:root {
  --text: #31333F;
  --muted: #6B6E7A;
  --border: #D6D8DE;
  --field: #F0F2F6;
  --primary: #FF4B4B;
  --accent: #C2410C;
  --blue: #2563EB;
  font-family: "Source Sans Pro", "Segoe UI", system-ui, sans-serif;
  color: var(--text);
}

* { box-sizing: border-box; }
body { margin: 0; background: #FFFFFF; }
.page { max-width: 1480px; margin: 0 auto; padding: 24px 48px 64px; }
.hidden { display: none !important; }

h1 { font-size: 2.6rem; margin: 0; }
h2 { font-size: 1.6rem; margin: 28px 0 12px; }
h3 { font-size: 1rem; margin: 18px 0 8px; }
.card h2 { margin-top: 0; }
.caption { color: var(--muted); font-size: 0.85rem; margin: 4px 0 12px; }

.title-row { display: flex; justify-content: space-between; align-items: flex-end; gap: 16px; margin-bottom: 16px; }
.tabs { display: flex; gap: 24px; border-bottom: 1px solid var(--border); margin-bottom: 16px; }
.tab { background: none; border: none; padding: 8px 0; font: inherit; font-size: 0.95rem; cursor: pointer;
  color: var(--text); border-bottom: 2px solid transparent; }
.tab.active { color: var(--primary); border-bottom-color: var(--primary); }

.card { border: 1px solid var(--border); border-radius: 8px; padding: 20px; }

label { display: block; font-size: 0.875rem; margin: 8px 0 4px; }
.accent-label { color: var(--accent); font-weight: 600; }
input[type="number"], select {
  width: 100%; font: inherit; font-size: 0.95rem; padding: 8px 10px; border: 1px solid transparent;
  border-radius: 8px; background: var(--field); color: var(--text);
}
input[type="number"]:focus, select:focus { outline: none; border-color: var(--primary); }
input.invalid, select.invalid { border-color: var(--primary); }
.help { display: inline-block; width: 16px; height: 16px; line-height: 14px; text-align: center;
  border: 1px solid var(--muted); border-radius: 50%; font-size: 0.7rem; color: var(--muted); cursor: help; }

.slider-row { display: flex; align-items: center; gap: 10px; margin-top: 8px; }
.slider-row input { flex: 1; accent-color: var(--primary); }
.slider-row output { font-size: 0.85rem; color: var(--primary); min-width: 3em; text-align: right; }

.distribution { display: grid; grid-template-columns: minmax(220px, 1fr) 2.4fr; gap: 32px; }
.distribution-graph img { width: 100%; height: auto; display: block; }
.metrics { display: grid; grid-template-columns: repeat(4, 1fr); gap: 12px; margin-top: 8px; }
.metric-label { display: block; font-size: 0.85rem; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.metric-value { display: block; font-size: 2rem; }

.sheet { display: grid; grid-template-columns: 1.2fr 1fr 2fr; gap: 32px; }
.pair { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.triple { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; }

.frequency-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px 24px; }
.frequency-row { display: flex; align-items: center; gap: 10px; }
.frequency-select { flex: 1; min-width: 0; }
.icon { border: 1px solid #DDDDDD; border-radius: 6px; flex: none; }

.generate-row { display: flex; flex-wrap: wrap; align-items: flex-end; gap: 16px; }
.narrow { width: 180px; }
.check { display: flex; align-items: center; gap: 8px; margin: 0; height: 40px; font-size: 0.95rem; }
.check input { accent-color: var(--primary); width: 18px; height: 18px; }

.button { display: inline-flex; align-items: center; gap: 6px; font: inherit; font-size: 0.95rem;
  padding: 8px 14px; min-height: 40px; border: 1px solid var(--border); border-radius: 8px;
  background: #FFFFFF; color: var(--text); cursor: pointer; text-decoration: none; }
.button:hover { border-color: var(--primary); color: var(--primary); }
.button.primary { background: var(--primary); border-color: var(--primary); color: #FFFFFF; }
.button.primary:hover { background: #E03E3E; color: #FFFFFF; }
.button:disabled { opacity: 0.45; cursor: not-allowed; }

.message { padding: 12px 16px; border-radius: 8px; font-size: 0.95rem; margin: 8px 0; }
.message.error { background: #FFECEC; color: #7D1F1F; }
.message.warning { background: #FFF8E1; color: #6B4E00; }
.message.info { background: #E8F1FB; color: #1E4C80; }
.message.success { background: #E8F7EE; color: #17643A; }

.progress { margin: 12px 0; }
.progress-text { font-size: 0.9rem; margin-bottom: 6px; }
.progress-track { height: 6px; background: var(--field); border-radius: 3px; overflow: hidden; }
.progress-bar { height: 100%; width: 0; background: var(--primary); transition: width 0.3s; }

.batch { display: grid; grid-template-columns: 4fr 1.25fr; gap: 16px; margin-top: 16px; align-items: start; }
.thumbnails { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
.thumb { cursor: zoom-in; }
.thumb img { width: 100%; display: block; }
.thumb:hover img, .thumb:focus-visible img { outline: 3px solid var(--accent); outline-offset: -3px; }
.thumb .caption { margin-top: 6px; }
.thumb.pending { border: 1px dashed var(--border); aspect-ratio: 30 / 22; display: flex; align-items: center;
  justify-content: center; color: var(--muted); font-size: 0.85rem; cursor: default; }
.batch-info ul { padding-left: 18px; margin: 8px 0; font-size: 0.9rem; }

table.data { border-collapse: collapse; font-size: 0.85rem; width: 100%; margin: 8px 0; }
table.data th, table.data td { border: 1px solid #E6E8EC; padding: 5px 8px; text-align: left; }
table.data th { background: #F7F8FA; font-weight: 600; }
table.density { width: auto; }
table.density td { text-align: right; min-width: 3.2em; }

.wide-image { width: 100%; }

dialog { width: min(1100px, 94vw); max-height: 94vh; border: none; border-radius: 10px; padding: 24px 28px;
  box-shadow: 0 8px 40px rgba(0, 0, 0, 0.25); }
dialog::backdrop { background: rgba(30, 32, 40, 0.45); }
.dialog-head { display: flex; justify-content: space-between; align-items: center; }
.dialog-head h2 { margin: 0; }
.close { background: none; border: none; font-size: 1.8rem; cursor: pointer; color: var(--text); line-height: 1; }
.downloads { display: flex; flex-wrap: wrap; gap: 8px; margin: 12px 0; }
.viewer-image { position: relative; }
.viewer-image img { width: 100%; display: block; border: 1px solid #E6E8EC; }
.step { position: absolute; top: 50%; transform: translateY(-50%); width: 48px; height: 48px; border-radius: 50%;
  border: 2px solid var(--blue); background: rgba(255, 255, 255, 0.25); color: var(--blue); font-size: 2rem;
  line-height: 1; padding: 0 0 4px; cursor: pointer; }
.step:hover { background: rgba(37, 99, 235, 0.12); border-color: #1D4ED8; color: #1D4ED8; }
.step.prev { left: 12px; }
.step.next { right: 12px; }
.viewer-stats { display: grid; grid-template-columns: 1.8fr 1fr; gap: 32px; }
.viewer-stats ul { padding-left: 18px; font-size: 0.9rem; }
details { margin: 8px 0; border: 1px solid var(--border); border-radius: 8px; padding: 8px 12px; }
summary { cursor: pointer; font-size: 0.95rem; }
pre { white-space: pre; overflow-x: auto; background: var(--field); padding: 12px; border-radius: 6px; font-size: 0.8rem; }

@media (max-width: 800px) {
  .page { padding: 16px; }
  .distribution, .sheet, .batch, .viewer-stats { grid-template-columns: 1fr; }
  .frequency-grid, .thumbnails { grid-template-columns: repeat(2, 1fr); }
  .metrics { grid-template-columns: repeat(2, 1fr); }
}