:root {
  --ink: #17202a;
  --muted: #64707d;
  --line: #d9e0e7;
  --surface: #f7f8fa;
  --panel: #ffffff;
  --green: #0f8a5f;
  --red: #c0392b;
  --amber: #b87300;
  --blue: #2563a8;
}

body {
  min-height: 100vh;
  color: var(--ink);
  background: var(--surface);
}

.app-shell {
  min-height: 100vh;
}

.top-band {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 24px;
  padding: 36px clamp(16px, 4vw, 56px) 24px;
  background: #ffffff;
  border-bottom: 1px solid var(--line);
}

.eyebrow {
  margin: 0 0 4px;
  color: var(--blue);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0;
  text-transform: uppercase;
}

h1 {
  margin: 0;
  font-size: clamp(2rem, 4vw, 4.2rem);
  font-weight: 800;
  letter-spacing: 0;
}

h2 {
  margin: 0;
  font-size: 1.25rem;
  font-weight: 750;
  letter-spacing: 0;
}

.connection-pill {
  min-width: 112px;
  padding: 8px 12px;
  color: #ffffff;
  text-align: center;
  background: #59636f;
  border-radius: 6px;
  font-weight: 700;
}

.connection-pill.running {
  background: var(--blue);
}

.connection-pill.ok {
  background: var(--green);
}

.connection-pill.error {
  background: var(--red);
}

.test-layout {
  display: grid;
  grid-template-columns: minmax(300px, 420px) minmax(0, 1fr);
  gap: 24px;
  padding: 24px clamp(16px, 4vw, 56px) 40px;
}

.control-panel,
.results-panel {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.control-panel {
  padding: 20px;
}

.panel-header {
  display: grid;
  grid-template-columns: 1fr auto auto;
  align-items: center;
  gap: 10px;
  margin-bottom: 18px;
}

.preset-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 8px;
  margin-bottom: 20px;
}

.preset-button {
  min-height: 44px;
  padding: 8px 10px;
  color: var(--ink);
  background: #eef2f5;
  border: 1px solid #cbd5de;
  border-radius: 6px;
  font-weight: 700;
}

.preset-button.active {
  color: #ffffff;
  background: var(--blue);
  border-color: var(--blue);
}

.setting-grid {
  display: grid;
  gap: 18px;
}

.field {
  display: grid;
  grid-template-columns: 1fr 96px;
  gap: 6px 12px;
  margin: 0;
}

.field span {
  grid-column: 1 / -1;
  color: var(--muted);
  font-size: 0.88rem;
  font-weight: 700;
}

.field .form-range {
  grid-column: 1;
  align-self: center;
}

.field .form-control {
  grid-column: 2;
  min-height: 38px;
}

.field small {
  grid-column: 1 / -1;
  color: var(--muted);
}

.results-panel {
  min-width: 0;
  padding: 20px;
}

.metric-row {
  display: grid;
  grid-template-columns: repeat(4, minmax(120px, 1fr));
  gap: 12px;
  margin-bottom: 14px;
}

.metric,
.latency-grid > div {
  padding: 14px;
  background: #f4f6f8;
  border: 1px solid #e1e6eb;
  border-radius: 8px;
}

.metric span,
.latency-grid span {
  display: block;
  margin-bottom: 4px;
  color: var(--muted);
  font-size: 0.82rem;
  font-weight: 700;
}

.metric strong {
  font-size: clamp(1.25rem, 2.2vw, 2rem);
  letter-spacing: 0;
}

.latency-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(100px, 1fr));
  gap: 12px;
  margin-bottom: 18px;
}

.latency-grid strong {
  font-size: 1.05rem;
}

.chart-wrap {
  width: 100%;
  aspect-ratio: 3 / 1;
  min-height: 220px;
  background: #fbfcfd;
  border: 1px solid var(--line);
  border-radius: 8px;
  overflow: hidden;
}

#result-chart {
  display: block;
  width: 100%;
  height: 100%;
}

.status-line {
  min-height: 28px;
  margin-top: 14px;
  color: var(--muted);
  font-weight: 650;
}

.status-line.error {
  color: var(--red);
}

button,
input {
  letter-spacing: 0;
}

@media (max-width: 920px) {
  .test-layout {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 680px) {
  .top-band {
    align-items: start;
    flex-direction: column;
  }

  .panel-header {
    grid-template-columns: 1fr 1fr;
  }

  .panel-header h2 {
    grid-column: 1 / -1;
  }

  .panel-header .btn {
    width: 100%;
  }

  .preset-grid,
  .metric-row,
  .latency-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 460px) {
  .preset-grid,
  .metric-row,
  .latency-grid {
    grid-template-columns: 1fr;
  }
}