/* ============================================================
   exp1_components.css — Enhanced Experiment 1
   Requires: global.css (handles nav, bg-mesh, blobs, base vars)
   ============================================================ */

/* ── Local variable extensions (global.css vars are inherited) ── */
:root {
  --bg:          #eceeff;
  --surface:     rgba(255,255,255,0.55);
  --border:      rgba(255,255,255,0.6);
  --border-dark: rgba(0,0,0,0.08);
  --green:       #10B981;
  --cyan:        #06b6d4;
  --purple:      #7C3AED;
  --amber:       #F59E0B;
  --blue:        #1A56DB;
  --rose:        #F43F5E;
  --text:        #0f0f1a;
  --muted:       #475569;
  --font-mono:   'JetBrains Mono', monospace;
  --font-display: var(--lf-font-display);
  --font-body:    var(--lf-font-body);
}

body {
  margin: 0;
  background-color: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
}

/* ── Page layout ── */
.page {
  padding-top: var(--lf-main-padding-top);
  max-width: 1380px;
  margin: 0 auto;
  padding-left: 2rem;
  padding-right: 2rem;
  padding-bottom: 4rem;
  position: relative;
  z-index: 10;
}

.page-header {
  padding: 1.75rem 0 1rem;
}

.breadcrumb {
  display: flex;
  align-items: center;
  gap: .5rem;
  font-family: var(--font-mono);
  font-size: .65rem;
  color: var(--muted);
  margin-bottom: .6rem;
}

.breadcrumb .badge {
  background: rgba(26,86,219,.15);
  border: 1px solid rgba(26,86,219,.3);
  color: var(--blue);
  padding: .15rem .5rem;
  border-radius: 999px;
  font-weight: 700;
}

.page-header h1 {
  font-family: var(--font-display);
  font-size: 2.2rem;
  color: var(--text);
  margin-bottom: .35rem;
  letter-spacing: -0.03em;
}

.page-header p {
  font-size: .9rem;
  color: var(--muted);
  max-width: 600px;
}

/* ── Tab bar ── */
.tab-bar {
  display: flex;
  gap: .35rem;
  padding: .45rem;
  background: var(--surface);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--border);
  border-radius: 14px;
  margin-bottom: 1.5rem;
  flex-wrap: wrap;
  box-shadow: 0 4px 16px rgba(0,0,0,.04);
}

.tab-btn {
  display: flex;
  align-items: center;
  gap: .4rem;
  padding: .45rem .9rem;
  border: none;
  background: transparent;
  border-radius: 9px;
  font-family: var(--font-mono);
  font-size: .68rem;
  font-weight: 700;
  color: var(--muted);
  cursor: pointer;
  transition: all .2s;
  letter-spacing: .04em;
  text-transform: uppercase;
  white-space: nowrap;
}

.tab-btn:hover {
  background: rgba(26,86,219,.07);
  color: var(--blue);
}

.tab-btn.active {
  background: var(--blue);
  color: #fff;
  box-shadow: 0 4px 14px rgba(26,86,219,.35);
}

/* ── Tab panels ── */
.tab-panel {
  display: none;
}

.tab-panel.active {
  display: block;
  animation: fadeIn .25s ease;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(5px); }
  to   { opacity: 1; transform: none; }
}

/* ── Glass card (replaces .insp-panel) ── */
.glass-card {
  background: var(--surface);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 1.5rem;
  box-shadow: 0 8px 32px rgba(0,0,0,.04);
}

/* ── Card section label ── */
.card-label {
  font-family: var(--font-mono);
  font-size: .6rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: .12em;
  font-weight: 700;
  margin-bottom: .9rem;
  display: flex;
  align-items: center;
  gap: .5rem;
}

.card-label::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--border-dark);
}

/* ── Grid layouts ── */
.two-col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.25rem;
}

.two-col-sym {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: .75rem;
  margin-top: .75rem;
}

/* ── Symbol SVG wrapper ── */
.sym-wrap {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1rem;
  background: rgba(255,255,255,.5);
  border: 1px dashed var(--border-dark);
  border-radius: 10px;
  min-height: 80px;
}

/* ── Knowledge blocks ── */
.know-block {
  margin-bottom: 1rem;
}

.know-title {
  font-family: var(--font-mono);
  font-size: .68rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .08em;
  margin-bottom: .45rem;
  color: var(--blue);
}

.know-text {
  font-size: .84rem;
  color: var(--muted);
  line-height: 1.65;
}

.know-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: .38rem;
}

.know-list li {
  font-size: .82rem;
  color: var(--muted);
  display: flex;
  gap: .5rem;
  line-height: 1.5;
}

.know-list li::before {
  content: '→';
  color: var(--blue);
  font-weight: 700;
  flex-shrink: 0;
  font-family: var(--font-mono);
}

/* ── Formula box ── */
.formula-box {
  background: rgba(26,86,219,.06);
  border: 1px solid rgba(26,86,219,.18);
  border-radius: 8px;
  padding: .7rem 1rem;
  font-family: var(--font-mono);
  font-size: .88rem;
  color: var(--blue);
  text-align: center;
  letter-spacing: .04em;
  margin: .5rem 0 .75rem;
}

/* ── Status / info boxes ── */
.status-box {
  border-radius: 10px;
  padding: .7rem .9rem;
  font-family: var(--font-mono);
  font-size: .74rem;
  line-height: 1.55;
}

.status-box.ok   { background: rgba(16,185,129,.08);  border: 1px solid rgba(16,185,129,.25); color: var(--green); }
.status-box.err  { background: rgba(244,63,94,.08);   border: 1px solid rgba(244,63,94,.25);  color: var(--rose);  }
.status-box.warn { background: rgba(245,158,11,.08);  border: 1px solid rgba(245,158,11,.25); color: var(--amber); }
.status-box.info { background: rgba(26,86,219,.07);   border: 1px solid rgba(26,86,219,.18);  color: var(--blue);  }

/* ── Status badge inline ── */
.status-badge {
  display: inline-flex;
  align-items: center;
  gap: .4rem;
  padding: .28rem .75rem;
  border-radius: 999px;
  font-family: var(--font-mono);
  font-size: .7rem;
  font-weight: 700;
}

.s-ok  { background: rgba(16,185,129,.1);  color: var(--green); border: 1px solid rgba(16,185,129,.3); }
.s-err { background: rgba(244,63,94,.1);   color: var(--rose);  border: 1px solid rgba(244,63,94,.3);  }

/* ── Controls stack ── */
.controls-stack {
  display: flex;
  flex-direction: column;
  gap: .6rem;
  margin-top: 1rem;
}

.ctrl-row {
  display: flex;
  align-items: center;
  gap: .6rem;
}

.ctrl-label {
  font-family: var(--font-mono);
  font-size: .7rem;
  color: var(--muted);
  font-weight: 600;
  min-width: 130px;
  flex-shrink: 0;
}

.ctrl-val {
  font-family: var(--font-mono);
  font-size: .82rem;
  color: var(--blue);
  font-weight: 700;
  min-width: 58px;
  text-align: right;
}

.ctrl-unit {
  font-family: var(--font-mono);
  font-size: .72rem;
  color: var(--muted);
  min-width: 28px;
}

input[type="range"] {
  flex: 1;
  accent-color: var(--blue);
  cursor: pointer;
}

.num-input {
  flex: 1;
  padding: .4rem .65rem;
  border: 1px solid var(--border-dark);
  border-radius: 8px;
  font-family: var(--font-mono);
  font-size: .82rem;
  background: rgba(255,255,255,.75);
  color: var(--text);
  outline: none;
  transition: border-color .2s;
}

.num-input:focus {
  border-color: var(--blue);
}

/* ── Band selectors (shared by resistor + inductor + diode) ── */
.band-select {
  padding: .4rem .5rem;
  border: 1px solid var(--border-dark);
  border-radius: 7px;
  font-family: var(--font-body);
  font-size: .78rem;
  background: rgba(255,255,255,.75);
  cursor: pointer;
  outline: none;
  color: var(--text);
  transition: border-color .2s;
}

.band-select:focus {
  border-color: var(--blue);
}

/* ── Reading grid (values display) ── */
.reading-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: .65rem;
  margin-top: .75rem;
}

.reading-card {
  text-align: center;
  padding: .75rem .5rem;
  background: rgba(255,255,255,.6);
  border: 1px solid var(--border);
  border-radius: 10px;
  font-family: var(--font-mono);
}

.reading-val {
  font-size: 1.08rem;
  font-weight: 700;
  color: var(--blue);
  display: block;
}

.reading-lbl {
  font-size: .58rem;
  color: var(--muted);
  margin-top: .2rem;
  line-height: 1.4;
}

/* ── Buttons ── */
.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: .4rem;
  background: var(--blue);
  color: #fff;
  border: none;
  border-radius: 8px;
  padding: .55rem 1.1rem;
  font-family: var(--font-mono);
  font-size: .74rem;
  font-weight: 700;
  cursor: pointer;
  transition: all .2s;
  letter-spacing: .02em;
}

.btn-primary:hover {
  background: #1244b5;
  transform: translateY(-1px);
  box-shadow: 0 4px 14px rgba(26,86,219,.3);
}

.full-w {
  width: 100%;
  margin-top: .75rem;
}

.btn-toggle {
  display: inline-flex;
  align-items: center;
  gap: .4rem;
  background: rgba(255,255,255,.7);
  color: var(--muted);
  border: 1px solid var(--border-dark);
  border-radius: 8px;
  padding: .5rem 1rem;
  font-family: var(--font-mono);
  font-size: .74rem;
  font-weight: 700;
  cursor: pointer;
  transition: all .2s;
}

.btn-toggle.on {
  background: var(--green);
  color: #fff;
  border-color: var(--green);
  box-shadow: 0 4px 12px rgba(16,185,129,.3);
}

/* ── Toggle switch ── */
.toggle-wrap {
  display: flex;
  align-items: center;
  gap: .75rem;
  cursor: pointer;
  user-select: none;
  margin: .65rem 0;
}

.toggle-track {
  width: 44px;
  height: 24px;
  background: rgba(0,0,0,.1);
  border-radius: 12px;
  position: relative;
  transition: background .3s;
  flex-shrink: 0;
}

.toggle-track.on      { background: var(--green); }
.toggle-track.err-on  { background: var(--rose);  }

.toggle-thumb {
  position: absolute;
  top: 3px;
  left: 3px;
  width: 18px;
  height: 18px;
  background: #fff;
  border-radius: 50%;
  transition: left .3s;
  box-shadow: 0 2px 4px rgba(0,0,0,.25);
}

.toggle-track.on .toggle-thumb,
.toggle-track.err-on .toggle-thumb {
  left: calc(100% - 21px);
}

.toggle-label {
  font-family: var(--font-mono);
  font-size: .76rem;
  font-weight: 600;
  color: var(--muted);
}

/* ═══════════════ RESISTOR ═══════════════ */
.res-svg-area {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 2rem 1rem;
  background: linear-gradient(135deg,rgba(255,255,255,.65),rgba(255,255,255,.2));
  border-radius: 12px;
  border: 1px dashed var(--border-dark);
}

.band-selectors {
  display: flex;
  gap: .6rem;
  margin-top: 1.25rem;
  flex-wrap: wrap;
  justify-content: space-between;
}

.band-slot {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: .35rem;
  flex: 1;
  min-width: 72px;
}

.band-slot-lbl {
  font-family: var(--font-mono);
  font-size: .58rem;
  color: var(--muted);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .05em;
  text-align: center;
}

.band-indicator {
  width: 28px;
  height: 28px;
  border-radius: 6px;
  border: 2px solid rgba(0,0,0,.15);
  box-shadow: 0 2px 6px rgba(0,0,0,.15);
  transition: transform .2s;
}

.band-slot .band-select {
  width: 100%;
  font-size: .68rem;
}

.res-display {
  text-align: center;
  padding: 1.1rem;
  background: rgba(26,86,219,.05);
  border: 1px solid rgba(26,86,219,.18);
  border-radius: 12px;
  margin-top: 1.1rem;
}

.res-value {
  font-family: var(--font-mono);
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--blue);
  display: block;
}

.res-range {
  font-family: var(--font-mono);
  font-size: .72rem;
  color: var(--muted);
  display: block;
  margin-top: .25rem;
}

/* Color reference table */
.color-tbl {
  width: 100%;
  border-collapse: collapse;
  font-family: var(--font-mono);
  font-size: .7rem;
}

.color-tbl th {
  background: rgba(26,86,219,.07);
  padding: .45rem .65rem;
  text-align: left;
  font-size: .58rem;
  text-transform: uppercase;
  letter-spacing: .08em;
  color: var(--muted);
  border-bottom: 1px solid var(--border-dark);
}

.color-tbl td {
  padding: .38rem .65rem;
  border-bottom: 1px solid rgba(0,0,0,.04);
  vertical-align: middle;
}

.color-tbl tr:last-child td { border-bottom: none; }
.color-tbl tr:hover td { background: rgba(26,86,219,.02); }

.cdot {
  display: inline-block;
  width: 14px;
  height: 14px;
  border-radius: 3px;
  vertical-align: middle;
  margin-right: .45rem;
  border: 1px solid rgba(0,0,0,.12);
  flex-shrink: 0;
}

/* ═══════════════ CAPACITOR ═══════════════ */
.cap-svg-wrap {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1.5rem;
  background: rgba(255,255,255,.5);
  border: 1px dashed var(--border-dark);
  border-radius: 12px;
}

/* ═══════════════ INDUCTOR ═══════════════ */
.mag-field-wrap {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1.25rem;
  background: rgba(255,255,255,.5);
  border: 1px dashed var(--border-dark);
  border-radius: 12px;
}

/* Animated magnetic rings */
@keyframes magPulse  { 0%,100%{opacity:.15} 50%{opacity:.5}  }
@keyframes magPulse2 { 0%,100%{opacity:.1}  50%{opacity:.35} }
@keyframes magPulse3 { 0%,100%{opacity:.06} 50%{opacity:.2}  }

.mag-ring  { animation: magPulse  2s ease-in-out infinite;      }
.mag-ring2 { animation: magPulse2 2s ease-in-out infinite .4s;  }
.mag-ring3 { animation: magPulse3 2s ease-in-out infinite .8s;  }

/* ═══════════════ DIODE ═══════════════ */
.diode-visual {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1.5rem 1rem;
  background: rgba(255,255,255,.5);
  border: 1px dashed var(--border-dark);
  border-radius: 12px;
  overflow: hidden;
}

.flow-track {
  position: absolute;
  left: 0; right: 0;
  top: 50%;
  height: 4px;
  margin-top: -2px;
  pointer-events: none;
}

@keyframes flowR { 0%{left:-30px;opacity:1} 80%{opacity:1} 100%{left:calc(100% + 30px);opacity:0} }

.particle {
  position: absolute;
  width: 26px;
  height: 4px;
  border-radius: 2px;
  background: var(--green);
  box-shadow: 0 0 6px var(--green);
  animation: flowR 1.2s linear infinite;
  display: none;
}

.particle:nth-child(2) { animation-delay: .4s; }
.particle:nth-child(3) { animation-delay: .8s; }
.flow-active .particle { display: block; }

.bias-btns {
  display: flex;
  gap: .6rem;
  margin-top: .75rem;
}

.bias-btn {
  flex: 1;
  padding: .5rem;
  border: 1px solid var(--border-dark);
  border-radius: 8px;
  font-family: var(--font-mono);
  font-size: .72rem;
  font-weight: 700;
  cursor: pointer;
  transition: all .2s;
  background: rgba(255,255,255,.7);
  color: var(--muted);
  text-align: center;
}

.bias-btn.active-fwd {
  background: var(--green);
  color: #fff;
  border-color: var(--green);
  box-shadow: 0 3px 10px rgba(16,185,129,.3);
}

.bias-btn.active-rev {
  background: var(--rose);
  color: #fff;
  border-color: var(--rose);
  box-shadow: 0 3px 10px rgba(244,63,94,.3);
}

/* ═══════════════ LED ═══════════════ */
.led-stage {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  height: 200px;
  background: rgba(10,10,20,.9);
  border-radius: 14px;
  overflow: hidden;
  border: 1px solid #1e2233;
}

.led-glow-bg {
  position: absolute;
  inset: 0;
  border-radius: 14px;
  opacity: 0;
  transition: opacity .5s;
}

.led-power-indicator {
  position: absolute;
  top: 12px;
  right: 14px;
  z-index: 3;
  font-family: var(--font-mono);
  font-size: .65rem;
  font-weight: 700;
  opacity: 0;
  transition: opacity .4s;
}

.led-palette {
  display: flex;
  gap: .6rem;
  flex-wrap: wrap;
  margin-top: 1rem;
  justify-content: center;
}

.led-swatch {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  cursor: pointer;
  border: 3px solid transparent;
  transition: all .2s;
  outline: none;
}

.led-swatch:hover    { transform: scale(1.18); }
.led-swatch.active   { border-color: #fff; box-shadow: 0 0 0 3px rgba(0,0,0,.2); }

.led-controls {
  display: flex;
  align-items: center;
  gap: .75rem;
  justify-content: center;
  margin-top: 1rem;
}

/* LED material table */
.led-dot {
  display: inline-block;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  vertical-align: middle;
  margin-right: .4rem;
  border: 1.5px solid rgba(0,0,0,.15);
}

/* ═══════════════ MULTIMETER ═══════════════ */
.meter-layout {
  display: flex;
  gap: 1.5rem;
  align-items: flex-start;
  flex-wrap: wrap;
}

.meter-svg-wrap { flex-shrink: 0; }

.meter-right {
  flex: 1;
  min-width: 260px;
}

.meter-display {
  background: #0d1a0d;
  border-radius: 10px;
  padding: .9rem 1.25rem;
  font-family: var(--font-mono);
  margin-bottom: 1rem;
  border: 2px solid #1a2e1a;
  box-shadow: inset 0 2px 10px rgba(0,0,0,.6);
}

.meter-val {
  font-size: 1.9rem;
  font-weight: 700;
  color: #39ff14;
  text-shadow: 0 0 12px rgba(57,255,20,.6);
  letter-spacing: .1em;
  display: block;
  text-align: right;
}

.meter-unit {
  font-size: .65rem;
  color: #39ff14;
  opacity: .65;
  text-align: right;
  display: block;
  margin-top: .2rem;
  letter-spacing: .06em;
}

.meter-mode-lbl {
  font-size: .58rem;
  color: #39ff14;
  opacity: .45;
  display: block;
  letter-spacing: .12em;
  margin-bottom: .2rem;
}

.connect-select {
  width: 100%;
  padding: .45rem .7rem;
  border: 1px solid var(--border-dark);
  border-radius: 8px;
  font-family: var(--font-mono);
  font-size: .72rem;
  background: rgba(255,255,255,.75);
  color: var(--text);
  outline: none;
  margin-bottom: .45rem;
  cursor: pointer;
  transition: border-color .2s;
}

.connect-select:focus { border-color: var(--blue); }

.probe-jacks {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: .5rem;
  margin-bottom: .6rem;
}

.probe-jack {
  border-radius: 8px;
  padding: .45rem .5rem;
  font-family: var(--font-mono);
  font-size: .65rem;
  font-weight: 700;
  background: rgba(255,255,255,.65);
  border: 1px solid var(--border-dark);
  text-align: center;
  cursor: pointer;
  transition: all .2s;
}

.probe-jack:hover   { background: #fff; }
.probe-jack.selected { box-shadow: 0 0 0 2px var(--blue); }

.jack-com  { border-left: 4px solid #1a1a1a; }
.jack-vohm { border-left: 4px solid var(--rose); }
.jack-amp  { border-left: 4px solid var(--amber); }

.dial-grid {
  display: grid;
  grid-template-columns: repeat(3,1fr);
  gap: .35rem;
}

.dial-btn {
  padding: .42rem .35rem;
  border: 1px solid var(--border-dark);
  background: rgba(255,255,255,.6);
  border-radius: 7px;
  font-family: var(--font-mono);
  font-size: .6rem;
  color: var(--muted);
  cursor: pointer;
  transition: all .2s;
  text-align: center;
  line-height: 1.3;
}

.dial-btn:hover { background: rgba(26,86,219,.07); color: var(--blue); }
.dial-btn.active { background: var(--blue); color: #fff; border-color: var(--blue); box-shadow: 0 2px 8px rgba(26,86,219,.3); }
.dial-btn.d-off  { color: var(--rose); }
.dial-btn.d-off.active { background: var(--rose); border-color: var(--rose); box-shadow: 0 2px 8px rgba(244,63,94,.3); }

/* ═══════════════ BREADBOARD ═══════════════ */
.bb-toolbar {
  display: flex;
  gap: .4rem;
  flex-wrap: wrap;
  margin-bottom: .9rem;
}

.bb-tool {
  display: flex;
  align-items: center;
  gap: .35rem;
  padding: .38rem .72rem;
  border: 1px solid var(--border-dark);
  border-radius: 8px;
  background: rgba(255,255,255,.65);
  font-family: var(--font-mono);
  font-size: .66rem;
  cursor: pointer;
  transition: all .2s;
  color: var(--muted);
  white-space: nowrap;
  font-weight: 600;
}

.bb-tool:hover  { background: #fff; color: var(--text); }
.bb-tool.active { background: var(--blue); color: #fff; border-color: var(--blue); }

.bb-tool-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  border: 1.5px solid rgba(0,0,0,.2);
  flex-shrink: 0;
}

/* Breadboard surface */
.breadboard {
  background: linear-gradient(180deg,#1a5c1a,#164e16);
  border-radius: 14px;
  padding: 1rem .9rem;
  box-shadow: inset 0 4px 12px rgba(0,0,0,.35), 0 6px 20px rgba(0,0,0,.12);
  overflow-x: auto;
}

.bb-numbers {
  display: flex;
  gap: 3px;
  margin-left: 26px;
  margin-bottom: 3px;
}

.bb-num {
  width: 14px;
  font-family: var(--font-mono);
  font-size: .42rem;
  color: rgba(255,255,255,.38);
  text-align: center;
  flex-shrink: 0;
}

.bb-row {
  display: flex;
  gap: 3px;
  align-items: center;
  margin-bottom: 2px;
}

.bb-row-lbl {
  font-family: var(--font-mono);
  font-size: .55rem;
  color: rgba(255,255,255,.45);
  width: 20px;
  text-align: center;
  flex-shrink: 0;
  font-weight: 700;
}

/* Holes */
.bb-hole {
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: #0c2a0c;
  border: 1px solid rgba(255,255,255,.1);
  cursor: pointer;
  transition: all .15s;
  flex-shrink: 0;
}

.bb-hole:hover { background: #1a4a1a; transform: scale(1.15); z-index: 1; position: relative; }

.bb-hole.h-red { background: #dc2626; box-shadow: 0 0 7px #dc2626; border-color: #ef4444; }
.bb-hole.h-blk { background: #1a1a1a; box-shadow: 0 0 5px #000;    border-color: #333;    }
.bb-hole.h-yel { background: #d97706; box-shadow: 0 0 7px #d97706; border-color: #f59e0b; }
.bb-hole.h-grn { background: #16a34a; box-shadow: 0 0 7px #16a34a; border-color: #22c55e; }
.bb-hole.h-led { background: #a855f7; box-shadow: 0 0 9px #a855f7; border-color: #c084fc; }
.bb-hole.h-res { background: #b45309; box-shadow: 0 0 7px #b45309; border-color: #d97706; }

.bb-rail-bar   { height: 6px; border-radius: 3px; margin: 3px 0; }
.bb-rail-plus  { background: linear-gradient(90deg,#dc2626,#ef4444); opacity: .7; }
.bb-rail-minus { background: linear-gradient(90deg,#1d4ed8,#3b82f6); opacity: .7; }

.bb-gap     { height: 10px; }
.bb-divider { display: flex; gap: 3px; margin-bottom: 2px; margin-top: 2px; }
.bb-div-seg { flex: 1; height: 2px; background: rgba(255,255,255,.15); border-radius: 1px; }

/* ── Responsive ── */
@media (max-width: 900px) {
  .two-col,
  .two-col-sym,
  .meter-layout { grid-template-columns: 1fr; }

  .band-selectors { gap: .4rem; }
  .band-slot      { min-width: 60px; }
  .page-header h1 { font-size: 1.7rem; }
  .tab-btn        { font-size: .6rem; padding: .38rem .65rem; }
}

@media (max-width: 600px) {
  .page { padding-left: 1rem; padding-right: 1rem; }
  .dial-grid { grid-template-columns: repeat(2,1fr); }
  .probe-jacks { grid-template-columns: 1fr 1fr; }
  .reading-grid { grid-template-columns: 1fr; }
}