@font-face {
  font-family: 'JetBrains Mono';
  font-style: normal;
  font-weight: 400;
  font-display: swap;
  src: url('https://cdn.jsdelivr.net/npm/jetbrains-mono@latest/fonts/webfonts/JetBrainsMono-Regular.woff2') format('woff2');
}

@font-face {
  font-family: 'JetBrains Mono';
  font-style: normal;
  font-weight: 700;
  font-display: swap;
  src: url('https://cdn.jsdelivr.net/npm/jetbrains-mono@latest/fonts/webfonts/JetBrainsMono-Bold.woff2') format('woff2');
}

:root {
  --bg-color: #ebf4fa;
  --text-color: #2a3f4f;
  --header-bg: #ffffff;
  --header-shadow: rgba(42, 63, 79, 0.07);
  --footer-bg: #eafafa;
  --footer-border: #cce0e0;
  --subtle-text-color: #6a7f8f;
  --link-color: #008080;
  --link-hover-color: #006060;
  --button-text: #008080;
  --button-bg: #ebf4fa;
  --button-border: 1px solid #008080;
  --button-hover-bg: #12a4a430;
  --button-hover-border: 1px solid #006060;
  --input-border: #b0c0c0;
  --input-bg: #ffffff;
  --input-focus-border: #008080;
  --item-bg: transparent;
  --item-hover-bg: #2a979729;
  --item-border: #d8eeee;
  --item-index-color: #6a7f8f;
  --item-value-color: #2a3f4f;
  --leading-zeros-color: #9ab0c0;
  --leading-zeros-opacity: 0.8;
  --info-bg: rgba(255, 255, 255, 0.95);
  --info-shadow: rgba(42, 63, 79, 0.1);
  --info-border: 1px solid #d8eeee;
  --error-bg: #ffe0e0;
  --error-text: #a03030;
  --scrollbar-thumb: #9ab0c0;
  --scrollbar-track: #eafafa;
  --scrollbar-thumb-border: #eafafa;

  --sans-serif-font: "JetBrains Mono", -apple-system, BlinkMacSystemFont,
    "Segoe UI", Roboto, Helvetica, Arial, sans-serif, "Apple Color Emoji",
    "Segoe UI Emoji", "Segoe UI Symbol";
  --monospace-font: "JetBrains Mono", "SFMono-Regular", Consolas,
    "Liberation Mono", Menlo, Courier, monospace;

  --item-height: 30px;
  --border-radius: 8px;
  --panel-width: 20px;
}

body.dark-mode {
  --bg-color: #282a36;
  --text-color: #f8f8f2;
  --header-bg: #44475a;
  --header-shadow: rgba(0, 0, 0, 0.2);
  --footer-bg: #44475a;
  --footer-border: #6272a4;
  --subtle-text-color: #48b4b9;
  --link-color: #bd93f9;
  --link-hover-color: #ff79c4;
  --button-bg: #282a36;
  --button-text: #f8f8f2;
  --button-border: 1px solid #bd93f9;
  --button-hover-bg: #ff79c4;
  --button-hover-border: 1px solid #ff79c4;
  --input-border: #6272a4;
  --input-bg: #282a36;
  --input-focus-border: #bd93f9;
  --item-bg: transparent;
  --item-hover-bg: #44475a;
  --item-border: #44475a;
  --item-index-color: #987ac4;
  --item-value-color: #f8f8f2;
  --leading-zeros-color: #6272a4;
  --leading-zeros-opacity: 0.7;
  --info-bg: rgba(40, 42, 54, 0.95);
  --info-shadow: rgba(0, 0, 0, 0.3);
  --info-border: 1px solid #6272a4;
  --error-bg: #4d1f1f;
  --error-text: #ff5555;
  --scrollbar-thumb: #6272a4;
  --scrollbar-track: #282a36;
  --scrollbar-thumb-border: #282a36;
}

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

html,
body {
  height: 100%;
  font-family: var(--sans-serif-font);
  line-height: 1.6;
  color: var(--text-color);
  background-color: var(--bg-color);
  transition: background-color 0.2s, color 0.2s;
}

header {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  background-color: var(--header-bg);
  padding: 10px 10px;
  box-shadow: 0 1px 3px var(--header-shadow);
  z-index: 100;
  text-align: center;
  height: auto;
  transition: background-color 0.2s, box-shadow 0.2s;
  border-bottom: 1px solid var(--footer-border);
}

h1 {
  font-size: 1.5rem;
  margin-bottom: 1px;
  font-weight: 600;
}

header p {
  color: var(--subtle-text-color);
  margin-bottom: 10px;
  font-size: 0.9rem;
}

.search-container {
  display: flex;
  justify-content: center;
  gap: 10px;
  max-width: 400px;
  margin: 0 auto;
  padding: 0 10px;
}

.search-container input[type="text"] {
  padding: 8px 12px;
  border: 1px solid var(--input-border);
  background-color: var(--input-bg);
  color: var(--text-color);
  border-radius: var(--border-radius);
  font-size: 1rem;
  font-family: var(--monospace-font);
  flex-grow: 1;
  min-width: 150px;
  transition: border-color 0.2s, background-color 0.2s, color 0.2s;
}

.search-container input[type="text"]:focus {
  border-color: var(--input-focus-border);
  outline: none;
  box-shadow: 0 0 0 2px rgba(var(--input-focus-border), 0.3);
}

button {
  padding: 8px 16px;
  background-color: var(--button-bg);
  color: var(--button-text);
  border: var(--button-border);
  border-radius: 0px;
  cursor: pointer;
  font-size: 1rem;
  font-family: var(--sans-serif-font);
  font-weight: 500;
  transition: background-color 0.2s, border-color 0.2s, color 0.2s;
}

button:hover {
  background-color: var(--button-hover-bg);
  border-color: var(--button-hover-border);
}

#current-info {
  position: fixed;
  top: 15px;
  right: 20px;
  background-color: var(--info-bg);
  padding: 6px 10px;
  border-radius: var(--border-radius);
  box-shadow: 0 1px 3px var(--info-shadow);
  font-family: var(--monospace-font);
  font-size: 0.55rem;
  z-index: 110;
  white-space: nowrap;
  color: var(--text-color);
  border: var(--info-border);
  transition: background-color 0.2s, color 0.2s, border-color 0.2s;
}

#viewport {
  position: absolute;
  top: 130px;
  bottom: 40px;
  left: var(--panel-width);
  right: 0;
  overflow: hidden;
}

.side-panel {
  position: absolute;
  top: 130px;
  bottom: 40px;
  left: 0;
  width: var(--panel-width);
  display: flex;
  flex-direction: column;
  z-index: 150;
  user-select: none;
  touch-action: none;
}

.side-panel .panel-btn {
  padding-left: 0;
  padding-right: 0;
  display: flex;
  justify-content: center;
  align-items: center;
  user-select: none;
  -webkit-user-select: none;
  -ms-user-select: none;
  -webkit-touch-callout: none;
  touch-action: none;
}

.panel-btn {
  flex: 1;
  border: 0px;
  border-left: none;
  background-color: var(--button-bg);
  color: var(--button-text);
  font-size: 1rem;
  cursor: pointer;
  user-select: none;
  touch-action: none;
  transition: background-color 0.2s, border-color 0.2s;
}

.panel-btn:first-child {
  border-top-left-radius: 0px;
  border-top-right-radius: 0px;
}

.panel-btn:last-child {
  border-bottom-left-radius: 0px;
  border-bottom-right-radius: 0px;
}

.panel-btn:hover {
  background-color: var(--footer-border);
}

#scrollableDiv {
  height: 100%;
  width: 100%;
  overflow-y: scroll;
  overflow-x: hidden;
  -webkit-overflow-scrolling: touch;
  -ms-overflow-style: scrollbar;
  position: relative;
  touch-action: auto;
  scrollbar-width: auto;
  scrollbar-color: var(--scrollbar-thumb) var(--scrollbar-track);
  overscroll-behavior: none;
}

#scrollableDiv::-webkit-scrollbar {
  width: 16px;
}

#scrollableDiv::-webkit-scrollbar-thumb {
  background-color: var(--scrollbar-thumb);
  border-radius: 5px;
  border: 2px solid var(--scrollbar-thumb-border);
}

#scrollableDiv::-webkit-scrollbar-track {
  background-color: var(--scrollbar-track);
  border-radius: 5px;
}

#scrollHeight {
  width: 1px;
  float: left;
  visibility: hidden;
}

#fibonacci-container {
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  max-width: 800px;
  margin: 0 auto;
  padding: 0 15px;
  will-change: transform;
}

.fibonacci-item {
  position: absolute;
  left: 15px;
  right: 15px;
  cursor: default;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 5px 10px;
  background-color: var(--item-bg);
  border-bottom: 1px solid var(--item-border);
  border-radius: 0;
  font-family: var(--monospace-font);
  font-size: 1.0rem;
  box-sizing: border-box;
  overflow: hidden;
  will-change: transform;
  height: var(--item-height) !important;
  transition: background-color 0.15s, border-color 0.2s;
}

.fibonacci-item:hover {
  background-color: var(--item-hover-bg);
}

.fibonacci-item .index {
  color: var(--item-index-color);
  font-size: 0.75rem;
  min-width: 80px;
  flex-shrink: 0;
  padding-right: 15px;
  text-align: left;
  font-family: var(--sans-serif-font);
}

.fibonacci-value {
  color: var(--item-value-color);
  word-break: keep-all;
  white-space: nowrap;
  text-align: right;
  flex-grow: 1;
  transition: color 0.2s;
}

.leading-zeros {
  color: var(--leading-zeros-color);
  opacity: var(--leading-zeros-opacity);
  transition: color 0.2s;
}

footer {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 20px;
  background-color: var(--footer-bg);
  color: var(--subtle-text-color);
  font-size: 0.8rem;
  border-top: 1px solid var(--footer-border);
  height: 40px;
  z-index: 100;
  transition: background-color 0.2s, border-color 0.2s, color 0.2s;
}

footer p {
  margin: 0;
}

footer a {
  color: var(--link-color);
  text-decoration: none;
}

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

#theme-toggle {
  background: none;
  border: 1px solid var(--input-border);
  color: var(--subtle-text-color);
  padding: 4px 8px;
  font-size: 0.75rem;
  border-radius: var(--border-radius);
  cursor: pointer;
  font-family: var(--sans-serif-font);
  transition: color 0.2s, border-color 0.2s, background-color 0.2s;
}

#theme-toggle:hover {
  background-color: var(--item-hover-bg);
  color: var(--text-color);
  border-color: var(--subtle-text-color);
}

.error {
  max-width: 600px;
  margin: 150px auto;
  text-align: center;
  padding: 30px;
  background-color: var(--error-bg);
  border: 1px solid var(--error-text);
  border-radius: var(--border-radius);
  color: var(--error-text);
  font-family: var(--sans-serif-font);
}

@media (max-width: 768px) {
  :root {
    --panel-width: 17px;
  }

  #scrollableDiv::-webkit-scrollbar {
    width: 20px;
  }
  #scrollableDiv::-webkit-scrollbar-track {
    background: var(--scrollbar-track);
  }
  #scrollableDiv::-webkit-scrollbar-thumb {
    background-color: var(--scrollbar-thumb);
    border-radius: 10px;
    border: 3px solid var(--scrollbar-track);
  }

  header {
    padding: 11px 15px;
    height: auto;
  }

  h1 {
    font-size: 1.1rem;
  }

  header p {
    font-size: 0.75rem;
    margin-bottom: 8px;
  }

  .search-container {
    flex-direction: column;
    gap: 8px;
    align-items: stretch;
    max-width: 90%;
  }

  .search-container input[type="text"] {
    font-size: 0.75rem;
  }

  #current-info {
    top: auto !important;
    right: auto !important;
    bottom: 50px !important;
    left: 5px !important;
    z-index: 200;
    font-size: 0.4rem;
  }

  #viewport {
    top: 160px;
    left: var(--panel-width);
  }

  .side-panel {
    top: 160px;
    bottom: 40px;
  }

  .fibonacci-item {
    left: 10px;
    right: 10px;
    font-size: 0.8rem;
    padding: 4px 8px;
  }

  .fibonacci-item .index {
    font-size: 0.63rem;
    min-width: 60px;
    padding-right: 3px;
  }

  footer {
    font-size: 0.65rem;
    padding: 0 10px;
  }

  #theme-toggle {
    font-size: 0.6875rem;
  }
}

@media (max-width: 480px) {
  :root {
    --panel-width: 14px;
  }

  #scrollableDiv::-webkit-scrollbar {
    width: 18px;
  }
  #scrollableDiv::-webkit-scrollbar-track {
    background: var(--scrollbar-track);
  }
  #scrollableDiv::-webkit-scrollbar-thumb {
    background-color: var(--scrollbar-thumb);
    border-radius: 10px;
    border: 3px solid var(--scrollbar-track);
  }
  
  header {
    padding: 16px 15px;
    height: auto;
  }

  h1 {
    font-size: 1.1rem;
  }

  header p {
    font-size: 0.62rem;
  }

  button {
    font-size: 0.75rem;
  }

  .search-container input[type="text"] {
    font-size: 0.68rem;
  }

  #current-info {
    left: calc(var(--panel-width) + 10px) !important;
    right: auto;
    font-size: 0.36rem;
  }

  .fibonacci-item {
    font-size: 0.65rem;
  }

  .fibonacci-item .index {
    font-size: 0.53rem;
    min-width: 50px;
    padding-right: 2px;
  }
}