:root {
  --ink: #1a1a2e;
  --muted: #5b5b72;
  --bg: #f7f7fb;
  --card: #ffffff;
  --line: #e6e6f0;
  --accent: #4f46e5;
  --pass: #15803d;
  --passbg: #dcfce7;
  --fail: #b91c1c;
  --failbg: #fee2e2;
}
* { box-sizing: border-box; }
body {
  margin: 0; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  color: var(--ink); background: var(--bg); line-height: 1.6;
}
.wrap { max-width: 880px; margin: 0 auto; padding: 0 20px; }
.site-header { background: var(--ink); color: #fff; padding: 28px 0 22px; }
.brand { font-size: 28px; font-weight: 800; letter-spacing: -0.5px; }
.tagline { margin: 4px 0 0; color: #c7c7d9; font-size: 15px; }
main .tool, main .pairs, main .guide, main .faq {
  background: var(--card); border: 1px solid var(--line); border-radius: 14px;
  padding: 26px; margin: 22px 0;
}
.colors { display: flex; gap: 14px; align-items: stretch; flex-wrap: wrap; }
.color-card { flex: 1 1 220px; }
.color-card label { display: block; font-weight: 700; margin-bottom: 8px; font-size: 14px; }
.picker-row { display: flex; gap: 10px; }
.picker-row input[type="color"] {
  width: 52px; height: 46px; border: 1px solid var(--line); border-radius: 8px;
  padding: 3px; background: #fff; cursor: pointer;
}
.picker-row input[type="text"] {
  flex: 1; font-size: 17px; font-family: ui-monospace, monospace; text-transform: uppercase;
  border: 1px solid var(--line); border-radius: 8px; padding: 0 12px;
}
.mid-actions { display: flex; flex-direction: column; gap: 8px; justify-content: center; }
.mid-actions button {
  font-size: 20px; border: 1px solid var(--line); background: #fff; border-radius: 8px;
  width: 46px; height: 46px; cursor: pointer;
}
.mid-actions button:hover { border-color: var(--accent); }
.result-grid { display: flex; gap: 18px; margin-top: 20px; flex-wrap: wrap; }
.ratio-box {
  min-width: 190px; text-align: center; border: 1px solid var(--line); border-radius: 12px;
  padding: 18px 12px; background: var(--bg);
}
.ratio-num { font-size: 44px; font-weight: 800; letter-spacing: -1px; }
.ratio-label { color: var(--muted); font-size: 13px; }
.grades { flex: 1 1 300px; display: grid; gap: 8px; }
.grade {
  display: flex; align-items: center; gap: 10px; border: 1px solid var(--line);
  border-radius: 10px; padding: 9px 14px; font-size: 14px;
}
.g-name { font-weight: 700; }
.g-need { color: var(--muted); margin-left: auto; font-family: ui-monospace, monospace; font-size: 13px; }
.g-badge {
  font-weight: 800; font-size: 12px; padding: 3px 10px; border-radius: 20px;
  background: #eee; color: var(--muted); min-width: 58px; text-align: center;
}
.g-badge.pass { background: var(--passbg); color: var(--pass); }
.g-badge.fail { background: var(--failbg); color: var(--fail); }
.preview {
  margin-top: 20px; border: 1px solid var(--line); border-radius: 12px; padding: 26px;
  transition: background 0.15s, color 0.15s;
}
.preview h2 { margin: 0 0 10px; font-size: 26px; }
.preview p { margin: 0 0 16px; }
.preview button {
  border: none; border-radius: 8px; padding: 10px 22px; font-size: 15px; font-weight: 700; cursor: pointer;
}
.actions { display: flex; gap: 10px; margin-top: 18px; flex-wrap: wrap; }
.actions button {
  border: 1px solid var(--line); background: #fff; border-radius: 8px;
  padding: 10px 18px; font-size: 14px; font-weight: 700; cursor: pointer;
}
.actions button.primary { background: var(--accent); border-color: var(--accent); color: #fff; }
.actions button:hover { filter: brightness(0.96); }
.hint { color: var(--muted); font-size: 13px; margin: 10px 0 0; }
.pairs h2, .guide h2, .faq h2 { margin-top: 0; font-size: 21px; letter-spacing: -0.3px; }
.pair-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); gap: 10px; }
.pair {
  border: 1px solid var(--line); border-radius: 10px; overflow: hidden; cursor: pointer; background: #fff;
}
.pair:hover { border-color: var(--accent); }
.pair .swatches { display: flex; height: 56px; }
.pair .swatches div { flex: 1; }
.pair .meta { padding: 8px 10px; font-size: 12px; font-family: ui-monospace, monospace; color: var(--muted); }
.pair .meta b { color: var(--pass); }
.guide table { border-collapse: collapse; width: 100%; margin: 12px 0; font-size: 15px; }
.guide th, .guide td { border: 1px solid var(--line); padding: 10px 14px; text-align: left; }
.guide th { background: var(--bg); }
.formula { font-family: ui-monospace, monospace; background: var(--bg); padding: 10px 14px; border-radius: 8px; display: inline-block; }
.note { color: var(--muted); font-size: 14px; }
.faq details { border: 1px solid var(--line); border-radius: 10px; padding: 12px 16px; margin-bottom: 10px; }
.faq summary { font-weight: 700; cursor: pointer; }
.site-footer { padding: 26px 0 40px; color: var(--muted); font-size: 13px; text-align: center; }
.footer-tools { margin-top: 8px; }
.footer-tools a { color: var(--accent); }
.brand-link { color: inherit; text-decoration: none; }
.site-nav { display: flex; gap: 8px; margin-top: 14px; flex-wrap: wrap; }
.site-nav a {
  color: #c7c7d9; text-decoration: none; font-size: 14px; font-weight: 600;
  padding: 6px 14px; border-radius: 20px; border: 1px solid #3a3a55;
}
.site-nav a.active, .site-nav a:hover { color: #fff; border-color: #6b63f0; background: rgba(79,70,229,.28); }

/* ---- Color blindness simulator page ---- */
.page-title { margin: 0 0 6px; font-size: 28px; letter-spacing: -0.5px; }
.page-intro { color: var(--muted); margin: 0 0 18px; }
.page-intro.small { font-size: 14px; }
.sub-h { font-size: 19px; margin: 30px 0 8px; letter-spacing: -0.3px; }
.sim-input { display: flex; gap: 14px; flex-wrap: wrap; margin-bottom: 20px; }
.sim-input .color-card { flex: 1 1 220px; }
.sev-card { flex: 1 1 220px; }
.sev-card label { display: block; font-weight: 700; margin-bottom: 8px; font-size: 14px; }
.sev-card label span { font-family: ui-monospace, monospace; color: var(--accent); }
.sev-card input[type="range"] { width: 100%; accent-color: var(--accent); }
.sev-hint { color: var(--muted); font-size: 12px; margin-top: 4px; }
.sim-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); gap: 10px; }
.sim-card { border: 1px solid var(--line); border-radius: 10px; overflow: hidden; background: #fff; }
.sim-swatch { height: 92px; display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 2px; transition: background .15s; }
.sim-aa { font-size: 26px; font-weight: 800; }
.sim-hex { font-family: ui-monospace, monospace; font-size: 12px; }
.sim-card .sim-name { font-weight: 700; font-size: 13px; padding: 8px 10px 0; }
.sim-tag { font-weight: 400; font-size: 11px; color: var(--muted); }
.sim-prev { font-size: 11px; color: var(--accent); padding: 0 10px; font-weight: 600; }
.sim-desc { font-size: 12px; color: var(--muted); padding: 2px 10px 10px; line-height: 1.45; }
.palette-table { border: 1px solid var(--line); border-radius: 10px; overflow-x: auto; }
.pt-row { display: grid; grid-template-columns: 92px repeat(5, minmax(108px, 1fr)); min-width: 660px; }
.pt-row + .pt-row { border-top: 1px solid var(--line); }
.pt-header { background: var(--bg); font-weight: 700; font-size: 12px; }
.pt-head { padding: 10px; font-size: 12px; }
.pt-name {
  padding: 10px; font-size: 13px; font-weight: 700; text-align: left;
  border: none; background: none; cursor: pointer; color: var(--ink);
}
button.pt-name:hover { color: var(--accent); text-decoration: underline; }
.pt-cell { display: flex; align-items: center; gap: 7px; padding: 8px 10px; font-size: 11px; }
.pt-dot { width: 26px; height: 26px; border-radius: 6px; border: 1px solid rgba(0,0,0,.12); flex: none; }
.pt-hex { font-family: ui-monospace, monospace; color: var(--muted); }
.vision-tabs { display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: 14px; }
.vision-tabs button {
  border: 1px solid var(--line); background: #fff; border-radius: 20px;
  padding: 8px 16px; font-size: 13px; font-weight: 700; cursor: pointer; color: var(--ink);
}
.vision-tabs button.on { background: var(--ink); color: #fff; border-color: var(--ink); }
.ui-preview { margin-top: 6px; }
.ui-card { border: 1px solid var(--line); border-radius: 12px; padding: 22px; transition: background .15s; }
.ui-head { font-size: 20px; font-weight: 800; margin: 0 0 6px; }
.ui-body { font-size: 14px; margin: 0 0 12px; }
.ui-badges { display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: 14px; }
.ui-badge { font-size: 12px; font-weight: 700; padding: 5px 12px; border-radius: 16px; }
.ui-btn { border: none; border-radius: 8px; padding: 10px 22px; font-size: 14px; font-weight: 700; cursor: pointer; margin-bottom: 18px; }
.ui-bars { display: flex; gap: 8px; align-items: flex-end; height: 90px; margin-bottom: 4px; }
.ui-bar { flex: 1; border-radius: 5px 5px 0 0; }
.ui-bar:nth-child(1) { height: 55%; } .ui-bar:nth-child(2) { height: 80%; }
.ui-bar:nth-child(3) { height: 40%; } .ui-bar:nth-child(4) { height: 95%; }
.ui-bar:nth-child(5) { height: 65%; }
.ui-bar-labels { display: flex; gap: 8px; }
.ui-bar-labels span { flex: 1; text-align: center; font-size: 11px; color: var(--muted); font-weight: 700; }
@media (max-width: 560px) {
  .mid-actions { flex-direction: row; }
  .ratio-num { font-size: 36px; }
}

/* Palette generator */
.pg-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(160px, 1fr)); gap: 12px; margin: 12px 0 26px; }
.pg-swatch { border: 1px solid var(--line); border-radius: 10px; overflow: hidden; background: #fff; }
.pg-color { height: 76px; }
.pg-info { padding: 9px 11px; font-size: 12px; }
.pg-name { font-weight: 700; margin-bottom: 3px; }
.pg-hex { font-family: ui-monospace, monospace; font-weight: 700; cursor: pointer; color: var(--accent, #1a56db); margin-bottom: 6px; }
.pg-hex:hover { text-decoration: underline; }
.pg-ratio { color: var(--muted); margin-top: 4px; line-height: 1.7; }
.pg-ratio strong { color: var(--ink); }
.pg-badge { display: inline-block; font-size: 10px; font-weight: 700; padding: 2px 8px; border-radius: 12px; margin-left: 4px; }
.pg-aaa { background: #e6f4ea; color: #137333; }
.pg-aa { background: #d9edf9; color: #0b5fa5; }
.pg-la { background: #fef7e0; color: #8a6d00; }
.pg-no { background: #fce8e6; color: #a50e0e; }
input.invalid { border-color: #a50e0e !important; background: #fce8e6; }