/* "Sectional" look from the iOS app: chart-paper background, terrain teal, airspace magenta. */
:root {
  --paper: #F4F1E8;
  --card: #FFFFFF;
  --card-alt: #EAE6DA;
  --ink: #17211E;
  --ink-soft: #5A6762;
  --teal: #1C6B5B;
  --teal-soft: #D6EAE3;
  --magenta: #A8306A;
  --magenta-soft: #F4DDE8;
  --blue: #2A64A8;
  --amber: #B86B00;
  --brown: #8A5A12;
  --indigo: #4F5B8C;
  --correct: #23804F;
  --correct-soft: #DDF1E4;
  --wrong: #C23B2B;
  --wrong-soft: #F8E0DB;
  --rule: #D9D3C3;
  --cond: "Avenir Next Condensed", "Roboto Condensed", "Arial Narrow", system-ui, sans-serif;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, system-ui, sans-serif;
  --mono: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}
@media (prefers-color-scheme: dark) {
  :root {
    --paper: #101715; --card: #1A2320; --card-alt: #22302B; --ink: #E7EEEA; --ink-soft: #9DB0A8;
    --teal: #45B096; --teal-soft: #183A32; --magenta: #E2689F; --magenta-soft: #3D1C2C;
    --blue: #6EA3E0; --amber: #F0A53A; --brown: #D9A35A; --indigo: #98A6DE;
    --correct: #4CC283; --correct-soft: #163826; --wrong: #F07A68; --wrong-soft: #41201B; --rule: #2C3A35;
  }
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0; background: var(--paper); color: var(--ink);
  font: 17px/1.45 var(--sans);
}
a { color: var(--teal); }
img { max-width: 100%; display: block; }
.wrap { max-width: 640px; margin: 0 auto; padding: 0 16px; }
.stack > * + * { margin-top: 16px; }
h1, h2, h3, .cond { font-family: var(--cond); letter-spacing: -0.01em; }
h1 { font-size: 34px; line-height: 1.08; font-weight: 800; margin: 0; }
h2 { font-size: 26px; line-height: 1.12; font-weight: 800; margin: 0; }
h3 { font-size: 19px; margin: 0; }
.soft { color: var(--ink-soft); }
.small { font-size: 14px; }
.tiny { font-size: 12.5px; }
.center { text-align: center; }
.label {
  font: 700 12.5px var(--cond); letter-spacing: 0.12em; text-transform: uppercase; color: var(--ink-soft);
  margin: 24px 0 8px;
}
.card {
  background: var(--card); border: 1px solid var(--rule); border-radius: 14px; padding: 16px;
}
.card.tight { padding: 12px; }

/* Buttons */
.btn {
  display: block; width: 100%; border: 0; border-radius: 12px; padding: 15px 18px; cursor: pointer;
  font: 700 18px var(--cond); text-align: center; text-decoration: none;
  background: var(--teal); color: #fff; -webkit-tap-highlight-color: transparent;
}
.btn:active { opacity: 0.85; }
.btn:disabled { opacity: 0.45; cursor: default; }
.btn.secondary { background: var(--teal-soft); color: var(--teal); font-weight: 600; }
.btn.ghost { background: transparent; color: var(--teal); font-weight: 600; padding: 10px; }
.btn.magenta { background: var(--magenta); }
.btn.inline { display: inline-block; width: auto; padding: 10px 16px; font-size: 16px; }

/* Top bar */
.topbar { display: flex; align-items: center; gap: 10px; padding: 12px 0; }
.topbar .brand { display: flex; align-items: center; gap: 8px; font: 800 19px var(--cond); color: var(--ink); text-decoration: none; }
.topbar .spacer { flex: 1; }
.topbar button.link, .linkbtn { background: none; border: 0; color: var(--teal); font: 600 16px var(--cond); cursor: pointer; padding: 8px 4px; }

/* Badge (Class-C rings around a drone) */
.badge { width: 112px; height: 112px; margin: 0 auto; }

/* Landing */
.hero { padding: 12px 0 8px; text-align: center; }
.hero h1 { font-size: 38px; margin-top: 14px; }
.hero p { color: var(--ink-soft); font-size: 18px; margin: 10px 0 0; }
.features { list-style: none; padding: 0; margin: 0; }
.features li { display: flex; gap: 12px; align-items: flex-start; }
.features li + li { margin-top: 14px; }
.features .ic { flex: 0 0 28px; color: var(--teal); padding-top: 2px; }
.features b { font: 700 17px var(--cond); display: block; }
.features span { color: var(--ink-soft); font-size: 15px; }
.disclaimer { font-size: 13px; color: var(--ink-soft); text-align: center; }

/* Areas list */
.area-row { display: flex; gap: 12px; align-items: center; }
.area-row + .area-row { margin-top: 12px; }
.dot { width: 12px; height: 12px; border-radius: 50%; flex: 0 0 12px; }
.area-row b { font: 700 17px var(--cond); display: block; }

/* Question card */
.qhead { display: flex; align-items: center; gap: 8px; justify-content: space-between; }
.tags { display: flex; gap: 6px; flex-wrap: wrap; }
.tag { font: 700 12px var(--cond); padding: 3px 8px; border-radius: 99px; text-transform: none; }
.tag.mono { font: 500 11px var(--mono); color: var(--ink-soft); background: var(--card-alt); }
.stem { font-size: 19px; font-weight: 600; line-height: 1.35; margin: 14px 0; }
.choice {
  display: flex; gap: 12px; align-items: flex-start; width: 100%; text-align: left;
  background: var(--card); border: 1px solid var(--rule); border-radius: 12px; padding: 14px;
  font: 17px/1.4 var(--sans); color: var(--ink); cursor: pointer; -webkit-tap-highlight-color: transparent;
}
.choice + .choice { margin-top: 10px; }
.choice .letter {
  flex: 0 0 28px; height: 28px; border-radius: 50%; display: grid; place-items: center;
  background: var(--card-alt); font: 800 15px var(--cond);
}
.choice .txt { flex: 1; }
.choice.sel { background: var(--teal-soft); border: 2px solid var(--teal); padding: 13px; }
.choice.sel .letter { background: var(--teal); color: #fff; }
.choice.right { background: var(--correct-soft); border: 2px solid var(--correct); padding: 13px; }
.choice.right .letter { background: var(--correct); color: #fff; }
.choice.wrong { background: var(--wrong-soft); border: 2px solid var(--wrong); padding: 13px; }
.choice.wrong .letter { background: var(--wrong); color: #fff; }
.choice:disabled { cursor: default; }
.explain { background: var(--card-alt); border-radius: 12px; padding: 14px; margin-top: 14px; }
.explain .verdict { font: 700 17px var(--cond); margin-bottom: 6px; }
.explain .verdict.ok { color: var(--correct); }
.explain .verdict.no { color: var(--wrong); }
.explain .src { font: 500 12px var(--mono); color: var(--ink-soft); margin-top: 8px; }

/* Figures */
.figure {
  position: relative; border: 1px solid var(--rule); border-radius: 12px; overflow: hidden;
  background: var(--card-alt); cursor: zoom-in; margin-top: 14px;
}
.figure img { width: 100%; max-height: 240px; object-fit: cover; object-position: center; }
.figure .cap {
  position: absolute; left: 8px; bottom: 8px; background: rgba(0,0,0,0.65); color: #fff;
  font: 600 13px var(--cond); padding: 4px 9px; border-radius: 99px;
}
.zoom {
  position: fixed; inset: 0; background: #0b0f0e; z-index: 50; display: flex; flex-direction: column;
}
.zoom .zbar { display: flex; align-items: center; gap: 8px; padding: 10px 12px; color: #fff; font: 600 16px var(--cond); }
.zoom .zbar .spacer { flex: 1; }
.zoom .zbar button { background: rgba(255,255,255,0.14); color: #fff; border: 0; border-radius: 10px; min-width: 44px; height: 40px; font: 700 18px var(--cond); cursor: pointer; padding: 0 12px; }
.zoom .pane { flex: 1; overflow: auto; -webkit-overflow-scrolling: touch; touch-action: pan-x pan-y pinch-zoom; }
.zoom .pane img { max-width: none; }

/* Progress dots */
.dots { display: flex; gap: 4px; }
.dots i { width: 8px; height: 8px; border-radius: 50%; background: var(--rule); display: block; }
.dots i.ok { background: var(--correct); }
.dots i.no { background: var(--wrong); }
.dots i.cur { outline: 1.5px solid var(--ink-soft); outline-offset: 1px; }

/* Readiness ring + bars */
.ringrow { display: flex; gap: 18px; align-items: center; }
.ring { flex: 0 0 118px; }
.ring text { font-family: var(--cond); }
.bar-row + .bar-row { margin-top: 16px; }
.bar-top { display: flex; align-items: center; gap: 10px; font: 600 16px var(--cond); }
.bar-top .pct { margin-left: auto; font-weight: 800; font-variant-numeric: tabular-nums; }
.bar { position: relative; height: 8px; border-radius: 99px; background: var(--card-alt); margin-top: 6px; }
.bar .fill { position: absolute; left: 0; top: 0; bottom: 0; border-radius: 99px; }
.bar .pass { position: absolute; left: 70%; top: -2px; width: 2px; height: 12px; background: var(--ink); opacity: 0.5; }

/* Paywall */
.price { font: 800 44px var(--cond); line-height: 1; }
.price small { font: 600 16px var(--cond); color: var(--ink-soft); }
.checks { list-style: none; padding: 0; margin: 0; }
.checks li { position: relative; padding-left: 28px; }
.checks li + li { margin-top: 10px; }
.checks li::before { content: "✓"; position: absolute; left: 2px; top: 0; color: var(--teal); font-weight: 800; }
.notice { background: var(--magenta-soft); color: var(--ink); border-radius: 12px; padding: 12px 14px; font-size: 15px; }

/* Sticky bottom action bar */
.actionbar {
  position: sticky; bottom: 0; background: linear-gradient(to bottom, transparent, var(--paper) 30%);
  padding: 18px 0 calc(12px + env(safe-area-inset-bottom));
}

/* Footer */
footer { padding: 28px 0 36px; font-size: 13px; color: var(--ink-soft); text-align: center; }
footer nav { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; margin-bottom: 8px; }
footer a { color: var(--ink-soft); }

/* Study app */
.statgrid { display: grid; grid-template-columns: repeat(3, 1fr); text-align: center; }
.statgrid div + div { border-left: 1px solid var(--rule); }
.statgrid b { display: block; font: 800 26px var(--cond); color: var(--teal); font-variant-numeric: tabular-nums; }
.statgrid span { font: 600 13px var(--cond); color: var(--ink-soft); }
.listbtn {
  display: flex; align-items: center; gap: 12px; width: 100%; text-align: left; cursor: pointer;
  background: var(--card); border: 1px solid var(--rule); border-radius: 14px; padding: 14px; color: var(--ink);
  font: 16px var(--sans);
}
.listbtn + .listbtn { margin-top: 10px; }
.listbtn b { font: 700 17px var(--cond); display: block; }
.listbtn .chev { margin-left: auto; color: var(--ink-soft); font-size: 20px; }
.examtop { display: flex; align-items: center; gap: 8px; padding: 10px 0; position: sticky; top: 0; background: var(--paper); z-index: 5; }
.timer { font: 600 16px var(--mono); font-variant-numeric: tabular-nums; margin: 0 auto; }
.timer.low { color: var(--wrong); }
.progress { height: 4px; background: var(--card-alt); border-radius: 99px; overflow: hidden; }
.progress > div { height: 100%; background: var(--magenta); }
.navrow { display: flex; gap: 10px; align-items: center; }
.navrow .btn.sq { width: 56px; flex: 0 0 56px; padding: 13px 0; }
.grid6 { display: grid; grid-template-columns: repeat(6, 1fr); gap: 8px; }
.grid6 button {
  min-height: 44px; border-radius: 8px; border: 2px solid transparent; background: var(--card-alt); color: var(--ink);
  font: 700 16px var(--cond); cursor: pointer; position: relative;
}
.grid6 button.ans { background: var(--teal-soft); }
.grid6 button.cur { border-color: var(--teal); }
.grid6 button.flag::after { content: "⚑"; position: absolute; top: 1px; right: 4px; font-size: 10px; color: var(--magenta); }
.seg { display: flex; background: var(--card-alt); border-radius: 10px; padding: 3px; }
.seg button { flex: 1; border: 0; background: transparent; padding: 8px; border-radius: 8px; font: 600 15px var(--cond); color: var(--ink); cursor: pointer; }
.seg button.on { background: var(--card); box-shadow: 0 1px 2px rgba(0,0,0,0.12); }
.review summary { list-style: none; display: flex; gap: 10px; cursor: pointer; font-size: 15px; }
.review summary::-webkit-details-marker { display: none; }
.review .mark { flex: 0 0 auto; font-weight: 800; }
.review + .review { margin-top: 10px; }
.modal {
  position: fixed; inset: 0; background: rgba(0,0,0,0.45); z-index: 40; display: flex; align-items: flex-end; justify-content: center;
}
.modal .sheet {
  background: var(--paper); width: 100%; max-width: 640px; max-height: 80vh; overflow: auto;
  border-radius: 16px 16px 0 0; padding: 16px 16px calc(16px + env(safe-area-inset-bottom));
}
.legal h2 { margin-top: 24px; font-size: 22px; }
.legal p, .legal li { color: var(--ink); }
.hidden { display: none !important; }
@media (min-width: 700px) {
  .hero h1 { font-size: 46px; }
}