/* Custom variables matching premium portfolio theme */
:root {
  --bg-color: #0b0f14;
  --panel-bg: rgba(15, 22, 28, 0.7);
  --border-color: rgba(255, 255, 255, 0.08);
  --primary-color: #3da9fc;
  --accent-color: #ffcc00;
  --danger-color: #ff3b30;
  --success-color: #00e676;
  --text-color: #f0f4f8;
  --text-muted: #94a3b8;
  --border-radius: 16px;
  --font-title: 'Outfit', sans-serif;
  --font-body: 'Inter', sans-serif;
}

body {
  margin: 0;
  background-color: var(--bg-color);
  color: var(--text-color);
  font-family: var(--font-body);
  display: flex;
  flex-direction: column;
  height: 100vh;
  overflow: hidden;
}

/* Header styling */
.app-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 32px;
  background: rgba(11, 15, 20, 0.8);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border-color);
  z-index: 50;
  height: 70px;
  box-sizing: border-box;
}

.back-link {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--text-muted);
  text-decoration: none;
  font-size: 14px;
  font-weight: 600;
  transition: color 0.2s, transform 0.2s;
}

.back-link:hover {
  color: var(--primary-color);
  transform: translateX(-4px);
}

.app-title {
  font-family: var(--font-title);
  font-size: 22px;
  font-weight: 800;
  margin: 0;
  background: linear-gradient(135deg, #fff 30%, var(--primary-color));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* Main Container Layout */
.app-container {
  display: flex;
  flex: 1;
  overflow: hidden;
  position: relative;
}

.workspace {
  display: flex;
  flex: 1;
  width: 100%;
  height: 100%;
  padding: 24px;
  gap: 24px;
  box-sizing: border-box;
}

@media (max-width: 1024px) {
  .workspace {
    flex-direction: column;
    overflow-y: auto;
  }
}

/* Canvas Display Area */
.canvas-wrapper {
  position: relative;
  flex: 1;
  background: #090c10;
  border-radius: var(--border-radius);
  border: 1px solid var(--border-color);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
  display: flex;
  justify-content: center;
  align-items: center;
  overflow: hidden;
  min-height: 400px;
}

#canvasElement {
  width: 100%;
  height: 100%;
  object-fit: contain;
  display: block;
}

/* On-canvas HUD Display */
.hud-overlay {
  position: absolute;
  top: 20px;
  left: 20px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  background: rgba(11, 15, 20, 0.7);
  padding: 12px 18px;
  border-radius: var(--border-radius);
  border: 1px solid var(--border-color);
  backdrop-filter: blur(8px);
  z-index: 10;
  pointer-events: none;
}

.hud-metric {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
}

.hud-metric .label {
  color: var(--text-muted);
}

.hud-metric .value {
  font-family: 'JetBrains Mono', monospace;
  color: var(--success-color);
  font-weight: 600;
}

/* Sidebar Controls Panel */
.control-panel {
  width: 360px;
  background: var(--panel-bg);
  backdrop-filter: blur(12px);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius);
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 24px;
  box-sizing: border-box;
  overflow-y: auto;
}

@media (max-width: 1024px) {
  .control-panel {
    width: 100%;
    overflow-y: visible;
  }
}

.panel-section {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.panel-section h2,
.panel-section h3 {
  font-family: var(--font-title);
  font-size: 16px;
  margin: 0;
  color: var(--primary-color);
  display: flex;
  align-items: center;
  gap: 8px;
}

/* Presets grid */
.presets-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 8px;
}

.preset-btn {
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  color: var(--text-color);
  padding: 10px;
  font-size: 13px;
  font-family: var(--font-body);
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s;
  text-align: center;
}

.preset-btn:hover {
  background: rgba(61, 169, 252, 0.1);
  border-color: rgba(61, 169, 252, 0.3);
}

.preset-btn.active {
  background: var(--primary-color);
  color: #000;
  border-color: var(--primary-color);
  font-weight: 600;
}

/* Slider Controls */
.control-group {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.slider-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 13px;
}

.slider-row label {
  color: var(--text-muted);
}

.monospaced-val {
  font-family: 'JetBrains Mono', monospace;
  color: var(--accent-color);
  font-weight: 600;
}

input[type="range"] {
  -webkit-appearance: none;
  width: 100%;
  background: rgba(255, 255, 255, 0.1);
  height: 6px;
  border-radius: 3px;
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--primary-color);
  cursor: pointer;
  box-shadow: 0 0 8px var(--primary-color);
  transition: background-color 0.15s, transform 0.15s;
}

input[type="range"]::-webkit-slider-thumb:hover {
  transform: scale(1.2);
}

/* Buttons */
.button-row {
  display: flex;
  gap: 12px;
  margin-top: 8px;
}

.btn {
  flex: 1;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border-color);
  border-radius: 10px;
  color: var(--text-color);
  padding: 12px;
  font-family: var(--font-title);
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  transition: all 0.2s;
}

.btn:hover {
  background: rgba(255, 255, 255, 0.1);
}

.btn.primary {
  background: var(--primary-color);
  color: #000;
  border-color: var(--primary-color);
}

.btn.primary:hover {
  background: #2b96e6;
  box-shadow: 0 0 12px rgba(61, 169, 252, 0.4);
}

.btn.danger {
  background: var(--danger-color);
  color: #fff;
  border-color: var(--danger-color);
}

.btn.danger:hover {
  background: #e02b20;
}

/* Toggles & Options styling */
.options-group {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.option-toggle {
  display: flex;
  align-items: center;
  cursor: pointer;
  user-select: none;
  font-size: 14px;
}

.option-toggle input {
  position: absolute;
  opacity: 0;
  cursor: pointer;
}

.toggle-slider {
  position: relative;
  width: 36px;
  height: 20px;
  background-color: rgba(255, 255, 255, 0.1);
  border-radius: 20px;
  transition: background-color 0.2s;
  margin-right: 12px;
}

.toggle-slider::before {
  content: "";
  position: absolute;
  height: 14px;
  width: 14px;
  left: 3px;
  bottom: 3px;
  background-color: var(--text-muted);
  border-radius: 50%;
  transition: transform 0.2s, background-color 0.2s;
}

.option-toggle input:checked ~ .toggle-slider {
  background-color: rgba(61, 169, 252, 0.3);
}

.option-toggle input:checked ~ .toggle-slider::before {
  transform: translateX(16px);
  background-color: var(--primary-color);
}

.toggle-label {
  color: var(--text-color);
  font-weight: 500;
}

/* Math / Formula panel */
.math-section {
  border-top: 1px solid var(--border-color);
  padding-top: 16px;
}

.formula-box {
  background: rgba(0, 0, 0, 0.3);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 12px;
  overflow-x: auto;
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px;
  color: var(--text-muted);
  line-height: 1.5;
  text-align: center;
}

/* Instructions card */
.instruction-box {
  margin-top: auto;
  background: rgba(61, 169, 252, 0.05);
  border: 1px dashed rgba(61, 169, 252, 0.2);
  border-radius: 10px;
  padding: 16px;
  font-size: 13px;
}

.instruction-box p {
  margin: 0 0 8px 0;
  color: var(--primary-color);
}

.instruction-box ul {
  margin: 0;
  padding-left: 20px;
  color: var(--text-muted);
  display: flex;
  flex-direction: column;
  gap: 4px;
}

/* Custom Scrollbar for side panel */
.control-panel::-webkit-scrollbar {
  width: 6px;
}

.control-panel::-webkit-scrollbar-track {
  background: transparent;
}

.control-panel::-webkit-scrollbar-thumb {
  background: rgba(255, 255, 255, 0.1);
  border-radius: 3px;
}

.control-panel::-webkit-scrollbar-thumb:hover {
  background: rgba(255, 255, 255, 0.2);
}

/* Accessible Focus Rings */
button:focus-visible,
.btn:focus-visible,
.preset-btn:focus-visible,
input[type="range"]:focus-visible,
.option-toggle input:focus-visible + .toggle-slider {
    outline: 2px solid var(--primary-color, #3da9fc);
    outline-offset: 2px;
}