:root {
  --bg: #f5f5f2;
  --card: #ffffff;
  --ink: #1a1a1a;
  --muted: #666;
  --line: #ddd;
  --accent: #8f1f1f;
  --criteria: #7f7f7f;
  --cfr: #c00000;
  --emt: #e36c0a;
  --advanced: #bf9000;
  --cc: #00b050;
  --paramedic: #4472c4;
  --mc: #403152;
  --key: #31859c;
  --plain: #595959;
  --stop: #c00000;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #16181c;
    --card: #1f2228;
    --ink: #e8e8e4;
    --muted: #9a9a94;
    --line: #33363d;
  }
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font: 16px/1.45 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--ink);
}
a { color: var(--paramedic); }

/* ---------- header ---------- */
#topbar {
  position: sticky; top: 0; z-index: 30;
  display: flex; align-items: center; gap: .6rem;
  background: var(--accent); color: #fff;
  padding: .5rem .8rem;
  padding-top: max(.5rem, env(safe-area-inset-top));
}
#topbar .brand { display: flex; align-items: center; gap: .5rem; color: #fff; text-decoration: none; min-width: 0; }
#topbar .brand small { opacity: .75; font-weight: 400; }
#topbar .sol { width: 26px; height: 26px; flex: none; }
#topbar nav { margin-left: auto; display: flex; gap: .2rem; }
#topbar nav a {
  color: #fff; text-decoration: none; padding: .35rem .6rem; border-radius: 6px;
  font-size: .92rem; white-space: nowrap;
}
#topbar nav a.active { background: rgba(255,255,255,.22); }
.iconbtn {
  background: rgba(255,255,255,.15); color: #fff; border: 0; border-radius: 6px;
  font-size: 1.1rem; padding: .3rem .6rem; cursor: pointer;
}

#app { max-width: 860px; margin: 0 auto; padding: .8rem .8rem 3rem; }

/* ---------- home ---------- */
.searchwrap { position: sticky; top: 52px; z-index: 20; padding: .3rem 0 .5rem; background: var(--bg); }
#search {
  width: 100%; font-size: 1.05rem; padding: .6rem .9rem;
  border: 1.5px solid var(--line); border-radius: 10px;
  background: var(--card); color: var(--ink);
}
#search:focus { outline: 2px solid var(--paramedic); border-color: transparent; }
.sec { margin: 1.1rem 0 .4rem; }
.sec h2 {
  font-size: .85rem; letter-spacing: .06em; text-transform: uppercase;
  color: var(--muted); margin: 0 0 .4rem .2rem;
}
.plist { list-style: none; margin: 0; padding: 0; border: 1px solid var(--line); border-radius: 10px; overflow: hidden; }
.plist li { border-bottom: 1px solid var(--line); }
.plist li:last-child { border-bottom: 0; }
.plist a {
  display: block; padding: .6rem .8rem; text-decoration: none; color: var(--ink);
  background: var(--card);
}
.plist a:active { background: var(--line); }
.plist .pg { color: var(--muted); font-size: .8rem; float: right; margin-left: .5rem; }
.hit-snippet { display: block; color: var(--muted); font-size: .82rem; margin-top: .15rem; }
.noresults { color: var(--muted); text-align: center; padding: 2rem 0; }

/* ---------- protocol view ---------- */
.proto h1 { font-size: 1.35rem; margin: .4rem 0 .1rem; }
.proto .subtitle { color: var(--muted); font-style: italic; margin: 0 0 .8rem; }
.band { margin: 0 0 .8rem; border: 1px solid var(--line); border-radius: 8px; overflow: hidden; background: var(--card); }
.band > .bandhead {
  color: #fff; font-weight: 700; font-size: .82rem; letter-spacing: .05em;
  padding: .32rem .7rem; text-transform: uppercase;
}
.band-criteria > .bandhead { background: var(--criteria); }
.band-cfr > .bandhead { background: var(--cfr); }
.band-emt > .bandhead { background: var(--emt); }
.band-advanced > .bandhead { background: var(--advanced); }
.band-cc > .bandhead { background: var(--cc); }
.band-paramedic > .bandhead { background: var(--paramedic); }
.band-mc > .bandhead { background: var(--mc); }
.band-key > .bandhead { background: var(--key); }
.band-plain > .bandhead { background: var(--plain); }
.band .bandbody { padding: .55rem .8rem .6rem; }
.band ul { margin: .2rem 0; padding-left: 1.15rem; }
.band ul ul { margin: .1rem 0; }
.band li { margin: .18rem 0; }
.band p.para { margin: .35rem 0; }
.stopline {
  color: var(--stop); font-weight: 700; padding: .1rem .8rem .55rem;
  display: flex; align-items: center; gap: .45rem; font-size: .95rem;
}
.stopline::before { content: ""; width: .85em; height: .85em; border-radius: 50%; background: var(--stop); flex: none; }
sup { font-size: .72em; }
.psym {
  display: inline-flex; align-items: center; justify-content: center;
  width: 1.25em; height: 1.25em; border: 1.5px solid currentColor; border-radius: 50%;
  font-size: .7em; font-weight: 700; line-height: 1; vertical-align: 10%;
}
sup .psym { font-size: .95em; vertical-align: 0; }
.band table { border-collapse: collapse; margin: .5rem 0; font-size: .92rem; }
.band th, .band td { border: 1px solid var(--line); padding: .28rem .55rem; text-align: center; }
.band th { background: rgba(127,127,127,.12); }
.tablewrap { overflow-x: auto; }
.pnav { display: flex; justify-content: space-between; gap: .6rem; margin: 1.2rem 0; }
.pnav a {
  flex: 1; text-decoration: none; background: var(--card); border: 1px solid var(--line);
  border-radius: 8px; padding: .5rem .7rem; color: var(--ink); font-size: .88rem;
}
.pnav a small { display: block; color: var(--muted); }
.pnav a.next { text-align: right; }
.srcnote { color: var(--muted); font-size: .8rem; text-align: center; }

/* ---------- calculator ---------- */
.calcbar {
  position: sticky; top: 52px; z-index: 20;
  background: var(--card); border: 1px solid var(--line); border-radius: 12px;
  padding: .7rem .8rem; margin-bottom: .8rem;
  box-shadow: 0 2px 8px rgba(0,0,0,.08);
}
.calcrow { display: flex; flex-wrap: wrap; gap: .6rem; align-items: center; }
.calcrow label { font-size: .85rem; color: var(--muted); }
.wtinput { display: flex; align-items: center; gap: .35rem; }
#wt {
  width: 6.2rem; font-size: 1.3rem; font-weight: 700; padding: .35rem .55rem;
  border: 1.5px solid var(--line); border-radius: 8px; background: var(--bg); color: var(--ink);
}
#wt:focus { outline: 2px solid var(--paramedic); border-color: transparent; }
.seg { display: inline-flex; border: 1.5px solid var(--line); border-radius: 8px; overflow: hidden; }
.seg button {
  border: 0; background: transparent; color: var(--ink); padding: .42rem .7rem;
  font-size: .92rem; cursor: pointer;
}
.seg button.on { background: var(--paramedic); color: #fff; }
.wtconv { color: var(--muted); font-size: .9rem; }
.calcrow2 { margin-top: .55rem; display: flex; flex-wrap: wrap; gap: .6rem; align-items: center; }
#calcsearch {
  flex: 1; min-width: 9rem; padding: .45rem .7rem; font-size: .95rem;
  border: 1.5px solid var(--line); border-radius: 8px; background: var(--bg); color: var(--ink);
}
.ibwrow { margin-top: .55rem; display: flex; flex-wrap: wrap; gap: .6rem; align-items: center; font-size: .9rem; }
.ibwrow select {
  padding: .35rem .45rem; border: 1.5px solid var(--line); border-radius: 8px;
  background: var(--bg); color: var(--ink); font-size: .92rem;
}
.ibwout { color: var(--muted); }

.medcard {
  background: var(--card); border: 1px solid var(--line); border-radius: 10px;
  padding: .6rem .8rem; margin-bottom: .6rem;
}
.medcard .mhead { display: flex; align-items: baseline; gap: .5rem; flex-wrap: wrap; }
.medcard .mname { font-weight: 700; font-size: 1.02rem; }
.medcard .mdetail { color: var(--muted); font-size: .82rem; }
.medcard .chips { margin-left: auto; display: flex; gap: .3rem; }
.chip {
  font-size: .7rem; font-weight: 700; padding: .13rem .45rem; border-radius: 20px;
  color: #fff; letter-spacing: .03em; white-space: nowrap;
}
.chip-CFR { background: var(--cfr); }
.chip-EMT { background: var(--emt); }
.chip-ADVANCED { background: var(--advanced); }
.chip-CC { background: var(--cc); }
.chip-PARAMEDIC { background: var(--paramedic); }
.chip-MC { background: var(--mc); }
.chip-flag { background: transparent; color: var(--ink); border: 1px solid var(--line); }
.chip-pop { background: transparent; color: var(--muted); border: 1px solid var(--line); }
.medcard .mind { color: var(--muted); font-size: .88rem; margin: .1rem 0 .3rem; }
.medcard .mdose {
  font-size: 1.18rem; font-weight: 700; margin: .25rem 0;
  font-variant-numeric: tabular-nums;
}
.medcard .mdose .vol { color: var(--paramedic); font-weight: 600; font-size: 1rem; }
.medcard .capped { color: var(--cfr); font-size: .82rem; font-weight: 700; }
.medcard .mtext { font-size: .85rem; color: var(--muted); border-top: 1px dashed var(--line); margin-top: .35rem; padding-top: .35rem; }
.medcard .mnote { font-size: .8rem; color: var(--cfr); margin-top: .25rem; }
.medcard .mlinks { font-size: .8rem; margin-top: .3rem; }
.medcard .needwt { color: var(--muted); font-style: italic; }
.calcdisclaim {
  border: 1.5px solid var(--cfr); border-radius: 10px; background: var(--card);
  padding: .55rem .8rem; font-size: .85rem; margin-bottom: .8rem;
}

/* ---------- education layer ---------- */
.dlink {
  color: inherit; text-decoration: none;
  border-bottom: 1px dotted var(--paramedic);
}
.dlink:active { background: rgba(68,114,196,.15); }
.learnbox {
  background: var(--card); border: 1px solid var(--key); border-left: 4px solid var(--key);
  border-radius: 8px; padding: .5rem .7rem; margin: 0 0 .8rem; font-size: .9rem;
}
.learnbox a { color: var(--key); font-weight: 600; }
.learnhint { color: var(--muted); font-size: .82rem; }
.eyebrow {
  display: inline-block; font-size: .68rem; font-weight: 700; letter-spacing: .08em;
  text-transform: uppercase; color: #fff; background: var(--key);
  padding: .15rem .5rem; border-radius: 4px;
}
.edunote {
  border: 1px dashed var(--key); border-radius: 8px; padding: .45rem .7rem;
  font-size: .8rem; color: var(--muted); margin: .8rem 0;
}
.learnhead { display: flex; align-items: center; justify-content: space-between; gap: .6rem; margin: .4rem 0 .6rem; flex-wrap: wrap; }
.learnhead h1 { margin: 0; font-size: 1.35rem; }
.edu h1 { font-size: 1.4rem; margin: .2rem 0 .3rem; }
.edu h1 .brand, .fq .brand { color: var(--muted); font-weight: 400; font-size: .8em; }
.edu h2 {
  font-size: .82rem; letter-spacing: .06em; text-transform: uppercase;
  color: var(--key); margin: 1.1rem 0 .3rem; border-bottom: 1px solid var(--line); padding-bottom: .2rem;
}
.edu p { margin: .35rem 0; }
.edu ul { margin: .3rem 0; padding-left: 1.15rem; }
.edu li { margin: .2rem 0; }
.chip-class { background: var(--key); }
.kvrow { display: flex; gap: 1.2rem; flex-wrap: wrap; font-size: .92rem; margin: .5rem 0; color: var(--muted); }
.kvrow strong { color: var(--ink); }
.rationale dt { font-weight: 700; margin-top: .55rem; }
.rationale dd { margin: .15rem 0 0 1rem; color: var(--ink); }
.calcgo { font-weight: 600; }
.eduhits { display: flex; flex-wrap: wrap; gap: .4rem; }
.eduhits a {
  background: var(--card); border: 1px solid var(--key); border-radius: 20px;
  padding: .25rem .7rem; text-decoration: none; color: var(--ink); font-size: .88rem;
}

/* ---------- scope control & badges ---------- */
.ctrlrow { display: flex; align-items: center; gap: .5rem; flex-wrap: wrap; margin: 0 0 .7rem; }
.ctrllabel { font-size: .8rem; font-weight: 700; color: var(--muted); text-transform: uppercase; letter-spacing: .05em; }
.ctrlhint { font-size: .78rem; color: var(--muted); }
.scopeseg { flex-wrap: wrap; }
.scopeseg button { padding: .35rem .55rem; font-size: .85rem; }
.hidetoggle {
  background: var(--card); border: 1.5px solid var(--line); border-radius: 8px;
  color: var(--muted); font-size: .82rem; padding: .35rem .6rem; cursor: pointer; white-space: nowrap;
}
.hidetoggle.on { border-color: var(--key); color: var(--key); font-weight: 600; }
.scopebadge {
  display: inline-block; font-size: .62rem; font-weight: 700; letter-spacing: .03em;
  padding: .1rem .35rem; border-radius: 4px; margin-right: .4rem; vertical-align: 12%;
  background: var(--key); color: #fff; white-space: nowrap;
}
.scopebadge.over { background: transparent; color: var(--muted); border: 1px solid var(--line); }
.chip-scope { background: var(--key); }
.outscope > a { opacity: .5; }
.outscope > a:active { opacity: .75; }
.scopewarn {
  border: 1px solid var(--advanced); border-left: 4px solid var(--advanced);
  border-radius: 8px; background: var(--card); padding: .45rem .7rem;
  font-size: .85rem; margin: .1rem 0 .6rem;
}
.fscope { text-align: center; font-size: .72rem; font-weight: 700; color: var(--key); margin-top: .4rem; letter-spacing: .04em; }
.fscope.over { color: var(--muted); }
.qlevel {
  display: inline-block; font-size: .68rem; font-weight: 700; padding: .08rem .4rem;
  border-radius: 10px; background: rgba(49,133,156,.15); color: var(--key); margin-left: .3rem;
}

/* ---------- learn hub & study ---------- */
.learntiles { display: grid; grid-template-columns: repeat(auto-fit, minmax(140px, 1fr)); gap: .6rem; margin: .6rem 0 .9rem; }
.tile {
  background: var(--card); border: 1px solid var(--line); border-radius: 12px;
  padding: .8rem .7rem; text-align: center; text-decoration: none; color: var(--ink);
}
.tile:active { border-color: var(--paramedic); }
.tile .tico { display: block; font-size: 1.6rem; margin-bottom: .2rem; }
.tile small { display: block; color: var(--muted); margin-top: .15rem; }
.fcard {
  background: var(--card); border: 1px solid var(--line); border-radius: 14px;
  min-height: 11rem; padding: 1.1rem 1rem; margin: .8rem 0 .6rem;
  display: flex; flex-direction: column; justify-content: center;
  cursor: pointer; box-shadow: 0 2px 10px rgba(0,0,0,.08);
}
.fcard.isback { justify-content: flex-start; cursor: pointer; }
.fq { font-size: 1.35rem; font-weight: 700; text-align: center; }
.fhint { color: var(--muted); font-size: .78rem; text-align: center; margin-top: .8rem; }
.fctrl { display: flex; align-items: center; justify-content: center; gap: .7rem; margin: .6rem 0; color: var(--muted); }
.fbtn {
  background: var(--card); border: 1.5px solid var(--line); border-radius: 8px;
  color: var(--ink); font-size: 1rem; padding: .4rem .9rem; cursor: pointer;
}
.fbtn:active { border-color: var(--paramedic); }
.qprog { color: var(--muted); font-size: .85rem; margin: .5rem 0 .3rem; }
.qcard { background: var(--card); border: 1px solid var(--line); border-radius: 12px; padding: .8rem .9rem; }
.qtext { font-size: 1.02rem; margin: .2rem 0 .7rem; }
.qopts { display: grid; gap: .45rem; }
.qopt {
  text-align: left; background: var(--bg); border: 1.5px solid var(--line); border-radius: 8px;
  color: var(--ink); font-size: .98rem; padding: .55rem .7rem; cursor: pointer;
}
.qopt.correct { border-color: var(--cc); background: rgba(0,176,80,.12); font-weight: 700; }
.qopt.wrong { border-color: var(--cfr); background: rgba(192,0,0,.10); }
.qopt.dim { opacity: .55; }
.qexplain { border-top: 1px dashed var(--line); margin-top: .7rem; padding-top: .6rem; font-size: .92rem; }

/* ---------- about ---------- */
.about { background: var(--card); border: 1px solid var(--line); border-radius: 10px; padding: .9rem 1rem; }
.about h2 { font-size: 1.05rem; margin: 1rem 0 .3rem; }
.about h2:first-child { margin-top: 0; }
.legend dt { font-weight: 700; margin-top: .5rem; }
.legend dd { margin: 0 0 .2rem 1rem; color: var(--muted); }

#foot { max-width: 860px; margin: 0 auto; padding: 0 .9rem 1.5rem; color: var(--muted); font-size: .78rem; text-align: center; }

@media (max-width: 560px) {
  #topbar .brand span small { display: none; }
  #topbar nav a { padding: .35rem .45rem; font-size: .85rem; }
  .medcard .chips { margin-left: 0; }
}
@media print {
  #topbar, .searchwrap, .calcbar, .pnav { display: none; }
}