:root {
  --bg-color: #0f172a;
  --panel-bg: #1e293b;
  --text-primary: #f1f5f9;
  --text-secondary: #94a3b8;
  --accent-primary: #3b82f6;
  --accent-hover: #2563eb;
  --accent-secondary: #475569;
  --accent-secondary-hover: #334155;
  --border-color: rgba(255, 255, 255, 0.1);
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --item-bg: rgba(255, 255, 255, 0.02);
  --th-bg: rgba(255, 255, 255, 0.03);
  --cell-border: rgba(255, 255, 255, 0.05);
  --cell-border-hover: rgba(255, 255, 255, 0.3);
}

[data-theme="light"] {
  --bg-color: #f8fafc;
  --panel-bg: #ffffff;
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --accent-primary: #2563eb;
  --accent-hover: #1d4ed8;
  --accent-secondary: #e2e8f0;
  --accent-secondary-hover: #cbd5e1;
  --border-color: rgba(0, 0, 0, 0.1);
  --item-bg: rgba(0, 0, 0, 0.02);
  --th-bg: rgba(0, 0, 0, 0.03);
  --cell-border: rgba(0, 0, 0, 0.1);
  --cell-border-hover: rgba(0, 0, 0, 0.3);
}

body {
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  margin: 0;
  padding: 40px 20px;
  background: var(--bg-color);
  color: var(--text-primary);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3 {
  color: var(--text-primary);
  font-weight: 700;
  margin-top: 0;
}

h1 {
  font-size: 2rem;
  margin-bottom: 1rem;
  letter-spacing: -0.025em;
}

h2 {
  font-size: 1.25rem;
  margin-bottom: 1rem;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 0.75rem;
}

h3 {
  font-size: 1rem;
  color: var(--text-secondary);
  font-weight: 600;
}

p {
  color: var(--text-secondary);
  margin-bottom: 1rem;
}

.panel {
  background: var(--panel-bg);
  border-radius: var(--radius-lg);
  padding: 24px;
  margin-bottom: 24px;
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-lg);
  max-width: 1000px;
  margin-left: auto;
  margin-right: auto;
}

/* Hide result panels by default */
.panel.results-panel {
  display: none;
}

/* Grid Styling */
.grid-8x8 {
  display: grid;
  grid-template-columns: repeat(8, 40px);
  grid-template-rows: repeat(8, 40px);
  gap: 4px;
  background: var(--bg-color);
  padding: 4px;
  border-radius: var(--radius-md);
  width: fit-content;
  margin: 20px 0;
}

.cell {
  width: 40px;
  height: 40px;
  border-radius: 4px;
  cursor: pointer;
  border: 1px solid var(--cell-border);
  box-sizing: border-box;
  transition: transform 0.1s ease, border-color 0.1s ease;
}

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

/* Controls */
.controls {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-top: 20px;
  flex-wrap: wrap;
}

label {
  display: flex;
  align-items: center;
  gap: 12px;
  color: var(--text-secondary);
  font-size: 0.9rem;
  font-weight: 500;
}

input[type="range"] {
  -webkit-appearance: none;
  width: 200px;
  height: 6px;
  background: var(--bg-color);
  border-radius: 3px;
  outline: none;
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--accent-primary);
  cursor: pointer;
  transition: background 0.2s;
  box-shadow: 0 0 0 2px var(--panel-bg);
}

input[type="range"]::-webkit-slider-thumb:hover {
  background: var(--accent-hover);
}

select {
  background-color: var(--panel-bg);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
  padding: 8px 12px;
  border-radius: var(--radius-md);
  cursor: pointer;
  font-family: inherit;
  outline: none;
}

select:focus {
  border-color: var(--accent-primary);
}

/* Buttons */
button {
  padding: 10px 20px;
  border-radius: var(--radius-md);
  border: none;
  cursor: pointer;
  background: var(--accent-primary);
  color: white;
  font-weight: 600;
  font-size: 0.9rem;
  transition: all 0.2s ease;
  box-shadow: var(--shadow-sm);
}

button:hover {
  background: var(--accent-hover);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

button:active {
  transform: translateY(0);
}

button.secondary {
  background: var(--accent-secondary);
  color: var(--text-primary);
}

button.secondary:hover {
  background: var(--accent-secondary-hover);
}

/* Tables */
#coeffTable {
  border-collapse: separate;
  border-spacing: 0;
  margin-top: 20px;
  font-size: 0.9rem;
  width: 100%;
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--border-color);
}

#coeffTable th, #coeffTable td {
  padding: 12px;
  text-align: right;
  border-bottom: 1px solid var(--border-color);
  border-right: 1px solid var(--border-color);
}

#coeffTable th {
  background: var(--th-bg);
  color: var(--text-secondary);
  font-weight: 600;
  text-align: center;
}

#coeffTable tr:last-child td {
  border-bottom: none;
}

#coeffTable tr td:last-child, #coeffTable th:last-child {
  border-right: none;
}

/* Basis Grid */
.basis-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(100px, 1fr));
  gap: 16px;
  margin-top: 20px;
}

.basis-item {
  background: var(--item-bg);
  border-radius: var(--radius-md);
  padding: 12px;
  border: 1px solid var(--border-color);
  box-sizing: border-box;
  text-align: center;
  font-size: 0.75rem;
  color: var(--text-secondary);
  transition: border-color 0.2s;
}

.basis-item:hover {
  border-color: var(--accent-primary);
}

canvas {
  border-radius: 4px;
  border: 1px solid var(--border-color);
  margin-bottom: 8px;
  display: block;
  margin-left: auto;
  margin-right: auto;
}

.small-label {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.6;
  max-width: 800px;
}

/* Footer */
footer {
  text-align: center;
  padding: 40px 20px;
  margin-top: 40px;
  color: var(--text-secondary);
  font-size: 0.9rem;
  border-top: 1px solid var(--border-color);
}

footer a {
  color: var(--accent-primary);
  text-decoration: none;
  transition: color 0.2s;
}

footer a:hover {
  color: var(--accent-hover);
  text-decoration: underline;
}

/* Popup Styles */
.popup-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.7);
  display: flex;
  justify-content: center;
  align-items: center;
  z-index: 1000;
  backdrop-filter: blur(4px);
}

.popup-content {
  background: var(--panel-bg);
  padding: 24px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-lg);
  max-width: 480px;
  max-height: 90vh;
  overflow-y: auto;
  width: 90%;
  position: relative;
}

.popup-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 10px;
}

.close-button {
  background: none;
  border: none;
  font-size: 2rem;
  color: var(--text-secondary);
  cursor: pointer;
  padding: 0;
  line-height: 1;
  box-shadow: none;
}

.close-button:hover {
  color: var(--text-primary);
  background: none;
  transform: none;
  box-shadow: none;
}

.basis-grid-popup {
  display: grid;
  grid-template-columns: repeat(8, 1fr);
  gap: 4px;
}

.basis-grid-popup canvas {
  width: 100%;
  height: auto;
  border: 1px solid var(--border-color);
  border-radius: 2px;
  transition: transform 0.2s ease;
}

.basis-grid-popup canvas:hover {
  transform: scale(1.2);
  z-index: 10;
  position: relative;
  border-color: var(--accent-primary);
  box-shadow: var(--shadow-md);
}

/* Custom Scrollbar */
::-webkit-scrollbar {
  width: 10px;
  height: 10px;
}

::-webkit-scrollbar-track {
  background: var(--bg-color);
}

::-webkit-scrollbar-thumb {
  background: var(--accent-secondary);
  border-radius: 5px;
  border: 2px solid var(--bg-color);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--accent-secondary-hover);
}