/* ═══════════════════════════════════════════════════
   InvoiceDiff — Design System
   ═══════════════════════════════════════════════════ */

/* ── Tokens ── */
:root {
  /* Surface palette */
  --bg-base: #0b0f1a;
  --bg-surface: #111827;
  --bg-elevated: #1e293b;
  --bg-glass: rgba(30, 41, 59, .55);
  --border-subtle: rgba(148, 163, 184, .12);
  --border-focus: rgba(99, 102, 241, .6);

  /* Text */
  --text-primary: #f1f5f9;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;

  /* Accent */
  --accent: #818cf8;
  --accent-glow: rgba(129, 140, 248, .25);

  /* Diff colours */
  --diff-added-bg: rgba(34, 197, 94, .12);
  --diff-added-border: rgba(34, 197, 94, .30);
  --diff-added-text: #4ade80;

  --diff-removed-bg: rgba(239, 68, 68, .12);
  --diff-removed-border: rgba(239, 68, 68, .30);
  --diff-removed-text: #f87171;

  --diff-modified-bg: rgba(251, 191, 36, .10);
  --diff-modified-border: rgba(251, 191, 36, .28);
  --diff-modified-text: #fbbf24;

  --diff-unchanged-bg: transparent;

  /* Sizing */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;

  --font-family: 'Inter', system-ui, -apple-system, sans-serif;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

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

/* ── Background Particles ── */
.bg-particles {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  overflow: hidden;
}

.particle {
  position: absolute;
  border-radius: 50%;
  opacity: .15;
  filter: blur(80px);
  animation: float 20s ease-in-out infinite;
}

.p1 {
  width: 500px;
  height: 500px;
  background: #818cf8;
  top: -10%;
  left: -5%;
  animation-delay: 0s;
}

.p2 {
  width: 400px;
  height: 400px;
  background: #f472b6;
  top: 40%;
  right: -8%;
  animation-delay: -5s;
}

.p3 {
  width: 350px;
  height: 350px;
  background: #34d399;
  bottom: -8%;
  left: 25%;
  animation-delay: -10s;
}

.p4 {
  width: 300px;
  height: 300px;
  background: #fbbf24;
  top: 20%;
  left: 50%;
  animation-delay: -15s;
}

.p5 {
  width: 250px;
  height: 250px;
  background: #60a5fa;
  bottom: 15%;
  right: 20%;
  animation-delay: -8s;
}

@keyframes float {

  0%,
  100% {
    transform: translate(0, 0) scale(1);
  }

  33% {
    transform: translate(30px, -20px) scale(1.05);
  }

  66% {
    transform: translate(-20px, 15px) scale(.95);
  }
}

/* ── Layout helpers ── */
main {
  position: relative;
  z-index: 1;
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 24px 60px;
}

.hidden {
  display: none !important;
}

/* ═══════════════════════════════
   Header
   ═══════════════════════════════ */
.site-header {
  position: relative;
  z-index: 1;
  text-align: center;
  padding: 48px 24px 32px;
}

.logo {
  display: inline-flex;
  align-items: center;
  gap: 12px;
}

.logo-icon {
  width: 36px;
  height: 36px;
  color: var(--accent);
}

.logo h1 {
  font-size: 1.75rem;
  font-weight: 800;
  letter-spacing: -.02em;
  color: var(--text-primary);
}

.logo .accent {
  color: var(--accent);
}

.tagline {
  margin-top: 8px;
  color: var(--text-secondary);
  font-size: .95rem;
  font-weight: 400;
}

/* ═══════════════════════════════
   Upload Section
   ═══════════════════════════════ */
.upload-section {
  padding-top: 16px;
}

.upload-grid {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: 24px;
  align-items: center;
}

.upload-card {
  background: var(--bg-glass);
  backdrop-filter: blur(24px);
  -webkit-backdrop-filter: blur(24px);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 24px;
  transition: border-color .25s, box-shadow .25s;
}

.upload-card:hover,
.upload-card.has-file {
  border-color: var(--border-focus);
  box-shadow: 0 0 0 3px var(--accent-glow);
}

.upload-dropzone {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 200px;
  border: 2px dashed var(--border-subtle);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: border-color .2s, background .2s;
}

.upload-dropzone.dragover,
.upload-dropzone:focus-visible {
  border-color: var(--accent);
  background: var(--accent-glow);
  outline: none;
}

.dropzone-inner {
  text-align: center;
  padding: 24px;
}

.upload-icon {
  width: 48px;
  height: 48px;
  color: var(--text-muted);
  margin-bottom: 12px;
  transition: color .2s, transform .2s;
}

.upload-dropzone:hover .upload-icon {
  color: var(--accent);
  transform: translateY(-4px);
}

.dropzone-label {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 4px;
}

.dropzone-hint {
  font-size: .8rem;
  color: var(--text-muted);
}

.upload-divider {
  display: flex;
  align-items: center;
  justify-content: center;
}

.upload-divider span {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--bg-elevated);
  border: 1px solid var(--border-subtle);
  font-weight: 700;
  font-size: .85rem;
  color: var(--accent);
  letter-spacing: .05em;
}

.file-info {
  margin-top: 12px;
  font-size: .82rem;
  color: var(--text-secondary);
  min-height: 22px;
  display: flex;
  align-items: center;
  gap: 6px;
}

.file-info .file-name {
  font-weight: 600;
  color: var(--accent);
}

.file-info .file-rows {
  color: var(--text-muted);
}

/* ── Compare Button ── */
.compare-actions {
  display: flex;
  justify-content: center;
  margin-top: 32px;
}

.btn-compare {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 14px 40px;
  border: none;
  border-radius: var(--radius-xl);
  background: linear-gradient(135deg, #818cf8 0%, #6366f1 100%);
  color: #fff;
  font-family: var(--font-family);
  font-size: 1rem;
  font-weight: 700;
  cursor: pointer;
  transition: transform .2s, box-shadow .2s, opacity .2s;
  box-shadow: 0 4px 24px rgba(99, 102, 241, .35);
}

.btn-compare:hover:not(:disabled) {
  transform: translateY(-2px);
  box-shadow: 0 8px 32px rgba(99, 102, 241, .5);
}

.btn-compare:active:not(:disabled) {
  transform: translateY(0);
}

.btn-compare:disabled {
  opacity: .35;
  cursor: not-allowed;
}

.btn-icon {
  width: 18px;
  height: 18px;
}

/* ═══════════════════════════════
   Results Section
   ═══════════════════════════════ */
.results-section {
  animation: fadeUp .5s ease;
}

@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ── Summary Bar ── */
.summary-bar {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 16px;
  margin-bottom: 24px;
}

.summary-card {
  background: var(--bg-glass);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 20px 16px;
  text-align: center;
  transition: transform .2s, border-color .2s;
}

.summary-card:hover {
  transform: translateY(-3px);
}

.summary-value {
  display: block;
  font-size: 2rem;
  font-weight: 800;
  line-height: 1;
  margin-bottom: 6px;
}

.summary-label {
  font-size: .78rem;
  font-weight: 500;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: .04em;
}

.summary-total .summary-value {
  color: var(--text-primary);
}

.summary-unchanged .summary-value {
  color: var(--text-secondary);
}

.summary-modified .summary-value {
  color: var(--diff-modified-text);
}

.summary-modified {
  border-color: var(--diff-modified-border);
}

.summary-added .summary-value {
  color: var(--diff-added-text);
}

.summary-added {
  border-color: var(--diff-added-border);
}

.summary-removed .summary-value {
  color: var(--diff-removed-text);
}

.summary-removed {
  border-color: var(--diff-removed-border);
}

/* ── Filter Bar ── */
.filter-bar {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 12px;
  flex-wrap: wrap;
}

.filter-label {
  font-size: .82rem;
  font-weight: 600;
  color: var(--text-muted);
  margin-right: 4px;
}

.filter-btn {
  padding: 6px 16px;
  border: 1px solid var(--border-subtle);
  border-radius: 999px;
  background: transparent;
  color: var(--text-secondary);
  font-family: var(--font-family);
  font-size: .8rem;
  font-weight: 600;
  cursor: pointer;
  transition: all .2s;
}

.filter-btn:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.filter-btn.active {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

.filter-spacer {
  flex: 1;
}

.search-box {
  position: relative;
}

.search-icon {
  position: absolute;
  left: 12px;
  top: 50%;
  transform: translateY(-50%);
  width: 16px;
  height: 16px;
  color: var(--text-muted);
  pointer-events: none;
}

.search-box input {
  padding: 7px 14px 7px 36px;
  border: 1px solid var(--border-subtle);
  border-radius: 999px;
  background: var(--bg-elevated);
  color: var(--text-primary);
  font-family: var(--font-family);
  font-size: .82rem;
  width: 220px;
  transition: border-color .2s, width .3s;
}

.search-box input:focus {
  outline: none;
  border-color: var(--accent);
  width: 280px;
}

.search-box input::placeholder {
  color: var(--text-muted);
}

/* ── Key Column Selector ── */
.key-column-bar {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
  padding: 10px 16px;
  background: var(--bg-glass);
  backdrop-filter: blur(16px);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
}

.key-column-label {
  font-size: .82rem;
  font-weight: 600;
  color: var(--text-secondary);
  white-space: nowrap;
}

.key-column-select {
  padding: 6px 12px;
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  background: var(--bg-elevated);
  color: var(--text-primary);
  font-family: var(--font-family);
  font-size: .82rem;
  cursor: pointer;
}

.key-column-select:focus {
  outline: none;
  border-color: var(--accent);
}

.btn-recompare {
  padding: 6px 18px;
  border: 1px solid var(--accent);
  border-radius: 999px;
  background: transparent;
  color: var(--accent);
  font-family: var(--font-family);
  font-size: .78rem;
  font-weight: 600;
  cursor: pointer;
  transition: all .2s;
}

.btn-recompare:hover {
  background: var(--accent);
  color: #fff;
}

/* ── Diff Table ── */
.table-wrapper {
  overflow-x: auto;
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  background: var(--bg-glass);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
}

.diff-table {
  width: 100%;
  border-collapse: collapse;
  font-size: .82rem;
}

.diff-table th,
.diff-table td {
  padding: 10px 14px;
  text-align: left;
  border-bottom: 1px solid var(--border-subtle);
  white-space: nowrap;
}

.diff-table th {
  position: sticky;
  top: 0;
  background: var(--bg-elevated);
  font-weight: 700;
  font-size: .75rem;
  text-transform: uppercase;
  letter-spacing: .04em;
  color: var(--text-muted);
  z-index: 2;
}

.diff-table tbody tr {
  transition: background .15s;
}

.diff-table tbody tr:hover {
  background: rgba(148, 163, 184, .06);
}

/* Row status indicator */
.diff-table .row-status {
  width: 10px;
  padding-left: 8px;
  padding-right: 4px;
}

.status-dot {
  display: inline-block;
  width: 8px;
  height: 8px;
  border-radius: 50%;
}

.status-dot.unchanged {
  background: var(--text-muted);
  opacity: .4;
}

.status-dot.modified {
  background: var(--diff-modified-text);
  box-shadow: 0 0 6px var(--diff-modified-text);
}

.status-dot.added {
  background: var(--diff-added-text);
  box-shadow: 0 0 6px var(--diff-added-text);
}

.status-dot.removed {
  background: var(--diff-removed-text);
  box-shadow: 0 0 6px var(--diff-removed-text);
}

/* Row diff backgrounds */
.diff-table tr.row-modified {
  background: var(--diff-modified-bg);
}

.diff-table tr.row-added {
  background: var(--diff-added-bg);
}

.diff-table tr.row-removed {
  background: var(--diff-removed-bg);
}

/* Cell-level diff highlight */
.diff-table td.cell-changed {
  position: relative;
}

.cell-old {
  color: var(--diff-removed-text);
  text-decoration: line-through;
  opacity: .7;
  margin-right: 6px;
}

.cell-new {
  color: var(--diff-added-text);
  font-weight: 600;
}

.cell-arrow {
  color: var(--text-muted);
  margin: 0 4px;
  font-size: .7rem;
}

/* ── Company Header Rows ── */
.company-header-row {
  background: linear-gradient(90deg, rgba(99, 102, 241, .12) 0%, rgba(30, 41, 59, .6) 100%) !important;
  border-top: 2px solid rgba(99, 102, 241, .25);
}

.company-header-row td {
  padding: 14px 14px 10px !important;
  border-bottom: 1px solid rgba(99, 102, 241, .15) !important;
}

.company-name-cell {
  font-size: .88rem;
  letter-spacing: -.01em;
  color: var(--text-primary);
}

.company-name-cell strong {
  font-weight: 700;
}

.company-sku-count {
  display: inline-block;
  margin-left: 12px;
  font-size: .72rem;
  font-weight: 500;
  color: var(--text-muted);
  background: var(--bg-elevated);
  padding: 2px 10px;
  border-radius: 999px;
  vertical-align: middle;
}

/* ── SKU Row Status Labels ── */
.status-label {
  font-size: .72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .05em;
  padding: 2px 8px;
  border-radius: 4px;
}

.status-unchanged {
  color: var(--text-muted);
}

.status-modified {
  color: var(--diff-modified-text);
  background: var(--diff-modified-bg);
}

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

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

/* ── Diff positive / negative ── */
.diff-positive {
  color: var(--diff-added-text);
}

.diff-negative {
  color: var(--diff-removed-text);
}

/* ── Changed Value Cell ── */
.cell-changed-val {
  background: rgba(251, 191, 36, .08);
  font-weight: 600;
  color: var(--diff-modified-text) !important;
}

/* ── SKU & Description Cells ── */
.sku-cell {
  font-family: 'Courier New', monospace;
  font-size: .76rem;
  letter-spacing: .02em;
  color: var(--text-secondary);
}

.desc-cell {
  max-width: 320px;
  white-space: normal !important;
  word-break: break-word;
  font-size: .78rem;
  color: var(--text-secondary);
  line-height: 1.4;
}

/* ── Action Buttons ── */
.back-actions {
  display: flex;
  justify-content: center;
  gap: 16px;
  margin-top: 32px;
}

.btn-back {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 28px;
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-xl);
  background: transparent;
  color: var(--text-secondary);
  font-family: var(--font-family);
  font-size: .88rem;
  font-weight: 600;
  cursor: pointer;
  transition: all .2s;
}

.btn-back:hover {
  border-color: var(--accent);
  color: var(--accent);
}

/* ── Export Button ── */
.btn-export {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 28px;
  border: none;
  border-radius: var(--radius-xl);
  background: linear-gradient(135deg, #22c55e 0%, #16a34a 100%);
  color: #fff;
  font-family: var(--font-family);
  font-size: .88rem;
  font-weight: 700;
  cursor: pointer;
  transition: transform .2s, box-shadow .2s;
  box-shadow: 0 4px 20px rgba(34, 197, 94, .3);
}

.btn-export:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 28px rgba(34, 197, 94, .45);
}

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

/* ═══════════════════════════════
   Footer
   ═══════════════════════════════ */
.site-footer {
  position: relative;
  z-index: 1;
  text-align: center;
  padding: 40px 24px 32px;
  color: var(--text-muted);
  font-size: .78rem;
}

/* ═══════════════════════════════
   Responsive
   ═══════════════════════════════ */
@media (max-width: 900px) {
  .upload-grid {
    grid-template-columns: 1fr;
  }

  .upload-divider {
    justify-self: center;
  }

  .summary-bar {
    grid-template-columns: repeat(3, 1fr);
  }
}

@media (max-width: 600px) {
  .summary-bar {
    grid-template-columns: repeat(2, 1fr);
  }

  .filter-bar {
    gap: 6px;
  }

  .search-box input {
    width: 160px;
  }

  .search-box input:focus {
    width: 200px;
  }
}