/* SchoolCAD
 * Layout concept: a slimmed CAD workspace laid out like a workshop drawing sheet:
 * design steps on the left, the model on the stage, a title-block property panel on the right. */
:root {
  --bg: #eef0f3;
  --panel: #ffffff;
  --panel-2: #f6f7f9;
  --stage: #e4e7ec;
  --line: #d5d9e0;
  --line-strong: #b9bfca;
  --ink: #1b1d22;
  --muted: #5f6673;
  --accent: #2a55c9;
  --accent-ink: #ffffff;
  --accent-weak: #e2e9fb;
  --timber: #a8603f;
  --ok: #2c8350;
  --warn: #9a6200;
  --err: #c0362b;
  --info: #4f5b70;
  --shadow: 0 1px 2px rgba(20, 24, 33, 0.08), 0 6px 24px rgba(20, 24, 33, 0.06);
  --font-ui: "Segoe UI Variable Text", "Segoe UI", system-ui, -apple-system, "Helvetica Neue", Arial, sans-serif;
  --font-display: "Avenir Next", "Segoe UI Variable Display", "Segoe UI", system-ui, sans-serif;
  --font-mono: ui-monospace, "Cascadia Mono", "SF Mono", Menlo, Consolas, monospace;
  --r: 6px;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #14161a; --panel: #1c1f25; --panel-2: #22262d; --stage: #101215; --line: #2d3139; --line-strong: #3d434e;
    --ink: #e7e9ee; --muted: #9aa2b0; --accent: #7d9dff; --accent-ink: #0d1430; --accent-weak: #222e52; --timber: #d79a79;
    --ok: #5cc285; --warn: #e3a83a; --err: #ff7a6b; --info: #a7b2c6;
    --shadow: 0 1px 2px rgba(0, 0, 0, 0.4), 0 8px 28px rgba(0, 0, 0, 0.35);
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #14161a; --panel: #1c1f25; --panel-2: #22262d; --stage: #101215; --line: #2d3139; --line-strong: #3d434e;
  --ink: #e7e9ee; --muted: #9aa2b0; --accent: #7d9dff; --accent-ink: #0d1430; --accent-weak: #222e52; --timber: #d79a79;
  --ok: #5cc285; --warn: #e3a83a; --err: #ff7a6b; --info: #a7b2c6;
  --shadow: 0 1px 2px rgba(0, 0, 0, 0.4), 0 8px 28px rgba(0, 0, 0, 0.35);
  color-scheme: dark;
}

* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0; background: var(--bg); color: var(--ink); font: 14px/1.45 var(--font-ui);
  display: grid; grid-template-rows: auto 1fr auto; overflow: hidden;
}
button, input, select { font: inherit; color: inherit; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
[hidden] { display: none !important; }

/* ---------- top bar ---------- */
.topbar {
  display: flex; align-items: center; gap: 16px; flex-wrap: wrap;
  padding-block: 8px; padding-left: max(16px, env(safe-area-inset-left, 0px)); padding-right: max(16px, env(safe-area-inset-right, 0px));
  background: var(--panel); border-bottom: 1px solid var(--line);
}
.brand { display: flex; align-items: center; gap: 10px; min-width: 0; }
.brand svg { flex: none; }
.brand b { font-family: var(--font-display); font-size: 16px; letter-spacing: 0.01em; display: block; line-height: 1.1; }
.brand span { color: var(--muted); font-size: 12px; }
/* mode switch in the top bar (quick design / guided modelling) */
.modes { display: inline-flex; border: 1px solid var(--line); border-radius: 999px; padding: 2px; background: var(--panel-2); }
.modes .mode { padding: 4px 12px; border-radius: 999px; color: var(--muted); text-decoration: none; font-size: 13px; white-space: nowrap; }
.modes .mode:hover { color: var(--ink); }
.modes .mode[aria-current="page"] { background: var(--panel); color: var(--ink); box-shadow: 0 0 0 1px var(--line); font-weight: 600; }
.who { display: flex; gap: 8px; margin-left: auto; }
.who input { width: 150px; padding: 6px 9px; border: 1px solid var(--line); border-radius: var(--r); background: var(--panel-2); }
.who input#student-class { width: 90px; }
.actions { display: flex; gap: 6px; align-items: center; }
.btn {
  display: inline-flex; align-items: center; gap: 6px; padding: 6px 11px; border-radius: var(--r);
  border: 1px solid var(--line); background: var(--panel); cursor: pointer; white-space: nowrap;
}
.btn:hover { border-color: var(--line-strong); background: var(--panel-2); }
.btn.primary { background: var(--accent); color: var(--accent-ink); border-color: var(--accent); }
.btn.primary:hover { filter: brightness(1.06); background: var(--accent); }
.btn.icon { padding: 6px 8px; }
.btn:disabled { opacity: 0.45; cursor: default; }
.btn svg { width: 16px; height: 16px; }
.menu { position: relative; }
.menu-list {
  position: absolute; right: 0; top: calc(100% + 6px); z-index: 30; min-width: 260px; padding: 6px;
  background: var(--panel); border: 1px solid var(--line); border-radius: 8px; box-shadow: var(--shadow);
}
.menu-list button { display: grid; grid-template-columns: 1fr; text-align: left; width: 100%; padding: 8px 10px; border: 0; background: none; border-radius: 5px; cursor: pointer; }
.menu-list button:hover { background: var(--accent-weak); }
.menu-list small { color: var(--muted); display: block; font-size: 12px; }
.menu-list hr { border: 0; border-top: 1px solid var(--line); margin: 6px 0; }

/* ---------- workspace ---------- */
.workspace { display: grid; grid-template-columns: 236px minmax(0, 1fr) 340px; min-height: 0; }
.tree { background: var(--panel); border-right: 1px solid var(--line); overflow: auto; padding: 12px 10px; }
.tree h2, .props h2 { font: 600 11px/1 var(--font-ui); letter-spacing: 0.09em; text-transform: uppercase; color: var(--muted); margin: 4px 6px 10px; }
.steps { list-style: none; margin: 0; padding: 0; display: grid; gap: 2px; }
.step {
  display: grid; grid-template-columns: 22px 1fr auto; align-items: center; gap: 8px; width: 100%;
  padding: 8px 8px; border: 0; border-radius: var(--r); background: none; text-align: left; cursor: pointer;
}
.step:hover { background: var(--panel-2); }
.step[aria-current="true"] { background: var(--accent-weak); }
.step .num {
  width: 22px; height: 22px; border-radius: 50%; display: grid; place-items: center; font: 600 11px var(--font-mono);
  border: 1px solid var(--line-strong); color: var(--muted); background: var(--panel);
}
.step[aria-current="true"] .num { border-color: var(--accent); color: var(--accent); }
.step .label { font-weight: 600; }
.step .sub { display: block; color: var(--muted); font-size: 12px; font-weight: 400; }
.dot { width: 9px; height: 9px; border-radius: 50%; background: var(--line-strong); }
.dot.ok { background: var(--ok); } .dot.warn { background: var(--warn); } .dot.error { background: var(--err); } .dot.info { background: var(--info); }
.subparts { list-style: none; margin: 2px 0 6px 30px; padding: 0; display: grid; gap: 1px; }
.subparts button { width: 100%; text-align: left; border: 0; background: none; padding: 4px 8px; border-radius: 5px; color: var(--muted); cursor: pointer; display: flex; justify-content: space-between; gap: 6px; font-size: 13px; }
.subparts button:hover, .subparts button[aria-pressed="true"] { background: var(--panel-2); color: var(--ink); }
.lock { font-size: 11px; color: var(--muted); display: inline-flex; gap: 4px; align-items: center; }

/* ---------- stage ---------- */
.stage { display: grid; grid-template-rows: auto 1fr; min-width: 0; min-height: 0; background: var(--stage); position: relative; }
.stage-tabs { display: flex; gap: 2px; padding: 8px 10px 0; }
.tab { padding: 7px 14px; border: 1px solid transparent; border-bottom: 0; border-radius: 6px 6px 0 0; background: none; cursor: pointer; color: var(--muted); font-weight: 600; }
.tab[aria-selected="true"] { background: var(--panel); color: var(--ink); border-color: var(--line); }
.stage-body { position: relative; min-height: 0; margin: 0 10px 10px; background: var(--panel); border: 1px solid var(--line); border-radius: 0 8px 8px 8px; overflow: hidden; }
.stage-body canvas.main { position: absolute; inset: 0; width: 100%; height: 100%; display: block; touch-action: none; }
#sketch { background: var(--panel-2); cursor: default; }
#sketch:focus { outline: none; }
.sheet-frame { position: absolute; inset: 8px; border: 1px solid var(--line); border-radius: 4px; pointer-events: none; }
.view-tools {
  position: absolute; left: 12px; top: 12px; display: flex; gap: 6px; flex-wrap: wrap; align-items: center;
  padding: 5px; background: color-mix(in srgb, var(--panel) 92%, transparent); border: 1px solid var(--line); border-radius: 8px; box-shadow: var(--shadow); max-width: calc(100% - 24px);
}
.seg { display: inline-flex; border: 1px solid var(--line); border-radius: var(--r); overflow: hidden; }
.seg button { border: 0; background: var(--panel); padding: 5px 9px; cursor: pointer; font-size: 13px; }
.seg button + button { border-left: 1px solid var(--line); }
.seg button[aria-pressed="true"] { background: var(--accent); color: var(--accent-ink); }
.toggle { display: inline-flex; align-items: center; gap: 6px; padding: 4px 8px; font-size: 13px; cursor: pointer; border-radius: var(--r); user-select: none; }
.toggle input { accent-color: var(--accent); }
.range-mini { display: inline-flex; align-items: center; gap: 6px; font-size: 13px; padding: 0 6px; }
.range-mini input { width: 90px; accent-color: var(--accent); }
.light-btn[aria-pressed="true"] { background: #f6c945; color: #2a2000; border-color: #e0b330; }
.proj { position: absolute; right: 12px; bottom: 10px; display: flex; align-items: center; gap: 8px; color: var(--muted); font: 11px var(--font-mono); pointer-events: none; }
.proj svg { width: 44px; height: 22px; }
.mini {
  position: absolute; right: 12px; bottom: 12px; width: 210px; height: 230px; border: 1px solid var(--line); border-radius: 8px;
  background: var(--stage); box-shadow: var(--shadow); overflow: hidden;
}
.mini canvas { width: 100%; height: 100%; display: block; }
.mini span { position: absolute; left: 8px; top: 6px; font: 600 10px var(--font-ui); letter-spacing: 0.08em; text-transform: uppercase; color: var(--muted); }
.sketch-hint { position: absolute; left: 12px; bottom: 10px; color: var(--muted); font-size: 12px; max-width: calc(100% - 250px); pointer-events: none; }
.gl-error { position: absolute; inset: 0; display: grid; place-items: center; padding: 24px; text-align: center; color: var(--muted); }

/* ---------- properties ---------- */
.props { background: var(--panel); border-left: 1px solid var(--line); overflow: auto; min-width: 0; }
.titleblock { display: grid; grid-template-columns: 1fr 1fr; border-bottom: 1px solid var(--line-strong); font-size: 12px; }
.titleblock div { padding: 7px 12px; border-right: 1px solid var(--line); border-bottom: 1px solid var(--line); min-width: 0; }
.titleblock div:nth-child(2n) { border-right: 0; }
.titleblock .wide { grid-column: 1 / -1; border-right: 0; }
.titleblock label { display: block; font: 600 9.5px var(--font-ui); letter-spacing: 0.1em; text-transform: uppercase; color: var(--muted); }
.titleblock strong { font-family: var(--font-display); font-size: 17px; }
.titleblock span { font-family: var(--font-mono); font-size: 12px; overflow-wrap: anywhere; }
.props-body { padding: 14px 14px 28px; display: grid; grid-template-columns: minmax(0, 1fr); gap: 18px; }
.props-body > *, .group > * { min-width: 0; }
.group { display: grid; gap: 10px; }
.group > h3 { margin: 0; font: 600 13px var(--font-ui); display: flex; align-items: baseline; justify-content: space-between; gap: 8px; }
.group > h3 small { font-weight: 400; color: var(--muted); font-size: 12px; }
.help { color: var(--muted); font-size: 12.5px; margin: 0; }
.field { display: grid; grid-template-columns: 84px minmax(0, 1fr) 84px; align-items: center; gap: 8px; }
.field label { font-size: 13px; color: var(--muted); }
.field input[type=range] { width: 100%; accent-color: var(--accent); }
.num { display: flex; align-items: center; border: 1px solid var(--line); border-radius: var(--r); background: var(--panel-2); }
.num input { width: 100%; border: 0; background: none; padding: 5px 2px 5px 7px; -moz-appearance: textfield; appearance: textfield; font: 13px var(--font-mono); font-variant-numeric: tabular-nums; min-width: 0; }
.num input::-webkit-outer-spin-button, .num input::-webkit-inner-spin-button { -webkit-appearance: none; margin: 0; }
.num span { padding-right: 7px; color: var(--muted); font-size: 11px; }
.choices { display: flex; flex-wrap: wrap; gap: 6px; }
.chip { padding: 5px 10px; border: 1px solid var(--line); border-radius: 99px; background: var(--panel); cursor: pointer; font-size: 13px; }
.chip:hover { border-color: var(--line-strong); }
.chip[aria-pressed="true"] { border-color: var(--accent); background: var(--accent-weak); color: var(--ink); font-weight: 600; }
.shape-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(54px, 1fr)); gap: 6px; }
.shape-grid button { display: grid; justify-items: center; gap: 2px; padding: 6px 2px 5px; border: 1px solid var(--line); border-radius: var(--r); background: var(--panel); cursor: pointer; font-size: 10.5px; color: var(--muted); }
.shape-grid button:hover { border-color: var(--accent); color: var(--ink); }
.shape-grid canvas { width: 30px; height: 30px; }
.swatches { display: flex; flex-wrap: wrap; gap: 6px; }
.swatch { width: 26px; height: 26px; border-radius: 50%; border: 2px solid var(--panel); box-shadow: 0 0 0 1px var(--line-strong); cursor: pointer; padding: 0; }
.swatch[aria-pressed="true"] { box-shadow: 0 0 0 2px var(--accent); }
.row { display: flex; gap: 6px; flex-wrap: wrap; }
.corner-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
.corner { border: 1px solid var(--line); border-radius: var(--r); padding: 8px; display: grid; gap: 6px; background: var(--panel-2); }
.corner b { font-size: 12px; }
.corner select { width: 100%; padding: 4px; border: 1px solid var(--line); border-radius: 5px; background: var(--panel); }
.checks { list-style: none; margin: 0; padding: 0; display: grid; gap: 6px; }
.checks li { display: grid; grid-template-columns: 18px minmax(0, 1fr); gap: 8px; font-size: 13px; align-items: start; }
.checks li::before { content: ""; width: 10px; height: 10px; border-radius: 50%; margin-top: 4px; background: var(--info); }
.checks li.ok::before { background: var(--ok); } .checks li.warn::before { background: var(--warn); } .checks li.error::before { background: var(--err); }
.checks li.error { color: var(--err); }
.table { width: 100%; border-collapse: collapse; font-size: 12.5px; }
.table th, .table td { text-align: left; padding: 5px 4px; border-bottom: 1px solid var(--line); vertical-align: top; }
.table th { color: var(--muted); font-weight: 600; font-size: 11px; }
.table td.mono { font-family: var(--font-mono); font-variant-numeric: tabular-nums; white-space: nowrap; }
.table-wrap { overflow-x: auto; }
.layer-list { list-style: none; margin: 0; padding: 0; display: grid; gap: 4px; }
.layer-list li { display: flex; align-items: center; gap: 8px; font-size: 13px; }
.layer-list i { width: 14px; height: 14px; border-radius: 3px; border: 1px solid var(--line-strong); }
.export-grid { display: grid; gap: 8px; }
.export-grid .btn { justify-content: flex-start; padding: 10px 12px; white-space: normal; text-align: left; }
.export-grid .btn small { color: inherit; opacity: 0.75; display: block; font-size: 12px; }
.empty-sel { border: 1px dashed var(--line-strong); border-radius: var(--r); padding: 12px; color: var(--muted); font-size: 13px; }
.switch { display: flex; align-items: center; justify-content: space-between; gap: 10px; }
.switch input { width: 38px; height: 22px; accent-color: var(--accent); }

/* ---------- status bar & toast ---------- */
.statusbar {
  display: flex; gap: 16px; align-items: center; font-size: 12px; color: var(--muted); background: var(--panel); border-top: 1px solid var(--line);
  padding-block: 5px; padding-left: max(16px, env(safe-area-inset-left, 0px)); padding-right: max(16px, env(safe-area-inset-right, 0px));
}
.statusbar .sp { margin-left: auto; font-family: var(--font-mono); }
.about-link { border: 0; background: none; color: var(--accent); font: inherit; cursor: pointer; padding: 0; text-decoration: underline; text-underline-offset: 2px; }
.dlg.about p, .dlg.about ul { margin: 0; line-height: 1.55; }
.dlg.about ul { padding-left: 20px; display: grid; gap: 6px; }
.toast {
  position: fixed; left: 50%; bottom: calc(46px + env(safe-area-inset-bottom, 0px)); transform: translateX(-50%); z-index: 50;
  background: var(--ink); color: var(--panel); padding: 9px 14px; border-radius: 8px; box-shadow: var(--shadow); font-size: 13px; max-width: calc(100vw - 32px);
  display: flex; gap: 12px; align-items: center;
}
.toast button { background: none; border: 0; color: inherit; text-decoration: underline; cursor: pointer; padding: 0; }

/* ---------- dialogs ---------- */
dialog { border: 1px solid var(--line); border-radius: 10px; padding: 0; background: var(--panel); color: var(--ink); box-shadow: var(--shadow); width: min(720px, calc(100vw - 32px)); }
dialog::backdrop { background: rgba(10, 12, 16, 0.45); }
.dlg { padding: 18px; display: grid; gap: 14px; }
.dlg h2 { margin: 0; font-family: var(--font-display); font-size: 19px; }
.dlg .previews { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.dlg .previews figure { margin: 0; display: grid; gap: 4px; }
.dlg .previews figcaption { font-size: 12px; color: var(--muted); }
.dlg .previews canvas, .dlg .previews img { width: 100%; height: 220px; object-fit: contain; background: var(--panel-2); border: 1px solid var(--line); border-radius: 6px; }
.dlg .bar { display: flex; justify-content: flex-end; gap: 8px; flex-wrap: wrap; }
.dlg .field { grid-template-columns: 110px minmax(0, 1fr) 56px; }
.dlg textarea { width: 100%; min-height: 70px; padding: 8px; border: 1px solid var(--line); border-radius: var(--r); background: var(--panel-2); font: 16px var(--font-ui); }
.drop { border: 1.5px dashed var(--line-strong); border-radius: 8px; padding: 18px; text-align: center; color: var(--muted); cursor: pointer; }
.drop.over { border-color: var(--accent); background: var(--accent-weak); }

/* ---------- small screens ---------- */
@media (max-width: 1100px) { .workspace { grid-template-columns: 200px minmax(0, 1fr) 300px; } .who input { width: 120px; } }
@media (max-width: 900px) {
  body { overflow: auto; height: auto; display: block; }
  .workspace { display: flex; flex-direction: column; }
  .tree { border-right: 0; border-bottom: 1px solid var(--line); padding: 8px; overflow-x: auto; }
  .tree h2 { display: none; }
  .steps { grid-auto-flow: column; grid-auto-columns: max-content; }
  .subparts { display: none; }
  .step .sub { display: none; }
  .stage { height: 62vh; min-height: 380px; }
  .props { border-left: 0; }
  .who { margin-left: 0; width: 100%; }
  .who input { flex: 1; width: auto; }
  .actions { flex-wrap: wrap; }
  .mini { width: 130px; height: 150px; }
  .sketch-hint { display: none; }
}
@media (prefers-reduced-motion: reduce) { * { transition: none !important; animation: none !important; } }