:root {
  color-scheme: light;
  --bg: #f8fafc;
  --bg-soft: #eef5f6;
  --surface: #ffffff;
  --surface-raised: #f3f8fb;
  --text: #0f172a;
  --muted: #526071;
  --subtle: #7a8899;
  --border: rgba(30, 58, 95, 0.16);
  --primary: #1e3a5f;
  --primary-strong: #16304e;
  --secondary: #2563eb;
  --accent: #059669;
  --warning: #d97706;
  --danger: #dc2626;
  --ring: rgba(37, 99, 235, 0.32);
  --shadow: 0 18px 48px rgba(15, 23, 42, 0.12);
  --shadow-soft: 0 10px 28px rgba(15, 23, 42, 0.08);
  --radius: 8px;
  --ease: cubic-bezier(0.16, 1, 0.3, 1);
  --header-height: 72px;
  --font-body: "Fira Sans", "Microsoft YaHei", "PingFang SC", "Segoe UI", system-ui, sans-serif;
  --font-data: "Fira Code", "SFMono-Regular", Consolas, monospace;
}

:root[data-theme="dark"] {
  color-scheme: dark;
  --bg: #101419;
  --bg-soft: #141d22;
  --surface: #161d24;
  --surface-raised: #1c2730;
  --text: #eff6ff;
  --muted: #a7b4c5;
  --subtle: #7f8d9e;
  --border: rgba(148, 163, 184, 0.22);
  --primary: #60a5fa;
  --primary-strong: #93c5fd;
  --secondary: #38bdf8;
  --accent: #34d399;
  --warning: #fbbf24;
  --danger: #f87171;
  --ring: rgba(56, 189, 248, 0.36);
  --shadow: 0 20px 54px rgba(0, 0, 0, 0.34);
  --shadow-soft: 0 14px 34px rgba(0, 0, 0, 0.24);
}

* {
  box-sizing: border-box;
}

html {
  min-width: 320px;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100dvh;
  background:
    linear-gradient(145deg, color-mix(in srgb, var(--secondary) 14%, transparent), transparent 34rem),
    linear-gradient(315deg, color-mix(in srgb, var(--accent) 12%, transparent), transparent 32rem),
    linear-gradient(180deg, var(--bg), var(--bg-soft));
  color: var(--text);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  overflow-x: hidden;
  text-rendering: optimizeLegibility;
}

body::before {
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  content: "";
  background-image:
    linear-gradient(color-mix(in srgb, var(--border) 42%, transparent) 1px, transparent 1px),
    linear-gradient(90deg, color-mix(in srgb, var(--border) 42%, transparent) 1px, transparent 1px);
  background-size: 44px 44px;
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.8), transparent 76%);
}

a {
  color: inherit;
  text-decoration: none;
}

button,
input {
  font: inherit;
}

button {
  cursor: pointer;
}

button:disabled {
  cursor: not-allowed;
  opacity: 0.54;
}

:focus-visible {
  outline: 3px solid var(--ring);
  outline-offset: 3px;
}

.skip-link {
  position: fixed;
  left: 16px;
  top: 12px;
  z-index: 1000;
  padding: 10px 14px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transform: translateY(-140%);
  transition: transform 180ms var(--ease);
}

.skip-link:focus {
  transform: translateY(0);
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  min-height: var(--header-height);
  border-bottom: 1px solid var(--border);
  background: color-mix(in srgb, var(--bg) 86%, transparent);
  backdrop-filter: blur(18px);
}

.top-nav {
  width: min(1180px, calc(100% - 32px));
  min-height: var(--header-height);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  min-height: 44px;
  font-weight: 700;
}

.brand-mark {
  width: 34px;
  height: 34px;
  display: inline-grid;
  place-items: center;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: #fff;
  font-family: var(--font-data);
  font-size: 13px;
  letter-spacing: 0;
  box-shadow: var(--shadow-soft);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-link,
.theme-toggle,
.ghost-button,
.refresh-button,
.sort-button,
.metric-toggle {
  min-height: 44px;
  border: 1px solid transparent;
  border-radius: var(--radius);
  background: transparent;
  color: var(--muted);
  transition:
    transform 180ms var(--ease),
    border-color 180ms var(--ease),
    background-color 180ms var(--ease),
    color 180ms var(--ease),
    box-shadow 180ms var(--ease);
  touch-action: manipulation;
}

.nav-link,
.theme-toggle,
.ghost-button,
.refresh-button,
.metric-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 0 14px;
  font-weight: 600;
}

.nav-link:hover,
.theme-toggle:hover,
.ghost-button:hover,
.refresh-button:hover,
.metric-toggle:hover {
  transform: translateY(-1px);
  border-color: var(--border);
  background: color-mix(in srgb, var(--surface-raised) 76%, transparent);
  color: var(--text);
}

body[data-page="home"] [data-nav="home"],
body[data-page="results"] [data-nav="results"],
body[data-page="chart"] [data-nav="chart"],
.metric-toggle.is-active {
  border-color: color-mix(in srgb, var(--primary) 42%, var(--border));
  background: color-mix(in srgb, var(--primary) 12%, var(--surface));
  color: var(--primary-strong);
}

.page-shell {
  width: min(1180px, calc(100% - 32px));
  margin: 0 auto;
  padding: 48px 0 64px;
}

.hero-dashboard,
.page-heading,
.network-panel,
.data-panel,
.chart-panel {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: color-mix(in srgb, var(--surface) 92%, transparent);
  box-shadow: var(--shadow);
}

.hero-dashboard {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(320px, 0.74fr);
  gap: 28px;
  align-items: center;
  padding: clamp(24px, 4vw, 48px);
  overflow: hidden;
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--accent);
  font-family: var(--font-data);
  font-size: 13px;
  font-weight: 600;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  max-width: 780px;
  margin-bottom: 14px;
  font-size: clamp(36px, 6vw, 68px);
  line-height: 1.04;
  letter-spacing: 0;
}

.hero-copy p,
.page-heading p {
  max-width: 720px;
  margin-bottom: 0;
  color: var(--muted);
  font-size: 18px;
}

.control-panel {
  position: relative;
  display: grid;
  gap: 18px;
  padding: 22px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background:
    linear-gradient(180deg, color-mix(in srgb, var(--surface-raised) 80%, transparent), color-mix(in srgb, var(--surface) 94%, transparent));
}

.status-line,
.panel-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  color: var(--muted);
}

.status-line strong,
.panel-row strong {
  color: var(--text);
  font-family: var(--font-data);
  font-weight: 600;
}

.progress-track {
  position: relative;
  height: 12px;
  overflow: hidden;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: color-mix(in srgb, var(--surface-raised) 82%, var(--bg));
}

.progress-fill {
  width: 0%;
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--secondary), var(--accent));
  transition: width 420ms var(--ease);
}

.progress-fill::after {
  display: block;
  width: 100%;
  height: 100%;
  content: "";
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.42), transparent);
  animation: scanLine 1.9s linear infinite;
}

.primary-action {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 54px;
  padding: 0 22px;
  border: 0;
  border-radius: var(--radius);
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  color: #fff;
  font-weight: 700;
  box-shadow: 0 18px 34px color-mix(in srgb, var(--primary) 32%, transparent);
  transition:
    transform 180ms var(--ease),
    box-shadow 180ms var(--ease),
    background 180ms var(--ease);
}

.primary-action:hover {
  transform: translateY(-2px);
  box-shadow: 0 22px 42px color-mix(in srgb, var(--primary) 38%, transparent);
}

.primary-action:active {
  transform: scale(0.98);
}

.primary-action.is-running {
  background: linear-gradient(135deg, #b91c1c, var(--danger));
  box-shadow: 0 18px 34px color-mix(in srgb, var(--danger) 34%, transparent);
}

.button-spinner {
  display: none;
  width: 18px;
  height: 18px;
  margin-left: 10px;
  border: 2px solid rgba(255, 255, 255, 0.38);
  border-top-color: #fff;
  border-radius: 999px;
  animation: spin 780ms linear infinite;
}

.primary-action.is-running .button-spinner {
  display: inline-block;
}

.metric-grid,
.summary-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
  margin-top: 16px;
}

.metric-card,
.summary-card {
  min-height: 184px;
  padding: 20px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: color-mix(in srgb, var(--surface) 94%, transparent);
  box-shadow: var(--shadow-soft);
  transition:
    transform 220ms var(--ease),
    border-color 220ms var(--ease),
    box-shadow 220ms var(--ease);
}

.metric-card:hover,
.summary-card:hover {
  transform: translateY(-3px);
  border-color: color-mix(in srgb, var(--primary) 38%, var(--border));
}

.metric-card.is-active {
  border-color: color-mix(in srgb, var(--accent) 58%, var(--border));
  box-shadow: 0 18px 38px color-mix(in srgb, var(--accent) 18%, transparent);
}

.metric-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 18px;
}

.metric-kicker,
.summary-label,
.table-meta,
.chart-meta {
  color: var(--subtle);
  font-family: var(--font-data);
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
}

.metric-card h2 {
  margin: 4px 0 0;
  font-size: 18px;
  line-height: 1.25;
}

.signal-bars {
  display: inline-flex;
  align-items: flex-end;
  gap: 3px;
  width: 36px;
  height: 28px;
}

.signal-bars i {
  display: block;
  width: 6px;
  border-radius: 999px;
  background: currentColor;
  opacity: 0.74;
}

.signal-bars i:nth-child(1) {
  height: 10px;
}

.signal-bars i:nth-child(2) {
  height: 17px;
}

.signal-bars i:nth-child(3) {
  height: 25px;
}

.metric-card.is-active .signal-bars i {
  animation: barDance 700ms var(--ease) infinite alternate;
}

.metric-card.is-active .signal-bars i:nth-child(2) {
  animation-delay: 90ms;
}

.metric-card.is-active .signal-bars i:nth-child(3) {
  animation-delay: 180ms;
}

.metric-value,
.summary-value {
  display: flex;
  align-items: baseline;
  gap: 8px;
}

.meterText,
.summary-number {
  font-family: var(--font-data);
  font-size: clamp(34px, 5vw, 46px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: 0;
  font-variant-numeric: tabular-nums;
}

.meterText:empty::before {
  content: "0.00";
  color: var(--subtle);
}

.unit {
  color: var(--muted);
  font-family: var(--font-data);
  font-size: 13px;
  font-weight: 600;
}

[data-metric="download"] {
  color: var(--secondary);
}

[data-metric="upload"] {
  color: var(--accent);
}

[data-metric="ping"] {
  color: var(--warning);
}

[data-metric="jitter"] {
  color: var(--danger);
}

.network-panel {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  margin-top: 16px;
  padding: 18px 20px;
}

.network-label {
  display: block;
  color: var(--subtle);
  font-size: 13px;
  font-weight: 700;
}

.network-value {
  display: block;
  margin-top: 2px;
  font-family: var(--font-data);
  font-size: 15px;
  color: var(--text);
  word-break: break-word;
}

.page-heading {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 24px;
  padding: clamp(22px, 4vw, 36px);
}

.page-heading h1 {
  margin-bottom: 10px;
  font-size: clamp(32px, 5vw, 52px);
}

.toolbar {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 10px;
  flex-wrap: wrap;
}

.search-field {
  width: min(320px, 100%);
  min-height: 44px;
  padding: 0 14px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  color: var(--text);
  transition: border-color 180ms var(--ease), box-shadow 180ms var(--ease);
}

.search-field:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 4px var(--ring);
  outline: 0;
}

.summary-card {
  min-height: 132px;
}

.summary-label {
  display: block;
  margin-bottom: 18px;
}

.data-panel,
.chart-panel {
  margin-top: 16px;
  padding: 20px;
}

.table-wrap {
  width: 100%;
}

.data-table {
  width: 100%;
  border-collapse: collapse;
}

.data-table th,
.data-table td {
  padding: 14px 12px;
  border-bottom: 1px solid var(--border);
  text-align: left;
  vertical-align: middle;
}

.data-table th {
  color: var(--muted);
  font-size: 13px;
  font-weight: 700;
}

.data-table td {
  color: var(--text);
}

.data-table td[data-align="right"] {
  text-align: right;
  font-family: var(--font-data);
  font-variant-numeric: tabular-nums;
}

.sort-button {
  min-height: 32px;
  padding: 0;
  color: inherit;
  font-weight: 700;
}

.sort-button::after {
  content: "";
  display: inline-block;
  width: 7px;
  height: 7px;
  margin-left: 8px;
  border-right: 2px solid currentColor;
  border-bottom: 2px solid currentColor;
  transform: rotate(45deg) translateY(-2px);
  opacity: 0.38;
}

th[aria-sort="ascending"] .sort-button::after {
  transform: rotate(225deg) translateY(-1px);
  opacity: 1;
}

th[aria-sort="descending"] .sort-button::after {
  opacity: 1;
}

.empty-state,
.loading-state,
.error-state {
  display: grid;
  place-items: center;
  min-height: 220px;
  color: var(--muted);
  text-align: center;
}

.is-hidden,
[hidden] {
  display: none !important;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.summary-text {
  min-width: 0;
  max-width: 100%;
  font-family: var(--font-body);
  font-size: clamp(20px, 3vw, 30px);
  overflow-wrap: anywhere;
}

.chart-panel {
  min-height: 560px;
}

.chart-shell {
  position: relative;
  height: 480px;
  min-height: 360px;
}

.chart-shell canvas {
  width: 100% !important;
  height: 100% !important;
}

.segmented {
  display: inline-flex;
  gap: 6px;
  padding: 4px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: color-mix(in srgb, var(--surface-raised) 72%, transparent);
}

.metric-toggle {
  min-height: 38px;
  padding: 0 12px;
}

.site-footer {
  width: min(1180px, calc(100% - 32px));
  margin: 0 auto;
  padding: 0 0 36px;
  color: var(--muted);
  text-align: center;
}

.site-footer a {
  color: var(--primary-strong);
  font-weight: 700;
}

.reveal {
  animation: fadeUp 520ms var(--ease) both;
}

.metric-card:nth-child(1),
.summary-card:nth-child(1) {
  animation-delay: 40ms;
}

.metric-card:nth-child(2),
.summary-card:nth-child(2) {
  animation-delay: 90ms;
}

.metric-card:nth-child(3),
.summary-card:nth-child(3) {
  animation-delay: 140ms;
}

.metric-card:nth-child(4),
.summary-card:nth-child(4) {
  animation-delay: 190ms;
}

@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(16px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes scanLine {
  from {
    transform: translateX(-100%);
  }
  to {
    transform: translateX(100%);
  }
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

@keyframes barDance {
  from {
    transform: scaleY(0.62);
    opacity: 0.52;
  }
  to {
    transform: scaleY(1);
    opacity: 1;
  }
}

@media (max-width: 920px) {
  .top-nav,
  .network-panel,
  .page-heading {
    align-items: stretch;
    flex-direction: column;
  }

  .nav-actions,
  .toolbar {
    justify-content: flex-start;
  }

  .hero-dashboard {
    grid-template-columns: 1fr;
  }

  .metric-grid,
  .summary-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 720px) {
  .page-shell {
    width: min(100% - 24px, 1180px);
    padding-top: 28px;
  }

  .nav-actions {
    width: 100%;
    overflow-x: auto;
    padding-bottom: 4px;
  }

  .nav-link,
  .theme-toggle {
    flex: 0 0 auto;
  }

  .metric-grid,
  .summary-grid {
    grid-template-columns: 1fr;
  }

  .hero-dashboard,
  .page-heading,
  .data-panel,
  .chart-panel {
    padding: 18px;
  }

  .data-table thead {
    display: none;
  }

  .data-table,
  .data-table tbody,
  .data-table tr,
  .data-table td {
    display: block;
    width: 100%;
  }

  .data-table tr {
    padding: 12px 0;
    border-bottom: 1px solid var(--border);
  }

  .data-table td {
    display: flex;
    justify-content: space-between;
    gap: 16px;
    padding: 8px 0;
    border: 0;
    text-align: right;
  }

  .data-table td::before {
    content: attr(data-label);
    color: var(--muted);
    font-family: var(--font-body);
    font-weight: 700;
    text-align: left;
  }

  .chart-panel {
    min-height: 440px;
  }

  .chart-shell {
    height: 360px;
  }
}

@media (max-width: 460px) {
  .top-nav {
    width: min(100% - 20px, 1180px);
  }

  .page-shell {
    width: min(100% - 20px, 1180px);
  }

  .control-panel {
    padding: 16px;
  }

  .segmented {
    width: 100%;
    flex-wrap: wrap;
  }

  .metric-toggle {
    flex: 1 1 calc(50% - 6px);
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
  }
}