:root {
  --bg: #07111f;
  --bg-soft: #0d1b2a;
  --card: rgba(17, 26, 41, 0.92);
  --card-border: rgba(148, 163, 184, 0.18);
  --primary: #60a5fa;
  --primary-strong: #3b82f6;
  --success: #34d399;
  --warning: #fbbf24;
  --text: #e5eefb;
  --muted: #a8b6d0;
  --shadow: rgba(2, 6, 23, 0.45);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  display: grid;
  place-items: center;
  background:
    radial-gradient(circle at top, rgba(96, 165, 250, 0.2), transparent 30%),
    linear-gradient(135deg, var(--bg), var(--bg-soft));
  color: var(--text);
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
}

.app-shell {
  width: min(92vw, 760px);
}

.speed-card {
  background: var(--card);
  border: 1px solid var(--card-border);
  border-radius: 24px;
  box-shadow: 0 24px 70px var(--shadow);
  padding: 32px 28px;
  backdrop-filter: blur(12px);
}

.eyebrow {
  margin: 0 0 8px;
  color: var(--primary);
  text-transform: uppercase;
  letter-spacing: 0.12em;
  font-size: 0.72rem;
  font-weight: 700;
}

.header-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 20px;
}

h1 {
  margin: 0;
  font-size: clamp(2rem, 3vw, 3rem);
  line-height: 1.1;
}

.exit-btn {
  border: 0;
  border-radius: 999px;
  background: rgba(148, 163, 184, 0.18);
  color: var(--text);
  padding: 10px 14px;
  cursor: pointer;
  font-weight: 700;
}

.status-row {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 10px 14px;
  border-radius: 999px;
  background: rgba(96, 165, 250, 0.09);
  border: 1px solid rgba(96, 165, 250, 0.22);
  color: var(--muted);
  margin-bottom: 28px;
}

.status-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--success);
  box-shadow: 0 0 12px rgba(52, 211, 153, 0.9);
}

.metrics-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(120px, 1fr));
  gap: 16px;
  margin-bottom: 20px;
}

.metric-box {
  background: rgba(15, 23, 42, 0.8);
  border: 1px solid rgba(148, 163, 184, 0.12);
  border-radius: 18px;
  padding: 18px 16px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.metric-label {
  color: var(--muted);
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.metric-box strong {
  font-size: clamp(1.5rem, 2vw, 2.2rem);
  line-height: 1;
  font-weight: 800;
}

.metric-box small {
  color: var(--muted);
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.primary-btn {
  width: 100%;
  border: 0;
  border-radius: 14px;
  background: linear-gradient(135deg, var(--primary), var(--primary-strong));
  color: white;
  font-size: 1rem;
  font-weight: 700;
  padding: 16px 18px;
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
  box-shadow: 0 12px 28px rgba(59, 130, 246, 0.32);
}

.primary-btn:hover {
  transform: translateY(-1px);
}

.primary-btn:active {
  transform: translateY(0);
}

.primary-btn:disabled {
  cursor: wait;
  opacity: 0.75;
}

.progress-track {
  width: 100%;
  height: 12px;
  border-radius: 999px;
  background: rgba(148, 163, 184, 0.12);
  overflow: hidden;
  margin-top: 24px;
  margin-bottom: 18px;
}

.progress-bar {
  width: 0%;
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--success), var(--primary));
  transition: width 0.4s ease;
}

.result-text {
  margin: 0;
  color: var(--muted);
  min-height: 48px;
  line-height: 1.5;
}

@media (max-width: 560px) {
  .speed-card {
    padding: 24px 18px;
  }

  .metrics-grid {
    grid-template-columns: 1fr;
  }
}