/* ============================================================
   LLM Prompt Diff — Styles
   Theme: Dark — Electric Blue/Purple gradient, glassmorphism
   ============================================================ */

:root {
  --c-bg: #0b0d17;
  --c-surface: #12152a;
  --c-surface-2: #191d36;
  --c-border: #252b4a;
  --c-border-focus: #818cf8;
  --c-primary: #818cf8;
  --c-primary-dim: rgba(129, 140, 248, 0.12);
  --c-secondary: #3b82f6;
  --c-accent: #a78bfa;
  --c-added: #22c55e;
  --c-added-bg: rgba(34, 197, 94, 0.1);
  --c-removed: #ef4444;
  --c-removed-bg: rgba(239, 68, 68, 0.1);
  --c-text: #e2e8f0;
  --c-text-dim: #94a3b8;
  --c-text-muted: #64748b;
  --radius: 12px;
  --radius-sm: 8px;
  --radius-xs: 6px;
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
  --transition: 250ms cubic-bezier(0.4, 0, 0.2, 1);
  --shadow: 0 4px 24px rgba(0, 0, 0, 0.4);
  --glass: rgba(18, 21, 42, 0.75);
  --glass-border: rgba(37, 43, 74, 0.6);
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; scroll-behavior: smooth; }

body {
  font-family: var(--font-sans);
  background: var(--c-bg);
  color: var(--c-text);
  line-height: 1.6;
  min-height: 100vh;
  background-image:
    radial-gradient(ellipse at 20% 0%, rgba(129, 140, 248, 0.06) 0%, transparent 60%),
    radial-gradient(ellipse at 80% 100%, rgba(59, 130, 246, 0.04) 0%, transparent 60%);
}

::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--c-border); border-radius: 3px; }
::selection { background: var(--c-primary-dim); color: var(--c-primary); }
:focus-visible { outline: 2px solid var(--c-primary); outline-offset: 2px; }

/* ---------- Header ---------- */
#app-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--glass);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--glass-border);
}

.header-inner {
  max-width: 1400px;
  margin: 0 auto;
  padding: 0.75rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}

.logo-group { display: flex; align-items: center; gap: 0.75rem; }

.logo-icon {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  background: var(--c-primary-dim);
  color: var(--c-primary);
}

h1 {
  font-size: 1.25rem;
  font-weight: 700;
  background: linear-gradient(135deg, var(--c-primary), var(--c-accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.header-actions { display: flex; gap: 0.5rem; flex-wrap: wrap; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.5rem 1rem;
  font-size: 0.8125rem;
  font-weight: 500;
  font-family: var(--font-sans);
  border: none;
  border-radius: var(--radius-xs);
  cursor: pointer;
  transition: all var(--transition);
  white-space: nowrap;
}

.btn-primary {
  background: linear-gradient(135deg, var(--c-primary), var(--c-accent));
  color: #0b0d17;
  font-weight: 600;
}
.btn-primary:hover { filter: brightness(1.1); transform: translateY(-1px); box-shadow: 0 4px 20px rgba(129, 140, 248, 0.3); }

.btn-outline {
  background: transparent;
  color: var(--c-text-dim);
  border: 1px solid var(--c-border);
}
.btn-outline:hover { border-color: var(--c-primary); color: var(--c-primary); background: var(--c-primary-dim); }

.btn-ghost { background: transparent; color: var(--c-text-dim); }
.btn-ghost:hover { color: var(--c-text); background: rgba(255,255,255,0.05); }

.btn-sm { padding: 0.3rem 0.6rem; font-size: 0.75rem; }
.btn-lg { padding: 0.65rem 1.5rem; font-size: 0.875rem; }

/* ---------- Main ---------- */
#app-main {
  max-width: 1400px;
  margin: 0 auto;
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

/* ---------- Pane Grid ---------- */
.pane-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.25rem;
}

.pane-card {
  background: var(--glass);
  backdrop-filter: blur(12px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius);
  padding: 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.pane-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.pane-header h2 {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--c-text-dim);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.pane-stats { display: flex; gap: 0.5rem; }

.stat-badge {
  padding: 0.2rem 0.5rem;
  font-size: 0.6875rem;
  font-weight: 500;
  font-family: var(--font-mono);
  color: var(--c-text-muted);
  background: var(--c-surface);
  border-radius: var(--radius-xs);
}

.code-textarea {
  width: 100%;
  min-height: 250px;
  padding: 1rem;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  line-height: 1.6;
  color: var(--c-text);
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-sm);
  resize: vertical;
  transition: border-color var(--transition);
}
.code-textarea::placeholder { color: var(--c-text-muted); }
.code-textarea:focus { border-color: var(--c-primary); outline: none; }

/* ---------- Compare Row ---------- */
.compare-row {
  display: flex;
  justify-content: center;
  gap: 0.75rem;
  flex-wrap: wrap;
}

/* ---------- Panel Card ---------- */
.panel-card {
  background: var(--glass);
  backdrop-filter: blur(12px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius);
  padding: 1.25rem;
}

.panel-card h2 {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--c-text-dim);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.panel-title-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1rem;
}

.hidden { display: none !important; }

/* ---------- Diff Output ---------- */
.diff-output {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  line-height: 1.8;
  white-space: pre-wrap;
  word-break: break-word;
  padding: 1rem;
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-sm);
  max-height: 500px;
  overflow-y: auto;
}

.diff-line { padding: 0.1rem 0.4rem; border-radius: 3px; display: inline; }
.diff-added {
  background: var(--c-added-bg);
  color: var(--c-added);
  border-left: 3px solid var(--c-added);
  padding-left: 0.5rem;
}
.diff-removed {
  background: var(--c-removed-bg);
  color: var(--c-removed);
  border-left: 3px solid var(--c-removed);
  padding-left: 0.5rem;
  text-decoration: line-through;
  opacity: 0.85;
}
.diff-unchanged { color: var(--c-text-dim); }

/* Diff legend */
.diff-legend { display: flex; gap: 1rem; }
.legend-item {
  font-size: 0.75rem;
  font-weight: 500;
  display: flex;
  align-items: center;
  gap: 0.3rem;
}
.legend-item.added { color: var(--c-added); }
.legend-item.removed { color: var(--c-removed); }
.legend-item.unchanged { color: var(--c-text-muted); }

.diff-summary {
  margin-top: 0.75rem;
  padding: 0.6rem 0.75rem;
  background: var(--c-primary-dim);
  border: 1px solid rgba(129, 140, 248, 0.2);
  border-radius: var(--radius-xs);
  font-size: 0.8125rem;
  color: var(--c-text-dim);
}

/* ---------- History ---------- */
.history-list {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  max-height: 400px;
  overflow-y: auto;
}

.history-item {
  padding: 0.65rem 0.75rem;
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 0.5rem;
}
.history-item:hover { border-color: var(--c-primary); background: var(--c-surface-2); }

.history-preview {
  font-size: 0.75rem;
  font-family: var(--font-mono);
  color: var(--c-text-dim);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  flex: 1;
}

.history-time {
  font-size: 0.6875rem;
  color: var(--c-text-muted);
  white-space: nowrap;
}

.history-empty {
  text-align: center;
  padding: 2rem;
  color: var(--c-text-muted);
  font-size: 0.8125rem;
}

/* ---------- Toast ---------- */
#toast-container {
  position: fixed;
  bottom: 1.5rem;
  right: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  z-index: 1000;
}

.toast {
  padding: 0.6rem 1rem;
  font-size: 0.8125rem;
  border-radius: var(--radius-sm);
  background: var(--c-surface-2);
  border: 1px solid var(--c-border);
  color: var(--c-text);
  box-shadow: var(--shadow);
  animation: toastIn 300ms ease;
  max-width: 320px;
}
.toast.success { border-color: rgba(34, 197, 94, 0.4); }
.toast.error { border-color: rgba(239, 68, 68, 0.4); }

@keyframes toastIn {
  from { opacity: 0; transform: translateY(12px) scale(0.95); }
  to { opacity: 1; transform: translateY(0) scale(1); }
}
@keyframes toastOut {
  to { opacity: 0; transform: translateY(12px) scale(0.95); }
}

/* ---------- Responsive ---------- */
@media (max-width: 800px) {
  .pane-grid { grid-template-columns: 1fr; }
  .header-inner { flex-direction: column; align-items: flex-start; }
  .diff-legend { flex-wrap: wrap; gap: 0.5rem; }
}