:root {
  --bg: #f5f4f0;
  --panel: #ffffff;
  --ink: #25241f;
  --muted: #6d6a5f;
  --line: #e2e0d8;
  --accent: #2f6f5e;
  --accent-ink: #ffffff;
  --danger: #b03a2e;
  --chip: #efeee8;
  --chip-sel: #d9e7e1;
  --focus: #1a5fd7;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: "Pretendard", "Apple SD Gothic Neo", "Malgun Gothic", system-ui, sans-serif;
  background: var(--bg);
  color: var(--ink);
  line-height: 1.5;
}
.topbar {
  padding: 20px 24px 14px;
  border-bottom: 1px solid var(--line);
  background: var(--panel);
}
.topbar h1 { margin: 0; font-size: 22px; letter-spacing: -0.02em; }
.topbar .sub { margin: 4px 0 0; color: var(--muted); font-size: 14px; }
main { max-width: 1280px; margin: 0 auto; padding: 18px 24px 40px; }
.panel {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 16px 18px;
  margin-bottom: 18px;
}
.sec-head { display: flex; align-items: center; justify-content: space-between; gap: 12px; flex-wrap: wrap; }
h2 { margin: 0; font-size: 17px; }
h3 { margin: 8px 0 6px; font-size: 13px; color: var(--muted); font-weight: 600; }
.hint { color: var(--muted); font-size: 13px; margin: 6px 0 10px; }
button {
  font: inherit;
  border: 1px solid var(--line);
  background: #fbfaf7;
  border-radius: 7px;
  padding: 5px 10px;
  cursor: pointer;
}
button:hover { background: #f0efe9; }
button:focus-visible, select:focus-visible, input:focus-visible {
  outline: 2px solid var(--focus); outline-offset: 1px;
}
button.primary { background: var(--accent); color: var(--accent-ink); border-color: var(--accent); }
button.primary:hover { background: #285f51; }
button.danger { color: var(--danger); }
select, input[type="text"] {
  font: inherit;
  border: 1px solid var(--line);
  border-radius: 7px;
  padding: 4px 8px;
  background: #fff;
}

/* ---------- rows ---------- */
.row {
  border: 1px solid var(--line);
  border-radius: 9px;
  padding: 10px 12px;
  margin-bottom: 10px;
  background: #fdfdfc;
}
.row-title {
  display: block;
  width: 100%;
  border: none;
  border-bottom: 1px dashed transparent;
  background: transparent;
  font: inherit;
  font-weight: 600;
  font-size: 14px;
  padding: 2px 2px 4px;
  margin-bottom: 8px;
  border-radius: 0;
}
.row-title::placeholder { color: #a8a496; font-weight: 400; }
.row-title:hover { border-bottom-color: var(--line); }
.row-title:focus-visible { outline: none; border-bottom-color: var(--focus); }
.row-line {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: nowrap;
}
.row .size { width: 94px; flex: none; }
.row canvas.cube { flex: none; width: 148px; height: 148px; }
.row .formula {
  flex: 1 1 240px; min-width: 160px;
  display: flex; align-items: center; gap: 4px;
  overflow-x: auto; padding: 6px 4px;
  border: 1px solid var(--line); border-radius: 7px; background: #fff;
  min-height: 40px;
}
.formula .caret { color: var(--accent); font-weight: 700; padding: 0 1px; }
.chip {
  flex: none;
  font-family: ui-monospace, "Cascadia Code", Consolas, monospace;
  font-size: 13px;
  padding: 3px 7px;
  border-radius: 5px;
  border: 1px solid transparent;
  background: var(--chip);
}
.chip.sel { background: var(--chip-sel); border-color: var(--accent); }
.chip.active { outline: 2px solid #d97706; }
.transport { display: flex; gap: 4px; flex: none; }
.transport button { width: 34px; padding: 5px 0; text-align: center; }
.progress { flex: 1 1 120px; min-width: 80px; accent-color: var(--accent); }
.pos { flex: none; font-family: ui-monospace, monospace; font-size: 12px; color: var(--muted); min-width: 44px; text-align: right; }
.warn { margin-top: 8px; font-size: 12px; color: var(--danger); }
.speed { flex: none; width: 66px; }
.row .del { flex: none; }
.editor { margin-top: 10px; border-top: 1px dashed var(--line); padding-top: 10px; }
.editor[hidden] { display: none; }
.mv-group { display: flex; align-items: baseline; gap: 6px; flex-wrap: wrap; margin-bottom: 6px; }
.mv-group .glabel { font-size: 12px; color: var(--muted); width: 110px; flex: none; }
.mv {
  font-family: ui-monospace, "Cascadia Code", Consolas, monospace;
  font-size: 13px;
  padding: 3px 7px;
}
.edit-actions { display: flex; gap: 6px; align-items: center; flex-wrap: wrap; margin-top: 8px; }
.edit-actions input[type="text"] { width: 200px; font-family: ui-monospace, monospace; font-size: 13px; }
.err-text { color: var(--danger); font-size: 12px; }

/* ---------- painter ---------- */
.size-tabs { display: flex; gap: 6px; }
.size-tabs button[aria-selected="true"] { background: var(--accent); color: #fff; border-color: var(--accent); }
.painter-wrap { display: flex; gap: 22px; flex-wrap: wrap; align-items: flex-start; }
.palette-col { min-width: 150px; }
.palette { display: grid; grid-template-columns: repeat(2, auto); gap: 6px; }
.swatch {
  display: flex; align-items: center; gap: 6px;
  padding: 5px 8px; border-radius: 7px;
}
.swatch .dot { width: 18px; height: 18px; border-radius: 4px; border: 1px solid #0003; flex: none; }
.swatch[aria-checked="true"] { outline: 2px solid var(--accent); }
.counts { display: flex; flex-direction: column; gap: 3px; font-size: 13px; }
.counts .cnt { display: flex; align-items: center; gap: 6px; }
.counts .cnt.bad { color: var(--danger); font-weight: 600; }
.counts .dot { width: 12px; height: 12px; border-radius: 3px; border: 1px solid #0003; }
.net-scroll {
  overflow-x: auto;
  max-width: 100%;
  padding-bottom: 8px;
  -webkit-overflow-scrolling: touch;
}
.net {
  display: grid;
  grid-template-columns: repeat(4, auto);
  grid-template-rows: repeat(3, auto);
  gap: 10px;
  align-items: start;
  width: max-content;
}
.net .face { display: grid; gap: 1px; background: #d8d6cd; padding: 2px; border-radius: 5px; }
.net .face-label { font-size: 11px; color: var(--muted); text-align: center; margin-bottom: 2px; }
.net .st { border: none; padding: 0; border-radius: 2px; cursor: pointer; }
.net .st:focus-visible { outline: 2px solid var(--focus); z-index: 1; }
.painter-actions { margin-top: 14px; display: flex; gap: 8px; }
.errors { color: var(--danger); font-size: 13px; margin: 10px 0 0; padding-left: 20px; }
.errors:empty { display: none; }
.ok { color: var(--accent); font-size: 13px; font-weight: 600; margin: 8px 0 0; }
.ok:empty { display: none; }
.limits { margin-top: 12px; font-size: 13px; color: var(--muted); }
.notation-doc p { margin: 4px 0; font-size: 14px; }
.notation-doc code { background: var(--chip); padding: 1px 5px; border-radius: 4px; font-family: ui-monospace, monospace; }
.foot { text-align: center; color: var(--muted); font-size: 12px; padding: 16px; }

@media (max-width: 900px) {
  .row-line { flex-wrap: wrap; }
  .row .formula { order: 5; flex-basis: 100%; }
  .progress { order: 6; flex-basis: 100%; }
}

/* ---- menus, views, auth ---- */
.topbar { display: flex; flex-wrap: wrap; gap: 10px; align-items: flex-end; justify-content: space-between; }
#menu { display: flex; gap: 4px; align-items: center; margin-left: auto; }
#menu a { padding: 6px 12px; border-radius: 6px; text-decoration: none; color: var(--ink); font-weight: 500; border: 1px solid transparent; }
#menu a.on { background: var(--accent); color: #fff; }
#menu a:focus-visible { outline: 2px solid var(--focus); }
#menu a[hidden] { display: none; }
#auth-btn { margin-left: 8px; }
.auth-msg { color: var(--danger); font-size: 13px; margin: 4px 0 0; min-height: 0; }
.auth-msg:empty { display: none; }
.hint, .hint-list { color: var(--muted); font-size: 13px; }
.hint-list li { margin-bottom: 4px; }
.row-title-text { font-size: 14px; font-weight: 600; margin: 0 0 8px; }

/* ---- intro demos ---- */
.demo-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(340px, 1fr)); gap: 14px; margin: 10px 0 18px; }
.demo { border: 1px solid var(--line); border-radius: 8px; padding: 10px 12px; background: #fdfdfc; }
.demo h3 { margin: 0 0 4px; font-size: 14px; }
.demo-code { font-family: ui-monospace, monospace; font-size: 12px; color: var(--accent); margin: 0 0 6px; }

/* ---- editor layout ---- */
.edit-layout { display: flex; gap: 18px; align-items: flex-start; flex-wrap: wrap; }
.edit-side { flex: 0 0 220px; }
.edit-main { flex: 1 1 500px; min-width: 300px; }
.sel-list { display: flex; flex-direction: column; gap: 4px; margin-bottom: 8px; max-height: 320px; overflow-y: auto; }
.sel-item { text-align: left; padding: 7px 10px; border: 1px solid var(--line); border-radius: 6px; background: #fff; cursor: pointer; font-size: 13px; }
.sel-item.on { border-color: var(--accent); background: #eaf4ef; font-weight: 600; }
.sel-item.sel-new { border-style: dashed; color: var(--accent); font-weight: 600; }
.wide { width: 100%; }
.guard { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; border: 1px solid #d97706; background: #fdf3e3; border-radius: 8px; padding: 10px 12px; margin: 10px 0; font-size: 13px; }
.edit-actions2 { display: flex; gap: 8px; align-items: center; margin-top: 10px; }
.saved-msg { color: var(--accent); font-size: 13px; }
.sel-edit { flex: none; }
.tbl { border-collapse: collapse; font-size: 13px; margin-bottom: 18px; }
.tbl th, .tbl td { border: 1px solid var(--line); padding: 5px 10px; text-align: left; }
.tbl th { background: #f3f1ea; }
main > section[hidden] { display: none; }