:root {
  --bg: #f4f6f8;
  --panel: #ffffff;
  --panel-2: #f8fafc;
  --text: #111827;
  --muted: #667085;
  --border: #e4e7ec;
  --accent: #2563eb;
  --accent-2: #1d4ed8;
  --danger: #dc2626;
  --shadow: 0 8px 28px rgba(16, 24, 40, 0.07);
  --radius: 18px;
}

:root[data-theme="dark"] {
  --bg: #0d1117;
  --panel: #161b22;
  --panel-2: #0f141b;
  --text: #e6edf3;
  --muted: #9aa4b2;
  --border: #30363d;
  --accent: #4f8cff;
  --accent-2: #76a7ff;
  --danger: #ff6b6b;
  --shadow: 0 10px 36px rgba(0, 0, 0, 0.22);
}

* { box-sizing: border-box; }
html { font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; }
body { margin: 0; background: var(--bg); color: var(--text); }
button, input, select { font: inherit; }
button { cursor: pointer; }

.topbar {
  min-height: 78px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 16px max(20px, calc((100vw - 1320px) / 2));
  border-bottom: 1px solid var(--border);
  background: color-mix(in srgb, var(--panel) 94%, transparent);
  backdrop-filter: blur(12px);
  position: sticky;
  top: 0;
  z-index: 20;
}
.topbar h1 { margin: 0; font-size: 24px; letter-spacing: -0.03em; }
.topbar p { margin: 2px 0 0; color: var(--muted); font-size: 13px; }
.top-actions { display: flex; align-items: center; gap: 10px; }
.compact-field { display: flex; align-items: center; gap: 8px; color: var(--muted); font-size: 13px; }
.compact-field select { width: 86px; }

.app-shell { width: min(1320px, calc(100% - 32px)); margin: 28px auto 40px; display: grid; gap: 18px; }
.panel { background: var(--panel); border: 1px solid var(--border); border-radius: var(--radius); box-shadow: var(--shadow); padding: 22px; }
.section-heading { margin-bottom: 18px; }
.section-heading h2, .optimizer-copy h2 { margin: 0; font-size: 18px; letter-spacing: -0.02em; }
.section-heading p, .optimizer-copy p { margin: 5px 0 0; color: var(--muted); font-size: 13px; }
.split-heading { display: flex; align-items: center; justify-content: space-between; gap: 16px; }

.grid { display: grid; gap: 14px; }
.stock-grid { grid-template-columns: repeat(3, minmax(0, 1fr)) 190px; align-items: end; }
.trim-grid { grid-template-columns: repeat(4, minmax(0, 1fr)); margin-top: 12px; }
label > span { display: block; font-size: 12px; color: var(--muted); margin-bottom: 7px; font-weight: 600; }
.unit-label { font-weight: 500; color: var(--muted); }
input[type="number"], input[type="text"], select {
  width: 100%; height: 42px; padding: 0 11px; border: 1px solid var(--border); border-radius: 10px;
  background: var(--panel-2); color: var(--text); outline: none; transition: .15s ease;
}
input:focus, select:focus { border-color: var(--accent); box-shadow: 0 0 0 3px color-mix(in srgb, var(--accent) 16%, transparent); }

.advanced { margin-top: 14px; border-top: 1px solid var(--border); padding-top: 14px; }
.advanced summary { cursor: pointer; color: var(--muted); font-size: 13px; font-weight: 650; }

.switch-label { display: flex; align-items: center; justify-content: space-between; gap: 14px; height: 42px; padding: 0 12px; border: 1px solid var(--border); border-radius: 10px; background: var(--panel-2); }
.switch-label > span { margin: 0; }
.switch-label input { display: none; }
.switch-label i { width: 36px; height: 20px; border-radius: 999px; background: #98a2b3; position: relative; flex: 0 0 auto; transition: .2s; }
.switch-label i::after { content: ""; width: 16px; height: 16px; background: white; border-radius: 50%; position: absolute; top: 2px; left: 2px; transition: .2s; box-shadow: 0 1px 4px rgba(0,0,0,.2); }
.switch-label input:checked + i { background: var(--accent); }
.switch-label input:checked + i::after { transform: translateX(16px); }
.switch-label.small { width: 190px; }

.table-wrap { overflow-x: auto; border: 1px solid var(--border); border-radius: 12px; }
table { border-collapse: collapse; width: 100%; min-width: 760px; }
th, td { padding: 10px; border-bottom: 1px solid var(--border); text-align: left; font-size: 13px; }
th { color: var(--muted); font-size: 11px; text-transform: uppercase; letter-spacing: .04em; background: var(--panel-2); }
tbody tr:last-child td { border-bottom: 0; }
td input[type="number"], td input[type="text"] { height: 36px; }
.row-check { display: flex; align-items: center; gap: 6px; color: var(--muted); }
.row-check input { width: 18px; height: 18px; accent-color: var(--accent); }
.remove-btn { width: 34px; height: 34px; border: 0; border-radius: 8px; background: transparent; color: var(--muted); font-size: 18px; }
.remove-btn:hover { background: color-mix(in srgb, var(--danger) 10%, transparent); color: var(--danger); }

button { border: 1px solid transparent; border-radius: 10px; height: 40px; padding: 0 14px; transition: .15s ease; }
.primary-btn { background: var(--accent); color: white; font-weight: 700; min-width: 150px; }
.primary-btn:hover { background: var(--accent-2); transform: translateY(-1px); }
.secondary-btn { background: var(--panel-2); border-color: var(--border); color: var(--text); font-weight: 650; }
.secondary-btn:hover { border-color: var(--accent); }
.ghost-btn { background: transparent; color: var(--muted); border-color: var(--border); }
.ghost-btn.danger:hover { color: var(--danger); border-color: var(--danger); }
.icon-btn { width: 40px; padding: 0; border-color: var(--border); background: var(--panel-2); color: var(--text); }
button:disabled { opacity: .45; cursor: not-allowed; transform: none !important; }

.preset-row { display: flex; gap: 8px; margin-top: 12px; }
.action-panel { display: flex; align-items: center; justify-content: space-between; gap: 20px; }
.action-buttons { display: flex; align-items: center; gap: 10px; }

.notice { border-radius: 12px; padding: 14px 16px; border: 1px solid; font-size: 13px; }
.notice.error { color: #b42318; background: #fef3f2; border-color: #fecdca; }
:root[data-theme="dark"] .notice.error { color: #ffb4ab; background: #2a1515; border-color: #5f2b2b; }
.hidden { display: none !important; }

.summary-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 12px; }
.metric { background: var(--panel); border: 1px solid var(--border); border-radius: 14px; padding: 16px 18px; box-shadow: var(--shadow); }
.metric span { color: var(--muted); font-size: 12px; }
.metric strong { display: block; margin-top: 5px; font-size: 25px; letter-spacing: -0.04em; }

.export-actions { display: flex; gap: 8px; }
.layouts { display: grid; gap: 22px; }
.layouts.empty-state { min-height: 220px; place-items: center; text-align: center; color: var(--muted); }
.layouts.empty-state strong { display: block; color: var(--text); margin-bottom: 5px; }
.sheet-card { border: 1px solid var(--border); border-radius: 14px; overflow: hidden; background: var(--panel-2); }
.sheet-head { display: flex; align-items: center; justify-content: space-between; gap: 12px; padding: 12px 14px; border-bottom: 1px solid var(--border); }
.sheet-head strong { font-size: 14px; }
.sheet-head span { color: var(--muted); font-size: 12px; }
.sheet-stage { padding: 14px; overflow: auto; background-image: linear-gradient(to right, color-mix(in srgb, var(--border) 35%, transparent) 1px, transparent 1px), linear-gradient(to bottom, color-mix(in srgb, var(--border) 35%, transparent) 1px, transparent 1px); background-size: 16px 16px; }
.sheet-svg { display: block; max-width: 100%; height: auto; margin: 0 auto; background: #fff; box-shadow: 0 2px 9px rgba(16,24,40,.12); }
.sheet-svg .stock { fill: #f8fafc; stroke: #344054; stroke-width: 2; }
.sheet-svg .usable { fill: none; stroke: #98a2b3; stroke-width: 1.5; stroke-dasharray: 7 5; }
.sheet-svg .part { stroke: rgba(17,24,39,.5); stroke-width: 1.2; }
.sheet-svg .part-label { font-family: ui-sans-serif, system-ui, sans-serif; fill: #111827; font-weight: 700; text-anchor: middle; dominant-baseline: middle; pointer-events: none; }
.sheet-svg .part-dim { font-family: ui-sans-serif, system-ui, sans-serif; fill: #344054; text-anchor: middle; dominant-baseline: middle; pointer-events: none; }
.legend { display: flex; flex-wrap: wrap; gap: 8px 14px; padding: 10px 14px 14px; }
.legend-item { display: inline-flex; align-items: center; gap: 6px; font-size: 11px; color: var(--muted); }
.legend-swatch { width: 11px; height: 11px; border-radius: 3px; border: 1px solid rgba(0,0,0,.16); }

footer { width: min(1320px, calc(100% - 32px)); margin: 0 auto 30px; display: flex; justify-content: space-between; gap: 20px; color: var(--muted); font-size: 12px; }
footer a { color: inherit; }

@media (max-width: 980px) {
  .stock-grid { grid-template-columns: repeat(2, minmax(0,1fr)); }
  .summary-grid { grid-template-columns: repeat(2,1fr); }
}
@media (max-width: 680px) {
  .topbar { position: static; }
  .topbar p { display: none; }
  .app-shell { width: min(100% - 20px, 1320px); margin-top: 12px; }
  .panel { padding: 16px; border-radius: 14px; }
  .stock-grid, .trim-grid, .summary-grid { grid-template-columns: 1fr; }
  .split-heading, .action-panel { align-items: stretch; flex-direction: column; }
  .action-buttons { flex-direction: column; align-items: stretch; }
  .switch-label.small { width: 100%; }
  .primary-btn { width: 100%; }
  .export-actions { display: grid; grid-template-columns: repeat(3,1fr); }
  .top-actions .compact-field span { display: none; }
}

@media print {
  .topbar, .settings-panel, .parts-panel, .action-panel, .export-actions, footer { display: none !important; }
  body { background: white; }
  .app-shell { width: 100%; margin: 0; }
  .panel, .metric { box-shadow: none; border-color: #ddd; }
  .summary-grid { grid-template-columns: repeat(4,1fr); }
  .sheet-card { break-inside: avoid; }
}