/* shadcn/ui-style tokens (violet brand on zinc), reproduced without React or Tailwind.
   Theme: follows the OS unless <html data-theme="light|dark"> is set by the toggle. */
:root {
  --radius: 0.625rem;
  --background: oklch(0.992 0.004 286);
  --foreground: oklch(0.17 0.02 286);
  --card: oklch(1 0 0 / 0.72);
  --card-solid: oklch(1 0 0);
  --card-foreground: oklch(0.17 0.02 286);
  --primary: oklch(0.54 0.235 287);
  --primary-foreground: oklch(0.99 0 0);
  --secondary: oklch(0.955 0.015 287);
  --secondary-foreground: oklch(0.25 0.04 287);
  --muted: oklch(0.96 0.01 287);
  --muted-foreground: oklch(0.5 0.025 286);
  --accent: oklch(0.95 0.025 287);
  --destructive: oklch(0.577 0.245 27.325);
  --border: oklch(0.9 0.015 287);
  --input: oklch(0.88 0.018 287);
  --ring: oklch(0.6 0.2 287);

  /* Background hues and gradient stops */
  --hue-violet: oklch(0.72 0.19 292);
  --hue-cyan: oklch(0.82 0.12 210);
  --hue-pink: oklch(0.8 0.15 350);
  --hue-amber: oklch(0.86 0.13 80);
  --aurora: 28%;
  --g1: oklch(0.52 0.25 290);
  --g2: oklch(0.6 0.24 340);
  --g3: oklch(0.58 0.15 230);

  --tile-violet: oklch(0.55 0.22 292);
  --tile-rose: oklch(0.6 0.21 15);
  --tile-amber: oklch(0.66 0.16 65);
  --tile-red: oklch(0.58 0.22 30);
  --tile-sky: oklch(0.6 0.15 235);
  --tile-emerald: oklch(0.6 0.15 160);

  --grade-a: oklch(0.6 0.15 150);
  --grade-b: oklch(0.62 0.13 175);
  --grade-c: oklch(0.72 0.15 80);
  --grade-d: oklch(0.66 0.17 50);
  --grade-f: oklch(0.58 0.22 27);
  --sev-critical: var(--grade-f);
  --sev-high: oklch(0.64 0.19 40);
  --sev-medium: oklch(0.66 0.15 75);
  --sev-low: oklch(0.58 0.12 250);
  --sev-info: var(--muted-foreground);

  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --background: oklch(0.155 0.015 286);
    --foreground: oklch(0.975 0.005 286);
    --card: oklch(0.21 0.02 286 / 0.6);
    --card-solid: oklch(0.2 0.02 286);
    --card-foreground: oklch(0.975 0.005 286);
    --primary: oklch(0.72 0.17 292);
    --primary-foreground: oklch(0.17 0.04 287);
    --secondary: oklch(0.27 0.025 287);
    --secondary-foreground: oklch(0.975 0.005 286);
    --muted: oklch(0.26 0.02 287);
    --muted-foreground: oklch(0.72 0.02 286);
    --accent: oklch(0.28 0.03 287);
    --destructive: oklch(0.704 0.191 22.216);
    --border: oklch(1 0 0 / 11%);
    --input: oklch(1 0 0 / 16%);
    --ring: oklch(0.65 0.17 292);
    --aurora: 20%;
    --hue-violet: oklch(0.55 0.22 292);
    --hue-cyan: oklch(0.6 0.13 215);
    --hue-pink: oklch(0.55 0.2 345);
    --g1: oklch(0.78 0.15 292);
    --g2: oklch(0.78 0.15 345);
    --g3: oklch(0.82 0.12 210);
    --tile-violet: oklch(0.75 0.16 292);
    --tile-rose: oklch(0.75 0.16 15);
    --tile-amber: oklch(0.8 0.14 75);
    --tile-red: oklch(0.72 0.18 30);
    --tile-sky: oklch(0.77 0.12 230);
    --tile-emerald: oklch(0.76 0.14 160);
    --sev-low: oklch(0.72 0.11 250);
    --sev-medium: oklch(0.8 0.14 80);
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --background: oklch(0.155 0.015 286);
  --foreground: oklch(0.975 0.005 286);
  --card: oklch(0.21 0.02 286 / 0.6);
  --card-solid: oklch(0.2 0.02 286);
  --card-foreground: oklch(0.975 0.005 286);
  --primary: oklch(0.72 0.17 292);
  --primary-foreground: oklch(0.17 0.04 287);
  --secondary: oklch(0.27 0.025 287);
  --secondary-foreground: oklch(0.975 0.005 286);
  --muted: oklch(0.26 0.02 287);
  --muted-foreground: oklch(0.72 0.02 286);
  --accent: oklch(0.28 0.03 287);
  --destructive: oklch(0.704 0.191 22.216);
  --border: oklch(1 0 0 / 11%);
  --input: oklch(1 0 0 / 16%);
  --ring: oklch(0.65 0.17 292);
  --aurora: 20%;
  --hue-violet: oklch(0.55 0.22 292);
  --hue-cyan: oklch(0.6 0.13 215);
  --hue-pink: oklch(0.55 0.2 345);
  --g1: oklch(0.78 0.15 292);
  --g2: oklch(0.78 0.15 345);
  --g3: oklch(0.82 0.12 210);
  --tile-violet: oklch(0.75 0.16 292);
  --tile-rose: oklch(0.75 0.16 15);
  --tile-amber: oklch(0.8 0.14 75);
  --tile-red: oklch(0.72 0.18 30);
  --tile-sky: oklch(0.77 0.12 230);
  --tile-emerald: oklch(0.76 0.14 160);
  --sev-low: oklch(0.72 0.11 250);
  --sev-medium: oklch(0.8 0.14 80);
  color-scheme: dark;
}

*, *::before, *::after { box-sizing: border-box; border-color: var(--border); }
html { -webkit-text-size-adjust: 100%; background: var(--background); }
body {
  margin: 0;
  min-height: 100vh;
  color: var(--foreground);
  background:
    radial-gradient(60rem 38rem at 8% -12%, color-mix(in oklch, var(--hue-violet) var(--aurora), transparent), transparent 70%),
    radial-gradient(52rem 34rem at 96% -4%, color-mix(in oklch, var(--hue-cyan) var(--aurora), transparent), transparent 70%),
    radial-gradient(48rem 36rem at 55% 108%, color-mix(in oklch, var(--hue-pink) var(--aurora), transparent), transparent 70%),
    var(--background);
  background-attachment: fixed;
  font-family: "Inter", ui-sans-serif, system-ui, -apple-system, "Segoe UI", sans-serif;
  font-feature-settings: "cv11", "ss01";
  font-size: 15px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-underline-offset: 3px; }
img, svg { display: block; max-width: 100%; }
code, pre, kbd { font-family: ui-monospace, "SF Mono", "JetBrains Mono", Menlo, monospace; font-size: 0.85em; }
:not(pre) > code { background: var(--muted); padding: 0.15em 0.4em; border-radius: 0.3rem; }
pre {
  background: var(--muted); padding: 0.875rem 1rem; border-radius: calc(var(--radius) - 2px);
  overflow-x: auto; line-height: 1.5; margin: 0;
}
h1, h2, h3, h4 { line-height: 1.2; letter-spacing: -0.025em; margin: 0; font-weight: 600; }
h1 { font-size: clamp(2rem, 4vw + 1rem, 3.25rem); font-weight: 700; letter-spacing: -0.04em; }
h2 { font-size: 1.5rem; }
h3 { font-size: 1.125rem; }
p { margin: 0; }
:focus-visible { outline: 2px solid var(--ring); outline-offset: 2px; }

/* Layout */
.container { width: 100%; max-width: 1120px; margin: 0 auto; padding: 0 1rem; }
.container-narrow { max-width: 760px; }
.stack > * + * { margin-top: var(--gap, 1rem); }
.row { display: flex; gap: 0.75rem; align-items: center; flex-wrap: wrap; }
.between { justify-content: space-between; }
.grid { display: grid; gap: 1rem; }
.grid-2 { grid-template-columns: repeat(auto-fill, minmax(min(100%, 320px), 1fr)); }
.grid-3 { grid-template-columns: repeat(auto-fill, minmax(min(100%, 260px), 1fr)); }
.muted { color: var(--muted-foreground); }
.small { font-size: 0.8125rem; }
.mono { font-family: ui-monospace, "SF Mono", Menlo, monospace; }
.section { padding-block: 3.5rem; }
.section-sm { padding-block: 2rem; }
.lead { font-size: 1.125rem; color: var(--muted-foreground); }
.truncate { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); }

/* Header & footer */
.site-header {
  position: sticky; top: 0; z-index: 10; border-bottom: 1px solid var(--border);
  background: color-mix(in oklch, var(--background) 85%, transparent);
  backdrop-filter: blur(8px);
}
.site-header .container { display: flex; align-items: center; gap: 1.5rem; height: 3.5rem; }
.logo { display: flex; align-items: center; gap: 0.5rem; font-weight: 700; letter-spacing: -0.02em; text-decoration: none; }
.logo-mark {
  width: 1.5rem; height: 1.5rem; border-radius: 0.4rem; background: var(--primary); color: var(--primary-foreground);
  display: grid; place-items: center;
}
.nav { display: flex; gap: 0.25rem; margin-left: auto; }
.nav a { padding: 0.375rem 0.75rem; border-radius: calc(var(--radius) - 4px); text-decoration: none; color: var(--muted-foreground); font-size: 0.875rem; font-weight: 500; }
.nav a:hover, .nav a[aria-current="page"] { color: var(--foreground); background: var(--accent); }
@media (max-width: 640px) { .nav a.hide-sm { display: none; } }
.site-footer { border-top: 1px solid var(--border); padding: 2rem 0 3rem; margin-top: 3rem; font-size: 0.8125rem; color: var(--muted-foreground); }
.site-footer .container { display: flex; gap: 1.5rem; flex-wrap: wrap; justify-content: space-between; }
.site-footer nav { display: flex; gap: 1rem; flex-wrap: wrap; }
.site-footer a { text-decoration: none; }
.site-footer a:hover { color: var(--foreground); }

/* Button */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 0.5rem; white-space: nowrap;
  height: 2.25rem; padding: 0 1rem; border-radius: calc(var(--radius) - 2px); border: 1px solid transparent;
  font: inherit; font-size: 0.875rem; font-weight: 500; text-decoration: none; cursor: pointer;
  background: var(--primary); color: var(--primary-foreground); transition: background 0.15s, opacity 0.15s;
  box-shadow: 0 1px 2px rgb(0 0 0 / 0.05);
}
.btn:hover { opacity: 0.9; }
.btn-outline { background: var(--background); color: var(--foreground); border-color: var(--input); }
.btn-outline:hover, .btn-ghost:hover { background: var(--accent); opacity: 1; }
.btn-secondary { background: var(--secondary); color: var(--secondary-foreground); }
.btn-ghost { background: transparent; color: var(--foreground); box-shadow: none; }
.btn-sm { height: 2rem; padding: 0 0.75rem; font-size: 0.8125rem; }
.btn-lg { height: 2.5rem; padding: 0 1.5rem; }

/* Inputs */
.label { display: block; font-size: 0.875rem; font-weight: 500; margin-bottom: 0.375rem; }
.input, .textarea, .select {
  display: block; width: 100%; height: 2.25rem; padding: 0 0.75rem; font: inherit; font-size: 0.875rem;
  color: var(--foreground); background: transparent; border: 1px solid var(--input);
  border-radius: calc(var(--radius) - 2px); box-shadow: 0 1px 2px rgb(0 0 0 / 0.05);
}
.textarea { height: auto; min-height: 8rem; padding: 0.5rem 0.75rem; resize: vertical; font-family: ui-monospace, Menlo, monospace; font-size: 0.8125rem; }
.input:focus, .textarea:focus, .select:focus { outline: none; border-color: var(--ring); box-shadow: 0 0 0 3px color-mix(in oklch, var(--ring) 35%, transparent); }
.input::placeholder, .textarea::placeholder { color: var(--muted-foreground); }
.field + .field { margin-top: 1rem; }
.hint { font-size: 0.8125rem; color: var(--muted-foreground); margin-top: 0.375rem; }

/* Card */
.card {
  background: var(--card); color: var(--card-foreground); border: 1px solid var(--border);
  border-radius: var(--radius); box-shadow: 0 1px 2px rgb(0 0 0 / 0.04);
}
.card-header { padding: 1.25rem 1.25rem 0; display: grid; gap: 0.375rem; }
.card-title { font-weight: 600; letter-spacing: -0.015em; line-height: 1.3; }
.card-description { font-size: 0.875rem; color: var(--muted-foreground); }
.card-content { padding: 1.25rem; }
.card-footer { padding: 0 1.25rem 1.25rem; display: flex; gap: 0.5rem; align-items: center; }
a.card { text-decoration: none; transition: border-color 0.15s, background 0.15s; display: block; }
a.card:hover { border-color: var(--ring); }

/* Badge */
.badge {
  display: inline-flex; align-items: center; gap: 0.25rem; border-radius: calc(var(--radius) - 4px);
  padding: 0.125rem 0.5rem; font-size: 0.75rem; font-weight: 500; line-height: 1.4;
  border: 1px solid transparent; background: var(--primary); color: var(--primary-foreground); white-space: nowrap;
}
.badge-secondary { background: var(--secondary); color: var(--secondary-foreground); }
.badge-outline { background: transparent; color: var(--foreground); border-color: var(--border); }
.badge-dot::before { content: ""; width: 0.4rem; height: 0.4rem; border-radius: 50%; background: currentColor; }
.sev-critical { color: var(--sev-critical); }
.sev-high { color: var(--sev-high); }
.sev-medium { color: var(--sev-medium); }
.sev-low { color: var(--sev-low); }
.sev-info { color: var(--sev-info); }
.badge.sev { background: color-mix(in oklch, currentColor 12%, transparent); border-color: color-mix(in oklch, currentColor 25%, transparent); }

/* Grade */
.grade {
  display: inline-grid; place-items: center; width: 2.5rem; height: 2.5rem; border-radius: calc(var(--radius) - 2px);
  font-weight: 700; font-size: 1.125rem; color: #fff; flex-shrink: 0;
}
.grade-lg { width: 4.5rem; height: 4.5rem; font-size: 2.25rem; border-radius: var(--radius); }
.grade-sm { width: 1.75rem; height: 1.75rem; font-size: 0.875rem; }
.grade-A { background: var(--grade-a); }
.grade-B { background: var(--grade-b); }
.grade-C { background: var(--grade-c); }
.grade-D { background: var(--grade-d); }
.grade-F { background: var(--grade-f); }

/* Alert */
.alert { border: 1px solid var(--border); border-radius: var(--radius); padding: 0.875rem 1rem; display: grid; gap: 0.25rem; font-size: 0.875rem; }
.alert-title { font-weight: 600; }
.alert-destructive { color: var(--destructive); border-color: color-mix(in oklch, var(--destructive) 40%, transparent); }
.alert-destructive .muted { color: color-mix(in oklch, var(--destructive) 80%, var(--foreground)); }

/* Tabs (CSS-only, radio driven) */
.tabs > input { position: absolute; opacity: 0; pointer-events: none; }
.tabs-list {
  display: inline-flex; gap: 0.25rem; padding: 0.25rem; background: var(--muted); border-radius: var(--radius); margin-bottom: 0.75rem;
}
.tabs-list label {
  padding: 0.25rem 0.75rem; border-radius: calc(var(--radius) - 4px); font-size: 0.875rem; font-weight: 500;
  color: var(--muted-foreground); cursor: pointer;
}
.tabs-panel { display: none; }
#tab-url:checked ~ .tabs-list label[for="tab-url"],
#tab-paste:checked ~ .tabs-list label[for="tab-paste"] { background: var(--background); color: var(--foreground); box-shadow: 0 1px 2px rgb(0 0 0 / 0.08); }
#tab-url:checked ~ .panel-url, #tab-paste:checked ~ .panel-paste { display: block; }
#tab-url:focus-visible ~ .tabs-list label[for="tab-url"], #tab-paste:focus-visible ~ .tabs-list label[for="tab-paste"] { outline: 2px solid var(--ring); }

/* Table */
.table-wrap { width: 100%; overflow-x: auto; border: 1px solid var(--border); border-radius: var(--radius); }
table { width: 100%; border-collapse: collapse; font-size: 0.875rem; }
th { text-align: left; font-weight: 500; color: var(--muted-foreground); height: 2.5rem; padding: 0 0.75rem; border-bottom: 1px solid var(--border); white-space: nowrap; }
td { padding: 0.625rem 0.75rem; border-bottom: 1px solid var(--border); vertical-align: middle; }
tr:last-child td { border-bottom: 0; }
tbody tr:hover { background: color-mix(in oklch, var(--muted) 50%, transparent); }

/* Hero */
.hero { padding-block: 4.5rem 3rem; text-align: center; }
.hero .lead { max-width: 640px; margin: 1rem auto 0; }
.hero-form { max-width: 640px; margin: 2rem auto 0; text-align: left; }
.eyebrow { display: inline-flex; margin-bottom: 1.25rem; }
.input-group { display: flex; gap: 0.5rem; }
.input-group .input { flex: 1; height: 2.5rem; }
@media (max-width: 520px) { .input-group { flex-direction: column; } .input-group .input { flex: none; } }

/* Findings */
.finding { padding: 1rem 1.25rem; border-top: 1px solid var(--border); display: grid; gap: 0.375rem; }
.finding:first-child { border-top: 0; }
.finding pre { font-size: 0.75rem; margin-top: 0.25rem; white-space: pre-wrap; word-break: break-all; }
.score-meter { height: 0.5rem; border-radius: 999px; background: var(--muted); overflow: hidden; }
.score-meter > span { display: block; height: 100%; border-radius: inherit; }
.kv { display: grid; grid-template-columns: auto 1fr; gap: 0.375rem 1rem; font-size: 0.875rem; }
.kv dt { color: var(--muted-foreground); }
.kv dd { margin: 0; overflow-wrap: anywhere; }

/* Prose (learn articles) */
.prose { font-size: 1.0625rem; line-height: 1.75; }
.prose > * + * { margin-top: 1.25em; }
.prose h2 { font-size: 1.5rem; margin-top: 2.25em; }
.prose h3 { font-size: 1.2rem; margin-top: 1.75em; }
.prose ul, .prose ol { padding-left: 1.25rem; }
.prose li + li { margin-top: 0.4em; }
.prose blockquote { margin-left: 0; padding-left: 1rem; border-left: 2px solid var(--border); color: var(--muted-foreground); }
.prose a { text-decoration: underline; }

.separator { height: 1px; background: var(--border); border: 0; margin: 2rem 0; }
.check-list { list-style: none; padding: 0; margin: 0; display: grid; gap: 0.5rem; font-size: 0.875rem; }
.check-list li { display: flex; gap: 0.5rem; align-items: flex-start; }
.check-list li::before { content: "✓"; color: var(--grade-a); font-weight: 700; }
.clamp-2 { display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
@media (max-width: 640px) { .hide-sm-btn { display: none; } }
details > summary { list-style: none; }
details > summary::-webkit-details-marker { display: none; }
details > summary::after { content: "+"; float: right; color: var(--muted-foreground); }
details[open] > summary::after { content: "−"; }

/* Color & depth */
.card { -webkit-backdrop-filter: blur(14px); backdrop-filter: blur(14px); }
.text-gradient {
  background: linear-gradient(95deg, var(--g1), var(--g2) 55%, var(--g3));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.hero { position: relative; }
.hero::before {
  content: ""; position: absolute; inset: 1rem 15% auto; height: 18rem; z-index: -1; pointer-events: none;
  background: radial-gradient(closest-side, color-mix(in oklch, var(--hue-violet) 30%, transparent), transparent);
  filter: blur(20px);
}
.badge-brand {
  background: color-mix(in oklch, var(--primary) 12%, transparent); color: var(--primary);
  border-color: color-mix(in oklch, var(--primary) 30%, transparent);
}
.icon-tile {
  width: 2.25rem; height: 2.25rem; border-radius: calc(var(--radius) - 2px); display: grid; place-items: center;
  color: var(--tile, var(--primary)); background: color-mix(in oklch, var(--tile, var(--primary)) 14%, transparent);
  border: 1px solid color-mix(in oklch, var(--tile, var(--primary)) 25%, transparent); flex-shrink: 0;
}
.tile-violet { --tile: var(--tile-violet); }
.tile-rose { --tile: var(--tile-rose); }
.tile-amber { --tile: var(--tile-amber); }
.tile-red { --tile: var(--tile-red); }
.tile-sky { --tile: var(--tile-sky); }
.tile-emerald { --tile: var(--tile-emerald); }
.feature-card { transition: transform 0.15s, border-color 0.15s; }
.feature-card:hover { border-color: color-mix(in oklch, var(--tile, var(--primary)) 45%, var(--border)); }
.card-gradient {
  border: 0; color: #fff;
  background:
    radial-gradient(40rem 20rem at 100% 0%, oklch(0.7 0.16 210 / 0.55), transparent 60%),
    linear-gradient(130deg, oklch(0.48 0.23 287), oklch(0.53 0.24 320) 55%, oklch(0.62 0.21 352));
  box-shadow: 0 10px 40px -12px oklch(0.5 0.23 300 / 0.55);
}
.card-gradient .muted { color: rgb(255 255 255 / 0.85); }
.card-gradient .btn { background: #fff; color: oklch(0.32 0.12 287); }
a.card:hover { border-color: color-mix(in oklch, var(--primary) 45%, var(--border)); box-shadow: 0 6px 24px -10px color-mix(in oklch, var(--primary) 35%, transparent); }
.select { background: var(--card-solid); }

/* Theme toggle */
.theme-toggle { display: inline-flex; gap: 2px; padding: 2px; border: 1px solid var(--border); border-radius: 999px; background: var(--card); }
.theme-toggle a { display: grid; place-items: center; width: 1.75rem; height: 1.75rem; border-radius: 999px; color: var(--muted-foreground); }
.theme-toggle a:hover { color: var(--foreground); }
.theme-toggle a[aria-current="true"] { background: var(--accent); color: var(--primary); }
.site-header .nav { margin-left: auto; }
.header-actions { display: flex; align-items: center; gap: 0.75rem; }
@media (max-width: 640px) { .site-header .container { gap: 0.75rem; } .nav a { padding: 0.375rem 0.5rem; } }
@media (max-width: 420px) { .logo-text { display: none; } }