:root {
  --bg: #0b0f17;
  --panel: #131a26;
  --panel-alt: #1b2434;
  --border: #2a364d;
  --accent: #00e5a3;
  --accent-glow: rgba(0, 229, 163, 0.18);
  --cyan: #38bdf8;
  --cyan-glow: rgba(56, 189, 248, 0.2);
  --gold: #f59e0b;
  --danger: #ef4444;
  --danger-glow: rgba(239, 68, 68, 0.2);
  --text: #f1f5f9;
  --muted: #94a3b8;
  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --mono: 'JetBrains Mono', 'Fira Code', Consolas, monospace;
}
* { box-sizing: border-box; margin: 0; padding: 0; }
body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  line-height: 1.65;
  font-size: 16px;
}
a { color: var(--cyan); text-decoration: none; transition: color 0.15s; }
a:hover { color: #7dd3fc; text-decoration: underline; }
.container { max-width: 1160px; margin: 0 auto; padding: 0 20px; }

/* Header & Nav */
.site-header {
  background: rgba(19, 26, 38, 0.92);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
}
.nav-wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 0;
  flex-wrap: wrap;
  gap: 12px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  font-size: 1.15rem;
  color: var(--text);
  text-decoration: none !important;
}
.brand-badge {
  background: linear-gradient(135deg, #00e5a3, #38bdf8);
  color: #0b0f17;
  font-weight: 900;
  padding: 4px 9px;
  border-radius: 6px;
  font-size: 0.82rem;
}
.nav-links {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}
.nav-links a {
  color: var(--muted);
  font-size: 0.9rem;
  font-weight: 600;
  padding: 6px 12px;
  border-radius: 6px;
  text-decoration: none;
}
.nav-links a:hover, .nav-links a.active {
  color: var(--text);
  background: var(--panel-alt);
}

/* Hero Section */
.hero {
  padding: 36px 0 24px;
  text-align: center;
}
.version-pill {
  display: inline-block;
  background: var(--cyan-glow);
  color: #7dd3fc;
  border: 1px solid rgba(56, 189, 248, 0.45);
  font-size: 0.82rem;
  font-weight: 700;
  padding: 4px 12px;
  border-radius: 999px;
  margin-bottom: 12px;
}
h1 {
  font-size: clamp(1.85rem, 3.6vw, 2.65rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 12px;
  color: #ffffff;
}
.hero-sub {
  max-width: 780px;
  margin: 0 auto 22px;
  color: var(--muted);
  font-size: 1.05rem;
}

/* Main Diagnostic Grid */
.calc-grid {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 22px;
  margin-bottom: 40px;
}
@media (max-width: 900px) {
  .calc-grid { grid-template-columns: 1fr; }
}
.card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 22px;
}
.card-title {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin-bottom: 16px;
}
@media (max-width: 560px) {
  .form-row { grid-template-columns: 1fr; }
}
label.field-label {
  display: block;
  font-size: 0.84rem;
  color: var(--muted);
  font-weight: 600;
  margin-bottom: 6px;
}
select, input[type="number"], input[type="text"], textarea {
  width: 100%;
  background: #0b0f17;
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 10px 12px;
  font-size: 0.95rem;
  font-weight: 600;
  font-family: var(--font);
}
textarea { font-family: var(--mono); resize: vertical; }

/* Interactive Test Zones */
.test-zone {
  background: radial-gradient(circle at center, rgba(56, 189, 248, 0.1), #0b0f17 75%);
  border: 2px dashed var(--cyan);
  border-radius: 12px;
  padding: 28px 20px;
  text-align: center;
  cursor: pointer;
  user-select: none;
  transition: all 0.15s;
  min-height: 175px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  margin-bottom: 16px;
  position: relative;
  overflow: hidden;
}
.test-zone:hover, .test-zone.active {
  border-style: solid;
  border-color: var(--accent);
  box-shadow: 0 0 24px var(--accent-glow);
}
.test-zone.fault {
  border-color: var(--danger);
  background: radial-gradient(circle at center, rgba(239, 68, 68, 0.2), #0b0f17 75%);
}
.zone-title {
  font-size: 1.35rem;
  font-weight: 800;
  color: #ffffff;
  margin-bottom: 6px;
}
.zone-sub {
  font-size: 0.9rem;
  color: var(--muted);
}

/* Telemetry Stats */
.summary-badges {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px;
  margin-bottom: 16px;
}
.stat-box {
  background: var(--panel-alt);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 12px;
  text-align: center;
}
.stat-label {
  font-size: 0.75rem;
  color: var(--muted);
  text-transform: uppercase;
  font-weight: 700;
}
.stat-val {
  font-size: 1.4rem;
  font-weight: 800;
  color: var(--accent);
  font-family: var(--mono);
  margin-top: 2px;
}
.stat-val.danger { color: var(--danger); }
.stat-val.warn { color: var(--gold); }

/* Status Banner */
.status-banner {
  padding: 10px 14px;
  border-radius: 8px;
  font-size: 0.88rem;
  font-weight: 700;
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.status-banner.safe {
  background: var(--accent-glow);
  border: 1px solid rgba(0, 229, 163, 0.45);
  color: var(--accent);
}
.status-banner.danger {
  background: var(--danger-glow);
  border: 1px solid rgba(239, 68, 68, 0.5);
  color: #f87171;
}

/* Event Log & Buttons */
.log-box {
  background: #0b0f17;
  border: 1px solid var(--border);
  border-radius: 8px;
  height: 155px;
  overflow-y: auto;
  padding: 10px;
  font-family: var(--mono);
  font-size: 0.82rem;
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.log-row {
  display: flex;
  justify-content: space-between;
  padding: 3px 6px;
  border-radius: 4px;
}
.log-row.glitch {
  background: rgba(239, 68, 68, 0.22);
  color: #fca5a5;
  font-weight: 700;
}
.action-bar {
  display: flex;
  gap: 10px;
  margin-top: 14px;
  flex-wrap: wrap;
}
.btn-action {
  flex: 1;
  background: var(--panel-alt);
  color: var(--text);
  border: 1px solid var(--border);
  padding: 10px 14px;
  border-radius: 8px;
  font-weight: 700;
  font-size: 0.88rem;
  cursor: pointer;
  transition: all 0.15s;
}
.btn-action:hover { border-color: var(--accent); color: var(--accent); }
.btn-primary {
  background: var(--accent);
  color: #0b0f17;
  border-color: var(--accent);
}
.btn-primary:hover { background: #34d399; color: #0b0f17; }

/* Keyboard Matrix */
.kb-grid {
  display: flex;
  flex-direction: column;
  gap: 6px;
  background: #0b0f17;
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 14px;
  margin-bottom: 16px;
  overflow-x: auto;
}
.kb-row {
  display: flex;
  gap: 6px;
}
.kb-key {
  background: var(--panel-alt);
  border: 1px solid var(--border);
  border-bottom: 3px solid #0f172a;
  border-radius: 6px;
  min-width: 38px;
  height: 38px;
  padding: 0 6px;
  font-size: 0.74rem;
  font-weight: 700;
  font-family: var(--mono);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--muted);
  transition: all 0.06s;
}
.kb-key.tested {
  border-color: rgba(56, 189, 248, 0.5);
  color: var(--text);
}
.kb-key.held {
  background: var(--accent);
  color: #0b0f17;
  border-color: var(--accent);
  transform: translateY(2px);
}
.kb-key.chatter {
  background: var(--danger);
  color: #ffffff;
  border-color: var(--danger);
}

/* Content Sections */
.content-section {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 30px;
  margin-bottom: 28px;
}
.content-section h2 {
  font-size: 1.55rem;
  color: #ffffff;
  margin-bottom: 14px;
  border-bottom: 1px solid var(--border);
  padding-bottom: 10px;
}
.content-section h3 {
  font-size: 1.18rem;
  color: var(--cyan);
  margin: 20px 0 8px;
}
.content-section p {
  margin-bottom: 14px;
  color: #cbd5e1;
}
.content-section ul, .content-section ol {
  margin: 0 0 16px 22px;
  color: #cbd5e1;
}
.content-section li { margin-bottom: 8px; }
code {
  background: #0b0f17;
  padding: 2px 6px;
  border-radius: 5px;
  font-family: var(--mono);
  font-size: 0.88em;
  color: var(--cyan);
}

/* Tables */
.table-wrap { overflow-x: auto; margin: 16px 0; }
table.data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.92rem;
}
table.data-table th, table.data-table td {
  border: 1px solid var(--border);
  padding: 10px 14px;
  text-align: left;
}
table.data-table th {
  background: var(--panel-alt);
  color: #ffffff;
  font-weight: 700;
}
table.data-table tr:nth-child(even) { background: rgba(255,255,255,0.02); }

/* FAQ Grid */
.faq-item {
  border-bottom: 1px solid var(--border);
  padding: 16px 0;
}
.faq-item:last-child { border-bottom: none; }
.faq-q {
  font-weight: 700;
  font-size: 1.06rem;
  color: #ffffff;
  margin-bottom: 6px;
}
.faq-a { color: #cbd5e1; margin: 0; }

/* Footer */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 36px 0;
  margin-top: 48px;
  color: var(--muted);
  font-size: 0.88rem;
}
.footer-grid {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 20px;
}