:root {
  --bg: #0f1419;
  --surface: #1a2332;
  --surface2: #243044;
  --border: #334155;
  --text: #e2e8f0;
  --muted: #94a3b8;
  --accent: #38bdf8;
  --led-on: #22c55e;
  --led-off: #ef4444;
  --led-glow-on: rgba(34, 197, 94, 0.55);
  --led-glow-off: rgba(239, 68, 68, 0.45);
  --output-hover: #fbbf24;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Segoe UI", system-ui, -apple-system, sans-serif;
  background: radial-gradient(ellipse at top, #1e293b 0%, var(--bg) 55%);
  color: var(--text);
  min-height: 100vh;
}

header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 1rem 1.5rem;
  border-bottom: 1px solid var(--border);
  background: rgba(15, 20, 25, 0.85);
  backdrop-filter: blur(8px);
  position: sticky;
  top: 0;
  z-index: 10;
}

header h1 {
  margin: 0;
  font-size: 1.35rem;
  font-weight: 600;
  letter-spacing: 0.02em;
}

header h1 span {
  color: var(--accent);
  font-weight: 400;
}

.status {
  font-size: 0.9rem;
  color: var(--muted);
}

.status.connected {
  color: var(--led-on);
}

.toolbar {
  display: flex;
  gap: 0.75rem;
  align-items: center;
}

button {
  border: 1px solid var(--border);
  background: var(--surface2);
  color: var(--text);
  padding: 0.55rem 1rem;
  border-radius: 8px;
  cursor: pointer;
  font-size: 0.95rem;
  transition: background 0.15s, border-color 0.15s;
}

button:hover:not(:disabled) {
  background: #2f3f56;
  border-color: var(--accent);
}

button:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}

button.primary {
  background: #0369a1;
  border-color: #0284c7;
}

button.primary:hover:not(:disabled) {
  background: #0284c7;
}

main {
  max-width: 1400px;
  margin: 0 auto;
  padding: 1.25rem;
}

.layout {
  display: grid;
  grid-template-columns: minmax(300px, 440px) 1fr;
  gap: 1.5rem;
  align-items: start;
}

.left-column {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  min-width: 0;
}

@media (max-width: 960px) {
  .layout {
    grid-template-columns: 1fr;
  }
}

.board-panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 0.3rem;
  text-align: center;
}

.board-panel img {
  width: 100%;
  max-width: 480px;
}

.board-panel p {
  margin: 0.75rem 0 0;
  color: var(--muted);
  font-size: 0.85rem;
  line-height: 1.45;
}

/* ── Sensors (I2C) ── */

.sensors-panel {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 0.55rem;
  padding: 0.5rem 0.65rem 0.65rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  overflow: hidden;
}

.sensors-panel::before {
  content: "";
  position: absolute;
  inset: 0;
  background: url("../images/sensors.png") right top / auto 72px no-repeat;
  opacity: 0.1;
  pointer-events: none;
}

.sensors-header {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-shrink: 0;
}

.sensors-icon {
  flex-shrink: 0;
  border-radius: 4px;
}

.sensors-title {
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  flex-shrink: 0;
}

.btn-i2c-scan {
  margin-left: auto;
  padding: 0.3rem 0.55rem;
  font-size: 0.72rem;
  font-family: ui-monospace, monospace;
  min-width: 5.5rem;
  max-width: 100%;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  border-radius: 6px;
  flex-shrink: 0;
}

.sensor-buttons {
  position: relative;
  z-index: 1;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  min-height: 0;
}

.sensor-buttons-empty {
  margin: 0;
  width: 100%;
  font-size: 0.72rem;
  color: var(--muted);
  text-align: center;
  padding: 0.35rem 0;
}

.sensor-chip {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.25rem;
  padding: 0.45rem 0.55rem 0.4rem;
  min-width: 5.5rem;
  max-width: 6.5rem;
  font-size: 0.68rem;
  border-radius: 10px;
  background: rgba(15, 20, 25, 0.82);
  border: 1px solid var(--border);
  text-align: center;
  line-height: 1.2;
}

.sensor-chip-icon {
  width: 52px;
  height: 52px;
  border-radius: 8px;
  object-fit: cover;
  background: rgba(0, 0, 0, 0.25);
}

.sensor-chip-name {
  font-weight: 600;
  color: var(--text);
  font-size: 0.7rem;
  word-break: break-word;
}

.sensor-chip-addr {
  font-family: ui-monospace, monospace;
  font-size: 0.62rem;
  color: var(--muted);
}

.sensor-chip:hover:not(:disabled) {
  border-color: var(--accent);
  background: rgba(56, 189, 248, 0.12);
  transform: translateY(-1px);
}

.sensor-chip:active:not(:disabled) {
  transform: translateY(0);
}

/* ── Sensor dialog ── */

.sensor-overlay {
  position: fixed;
  inset: 0;
  z-index: 100;
  background: rgba(0, 0, 0, 0.62);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem;
}

.sensor-dialog {
  width: min(1120px, 96vw);
  height: min(88vh, 860px);
  min-height: 520px;
  display: flex;
  flex-direction: column;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  overflow: hidden;
  box-shadow: 0 24px 64px rgba(0, 0, 0, 0.55);
}

.sensor-dialog-header {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  padding: 1rem 1.25rem;
  background: var(--surface2);
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
}

.sensor-dialog-icon {
  width: 44px;
  height: 44px;
  border-radius: 8px;
  object-fit: cover;
}

.sensor-dialog-header h2 {
  margin: 0;
  font-size: 1.15rem;
}

.sensor-dialog-addr {
  margin: 0.15rem 0 0;
  font-size: 0.75rem;
  color: var(--muted);
  font-family: ui-monospace, monospace;
}

.sensor-close {
  margin-left: auto;
  width: 32px;
  height: 32px;
  padding: 0;
  font-size: 1.4rem;
  line-height: 1;
  border-radius: 8px;
}

.sensor-config {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 0.75rem;
  padding: 0.65rem 1rem;
  border-bottom: 1px solid rgba(51, 65, 85, 0.5);
  background: rgba(0, 0, 0, 0.15);
}

.sensor-config-item {
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
  font-size: 0.68rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.sensor-config-item select {
  padding: 0.3rem 0.45rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--bg);
  color: var(--text);
  font-size: 0.78rem;
  min-width: 7rem;
}

.sensor-body {
  flex: 1;
  min-height: 0;
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
  padding: 0.65rem 1.25rem 1rem;
  overflow: hidden;
}

.sensor-gauges-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.85rem;
  justify-content: center;
  align-items: flex-start;
  flex-shrink: 0;
}

.sensor-gauges-row .analog-gauge {
  flex: 0 1 200px;
  min-width: 160px;
  max-width: 240px;
}

.sensor-gauges-row .gauge-face {
  max-width: 200px;
}

.sensor-logger-panel {
  flex: 1;
  min-height: 0;
  display: flex;
  flex-direction: column;
  gap: 0.45rem;
}

.sensor-logger-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem;
  flex-shrink: 0;
}

.sensor-logger-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.35rem;
  margin-left: auto;
}

.sensor-timing-fields {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem 0.75rem;
  margin-right: 0.35rem;
}

.sensor-num-field {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  font-size: 0.68rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.sensor-num-field input {
  width: 3.5rem;
  padding: 0.28rem 0.4rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--bg);
  color: var(--text);
  font-family: ui-monospace, monospace;
  font-size: 0.78rem;
  text-transform: none;
  letter-spacing: 0;
}

.sensor-num-field input:focus {
  outline: none;
  border-color: var(--accent);
}

.sensor-num-unit {
  text-transform: none;
  font-family: ui-monospace, monospace;
  font-size: 0.72rem;
}

.sensor-logger-pause,
.sensor-logger-clear,
.sensor-logger-reset {
  padding: 0.3rem 0.6rem;
  font-size: 0.72rem;
}

.sensor-trace-toggles {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}

.sensor-trace-toggle {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.28rem 0.55rem;
  font-size: 0.72rem;
  border-radius: 999px;
  background: rgba(15, 20, 25, 0.6);
  border: 1px solid var(--border);
  opacity: 0.45;
  transition: opacity 0.15s, border-color 0.15s, background 0.15s;
}

.sensor-trace-toggle.active {
  opacity: 1;
  border-color: var(--accent);
  background: rgba(56, 189, 248, 0.1);
}

.trace-swatch {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  flex-shrink: 0;
}

.sensor-chart-wrap {
  position: relative;
  flex: 1;
  min-height: 180px;
  width: 100%;
  border-radius: 10px;
  overflow: hidden;
  border: 1px solid var(--border);
  background: #0b1018;
}

.sensor-chart {
  position: absolute;
  inset: 0;
  width: 100% !important;
  height: 100% !important;
  touch-action: none;
}

.sensor-dialog-footer {
  padding: 0.6rem 1.25rem;
  border-top: 1px solid var(--border);
  font-size: 0.75rem;
  color: var(--muted);
  flex-shrink: 0;
}

/* ── Analog gauge ── */

.analog-gauge {
  text-align: center;
  padding: 0.5rem 0.35rem 0.25rem;
  background: linear-gradient(180deg, rgba(30, 41, 59, 0.45) 0%, rgba(15, 20, 25, 0.2) 100%);
  border: 1px solid rgba(51, 65, 85, 0.6);
  border-radius: 12px;
}

.gauge-face {
  max-width: 260px;
  margin: 0 auto;
  filter: drop-shadow(0 4px 12px rgba(0, 0, 0, 0.35));
}

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

.gauge-track {
  fill: none;
  stroke-width: 12;
  stroke-linecap: round;
}

.gauge-value-arc {
  fill: none;
  stroke-width: 8;
  stroke-linecap: round;
  transition: d 0.35s ease-out;
}

.gauge-tick-major {
  stroke: #64748b;
  stroke-width: 1.5;
}

.gauge-tick-minor {
  stroke: #475569;
  stroke-width: 1;
}

.gauge-tick-label {
  fill: #94a3b8;
  font-size: 9px;
  font-family: ui-monospace, monospace;
}

.gauge-hub-outer {
  fill: #1e293b;
  stroke: #475569;
  stroke-width: 1;
}

.gauge-hub {
  fill: #0f172a;
  stroke: var(--accent);
  stroke-width: 1.5;
}

.gauge-needle {
  stroke: #f8fafc;
  stroke-width: 2.8;
  stroke-linecap: round;
  filter: drop-shadow(0 0 4px rgba(56, 189, 248, 0.6));
  transition: x2 0.35s cubic-bezier(0.34, 1.2, 0.64, 1),
              y2 0.35s cubic-bezier(0.34, 1.2, 0.64, 1);
}

.gauge-readout {
  margin-top: 0.15rem;
}

.gauge-label {
  display: block;
  font-size: 0.7rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.gauge-value-row {
  display: flex;
  align-items: baseline;
  justify-content: center;
  gap: 0.25rem;
}

.gauge-value {
  font-family: ui-monospace, monospace;
  font-size: 1.45rem;
  font-weight: 700;
  color: var(--accent);
  line-height: 1.2;
  text-shadow: 0 0 20px rgba(56, 189, 248, 0.25);
}

.gauge-unit {
  font-size: 0.78rem;
  color: var(--muted);
}

.gauge-range {
  display: block;
  margin-top: 0.2rem;
  font-size: 0.62rem;
  color: #64748b;
  font-family: ui-monospace, monospace;
}

.ports-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
}

@media (max-width: 700px) {
  .ports-grid {
    grid-template-columns: 1fr;
  }
}

.port-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 14px;
  overflow: hidden;
}

.port-header {
  padding: 0.65rem 0.9rem;
  background: var(--surface2);
  border-bottom: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  align-items: baseline;
}

.port-header h2 {
  margin: 0;
  font-size: 1.05rem;
  color: var(--accent);
}

.port-regs {
  font-family: ui-monospace, "Cascadia Code", monospace;
  font-size: 0.72rem;
  color: var(--muted);
  text-align: right;
  line-height: 1.35;
}

.pin-list {
  padding: 0.5rem 0.75rem 0.75rem;
}

.pin-row {
  display: grid;
  grid-template-columns: 44px 1fr 88px;
  align-items: center;
  gap: 0.5rem;
  padding: 0.35rem 0;
  border-bottom: 1px solid rgba(51, 65, 85, 0.45);
}

.pin-row:last-child {
  border-bottom: none;
}

.pin-label {
  font-family: ui-monospace, monospace;
  font-size: 0.82rem;
}

.pin-label small {
  display: block;
  color: var(--muted);
  font-size: 0.68rem;
}

.pin-row--tristate .pin-label.pin-label--adc {
  cursor: pointer;
}

.pin-row--tristate .pin-label.pin-label--adc:hover .pin-name {
  color: #38bdf8;
}

.led {
  width: 36px;
  height: 36px;
  border-radius: 8px;
  border: 2px solid rgba(255, 255, 255, 0.12);
  transition: background 0.12s, box-shadow 0.12s, transform 0.1s;
  justify-self: center;
}

.led.high {
  background: var(--led-on);
  box-shadow: 0 0 14px var(--led-glow-on);
}

.led.low {
  background: var(--led-off);
  box-shadow: 0 0 10px var(--led-glow-off);
}

.led.output {
  cursor: pointer;
}

.led.output:hover {
  outline: 2px solid var(--output-hover);
  transform: scale(1.06);
}

.led.output:active {
  transform: scale(0.96);
}

.led.input {
  cursor: default;
}

.io-switch {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 0.35rem;
  font-size: 0.72rem;
  color: var(--muted);
  user-select: none;
}

.io-switch input {
  appearance: none;
  width: 42px;
  height: 22px;
  background: #475569;
  border-radius: 999px;
  position: relative;
  cursor: pointer;
  transition: background 0.15s;
  flex-shrink: 0;
}

.io-switch input::after {
  content: "";
  position: absolute;
  top: 2px;
  left: 2px;
  width: 18px;
  height: 18px;
  background: white;
  border-radius: 50%;
  transition: transform 0.15s;
}

.io-switch input:checked {
  background: #0ea5e9;
}

.io-switch input:checked::after {
  transform: translateX(20px);
}

.io-switch input:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.pin-row--tristate {
  grid-template-columns: 44px 1fr 132px;
}

.pin-adc-val {
  font-family: ui-monospace, monospace;
  font-size: 0.78rem;
  color: #38bdf8;
  font-weight: 600;
}

.io-tristate {
  display: flex;
  border-radius: 999px;
  overflow: hidden;
  border: 1px solid rgba(148, 163, 184, 0.35);
  background: #334155;
}

.io-tristate .io-pos {
  flex: 1;
  min-width: 0;
  padding: 0.28rem 0.15rem;
  border: none;
  background: transparent;
  color: var(--muted);
  font-size: 0.62rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  cursor: pointer;
  transition: background 0.12s, color 0.12s;
}

.io-tristate .io-pos:not(:last-child) {
  border-right: 1px solid rgba(148, 163, 184, 0.25);
}

.io-tristate .io-pos.active {
  color: #0f172a;
}

.io-tristate[data-mode="input"] .io-pos[data-mode="input"] {
  background: #94a3b8;
}

.io-tristate[data-mode="adc"] .io-pos[data-mode="adc"] {
  background: #a78bfa;
}

.io-tristate[data-mode="output"] .io-pos[data-mode="output"] {
  background: #0ea5e9;
}

.io-tristate .io-pos:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.hint {
  margin-top: 1rem;
  padding: 0.85rem 1rem;
  background: rgba(56, 189, 248, 0.08);
  border: 1px solid rgba(56, 189, 248, 0.25);
  border-radius: 10px;
  color: var(--muted);
  font-size: 0.85rem;
  line-height: 1.5;
}

.hint strong {
  color: var(--accent);
}

/* ── Register terminal ── */

.reg-terminal {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 14px;
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.bit-converter {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.65rem 0.85rem;
  padding: 0.65rem 0.85rem;
  background: var(--surface2);
  border-bottom: 1px solid var(--border);
}

.converter-label {
  font-size: 0.78rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--accent);
  width: 100%;
  margin-bottom: -0.25rem;
}

.bit-leds {
  display: flex;
  gap: 4px;
  flex: 1;
  min-width: 200px;
}

.bit-led {
  flex: 1;
  min-width: 28px;
  height: 36px;
  border-radius: 6px;
  border: 2px solid rgba(255, 255, 255, 0.1);
  cursor: pointer;
  padding: 0;
  transition: background 0.1s, transform 0.1s;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: ui-monospace, monospace;
  font-size: 0.8rem;
  font-weight: 700;
  color: rgba(255, 255, 255, 0.9);
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.45);
}

.bit-led:hover {
  transform: scale(1.05);
  outline: 1px solid var(--accent);
}

.bit-led.high {
  background: var(--led-on);
  box-shadow: 0 0 10px var(--led-glow-on);
}

.bit-led.low {
  background: var(--led-off);
  box-shadow: 0 0 8px var(--led-glow-off);
}

.conv-field {
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
  font-size: 0.68rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.conv-field input {
  width: 4.5rem;
  padding: 0.35rem 0.45rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--bg);
  color: var(--text);
  font-family: ui-monospace, monospace;
  font-size: 0.9rem;
}

.conv-field input:focus {
  outline: none;
  border-color: var(--accent);
}

.reg-row {
  display: grid;
  grid-template-columns: 1fr 4.5rem 36px 36px 22px;
  gap: 0.45rem;
  align-items: center;
  padding: 0.55rem 0.75rem;
  border-bottom: 1px solid rgba(51, 65, 85, 0.5);
}

.reg-warn {
  color: #fbbf24;
  font-size: 1rem;
  line-height: 1;
  cursor: help;
  text-align: center;
  justify-self: end;
}

.reg-name,
.reg-value {
  padding: 0.35rem 0.45rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--bg);
  color: var(--text);
  font-family: ui-monospace, monospace;
  font-size: 0.82rem;
  width: 100%;
  min-width: 0;
}

.reg-name:focus,
.reg-value:focus {
  outline: none;
  border-color: var(--accent);
}

.reg-btn {
  width: 32px;
  height: 32px;
  padding: 0;
  border-radius: 6px;
  font-size: 1.1rem;
  line-height: 1;
  display: flex;
  align-items: center;
  justify-content: center;
}

.reg-btn.read {
  color: var(--led-on);
  border-color: rgba(34, 197, 94, 0.35);
}

.reg-btn.write {
  color: #f97316;
  border-color: rgba(249, 115, 22, 0.35);
}

.reg-history {
  width: 100%;
  min-height: 110px;
  max-height: 160px;
  resize: vertical;
  padding: 0.55rem 0.75rem;
  border: none;
  border-top: 1px solid var(--border);
  background: rgba(0, 0, 0, 0.22);
  color: var(--text);
  font-family: ui-monospace, monospace;
  font-size: 0.75rem;
  line-height: 1.45;
}

.reg-history:focus {
  outline: none;
}