* { margin: 0; padding: 0; box-sizing: border-box; }
body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  background: #0d0d1a;
  color: #fff;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Header */
.header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 18px 40px;
  background: rgba(0,0,0,0.4);
  border-bottom: 1px solid rgba(255,255,255,0.06);
  position: sticky;
  top: 0;
  z-index: 10;
}
.logo {
  font-size: 20px;
  font-weight: 800;
  letter-spacing: -0.5px;
  color: #fff;
}
.logo span { color: #00d4aa; }
.status { display: flex; align-items: center; gap: 8px; font-size: 13px; color: #666; }
.dot {
  width: 8px; height: 8px; border-radius: 50%;
  background: #00d4aa;
  box-shadow: 0 0 8px #00d4aa;
}
.dot.off { background: #ff3366; box-shadow: 0 0 8px #ff3366; }

/* Main */
.main {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 40px 20px 60px;
}

/* Gauge */
.gauge-wrap {
  position: relative;
  width: 320px;
  height: 180px;
  margin-bottom: 40px;
}
.gauge { width: 100%; height: 100%; }
.gauge-readout {
  position: absolute;
  bottom: 5px;
  left: 50%;
  transform: translateX(-50%);
  text-align: center;
}
.speed-num {
  font-size: 56px;
  font-weight: 800;
  line-height: 1;
  color: #fff;
  letter-spacing: -2px;
}
.speed-u { font-size: 14px; color: #555; text-transform: uppercase; letter-spacing: 2px; }
.phase { font-size: 12px; color: #444; margin-top: 4px; text-transform: uppercase; letter-spacing: 3px; }

/* Cards */
.cards {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  width: 100%;
  max-width: 760px;
  margin-bottom: 40px;
}
.card {
  background: #141425;
  border: 1px solid rgba(255,255,255,0.06);
  border-radius: 12px;
  padding: 20px 12px;
  text-align: center;
  transition: all 0.3s;
}
.card.active {
  border-color: #00d4aa;
  background: rgba(0,212,170,0.06);
  box-shadow: 0 0 30px rgba(0,212,170,0.1);
}
.c-icon { font-size: 22px; margin-bottom: 6px; color: #00d4aa; }
.c-label { font-size: 10px; color: #555; letter-spacing: 2px; margin-bottom: 8px; font-weight: 600; }
.c-val { font-size: 28px; font-weight: 700; color: #fff; }
.c-unit { font-size: 12px; color: #444; margin-top: 2px; }
.c-sub { font-size: 10px; color: #333; margin-top: 8px; min-height: 14px; }

/* GO Button */
.go-btn {
  width: 160px; height: 160px;
  border-radius: 50%;
  background: linear-gradient(135deg, #00d4aa, #00a88a);
  border: none;
  cursor: pointer;
  color: #0d0d1a;
  font-size: 28px;
  font-weight: 800;
  letter-spacing: 2px;
  box-shadow: 0 0 50px rgba(0,212,170,0.3), inset 0 2px 20px rgba(255,255,255,0.2);
  transition: all 0.25s;
  margin-bottom: 40px;
}
.go-btn:hover:not(:disabled) { transform: scale(1.06); box-shadow: 0 0 70px rgba(0,212,170,0.5); }
.go-btn:active:not(:disabled) { transform: scale(0.97); }
.go-btn:disabled { background: #222; color: #555; box-shadow: none; cursor: not-allowed; }

/* Info bar */
.info {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 13px;
  color: #555;
  padding: 12px 24px;
  background: #141425;
  border-radius: 8px;
  border: 1px solid rgba(255,255,255,0.05);
  margin-bottom: 30px;
}
.info-v { color: #aaa; font-weight: 600; }
.info-sep { color: #333; }

/* History */
.history { width: 100%; max-width: 640px; }
.hist-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 12px;
  font-size: 12px;
  color: #444;
  text-transform: uppercase;
  letter-spacing: 2px;
}
.clr-btn {
  background: none; border: none; color: #ff3366;
  cursor: pointer; font-size: 12px; padding: 4px 10px; border-radius: 4px;
}
.clr-btn:hover { background: rgba(255,51,102,0.1); }
.hist-list { display: flex; flex-direction: column; gap: 6px; }
.hitem {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px 14px;
  background: #141425;
  border-radius: 8px;
  border: 1px solid rgba(255,255,255,0.04);
  font-size: 13px;
}
.ht { color: #444; }
.hs { display: flex; gap: 20px; }
.hp { color: #00d4aa; }
.hd { color: #4dabf7; }
.hu { color: #ffa500; }

/* Footer */
.footer {
  text-align: center;
  padding: 20px;
  font-size: 12px;
  color: #333;
  border-top: 1px solid rgba(255,255,255,0.04);
}

/* Responsive */
@media (max-width: 700px) {
  .cards { grid-template-columns: repeat(2, 1fr); gap: 10px; }
  .card { padding: 16px 10px; }
  .c-val { font-size: 22px; }
  .gauge-wrap { width: 260px; height: 155px; }
  .speed-num { font-size: 44px; }
  .go-btn { width: 130px; height: 130px; font-size: 22px; }
  .info { flex-wrap: wrap; justify-content: center; }
}
@media (max-width: 400px) {
  .cards { grid-template-columns: 1fr 1fr; }
  .gauge-wrap { width: 220px; height: 130px; }
  .speed-num { font-size: 36px; }
}