/* ── Design tokens ─────────────────────────────────────────── */

:root {
  /* CWV rating colours — matches Chrome DevTools / Lighthouse */
  --good:      #0cce6b;
  --warn:      #ffa400;
  --poor:      #ff4e42;

  /* Surface */
  --bg:        #f4f3f1;
  --surface:   #ffffff;
  --border:    #e2ddd6;
  --text:      #1c1b18;
  --muted:     #6b6760;

  /* Code block */
  --code-bg:   #1e1e2e;
  --code-text: #cdd6f4;

  /* Header */
  --header-bg: #12122a;

  --radius: 10px;
  --shadow: 0 1px 2px rgba(0,0,0,.06), 0 4px 14px rgba(0,0,0,.08);
  --font:   system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;
  --mono:   "Consolas","SF Mono","Fira Code","Courier New",monospace;
}

/* ── Reset ─────────────────────────────────────────────────── */

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  font-size: 1rem;
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

main { flex: 1; }

/* ── Layout ────────────────────────────────────────────────── */

.container {
  max-width: 1240px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* ── Site header ───────────────────────────────────────────── */

.site-header {
  background: var(--header-bg);
  color: #fff;
  padding: 1.1rem 0;
  border-bottom: 3px solid var(--warn);
}

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}

.site-header__title {
  font-size: 1.375rem;
  font-weight: 700;
  letter-spacing: -.025em;
}

.site-header__sub {
  font-size: .8125rem;
  color: rgba(255,255,255,.55);
  margin-top: .15rem;
}

.site-header__ref {
  color: var(--warn);
  text-decoration: none;
  font-size: .8125rem;
  font-weight: 500;
  white-space: nowrap;
}
.site-header__ref:hover { text-decoration: underline; }

/* ── Card grid ─────────────────────────────────────────────── */

.card-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.125rem;
  padding: 1.375rem 0;
}

@media (max-width: 1080px) {
  .card-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 560px) {
  .card-grid { grid-template-columns: 1fr; }
}

/* ── Card ──────────────────────────────────────────────────── */

.card {
  background: var(--surface);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 1.125rem;
  display: flex;
  flex-direction: column;
  gap: .8rem;
  border-top: 3px solid transparent;
}

.card__header {
  display: flex;
  gap: .75rem;
  align-items: flex-start;
}

.card__abbr {
  font-family: var(--mono);
  font-size: 1.625rem;
  font-weight: 700;
  line-height: 1;
  color: var(--header-bg);
  flex-shrink: 0;
  padding-top: .1rem;
}

.card__name {
  font-size: .9375rem;
  font-weight: 600;
  line-height: 1.3;
}

.card__desc {
  font-size: .78125rem;
  color: var(--muted);
  margin-top: .25rem;
  line-height: 1.45;
}

/* ── Threshold bar ─────────────────────────────────────────── */

.threshold-bar__track {
  display: flex;
  border-radius: 5px;
  overflow: hidden;
  height: 26px;
}

.tb-good,
.tb-warn,
.tb-poor {
  width: var(--w);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: .625rem;
  font-weight: 700;
  color: #fff;
  letter-spacing: .01em;
  white-space: nowrap;
  overflow: hidden;
  text-shadow: 0 1px 2px rgba(0,0,0,.25);
}

.tb-good { background: var(--good); }
.tb-warn { background: var(--warn); }
.tb-poor { background: var(--poor); }

.threshold-bar__legend {
  display: flex;
  justify-content: space-between;
  margin-top: .3rem;
  font-size: .625rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: .04em;
}

.leg--good { color: var(--good); }
.leg--warn { color: var(--warn); }
.leg--poor { color: var(--poor); }

/* ── Accordion ─────────────────────────────────────────────── */

.accordion {
  border-top: 1px solid var(--border);
  padding-top: .7rem;
}

.accordion > summary {
  cursor: pointer;
  font-size: .78125rem;
  font-weight: 600;
  color: var(--muted);
  list-style: none;
  display: flex;
  align-items: center;
  gap: .375rem;
  user-select: none;
}
.accordion > summary::-webkit-details-marker { display: none; }
.accordion > summary::before {
  content: '▶';
  font-size: .5rem;
  transition: transform .15s ease;
  flex-shrink: 0;
}
.accordion[open] > summary::before { transform: rotate(90deg); }

.accordion ul {
  margin-top: .6rem;
  padding-left: 1.1rem;
  display: flex;
  flex-direction: column;
  gap: .3rem;
  font-size: .78125rem;
  line-height: 1.45;
}

.accordion ul code {
  font-family: var(--mono);
  font-size: .6875rem;
  background: #f0ece5;
  padding: .05em .3em;
  border-radius: 3px;
}

/* ── Snippet ───────────────────────────────────────────────── */

.snippet {
  position: relative;
  border-radius: 6px;
  overflow: hidden;
  margin-top: .6rem;
}

.snippet pre {
  background: var(--code-bg);
  color: var(--code-text);
  font-family: var(--mono);
  font-size: .6875rem;
  line-height: 1.65;
  padding: .875rem 1rem;
  overflow-x: auto;
  margin: 0;
  tab-size: 2;
}

.snippet__copy {
  position: absolute;
  top: .45rem;
  right: .45rem;
  background: rgba(255,255,255,.1);
  color: rgba(255,255,255,.7);
  border: 1px solid rgba(255,255,255,.18);
  border-radius: 4px;
  font-size: .625rem;
  font-family: var(--font);
  font-weight: 600;
  padding: .2rem .5rem;
  cursor: pointer;
  transition: background .15s, color .15s, border-color .15s;
  letter-spacing: .03em;
}
.snippet__copy:hover {
  background: rgba(255,255,255,.2);
  color: #fff;
}
.snippet__copy.copied {
  background: rgba(12,206,107,.2);
  color: #0cce6b;
  border-color: rgba(12,206,107,.35);
}

/* ── Footer ────────────────────────────────────────────────── */

.site-footer {
  border-top: 1px solid var(--border);
  padding: 1rem 0;
  margin-top: .25rem;
}

.site-footer p {
  font-size: .75rem;
  color: var(--muted);
  text-align: center;
}

.site-footer a {
  color: var(--muted);
  text-decoration: underline;
}
.site-footer a:hover { color: var(--text); }

/* ── Dark mode ─────────────────────────────────────────────── */

@media (prefers-color-scheme: dark) {
  :root {
    --bg:        #0f0f18;
    --surface:   #1a1a2e;
    --border:    #2c2c44;
    --text:      #e8e6e2;
    --muted:     #9896a4;
    --code-bg:   #0c0c18;
    --header-bg: #0c0c18;
  }

  .card__abbr { color: #e8e6e2; }
  .accordion ul code { background: #2a2a40; color: #cdd6f4; }
}