:root {
  color-scheme: dark light;

  --bg: #0a0a0b;
  --bg-elev: #111114;
  --bg-elev-2: #16161a;
  --bg-input: #0f0f12;
  --border: rgba(255, 255, 255, 0.06);
  --border-strong: rgba(255, 255, 255, 0.10);
  --border-focus: rgba(255, 255, 255, 0.25);

  --text: #fafafa;
  --text-muted: #a1a1aa;
  --text-subtle: #71717a;
  --text-faint: #52525b;

  --accent: #10b981;
  --accent-2: #22d3ee;
  --accent-glow: rgba(16, 185, 129, 0.18);

  --danger: #f87171;
  --warning: #fbbf24;
  --info: #60a5fa;
  --success: #4ade80;

  --r-sm: 6px;
  --r: 8px;
  --r-lg: 12px;
  --r-xl: 16px;

  --font-sans: "Geist", ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --font-mono: "Geist Mono", ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
}

@media (prefers-color-scheme: light) {
  :root {
    --bg: #fafafa;
    --bg-elev: #ffffff;
    --bg-elev-2: #f4f4f5;
    --bg-input: #ffffff;
    --border: rgba(0, 0, 0, 0.07);
    --border-strong: rgba(0, 0, 0, 0.12);
    --border-focus: rgba(0, 0, 0, 0.35);
    --text: #09090b;
    --text-muted: #52525b;
    --text-subtle: #71717a;
    --text-faint: #a1a1aa;
    --accent: #059669;
    --accent-glow: rgba(5, 150, 105, 0.14);
  }
}

* { box-sizing: border-box; }

html, body {
  height: 100%;
  margin: 0;
}

body {
  font-family: var(--font-sans);
  font-size: 14px;
  line-height: 1.55;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

a { color: inherit; text-decoration: none; }
button { font-family: inherit; cursor: pointer; }
code, pre { font-family: var(--font-mono); font-size: 12.5px; }

::selection { background: var(--accent); color: #fff; }

.hidden { display: none !important; }

/* ============================================================
   BACKGROUND
   ============================================================ */

.grid-bg {
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background-image:
    radial-gradient(ellipse 80% 50% at 50% -20%, var(--accent-glow), transparent 70%),
    linear-gradient(to right, var(--border) 1px, transparent 1px),
    linear-gradient(to bottom, var(--border) 1px, transparent 1px);
  background-size: 100% 100%, 56px 56px, 56px 56px;
  background-position: 0 0, 0 0, 0 0;
  mask-image: radial-gradient(ellipse 100% 70% at 50% 0%, black 30%, transparent 80%);
  -webkit-mask-image: radial-gradient(ellipse 100% 70% at 50% 0%, black 30%, transparent 80%);
}

/* ============================================================
   NAV
   ============================================================ */

.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  background: color-mix(in srgb, var(--bg) 75%, transparent);
  border-bottom: 1px solid var(--border);
}

.nav-inner {
  max-width: 1080px;
  margin: 0 auto;
  padding: 14px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 500;
  letter-spacing: -0.01em;
  color: var(--text);
}

.brand-dot {
  width: 8px;
  height: 8px;
  border-radius: 2px;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  box-shadow: 0 0 12px var(--accent-glow);
}

.nav-right {
  display: flex;
  align-items: center;
  gap: 12px;
}

.nav-link {
  color: var(--text-muted);
  display: inline-flex;
  align-items: center;
  padding: 6px;
  border-radius: var(--r-sm);
  transition: color 150ms, background 150ms;
}
.nav-link:hover { color: var(--text); background: var(--bg-elev); }

.status-pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 11.5px;
  font-family: var(--font-mono);
  color: var(--text-muted);
  padding: 4px 9px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--bg-elev);
}

.status-dot {
  width: 6px;
  height: 6px;
  border-radius: 999px;
  background: var(--accent);
  box-shadow: 0 0 8px var(--accent);
  animation: pulse 2.4s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.55; transform: scale(0.85); }
}

/* ============================================================
   LAYOUT
   ============================================================ */

.main {
  max-width: 920px;
  margin: 0 auto;
  padding: 64px 24px 96px;
  display: flex;
  flex-direction: column;
  gap: 56px;
}

/* ============================================================
   HERO
   ============================================================ */

.hero {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: 24px;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  color: var(--text-muted);
  padding: 5px 12px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--bg-elev);
  letter-spacing: -0.005em;
}

.eyebrow-dot {
  width: 6px;
  height: 6px;
  border-radius: 999px;
  background: var(--accent);
  box-shadow: 0 0 8px var(--accent);
}

.hero-title {
  margin: 0;
  font-size: clamp(36px, 6vw, 60px);
  font-weight: 600;
  letter-spacing: -0.035em;
  line-height: 1.05;
  color: var(--text);
}

.hero-accent {
  background: linear-gradient(110deg, var(--accent) 0%, var(--accent-2) 60%, var(--accent) 100%);
  background-size: 200% auto;
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  animation: shine 6s ease-in-out infinite;
}

@keyframes shine {
  0%, 100% { background-position: 0% center; }
  50% { background-position: 100% center; }
}

.hero-sub {
  margin: 0;
  max-width: 52ch;
  font-size: 15.5px;
  color: var(--text-muted);
  line-height: 1.6;
}

/* ============================================================
   URL BUILDER
   ============================================================ */

.builder {
  width: 100%;
  max-width: 720px;
  margin-top: 8px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.builder-input {
  display: flex;
  align-items: stretch;
  border: 1px solid var(--border-strong);
  border-radius: var(--r-lg);
  background: var(--bg-input);
  overflow: hidden;
  transition: border-color 150ms, box-shadow 150ms;
}

.builder-input:focus-within {
  border-color: var(--accent);
  box-shadow: 0 0 0 4px var(--accent-glow);
}

.builder-prefix {
  display: inline-flex;
  align-items: center;
  padding: 0 12px 0 14px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  color: var(--text-faint);
  background: transparent;
  border-right: 1px solid var(--border);
  white-space: nowrap;
}

.builder-input input {
  flex: 1;
  min-width: 0;
  border: none;
  background: transparent;
  color: var(--text);
  font-family: var(--font-mono);
  font-size: 14px;
  padding: 14px 16px;
  outline: none;
}

.builder-input input::placeholder { color: var(--text-faint); }

.builder-output {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 8px 8px 14px;
  border: 1px solid var(--border);
  border-radius: var(--r-lg);
  background: var(--bg-elev);
}

.builder-output-code {
  flex: 1;
  min-width: 0;
  font-family: var(--font-mono);
  font-size: 12.5px;
  color: var(--text-muted);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.builder-output-code.ready { color: var(--text); }

.builder-actions {
  display: flex;
  gap: 6px;
  flex-shrink: 0;
}

/* ============================================================
   METRIC STRIP
   ============================================================ */

.hero-meta {
  margin-top: 12px;
}

.metric-strip {
  display: inline-flex;
  align-items: center;
  gap: 0;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--bg-elev);
  padding: 4px 6px 4px 4px;
  overflow: hidden;
}

.strip-item {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 5px 12px;
  font-size: 12px;
}

.strip-label {
  font-family: var(--font-mono);
  font-size: 10.5px;
  color: var(--text-subtle);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.strip-value {
  font-family: var(--font-mono);
  font-size: 12.5px;
  font-weight: 500;
  color: var(--text);
  font-variant-numeric: tabular-nums;
}

.strip-divider {
  width: 1px;
  height: 14px;
  background: var(--border);
}

.strip-refresh {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 26px;
  height: 26px;
  border-radius: 999px;
  background: transparent;
  color: var(--text-subtle);
  border: none;
  margin-left: 4px;
  transition: background 150ms, color 150ms;
}
.strip-refresh:hover { background: var(--bg-elev-2); color: var(--text); }
.strip-refresh:active .refresh-icon { animation: spin 600ms linear; }

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

/* ============================================================
   FEATURES
   ============================================================ */

.features {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}

.feature {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 18px;
  border: 1px solid var(--border);
  border-radius: var(--r-lg);
  background: var(--bg-elev);
  transition: border-color 200ms, transform 200ms;
}

.feature:hover {
  border-color: var(--border-strong);
  transform: translateY(-1px);
}

.feature-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: var(--r);
  background: var(--bg-elev-2);
  color: var(--accent);
  flex-shrink: 0;
}

.feature-title {
  margin: 0 0 2px;
  font-size: 14px;
  font-weight: 600;
  letter-spacing: -0.01em;
}

.feature-sub {
  margin: 0;
  font-size: 12.5px;
  color: var(--text-muted);
  line-height: 1.5;
}

/* ============================================================
   NOTICE
   ============================================================ */

.notice {
  padding: 14px 18px;
  border: 1px solid var(--border-strong);
  border-left: 3px solid var(--accent);
  border-radius: var(--r);
  background: var(--bg-elev);
  font-size: 13px;
  line-height: 1.6;
  color: var(--text-muted);
}

.notice strong { color: var(--text); font-weight: 600; }
.notice em { color: var(--text); font-style: normal; font-weight: 500; }

/* ============================================================
   CARD
   ============================================================ */

.card {
  border: 1px solid var(--border);
  border-radius: var(--r-xl);
  background: var(--bg-elev);
  overflow: hidden;
}

.card-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
  padding: 20px 24px;
  border-bottom: 1px solid var(--border);
}

.card-title {
  margin: 0;
  font-size: 16px;
  font-weight: 600;
  letter-spacing: -0.015em;
}

.card-sub {
  margin: 2px 0 0;
  font-size: 12.5px;
  color: var(--text-muted);
}

.card-tabs {
  display: inline-flex;
  gap: 2px;
  padding: 3px;
  background: var(--bg-elev-2);
  border: 1px solid var(--border);
  border-radius: var(--r);
}

.card-tab {
  font-size: 12.5px;
  font-weight: 500;
  color: var(--text-muted);
  background: transparent;
  border: none;
  padding: 6px 12px;
  border-radius: 5px;
  transition: color 150ms, background 150ms;
}

.card-tab:hover { color: var(--text); }

.card-tab.active {
  color: var(--text);
  background: var(--bg-elev);
  box-shadow: 0 1px 0 rgba(255, 255, 255, 0.04), 0 0 0 1px var(--border);
}

.card-body {
  padding: 24px;
}

/* ============================================================
   FORM
   ============================================================ */

.form {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.field {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.field-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

.field-action {
  align-items: stretch;
}
.field-action label { visibility: hidden; }
.field-action .action-btn { height: 100%; min-height: 38px; }

.field label {
  font-family: var(--font-mono);
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-subtle);
  font-weight: 500;
}

.field-hint {
  text-transform: none;
  letter-spacing: 0;
  color: var(--text-faint);
  font-size: 10.5px;
  margin-left: 4px;
}

input[type="text"],
input[type="url"],
textarea,
select {
  width: 100%;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--text);
  background: var(--bg-input);
  border: 1px solid var(--border-strong);
  border-radius: var(--r);
  padding: 10px 12px;
  line-height: 1.45;
  outline: none;
  transition: border-color 150ms, box-shadow 150ms;
}

textarea {
  resize: vertical;
  min-height: 88px;
  font-family: var(--font-mono);
}

input:focus,
textarea:focus,
select:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-glow);
}

input::placeholder,
textarea::placeholder { color: var(--text-faint); }

.select-wrap { position: relative; }
.select-wrap select {
  appearance: none;
  -webkit-appearance: none;
  padding-right: 32px;
  cursor: pointer;
}

.select-arrow {
  position: absolute;
  right: 10px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-subtle);
  pointer-events: none;
}

.headers-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.header-row {
  display: grid;
  grid-template-columns: 1fr 1fr auto;
  gap: 8px;
}

.form-actions {
  display: flex;
  gap: 8px;
  margin-top: 4px;
}

/* ============================================================
   BUTTONS
   ============================================================ */

.action-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  font-size: 12.5px;
  font-weight: 500;
  line-height: 1;
  padding: 9px 14px;
  border-radius: var(--r);
  background: var(--bg-elev-2);
  color: var(--text);
  border: 1px solid var(--border-strong);
  transition: background 150ms, border-color 150ms, transform 100ms;
}
.action-btn:hover { background: var(--bg-elev); border-color: var(--border-focus); }
.action-btn:active { transform: translateY(1px); }

.action-btn.primary {
  background: var(--text);
  color: var(--bg);
  border-color: var(--text);
}
.action-btn.primary:hover {
  background: color-mix(in srgb, var(--text) 85%, transparent);
  border-color: color-mix(in srgb, var(--text) 85%, transparent);
}

.action-btn.lg {
  padding: 11px 18px;
  font-size: 13px;
}

.action-btn.disabled {
  opacity: 0.45;
  cursor: not-allowed;
  pointer-events: auto;
}
.action-btn.disabled:hover {
  background: var(--bg-elev-2);
  border-color: var(--border-strong);
  transform: none;
}

.icon-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  background: var(--bg-elev-2);
  color: var(--text-muted);
  border: 1px solid var(--border);
  border-radius: var(--r-sm);
  transition: background 150ms, color 150ms, border-color 150ms;
}
.icon-btn:hover {
  background: var(--bg-elev);
  color: var(--text);
  border-color: var(--border-strong);
}

.link-btn {
  background: transparent;
  border: none;
  color: var(--text-muted);
  font-size: 12px;
  font-weight: 500;
  padding: 4px 0;
  transition: color 150ms;
  align-self: flex-start;
}
.link-btn:hover { color: var(--text); }

/* ============================================================
   TABS (inner)
   ============================================================ */

.inner-tabs {
  display: flex;
  gap: 0;
  border-bottom: 1px solid var(--border);
  margin: 4px 0 12px;
}

.inner-tab {
  position: relative;
  background: transparent;
  border: none;
  color: var(--text-subtle);
  font-size: 12.5px;
  font-weight: 500;
  padding: 8px 14px 10px;
  margin-bottom: -1px;
  border-bottom: 1.5px solid transparent;
  transition: color 150ms, border-color 150ms;
}

.inner-tab:hover { color: var(--text); }
.inner-tab.active {
  color: var(--text);
  border-bottom-color: var(--accent);
}

.tab-pane { display: none; }
.tab-pane.active { display: block; }

/* ============================================================
   RESPONSE
   ============================================================ */

.response {
  margin-top: 24px;
  padding-top: 24px;
  border-top: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.response-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
}

.section-label {
  font-family: var(--font-mono);
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-subtle);
  font-weight: 500;
}

.response-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border: 1px solid var(--border);
  border-radius: var(--r);
  background: var(--bg-elev-2);
  overflow: hidden;
}

.resp-cell {
  padding: 10px 14px;
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.resp-cell:last-child { border-right: none; }

.resp-label {
  font-family: var(--font-mono);
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-subtle);
}

.resp-value {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--text);
  font-variant-numeric: tabular-nums;
}

.body-controls {
  display: flex;
  justify-content: flex-end;
  gap: 12px;
  margin-bottom: 8px;
}

.code-block {
  margin: 0;
  padding: 14px 16px;
  border: 1px solid var(--border);
  border-radius: var(--r);
  background: var(--bg-input);
  color: var(--text);
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.65;
  max-height: 360px;
  overflow: auto;
  white-space: pre-wrap;
  word-break: break-word;
}

/* ============================================================
   CHARTS
   ============================================================ */

.charts-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}

.chart-block {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.chart {
  display: flex;
  flex-direction: column;
  gap: 10px;
  min-height: 120px;
}

.chart-placeholder {
  color: var(--text-faint);
  font-size: 12.5px;
  padding: 24px 0;
  text-align: center;
}

.chart-bar {
  display: flex;
  flex-direction: column;
  gap: 5px;
}

.chart-bar-info {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  font-size: 11.5px;
  font-family: var(--font-mono);
}

.chart-bar-label { color: var(--text); }
.chart-bar-value { color: var(--text-subtle); font-variant-numeric: tabular-nums; }

.chart-bar-container {
  width: 100%;
  height: 4px;
  background: var(--bg-elev-2);
  border-radius: 999px;
  overflow: hidden;
}

.chart-bar-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  border-radius: 999px;
  transition: width 280ms cubic-bezier(.2,.8,.2,1);
}

.chart-bar-fill.status-success { background: linear-gradient(90deg, var(--success), var(--accent)); }
.chart-bar-fill.status-redirect { background: linear-gradient(90deg, var(--info), var(--accent-2)); }
.chart-bar-fill.status-client-error { background: linear-gradient(90deg, var(--warning), #f97316); }
.chart-bar-fill.status-server-error { background: linear-gradient(90deg, var(--danger), #dc2626); }
.chart-bar-fill.status-unknown { background: var(--text-subtle); }

.chart-bar-label.status-success { color: var(--success); }
.chart-bar-label.status-redirect { color: var(--info); }
.chart-bar-label.status-client-error { color: var(--warning); }
.chart-bar-label.status-server-error { color: var(--danger); }

/* ============================================================
   FOOTER
   ============================================================ */

.footer {
  max-width: 1080px;
  margin: 0 auto;
  padding: 28px 24px 36px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  font-size: 12px;
  color: var(--text-subtle);
  border-top: 1px solid var(--border);
}

.footer-brand {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  color: var(--text-muted);
}

.footer-meta { font-family: var(--font-mono); font-size: 11.5px; }

.footer-credit {
  font-family: var(--font-mono);
  font-size: 11.5px;
  color: var(--text-subtle);
}

.footer-credit a {
  color: var(--text-muted);
  font-weight: 500;
  transition: color 150ms;
}
.footer-credit a:hover { color: var(--accent); }

.footer-heart {
  display: inline-block;
  animation: heartbeat 1.6s ease-in-out infinite;
  transform-origin: center;
}

@keyframes heartbeat {
  0%, 100% { transform: scale(1); }
  20% { transform: scale(1.2); }
  40% { transform: scale(0.95); }
  60% { transform: scale(1.1); }
}

/* ============================================================
   RESPONSIVE
   ============================================================ */

@media (max-width: 760px) {
  .main { padding: 40px 18px 64px; gap: 40px; }
  .nav-inner { padding: 12px 18px; }
  .hero-title { font-size: clamp(32px, 9vw, 44px); }
  .hero-sub { font-size: 14.5px; }
  .features { grid-template-columns: 1fr; }
  .card-body { padding: 18px; }
  .card-head { padding: 16px 18px; flex-direction: column; align-items: stretch; }
  .field-row { grid-template-columns: 1fr; }
  .response-stats { grid-template-columns: 1fr; }
  .resp-cell { border-right: none; border-bottom: 1px solid var(--border); }
  .resp-cell:last-child { border-bottom: none; }
  .charts-grid { grid-template-columns: 1fr; }
  .builder-prefix { display: none; }
  .builder-output { flex-wrap: wrap; }
  .footer { padding: 20px 18px 28px; flex-direction: column; align-items: flex-start; gap: 6px; }
}

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