/* App shell: slim top bar, step rail on the left, one working surface. */
html, body.app { height: 100%; }
body.app { font: 15px/1.55 var(--f-sans); background: var(--bg); }
body.app .brand { font-size: 19px; }
body.app .brand-mark { width: 26px; height: 26px; }
.appbar { position: sticky; top: env(safe-area-inset-top, 0px); z-index: 40; height: 60px; display: flex; align-items: center; gap: 14px; padding-inline: 20px; background: color-mix(in srgb, var(--bg) 94%, transparent); backdrop-filter: blur(10px); border-bottom: 1px solid var(--line); }
.appbar .spacer { flex: 1; }
.appbar .acts { display: flex; gap: 6px; align-items: center; }
.appbar .divider { width: 1px; height: 22px; background: var(--line); margin-inline: 4px; }
.shell { display: grid; grid-template-columns: 228px minmax(0, 1fr); min-height: calc(100% - 56px); }
.rail { border-right: 1px solid var(--line); padding: 18px 12px 24px; position: sticky; top: calc(56px + env(safe-area-inset-top, 0px)); height: calc(100vh - 56px); overflow-y: auto; }
.rail-group { display: grid; gap: 1px; margin-bottom: 18px; }
.rail-label { font: 500 11px/1 var(--f-mono); color: var(--muted); letter-spacing: .08em; text-transform: uppercase; padding: 6px 10px 8px; }
.tab { display: flex; align-items: center; gap: 11px; width: 100%; text-align: left; border: 0; background: transparent; color: var(--ink-2); font: 500 15px/1 var(--f-sans); padding: 10px 12px; border-radius: 6px; cursor: pointer; }
.tab .dot { width: 22px; height: 22px; border-radius: 50%; border: 1px solid var(--line-2); display: inline-grid; place-items: center; font: 600 11.5px/1 var(--f-sans); color: var(--muted); flex: none; background: var(--surface); }
.tab.done .dot { background: var(--accent); border-color: var(--accent); color: var(--accent-ink); }
.tab .ic { width: 20px; display: inline-grid; place-items: center; color: var(--muted); flex: none; }
.tab .ic svg { width: 16px; height: 16px; }
.tab:hover { background: var(--sunken); color: var(--ink); }
.tab[aria-selected="true"] { background: var(--surface); color: var(--ink); box-shadow: inset 0 0 0 1px var(--line); }
.tab[aria-selected="true"] .dot { border-color: var(--accent); color: var(--accent); }
.tab[aria-selected="true"] .ic { color: var(--accent); }
.tab:disabled { opacity: .35; cursor: not-allowed; background: transparent; }
.rail-foot { margin-top: 12px; padding: 12px 10px; border-top: 1px solid var(--line); font-size: 12px; color: var(--muted); line-height: 1.5; }
main.work { padding: 28px 32px 80px; min-width: 0; }
.panel { display: grid; gap: 20px; max-width: 1240px; }
.panel-head { display: flex; flex-wrap: wrap; align-items: flex-end; justify-content: space-between; gap: 12px 20px; }
.panel-head h2 { font-size: 26px; }
.panel-head p { color: var(--muted); margin-top: 6px; max-width: 68ch; }
.panel-head .acts { display: flex; gap: 8px; flex-wrap: wrap; }
@media (max-width: 900px) {
  .shell { grid-template-columns: minmax(0, 1fr); }
  .rail { position: sticky; top: calc(56px + env(safe-area-inset-top, 0px)); z-index: 30; height: auto; display: flex; gap: 4px; overflow-x: auto; padding: 8px 12px; border-right: 0; border-bottom: 1px solid var(--line); background: var(--bg); }
  .rail-group { display: flex; gap: 2px; margin: 0; }
  .rail-label, .rail-foot { display: none; }
  .tab { width: auto; white-space: nowrap; padding: 8px 10px; }
  main.work { padding: 20px 16px 64px; }
  .appbar .hide-sm { display: none; }
}

/* surfaces */
.card { background: var(--surface); border: 1px solid var(--line); border-radius: var(--r-lg); padding: 18px; min-width: 0; display: grid; gap: 14px; align-content: start; }
.card.flat { background: transparent; }
.card-head { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 8px; }
.card-head h3 { font-size: 15px; }
.card-head .acts { display: flex; gap: 6px; }
.grid-2 { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 20px; }
.grid-3 { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 16px; }
@media (max-width: 1000px) { .grid-2, .grid-3 { grid-template-columns: minmax(0, 1fr); } }
.note { font-size: 12.5px; color: var(--muted); line-height: 1.55; }
.hint { font-size: 12.5px; color: var(--muted); }

/* forms */
label.f { display: grid; gap: 6px; font-size: 12.5px; color: var(--muted); font-weight: 500; min-width: 0; }
select, input[type=text], input[type=number] { font: 14px var(--f-sans); color: var(--ink); background: var(--surface); border: 1px solid var(--line-2); border-radius: 8px; padding: 8px 10px; width: 100%; min-width: 0; }
select:focus, input:focus, textarea:focus { border-color: var(--accent); box-shadow: var(--ring); outline: none; }
input[type=checkbox] { accent-color: var(--accent); width: 16px; height: 16px; margin: 0; }
.check { display: inline-flex; align-items: center; gap: 8px; font-size: 13.5px; color: var(--ink); cursor: pointer; }
.form-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(180px, 1fr)); gap: 14px; }
details.adv { border: 1px solid var(--line); border-radius: var(--r); background: var(--surface); }
details.adv > summary { cursor: pointer; list-style: none; padding: 14px 16px; font-weight: 500; display: flex; align-items: center; justify-content: space-between; }
details.adv > summary::-webkit-details-marker { display: none; }
details.adv > summary::after { content: "+"; font: 400 18px/1 var(--f-mono); color: var(--muted); }
details.adv[open] > summary::after { content: "−"; }
details.adv .adv-body { padding: 0 16px 16px; display: grid; gap: 18px; }
.group-title { font: 500 11px/1 var(--f-mono); letter-spacing: .08em; text-transform: uppercase; color: var(--muted); margin-bottom: 10px; }
.seg { display: inline-flex; padding: 3px; background: var(--sunken); border-radius: 9px; gap: 2px; }
.seg button { border: 0; background: transparent; color: var(--ink-2); font: 500 13px/1 var(--f-sans); padding: 8px 12px; border-radius: 7px; cursor: pointer; display: inline-flex; align-items: center; gap: 6px; }
.seg button svg { width: 15px; height: 15px; }
.seg button[aria-pressed="true"] { background: var(--surface); color: var(--ink); box-shadow: 0 1px 2px rgba(0,0,0,.08), inset 0 0 0 1px var(--line); }
.seg.sm button { padding: 5px 8px; font-size: 12px; }
textarea.code { width: 100%; min-height: 360px; resize: vertical; font: 13.5px/1.7 var(--f-mono); color: var(--ink); background: var(--surface); border: 1px solid var(--line-2); border-radius: var(--r); padding: 14px 16px; tab-size: 2; }

/* drop zone */
.drop { border: 1.5px dashed var(--line-2); border-radius: var(--r-lg); padding: 36px 20px; display: grid; gap: 8px; place-items: center; text-align: center; cursor: pointer; background: var(--surface); transition: border-color .15s, background .15s; }
.drop:hover { border-color: var(--ink-2); }
.drop.over { border-color: var(--accent); background: var(--accent-soft); }
.drop svg { width: 28px; height: 28px; color: var(--muted); }
.drop strong { font-size: 16px; font-weight: 600; }

/* messages */
.msg { border-radius: var(--r); padding: 11px 14px; font-size: 13.5px; border: 1px solid var(--line); background: var(--surface); line-height: 1.55; }
.msg.err { border-color: color-mix(in srgb, var(--bad) 40%, var(--line)); background: var(--bad-soft); }
.msg.ok { border-color: color-mix(in srgb, var(--good) 35%, var(--line)); background: var(--good-soft); }
.msg.info { border-color: var(--accent-line); background: var(--accent-soft); }
.msg ul { margin: 6px 0 0; padding-left: 18px; }
.msg b { font-weight: 600; }
.banner { display: flex; flex-wrap: wrap; gap: 12px 20px; align-items: center; justify-content: space-between; border: 1px solid var(--accent-line); background: var(--accent-soft); border-radius: var(--r-lg); padding: 16px 18px; }
.banner p { max-width: 70ch; }
.kpis { display: grid; grid-template-columns: repeat(auto-fill, minmax(140px, 1fr)); gap: 10px; }
.kpi { border: 1px solid var(--line); border-radius: var(--r); padding: 12px 14px; background: var(--surface); }
.kpi b { display: block; font: 600 22px/1.2 var(--f-sans); letter-spacing: -0.02em; font-variant-numeric: tabular-nums; }
.kpi span { font-size: 12px; color: var(--muted); }
.progress { height: 4px; border-radius: 99px; background: var(--sunken); overflow: hidden; }
.progress > i { display: block; height: 100%; width: 0; background: var(--accent); transition: width .2s; }

/* tables */
.tscroll { overflow-x: auto; border: 1px solid var(--line); border-radius: var(--r); max-width: 100%; }
.tscroll.tall { max-height: 480px; overflow-y: auto; }
table.res { border-collapse: collapse; width: 100%; font-size: 13px; font-variant-numeric: tabular-nums; }
table.res th { text-align: left; font: 600 12px/1.3 var(--f-sans); color: var(--ink-2); background: var(--sunken); padding: 9px 12px; white-space: nowrap; position: sticky; top: 0; z-index: 1; border-bottom: 1px solid var(--line); }
table.res td { padding: 8px 12px; border-top: 1px solid var(--line); white-space: nowrap; color: var(--ink); }
table.res tbody tr:first-child td { border-top: 0; }
table.res td.num, table.res th.num { text-align: right; }
table.res td.num { font-family: var(--f-mono); font-size: 12.5px; }
table.res tbody tr:hover td { background: color-mix(in srgb, var(--sunken) 70%, transparent); }
td.good { color: var(--good) !important; } td.warn { color: var(--warn) !important; background: var(--warn-soft); } td.bad { color: var(--bad) !important; background: var(--bad-soft); font-weight: 600; }
td.own { font-weight: 700; } td.diag { font-weight: 700; color: var(--accent) !important; }
.cfg td.sym { text-align: center; font-size: 18px; line-height: 1; }
.cfg td.sym.periph { font-size: 12px; }
.chip { display: inline-flex; align-items: center; gap: 6px; font: 500 12px/1 var(--f-sans); padding: 5px 9px; border-radius: 99px; background: var(--sunken); color: var(--ink-2); white-space: nowrap; border: 1px solid transparent; }
.chip.acc { background: var(--accent-soft); color: var(--accent); }
.chip.good { background: var(--good-soft); color: var(--good); }

/* figures */
.paper { background: #ffffff; border: 1px solid var(--line); border-radius: var(--r-lg); overflow: auto; max-width: 100%; position: relative; }
.paper svg { display: block; }
.paper.canvas { touch-action: none; height: 560px; resize: vertical; overflow: hidden; min-height: 320px; background-color: #ffffff; background-image: radial-gradient(#dde1ea 1px, transparent 1px); background-size: 20px 20px; }
.paper.canvas.mode-connect { cursor: crosshair; }
.paper.canvas.mode-erase { cursor: not-allowed; }
.canvas-empty { position: absolute; inset: 0; display: grid; place-items: center; text-align: center; padding: 24px; color: #6b7077; font-size: 14px; pointer-events: none; }
.canvas-empty b { color: #141619; display: block; font-size: 16px; margin-bottom: 4px; }
.toolbar { display: flex; flex-wrap: wrap; gap: 10px 14px; align-items: flex-end; }
.toolbar label.f { min-width: 140px; }
.canvas-bar { display: flex; flex-wrap: wrap; gap: 10px; align-items: center; justify-content: space-between; }
.canvas-bar .left, .canvas-bar .right { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; }
.tool-hint { font-size: 13px; color: var(--muted); min-height: 20px; }
.tool-hint b { color: var(--ink); font-weight: 600; }

/* model builder */
.builder { display: grid; grid-template-columns: 300px minmax(0, 1fr); gap: 20px; align-items: start; }
@media (max-width: 1100px) { .builder { grid-template-columns: minmax(0, 1fr); } }
.b-side { display: grid; gap: 16px; position: sticky; top: 76px; max-height: calc(100vh - 96px); overflow-y: auto; padding-right: 2px; }
@media (max-width: 1100px) { .b-side { position: static; max-height: none; } }
.b-sec { display: grid; gap: 10px; }
.b-sec-head { display: flex; align-items: center; justify-content: space-between; gap: 8px; }
.b-sec-head h3 { font-size: 14px; }
.cc { border: 1px solid var(--line); background: var(--surface); border-radius: var(--r); padding: 10px 10px 12px; display: grid; gap: 9px; cursor: pointer; transition: border-color .15s; }
.cc:hover { border-color: var(--line-2); }
.cc.active { border-color: var(--accent); box-shadow: 0 0 0 1px var(--accent); }
.cc-head { display: flex; gap: 6px; align-items: center; }
.cc-name { font-weight: 600 !important; border-color: transparent !important; padding: 5px 7px !important; background: transparent !important; }
.cc-name:hover { border-color: var(--line-2) !important; }
.cc-name:focus { border-color: var(--accent) !important; background: var(--surface) !important; }
.x-btn { border: 0; background: transparent; color: var(--muted); width: 26px; height: 26px; border-radius: 6px; cursor: pointer; display: inline-grid; place-items: center; flex: none; }
.x-btn:hover { background: var(--bad-soft); color: var(--bad); }
.x-btn svg { width: 14px; height: 14px; }
.items { display: flex; flex-wrap: wrap; gap: 5px; }
.item { display: inline-flex; align-items: center; gap: 2px; font: 500 12px/1 var(--f-mono); padding: 4px 4px 4px 8px; border-radius: 6px; background: var(--sunken); color: var(--ink-2); border: 1px solid var(--line); }
.item button { border: 0; background: transparent; color: var(--muted); cursor: pointer; padding: 0 3px; font-size: 14px; line-height: 1; }
.item button:hover { color: var(--bad); }
.item.empty { font-family: var(--f-sans); background: transparent; border-style: dashed; padding: 4px 8px; color: var(--muted); }
.pool { display: flex; flex-wrap: wrap; gap: 5px; }
.pool button { font: 500 12px/1 var(--f-mono); padding: 6px 9px; border-radius: 6px; background: var(--surface); color: var(--ink); border: 1px dashed var(--line-2); cursor: pointer; }
.pool button:hover { border-style: solid; border-color: var(--accent); color: var(--accent); }
.rel-list { display: grid; gap: 6px; }
.rel { display: flex; align-items: center; justify-content: space-between; gap: 8px; padding: 7px 8px 7px 11px; border: 1px solid var(--line); border-radius: 8px; font-size: 13px; background: var(--surface); }
.rel .arrow { color: var(--muted); padding-inline: 4px; }
.rel-form { display: grid; grid-template-columns: minmax(0, 1fr) auto minmax(0, 1fr) auto; gap: 6px; align-items: center; }
.rel-form.mod { grid-template-columns: minmax(0, 1fr) minmax(0, 1.3fr) auto; }
.rel-form span { color: var(--muted); }
.empty-line { font-size: 13px; color: var(--muted); padding: 4px 2px; }
.step-next { display: flex; justify-content: flex-end; gap: 10px; flex-wrap: wrap; align-items: center; }

/* exports */
.exp-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 12px; }
.exp { border: 1px solid var(--line); border-radius: var(--r-lg); padding: 16px; background: var(--surface); display: grid; gap: 8px; align-content: start; }
.exp h3 { font-size: 15px; }
.exp .fmt { font: 500 11px/1 var(--f-mono); color: var(--accent); letter-spacing: .06em; }
.textout { background: var(--surface); border: 1px solid var(--line); border-radius: var(--r); padding: 16px 18px; font-size: 14px; line-height: 1.75; max-width: 92ch; color: var(--ink-2); }
.help pre { margin: 0; background: var(--sunken); padding: 12px 14px; border-radius: var(--r); overflow-x: auto; font: 12.5px/1.7 var(--f-mono); color: var(--ink-2); }
.toast { position: fixed; left: 50%; transform: translateX(-50%); bottom: calc(20px + env(safe-area-inset-bottom, 0px)); background: var(--ink); color: var(--bg); padding: 10px 16px; border-radius: 10px; font-size: 13.5px; z-index: 80; max-width: calc(100% - 32px); display: flex; gap: 14px; align-items: center; }
.toast button { background: transparent; border: 0; color: var(--bg); font: 600 13px var(--f-sans); text-decoration: underline; cursor: pointer; padding: 0; }
.rel-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(290px, 1fr)); gap: 16px; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0; }

.paper.canvas.tall { height: 640px; }
@media (max-width: 700px) { .paper.canvas { height: 440px; } .paper.canvas.tall { height: 480px; } }
.zoombar { position: absolute; right: 12px; bottom: 12px; display: flex; align-items: center; background: #ffffff; border: 1px solid #dfe3eb; border-radius: 8px; box-shadow: 0 2px 10px rgba(40,20,20,.08); overflow: hidden; z-index: 2; font-family: var(--f-sans); }
.zoombar button { border: 0; background: transparent; color: #1c1b1f; font: 600 15px/1 var(--f-sans); min-width: 36px; height: 34px; padding: 0 10px; cursor: pointer; }
.zoombar button + button { border-left: 1px solid #e6e8ee; }
.zoombar button:hover { background: #eef3fe; color: #2563eb; }
.zoombar .zlabel { font-size: 12.5px; min-width: 56px; font-variant-numeric: tabular-nums; }
.selbar { display: flex; flex-wrap: wrap; align-items: center; gap: 8px 12px; padding: 8px 12px; border: 1px solid var(--accent-line); background: var(--accent-soft); border-radius: var(--r); font-size: 14px; }
.selbar b { font-size: 15px; color: var(--accent); font-weight: 600; }
.selbar .sep { width: 1px; height: 20px; background: var(--accent-line); }
.selbar .lbl { color: var(--ink-2); font-size: 13px; }
.selbar .grow { flex: 1; }
.selbar .seg { background: var(--surface); }
.tab.done[aria-selected="true"] .dot { color: var(--accent-ink); }
.brand-mark { width: 30px; height: 30px; }