@import url('https://fonts.googleapis.com/css2?family=Big+Shoulders+Display:wght@600;800&family=IBM+Plex+Sans:wght@400;500;600&family=IBM+Plex+Mono:wght@500&display=swap');

:root {
  --ink: #15191c;
  --ink-soft: #2a3138;
  --steel: #4c5a67;
  --steel-light: #8a97a3;
  --paper: #edeae1;
  --paper-dim: #e0dccf;
  --amber: #e8a33d;
  --amber-dark: #a86a1a;
  --rust: #b6462a;
  --rust-bg: #f4ded6;
  --teal: #3f7d6b;
  --teal-bg: #dbe9e2;
  --line: rgba(21, 25, 28, 0.14);
  --shadow: 0 2px 0 rgba(21, 25, 28, 0.08);
  --font-display: 'Big Shoulders Display', sans-serif;
  --font-body: 'IBM Plex Sans', sans-serif;
  --font-mono: 'IBM Plex Mono', monospace;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-body);
  line-height: 1.55;
}

a { color: inherit; }

.wrap {
  max-width: 960px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ---------------- Nav ---------------- */

.topnav {
  position: sticky;
  top: 0;
  z-index: 20;
  background: var(--ink);
  color: var(--paper);
  border-bottom: 3px solid var(--amber);
}

.topnav .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 60px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 20px;
  letter-spacing: 0.02em;
  cursor: pointer;
  background: none;
  border: none;
  color: var(--paper);
}

.brand .bolt {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--amber);
  display: inline-block;
}

.nav-links {
  display: flex;
  gap: 22px;
  font-size: 14px;
  font-weight: 500;
}

.nav-links button {
  background: none;
  border: none;
  color: var(--steel-light);
  cursor: pointer;
  font-family: var(--font-body);
  font-size: 14px;
  padding: 6px 0;
  border-bottom: 2px solid transparent;
}

.nav-links button:hover,
.nav-links button.active {
  color: var(--paper);
  border-bottom-color: var(--amber);
}

/* ---------------- Views ---------------- */

.view { display: none; padding: 48px 0 80px; }
.view.active { display: block; }

/* ---------------- Hero ---------------- */

.hero {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 40px;
  align-items: center;
  padding-bottom: 48px;
  border-bottom: 1px solid var(--line);
  margin-bottom: 44px;
}

.eyebrow {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--rust);
  margin: 0 0 10px;
}

.hero h1 {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 46px;
  line-height: 0.98;
  margin: 0 0 18px;
  letter-spacing: -0.01em;
}

.hero p.lead {
  font-size: 16px;
  color: var(--ink-soft);
  max-width: 46ch;
  margin: 0 0 24px;
}

.btn {
  font-family: var(--font-body);
  font-weight: 600;
  font-size: 14px;
  padding: 12px 20px;
  border-radius: 3px;
  border: 1.5px solid var(--ink);
  background: var(--ink);
  color: var(--paper);
  cursor: pointer;
}

.btn:hover { background: var(--ink-soft); }

.btn.ghost {
  background: transparent;
  color: var(--ink);
}

.btn.ghost:hover { background: rgba(21,25,28,0.06); }

.btn:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}

/* gauge dial signature element */

.dial-wrap {
  display: flex;
  align-items: center;
  justify-content: center;
}

.dial {
  width: 200px;
  height: 200px;
}

.dial .needle {
  transform-origin: 100px 100px;
  animation: sweep 3.2s ease-in-out infinite alternate;
}

@keyframes sweep {
  0%   { transform: rotate(-100deg); }
  100% { transform: rotate(80deg); }
}

@media (prefers-reduced-motion: reduce) {
  .dial .needle { animation: none; transform: rotate(20deg); }
}

/* ---------------- Tag cards (signature module cards) ---------------- */

.section-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  margin-bottom: 20px;
}

.section-head h2 {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 26px;
  margin: 0;
}

.section-head .count {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--steel);
}

.tag-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
  margin-bottom: 56px;
}

.tag-card {
  position: relative;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 4px;
  padding: 20px 20px 20px 34px;
  cursor: pointer;
  box-shadow: var(--shadow);
  transition: transform 0.12s ease;
}

.tag-card:hover { transform: translateY(-2px); }

.tag-card::before {
  content: "";
  position: absolute;
  left: 14px;
  top: 20px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--paper);
  border: 1.5px solid var(--steel-light);
  box-shadow: inset 0 0 0 2px #fff;
}

.tag-card::after {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 6px;
  background: var(--steel-light);
  border-radius: 4px 0 0 4px;
}

.tag-card.done::after { background: var(--teal); }
.tag-card.progress::after { background: var(--amber); }

.tag-num {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--steel);
  letter-spacing: 0.08em;
}

.tag-card h3 {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 21px;
  margin: 6px 0 8px;
  line-height: 1.05;
}

.tag-card p {
  font-size: 13.5px;
  color: var(--ink-soft);
  margin: 0 0 14px;
}

.tag-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 12px;
}

.stamp {
  font-family: var(--font-mono);
  font-weight: 500;
  padding: 3px 8px;
  border-radius: 2px;
  border: 1px solid currentColor;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  font-size: 11px;
}

.stamp.done { color: var(--teal); }
.stamp.progress { color: var(--amber-dark); }
.stamp.new { color: var(--steel); }

/* ---------------- Module view ---------------- */

.module-head { margin-bottom: 28px; }
.module-head .tag-num { display: block; margin-bottom: 4px; }
.module-head h1 {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 34px;
  margin: 0 0 8px;
}

.step-strip {
  display: flex;
  gap: 8px;
  margin-bottom: 28px;
}

.step-pill {
  flex: 1;
  height: 6px;
  border-radius: 3px;
  background: var(--paper-dim);
}

.step-pill.on { background: var(--amber); }
.step-pill.pastdone { background: var(--steel-light); }

.concept-block {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 22px 24px;
  margin-bottom: 28px;
}

.concept-block p { margin: 0 0 14px; font-size: 15px; }
.concept-block p:last-child { margin-bottom: 0; }

/* reference content: why it matters / common mistakes / glossary */

.ref-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-bottom: 16px;
}

.ref-label {
  font-family: var(--font-mono);
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--steel);
  display: flex;
  align-items: center;
  gap: 6px;
  margin: 0 0 8px;
}

.why-matters-box {
  background: #fff;
  border: 1px solid var(--amber);
  border-left: 4px solid var(--amber-dark);
  border-radius: 4px;
  padding: 14px 16px;
}

.why-matters-box p:not(.ref-label) { font-size: 13.5px; margin: 0; color: var(--ink-soft); }
.why-matters-box .ref-label { color: var(--amber-dark); }

.mistakes-box {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 4px;
  padding: 14px 16px;
}

.mistakes-box ul { margin: 0; padding-left: 18px; font-size: 13px; color: var(--ink-soft); }
.mistakes-box li { margin-bottom: 4px; }

.glossary-box {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 14px 18px;
  margin-bottom: 28px;
}

.glossary-box summary {
  font-weight: 600;
  font-size: 14px;
  cursor: pointer;
}

#glossary-list { margin-top: 12px; display: flex; flex-direction: column; gap: 10px; }
.glossary-item dt {
  font-family: var(--font-mono);
  font-size: 12.5px;
  font-weight: 600;
  color: var(--ink);
}
.glossary-item dd { margin: 2px 0 0; font-size: 13px; color: var(--ink-soft); }

/* scenario picker */

.scenario-tabs {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin-bottom: 18px;
}

.scenario-tab {
  font-family: var(--font-body);
  font-size: 13px;
  font-weight: 500;
  padding: 8px 14px;
  border-radius: 20px;
  border: 1.5px solid var(--line);
  background: #fff;
  color: var(--steel);
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 5px;
}

.scenario-tab.active { border-color: var(--ink); color: var(--ink); background: var(--paper); }
.scenario-tab.done { border-color: var(--teal); color: var(--teal); }
.scenario-tab.done.active { background: var(--teal-bg); }
.scenario-tab .ti-check { font-size: 13px; }

/* ---------------- Equipment diagram ---------------- */

.diagram-box {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 12px 16px 4px;
  margin-bottom: 20px;
}

.diagram-box svg {
  width: 100%;
  height: auto;
  display: block;
}

.d-part rect,
.d-part circle,
.d-part path,
.d-part line,
.d-part polygon {
  stroke: var(--steel);
  stroke-width: 2;
  fill: var(--paper-dim);
  transition: stroke 0.25s ease, fill 0.25s ease, stroke-width 0.25s ease;
}

.d-part path { fill: none; stroke-width: 2.5; }

.d-part text {
  font-family: var(--font-mono);
  font-size: 10px;
  fill: var(--steel);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.d-line { stroke: var(--steel-light); stroke-width: 3; }
.d-idle { fill: var(--paper-dim); stroke: var(--steel-light); stroke-width: 2; }
.d-hole { fill: var(--paper); stroke: none; }
.d-caption { font-family: var(--font-mono); font-size: 9px; fill: var(--steel-light); text-transform: uppercase; letter-spacing: 0.04em; }
.d-readout { font-family: var(--font-mono); font-size: 14px; fill: var(--steel); }

.d-part.active rect,
.d-part.active circle,
.d-part.active path,
.d-part.active polygon {
  stroke: var(--amber-dark);
  fill: rgba(232, 163, 61, 0.28);
  stroke-width: 3;
}

.d-part.active line { stroke: var(--amber-dark); stroke-width: 3; }

.d-part.active text {
  fill: var(--amber-dark);
  font-weight: 600;
}

@media (prefers-reduced-motion: no-preference) {
  .d-part.active rect,
  .d-part.active circle,
  .d-part.active path,
  .d-part.active polygon {
    animation: partPulse 1.6s ease-in-out 1;
  }
}

@keyframes partPulse {
  0%   { stroke-width: 2; }
  35%  { stroke-width: 4.5; }
  100% { stroke-width: 3; }
}

/* gauge readouts inside sim */

.gauge-row {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 12px;
  margin-bottom: 24px;
}

.gauge {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 4px;
  padding: 12px 16px;
}

.gauge .g-label {
  font-size: 11px;
  color: var(--steel);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin: 0 0 4px;
}

.gauge .g-val {
  font-family: var(--font-mono);
  font-size: 22px;
  font-weight: 500;
  margin: 0;
}

.sim-status {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--steel);
  margin-bottom: 10px;
}

.prompt-box {
  font-size: 17px;
  font-weight: 500;
  margin: 0 0 16px;
  padding: 16px 18px;
  background: var(--ink);
  color: var(--paper);
  border-radius: 4px;
}

.options { display: flex; flex-direction: column; gap: 10px; margin-bottom: 24px; }

.opt-btn {
  text-align: left;
  background: #fff;
  border: 1.5px solid var(--line);
  border-radius: 4px;
  padding: 13px 16px;
  font-family: var(--font-body);
  font-size: 14.5px;
  font-weight: 500;
  cursor: pointer;
}

.opt-btn:hover { border-color: var(--ink); }

.log-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
  border-top: 1px solid var(--line);
  padding-top: 14px;
}

.log-row {
  font-size: 13px;
  display: flex;
  gap: 8px;
  align-items: flex-start;
}

.log-row .ico { font-size: 14px; margin-top: 1px; }
.log-row.good { color: var(--teal); }
.log-row.bad { color: var(--rust); }
.log-row.neutral { color: var(--steel); }

.result-box {
  border-radius: 6px;
  padding: 18px 20px;
  margin-top: 20px;
  font-size: 15px;
  font-weight: 500;
}

.result-box.pass { background: var(--teal-bg); color: #234f42; }
.result-box.fail { background: var(--rust-bg); color: #6b2515; }

/* quiz */

.quiz-block { margin-top: 12px; }

.quiz-q {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 18px 20px;
  margin-bottom: 16px;
}

.quiz-q .q-text { font-size: 15px; font-weight: 500; margin: 0 0 12px; }

.quiz-opt {
  display: block;
  width: 100%;
  text-align: left;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 4px;
  padding: 10px 14px;
  font-size: 14px;
  margin-bottom: 8px;
  cursor: pointer;
  font-family: var(--font-body);
}

.quiz-opt.correct { background: var(--teal-bg); border-color: var(--teal); }
.quiz-opt.wrong { background: var(--rust-bg); border-color: var(--rust); }
.quiz-opt:disabled { cursor: default; }

.quiz-explain {
  font-size: 13px;
  color: var(--ink-soft);
  margin: 8px 0 0;
  padding-top: 8px;
  border-top: 1px solid var(--line);
}

/* ---------------- Certification ---------------- */

.cert-gate {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 24px 26px;
  margin-bottom: 28px;
}

.cert-gate ul { margin: 12px 0 0; padding-left: 20px; font-size: 14px; }
.cert-gate li { margin-bottom: 6px; }
.cert-gate li.met { color: var(--teal); }
.cert-gate li.unmet { color: var(--rust); }

.cert-sheet {
  background: #fff;
  border: 3px solid var(--ink);
  border-radius: 6px;
  padding: 48px;
  text-align: center;
  margin-top: 24px;
}

.cert-sheet .eyebrow { justify-content: center; }
.cert-sheet h2 {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 30px;
  margin: 6px 0 20px;
}
.cert-sheet .cert-name {
  font-family: var(--font-display);
  font-size: 38px;
  font-weight: 800;
  border-bottom: 2px solid var(--ink);
  display: inline-block;
  padding: 0 12px 6px;
  margin-bottom: 18px;
}
.cert-sheet .cert-meta {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--steel);
}

input[type="text"] {
  font-family: var(--font-body);
  font-size: 15px;
  padding: 10px 14px;
  border: 1.5px solid var(--line);
  border-radius: 4px;
  width: 260px;
  margin-right: 10px;
}

footer.site-footer {
  border-top: 1px solid var(--line);
  padding: 24px 0;
  font-size: 12.5px;
  color: var(--steel);
  text-align: center;
}

@media print {
  .topnav, .cert-gate, .no-print { display: none !important; }
  body { background: #fff; }
  .cert-sheet { border: 3px solid #000; margin: 0; }
}

@media (max-width: 720px) {
  .hero { grid-template-columns: 1fr; }
  .tag-grid { grid-template-columns: 1fr; }
  .dial-wrap { order: -1; }
}