:root {
  --bg: #0c1118;
  --panel: #141c28;
  --text: #e6edf5;
  --muted: #8b9cb3;
  --add: #1a4d3e;
  --add-fg: #5eead4;
  --del: #4a1f28;
  --del-fg: #fda4af;
  --accent: #38bdf8;
  --border: #243044;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  font-family: "Outfit", system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
}

.glow {
  position: fixed;
  inset: -20% 0 auto;
  height: 40vh;
  background: radial-gradient(ellipse at 30% 0%, rgba(56, 189, 248, 0.15), transparent 60%),
    radial-gradient(ellipse at 70% 0%, rgba(244, 114, 182, 0.1), transparent 55%);
  pointer-events: none;
  animation: drift 12s ease-in-out infinite alternate;
}

@keyframes drift {
  from { transform: translateX(-2%) scale(1); }
  to { transform: translateX(3%) scale(1.05); }
}

header {
  padding: 2rem 1.5rem 0.5rem;
  max-width: 1200px;
  margin: 0 auto;
}

h1 {
  margin: 0;
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  background: linear-gradient(120deg, #7dd3fc, #f9a8d4);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  animation: fade-up 0.6s ease-out;
}

.sub { color: var(--muted); margin: 0.35rem 0 0; }

@keyframes fade-up {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: none; }
}

.toolbar {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  align-items: center;
  max-width: 1200px;
  margin: 1rem auto;
  padding: 0 1.5rem;
}

.sync { font-size: 0.9rem; color: var(--muted); display: flex; gap: 0.4rem; align-items: center; }

button {
  font-family: inherit;
  font-weight: 600;
  border: 1px solid var(--border);
  background: var(--panel);
  color: var(--text);
  padding: 0.45rem 0.9rem;
  border-radius: 8px;
  cursor: pointer;
  transition: transform 0.15s, border-color 0.15s;
}

button:hover { border-color: var(--accent); transform: translateY(-1px); }
button.primary { background: linear-gradient(135deg, #0ea5e9, #6366f1); border: none; }

.editors {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  max-width: 1200px;
  margin: 0 auto 1.5rem;
  padding: 0 1.5rem;
}

@media (max-width: 768px) {
  .editors { grid-template-columns: 1fr; }
}

.pane label { display: block; font-size: 0.85rem; color: var(--muted); margin-bottom: 0.35rem; }

textarea {
  width: 100%;
  font-family: "Fira Code", monospace;
  font-size: 0.85rem;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 10px;
  color: var(--text);
  padding: 0.75rem;
  resize: vertical;
}

.diff-view {
  max-width: 1200px;
  margin: 0 auto 3rem;
  padding: 0 1.5rem;
}

.diff-view h2 { font-size: 1rem; color: var(--muted); font-weight: 500; }

.diff-panes {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.5rem;
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
  background: var(--panel);
}

@media (max-width: 768px) {
  .diff-panes { grid-template-columns: 1fr; }
}

.diff-col {
  margin: 0;
  padding: 0.75rem 0;
  font-family: "Fira Code", monospace;
  font-size: 0.8rem;
  overflow: auto;
  max-height: 420px;
}

.line {
  display: flex;
  gap: 0.5rem;
  padding: 0 0.75rem;
  min-height: 1.4em;
}

.line .num {
  width: 2.5rem;
  flex-shrink: 0;
  text-align: right;
  color: var(--muted);
  user-select: none;
}

.line.add { background: var(--add); color: var(--add-fg); }
.line.del { background: var(--del); color: var(--del-fg); }
.line.same { opacity: 0.85; }

.stats { font-size: 0.9rem; color: var(--muted); }

footer {
  text-align: center;
  padding: 2rem;
  color: var(--muted);
  font-size: 0.9rem;
  border-top: 1px solid var(--border);
}