:root {
  --bg: #f4f5f7; --fg: #16181d; --muted: #646a73; --line: #e2e4e9; --card: #fff; --soft: #eef2fb;
  --accent: #2a6fdb; --accent-fg: #fff; --gold: #ffd60a; --ok: #1f9d55; --err: #c62828; --shadow: 0 1px 2px rgba(16, 24, 40, .05), 0 4px 16px rgba(16, 24, 40, .06);
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) { --bg: #0f1115; --fg: #e9ebef; --muted: #9aa1ab; --line: #262a31; --card: #171a20; --soft: #1b2232; --accent: #6ea0ff; --accent-fg: #0b1220; --ok: #4cd97b; --err: #ff8a80; --shadow: none; }
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; background: var(--bg); color: var(--fg); font: 16px/1.55 Inter, system-ui, -apple-system, "Segoe UI", Roboto, sans-serif; }
.banner { background: var(--gold); color: #1d1d1b; text-align: center; padding: 8px 16px; font-size: .88rem; font-weight: 500; }
header.hero, main, footer { max-width: 1060px; margin: 0 auto; padding: 0 16px; }
header.hero { padding-top: 22px; padding-bottom: 6px; }
.brand { display: flex; align-items: center; gap: 14px; }
.brand img { flex: none; border-radius: 12px; }
h1 { font-size: 1.7rem; letter-spacing: -.01em; margin: 0; }
h2 { font-size: 1.2rem; margin: 0 0 6px; letter-spacing: -.005em; }
h2.inline { display: inline; }
h3 { font-size: 1rem; margin: 2px 0 8px; display: flex; align-items: center; gap: 8px; }
.sub { color: var(--muted); margin: 2px 0 0; }
.note { color: var(--muted); font-size: .9rem; margin: 4px 0; }
.why { margin: 12px 0 0; }
.why p { font-size: .95rem; margin: 8px 0; max-width: 75ch; }
summary { cursor: pointer; color: var(--muted); }
summary::marker { color: var(--accent); }
details { margin: 8px 0; }
.card { background: var(--card); border: 1px solid var(--line); border-radius: 14px; padding: 18px; margin: 16px 0; box-shadow: var(--shadow); }
.card > details > summary { color: var(--fg); }
.step { border-top: 1px solid var(--line); padding-top: 14px; margin-top: 14px; }
.n { display: inline-grid; place-items: center; min-width: 1.6em; height: 1.6em; border-radius: 50%; background: var(--accent); color: var(--accent-fg); font-size: .8em; font-weight: 700; }
.row { display: flex; flex-wrap: wrap; gap: 8px 12px; align-items: center; margin: 10px 0; }
button, .file { font: inherit; font-size: .95rem; padding: 8px 14px; border-radius: 9px; border: 1px solid var(--line); background: var(--card); color: var(--fg); cursor: pointer; display: inline-flex; align-items: center; gap: 6px; }
button:hover, .file:hover { border-color: var(--accent); }
button.primary, .file.primary { background: var(--accent); color: var(--accent-fg); border-color: var(--accent); font-weight: 600; }
button:disabled { opacity: .45; cursor: default; }
.file input { display: none; }
input[type=number], input[type=text], select { font: inherit; font-size: .95rem; padding: 6px 9px; border-radius: 8px; border: 1px solid var(--line); background: var(--card); color: var(--fg); }
input[type=number] { width: 6.5em; }
/* the setup guide */
.guide { display: grid; grid-template-columns: repeat(auto-fill, minmax(230px, 1fr)); gap: 14px; margin-top: 12px; }
.guide figure { margin: 0; background: var(--soft); border-radius: 12px; overflow: hidden; border: 1px solid var(--line); }
.guide svg { display: block; width: 100%; height: auto; }
.guide figcaption { padding: 10px 12px 12px; font-size: .88rem; }
.guide figcaption b { display: block; font-size: .95rem; margin-bottom: 2px; }
.guide .t { font: 600 10px system-ui, sans-serif; fill: #1d1d1b; }
.guide .t.g { fill: #1f7a3f; } .guide .t.r { fill: #b3261e; } .guide .t.b { fill: #2a6fdb; font-size: 14px; } .guide .t.w { fill: #fff; }
.slide { animation: slide 4s ease-in-out infinite alternate; }
@keyframes slide { from { transform: translateX(8px); } to { transform: translateX(188px); } }
@media (prefers-reduced-motion: reduce) { .slide { animation: none; transform: translateX(98px); } }
/* the four measurements */
.slotgrid { display: grid; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); gap: 12px; margin: 12px 0; }
.slot { border: 1px solid var(--line); border-radius: 12px; padding: 12px; background: var(--card); display: flex; flex-direction: column; gap: 8px; }
.slot.active { border-color: var(--accent); box-shadow: 0 0 0 3px color-mix(in srgb, var(--accent) 25%, transparent); }
.slot .head { display: flex; align-items: center; gap: 8px; font-weight: 600; }
.slot .skate { width: 34px; height: 22px; flex: none; }
.slot .state { font-size: .85rem; color: var(--muted); min-height: 2.4em; }
.slot .state.done { color: var(--ok); }
.slot .acts { display: flex; flex-wrap: wrap; gap: 6px; }
.slot .acts button, .slot .acts .file { padding: 6px 10px; font-size: .88rem; }
.slot label.ang { font-size: .88rem; display: flex; align-items: center; gap: 6px; }
.slot label.ang input { width: 5em; padding: 4px 6px; }
/* pictures and charts */
.canvasbox canvas { width: 100%; height: auto; display: block; border-radius: 8px; touch-action: manipulation; }
.scrollbox { overflow-x: auto; border: 1px solid var(--line); border-radius: 8px; }
.scrollbox canvas { display: block; touch-action: manipulation; }
#preview { max-height: 72vh; width: auto; max-width: 100%; margin: 0 auto; cursor: crosshair; }
#overview { cursor: crosshair; }
#aphoto { max-height: 70vh; width: auto; max-width: 100%; margin: 0 auto; cursor: crosshair; }
.livebox canvas { width: 100%; height: auto; display: block; margin-top: 8px; border-radius: 8px; background: #000; }
.bar { height: 10px; background: var(--line); border-radius: 5px; overflow: hidden; }
#barfill { height: 100%; width: 0; background: linear-gradient(90deg, var(--accent), #8fb5ff); transition: width .2s; }
table { border-collapse: collapse; width: 100%; font-variant-numeric: tabular-nums; margin-top: 8px; font-size: .93rem; }
th, td { text-align: right; padding: 6px 10px; border-bottom: 1px solid var(--line); }
th { color: var(--muted); font-weight: 600; font-size: .85rem; }
th:first-child, td:first-child { text-align: left; }
.dot { display: inline-block; width: .8em; height: .8em; border-radius: 50%; vertical-align: middle; }
.dot.rear { background: #ff3b30; } .dot.front { background: #ff9500; }
.combo h3 { margin-top: 14px; }
.error { color: var(--err); font-weight: 600; }
footer { color: var(--muted); font-size: .85rem; padding: 10px 16px 30px; display: flex; align-items: center; gap: 8px; }
@media (max-width: 600px) { h1 { font-size: 1.4rem; } .card { padding: 14px; border-radius: 12px; } }
.guide .tag { font: 700 9px system-ui, sans-serif; fill: #fff; paint-order: stroke; stroke: rgba(0,0,0,.55); stroke-width: 3px; letter-spacing: .04em; text-transform: uppercase; }
.guide .t.m { fill: #555; }
@keyframes slide { from { transform: translateX(20px); } to { transform: translateX(220px); } }
.row.blade { background: var(--soft); border-radius: 10px; padding: 8px 12px; }
.row.blade input { width: 5.5em; }
#edgeview { max-width: none; }
.combo canvas { width: 100%; display: block; margin: 6px 0; }