/* BCM cmsh Trainer — datacenter control-plane aesthetic.
 * Graphite chassis, NVIDIA green signal color, mono-forward type. */

:root {
  --bg: #101418;
  --panel: #171d23;
  --panel-edge: #262f38;
  --term-bg: #0a0d10;
  --ink: #d7dee4;
  --muted: #8494a1;
  --faint: #55636e;
  --green: #76b900;
  --green-dim: #4c7a00;
  --amber: #e0a83c;
  --red: #e2574e;
  --blue: #5aa7d0;
  --mono: ui-monospace, "SF Mono", "JetBrains Mono", Menlo, Consolas, monospace;
  --sans: system-ui, -apple-system, "Segoe UI", sans-serif;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html, body { height: 100%; }

body {
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 14px;
  display: flex;
  flex-direction: column;
}

/* ---------- top bar ---------- */

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 10px 16px;
  border-bottom: 1px solid var(--panel-edge);
  background: linear-gradient(180deg, #151a20, #111519);
  flex-wrap: wrap;
}

.brand { display: flex; align-items: baseline; gap: 10px; flex-wrap: wrap; }

.brand-mark {
  font-family: var(--mono);
  color: var(--green);
  font-weight: 700;
  font-size: 16px;
}

.brand-name {
  font-family: var(--mono);
  font-size: 16px;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.brand-sub {
  color: var(--muted);
  font-size: 12px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.topbar-right { display: flex; align-items: center; gap: 10px; }

.chip {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  font-family: var(--mono);
  font-size: 12px;
  color: var(--muted);
  background: var(--term-bg);
  border: 1px solid var(--panel-edge);
  border-radius: 999px;
  padding: 4px 12px;
}

.chip-warn { color: var(--amber); border-color: #5c4a1e; }
.hidden { display: none !important; }

.led {
  width: 8px; height: 8px; border-radius: 50%;
  background: var(--faint);
  flex: none;
}
.led-up   { background: var(--green); box-shadow: 0 0 6px var(--green); }
.led-mod  { background: var(--amber); box-shadow: 0 0 6px var(--amber); }
.led-down { background: var(--red); }
.led-boot { background: var(--amber); box-shadow: 0 0 6px var(--amber); animation: blink 1s steps(2) infinite; }

@keyframes blink { 50% { opacity: 0.25; } }
@media (prefers-reduced-motion: reduce) {
  .led-boot { animation: none; }
}

.btn {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--ink);
  background: var(--panel);
  border: 1px solid var(--panel-edge);
  border-radius: 6px;
  padding: 5px 12px;
  cursor: pointer;
}
.btn:hover { border-color: var(--muted); }
.btn:focus-visible { outline: 2px solid var(--green); outline-offset: 1px; }

/* ---------- layout ---------- */

.layout {
  flex: 1;
  display: grid;
  grid-template-columns: 1fr 380px;
  gap: 14px;
  padding: 14px;
  min-height: 0;
}

/* ---------- terminal ---------- */

.term-wrap {
  display: flex;
  flex-direction: column;
  min-width: 0;
  min-height: 0;
  border: 1px solid var(--panel-edge);
  border-radius: 10px;
  overflow: hidden;
  background: var(--term-bg);
}

.term-titlebar {
  display: flex;
  justify-content: space-between;
  gap: 10px;
  padding: 7px 14px;
  font-family: var(--mono);
  font-size: 11px;
  color: var(--muted);
  background: var(--panel);
  border-bottom: 1px solid var(--panel-edge);
}

.term-titlebar-hint { color: var(--faint); }

.term {
  flex: 1;
  overflow-y: auto;
  padding: 14px 16px 18px;
  font-family: var(--mono);
  font-size: 13px;
  line-height: 1.5;
  cursor: text;
}

.term-line { white-space: pre-wrap; word-break: break-all; }

.term-line.err   { color: var(--red); }
.term-line.ok    { color: var(--green); }
.term-line.muted { color: var(--muted); }
.term-line.event { color: var(--blue); font-style: italic; }
.term-line.echo  { color: var(--ink); }
.term-line.echo .term-prompt { user-select: text; }

.st-up    { color: var(--green); font-weight: 700; }
.st-down  { color: var(--red); font-weight: 700; }
.st-boot  { color: var(--amber); font-weight: 700; }

.term-prompt { color: var(--green); font-weight: 700; white-space: pre; }

.term-input-row { display: flex; align-items: baseline; }

#term-input {
  flex: 1;
  background: transparent;
  border: none;
  outline: none;
  color: var(--ink);
  font: inherit;
  caret-color: var(--green);
  min-width: 40px;
}

/* ---------- side panels ---------- */

.side {
  display: flex;
  flex-direction: column;
  gap: 14px;
  min-height: 0;
  overflow-y: auto;
}

.panel {
  background: var(--panel);
  border: 1px solid var(--panel-edge);
  border-radius: 10px;
  padding: 14px;
}

.panel-title {
  font-family: var(--mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 12px;
  display: flex;
  justify-content: space-between;
  align-items: baseline;
}

.panel-title-note {
  font-weight: 400;
  letter-spacing: 0.06em;
  color: var(--green);
}

/* ---------- rack ---------- */

.rack {
  border: 1px solid var(--panel-edge);
  border-radius: 6px;
  background: var(--term-bg);
  padding: 6px;
  display: flex;
  flex-direction: column;
  gap: 3px;
}

.ru {
  display: flex;
  align-items: center;
  gap: 9px;
  font-family: var(--mono);
  font-size: 12px;
  padding: 5px 9px;
  border: 1px solid #1d242b;
  border-radius: 4px;
  background: linear-gradient(180deg, #14191e, #10151a);
}

.ru-head { border-color: #2c3a20; }
.ru-name { flex: 1; }
.ru-tag {
  font-size: 10px;
  color: var(--muted);
  border: 1px solid var(--panel-edge);
  border-radius: 3px;
  padding: 1px 6px;
}
.ru-tag-gpu { color: var(--green); border-color: var(--green-dim); }
.ru-status { font-size: 10px; color: var(--faint); width: 62px; text-align: right; }

/* ---------- lessons ---------- */

.lesson {
  border: 1px solid var(--panel-edge);
  border-radius: 8px;
  margin-bottom: 8px;
  background: var(--term-bg);
  overflow: hidden;
}

.lesson-head {
  width: 100%;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 12px;
  background: none;
  border: none;
  color: var(--ink);
  font-family: var(--sans);
  font-size: 13px;
  font-weight: 600;
  text-align: left;
  cursor: pointer;
}
.lesson-head:focus-visible { outline: 2px solid var(--green); outline-offset: -2px; }

.lesson-num {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--faint);
  width: 18px;
  flex: none;
}

.lesson-check { margin-left: auto; font-family: var(--mono); font-size: 12px; color: var(--faint); }
.lesson.done .lesson-check { color: var(--green); }
.lesson.active { border-color: var(--green-dim); }

.lesson-body { padding: 2px 12px 12px; display: none; }
.lesson.open .lesson-body { display: block; }

.lesson-blurb { color: var(--muted); font-size: 12px; margin-bottom: 10px; line-height: 1.5; }

.step {
  display: flex;
  gap: 9px;
  padding: 7px 0;
  border-top: 1px solid #1a2128;
  font-size: 12.5px;
  line-height: 1.5;
  color: var(--muted);
}
.step.current { color: var(--ink); }
.step.done { color: var(--faint); text-decoration: none; }

.step-box {
  font-family: var(--mono);
  flex: none;
  width: 16px; height: 16px;
  margin-top: 2px;
  border: 1px solid var(--panel-edge);
  border-radius: 3px;
  color: var(--green);
  font-size: 11px;
  line-height: 14px;
  text-align: center;
}
.step.done .step-box { border-color: var(--green-dim); background: rgba(118, 185, 0, 0.12); }
.step.current .step-box { border-color: var(--green); }

.step-hint {
  display: block;
  font-family: var(--mono);
  font-size: 11.5px;
  color: var(--green);
  margin-top: 3px;
  cursor: pointer;
  background: none;
  border: none;
  padding: 0;
  text-align: left;
}
.step-hint:hover { text-decoration: underline; }
.step-hint-cmd { color: var(--amber); font-family: var(--mono); font-size: 11.5px; display: block; margin-top: 3px; cursor: pointer; }
.step-hint-cmd:hover { text-decoration: underline; }

/* Start / restart buttons shared by lessons and labs. */
.scenario-actions { display: flex; gap: 8px; margin-top: 10px; }
.btn-start, .btn-hint {
  font-size: 11.5px;
  padding: 5px 12px;
}
.btn-start { color: var(--green); border-color: var(--green-dim); }
.btn-start:hover { border-color: var(--green); }
.lesson-title, .lab-title { flex: 1; }

/* ---------- troubleshooting labs ---------- */

.panel-lead {
  color: var(--muted);
  font-size: 12px;
  line-height: 1.5;
  margin: -4px 0 12px;
}

.lab {
  border: 1px solid var(--panel-edge);
  border-radius: 8px;
  margin-bottom: 8px;
  background: var(--term-bg);
  overflow: hidden;
}
.lab.active { border-color: var(--amber); }
.lab.solved { border-color: var(--green-dim); }

.lab-head {
  width: 100%;
  display: flex;
  align-items: center;
  gap: 9px;
  padding: 10px 12px;
  background: none;
  border: none;
  color: var(--ink);
  font-family: var(--sans);
  font-size: 13px;
  font-weight: 600;
  text-align: left;
  cursor: pointer;
}
.lab-head:focus-visible { outline: 2px solid var(--green); outline-offset: -2px; }

.lab-diff {
  font-family: var(--mono);
  font-size: 9.5px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 2px 7px;
  border-radius: 3px;
  border: 1px solid var(--panel-edge);
  flex: none;
}
.diff-beginner     { color: var(--green); border-color: var(--green-dim); }
.diff-intermediate { color: var(--amber); border-color: #5c4a1e; }
.diff-advanced     { color: var(--red); border-color: #5c2420; }
.diff-drill        { color: var(--blue); border-color: #1f3f52; }

.btn-drill-cta {
  color: var(--blue);
  border-color: #1f3f52;
  margin-bottom: 12px;
}
.btn-drill-cta:hover { border-color: var(--blue); }

.drill-mystery {
  border-style: dashed;
  border-color: #1f3f52;
}
.drill-mystery .lab-head { cursor: default; }

.lab-check { margin-left: auto; font-family: var(--mono); font-size: 11px; color: var(--faint); flex: none; }
.lab.active .lab-check { color: var(--amber); }
.lab.solved .lab-check { color: var(--green); }

.lab-body { padding: 2px 12px 12px; display: none; }
.lab.open .lab-body { display: block; }

.lab-briefing { color: var(--muted); font-size: 12px; line-height: 1.55; margin-bottom: 10px; }

.lab-goals {
  border-top: 1px solid #1a2128;
  padding-top: 9px;
  display: flex;
  flex-direction: column;
  gap: 5px;
}
.goal {
  display: flex;
  gap: 8px;
  font-size: 12px;
  line-height: 1.4;
  color: var(--muted);
}
.goal.done { color: var(--ink); }
.goal-box {
  font-family: var(--mono);
  color: var(--faint);
  flex: none;
}
.goal.done .goal-box { color: var(--green); }

.lab-hints {
  margin: 10px 0 0;
  padding-left: 18px;
  color: var(--muted);
  font-size: 11.5px;
  line-height: 1.6;
}
.lab-hints li { margin-bottom: 4px; }
.lab-hints li::marker { color: var(--amber); }

.btn-block { width: 100%; margin-top: 10px; }

.refs-panel { display: flex; flex-direction: column; }

.cheatsheet { margin-top: 0; }
.cheatsheet summary {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
  cursor: pointer;
}
.cheatsheet pre {
  margin-top: 8px;
  font-family: var(--mono);
  font-size: 11.5px;
  line-height: 1.7;
  color: var(--muted);
  background: var(--term-bg);
  border: 1px solid var(--panel-edge);
  border-radius: 6px;
  padding: 10px 12px;
  overflow-x: auto;
}

/* ---------- responsive ---------- */

@media (max-width: 900px) {
  .layout { grid-template-columns: 1fr; grid-template-rows: 60vh auto; }
  .side { overflow-y: visible; }
  .brand-sub { display: none; }
}