Upload Section */
.upload-container {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-lg);
  padding: 2.5rem;
  text-align: center;
  box-shadow: 0 10px 30px -10px rgba(0, 0, 0, 0.5);
  margin-bottom: 2.5rem;
  position: relative;
  overflow: hidden;
  transition: var(--transition-smooth);
}

.upload-container::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--accent-primary), #ec4899);
}

.upload-zone {
  border: 2px dashed rgba(255, 255, 255, 0.15);
  border-radius: var(--border-radius-md);
  padding: 3rem 1.5rem;
  cursor: pointer;
  background-color: rgba(255, 255, 255, 0.01);
  transition: var(--transition-smooth);
}

.upload-zone:hover, .upload-zone.dragover {
  border-color: var(--accent-primary);
  background-color: rgba(99, 102, 241, 0.03);
}

.upload-icon {
  width: 64px;
  height: 64px;
  margin: 0 auto 1.25rem;
  background: var(--bg-tertiary);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--accent-primary);
  font-size: 1.5rem;
  transition: var(--transition-smooth);
}

.upload-zone:hover .upload-icon {
  transform: translateY(-5px);
  box-shadow: 0 8px 20px rgba(99, 102, 241, 0.2);
}

.upload-zone h3 {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.upload-zone p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-bottom: 1.5rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background-color: var(--accent-primary);
  color: var(--text-primary);
  border: none;
  padding: 0.75rem 1.5rem;
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: var(--border-radius-sm);
  cursor: pointer;
  transition: var(--transition-smooth);
  text-decoration: none;
}

.btn:hover {
  background-color: var(--accent-hover);
  transform: translateY(-2px);
}

.btn-secondary {
  background-color: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
}

.btn-secondary:hover {
  background-color: rgba(255, 255, 255, 0.08);
  color: var(--text-primary);
}

.download-template-link {
  display: inline-block;
  margin-top: 1.25rem;
  color: var(--accent-primary);
  font-size: 0.9rem;
  text-decoration: none;
  font-weight: 500;
}

.download-template-link:hover {
  text-decoration: underline;
}

#fileInput {
  display: none;
}

/* Dashboard Summary Cards */
.results-section {
  display: none; /* Shown dynamically */
  animation: fadeIn 0.5s ease-out;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(15px); }
  to { opacity: 1; transform: translateY(0); }
}

.grid-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1.25rem;
  margin-bottom: 2.5rem;
}

.card {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-md);
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  min-height: 140px;
  position: relative;
  overflow: hidden;
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.2);
  transition: var(--transition-smooth);
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 24px rgba(0, 0, 0, 0.3);
  border-color: rgba(255, 255, 255, 0.15);
}

.card-title {
  font-size: 0.85rem;
  font-weight: 600;
  text-transform: uppercase;
  color: var(--text-secondary);
  letter-spacing: 0.05em;
  margin-bottom: 0.5rem;
}

.card-value {
  font-size: 1.75rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.card-description {
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-top: 0.5rem;
}

/* Highlight styling on key cards */
.card-tax {
  border-left: 4px solid var(--warning);
}
.card-tax .card-value {
  color: var(--warning);
}

.card-gain {
  border-left: 4px solid var(--success);
}
.card-gain .card-value {
  color: var(--success);
}

.card-loss {
  border-left: 4px solid var(--danger);
}
.card-loss .card-value {
  color: var(--danger);
}

/* Detailed Trades View */
.table-container {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-lg);
  padding: 2rem;
  margin-bottom: 2.5rem;
  box-shadow: 0 10px 30px -10px rgba(0, 0, 0, 0.5);
  overflow: hidden;
}

.table-header-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1.5rem;
  flex-wrap: wrap;
  gap: 1rem;
}

.table-header-row h2 {
  font-size: 1.5rem;
  font-weight: 700;
}

.table-scroll {
  overflow-x: auto;
  margin: 0 -2rem;
  padding: 0 2rem;
}

table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  font-size: 0.9rem;
}

thead {
  border-bottom: 1px solid var(--border-color);
}

th {
  padding: 1rem 0.75rem;
  color: var(--text-secondary);
  font-weight: 600;
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

td {
  padding: 1rem 0.75rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.03);
}

tbody tr:hover {
  background-color: rgba(255, 255, 255, 0.01);
}

.text-profit {
  color: var(--success);
  font-weight: 600;
}

.text-loss {
  color: var(--danger);
  font-weight: 600;
}

.badge-warning {
  background-color: var(--warning-glow);
  color: var(--warning);
  padding: 0.15rem 0.4rem;
  border-radius: 4px;
  font-size: 0.75rem;
  font-weight: 600;
  border: 1px solid rgba(245, 158, 11, 0.2);
}

/* Error Alert Box */
.alert-box {
  background-color: var(--danger-glow);
  border: 1px solid rgba(239, 68, 68, 0.2);
  color: var(--danger);
  border-radius: var(--border-radius-md);
  padding: 1rem 1.5rem;
  margin-bottom: 2rem;
  display: none;
  font-weight: 500;
  font-size: 0.95rem;
}

/* Tax Explanation Banner */
.info-banner {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-md);
  padding: 1.5rem;
  margin-bottom: 2.5rem;
  display: flex;
  gap: 1rem;
  align-items: flex-start;
}

.info-banner-icon {
  font-size: 1.5rem;
  color: var(--accent-primary);
}

.info-banner-content h4 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 0.25rem;
  color: var(--text-primary);
}

.info-banner-content p {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.4;
}

/* Responsive Overrides */
@media (max-width: 768px) {
  body {
    padding: 1rem 0.75rem;
  }
  
  header h1 {
    font-size: 2rem;
  }
  
  .upload-container {
    padding: 1.5rem;
  }
  
  .table-container {
    padding: 1rem;
  }
  
  .table-scroll {
    margin: 0 -1rem;
    padding: 0 1rem;
  }
}