:root,
:root[data-theme='light'] {
  --bg: #f2efe8;
  --surface: #fffaf3;
  --surface-strong: #ffffff;
  --text: #212420;
  --muted: #646960;
  --line: #d5d0c4;
  --accent: #2f6d67;
  --accent-strong: #255751;
  --accent-soft: #cfe8e5;
  --danger: #b64e36;
  --danger-soft: #f3d7cf;
  --select: #89bdb9;
  --shadow: 0 16px 42px rgba(28, 26, 21, 0.12);
  --ambient-a: #ffd8c4;
  --ambient-b: #c8e7eb;
  --chip-bg: rgba(255, 255, 255, 0.74);
  --radius: 18px;
}

:root[data-theme='dark'] {
  --bg: #0f1416;
  --surface: #151d21;
  --surface-strong: #1b2429;
  --text: #e8efeb;
  --muted: #afbbb6;
  --line: #2a373d;
  --accent: #63b7ae;
  --accent-strong: #7ecdc5;
  --accent-soft: rgba(74, 159, 150, 0.28);
  --danger: #e48d74;
  --danger-soft: rgba(177, 88, 61, 0.34);
  --select: #4f8b84;
  --shadow: 0 18px 44px rgba(0, 0, 0, 0.32);
  --ambient-a: #663d2d;
  --ambient-b: #1f4f59;
  --chip-bg: rgba(20, 28, 31, 0.78);
}

@media (prefers-color-scheme: dark) {
  :root[data-theme='system'] {
    --bg: #0f1416;
    --surface: #151d21;
    --surface-strong: #1b2429;
    --text: #e8efeb;
    --muted: #afbbb6;
    --line: #2a373d;
    --accent: #63b7ae;
    --accent-strong: #7ecdc5;
    --accent-soft: rgba(74, 159, 150, 0.28);
    --danger: #e48d74;
    --danger-soft: rgba(177, 88, 61, 0.34);
    --select: #4f8b84;
    --shadow: 0 18px 44px rgba(0, 0, 0, 0.32);
    --ambient-a: #663d2d;
    --ambient-b: #1f4f59;
    --chip-bg: rgba(20, 28, 31, 0.78);
  }
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  min-height: 100%;
}

body {
  font-family: "Manrope", "Noto Sans SC", sans-serif;
  color: var(--text);
  background: radial-gradient(circle at 11% 6%, color-mix(in srgb, var(--ambient-a) 68%, transparent) 0%, transparent 34%),
    radial-gradient(circle at 84% 2%, color-mix(in srgb, var(--ambient-b) 68%, transparent) 0%, transparent 42%),
    var(--bg);
  line-height: 1.5;
}

.app-shell {
  width: min(1500px, 97vw);
  margin: 24px auto 30px;
  position: relative;
  z-index: 1;
}

.hero {
  margin-bottom: 12px;
  animation: rise 380ms ease-out both;
}

.hero__head {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  gap: 16px;
}

.hero h1 {
  margin: 0 0 8px;
  font-family: "Fraunces", serif;
  font-size: clamp(2rem, 4vw, 3rem);
  letter-spacing: 0.02em;
}

.hero p {
  margin: 0;
  color: var(--muted);
  max-width: 860px;
}

.toolbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
  margin: 8px 0 10px;
}

.auto-hint {
  margin: 0;
  color: var(--muted);
  font-size: 0.9rem;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
}

.btn {
  appearance: none;
  border: 1px solid color-mix(in srgb, var(--line) 80%, var(--text) 20%);
  border-radius: 999px;
  background: var(--surface-strong);
  color: var(--text);
  padding: 9px 16px;
  font: 700 0.9rem/1 "Manrope", "Noto Sans SC", sans-serif;
  cursor: pointer;
  transition: transform 180ms ease, border-color 180ms ease, background-color 180ms ease;
}

.btn:hover {
  transform: translateY(-1px);
  border-color: var(--accent);
}

.btn:active {
  transform: translateY(0);
}

.theme-dropdown {
  position: relative;
}

.theme-trigger {
  display: inline-flex;
  align-items: center;
  gap: 7px;
}

.theme-trigger__icon,
.theme-option svg {
  width: 14px;
  height: 14px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.theme-trigger__icon svg,
.theme-option svg {
  width: 14px;
  height: 14px;
  stroke: currentColor;
  fill: none;
  stroke-width: 1.8;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.theme-caret {
  width: 14px;
  height: 14px;
  stroke: currentColor;
  fill: none;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
  transition: transform 180ms ease;
}

.theme-dropdown.is-open .theme-caret {
  transform: rotate(180deg);
}

.theme-menu {
  position: absolute;
  right: 0;
  top: calc(100% + 8px);
  min-width: 170px;
  z-index: 30;
  padding: 6px;
  border-radius: 14px;
  border: 1px solid color-mix(in srgb, var(--line) 82%, var(--text) 18%);
  background: var(--surface-strong);
  box-shadow: var(--shadow);
}

.theme-option {
  width: 100%;
  border: 1px solid transparent;
  border-radius: 10px;
  background: transparent;
  color: var(--text);
  padding: 9px 10px;
  font: 700 0.88rem/1 "Manrope", "Noto Sans SC", sans-serif;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  text-align: left;
}

.theme-option:hover {
  background: color-mix(in srgb, var(--accent) 10%, transparent);
  border-color: color-mix(in srgb, var(--accent) 30%, transparent);
}

.theme-option.is-active {
  background: color-mix(in srgb, var(--accent) 16%, transparent);
  border-color: color-mix(in srgb, var(--accent) 42%, transparent);
}

.summary {
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--chip-bg);
  padding: 10px 12px;
  margin-bottom: 12px;
}

.summary p {
  margin: 0;
}

#summaryText {
  font-size: 0.96rem;
  font-weight: 700;
  color: var(--text);
}

.editor-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.card {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: linear-gradient(180deg, var(--surface) 0%, var(--surface-strong) 100%);
  box-shadow: var(--shadow);
  overflow: hidden;
  animation: rise 420ms ease-out both;
}

.card:nth-child(2) {
  animation-delay: 80ms;
}

.editor-card {
  transition: border-color 180ms ease, box-shadow 180ms ease;
}

.editor-card:focus-within {
  border-color: color-mix(in srgb, var(--select) 70%, var(--line) 30%);
  box-shadow: var(--shadow), 0 0 0 2px color-mix(in srgb, var(--select) 78%, transparent);
}

.card__head {
  padding: 12px 14px;
  border-bottom: 1px solid var(--line);
  background: color-mix(in srgb, var(--surface-strong) 78%, transparent);
}

.card__head h2 {
  margin: 0;
  font-size: 0.98rem;
}

.text-surface {
  min-height: 520px;
  max-height: 700px;
  overflow: auto;
  padding: 14px;
  white-space: pre-wrap;
  word-break: break-word;
  font: 500 0.93rem/1.62 "IBM Plex Mono", "Cascadia Mono", monospace;
  outline: none;
  border-radius: 0 0 calc(var(--radius) - 1px) calc(var(--radius) - 1px);
}

.text-surface:focus {
  box-shadow: none;
}

.text-surface:empty::before {
  content: attr(data-placeholder);
  color: color-mix(in srgb, var(--muted) 85%, transparent);
  pointer-events: none;
}

.token--added {
  background: var(--accent-soft);
  color: var(--text);
  border-radius: 4px;
}

.token--removed {
  background: var(--danger-soft);
  color: var(--text);
  border-radius: 4px;
}

.legend {
  margin-top: 12px;
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
  color: var(--muted);
  font-size: 0.88rem;
}

.legend__tag {
  display: inline-block;
  width: 13px;
  height: 13px;
  border-radius: 3px;
  margin-right: 6px;
  vertical-align: middle;
}

.legend__tag--added {
  background: var(--accent-soft);
  border: 1px solid color-mix(in srgb, var(--accent) 48%, transparent);
}

.legend__tag--removed {
  background: var(--danger-soft);
  border: 1px solid color-mix(in srgb, var(--danger) 48%, transparent);
}

.ambient {
  position: fixed;
  z-index: 0;
  pointer-events: none;
  filter: blur(56px);
  opacity: 0.34;
}

.ambient--a {
  width: 300px;
  height: 300px;
  top: 24px;
  left: 5vw;
  background: var(--ambient-a);
}

.ambient--b {
  width: 360px;
  height: 360px;
  top: 4px;
  right: 3vw;
  background: var(--ambient-b);
}

@keyframes rise {
  from {
    transform: translateY(10px);
    opacity: 0;
  }
  to {
    transform: translateY(0);
    opacity: 1;
  }
}

@media (max-width: 980px) {
  .editor-grid {
    grid-template-columns: 1fr;
  }

  .text-surface {
    min-height: 380px;
    max-height: 560px;
  }
}

@media (max-width: 640px) {
  .app-shell {
    width: min(1500px, 96vw);
    margin-top: 16px;
  }

  .actions {
    gap: 8px;
  }

  .btn {
    padding: 9px 13px;
  }

  .theme-menu {
    min-width: 150px;
  }

  .text-surface {
    min-height: 320px;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation: none !important;
    transition: none !important;
    scroll-behavior: auto !important;
  }
}