@import url('https://fonts.googleapis.com/css2?family=DM+Serif+Display:ital@0;1&family=Outfit:wght@400;500;600;700&display=swap');

:root {
  --navy: #10283b;
  --navy-2: #16364d;
  --ink: #1c2a33;
  --muted: #5b6b75;
  --paper: #f4efe4;
  --paper-2: #fbf7ef;
  --line: #d9d0c0;
  --mint: #60e4cb;
  --mint-deep: #1aa88f;
  --gold: #c9a227;
  --danger: #b42318;
  --ok: #1f7a4d;
  --shadow: 0 18px 40px rgba(16, 40, 59, .12);
  --side: 280px;
  --radius: 18px;
  font-family: Outfit, "Segoe UI", sans-serif;
  font-size: 17px;
  color: var(--ink);
  background: var(--paper);
}

* { box-sizing: border-box; }
html, body { margin: 0; min-height: 100%; background: var(--paper); }
body { display: flex; }
a { color: inherit; }
button, select, input { font: inherit; }
img { max-width: 100%; }
h1, h2, h3, .brand { font-family: "DM Serif Display", Georgia, serif; font-weight: 400; letter-spacing: -.02em; }
h1 { font-size: clamp(2.3rem, 4.4vw, 3.8rem); line-height: 1.08; margin: .15rem 0 .5rem; }
h2 { font-size: 1.7rem; margin: 0 0 .45rem; }
h3 { font-size: 1.28rem; margin: 0 0 .4rem; }
p { line-height: 1.65; color: #33444d; }
.sr-only, .skip-link:not(:focus) { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); }
.skip-link:focus { position: fixed; z-index: 50; left: 1rem; top: 1rem; background: #fff; padding: .6rem 1rem; }

#app { display: flex; min-height: 100vh; width: 100%; }
.sidebar {
  width: var(--side); flex: none; background: linear-gradient(180deg, var(--navy) 0%, #0b1c2a 100%);
  color: #e8f3f1; padding: 1.15rem .9rem 1.4rem; display: flex; flex-direction: column; gap: .9rem;
  position: sticky; top: 0; height: 100vh; overflow: auto;
}
.sidebar.collapsed { display: none; }
.brand { display: flex; gap: .7rem; align-items: center; text-decoration: none; color: #fff; font-size: 1.45rem; }
.brand-mark { width: 42px; height: 42px; color: var(--mint); flex: none; }
.brand-sub { display: block; font-family: Outfit, sans-serif; font-size: .62rem; letter-spacing: .16em; color: #9eb0bb; margin-top: .15rem; }
.side-course { background: rgba(255,255,255,.06); border: 1px solid rgba(255,255,255,.08); border-radius: 14px; padding: .85rem; }
.course-label { display: block; font-weight: 600; margin: .2rem 0 .7rem; }
.progress { height: 7px; background: rgba(255,255,255,.12); border-radius: 99px; overflow: hidden; }
.progress span { display: block; height: 100%; background: var(--mint); }
.sidebar .small { color: #9eb0bb; }
nav { display: flex; flex-direction: column; gap: .2rem; }
.nav-link {
  display: flex; align-items: center; gap: .65rem; color: #d5e2e8; text-decoration: none;
  padding: .62rem .7rem; border-radius: 12px;
}
.nav-link:hover, .nav-link.active { background: rgba(96,228,203,.14); color: #fff; }
.nav-count { margin-left: auto; background: rgba(96,228,203,.18); color: var(--mint); border-radius: 99px; padding: .05rem .45rem; font-size: .72rem; }
.side-bottom { margin-top: auto; font-size: .82rem; color: #8ea0ab; }
.source-badge { display: flex; gap: .6rem; align-items: flex-start; background: rgba(96,228,203,.1); border-radius: 12px; padding: .7rem; margin-bottom: .7rem; color: #dff8f2; }
.source-badge span { display: block; color: #9eb0bb; font-size: .72rem; }
.sidebar-backdrop { display: none; }
.workspace { flex: 1; min-width: 0; }
.workspace.wide { }
.topbar {
  display: flex; justify-content: space-between; align-items: center; gap: 1rem;
  padding: .85rem 1.5rem; border-bottom: 1px solid var(--line); background: rgba(251,247,239,.9); position: sticky; top: 0; z-index: 5;
}
.top-left, .top-right { display: flex; align-items: center; gap: .7rem; }
.breadcrumb { font-size: .78rem; letter-spacing: .12em; color: var(--muted); }
.breadcrumb span { opacity: .5; padding: 0 .35rem; }
.review-date { font-size: .72rem; letter-spacing: .12em; color: var(--muted); }
.main { padding: 2rem 2.5rem 4rem; width: 100%; max-width: none; }
.site-footer { display: flex; justify-content: space-between; gap: 1rem; padding: 1.2rem 2.5rem 1.8rem; color: var(--muted); font-size: .9rem; border-top: 1px solid var(--line); }
.page-heading { display: flex; justify-content: space-between; gap: 1.4rem; align-items: flex-end; margin-bottom: 1.7rem; }
.page-heading p { margin: 0; max-width: 52rem; font-size: 1.12rem; }
.eyebrow { font-size: .72rem; letter-spacing: .16em; font-weight: 600; color: var(--mint-deep); text-transform: uppercase; }
.muted { color: var(--muted); }
.small { font-size: .85rem; }
.button, button.primary, button.secondary, a.button {
  display: inline-flex; align-items: center; justify-content: center; gap: .4rem;
  border: 0; border-radius: 999px; padding: .7rem 1.05rem; text-decoration: none; cursor: pointer; background: var(--navy); color: #fff;
}
button.secondary, a.button.secondary, .button.secondary { background: #fff; color: var(--navy); border: 1px solid var(--line); }
.button.mint, a.button.mint { background: var(--mint); color: var(--navy); }
.button.compact { padding: .45rem .8rem; font-size: .9rem; }
.button.full, button.full { width: 100%; }
button.danger { background: var(--danger); color: #fff; }
button:disabled { opacity: .45; cursor: not-allowed; }
.icon-btn { width: 40px; height: 40px; border-radius: 12px; border: 1px solid var(--line); background: #fff; display: grid; place-items: center; cursor: pointer; }
.text-link { color: var(--navy); font-weight: 600; text-decoration: none; display: inline-flex; align-items: center; gap: .25rem; }
.pill { display: inline-flex; align-items: center; gap: .3rem; border-radius: 999px; background: #efe7d6; padding: .28rem .65rem; font-size: .8rem; }
.pill.good { background: #d8f3e4; color: var(--ok); }
.panel { background: var(--paper-2); border: 1px solid var(--line); border-radius: var(--radius); padding: 1.1rem 1.15rem; box-shadow: 0 1px 0 rgba(255,255,255,.7) inset; }
.section-heading { display: flex; justify-content: space-between; align-items: end; gap: 1rem; margin: 2rem 0 1rem; }
.path-progress {
  display: inline-flex; align-items: baseline; gap: .35rem;
  background: #fff; border: 1px solid var(--line); border-radius: 999px;
  padding: .45rem .9rem; color: var(--navy); font-size: 1rem; letter-spacing: 0;
}
.path-progress strong { font-family: "DM Serif Display", serif; font-size: 1.35rem; }
.path-progress.done { background: #d8f3e4; border-color: #b7e0c8; color: var(--ok); }
.path-block { margin-bottom: 2.2rem; }
.overview-grid { display: grid; grid-template-columns: 1.7fr .95fr; gap: 1.15rem; }
.flight-hero { position: relative; min-height: 400px; border-radius: 28px; overflow: hidden; color: #fff; }
.hero-image { position: absolute; inset: 0; background: #123 url("./assets/drone-hero.jpg") center/cover; }
.hero-image:after { content: ""; position: absolute; inset: 0; background: linear-gradient(90deg, rgba(16,40,59,.72), rgba(16,40,59,.12) 70%); }
.hero-content { position: relative; z-index: 1; padding: 2.4rem; max-width: 34rem; }
.hero-label { letter-spacing: .16em; font-size: .78rem; color: var(--mint); }
.hero-content h2 { font-size: 2.85rem; }
.hero-content p { color: #dce8ee; }
.hero-coordinate { position: absolute; right: 1.1rem; bottom: 1rem; z-index: 1; letter-spacing: .14em; font-size: .7rem; color: #fff; }
.readiness-card { background: var(--navy); color: #fff; border-radius: 28px; padding: 1.3rem; display: flex; flex-direction: column; gap: .8rem; }
.readiness-card .eyebrow { color: var(--mint); }
.progress-ring {
  width: 132px; height: 132px; margin: .2rem auto; border-radius: 50%;
  background: conic-gradient(var(--mint) var(--progress), rgba(255,255,255,.12) 0);
  display: grid; place-items: center;
}
.progress-ring span { width: 102px; height: 102px; border-radius: 50%; background: var(--navy); display: grid; place-items: center; font-size: 2rem; }
.progress-ring small { font-size: .9rem; }
.readiness-stats { display: grid; grid-template-columns: 1fr 1fr; gap: .6rem; }
.readiness-stats span { display: block; color: #9eb0bb; font-size: .8rem; }
.readiness-card .text-link { color: var(--mint); }
.stat-strip { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1rem; margin: 1.3rem 0 1.6rem; }
.stat-strip > div, .bank-stats { display: flex; gap: .8rem; align-items: flex-start; }
.stat-strip > div { background: #fff; border: 1px solid var(--line); border-radius: 18px; padding: 1.1rem 1.2rem; }
.stat-strip small { display: block; color: var(--muted); }
.stat-strip strong { font-size: 1.15rem; }
.chapter-grid, .tool-grid, .vocab-grid, .takeaway-grid, .bank-stats, .results-areas, .source-columns { display: grid; gap: 1.1rem; }
.chapter-grid { grid-template-columns: repeat(auto-fit, minmax(min(100%, 340px), 1fr)); }
.tool-grid { grid-template-columns: repeat(3, 1fr); }
.chapter-card, .tool-card, .vocab-card {
  background: #fff; border: 1px solid var(--line); border-radius: 22px; padding: 1.35rem 1.4rem; text-decoration: none; display: flex; flex-direction: column; gap: .45rem; min-height: 280px; transition: transform .18s ease, box-shadow .18s ease;
}
.chapter-card:hover, .tool-card:hover { transform: translateY(-4px); box-shadow: var(--shadow); }
.chapter-card.is-complete { background: linear-gradient(#fff, #f2faf6); border-color: #c5e6d4; }
.card-top, .card-bottom { display: flex; justify-content: space-between; align-items: center; }
.tile-icon { width: 48px; height: 48px; border-radius: 14px; background: #eaf8f4; color: var(--navy); display: grid; place-items: center; }
.chapter-number { font-family: "DM Serif Display", serif; color: var(--muted); }
.chapter-status { font-size: .82rem; font-weight: 700; letter-spacing: .04em; text-transform: uppercase; color: var(--muted); background: #f4efe4; border-radius: 999px; padding: .28rem .7rem; }
.chapter-status.is-done { background: #d8f3e4; color: var(--ok); display: inline-flex; align-items: center; gap: .3rem; }
.card-meta { display: flex; flex-wrap: wrap; gap: .45rem; list-style: none; padding: 0; margin: .4rem 0 .2rem; color: var(--muted); font-size: .9rem; }
.card-meta li { background: #f7f1e6; border-radius: 999px; padding: .22rem .65rem; }
.chapter-card p { flex: 1; font-size: 1.02rem; }
.open-cta { font-weight: 700; color: var(--navy); display: inline-flex; align-items: center; gap: .3rem; }
.complete-text { color: var(--ok); }
.course-intro, .notice-banner, .resume-banner, .result-banner { display: flex; justify-content: space-between; gap: 1.4rem; align-items: center; background: #fff; border: 1px solid var(--line); border-radius: 22px; padding: 1.3rem 1.5rem; margin-bottom: 1.2rem; }
.course-intro p { font-size: 1.08rem; max-width: 52rem; }
.intro-points { margin: .7rem 0 0; padding-left: 1.15rem; color: #33444d; }
.intro-points li { margin: .3rem 0; }
.notice-banner { align-items: flex-start; background: #edf7f4; }
.tabs { display: flex; gap: .4rem; flex-wrap: wrap; margin-bottom: 1rem; }
.tabs button, .tabs a, .segmented button {
  border: 1px solid var(--line); background: #fff; border-radius: 999px; padding: .45rem .8rem; text-decoration: none; cursor: pointer;
}
.tabs .selected, .segmented .selected, .metar-tokens .selected { background: var(--navy); color: #fff; border-color: var(--navy); }
.lesson-layout { display: grid; grid-template-columns: minmax(0, 1fr) 280px; gap: 1.4rem; }
.lesson-article, .lesson-section { background: #fff; border: 1px solid var(--line); border-radius: 22px; padding: 1.45rem 1.6rem; }
.lesson-section { margin-top: 1rem; }
.lesson-section p, .lesson-section li { font-size: 1.08rem; line-height: 1.7; }
.lesson-section ul { padding-left: 1.2rem; }
.lesson-number { color: var(--muted); letter-spacing: .12em; font-size: .78rem; }
.objectives { background: #edf7f4; border-radius: 16px; padding: 1.15rem 1.25rem; }
.objectives li { margin: .4rem 0; font-size: 1.05rem; }
.worked-example, .exam-trap, .callout, .term-example { border-radius: 14px; padding: .85rem 1rem; margin-top: .8rem; }
.worked-example { background: #f7f1e2; }
.exam-trap, .feedback.incorrect { background: #fbecea; }
.callout { background: #eef3f7; }
.lesson-toc { position: sticky; top: 5.2rem; align-self: start; background: #fff; border: 1px solid var(--line); border-radius: 18px; padding: .9rem; display: flex; flex-direction: column; gap: .45rem; }
.lesson-toc a { text-decoration: none; display: flex; gap: .5rem; color: var(--ink); }
.toc-practice { margin-top: .6rem; padding-top: .7rem; border-top: 1px solid var(--line); }
.lesson-finish { display: flex; gap: .7rem; align-items: center; flex-wrap: wrap; margin-top: 1.2rem; background: #fff; border: 1px solid var(--line); border-radius: 18px; padding: 1rem; }
.takeaway-grid { grid-template-columns: repeat(auto-fit, minmax(min(100%, 280px), 1fr)); }
.takeaway-grid .panel p { font-size: 1.08rem; line-height: 1.6; }
.step-number { font-family: "DM Serif Display", serif; color: var(--mint-deep); }
.toolbar, .search-toolbar, .button-row { display: flex; flex-wrap: wrap; gap: .6rem; align-items: center; margin-bottom: .8rem; }
.search-box, select, input[type="search"] { background: #fff; border: 1px solid var(--line); border-radius: 12px; padding: .55rem .7rem; min-width: 180px; }
.vocab-grid { grid-template-columns: repeat(auto-fit, minmax(min(100%, 280px), 1fr)); }
.flashcard {
  width: min(640px, 100%); min-height: 280px; margin: 1rem auto; border: 0; border-radius: 28px; background: #fff;
  box-shadow: var(--shadow); display: flex; flex-direction: column; justify-content: center; gap: .6rem; padding: 2rem; cursor: pointer; text-align: left;
}
.flash-term { font-family: "DM Serif Display", serif; font-size: 2rem; }
.flash-controls { display: flex; justify-content: center; gap: .6rem; }
.flash-meta, .keyboard-hint { text-align: center; color: var(--muted); }
.exam-options { display: grid; grid-template-columns: 1.35fr 1fr; gap: 1.2rem; }
.exam-feature { background: var(--navy); color: #fff; border-radius: 28px; padding: 1.5rem; }
.exam-feature p { color: #d5e2e8; }
.exam-facts { display: flex; gap: 1rem; margin: 1rem 0; }
.bank-stats { grid-template-columns: repeat(3, 1fr); }
.bank-stats .panel, .results-areas .panel { display: block; }
.quiz-layout { display: grid; grid-template-columns: minmax(0, 1fr) 260px; gap: 1.2rem; }
.question-panel { background: #fff; border: 1px solid var(--line); border-radius: 22px; padding: 1.4rem 1.5rem; }
.question-stem { font-size: 1.45rem; line-height: 1.35; }
.question-meta, .session-top, .question-actions { display: flex; justify-content: space-between; gap: .7rem; align-items: center; flex-wrap: wrap; }
.options { display: flex; flex-direction: column; gap: .55rem; margin: 1rem 0; }
.option { display: flex; gap: .7rem; align-items: flex-start; text-align: left; background: #fff; border: 1px solid var(--line); border-radius: 14px; padding: .8rem; cursor: pointer; }
.option.selected { border-color: var(--navy); box-shadow: 0 0 0 3px rgba(16,40,59,.12); }
.option.correct-option { border-color: var(--ok); background: #eaf7ef; }
.option.wrong-option { border-color: var(--danger); background: #fbecea; }
.option-letter { width: 26px; height: 26px; border-radius: 50%; background: #efe7d6; display: grid; place-items: center; font-weight: 700; flex: none; }
.question-grid { display: grid; grid-template-columns: repeat(5, 1fr); gap: .35rem; }
.question-grid button { height: 36px; border-radius: 8px; border: 1px solid var(--line); background: #fff; cursor: pointer; }
.question-grid .answered { background: var(--navy); color: #fff; }
.question-grid .current { outline: 2px solid var(--mint-deep); }
.question-grid .flagged, .text-link.flagged { box-shadow: 0 0 0 2px var(--gold); }
.question-figure, .review-figure { margin: .8rem 0; }
.question-figure img, .review-figure { border-radius: 12px; border: 1px solid var(--line); }
.question-provenance, .session-clock { color: var(--muted); font-size: .85rem; }
.result-score { font-family: "DM Serif Display", serif; font-size: 4rem; line-height: 1; color: var(--navy); }
.result-score span { font-size: 1.4rem; }
.review-item { background: #fff; border: 1px solid var(--line); border-radius: 14px; margin-bottom: .5rem; }
.review-item summary { display: flex; gap: .7rem; align-items: center; padding: .7rem .9rem; cursor: pointer; }
.review-marker { width: 28px; height: 28px; border-radius: 50%; display: grid; place-items: center; color: #fff; flex: none; }
.review-marker.right { background: var(--ok); }
.review-marker.wrong { background: var(--danger); }
.review-content { padding: 0 1rem 1rem; }
.feedback { border-radius: 12px; padding: .8rem 1rem; margin: .8rem 0; }
.feedback.correct { background: #eaf7ef; }
.stat-list { display: grid; gap: .45rem; }
.stat-list > div { display: flex; justify-content: space-between; gap: 1rem; border-bottom: 1px dashed var(--line); padding-bottom: .35rem; }
.blueprint-row { display: grid; grid-template-columns: 1fr auto 140px; gap: .6rem; align-items: center; margin: .45rem 0; }
.blueprint-row .progress { background: #efe7d6; }
.cert-steps { padding-left: 1.1rem; }
.cert-steps li { margin: .45rem 0; }
.source-library { display: grid; gap: .5rem; }
.source-library a { display: flex; gap: .7rem; align-items: center; background: #fff; border: 1px solid var(--line); border-radius: 14px; padding: .8rem 1rem; text-decoration: none; }
.source-library small { display: block; color: var(--muted); }
.source-icon { color: var(--mint-deep); }
.table-wrap { overflow: auto; }
table { width: 100%; border-collapse: collapse; }
th, td { text-align: left; padding: .55rem .4rem; border-bottom: 1px solid var(--line); }
.empty-state, .empty-history { text-align: center; padding: 2.5rem 1rem; color: var(--muted); }
.lab-panel { background: #fff; }
.lab-layout { display: grid; grid-template-columns: 1.1fr .9fr; gap: 1rem; }
.lab-output { background: #edf7f4; border-radius: 16px; padding: 1rem; }
.airspace-diagram { display: grid; gap: .35rem; }
.air-band, .ground-band, .shelf { border-radius: 10px; padding: .55rem .7rem; color: #fff; border: 0; }
.band-a { background: #2a4d8f; }
.band-e { background: #3d7ea6; }
.ground-band { background: #4e7a43; }
.air-shelves { display: grid; grid-template-columns: repeat(4, 1fr); gap: .35rem; }
.shelf-b { background: #355fbd; }
.shelf-c { background: #a43d7a; }
.shelf-d { background: #2f6f9e; }
.shelf-es { background: #8a3d8f; }
.chart-line { height: 8px; border-radius: 99px; margin: .5rem 0; background: #a43d7a; }
.line-B { background: #355fbd; }
.line-C { background: #a43d7a; }
.line-D { background: #2f6f9e; }
.line-E-surface { background: #8a3d8f; border-bottom: 2px dashed #fff; }
.line-E-700 { background: linear-gradient(#a43d7a, #edf7f4); }
.line-E-1200 { background: linear-gradient(#355fbd, #edf7f4); }
.line-G { background: #4e7a43; }
.metar-tokens, .segmented { display: flex; flex-wrap: wrap; gap: .4rem; margin: .6rem 0 1rem; }
.metar-tokens button { border: 1px solid var(--line); background: #fff; border-radius: 10px; padding: .45rem .6rem; cursor: pointer; }
.range-field { display: grid; grid-template-columns: 1fr auto; gap: .35rem; margin: .7rem 0; }
.range-field input { grid-column: 1 / -1; }
.big-number { font-family: "DM Serif Display", serif; font-size: 2.6rem; }
.big-number span { display: block; font-family: Outfit, sans-serif; font-size: .85rem; color: var(--muted); }
.cg-track { height: 12px; background: #efe7d6; border-radius: 99px; position: relative; margin: .8rem 0; }
.cg-track span { position: absolute; top: -4px; width: 12px; height: 20px; background: var(--navy); border-radius: 4px; }
.check-row { display: flex; gap: .55rem; align-items: flex-start; margin: .45rem 0; }
.plain-list { padding-left: 1.1rem; }
.report { background: #10283b; color: #d7f7ef; padding: 1rem; border-radius: 12px; overflow: auto; }
.inline-check { display: flex; gap: .4rem; align-items: center; }
.inline-check.roomy { margin: .7rem 0; }
.field-label { display: block; font-size: .82rem; margin: .5rem 0 .25rem; }
.divider-label { text-align: center; color: var(--muted); margin: .9rem 0; font-size: .8rem; letter-spacing: .12em; }
.spaced { margin-top: 1rem; }
dialog.modal { border: 0; border-radius: 18px; padding: 1.2rem; width: min(420px, 92vw); box-shadow: var(--shadow); }
dialog.modal::backdrop { background: rgba(16,40,59,.45); }
#toast { position: fixed; right: 1rem; bottom: 1rem; background: var(--navy); color: #fff; padding: .7rem 1rem; border-radius: 12px; opacity: 0; transform: translateY(8px); transition: .25s; pointer-events: none; }
#toast.visible { opacity: 1; transform: none; }
.term-ref {
  color: #1a6fd4;
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-thickness: 1.5px;
  cursor: help;
  font: inherit;
  background: none;
  padding: 0;
  border: 0;
}
.term-ref:hover, .term-ref:focus-visible { color: #0d4ea8; background: rgba(26,111,212,.08); border-radius: 3px; }
#term-overlay {
  position: fixed; inset: 0; z-index: 40;
  background: rgba(16,40,59,.45);
  display: grid; place-items: center; padding: 1rem;
}
#term-overlay[hidden] { display: none; }
.term-pop {
  position: relative; width: min(440px, 92vw);
  background: #fff; border-radius: 22px; padding: 1.35rem 1.4rem 1.2rem;
  box-shadow: var(--shadow);
}
.term-pop h2 { margin-right: 2rem; }
.term-pop-close {
  position: absolute; top: .75rem; right: .75rem;
  width: 36px; height: 36px; border-radius: 10px;
  border: 1px solid var(--line); background: #fff;
  display: grid; place-items: center; cursor: pointer;
}
.term-pop .term-example { margin-top: .85rem; }

@media (max-width: 1100px) {
  .tool-grid { grid-template-columns: 1fr; }
}
@media (max-width: 980px) {
  .overview-grid, .lesson-layout, .exam-options, .quiz-layout, .lab-layout, .source-columns, .bank-stats, .stat-strip, .tool-grid { grid-template-columns: 1fr; }
  .main { padding: 1.3rem 1.1rem 2.5rem; }
  .sidebar { position: fixed; z-index: 20; transform: none; }
  .sidebar.collapsed { display: none; }
  .sidebar-backdrop { display: block; position: fixed; inset: 0; background: rgba(16,40,59,.35); z-index: 15; }
  .workspace.wide .sidebar-backdrop { display: none; }
}