:root {
  --bg: #f4f4f4;
  --text: #222;
  --muted: #6b6b6b;
  --nav-bg: #1b222d;
  --nav-border: #080808;
  --nav-text: #fff;
  --panel-bg: #ffffff;
  --panel-border: #dedede;
  --panel-shadow: 0 8px 20px rgba(0, 0, 0, 0.04);
  --input-bg: #fff;
  --input-border: #ced4da;
  --input-text: #222;
  --stat-border: #e2e2e2;
  --stat-text: #1b222d;
  --stat-muted: #7a7a7a;
  --diff-header-bg: #f7f7f7;
  --diff-header-border: #e1e1e1;
  --diff-header-text: #555;
  --diff-row-border: #f1f1f1;
  --diff-arrow-border: #e2e2e2;
  --diff-arrow-bg: #ffffff;
  --diff-arrow-text: #1b222d;
  --add-bg: #e9f7ef;
  --remove-bg: #fdeeee;
  --change-bg: #fff6e5;
  --equal-bg: #ffffff;
  --empty-bg: #fafafa;
  --empty-text: #b9b9b9;
  --line-number: #9b9b9b;
  --token-add-bg: rgba(46, 125, 87, 0.18);
  --token-add-text: #246b4a;
  --token-remove-bg: rgba(209, 52, 67, 0.18);
  --token-remove-text: #b22d3c;
  --empty-state: #7a7a7a;
  --about-notice-bg: #ecf0ff;
  --icon-hover-bg: rgba(255, 255, 255, 0.08);
  --modal-bg: #fff;
  --modal-text: #222;
}

body.dark {
  --bg: #10161d;
  --text: #e8edf3;
  --muted: #9ba8b5;
  --nav-bg: #0e141a;
  --nav-border: #0a0f14;
  --nav-text: #f5f7fa;
  --panel-bg: #18212b;
  --panel-border: #263342;
  --panel-shadow: 0 10px 28px rgba(0, 0, 0, 0.24);
  --input-bg: #111922;
  --input-border: #314152;
  --input-text: #edf2f7;
  --stat-border: #314152;
  --stat-text: #edf2f7;
  --stat-muted: #9fb0c0;
  --diff-header-bg: #111922;
  --diff-header-border: #263342;
  --diff-header-text: #b6c3cf;
  --diff-row-border: #263342;
  --diff-arrow-border: #314152;
  --diff-arrow-bg: #111922;
  --diff-arrow-text: #edf2f7;
  --add-bg: rgba(57, 142, 84, 0.2);
  --remove-bg: rgba(180, 77, 77, 0.18);
  --change-bg: rgba(156, 118, 38, 0.18);
  --equal-bg: #18212b;
  --empty-bg: #111922;
  --empty-text: #728295;
  --line-number: #8ea0b2;
  --token-add-bg: rgba(95, 180, 124, 0.32);
  --token-add-text: #9fd8b1;
  --token-remove-bg: rgba(212, 104, 104, 0.28);
  --token-remove-text: #f2a0a8;
  --empty-state: #9ba8b5;
  --about-notice-bg: #111922;
  --icon-hover-bg: rgba(255, 255, 255, 0.06);
  --modal-bg: #18212b;
  --modal-text: #e8edf3;
}

body {
  font-family: "Helvetica Neue", "Segoe UI", Arial, sans-serif;
  background-color: var(--bg);
  color: var(--text);
  scrollbar-gutter: stable;
  transition: background-color 180ms ease, color 180ms ease;
}

.tool-container {
  margin-top: 30px;
  margin-bottom: 60px;
}

.navbar-inverse {
  background-color: var(--nav-bg);
  border-color: var(--nav-border);
  padding: .7rem 1rem;
}

.flex-navbar {
  display: flex;
  color: white;
  font-weight: bold;
  justify-content: space-between;
  align-items: center;
  margin-right: auto;
  width: min(1107px, 100%);
  margin-left: auto;
}

.brand-container {
  display: flex;
  align-items: center;
}

.brand-title,
.brand-title:hover {
  color: var(--nav-text);
  font-weight: bold;
  font-size: 15px;
  text-decoration: none;
}

.flex-navbar-right {
  display: flex;
  align-items: center;
  gap: 12px;
}

.flex-navbar-right > span,
.flex-navbar-right > span > a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.navbar-icon-button {
  border: none;
  background: transparent;
  color: var(--nav-text);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 40px;
  border-radius: 10px;
  padding: 0;
  transition: background-color 160ms ease, color 160ms ease;
}

.navbar-icon-button:hover,
.navbar-icon-button:focus {
  background-color: var(--icon-hover-bg);
  outline: none;
}

.theme-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 20px;
  height: 20px;
}

.theme-icon svg {
  display: block;
}

#about {
  width: 36px;
  height: 40px;
  border-radius: 10px;
  color: var(--nav-text);
  transition: background-color 160ms ease, color 160ms ease;
}

#about:hover,
#about:focus {
  background-color: var(--icon-hover-bg);
  outline: none;
}

#about img {
  display: block;
}

.theme-icon-light {
  display: none;
}

body.dark .theme-icon-dark {
  display: none;
}

body.dark .theme-icon-light {
  display: inline-flex;
}

.starter-template {
  padding: 10px 0 20px;
  text-align: left;
}

.starter-template h1 {
  font-weight: 700;
  margin: 0 0 8px;
}

.starter-template p {
  color: var(--muted);
  margin: 0;
}

.tool-panel {
  background: var(--panel-bg);
  border: 1px solid var(--panel-border);
  border-radius: 12px;
  padding: 16px;
  box-shadow: var(--panel-shadow);
  margin-bottom: 16px;
}

.swap-flash {
  animation: swapPulse 0.5s ease;
  border-color: #9fc0ff;
  box-shadow: 0 0 0 3px rgba(94, 129, 244, 0.15), 0 10px 24px rgba(0, 0, 0, 0.06);
}

@keyframes swapPulse {
  0% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-2px);
  }
  100% {
    transform: translateY(0);
  }
}

.controls-panel {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 22px;
  align-items: center;
}

.controls-left {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  align-items: center;
}

.controls-right {
  display: flex;
  gap: 8px;
}

body.dark .controls-right .btn-default {
  background-color: transparent;
  border-color: transparent;
  color: #d5dfeb;
  box-shadow: none;
}

body.dark .controls-right .btn-default:hover,
body.dark .controls-right .btn-default:focus {
  background-color: rgba(255, 255, 255, 0.06);
  border-color: rgba(255, 255, 255, 0.06);
  color: #ffffff;
}

.text-panels {
  margin-bottom: 8px;
}

.text-panel-left,
.text-panel-right {
  width: 100%;
}

.swap-column {
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 16px;
}

.swap-button {
  width: 52px;
  height: 52px;
  border-radius: 50%;
  border: 1px solid #e2e2e2;
  background: #ffffff;
  color: #1b222d;
  box-shadow: 0 6px 12px rgba(0, 0, 0, 0.06);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.swap-button:hover {
  transform: translateY(-1px);
  box-shadow: 0 10px 16px rgba(0, 0, 0, 0.08);
}

@media (min-width: 992px) {
  .text-panels {
    display: flex;
    align-items: stretch;
    gap: 12px;
  }

  .text-panels > .col-sm-12 {
    float: none;
    width: auto;
  }

  .text-panel-left,
  .text-panel-right {
    flex: 1 1 0;
  }

  .swap-column {
    flex: 0 0 52px;
    margin-bottom: 0;
  }

  .swap-button {
    width: 46px;
    height: 46px;
  }
}

.checkbox-inline {
  font-weight: 500;
  color: var(--text);
  margin: 0;
  display: flex;
  gap: 5px;
  font-size: 0.9rem;
}

.panel-label {
  display: block;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--text);
}

.panel-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  margin-bottom: 8px;
}

.panel-header .panel-label {
  margin-bottom: 0;
}

.icon-button {
  width: 32px;
  height: 32px;
  border-radius: 8px;
  border: 1px solid var(--diff-arrow-border);
  background: var(--diff-arrow-bg);
  color: var(--diff-arrow-text);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0;
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.05);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.icon-button:hover {
  transform: translateY(-1px);
  box-shadow: 0 8px 14px rgba(0, 0, 0, 0.08);
}

.icon-button .icon-check {
  display: none;
}

.icon-button.copied {
  color: #2f7a4f;
  border-color: #bcdcc8;
  background: #f1fbf5;
}

body.dark .icon-button.copied {
  color: #8fd3ad;
  border-color: #2d6f55;
  background: #143126;
}

.icon-button.copied .icon-copy {
  display: none;
}

.icon-button.copied .icon-check {
  display: block;
}

textarea.form-control {
  min-height: 220px;
  resize: vertical;
  font-family: "SFMono-Regular", "Consolas", "Liberation Mono", monospace;
  font-size: 13px;
  line-height: 1.6;
  border-radius: 10px;
  background-color: var(--input-bg);
  border-color: var(--input-border);
  color: var(--input-text);
}

textarea.form-control::placeholder {
  color: var(--muted);
}

.form-control:focus {
  background-color: var(--input-bg);
  border-color: #4f88d9;
  color: var(--input-text);
  box-shadow: 0 0 0 0.2rem rgba(79, 136, 217, 0.22);
}

.stats-row {
  margin-bottom: 16px;
}

.stat-card {
  background: var(--panel-bg);
  border: 1px solid var(--stat-border);
  border-radius: 10px;
  padding: 12px 8px;
  text-align: center;
  box-shadow: var(--panel-shadow);
  margin-bottom: 12px;
}

.stat-card span {
  display: block;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--stat-muted);
}

.stat-card strong {
  font-size: 22px;
  color: var(--stat-text);
}

.diff-panel {
  padding: 0;
  overflow: hidden;
}

.diff-header {
  display: flex;
  background: var(--diff-header-bg);
  border-bottom: 1px solid var(--diff-header-border);
  font-weight: 600;
  color: var(--diff-header-text);
}

.diff-header span {
  width: 50%;
  padding: 10px 16px;
}

.diff-view {
  max-height: 520px;
  overflow: auto;
}

.diff-row {
  display: flex;
  border-bottom: 1px solid var(--diff-row-border);
  position: relative;
}

.diff-row:last-child {
  border-bottom: none;
}

.diff-cell {
  width: 50%;
  display: flex;
  gap: 10px;
  padding: 8px 12px;
  font-family: "SFMono-Regular", "Consolas", "Liberation Mono", monospace;
  font-size: 12.5px;
  line-height: 1.5;
}

.diff-row.has-action .diff-arrow {
  opacity: 0;
  pointer-events: none;
}

.diff-row.has-action:hover .diff-arrow,
.diff-row.has-action:focus-within .diff-arrow {
  opacity: 1;
  pointer-events: auto;
}

.diff-arrow {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  border: 1px solid var(--diff-arrow-border);
  background: var(--diff-arrow-bg);
  color: var(--diff-arrow-text);
  border-radius: 999px;
  width: 32px;
  height: 32px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 6px 12px rgba(0, 0, 0, 0.05);
  transition: opacity 0.2s ease, transform 0.2s ease;
  z-index: 2;
}

.diff-arrow:hover {
  transform: translate(-50%, -50%) scale(1.04);
}

.diff-cell.is-add {
  background: var(--add-bg);
}

.diff-cell.is-remove {
  background: var(--remove-bg);
}

.diff-cell.is-change {
  background: var(--change-bg);
}

.diff-cell.is-equal {
  background: var(--equal-bg);
}

.diff-cell.is-empty {
  background: var(--empty-bg);
  color: var(--empty-text);
}

.line-number {
  width: 40px;
  text-align: right;
  color: var(--line-number);
  font-variant-numeric: tabular-nums;
}

.line-text {
  white-space: pre-wrap;
  word-break: break-word;
  color: var(--input-text);
}

.token.add {
  background: var(--token-add-bg);
  color: var(--token-add-text);
}

.token.delete {
  background: var(--token-remove-bg);
  color: var(--token-remove-text);
  text-decoration: line-through;
}

.empty-state {
  padding: 24px;
  text-align: center;
  color: var(--empty-state);
}

.modal-content a {
  font-weight: bold;
}

.about-notice {
  background-color: var(--about-notice-bg);
  padding: 16px;
  border-radius: 10px;
}

.modal-content {
  background-color: var(--modal-bg);
  color: var(--modal-text);
}

body.dark .modal-header,
body.dark .modal-footer {
  border-color: var(--panel-border);
}

body.dark .modal-header .close {
  color: var(--modal-text);
  text-shadow: none;
}

body.dark .about-author-link,
body.dark .modal-body a {
  color: #7fb3ff;
}

body.dark .about-icon-container a {
  color: #ffffff;
}

body.dark .about-icon-container svg {
  fill: currentColor;
  stroke: none;
}

body.dark .about-icon-container svg path {
  fill: currentColor;
  stroke: none;
}

.about-icon-container {
  display: inline-flex;
  gap: 10px;
  float: left;
}

.btn {
  border-radius: 8px;
}

.modal-footer {
  justify-content: space-between;
}

@media (max-width: 767px) {
  .controls-panel {
    flex-direction: column;
    align-items: flex-start;
  }

  .controls-right {
    width: 100%;
    flex-wrap: wrap;
  }

  .swap-column {
    margin: -6px 0 10px;
  }

  .swap-button {
    width: 46px;
    height: 46px;
  }

  .swap-button svg {
    transform: rotate(90deg);
  }

  .diff-header {
    display: none;
  }

  .diff-row {
    flex-direction: column;
  }

  .diff-cell,
  .diff-header span {
    width: 100%;
  }

  .diff-row.has-action .diff-arrow {
    position: static;
    transform: none;
    margin: 6px auto;
    opacity: 1;
    pointer-events: auto;
  }

  .diff-row.has-action .diff-arrow svg {
    transform: rotate(90deg);
  }

  .diff-cell::before {
    content: attr(data-label);
    display: block;
    font-size: 10px;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--muted);
    margin-bottom: 4px;
    font-weight: 600;
  }
}