/* Layout: a control rail beside a numbered, multi-column ledger of sites; the rail stacks above the list on phones.
   Tier color is one cobalt hue whose strength tracks Chrome's rank band: solid for the most visited, fading through 1K, 5K and 10K. */
:root {
  --bg: #edf0f5;
  --surface: #ffffff;
  --ink: #0f1a2c;
  --muted: #5a6579;
  --line: #d5dbe5;
  --accent: #2343c8;
  --accent-ink: #ffffff;
  --tier-1k: #c9d3f6;
  --tier-5k: #dfe5fa;
  --tier-10k: transparent;
  --tier-text: #1b2f86;
  --adult: #a8321f;
  --focus: #e08a00;

  --display: "Bricolage Grotesque", "Avenir Next", "Segoe UI", system-ui, sans-serif;
  --body: "IBM Plex Sans", "Segoe UI", system-ui, -apple-system, sans-serif;
  --mono: "IBM Plex Mono", ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;

  --step--1: 0.8125rem;
  --step-0: 0.9375rem;
  --step-1: 1.125rem;
  --step-2: 1.5rem;
  --step-3: clamp(2rem, 1.4rem + 2.6vw, 3.25rem);
  --radius: 10px;
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0c121b;
    --surface: #141c28;
    --ink: #e6ebf4;
    --muted: #96a1b5;
    --line: #273245;
    --accent: #7f97ff;
    --accent-ink: #0b1430;
    --tier-1k: #2c3b72;
    --tier-5k: #1f2a50;
    --tier-10k: transparent;
    --tier-text: #c9d4ff;
    --adult: #ff8f7a;
    --focus: #ffb547;
    color-scheme: dark;
  }
}

:root[data-theme="dark"] {
  --bg: #0c121b;
  --surface: #141c28;
  --ink: #e6ebf4;
  --muted: #96a1b5;
  --line: #273245;
  --accent: #7f97ff;
  --accent-ink: #0b1430;
  --tier-1k: #2c3b72;
  --tier-5k: #1f2a50;
  --tier-10k: transparent;
  --tier-text: #c9d4ff;
  --adult: #ff8f7a;
  --focus: #ffb547;
  color-scheme: dark;
}

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

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

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--body);
  font-size: var(--step-0);
  line-height: 1.5;
}

a { color: var(--accent); text-underline-offset: 0.15em; }

:focus-visible { outline: 2px solid var(--focus); outline-offset: 2px; }

.page {
  max-width: 88rem;
  margin: 0 auto;
  padding-block: 2.5rem 3rem;
  padding-left: max(16px, env(safe-area-inset-left, 0px));
  padding-right: max(16px, env(safe-area-inset-right, 0px));
  display: grid;
  gap: 2rem;
}

/* Masthead */
.masthead { display: grid; gap: 0.5rem; max-width: 46rem; }
.masthead h1 {
  margin: 0;
  font-family: var(--display);
  font-weight: 700;
  font-size: var(--step-3);
  line-height: 1.02;
  letter-spacing: -0.02em;
  text-wrap: balance;
}
.lede { margin: 0; color: var(--muted); font-size: var(--step-1); max-width: 40rem; }
.lede strong { color: var(--ink); font-weight: 600; font-variant-numeric: tabular-nums; }

.layout {
  display: grid;
  grid-template-columns: minmax(17rem, 20rem) minmax(0, 1fr);
  gap: 2rem;
  align-items: start;
}

/* Controls */
.controls {
  position: sticky;
  top: calc(env(safe-area-inset-top, 0px) + 1.25rem);
  display: grid;
  gap: 1.25rem;
  padding: 1.25rem;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}
.group { margin: 0; padding: 0; border: 0; display: grid; gap: 0.6rem; min-width: 0; }
.group legend, .seg-label {
  padding: 0;
  font-size: var(--step--1);
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
}
.group legend { margin-bottom: 0.6rem; }

.countries { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 0.5rem; }
.country {
  position: relative;
  display: grid;
  gap: 0.1rem;
  padding: 0.6rem 0.75rem;
  border: 1px solid var(--line);
  border-radius: 8px;
  cursor: pointer;
  transition: border-color 120ms, background-color 120ms;
}
.country input, .seg input { position: absolute; opacity: 0; pointer-events: none; }
.country .cc { font-family: var(--display); font-weight: 700; font-size: var(--step-2); line-height: 1; }
.country .cname { font-size: var(--step--1); color: var(--muted); }
.country:hover { border-color: var(--accent); }
.country:has(input:checked) { background: var(--accent); border-color: var(--accent); color: var(--accent-ink); }
.country:has(input:checked) .cname { color: inherit; opacity: 0.85; }
.country:has(input:focus-visible), .seg label:has(input:focus-visible) { outline: 2px solid var(--focus); outline-offset: 2px; }

.mix { display: grid; grid-template-columns: minmax(0, 1fr) auto minmax(0, 1fr); align-items: end; gap: 0.5rem; }
.num { display: grid; gap: 0.3rem; font-size: var(--step--1); color: var(--muted); }
.num input {
  width: 100%;
  padding: 0.5rem 0.6rem;
  font: 500 var(--step-1) var(--mono);
  font-variant-numeric: tabular-nums;
  color: var(--ink);
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: 6px;
}
.op { padding-bottom: 0.55rem; color: var(--muted); font-family: var(--mono); }
.total { margin: 0; font-size: var(--step--1); color: var(--muted); }
.total span { font-family: var(--mono); color: var(--ink); font-weight: 500; }

.check { display: flex; gap: 0.55rem; align-items: center; cursor: pointer; }
.check input { width: 1.05rem; height: 1.05rem; accent-color: var(--accent); margin: 0; }

.seg { display: flex; flex-wrap: wrap; align-items: center; gap: 0.35rem; }
.seg-label { flex-basis: 100%; }
.seg label {
  position: relative;
  padding: 0.35rem 0.7rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  font-size: var(--step--1);
  cursor: pointer;
}
.seg label:has(input:checked) { border-color: var(--accent); color: var(--accent); font-weight: 600; }

button { font: inherit; cursor: pointer; }
.primary {
  padding: 0.8rem 1rem;
  font-family: var(--display);
  font-weight: 700;
  font-size: var(--step-1);
  color: var(--accent-ink);
  background: var(--accent);
  border: 0;
  border-radius: 8px;
  transition: transform 80ms ease;
}
.primary:active { transform: translateY(1px); }
.exports { display: flex; flex-wrap: wrap; gap: 0.5rem; }
.ghost {
  padding: 0.45rem 0.8rem;
  font-size: var(--step--1);
  font-weight: 500;
  color: var(--ink);
  background: transparent;
  border: 1px solid var(--line);
  border-radius: 6px;
}
.ghost:hover { border-color: var(--accent); color: var(--accent); }
.toast { margin: 0; min-height: 1.25rem; font-size: var(--step--1); color: var(--muted); }
.fallback { display: grid; gap: 0.5rem; font-size: var(--step--1); }
.fallback p { margin: 0; }
.fallback textarea {
  width: 100%;
  font: var(--step--1) var(--mono);
  color: var(--ink);
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: 6px;
}

/* Results */
.results { display: grid; gap: 1.25rem; min-width: 0; }
.summary { display: grid; gap: 0.75rem; }
.summary-head { display: flex; flex-wrap: wrap; align-items: baseline; justify-content: space-between; gap: 0.25rem 1rem; }
.summary h2 { margin: 0; font-family: var(--display); font-weight: 700; font-size: var(--step-2); line-height: 1.15; text-wrap: balance; }
.summary-meta { margin: 0; font-size: var(--step--1); color: var(--muted); }

.bar {
  display: flex;
  height: 0.6rem;
  border-radius: 999px;
  overflow: hidden;
  background: var(--line);
}
.bar span { display: block; height: 100%; }
.bar span + span { box-shadow: inset 2px 0 0 var(--bg); }

.legend { list-style: none; margin: 0; padding: 0; display: flex; flex-wrap: wrap; gap: 0.4rem 1.1rem; font-size: var(--step--1); color: var(--muted); }
.legend li { display: inline-flex; align-items: center; gap: 0.4rem; }
.legend b { color: var(--ink); font-weight: 600; font-family: var(--mono); font-variant-numeric: tabular-nums; }

.tier-top { background: var(--accent); color: var(--accent-ink); border-color: var(--accent); }
.tier-1k { background: var(--tier-1k); color: var(--tier-text); border-color: var(--tier-1k); }
.tier-5k { background: var(--tier-5k); color: var(--tier-text); border-color: var(--tier-5k); }
.tier-10k { background: var(--tier-10k); color: var(--tier-text); border-color: var(--tier-text); }
.bar .tier-10k { background: var(--surface); }

.sites {
  list-style: none;
  margin: 0;
  padding: 0.5rem 0;
  columns: 17rem auto;
  column-gap: 1.5rem;
  column-rule: 1px solid var(--line);
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}
.sites li {
  break-inside: avoid;
  display: grid;
  grid-template-columns: 2.4rem minmax(0, 1fr) auto;
  align-items: center;
  gap: 0.5rem;
  padding: 0.28rem 0.9rem;
}
.sites .n { font: var(--step--1) var(--mono); color: var(--muted); text-align: right; font-variant-numeric: tabular-nums; }
.sites a {
  font-family: var(--mono);
  font-size: var(--step--1);
  color: var(--ink);
  text-decoration: none;
  overflow-wrap: anywhere;
}
.sites a:hover { color: var(--accent); text-decoration: underline; }
.chip {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  padding: 0.05rem 0.45rem;
  font: 500 0.6875rem/1.5 var(--mono);
  letter-spacing: 0.02em;
  border: 1px solid transparent;
  border-radius: 4px;
  white-space: nowrap;
}
.chip .adult { color: var(--adult); font-weight: 600; }
.tier-top .adult { color: inherit; }
.legend .chip { min-width: 2.6rem; justify-content: center; }

.error { margin: 0; padding: 1rem; color: var(--adult); background: var(--surface); border: 1px solid var(--adult); border-radius: var(--radius); }

/* Notes */
.notes { max-width: 46rem; display: grid; gap: 0.5rem; color: var(--muted); font-size: var(--step--1); }
.notes h2 { margin: 0; font-family: var(--display); font-weight: 700; font-size: var(--step-1); color: var(--ink); }
.notes p { margin: 0; }

@media (max-width: 52rem) {
  .layout { grid-template-columns: minmax(0, 1fr); }
  .controls { position: static; }
  .countries { grid-template-columns: repeat(4, minmax(0, 1fr)); }
  .country .cname { display: none; }
  .country { justify-items: center; }
}

@media (max-width: 26rem) {
  .page { padding-block: 1.5rem 2rem; }
  .sites li { padding-inline: 0.6rem; grid-template-columns: 2rem minmax(0, 1fr) auto; }
}

@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; animation: none !important; }
}

.sites.fresh li { animation: settle 260ms ease-out both; }
@keyframes settle { from { opacity: 0.35; transform: translateY(2px); } to { opacity: 1; transform: none; } }