:root {
  --bg: #f6f7f9;
  --surface: #ffffff;
  --surface-2: #f0f2f5;
  --border: #dde1e7;
  --text: #16191f;
  --muted: #5d6573;
  --accent: #1f7a5a;
  --accent-strong: #16664a;
  --accent-soft: #e3f3ec;
  --on-accent: #ffffff;
  --danger: #b42318;
  --danger-soft: #fdeceb;
  --focus: #2563eb;
  --shadow: 0 1px 2px rgba(16, 24, 40, .06), 0 1px 3px rgba(16, 24, 40, .08);
  --radius: 12px;
  --mono: ui-monospace, "SF Mono", "Cascadia Code", "Segoe UI Mono", Menlo, Consolas, monospace;
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0f1216;
    --surface: #171b21;
    --surface-2: #1f242c;
    --border: #2c333d;
    --text: #e8ebf0;
    --muted: #9aa3b2;
    --accent: #3fb68b;
    --accent-strong: #5cc9a0;
    --accent-soft: #15302a;
    --on-accent: #06140f;
    --danger: #f0776c;
    --danger-soft: #3a1a18;
    --focus: #7aa2ff;
    --shadow: none;
    color-scheme: dark;
  }
}

:root[data-theme="dark"] {
  --bg: #0f1216;
  --surface: #171b21;
  --surface-2: #1f242c;
  --border: #2c333d;
  --text: #e8ebf0;
  --muted: #9aa3b2;
  --accent: #3fb68b;
  --accent-strong: #5cc9a0;
  --accent-soft: #15302a;
  --on-accent: #06140f;
  --danger: #f0776c;
  --danger-soft: #3a1a18;
  --focus: #7aa2ff;
  --shadow: none;
  color-scheme: dark;
}

*, *::before, *::after { box-sizing: border-box; }
[hidden] { display: none !important; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.55 system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

a { color: var(--accent); }
a:hover { color: var(--accent-strong); }
:focus-visible { outline: 2px solid var(--focus); outline-offset: 2px; }

.wrap { max-width: 760px; margin: 0 auto; padding: 0 16px; }
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.muted { color: var(--muted); }

/* Header */
.site-header { border-bottom: 1px solid var(--border); background: var(--surface); }
.header-inner { display: flex; align-items: center; justify-content: space-between; height: 60px; gap: 16px; }
.brand { display: inline-flex; align-items: center; gap: 10px; font-weight: 700; font-size: 18px; color: var(--text); text-decoration: none; }
.brand-mark { width: 28px; height: 28px; }
.brand-mark .on { fill: var(--accent); }
.brand-mark .off { fill: none; stroke: var(--accent); stroke-width: 1.5; }

/* Intro */
.intro { padding: 36px 0 4px; }
.intro h1 { font-size: clamp(26px, 4vw, 36px); line-height: 1.15; margin: 0 0 12px; letter-spacing: -0.01em; }
.intro p { margin: 0; color: var(--muted); font-size: 17px; }
.intro strong { color: var(--text); }

.banner {
  display: flex; align-items: center; gap: 10px; margin: 16px 0 0;
  padding: 10px 14px; border-radius: 10px; font-size: 14.5px;
  background: var(--surface-2); border: 1px solid var(--border);
}
.spinner {
  width: 16px; height: 16px; flex: none; border-radius: 50%;
  border: 2px solid var(--border); border-top-color: var(--accent);
  animation: spin .8s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* Cards */
.card {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  box-shadow: var(--shadow); padding: 22px; margin-top: 20px;
}
.card h2 { font-size: 18px; margin: 0 0 14px; }
.card > p.muted { margin: -6px 0 14px; font-size: 14.5px; }

/* Forms */
input[type="text"] {
  width: 100%; min-width: 0; font: inherit; color: var(--text); background: var(--surface);
  border: 1px solid var(--border); border-radius: 10px; padding: 11px 13px;
}
input[type="text"]::placeholder { color: var(--muted); opacity: .75; }
input[type="text"]:focus { outline: none; border-color: var(--focus); box-shadow: 0 0 0 3px color-mix(in srgb, var(--focus) 22%, transparent); }

.url-form { display: flex; gap: 10px; }
.url-form input { font-family: var(--mono); font-size: 15px; }

.btn {
  font: inherit; font-weight: 600; border-radius: 10px; padding: 11px 18px; cursor: pointer;
  border: 1px solid var(--border); background: var(--surface-2); color: var(--text); white-space: nowrap;
}
.btn:hover { border-color: var(--muted); }
.btn.primary { background: var(--accent); border-color: var(--accent); color: var(--on-accent); }
.btn.primary:hover { background: var(--accent-strong); border-color: var(--accent-strong); }
.btn[disabled] { opacity: .6; cursor: progress; }

.examples { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; margin-top: 10px; font-size: 13.5px; color: var(--muted); }
.chip {
  font: inherit; font-size: 13px; padding: 3px 10px; border-radius: 999px; cursor: pointer;
  border: 1px solid var(--border); background: var(--surface-2); color: var(--text);
}
.chip:hover { border-color: var(--muted); }

.form-error { margin-top: 12px; padding: 10px 12px; border-radius: 10px; background: var(--danger-soft); color: var(--danger); font-size: 14.5px; }
.form-result { margin-top: 14px; padding: 12px 14px; border-radius: 10px; font-size: 14.5px; }
.form-result.ok { background: var(--accent-soft); }
.form-result.err { background: var(--danger-soft); color: var(--danger); }

/* Result */
.result { margin-top: 20px; padding-top: 18px; border-top: 1px solid var(--border); }
.verdict { display: inline-block; font-weight: 700; font-size: 15px; padding: 5px 12px; border-radius: 999px; }
.verdict.bad { background: var(--danger-soft); color: var(--danger); }
.verdict.good { background: var(--accent-soft); color: var(--accent); }
.result-message { margin: 12px 0 14px; }

/* One box per bit: filled = 1, outlined = 0 (matches the logo). */
.bits { list-style: none; padding: 0; margin: 0; display: flex; gap: 6px; }
.bits li {
  flex: 0 1 36px; min-width: 0; height: 40px; display: grid; place-items: center; border-radius: 8px;
  font-family: var(--mono); font-size: 17px; font-weight: 700;
}
.bits li.on { background: var(--accent); color: var(--on-accent); }
.bits li.off { border: 2px solid var(--accent); color: var(--accent); }

/* Stats */
.stats { margin-top: 20px; }
.kpis { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 10px; margin: 0; }
@media (max-width: 640px) { .kpis { grid-template-columns: repeat(2, minmax(0, 1fr)); } }
.kpis > div { background: var(--surface); border: 1px solid var(--border); border-radius: 10px; padding: 12px 14px; }
.kpis dt { font-size: 12.5px; color: var(--muted); }
.kpis dd { margin: 2px 0 0; font-size: 20px; font-weight: 700; font-variant-numeric: tabular-nums; }
.kpi-note { margin: 0; font-size: 12.5px; color: var(--muted); }

/* How it works */
.how { padding: 28px 0 0; }
.how h2 { font-size: 20px; margin: 0 0 14px; }
.steps { list-style: none; padding: 0; margin: 0; display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 12px; }
@media (max-width: 640px) { .steps { grid-template-columns: minmax(0, 1fr); } }
.steps li { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 14px 16px; }
.steps h3 { font-size: 15px; margin: 0 0 4px; }
.steps p { margin: 0; font-size: 14.5px; color: var(--muted); }

.site-footer { border-top: 1px solid var(--border); margin-top: 32px; padding: 18px 0 28px; font-size: 13.5px; color: var(--muted); }

@media (max-width: 520px) {
  .url-form { flex-direction: column; }
  .card { padding: 18px 16px; }
}

@media (prefers-reduced-motion: reduce) {
  .spinner { animation-duration: 2.4s; }
}