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

body {
  background: #0a0a0a;
  overflow: hidden;
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  color: #ddd;
}

canvas {
  display: block;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}

#settingsToggle {
  position: fixed;
  z-index: 100;
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.25);
  color: #fff;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  cursor: pointer;
  backdrop-filter: blur(6px);
  transition: background 0.2s;
}
#settingsToggle:hover {
  background: rgba(255, 255, 255, 0.25);
}
#settingsToggle {
  top: 12px;
  right: 12px;
  font-size: 22px;
}

#nextImageBtn,
#openImageBtn {
  position: fixed;
  z-index: 100;
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.25);
  color: #fff;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  cursor: pointer;
  backdrop-filter: blur(6px);
  transition: background 0.2s;
}
#nextImageBtn:hover,
#openImageBtn:hover {
  background: rgba(255, 255, 255, 0.25);
}
#nextImageBtn,
#openImageBtn {
  right: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.2s, opacity 0.25s;
}
#nextImageBtn.hidden,
#openImageBtn.hidden {
  opacity: 0;
  pointer-events: none;
}

#nextImageBtn {
  bottom: 60px;
}

#openImageBtn {
  bottom: 12px;
}

#settingsPanel {
  position: fixed;
  top: 60px;
  right: 12px;
  z-index: 99;
  width: 280px;
  max-height: calc(100vh - 80px);
  overflow-y: auto;
  background: rgba(20, 20, 20, 0.92);
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: 12px;
  padding: 18px;
  backdrop-filter: blur(12px);
  transition: opacity 0.25s, transform 0.25s;
}
#settingsPanel.hidden {
  opacity: 0;
  pointer-events: none;
  transform: translateY(-8px);
}
#settingsPanel h2 {
  font-size: 16px;
  margin-bottom: 12px;
  letter-spacing: 1px;
  text-transform: uppercase;
  opacity: 0.8;
}
#settingsPanel h3 {
  font-size: 13px;
  margin-top: 14px;
  margin-bottom: 6px;
  text-transform: uppercase;
  opacity: 0.6;
}
#settingsPanel label {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  margin-bottom: 10px;
}
#settingsPanel input[type=range] {
  flex: 1;
  accent-color: #888;
}
#settingsPanel span {
  min-width: 30px;
  text-align: right;
  font-variant-numeric: tabular-nums;
  opacity: 0.7;
  font-size: 12px;
}

.checkbox-label {
  cursor: pointer;
  font-size: 13px;
  margin-bottom: 10px;
  display: flex;
  align-items: center;
  gap: 6px;
}
.checkbox-label input[type=checkbox] {
  accent-color: #888;
}

#resetSettings {
  margin-top: 14px;
  width: 100%;
  padding: 8px;
  border-radius: 6px;
  border: 1px solid rgba(255, 255, 255, 0.25);
  background: rgba(255, 255, 255, 0.1);
  color: #fff;
  cursor: pointer;
  font-size: 13px;
  transition: background 0.2s;
}
#resetSettings:hover {
  background: rgba(255, 255, 255, 0.25);
}