:root {
  --bg: #0b1220;
  --bg-2: #111a2e;
  --panel: #131d33;
  --panel-2: #18243f;
  --line: #243352;
  --line-2: #33466e;
  --text: #e7edf7;
  --muted: #93a4c4;
  --faint: #64769b;
  --blue: #2563eb;
  --purple: #9975e4;
  --navy: #243a5e;
  --green: #22c55e;
  --amber: #f59e0b;
  --red: #ef4444;
  --u-px: 22px;
  --rail: 26px;
}

* { box-sizing: border-box; }
html, body { margin: 0; height: 100%; }
body {
  background: radial-gradient(1200px 600px at 80% -10%, #16223c 0%, var(--bg) 60%) fixed;
  color: var(--text);
  font: 14px/1.5 ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
}

/* ---------- Topbar ---------- */
.topbar {
  display: flex; align-items: center; justify-content: space-between;
  gap: 16px; padding: 12px 20px; flex-wrap: wrap;
  border-bottom: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(20,30,52,.9), rgba(11,18,32,.6));
  position: sticky; top: 0; z-index: 20; backdrop-filter: blur(6px);
}
.brand { display: flex; align-items: center; gap: 14px; }
.logo {
  font-size: 30px; color: var(--blue);
  filter: drop-shadow(0 0 10px rgba(37,99,235,.5));
}
.topbar h1 { margin: 0; font-size: 20px; letter-spacing: .3px; font-weight: 650; }
.topbar h1 .accent { color: var(--purple); }
.tagline { margin: 0; color: var(--muted); font-size: 12.5px; }
.topbar-actions { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; }
.topbar-actions label { color: var(--muted); font-size: 12px; display: flex; align-items: center; gap: 6px; }
select, input[type=number] {
  background: var(--panel-2); color: var(--text);
  border: 1px solid var(--line-2); border-radius: 7px; padding: 5px 8px; font: inherit;
}
input[type=number] { width: 64px; }
.btn {
  background: var(--panel-2); color: var(--text); border: 1px solid var(--line-2);
  border-radius: 8px; padding: 7px 13px; font: inherit; cursor: pointer; transition: .15s;
}
.btn:hover { border-color: var(--blue); background: #1c2c4d; }
.btn-ghost { color: var(--muted); }
.btn-ghost:hover { border-color: var(--red); color: #ffd7d7; }

/* ---------- Layout ---------- */
.layout {
  display: grid;
  grid-template-columns: 300px minmax(360px, 1fr) 360px;
  gap: 18px; padding: 18px 20px; align-items: start;
  max-width: 1500px; margin: 0 auto;
}
@media (max-width: 1100px) {
  .layout { grid-template-columns: 1fr; }
  .rack-pane { order: -1; }
}

h2 { font-size: 13px; text-transform: uppercase; letter-spacing: .6px; color: var(--muted); margin: 0 0 10px; }
h3 { font-size: 13px; margin: 0 0 8px; color: var(--text); }
.hint { text-transform: none; letter-spacing: 0; color: var(--faint); font-weight: 400; font-size: 11px; }

/* ---------- Palette ---------- */
.palette {
  background: var(--panel); border: 1px solid var(--line); border-radius: 14px;
  padding: 14px; position: sticky; top: 78px; max-height: calc(100vh - 96px); overflow: auto;
}
.preset-list { display: grid; gap: 8px; margin-bottom: 18px; }
.preset {
  text-align: left; width: 100%; cursor: pointer;
  background: var(--panel-2); border: 1px solid var(--line-2); border-radius: 10px; padding: 9px 11px; color: var(--text);
}
.preset:hover { border-color: var(--purple); }
.preset b { display: block; font-size: 13px; }
.preset small { color: var(--muted); font-size: 11px; line-height: 1.35; display: block; margin-top: 2px; }

.kind-group { margin-bottom: 14px; }
.kind-head { display: flex; align-items: center; gap: 8px; margin: 0 0 7px; }
.kind-dot { width: 9px; height: 9px; border-radius: 3px; flex: none; }
.kind-head b { font-size: 12px; }
.kind-head small { color: var(--faint); font-size: 11px; }

.chip {
  display: flex; align-items: center; gap: 9px; width: 100%;
  background: var(--panel-2); border: 1px solid var(--line); border-left-width: 3px;
  border-radius: 9px; padding: 8px 10px; margin-bottom: 7px; cursor: grab; transition: .12s;
}
.chip:hover { background: #1b2942; border-color: var(--line-2); transform: translateY(-1px); }
.chip:active { cursor: grabbing; }
.chip .chip-main { flex: 1; min-width: 0; }
.chip .chip-name { font-size: 12.5px; font-weight: 550; }
.chip .chip-meta { font-size: 10.5px; color: var(--muted); }
.chip .chip-u { font-size: 11px; color: var(--faint); font-variant-numeric: tabular-nums; flex: none; }

/* ---------- Rack ---------- */
.rack-pane { display: flex; justify-content: center; }
.rack-frame {
  background: var(--panel); border: 1px solid var(--line); border-radius: 14px; padding: 16px 18px 20px;
}
.rack-label { text-align: center; color: var(--muted); font-size: 12px; margin-bottom: 10px; letter-spacing: .4px; }
.rack {
  position: relative;
  border: 2px solid var(--line-2); border-radius: 8px;
  background:
    repeating-linear-gradient(0deg, transparent 0, transparent calc(var(--u-px) - 1px), rgba(255,255,255,.04) var(--u-px)),
    linear-gradient(180deg, #0c1426, #0a111f);
  padding: 0 var(--rail);
  box-shadow: inset 0 0 30px rgba(0,0,0,.5);
}
.rack.drop-active { border-color: var(--blue); box-shadow: inset 0 0 30px rgba(37,99,235,.25); }

/* U number rails */
.rack::before, .rack::after {
  content: ""; position: absolute; top: 0; bottom: 0; width: var(--rail);
  background: repeating-linear-gradient(0deg,
     rgba(255,255,255,.05) 0, rgba(255,255,255,.05) calc(var(--u-px) - 1px),
     transparent var(--u-px), transparent var(--u-px));
}
.rack::before { left: 0; border-right: 1px solid var(--line); }
.rack::after { right: 0; border-left: 1px solid var(--line); }

.u-num {
  position: absolute; left: 0; width: var(--rail); height: var(--u-px);
  display: flex; align-items: center; justify-content: center;
  font-size: 8.5px; color: var(--faint); font-variant-numeric: tabular-nums; pointer-events: none; z-index: 1;
}

.unit {
  position: absolute; left: var(--rail); right: var(--rail);
  border-radius: 6px; border: 1px solid rgba(255,255,255,.18); border-left-width: 4px;
  display: flex; align-items: center; gap: 8px; padding: 0 10px;
  color: #fff; cursor: grab; user-select: none; overflow: hidden;
  box-shadow: 0 2px 6px rgba(0,0,0,.35); z-index: 2;
  transition: box-shadow .12s, filter .12s;
}
.unit:hover { filter: brightness(1.08); }
.unit.dragging { z-index: 50; box-shadow: 0 10px 26px rgba(0,0,0,.6); cursor: grabbing; filter: brightness(1.12); }
.unit .u-name { font-size: 12px; font-weight: 600; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.unit .u-sub { font-size: 10px; opacity: .82; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.unit .u-text { flex: 1; min-width: 0; }
.unit .u-badge {
  font-size: 9.5px; background: rgba(0,0,0,.32); border-radius: 5px; padding: 1px 6px; flex: none;
  font-variant-numeric: tabular-nums;
}
.unit .u-remove {
  flex: none; width: 18px; height: 18px; border-radius: 5px; border: none; cursor: pointer;
  background: rgba(0,0,0,.3); color: #fff; font-size: 13px; line-height: 1; opacity: 0; transition: .12s;
}
.unit:hover .u-remove { opacity: .85; }
.unit .u-remove:hover { background: var(--red); opacity: 1; }
.unit.tiny { padding: 0 6px; }
.unit.tiny .u-sub { display: none; }

.drop-ghost {
  position: absolute; left: var(--rail); right: var(--rail);
  border: 1.5px dashed var(--blue); border-radius: 6px; background: rgba(37,99,235,.15);
  z-index: 40; pointer-events: none;
}
.drop-ghost.bad { border-color: var(--red); background: rgba(239,68,68,.15); }

.rack-empty {
  position: absolute; inset: 0; display: flex; align-items: center; justify-content: center;
  color: var(--faint); font-size: 13px; text-align: center; padding: 20px; pointer-events: none;
}

/* ---------- Summary ---------- */
.summary {
  background: var(--panel); border: 1px solid var(--line); border-radius: 14px;
  padding: 16px; position: sticky; top: 78px;
}
.metric-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 9px; margin-bottom: 16px; }
.metric {
  background: var(--panel-2); border: 1px solid var(--line); border-radius: 10px; padding: 9px 11px;
}
.metric .m-val { font-size: 20px; font-weight: 650; font-variant-numeric: tabular-nums; }
.metric .m-lbl { font-size: 10.5px; color: var(--muted); text-transform: uppercase; letter-spacing: .4px; }
.metric .m-val small { font-size: 11px; color: var(--muted); font-weight: 500; }

.bars { display: grid; gap: 12px; margin-bottom: 16px; }
.bar-head { display: flex; justify-content: space-between; font-size: 11.5px; color: var(--muted); margin-bottom: 4px; }
.bar-head span:last-child { font-variant-numeric: tabular-nums; color: var(--text); }
.bar { height: 9px; background: #0c1426; border: 1px solid var(--line); border-radius: 6px; overflow: hidden; }
.bar-fill { height: 100%; width: 0; background: linear-gradient(90deg, var(--blue), var(--purple)); transition: width .25s, background .25s; }
.bar-fill.warn { background: linear-gradient(90deg, var(--amber), #fbbf24); }
.bar-fill.over { background: linear-gradient(90deg, var(--red), #f87171); }

.capability ul { list-style: none; margin: 0 0 16px; padding: 0; }
.capability li { font-size: 12px; color: var(--muted); padding: 3px 0 3px 16px; position: relative; }
.capability li::before { content: "›"; position: absolute; left: 2px; color: var(--purple); }
.capability li b { color: var(--text); font-variant-numeric: tabular-nums; }

.airgap { margin-bottom: 16px; }
.score { float: right; font-size: 12px; color: var(--muted); font-variant-numeric: tabular-nums; }
.checklist { list-style: none; margin: 0; padding: 0; display: grid; gap: 5px; }
.checklist li { font-size: 12px; display: flex; align-items: center; gap: 8px; color: var(--muted); }
.checklist .mark { width: 16px; height: 16px; border-radius: 5px; flex: none; display: grid; place-items: center; font-size: 11px; }
.checklist li.ok { color: var(--text); }
.checklist li.ok .mark { background: rgba(34,197,94,.18); color: var(--green); }
.checklist li.no .mark { background: rgba(239,68,68,.14); color: var(--red); }

.cost {
  display: flex; align-items: baseline; justify-content: space-between;
  border-top: 1px solid var(--line); padding-top: 12px;
}
.cost span { color: var(--muted); font-size: 12px; }
.cost strong { font-size: 19px; font-variant-numeric: tabular-nums; }

/* ---------- Toast ---------- */
.toast {
  position: fixed; bottom: 22px; left: 50%; transform: translateX(-50%);
  background: var(--panel-2); border: 1px solid var(--line-2); border-radius: 10px;
  padding: 10px 16px; font-size: 13px; z-index: 100; box-shadow: 0 8px 24px rgba(0,0,0,.5);
}

::-webkit-scrollbar { width: 9px; height: 9px; }
::-webkit-scrollbar-thumb { background: var(--line-2); border-radius: 6px; }
::-webkit-scrollbar-track { background: transparent; }