/* ═══════════════════════════════════════════════
   TOT — Token Optimization Tool
   Premium Design System
   ═══════════════════════════════════════════════ */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&family=JetBrains+Mono:wght@400;500;600&display=swap');

/* ─── Design Tokens ─── */
:root {
  --bg-primary: #07070d;
  --bg-secondary: #0d0d16;
  --bg-card: rgba(15, 15, 25, 0.7);
  --bg-card-hover: rgba(20, 20, 35, 0.85);
  --bg-input: rgba(12, 12, 22, 0.9);
  --bg-glass: rgba(255, 255, 255, 0.03);

  --border: rgba(255, 255, 255, 0.06);
  --border-active: rgba(0, 212, 255, 0.3);

  --text-primary: #e8e8f0;
  --text-secondary: #8b8ba0;
  --text-muted: #55556a;

  --accent: #00d4ff;
  --accent-glow: rgba(0, 212, 255, 0.15);
  --accent-violet: #7c3aed;
  --accent-green: #22c55e;
  --accent-amber: #f59e0b;
  --accent-red: #ef4444;
  --accent-pink: #ec4899;

  --gradient-primary: linear-gradient(135deg, #00d4ff 0%, #7c3aed 100%);
  --gradient-card: linear-gradient(135deg, rgba(0,212,255,0.05) 0%, rgba(124,58,237,0.05) 100%);

  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-xl: 20px;

  --shadow-sm: 0 2px 8px rgba(0,0,0,0.3);
  --shadow-md: 0 4px 20px rgba(0,0,0,0.4);
  --shadow-lg: 0 8px 40px rgba(0,0,0,0.5);
  --shadow-glow: 0 0 30px rgba(0,212,255,0.1);

  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', monospace;

  --transition: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Light theme */
[data-theme="light"] {
  --bg-primary: #f5f5f8;
  --bg-secondary: #ebebf0;
  --bg-card: rgba(255, 255, 255, 0.85);
  --bg-card-hover: rgba(255, 255, 255, 0.95);
  --bg-input: rgba(255, 255, 255, 0.95);
  --bg-glass: rgba(0, 0, 0, 0.02);
  --border: rgba(0, 0, 0, 0.08);
  --border-active: rgba(0, 160, 200, 0.3);
  --text-primary: #1a1a2e;
  --text-secondary: #6b6b80;
  --text-muted: #9999aa;
  --shadow-sm: 0 2px 8px rgba(0,0,0,0.08);
  --shadow-md: 0 4px 20px rgba(0,0,0,0.1);
  --shadow-lg: 0 8px 40px rgba(0,0,0,0.12);
}

/* ─── Reset ─── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html {
  font-size: 15px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
}

/* Background gradient effect */
body::before {
  content: '';
  position: fixed;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background:
    radial-gradient(ellipse at 20% 20%, rgba(0,212,255,0.04) 0%, transparent 50%),
    radial-gradient(ellipse at 80% 80%, rgba(124,58,237,0.04) 0%, transparent 50%);
  pointer-events: none;
  z-index: 0;
}

/* ─── Layout ─── */
.app-container {
  position: relative;
  z-index: 1;
  max-width: 1440px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ─── Header ─── */
.app-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 0;
  border-bottom: 1px solid var(--border);
  margin-bottom: 28px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 14px;
}

.brand-logo {
  width: 42px;
  height: 42px;
  background: var(--gradient-primary);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  font-weight: 800;
  color: #fff;
  box-shadow: var(--shadow-glow);
}

.brand-text h1 {
  font-size: 1.35rem;
  font-weight: 700;
  letter-spacing: -0.5px;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.brand-text .tagline {
  font-size: 0.75rem;
  color: var(--text-muted);
  letter-spacing: 0.5px;
  text-transform: uppercase;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 8px;
}

.header-actions button {
  background: var(--bg-card);
  border: 1px solid var(--border);
  color: var(--text-secondary);
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: 0.85rem;
  font-family: var(--font-sans);
  transition: var(--transition);
}

.header-actions button:hover {
  background: var(--bg-card-hover);
  color: var(--text-primary);
  border-color: var(--border-active);
}

/* ─── Stats Bar ─── */
.stats-bar {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
  margin-bottom: 24px;
}

.stat-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 14px 18px;
  backdrop-filter: blur(10px);
  transition: var(--transition);
}

.stat-card:hover {
  border-color: var(--border-active);
  box-shadow: var(--shadow-glow);
}

.stat-card .stat-label {
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--text-muted);
  margin-bottom: 4px;
}

.stat-card .stat-value {
  font-size: 1.5rem;
  font-weight: 700;
  font-family: var(--font-mono);
  color: var(--accent);
}

.stat-card:nth-child(2) .stat-value { color: var(--accent-violet); }
.stat-card:nth-child(3) .stat-value { color: var(--accent-green); }
.stat-card:nth-child(4) .stat-value { color: var(--accent-amber); }

/* ─── Main Grid ─── */
.main-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  margin-bottom: 28px;
}

/* ─── Editor Panel ─── */
.editor-panel {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.editor-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.editor-title {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.editor-actions {
  display: flex;
  gap: 6px;
}

.editor-actions button {
  background: var(--bg-glass);
  border: 1px solid var(--border);
  color: var(--text-secondary);
  padding: 6px 14px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: 0.8rem;
  font-family: var(--font-sans);
  transition: var(--transition);
}

.editor-actions button:hover {
  background: var(--accent-glow);
  color: var(--accent);
  border-color: var(--accent);
}

.editor-actions .btn-primary {
  background: var(--gradient-primary);
  color: #fff;
  border: none;
  font-weight: 600;
}

.editor-actions .btn-primary:hover {
  opacity: 0.9;
  box-shadow: var(--shadow-glow);
}

#prompt-input {
  width: 100%;
  min-height: 400px;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 18px;
  color: var(--text-primary);
  font-family: var(--font-mono);
  font-size: 0.88rem;
  line-height: 1.7;
  resize: vertical;
  outline: none;
  transition: var(--transition);
}

#prompt-input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-glow);
}

#prompt-input::placeholder {
  color: var(--text-muted);
}

/* ─── Results Panel ─── */
.results-panel {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

/* ─── Tabs ─── */
.tabs {
  display: flex;
  gap: 2px;
  background: var(--bg-card);
  border-radius: var(--radius-md);
  padding: 3px;
  border: 1px solid var(--border);
}

.tab-btn {
  flex: 1;
  padding: 9px 12px;
  border: none;
  background: transparent;
  color: var(--text-muted);
  font-family: var(--font-sans);
  font-size: 0.8rem;
  font-weight: 500;
  cursor: pointer;
  border-radius: var(--radius-sm);
  transition: var(--transition);
}

.tab-btn:hover { color: var(--text-secondary); }

.tab-btn.active {
  background: var(--gradient-primary);
  color: #fff;
  font-weight: 600;
}

/* ─── Tab Panels ─── */
.tab-panel {
  display: none;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 18px;
  min-height: 400px;
  max-height: 500px;
  overflow-y: auto;
  backdrop-filter: blur(10px);
}

.tab-panel.active { display: block; }

/* Scrollbar */
.tab-panel::-webkit-scrollbar { width: 6px; }
.tab-panel::-webkit-scrollbar-track { background: transparent; }
.tab-panel::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 3px;
}
.tab-panel::-webkit-scrollbar-thumb:hover { background: var(--text-muted); }

.empty-state {
  color: var(--text-muted);
  font-style: italic;
  text-align: center;
  padding: 40px 20px;
}

/* ─── Optimized Preview ─── */
.optimized-text {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  line-height: 1.7;
  white-space: pre-wrap;
  word-break: break-word;
  color: var(--text-primary);
}

/* ─── Changes ─── */
.change-group {
  margin-bottom: 16px;
}

.change-group-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 8px;
  padding-bottom: 6px;
  border-bottom: 1px solid var(--border);
}

.change-category {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.change-savings {
  font-size: 0.75rem;
  color: var(--accent-green);
  font-family: var(--font-mono);
}

.change-item {
  padding: 8px 0;
  border-bottom: 1px solid rgba(255,255,255,0.02);
}

.change-rule {
  font-size: 0.78rem;
  color: var(--text-secondary);
  display: block;
  margin-bottom: 4px;
}

.change-diff {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
  font-family: var(--font-mono);
  font-size: 0.8rem;
}

.diff-old {
  background: rgba(239, 68, 68, 0.12);
  color: #fca5a5;
  padding: 2px 8px;
  border-radius: 4px;
  text-decoration: line-through;
}

.diff-new {
  background: rgba(34, 197, 94, 0.12);
  color: #86efac;
  padding: 2px 8px;
  border-radius: 4px;
}

.diff-arrow {
  color: var(--text-muted);
  font-size: 0.7rem;
}

/* ─── Suggestions ─── */
.suggestion-card {
  padding: 14px;
  border-radius: var(--radius-sm);
  margin-bottom: 10px;
  border-left: 3px solid var(--border);
}

.suggestion-error { border-left-color: var(--accent-red); background: rgba(239,68,68,0.05); }
.suggestion-warning { border-left-color: var(--accent-amber); background: rgba(245,158,11,0.05); }
.suggestion-tip { border-left-color: var(--accent-green); background: rgba(34,197,94,0.05); }

.suggestion-header {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 6px;
}

.suggestion-icon { font-size: 0.9rem; }

.suggestion-title {
  font-weight: 600;
  font-size: 0.85rem;
  color: var(--text-primary);
  flex: 1;
}

.suggestion-savings {
  font-size: 0.72rem;
  font-family: var(--font-mono);
  color: var(--accent-green);
  background: rgba(34,197,94,0.1);
  padding: 2px 8px;
  border-radius: 10px;
}

.suggestion-desc {
  font-size: 0.82rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* ─── Savings Badge ─── */
.savings-badge {
  position: fixed;
  bottom: 24px;
  left: 24px;
  background: var(--gradient-primary);
  color: #fff;
  padding: 14px 22px;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg), var(--shadow-glow);
  z-index: 100;
  opacity: 0;
  transform: translateY(20px) scale(0.9);
  transition: all 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);
  pointer-events: none;
  text-align: center;
}

.savings-badge.visible {
  opacity: 1;
  transform: translateY(0) scale(1);
  pointer-events: auto;
}

.savings-badge .savings-number {
  font-size: 1.8rem;
  font-weight: 800;
  font-family: var(--font-mono);
  display: block;
  line-height: 1;
}

.savings-badge .savings-label {
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 1px;
  opacity: 0.8;
}

/* ─── Cost Comparison ─── */
.recommendation-highlight {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin-bottom: 18px;
}

.rec-card {
  padding: 16px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  text-align: center;
}

.rec-best {
  background: rgba(34,197,94,0.06);
  border-color: rgba(34,197,94,0.2);
}

.rec-value {
  background: rgba(0,212,255,0.06);
  border-color: rgba(0,212,255,0.2);
}

.rec-label {
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.8px;
  color: var(--text-muted);
  margin-bottom: 6px;
}

.rec-model {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-primary);
}

.rec-provider {
  font-size: 0.78rem;
  color: var(--text-secondary);
  margin-bottom: 6px;
}

.rec-cost {
  font-size: 1.3rem;
  font-weight: 700;
  font-family: var(--font-mono);
  color: var(--accent-green);
}

.rec-detail {
  font-size: 0.72rem;
  color: var(--text-muted);
  margin-top: 4px;
}

/* ─── Cost Table ─── */
.cost-table-wrap {
  overflow-x: auto;
}

.cost-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.78rem;
}

.cost-table th {
  text-align: left;
  padding: 8px 10px;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  font-size: 0.68rem;
  letter-spacing: 0.5px;
  border-bottom: 1px solid var(--border);
}

.cost-table td {
  padding: 8px 10px;
  border-bottom: 1px solid rgba(255,255,255,0.02);
  color: var(--text-secondary);
}

.cost-table tbody tr:hover {
  background: var(--bg-glass);
}

.cost-table .cost-total {
  font-family: var(--font-mono);
  font-weight: 600;
  color: var(--text-primary);
}

.provider-badge {
  font-size: 0.7rem;
  padding: 2px 8px;
  border-radius: 10px;
  font-weight: 500;
  display: inline-block;
}

.type-badge {
  font-size: 0.72rem;
  color: var(--text-muted);
}

.savings-cell {
  font-family: var(--font-mono);
  color: var(--accent-green);
  font-weight: 500;
}

/* ─── Model Grid ─── */
.models-section {
  margin-bottom: 40px;
}

.section-title {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 20px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.section-title::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--border);
}

.provider-section {
  margin-bottom: 24px;
}

.provider-name {
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 10px;
}

.model-cards {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 10px;
}

.model-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 14px;
  transition: var(--transition);
}

.model-card:hover {
  border-color: var(--border-active);
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}

.model-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 10px;
}

.model-card-name {
  font-weight: 600;
  font-size: 0.85rem;
}

.model-card-type {
  font-size: 0.7rem;
  color: var(--text-muted);
}

.price-row {
  display: flex;
  justify-content: space-between;
  font-size: 0.78rem;
  padding: 2px 0;
  color: var(--text-secondary);
}

.price-row span:last-child {
  font-family: var(--font-mono);
  color: var(--text-primary);
}

.model-card-ctx {
  margin-top: 8px;
  font-size: 0.72rem;
  color: var(--text-muted);
}

.model-card-note {
  margin-top: 6px;
  font-size: 0.68rem;
  color: var(--accent-amber);
  font-style: italic;
}

/* ─── Style Guide ─── */
.guide-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 18px;
}

.guide-header h3 {
  font-size: 1rem;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.guide-version {
  font-size: 0.72rem;
  font-family: var(--font-mono);
  color: var(--text-muted);
  background: var(--bg-glass);
  padding: 2px 8px;
  border-radius: 10px;
  border: 1px solid var(--border);
}

.guide-category {
  margin-bottom: 18px;
}

.guide-category h4 {
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--accent);
  margin-bottom: 8px;
}

.guide-category ul {
  list-style: none;
  padding: 0;
}

.guide-category li {
  padding: 6px 0 6px 16px;
  position: relative;
  font-size: 0.82rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

.guide-category li::before {
  content: '→';
  position: absolute;
  left: 0;
  color: var(--accent);
}

/* ─── Toast ─── */
#toast {
  position: fixed;
  bottom: 30px;
  left: 50%;
  transform: translateX(-50%) translateY(20px);
  background: var(--bg-card);
  color: var(--text-primary);
  padding: 12px 24px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-lg);
  font-size: 0.85rem;
  opacity: 0;
  transition: all 0.3s ease;
  z-index: 200;
  pointer-events: none;
  backdrop-filter: blur(20px);
}

#toast.visible {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

/* ─── Footer ─── */
.app-footer {
  text-align: center;
  padding: 24px 0;
  border-top: 1px solid var(--border);
  margin-top: 40px;
}

.app-footer p {
  font-size: 0.78rem;
  color: var(--text-muted);
}

.app-footer a {
  color: var(--accent);
  text-decoration: none;
}

.app-footer a:hover {
  text-decoration: underline;
}

/* ─── Responsive ─── */
@media (max-width: 1024px) {
  .main-grid { grid-template-columns: 1fr; }
  #prompt-input { min-height: 250px; }
  .stats-bar { grid-template-columns: repeat(2, 1fr); }
  .recommendation-highlight { grid-template-columns: 1fr; }
}

@media (max-width: 640px) {
  .app-header { flex-direction: column; gap: 12px; }
  .stats-bar { grid-template-columns: 1fr 1fr; }
  .model-cards { grid-template-columns: 1fr; }
  .tabs { flex-wrap: wrap; }
  html { font-size: 14px; }
}

/* ─── Animations ─── */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

.stat-card,
.change-group,
.suggestion-card,
.model-card {
  animation: fadeIn 0.3s ease forwards;
}