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

:root {
  --accent: #00d4ff;
  --bg: #06060c;
  --panel-bg: rgba(8, 8, 18, 0.82);
  --text: #c8d8e8;
  --text-dim: #5a6a7a;
  --border: rgba(100, 180, 255, 0.08);
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: 'JetBrains Mono', monospace;
  overflow: hidden;
  width: 100vw;
  height: 100vh;
  cursor: crosshair;
}

#canvas {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  display: block;
}

#fps-counter {
  position: fixed;
  top: 12px;
  right: 16px;
  font-size: 11px;
  font-weight: 300;
  color: rgba(200, 216, 232, 0.5);
  z-index: 100;
  pointer-events: none;
  letter-spacing: 1px;
}

#brush-indicator {
  position: fixed;
  pointer-events: none;
  border: 1.5px solid rgba(0, 212, 255, 0.4);
  border-radius: 50%;
  z-index: 90;
  transform: translate(-50%, -50%);
  display: none;
  transition: width 0.1s, height 0.1s;
}

/* Panel */
#panel {
  position: fixed;
  top: 12px;
  left: 12px;
  width: 280px;
  z-index: 200;
  background: var(--panel-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--border);
  border-radius: 14px;
  overflow: hidden;
  transition: all 0.35s cubic-bezier(0.4, 0, 0.2, 1);
}

#panel.panel-collapsed #panel-body {
  max-height: 0;
  opacity: 0;
  padding: 0 16px;
  overflow: hidden;
}

#panel-header {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 16px;
  border-bottom: 1px solid var(--border);
}

#toggle-btn {
  background: none;
  border: none;
  color: var(--text-dim);
  font-size: 16px;
  cursor: pointer;
  padding: 4px;
  transition: color 0.2s;
}
#toggle-btn:hover {
  color: var(--accent);
}

#panel-title {
  font-family: 'Crimson Pro', serif;
  font-weight: 700;
  font-size: 20px;
  color: #fff;
  text-shadow: 0 0 20px rgba(0, 212, 255, 0.3);
  letter-spacing: 0.5px;
}

#panel-body {
  padding: 10px 16px 16px;
  max-height: 700px;
  opacity: 1;
  transition: all 0.35s cubic-bezier(0.4, 0, 0.2, 1);
  overflow-y: auto;
  scrollbar-width: thin;
  scrollbar-color: rgba(0,212,255,0.15) transparent;
}

.section-label {
  font-size: 9px;
  text-transform: uppercase;
  letter-spacing: 2px;
  color: var(--text-dim);
  margin-top: 12px;
  margin-bottom: 4px;
}

.param-row {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-bottom: 5px;
}

.param-row label {
  font-size: 10px;
  color: var(--text-dim);
  min-width: 52px;
  flex-shrink: 0;
}

.param-row input[type="range"] {
  flex: 1;
  height: 3px;
  -webkit-appearance: none;
  appearance: none;
  background: rgba(0, 212, 255, 0.12);
  border-radius: 2px;
  outline: none;
}

.param-row input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--accent);
  cursor: pointer;
  box-shadow: 0 0 6px rgba(0, 212, 255, 0.4);
}

.param-row input[type="range"]::-moz-range-thumb {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--accent);
  cursor: pointer;
  border: none;
}

.val {
  font-size: 10px;
  color: var(--accent);
  min-width: 36px;
  text-align: right;
  font-weight: 300;
}

.param-row select {
  flex: 1;
  background: rgba(0,0,0,0.4);
  border: 1px solid var(--border);
  border-radius: 6px;
  color: var(--text);
  font-family: 'JetBrains Mono', monospace;
  font-size: 10px;
  padding: 4px 6px;
  outline: none;
}

.param-row select:focus {
  border-color: var(--accent);
}

.button-row {
  display: flex;
  gap: 6px;
  margin-top: 14px;
  justify-content: center;
}

.button-row button {
  background: rgba(0, 212, 255, 0.08);
  border: 1px solid rgba(0, 212, 255, 0.15);
  border-radius: 8px;
  color: var(--text);
  font-size: 16px;
  padding: 8px 12px;
  cursor: pointer;
  transition: all 0.2s;
}

.button-row button:hover {
  background: rgba(0, 212, 255, 0.18);
  border-color: var(--accent);
  transform: translateY(-1px);
}

/* Help Modal */
#help-modal {
  position: fixed;
  inset: 0;
  z-index: 500;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(0,0,0,0.6);
  backdrop-filter: blur(6px);
}

#help-modal.hidden {
  display: none;
}

#help-content {
  background: rgba(10, 10, 20, 0.95);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 28px 32px;
  max-width: 440px;
  width: 90%;
}

#help-content h2 {
  font-family: 'Crimson Pro', serif;
  font-size: 22px;
  color: #fff;
  margin-bottom: 12px;
}

#help-content p {
  font-size: 12px;
  line-height: 1.7;
  color: var(--text);
  margin-bottom: 10px;
}

#help-close {
  background: var(--accent);
  color: #000;
  border: none;
  border-radius: 8px;
  padding: 8px 24px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px;
  font-weight: 700;
  cursor: pointer;
  margin-top: 8px;
}

/* Footer */
#footer {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 8px 20px;
  font-size: 10px;
  color: var(--text-dim);
  z-index: 100;
  pointer-events: none;
}

#footer a {
  color: var(--accent);
  text-decoration: none;
  pointer-events: auto;
  opacity: 0.6;
  transition: opacity 0.2s;
}

#footer a:hover {
  opacity: 1;
}

@media (max-width: 600px) {
  #panel {
    width: 240px;
    top: 8px;
    left: 8px;
  }
  #panel-body {
    max-height: 55vh;
  }
  .param-row label {
    min-width: 40px;
    font-size: 9px;
  }
}