:root {
  --bg: #f4f5f7;
  --surface: #ffffff;
  --surface-2: #eef0f3;
  --border: #d5d9e0;
  --text: #1c2330;
  --muted: #5e6878;
  --accent: #c8102e;          /* CompTIA-ish red */
  --accent-soft: #fbe7ea;
  --focus: #2d6cdf;
  --ok: #1f8a4c;
  --ok-soft: #e3f4ea;
  --bad: #c4332b;
  --bad-soft: #fbe8e6;
  --warn: #b7791f;
  --token: #e8eefc;
  --token-border: #9db4ea;
  --term-bg: #0c0c0c;
  --term-text: #cccccc;
  --shadow: 0 1px 2px rgba(0,0,0,.06), 0 4px 14px rgba(0,0,0,.06);
  --radius: 10px;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #12151b; --surface: #1b2029; --surface-2: #232a35; --border: #343d4c;
    --text: #e6e9ef; --muted: #9aa4b5; --accent: #ff5a6e; --accent-soft: #3a1e25;
    --focus: #6b9cff; --ok: #4cc283; --ok-soft: #173326; --bad: #ff6b60; --bad-soft: #3b1d1b;
    --warn: #e0a84a; --token: #23314d; --token-border: #4d6aa8; --shadow: 0 1px 2px rgba(0,0,0,.4);
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #12151b; --surface: #1b2029; --surface-2: #232a35; --border: #343d4c;
  --text: #e6e9ef; --muted: #9aa4b5; --accent: #ff5a6e; --accent-soft: #3a1e25;
  --focus: #6b9cff; --ok: #4cc283; --ok-soft: #173326; --bad: #ff6b60; --bad-soft: #3b1d1b;
  --warn: #e0a84a; --token: #23314d; --token-border: #4d6aa8; --shadow: 0 1px 2px rgba(0,0,0,.4);
  color-scheme: dark;
}

* { box-sizing: border-box; }
html, body { margin: 0; }
body {
  background: var(--bg); color: var(--text);
  font: 15px/1.5 "Segoe UI", system-ui, -apple-system, Roboto, sans-serif;
}
button, input, select { font: inherit; color: inherit; }
img { max-width: 100%; display: block; }
a { color: var(--focus); }
:focus-visible { outline: 2px solid var(--focus); outline-offset: 2px; }
h1, h2, h3, h4 { line-height: 1.25; margin: 0 0 .5em; }
.muted { color: var(--muted); }
.small { font-size: 13px; }

/* ---------- top bar ---------- */
.topbar {
  position: sticky; top: 0; z-index: 20;
  display: flex; align-items: center; gap: 12px;
  padding: 8px 16px; background: var(--surface); border-bottom: 1px solid var(--border);
}
.brand { display: flex; align-items: center; gap: 8px; background: none; border: 0; cursor: pointer; padding: 4px; }
.logo { background: var(--accent); color: #fff; font-weight: 700; border-radius: 6px; padding: 2px 7px; font-size: 13px; letter-spacing: .5px; }
.brand-text { font-weight: 600; }
.brand-text small { color: var(--muted); font-weight: 400; margin-left: 4px; }
.topbar-mid { flex: 1; display: flex; justify-content: center; align-items: center; gap: 10px; min-width: 0; }
.icon-btn { background: var(--surface-2); border: 1px solid var(--border); border-radius: 8px; width: 34px; height: 34px; cursor: pointer; }
.timer { font-variant-numeric: tabular-nums; font-weight: 600; padding: 3px 10px; border-radius: 6px; background: var(--surface-2); border: 1px solid var(--border); }
.timer.low { color: #fff; background: var(--bad); border-color: var(--bad); }

main { max-width: 1240px; margin: 0 auto; padding: 20px 16px 80px; }

/* ---------- generic ---------- */
.card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); box-shadow: var(--shadow); padding: 18px; }
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 6px;
  padding: 8px 14px; border-radius: 8px; border: 1px solid var(--border);
  background: var(--surface); cursor: pointer; font-weight: 500; white-space: nowrap;
}
.btn:hover { background: var(--surface-2); }
.btn.primary { background: var(--accent); border-color: var(--accent); color: #fff; }
.btn.primary:hover { filter: brightness(1.08); }
.btn.ghost { background: transparent; }
.btn:disabled { opacity: .45; cursor: not-allowed; }
.btn.on { background: var(--accent-soft); border-color: var(--accent); }
.row { display: flex; gap: 8px; flex-wrap: wrap; align-items: center; }
.spacer { flex: 1; }
.pill { display: inline-block; font-size: 12px; padding: 1px 8px; border-radius: 99px; background: var(--surface-2); border: 1px solid var(--border); color: var(--muted); white-space: nowrap; }
.pill.messer { background: #fff3d6; border-color: #e7c66a; color: #7a5800; }
.pill.original { background: #e2f0ff; border-color: #92bdf0; color: #1d4f8a; }
:root[data-theme="dark"] .pill.messer { background: #3a3016; color: #f0d27a; border-color: #6d5a22; }
:root[data-theme="dark"] .pill.original { background: #182c45; color: #9cc5f5; border-color: #2f5482; }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .pill.messer { background: #3a3016; color: #f0d27a; border-color: #6d5a22; }
  :root:not([data-theme="light"]) .pill.original { background: #182c45; color: #9cc5f5; border-color: #2f5482; }
}

/* ---------- home ---------- */
.hero { display: grid; grid-template-columns: 1.3fr 1fr; gap: 16px; margin-bottom: 16px; }
.stats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 10px; margin: 12px 0 4px; }
.stat { background: var(--surface-2); border-radius: 8px; padding: 10px 12px; }
.stat b { display: block; font-size: 22px; font-variant-numeric: tabular-nums; }
.stat span { font-size: 12px; color: var(--muted); }
.modes { display: grid; grid-template-columns: repeat(3, 1fr); gap: 10px; margin-top: 14px; }
.mode { text-align: left; padding: 14px; border-radius: var(--radius); border: 1px solid var(--border); background: var(--surface); cursor: pointer; }
.mode:hover { border-color: var(--accent); }
.mode h3 { margin: 0 0 4px; font-size: 15px; }
.mode p { margin: 0; font-size: 13px; color: var(--muted); }
.mode.primary { background: var(--accent); color: #fff; border-color: var(--accent); }
.mode.primary p { color: rgba(255,255,255,.85); }
.domain-bars { display: grid; gap: 8px; }
.dbar { display: grid; grid-template-columns: 170px 1fr 48px; gap: 8px; align-items: center; font-size: 13px; }
.dbar .track { height: 10px; background: var(--surface-2); border-radius: 99px; overflow: hidden; border: 1px solid var(--border); }
.dbar .fill { height: 100%; background: var(--ok); }
.tips { margin: 0; padding-left: 18px; font-size: 13.5px; }
.tips li { margin-bottom: 6px; }

.filters { display: flex; gap: 8px; flex-wrap: wrap; align-items: center; margin-bottom: 10px; }
.filters select, .filters input { padding: 6px 8px; border-radius: 8px; border: 1px solid var(--border); background: var(--surface); }
.bank { width: 100%; border-collapse: collapse; font-size: 14px; }
.bank th { text-align: left; font-weight: 600; color: var(--muted); font-size: 12px; text-transform: uppercase; letter-spacing: .4px; padding: 8px; border-bottom: 1px solid var(--border); }
.bank td { padding: 9px 8px; border-bottom: 1px solid var(--border); vertical-align: middle; }
.bank tr.q-row { cursor: pointer; }
.bank tr.q-row:hover td { background: var(--surface-2); }
.score-chip { font-variant-numeric: tabular-nums; font-weight: 600; }
.score-chip.good { color: var(--ok); } .score-chip.mid { color: var(--warn); } .score-chip.poor { color: var(--bad); }
.box-dots { letter-spacing: 2px; color: var(--ok); white-space: nowrap; }
.box-dots .off { color: var(--border); }

/* ---------- question view ---------- */
.qwrap { display: grid; grid-template-columns: 1fr; gap: 14px; }
.qhead { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; }
.qhead h2 { margin: 0; font-size: 19px; }
.prompt { font-size: 16px; margin: 6px 0 0; }
.prompt ul, .prompt ol { margin: 6px 0; padding-left: 22px; }
.exam-nav { display: flex; gap: 6px; flex-wrap: wrap; }
.exam-nav button { width: 36px; height: 34px; border-radius: 6px; border: 1px solid var(--border); background: var(--surface); cursor: pointer; font-weight: 600; position: relative; }
.exam-nav button.cur { border-color: var(--accent); box-shadow: inset 0 0 0 1px var(--accent); }
.exam-nav button.done { background: var(--surface-2); }
.exam-nav button.flag::after { content: "⚑"; position: absolute; top: -8px; right: -5px; color: var(--warn); font-size: 13px; }
.actions { display: flex; gap: 8px; flex-wrap: wrap; align-items: center; position: sticky; bottom: 0; padding: 12px 0; background: linear-gradient(transparent, var(--bg) 30%); z-index: 5; }
.result-banner { border-radius: var(--radius); padding: 12px 16px; font-weight: 600; display: flex; gap: 12px; align-items: center; flex-wrap: wrap; }
.result-banner.good { background: var(--ok-soft); color: var(--ok); border: 1px solid var(--ok); }
.result-banner.mid { background: #fff6e0; color: #8a5a00; border: 1px solid #e3b44c; }
.result-banner.poor { background: var(--bad-soft); color: var(--bad); border: 1px solid var(--bad); }
:root[data-theme="dark"] .result-banner.mid { background: #3a2e12; color: #f0c66a; }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .result-banner.mid { background: #3a2e12; color: #f0c66a; } }
.explain { background: var(--surface-2); border-radius: 8px; padding: 12px 14px; font-size: 14px; }
.explain h4 { margin-bottom: 4px; }
.source { font-size: 12.5px; color: var(--muted); }

.exhibit { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 12px; overflow-x: auto; }
.exhibit-title { font-size: 12px; text-transform: uppercase; letter-spacing: .5px; color: var(--muted); margin-bottom: 6px; font-weight: 600; }
.banner-img { max-height: 620px; width: auto; margin: 0 auto; border-radius: 6px; background: #fff; }
.exhibit table { border-collapse: collapse; font-size: 13.5px; width: 100%; }
.exhibit th, .exhibit td { border: 1px solid var(--border); padding: 5px 8px; text-align: left; }
.exhibit th { background: var(--surface-2); }

/* tokens & drop zones */
.tok {
  display: inline-flex; align-items: center; gap: 6px; flex-direction: column;
  padding: 6px 10px; border-radius: 7px; background: var(--token); border: 1px solid var(--token-border);
  cursor: grab; user-select: none; touch-action: none; font-size: 14px; line-height: 1.25; text-align: center;
  max-width: 100%;
}
.tok:hover { filter: brightness(.97); }
.tok.sel { outline: 2px solid var(--accent); outline-offset: 1px; }
.tok img { width: 120px; height: auto; border-radius: 4px; pointer-events: none; }
.tok.has-img { padding: 4px; font-weight: 700; }
.tok.ghost { position: fixed; z-index: 1000; pointer-events: none; opacity: .92; box-shadow: 0 8px 22px rgba(0,0,0,.25); transform: rotate(-1.5deg); }
.tok.dragging-src { opacity: .35; }
.locked .tok { cursor: default; }

.match-grid { display: grid; grid-template-columns: minmax(0, 1fr) minmax(220px, 340px); gap: 16px; align-items: start; }
.pools { position: sticky; top: 64px; display: grid; gap: 12px; }
.pool { background: var(--surface); border: 1px dashed var(--border); border-radius: var(--radius); padding: 10px; min-height: 60px; }
.pool h4 { font-size: 12px; text-transform: uppercase; letter-spacing: .5px; color: var(--muted); margin: 0 0 8px; }
.pool .toks { display: flex; flex-wrap: wrap; gap: 6px; }
.pool.over, .drop.over, .bucket.over, .order-item.over { border-color: var(--accent); background: var(--accent-soft); }
.pool .empty { font-size: 13px; color: var(--muted); }

.slots { display: grid; gap: 10px; }
.slot { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 10px 12px; display: grid; grid-template-columns: auto 1fr; gap: 12px; align-items: center; }
.slot.no-img { grid-template-columns: 1fr; }
.slot .slot-img { width: 190px; border-radius: 6px; background: #fff; }
.slot .slot-label { font-weight: 500; }
.slot .slot-label .letter { display: inline-block; min-width: 26px; text-align: center; font-weight: 700; background: var(--surface-2); border: 1px solid var(--border); border-radius: 5px; margin-right: 8px; }
.drops { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 6px; }
.drop {
  min-height: 40px; min-width: 170px; flex: 1; display: flex; align-items: center; justify-content: center; flex-wrap: wrap; gap: 4px;
  border: 2px dashed var(--border); border-radius: 8px; padding: 4px; background: var(--surface-2); cursor: pointer;
}
.drop .ph { font-size: 12.5px; color: var(--muted); }
.drop.ok { border-style: solid; border-color: var(--ok); background: var(--ok-soft); }
.drop.bad { border-style: solid; border-color: var(--bad); background: var(--bad-soft); }
.fix { font-size: 13px; color: var(--ok); margin-top: 6px; }
.why { font-size: 13px; color: var(--muted); margin-top: 6px; border-left: 3px solid var(--border); padding-left: 8px; }

/* ordering */
.order-list { list-style: none; margin: 0; padding: 0; display: grid; gap: 8px; max-width: 720px; }
.order-item { display: grid; grid-template-columns: 70px 1fr auto; gap: 10px; align-items: center; background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 6px 8px; }
.order-item .pos { font-weight: 700; color: var(--muted); font-size: 13px; text-align: center; }
.order-item .tok { flex-direction: row; justify-content: flex-start; width: 100%; padding: 8px 10px; text-align: left; }
.order-item .tok .grip { color: var(--muted); margin-left: auto; }
.order-item.ok { border-color: var(--ok); background: var(--ok-soft); }
.order-item.bad { border-color: var(--bad); background: var(--bad-soft); }
.order-item .mv { display: flex; gap: 4px; }
.order-item .mv button { width: 30px; height: 30px; border-radius: 6px; border: 1px solid var(--border); background: var(--surface-2); cursor: pointer; }
.order-item .fix, .order-item .why { grid-column: 2 / -1; margin-top: 0; }
.swatch { width: 46px; height: 16px; border-radius: 3px; border: 1px solid rgba(0,0,0,.25); flex: none; }

/* categorize */
.cat-pool { margin-bottom: 12px; }
.buckets { display: grid; grid-template-columns: repeat(auto-fit, minmax(210px, 1fr)); gap: 12px; }
.bucket { background: var(--surface); border: 2px dashed var(--border); border-radius: var(--radius); padding: 10px; min-height: 140px; }
.bucket h4 { margin: 0 0 8px; font-size: 14px; text-align: center; }
.bucket .toks { display: flex; flex-direction: column; gap: 6px; }
.bucket .tok { width: 100%; }
.tok.ok { background: var(--ok-soft); border-color: var(--ok); }
.tok.bad { background: var(--bad-soft); border-color: var(--bad); }
.cat-review { margin-top: 12px; display: grid; gap: 4px; font-size: 13.5px; }

/* fill */
.blanks { display: grid; gap: 10px; }
.blank { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 10px 12px; display: grid; grid-template-columns: 1fr minmax(160px, 260px); gap: 12px; align-items: center; }
.blank.has-img { grid-template-columns: 1fr; }
.blank img { max-width: 520px; width: 100%; margin: 0 auto; border-radius: 6px; background: #fff; }
.blank input, .blank select, .cfg-row input, .cfg-row select, .cli-q select {
  width: 100%; padding: 7px 9px; border-radius: 7px; border: 1px solid var(--border); background: var(--surface);
}
.blank.ok, .cfg-row.ok, .cli-q.ok { border-color: var(--ok); background: var(--ok-soft); }
.blank.bad, .cfg-row.bad, .cli-q.bad { border-color: var(--bad); background: var(--bad-soft); }
.blank .fix, .blank .why { grid-column: 1 / -1; margin: 0; }

/* config sim */
.device { border: 1px solid var(--border); border-radius: var(--radius); overflow: hidden; background: var(--surface); }
.device-bar { background: #2b3445; color: #fff; padding: 9px 14px; font-weight: 600; display: flex; gap: 10px; align-items: center; }
.device-bar .dots { display: flex; gap: 5px; } .device-bar .dots i { width: 10px; height: 10px; border-radius: 50%; background: #ff5f57; display: block; }
.device-bar .dots i:nth-child(2) { background: #febc2e; } .device-bar .dots i:nth-child(3) { background: #28c840; }
.device-body { display: grid; grid-template-columns: 190px 1fr; min-height: 300px; }
.device-nav { background: var(--surface-2); border-right: 1px solid var(--border); padding: 8px; display: flex; flex-direction: column; gap: 4px; }
.device-nav button { text-align: left; border: 0; background: none; padding: 8px 10px; border-radius: 6px; cursor: pointer; }
.device-nav button.cur { background: var(--surface); box-shadow: var(--shadow); font-weight: 600; }
.device-nav button .mk { float: right; font-size: 12px; }
.device-panel { padding: 14px 16px; display: grid; gap: 10px; align-content: start; }
.cfg-row { display: grid; grid-template-columns: 240px minmax(0, 1fr); gap: 12px; align-items: center; border: 1px solid transparent; border-radius: 8px; padding: 6px 8px; }
.cfg-row label { font-weight: 500; }
.cfg-row .hint { font-size: 12px; color: var(--muted); font-weight: 400; display: block; }
.cfg-row .fix, .cfg-row .why { grid-column: 1 / -1; margin: 0; }
.switch { display: inline-flex; align-items: center; gap: 8px; cursor: pointer; }
.switch input { width: auto; }

/* CLI */
.cli-grid { display: grid; grid-template-columns: minmax(0, 1.25fr) minmax(0, 1fr); gap: 16px; align-items: start; }
.terminal { background: var(--term-bg); color: var(--term-text); border-radius: var(--radius); font: 13.5px/1.45 Consolas, "Cascadia Mono", "Courier New", monospace; overflow: hidden; border: 1px solid #333; }
.terminal .tbar { background: #1f1f1f; color: #ddd; padding: 6px 12px; font: 12px "Segoe UI", sans-serif; display: flex; justify-content: space-between; }
.terminal .tbody { padding: 10px 12px; height: 460px; overflow-y: auto; white-space: pre-wrap; word-break: break-word; cursor: text; }
.terminal .inrow { display: flex; }
.terminal input { flex: 1; background: transparent; border: 0; outline: 0; color: var(--term-text); font: inherit; padding: 0; }
.cmd-hints { font-size: 12.5px; margin-top: 6px; color: var(--muted); }
.cmd-hints code { background: var(--surface-2); padding: 1px 5px; border-radius: 4px; cursor: pointer; }
.cli-qs { display: grid; gap: 10px; }
.cli-q { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 10px 12px; }
.cli-q p { margin: 0 0 6px; font-weight: 500; }

/* diagram exhibit */
.net-diagram { display: grid; gap: 14px; justify-items: center; font-size: 13px; padding: 6px; }
.net-diagram .lane { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; justify-content: center; }
.net-diagram .node { border: 2px solid var(--border); border-radius: 8px; padding: 8px 12px; background: var(--surface-2); text-align: center; min-width: 90px; }
.net-diagram .node.q { border-color: var(--accent); background: var(--accent-soft); font-weight: 700; font-size: 16px; min-width: 52px; }
.net-diagram .arrow { color: var(--muted); }

/* results */
.results-table { width: 100%; border-collapse: collapse; }
.results-table td, .results-table th { padding: 9px 8px; border-bottom: 1px solid var(--border); text-align: left; }
.big-score { font-size: 46px; font-weight: 700; font-variant-numeric: tabular-nums; }

#toast { position: fixed; bottom: 18px; left: 50%; transform: translateX(-50%) translateY(20px); background: #222a36; color: #fff; padding: 9px 16px; border-radius: 8px; opacity: 0; transition: .2s; pointer-events: none; z-index: 2000; font-size: 14px; }
#toast.show { opacity: 1; transform: translateX(-50%); }

@media (max-width: 900px) {
  .hero { grid-template-columns: 1fr; }
  .match-grid, .cli-grid { grid-template-columns: 1fr; }
  .pools { position: static; order: -1; }
  .modes { grid-template-columns: 1fr; }
  .stats { grid-template-columns: repeat(2, 1fr); }
  .device-body { grid-template-columns: 1fr; }
  .device-nav { flex-direction: row; flex-wrap: wrap; border-right: 0; border-bottom: 1px solid var(--border); }
  .cfg-row { grid-template-columns: 1fr; gap: 4px; }
  .slot { grid-template-columns: 1fr; }
  .slot .slot-img { width: 100%; max-width: 260px; }
  .dbar { grid-template-columns: 120px 1fr 40px; }
  .bank .hide-sm { display: none; }
  .blank { grid-template-columns: 1fr; }
}