:root {
  color-scheme: light;
  --font: "JetBrains Mono", "SF Mono", ui-monospace, Menlo, Consolas, monospace;
  --bg: #f5f5f7;
  --panel: rgba(255, 255, 255, 0.82);
  --panel-strong: #ffffff;
  --text: #1d1d1f;
  --muted: #6e6e73;
  --border: rgba(0, 0, 0, 0.11);
  --accent: #0071e3;
  --accent-text: #ffffff;
  --shadow: 0 18px 60px rgba(0, 0, 0, 0.08);
  --added-bg: #e7f7ed;
  --added-text: #146c2e;
  --removed-bg: #fff0f0;
  --removed-text: #b42318;
  --line-bg: rgba(0, 0, 0, 0.035);
  --focus: rgba(0, 113, 227, 0.28);
  --icon-bg: linear-gradient(145deg, rgba(255, 255, 255, 0.9), rgba(219, 234, 255, 0.68));
  --icon-border: rgba(0, 113, 227, 0.14);
  --icon-shadow: 0 16px 42px rgba(0, 113, 227, 0.16), inset 0 1px 0 rgba(255, 255, 255, 0.8);
}

[data-theme="dark"] {
  color-scheme: dark;
  --bg: #101012;
  --panel: rgba(31, 31, 35, 0.78);
  --panel-strong: #1f1f23;
  --text: #f5f5f7;
  --muted: #a1a1a6;
  --border: rgba(255, 255, 255, 0.12);
  --accent: #2997ff;
  --accent-text: #07111f;
  --shadow: 0 18px 60px rgba(0, 0, 0, 0.34);
  --added-bg: rgba(38, 151, 72, 0.18);
  --added-text: #8ee0a6;
  --removed-bg: rgba(255, 69, 58, 0.16);
  --removed-text: #ff9a94;
  --line-bg: rgba(255, 255, 255, 0.055);
  --focus: rgba(41, 151, 255, 0.28);
  --icon-bg: linear-gradient(145deg, rgba(48, 48, 54, 0.92), rgba(18, 26, 39, 0.88));
  --icon-border: rgba(255, 255, 255, 0.12);
  --icon-shadow: 0 16px 42px rgba(0, 0, 0, 0.32), inset 0 1px 0 rgba(255, 255, 255, 0.08);
}

* {
  box-sizing: border-box;
}

body {
  min-height: 100vh;
  margin: 0;
  background:
    radial-gradient(circle at top left, rgba(0, 113, 227, 0.14), transparent 34rem),
    var(--bg);
  color: var(--text);
  font-family: var(--font);
}

button,
textarea {
  font: inherit;
}

button,
input,
textarea,
select {
  font-family: var(--font);
}

.shell {
  width: min(1420px, calc(100% - 32px));
  margin: 0 auto;
  padding: 44px 0;
}

.hero,
.workspace,
.actions,
.result-card {
  margin-bottom: 18px;
}

.hero {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 20px;
}

.hero-copy {
  display: grid;
  gap: 8px;
}

.app-icon {
  display: grid;
  width: 62px;
  height: 62px;
  place-items: center;
  border: 1px solid var(--icon-border);
  border-radius: 20px;
  background: var(--icon-bg);
  box-shadow: var(--icon-shadow);
}

.logo {
  display: block;
  width: 44px;
  height: 44px;
}

.eyebrow {
  margin: 0;
  color: var(--accent);
  font-size: 13px;
  font-weight: 650;
  letter-spacing: 0.01em;
  text-transform: uppercase;
}

h1,
h2,
p {
  margin-top: 0;
}

h1 {
  margin-bottom: 4px;
  font-size: clamp(32px, 4.2vw, 46px);
  font-weight: 700;
  line-height: 1.05;
  letter-spacing: -0.055em;
}

.lede {
  max-width: 640px;
  margin-bottom: 0;
  color: var(--muted);
  font-family: var(--font);
  font-size: 19px;
  font-weight: 400;
  line-height: 1.45;
}

.theme-toggle,
button {
  border: 1px solid var(--border);
  border-radius: 999px;
  cursor: pointer;
  transition: border-color 160ms ease, box-shadow 160ms ease, transform 160ms ease;
}

button:hover {
  transform: translateY(-1px);
}

button:focus-visible,
textarea:focus-visible {
  outline: 3px solid var(--focus);
  outline-offset: 2px;
}

.theme-toggle,
.secondary {
  background: var(--panel);
  color: var(--text);
}

.theme-toggle {
  padding: 10px 16px;
  backdrop-filter: blur(18px);
}

.workspace {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

.panel,
.result-card {
  border: 1px solid var(--border);
  border-radius: 26px;
  background: var(--panel);
  box-shadow: var(--shadow);
  backdrop-filter: blur(24px);
}

.panel {
  min-height: 560px;
  overflow: hidden;
}

.panel-header,
.result-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 16px 18px;
  border-bottom: 1px solid var(--border);
  color: var(--muted);
  font-size: 14px;
}

.panel-header label,
.result-header h2 {
  color: var(--text);
  font-weight: 650;
}

.result-header h2 {
  margin: 0;
  font-size: 18px;
}

textarea {
  width: 100%;
  min-height: 510px;
  resize: vertical;
  border: 0;
  background: transparent;
  color: var(--text);
  padding: 18px;
  font-size: 14px;
  line-height: 1.55;
  font-variant-numeric: tabular-nums;
}

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

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

.actions div {
  display: flex;
  gap: 10px;
}

.primary,
.secondary {
  min-height: 42px;
  padding: 0 18px;
  font-weight: 650;
}

.primary {
  border-color: transparent;
  background: var(--accent);
  color: var(--accent-text);
}

.status {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
  text-align: right;
}

.status.error {
  color: var(--removed-text);
}

.result-card {
  overflow: hidden;
}

.diff {
  min-height: 220px;
  max-height: 70vh;
  overflow: auto;
  background: var(--panel-strong);
}

.empty-state {
  padding: 40px 18px;
  color: var(--muted);
  text-align: center;
}

.diff-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  border-bottom: 1px solid var(--border);
  font-size: 13px;
  line-height: 1.5;
  font-variant-numeric: tabular-nums;
}

.diff-cell {
  display: grid;
  grid-template-columns: 58px minmax(0, 1fr);
  min-width: 0;
}

.diff-cell + .diff-cell {
  border-left: 1px solid var(--border);
}

.line-number {
  user-select: none;
  padding: 6px 10px;
  background: var(--line-bg);
  color: var(--muted);
  text-align: right;
}

.line-text {
  min-width: 0;
  padding: 6px 12px;
  overflow-wrap: anywhere;
  white-space: pre-wrap;
}

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

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

@media (max-width: 820px) {
  .shell {
    width: min(100% - 20px, 720px);
    padding: 24px 0;
  }

  .hero,
  .actions {
    flex-direction: column;
    align-items: stretch;
  }

  .workspace,
  .diff-row {
    grid-template-columns: 1fr;
  }

  .diff-cell + .diff-cell {
    border-left: 0;
    border-top: 1px solid var(--border);
  }

  .status {
    text-align: left;
  }
}