:root {
  --panel-bg: #18191f;
  --panel-width: 250px;
  --panel-radius: 12px;
  --panel-shadow: 0 0 10px rgba(255, 255, 255, 0.933);
  --accent: #33cfff;
  --label-color: #b4dafb;
  --value-color: #fff;
  --font-main: "Inter", Arial, sans-serif;
}

.hidden {
  display: none !important;
}

html,
body {
  height: 100%;
  margin: 0;
  padding: 0;
  overflow: hidden;
  background: #000;
}

canvas {
  display: block;
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  pointer-events: none;
}

#modPanel,
#particleControlPanel {
  position: absolute;
  top: 0;
  height: 90vh;
  width: var(--panel-width);
  max-width: var(--panel-width);
  min-width: 260px;
  border-radius: 12px;
  background: var(--panel-bg);
  color: #fff;
  font-family: var(--font-main);
  z-index: 20;
  box-shadow: var(--panel-shadow);
  padding: 32px 20px 20px 20px;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  text-align: center;
  margin: 8px;
}

#particleControlPanel {
  left: 0;
  border-right: 1.5px solid #26273b;
}

.mod-group,
.panel-group {
  background: rgba(255, 255, 255, 0.04);
  border-radius: var(--panel-radius);
  margin-bottom: 18px;
  padding: 16px 12px 12px 12px;
  display: flex;
  flex-direction: column;
  box-shadow: 0 1px 3px #0005;
  text-align: center;
}

#particleControlPanel .panel-title {
  font-size: 1.32em;
  font-weight: 700;
  letter-spacing: 0.2px;
  color: #ffffff;
  margin-bottom: 18px;
}

.mod-row,
.panel-row {
  display: flex;
  flex-direction: column;
  gap: 0;
  margin-bottom: 8px;
}
.mod-label-below,
.panel-label-below {
  font-size: 1em;
  font-weight: 500;
  color: var(--label-color);
  margin-top: 6px;
  margin-bottom: 2px;
  text-align: left;
}
.mod-value-below,
.panel-value-below {
  font-size: 1em;
  color: var(--value-color);
  margin-top: 2px;
  margin-bottom: 2px;
}

#apply-particle-impulse,
#add-particle-electron,
#add-particle-proton,
#add-particle-neutron {
  width: 60%;
  align-self: center;
}

input[type="range"] {
  -webkit-appearance: none;
  -moz-appearance: none;
  appearance: none;
  background: rgb(125, 125, 125);
  outline: none;
  border: 1px solid #3de4e8;
  width: 150px;
  height: 6px;
  border-radius: 4px;
  cursor: pointer;
  margin: 30px;
  position: relative;
  box-shadow: inset 0 1px 2px rgba(0, 0, 0, 0.2), 0 2px 5px rgba(0, 0, 0, 0.5);
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 44px;
  height: 25px;
  border-radius: 2px;
  background: linear-gradient(
      to right,
      transparent 0%,
      transparent 10%,
      transparent 10%,
      transparent 11%,
      transparent 11%,
      transparent 16%,
      transparent 16%,
      transparent 17%,
      transparent 17%,
      transparent 22%,
      transparent 22%,
      transparent 23%,
      transparent 23%,
      transparent 28%,
      transparent 28%,
      transparent 29%,
      transparent 29%,
      transparent 34%,
      transparent 34%,
      transparent 35%,
      transparent 35%,
      transparent 40%,
      transparent 40%,
      transparent 41%,
      transparent 41%,
      transparent 46%,
      transparent 46%,
      transparent 47%,
      transparent 47%,
      transparent 52%,
      #3de4e8 52%,
      #3de4e8 53%,
      lightgreen 53%,
      lightgreen 57%,
      black 57%,
      black 58%,
      transparent 58%,
      transparent 63%,
      transparent 63%,
      transparent 64%,
      transparent 64%,
      transparent 69%,
      transparent 69%,
      transparent 70%,
      transparent 70%,
      transparent 75%,
      transparent 75%,
      transparent 76%,
      transparent 76%,
      transparent 81%,
      transparent 81%,
      transparent 82%,
      transparent 82%,
      transparent 87%,
      transparent 87%,
      transparent 88%,
      transparent 88%,
      transparent 93%,
      transparent 93%,
      transparent 94%,
      transparent 94%,
      transparent 99%,
      transparent 99%,
      transparent 100%
    ),
    linear-gradient(to bottom, #474646 0%, #474747 100%),
    linear-gradient(135deg, transparent 15%, #ffffff33 50%, transparent 85%);
  border: 2px solid #3de4e8;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.5),
    inset 0 1px 3px rgba(255, 255, 255, 0.7);
  transition: transform 0.2s, box-shadow 0.2s;
}

input[type="range"]::-moz-range-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 44px;
  height: 25px;
  border-radius: 2px;
  background: linear-gradient(
      to right,
      transparent 0%,
      transparent 10%,
      transparent 10%,
      transparent 11%,
      transparent 11%,
      transparent 16%,
      transparent 16%,
      transparent 17%,
      transparent 17%,
      transparent 22%,
      transparent 22%,
      transparent 23%,
      transparent 23%,
      transparent 28%,
      transparent 28%,
      transparent 29%,
      transparent 29%,
      transparent 34%,
      transparent 34%,
      transparent 35%,
      transparent 35%,
      transparent 40%,
      black 40%,
      black 41%,
      transparent 41%,
      transparent 46%,
      black 46%,
      black 47%,
      transparent 47%,
      transparent 52%,
      black 52%,
      black 53%,
      #3de4e8 53%,
      #3de4e8 57%,
      black 57%,
      black 58%,
      transparent 58%,
      transparent 63%,
      black 63%,
      black 64%,
      transparent 64%,
      transparent 69%,
      black 69%,
      black 70%,
      transparent 70%,
      transparent 75%,
      transparent 75%,
      transparent 76%,
      transparent 76%,
      transparent 81%,
      transparent 81%,
      transparent 82%,
      transparent 82%,
      transparent 87%,
      transparent 87%,
      transparent 88%,
      transparent 88%,
      transparent 93%,
      transparent 93%,
      transparent 94%,
      transparent 94%,
      transparent 99%,
      transparent 99%,
      transparent 100%
    ),
    linear-gradient(to bottom, #474646 0%, #474747 100%),
    linear-gradient(135deg, transparent 15%, #ffffff33 50%, transparent 85%);
  border: 2px solid #3de4e8;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.5),
    inset 0 1px 3px rgba(255, 255, 255, 0.7);
  transition: transform 0.2s, box-shadow 0.2s;
}

input[type="range"]:active::-webkit-slider-thumb {
  transform: scale(1.2);
  box-shadow: 0 8px 10px rgba(0, 0, 0, 0.7),
    inset 0 2px 5px rgba(255, 255, 255, 0.9);
}

input[type="range"]:active::-moz-range-thumb {
  transform: scale(1.2);
  box-shadow: 0 8px 10px rgba(0, 0, 0, 0.7),
    inset 0 2px 5px rgba(255, 255, 255, 0.9);
}

input[type="range"]:focus::-webkit-slider-thumb {
  transform: scale(1.2);
  box-shadow: 0 8px 10px rgba(0, 0, 0, 0.7),
    inset 0 2px 5px rgba(255, 255, 255, 0.9);
}

input[type="range"]:focus::-moz-range-thumb {
  transform: scale(1.2);
  box-shadow: 0 8px 10px rgba(0, 0, 0, 0.7),
    inset 0 2px 5px rgba(255, 255, 255, 0.9);
}

select {
  appearance: none;
  -webkit-appearance: none;
  -moz-appearance: none;
  background-color: rgb(59, 59, 59);
  color: whitesmoke;
  border: 2px solid rgb(255, 255, 255);
  border-radius: 4px;
  padding-right: 40px;
  padding-left: 15px;
  padding-top: 8px;
  padding-bottom: 8px;
  cursor: pointer;
  background-image: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="ffffff"" stroke="ffffff" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><polygon points="6 9 12 15 18 9"></polygon></svg>');
  background-repeat: no-repeat;
  background-position: calc(100% - 0.1px) center;
  margin-top: 10px;
  margin-bottom: 10px;
  width: 100%;
}

/* Hide the default arrow icon in Firefox */
select::-ms-expand {
  display: none;
}

/* Style the custom arrow icon */
select {
  background-image: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="var(--font-color, whitesmoke)" stroke="var(--font-color, whitesmoke)" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><polygon points="6 9 12 15 18 9"></polygon></svg>');
  background-repeat: no-repeat;
  background-repeat: no-repeat;
  background-position: calc(100% - 0.1px) center; /* Position further to the right */
}

button {
  background: linear-gradient(90deg, #3de4e8 0%, #67a5fd 100%);
  border: none;
  border-radius: 8px;
  padding: 8px 14px;
  margin: 8px 8px 0 0;
  color: #15161f;
  font-weight: 600;
  font-size: 1em;
  cursor: pointer;
  transition: filter 0.14s;
  box-shadow: 0 2px 10px #3de4e82c;
}
button:hover {
  filter: brightness(0.95) contrast(1.1);
}

span.slider-value,
span[id$="-value"] {
  text-align: right;
  display: block;
  font-size: 1em;
  color: var(--label-color);
  margin-top: 2px;
  margin-bottom: 2px;
}

#startButton {
  position: fixed;
  top: 20px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 1001;
  background: linear-gradient(90deg, #3de4e8 0%, #67a5fd 100%);
  color: #15161f;
  font-weight: 700;
  font-size: 1.15em;
  border: none;
  border-radius: 10px;
  padding: 12px 28px;
  box-shadow: 0 2px 10px #3de4e82c;
  cursor: pointer;
  letter-spacing: 0.04em;
  transition: filter 0.16s;
}
#startButton:hover {
  filter: brightness(0.93) contrast(1.1);
}

.colour-div {
  display: flex;
  flex-direction: column;
  text-align: center;
  justify-items: center;
}

.colour-div input[type="color"] {
  width: 90%;
  height: 40px;
}

.mod-category,
.panel-category {
  margin-bottom: 1em;
  border: 1px solid #ccc;
  border-radius: 6px;
  padding: 0.5em;
  text-align: left;
  align-items: center;
}

.mod-category-heading,
.panel-category-heading {
  font-size: 1.1em;
  margin-bottom: 0.5em;
  user-select: none;
}

#input[type="checkbox"] {
  vertical-align: middle;
  width: 99%;
}

#input[type="checkbox"] + span {
  vertical-align: middle;
}

.checkbox-container {
  display: inline-block;
  font-size: 16px;
  color: #000000;
  margin-bottom: 8px;
}

.checkbox-input {
  position: absolute;
  opacity: 0;
  cursor: pointer;
  height: 0;
  width: 0;
}

.checkbox-button {
  display: inline-block;
  padding: 10px;
  background: linear-gradient(90deg, #3de4e8 0%, #67a5fd 100%);
  border: 3px solid #67a5fd;
  border-radius: 10px;
  color: #000000;
  font-weight: 600;
  font-size: 1em;
  cursor: pointer;
}

.checkbox-input:checked ~ .checkbox-button {
  background: linear-gradient(90deg, #3de4e8 0%, #67a5fd 100%);
  border: 3px solid whitesmoke;
  border-color: #ffffff;
}

.checkbox-input:focus ~ .checkbox-button {
  outline: 2px solid whitesmoke;
  outline-offset: 2px;
}

.modal {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  color: whitesmoke;
  font-family: var(--font-main);
  background: rgba(0, 0, 0, 0.5);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1100;
}

.modal.hidden {
  display: none;
}

.modal-content {
  background: #181c20;
  border: 2px solid #36ffad;
  border-radius: 14px;
  padding: 2rem;
  width: 80%;
  height: 260px;
  position: relative;
  box-shadow: 0 0 40px #000;
  justify-items: space-between;
}

.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.5);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
}

.modal-content-2 {
  background: #181c20;
  border: 2px solid #36ffad;
  font-family: var(--font-main);
  border-radius: 14px;
  padding: 2rem;
  width: 80%;
  position: relative;
  box-shadow: 0 0 40px #000;
  justify-items: space-between;
}

.modal-close-btn {
  position: absolute;
  top: 8px;
  right: 12px;
  background: none;
  border: none;
  color: #36ffad;
  font-size: 2rem;
  cursor: pointer;
  z-index: 10;
}

.lcd-button {
  margin-bottom: 20px;
}

#midi-mapping-list {
  overflow: auto;
  font-family: var(--font-main);
  font-weight: bold;
  color: #ffffff;
  border-radius: 5px;
  border: 4px solid #404040;
  padding: 3px;
  text-shadow: 0 0 1px #504f4f;
  text-align: center;
  width: 400px;
  height: 200px;
  margin-top: 50px;
  margin-right: 20px;
}

#midi-preset-list {
  overflow: auto;
  font-family: var(--font-main);
  font-weight: bold;
  color: #ffffff;
  border-radius: 5px;
  border: 4px solid #404040;
  padding: 3px;
  text-shadow: 0 0 1px #504f4f;
  text-align: center;
  width: 400px;
  height: 200px;
  margin-top: 50px;
  margin-left: 10px;
}

#audio-preset-list {
  overflow: auto;
  font-family: var(--font-main);
  font-weight: bold;
  color: #ffffff;
  border-radius: 5px;
  border: 4px solid #404040;
  padding: 3px;
  text-shadow: 0 0 1px #504f4f;
  text-align: center;
  width: 400px;
  height: 240px;
  margin-left: 10px;
}

#midi-mapping-list ul,
#midi-preset-list ul,
#audio-preset-list ul {
  list-style: none;
  padding: 0;
}

#midi-mapping-list li,
#midi-preset-list li,
#audio-preset-list li {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 4px;
}

#midi-mapping-list .remove-btn,
#midi-preset-list .remove-btn,
#audio-preset-list .remove-btn {
  color: #182424;
  background-color: #206976;
  font-family: "LCD", monospace;
  font-weight: bold;
  border: 2px dashed black;
  font-size: 20px;
  cursor: pointer;
  margin-right: 10px;
  margin-left: 10px;
  margin-bottom: 5px;
}

#midi-mapping-list .remove-btn:focus,
#midi-preset-list .remove-btn:focus,
#audio-preset-list .remove-btn:focus {
  outline: 2px dashed black;
  outline-offset: 2px;
}

.remove-btn2 {
  border: none;
  background-color: #206976;
  font-family: "LCD", monospace;
  font-weight: bold;
  font-size: 20px;
  cursor: pointer;
  margin-bottom: 10px;
}

.visually-hidden {
  position: absolute !important;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}

.slider-container.learning {
  outline: 2px dashed yellow;
  animation: pulse 1s infinite;
}

@keyframes pulse {
  0% {
    outline-color: yellow;
  }
  50% {
    outline-color: orange;
  }
  100% {
    outline-color: yellow;
  }
}