/*
 * F450 Flight Lab visual system
 * 本文件覆盖基础 Carbon 样式，保留原有 DOM、状态类和安全语义。
 * 所有颜色、图形和状态均为本地离线 UI，不表示真实设备测量结果。
 */

:root {
  --navy-950: #061322;
  --navy-900: #091b2e;
  --navy-850: #0b2137;
  --navy-800: #0d2942;
  --navy-700: #153d5b;
  --navy-600: #1c5274;
  --primary: #1683d8;
  --primary-dark: #0d5fa5;
  --primary-soft: #e7f3fd;
  --teal: #13a6a0;
  --cyan: #44cdd4;
  --ink: #13263a;
  --text-secondary: #52687b;
  --muted: #7890a2;
  --workbench: #eef2f6;
  --surface: #ffffff;
  --surface-tint: #f7fafc;
  --line: #d6e0e8;
  --line-strong: #adbecb;
  --success: #118876;
  --success-soft: #e7f6f1;
  --warning: #a86600;
  --warning-bg: #fff6dd;
  --warning-line: #e5b64a;
  --danger: #c73a43;
  --danger-soft: #fff0f1;
  --danger-line: #e07b81;
  --neutral-soft: #e8eef2;
  --radius-control: 10px;
  --radius-card: 16px;
  --radius-lg: 20px;
  --shadow-soft: 0 10px 26px rgba(16, 43, 66, .07);
  --shadow-card: 0 18px 42px rgba(16, 43, 66, .09);
  --shadow-dark: 0 18px 36px rgba(2, 13, 27, .28);
  --font-sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  font-family: var(--font-sans);
  color: var(--ink);
  background: var(--workbench);
}

* { box-sizing: border-box; }
html { min-width: 320px; background: var(--workbench); scroll-behavior: smooth; }
body {
  min-height: 100vh;
  margin: 0;
  color: var(--ink);
  background: var(--workbench);
  font-size: 16px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}
body::before {
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  content: "";
  background-image: linear-gradient(rgba(91, 126, 151, .035) 1px, transparent 1px), linear-gradient(90deg, rgba(91, 126, 151, .035) 1px, transparent 1px);
  background-size: 32px 32px;
  mask-image: linear-gradient(to bottom, rgba(0, 0, 0, .55), transparent 72%);
}
button, input, select, textarea { font: inherit; }
button { cursor: pointer; }
button:focus-visible, input:focus-visible, select:focus-visible, textarea:focus-visible, a:focus-visible {
  outline: 3px solid rgba(68, 205, 212, .9);
  outline-offset: 2px;
}
.skip-link { border-radius: 8px; }

/* 顶部与导航：深海军蓝工作台骨架 */
.topbar {
  position: sticky;
  top: 0;
  z-index: 40;
  display: flex;
  min-height: 72px;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 10px 28px;
  color: #f7fbff;
  background: var(--navy-950);
  border-bottom: 1px solid rgba(126, 195, 224, .18);
  box-shadow: 0 8px 24px rgba(3, 16, 31, .18);
}
.topbar::after {
  position: absolute;
  right: 0;
  bottom: -1px;
  left: 0;
  height: 2px;
  content: "";
  background: linear-gradient(90deg, transparent 0, var(--teal) 34%, var(--cyan) 60%, transparent 100%);
  opacity: .72;
}
.brand { gap: 12px; }
.brand-mark {
  position: relative;
  display: grid;
  width: 38px;
  height: 38px;
  place-items: center;
  color: var(--cyan);
  background: linear-gradient(145deg, #16496b, #0d263e);
  border: 1px solid rgba(68, 205, 212, .45);
  border-radius: 12px;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, .08), 0 5px 14px rgba(0, 0, 0, .18);
  font-size: 18px;
}
.brand-mark::after { position: absolute; width: 8px; height: 8px; border: 1px solid var(--cyan); border-radius: 50%; content: ""; }
.brand strong, .brand small { display: block; }
.brand strong { color: #f6fbff; font-size: 16px; font-weight: 700; letter-spacing: .02em; }
.brand small { margin-top: 1px; color: #8eb2c8; font-size: 11px; letter-spacing: .09em; }
.topbar-actions { gap: 12px; }
.topbar-context { color: #dceaf2; font-size: 13px; }
.offline-badge { color: #6ed8cf; font-size: 12px; font-weight: 600; }
.offline-badge::first-letter { color: var(--teal); }

.app-shell { display: grid; grid-template-columns: 300px minmax(0, 1fr); min-height: calc(100vh - 72px); }
.sidebar {
  position: sticky;
  top: 72px;
  z-index: 20;
  min-width: 0;
  height: calc(100vh - 72px);
  overflow: auto;
  padding: 28px 17px 30px;
  color: #edf6fb;
  background: linear-gradient(160deg, var(--navy-900) 0%, var(--navy-950) 70%);
  border-right: 1px solid rgba(130, 194, 219, .17);
  scrollbar-color: #27516b transparent;
}
.sidebar::before {
  position: absolute;
  top: 0;
  right: 0;
  width: 1px;
  height: 280px;
  content: "";
  background: linear-gradient(180deg, var(--cyan), transparent);
  opacity: .35;
}
.course-meta { padding: 0 9px 24px; border-bottom-color: rgba(129, 187, 210, .17); }
.eyebrow, .flight-overline {
  color: #6ed8cf;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: .14em;
  line-height: 1.4;
}
.course-meta h1 { color: #fff; font-size: 20px; line-height: 1.38; letter-spacing: -.015em; }
.course-meta p:not(.eyebrow) { color: #9cb7c8; font-size: 13px; line-height: 1.65; }
.nav-group { padding-top: 22px; }
.nav-group + .nav-group { margin-top: 8px; border-top-color: rgba(129, 187, 210, .15); }
.nav-section-heading, .panel-heading { padding: 0 9px; }
.nav-section-heading h2, .panel-heading h2 { color: #e7f4f8; font-size: 13px; font-weight: 700; letter-spacing: .03em; }
.nav-section-heading span, .panel-heading span { color: #70cfd1; font-size: 11px; font-family: var(--font-mono); }
.course-nav, .result-nav { gap: 5px; padding-top: 11px; }
.nav-button {
  min-height: 50px;
  gap: 10px;
  padding: 8px 9px;
  color: #b8cedb;
  background: transparent;
  border: 1px solid transparent;
  border-radius: 10px;
}
.nav-button:hover { color: #f8fcff; background: rgba(89, 177, 206, .12); border-color: rgba(89, 177, 206, .14); }
.nav-button.is-active {
  color: #fff;
  background: linear-gradient(90deg, rgba(26, 126, 177, .48), rgba(18, 68, 94, .4));
  border-color: rgba(91, 199, 212, .32);
  border-left: 3px solid var(--cyan);
  padding-left: 7px;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, .04);
}
.nav-number { color: #6f96aa; font-size: 12px; }
.nav-button.is-active .nav-number { color: var(--cyan); }
.nav-copy strong { font-size: 13px; }
.nav-copy small { color: #7898aa; font-size: 11px; }
.nav-button.is-active .nav-copy small { color: #bee4ed; }
.nav-button.good .nav-copy small { color: #7cdbc7; }
.nav-checkpoint, .gate-id {
  min-width: 30px;
  height: 22px;
  color: #9ee4e0;
  background: rgba(20, 137, 139, .2);
  border: 1px solid rgba(80, 205, 196, .45);
  border-radius: 7px;
  font-family: var(--font-mono);
  font-size: 10px;
}
.gate-list { gap: 8px; margin-top: 12px; }
.gate-card { padding: 11px; background: rgba(4, 20, 35, .54); border-color: rgba(129, 187, 210, .2); border-left-width: 3px; border-radius: 10px; }
.gate-card.good { border-left-color: #45c6a7; background: rgba(15, 115, 104, .16); }
.gate-card.active { border-left-color: var(--cyan); }
.gate-card.danger { border-left-color: #ea7d85; }
.gate-card h3 { color: #e7f4f8; font-size: 12px; }
.gate-card p, .section-helper { color: #87a4b5; font-size: 11px; }
.status-token, .status-chip { border-radius: 999px; font-size: 11px; }
.status-token { color: #b9cfda; background: rgba(88, 129, 148, .16); border-color: rgba(131, 178, 197, .24); }
.status-token.good, .status-chip.good { color: #176b5d; background: #dff4ed; border-color: #8bcfbe; }
.status-token.warn, .status-chip.warn { color: #855504; background: #fff2ca; border-color: #e6c46b; }
.progress-panel { margin-top: 24px; padding: 18px 9px 0; border-top-color: rgba(129, 187, 210, .17); }
.progress-panel-heading { color: #9eb8c7; font-size: 12px; }
.progress-panel-heading strong { color: #e4f2f5; }
.progress-track { height: 7px; margin-top: 10px; background: #12314a; border-radius: 99px; }
.progress-fill { background: linear-gradient(90deg, var(--teal), var(--cyan)); border-radius: inherit; }
.progress-panel p { color: #6e8c9e; font-size: 11px; }

/* 阅读区基础层 */
.main-content {
  width: 100%;
  max-width: none;
  margin: 0;
  padding: 30px clamp(20px, 4vw, 64px) 72px;
}
.safety-strip {
  display: flex;
  min-height: 50px;
  align-items: flex-start;
  gap: 10px;
  max-width: 1440px;
  margin: 0 auto 24px;
  padding: 13px 17px;
  color: #775000;
  background: var(--warning-bg);
  border: 1px solid #e9c56e;
  border-left: 4px solid var(--warning-line);
  border-radius: 12px;
  box-shadow: 0 5px 16px rgba(154, 106, 12, .06);
  font-size: 13px;
}
.safety-strip strong { color: #523600; }
.learning-page { max-width: 1440px; margin: 0 auto; padding-top: 0; }
.breadcrumb { color: var(--muted); font-size: 12px; letter-spacing: .02em; }
.breadcrumb span { color: #b0bdc7; }
.page-heading { gap: 42px; margin-bottom: 28px; }
.page-heading h2 { color: var(--ink); font-size: clamp(28px, 3vw, 42px); font-weight: 700; letter-spacing: -.035em; line-height: 1.17; }
.page-description { max-width: 790px; margin-top: 14px; color: var(--text-secondary); font-size: 15px; line-height: 1.7; }
.chapter-tag {
  color: var(--primary-dark);
  background: var(--primary-soft);
  border-color: #a7d3ee;
  border-radius: 999px;
  font-size: 12px;
}
.page-context { border-color: var(--line); border-radius: 14px; box-shadow: var(--shadow-soft); }
.page-context > div { padding: 14px 16px; border-color: var(--line); }
.page-context dt { color: var(--muted); font-size: 11px; letter-spacing: .05em; }
.page-context dd { color: var(--ink); font-size: 13px; font-weight: 600; }
.task-guide { gap: 12px; margin-bottom: 28px; }
.guide-card {
  min-height: 140px;
  padding: 18px;
  background: rgba(255, 255, 255, .88);
  border: 1px solid var(--line);
  border-top: 3px solid var(--teal);
  border-radius: 14px;
  box-shadow: var(--shadow-soft);
}
.guide-card h3 { color: var(--ink); font-size: 15px; }
.guide-card ul { color: var(--text-secondary); font-size: 13px; }
.guide-card li::marker { color: var(--teal); }
.flight-guide { margin-bottom: 24px; background: var(--surface-tint); border: 1px solid var(--line); border-radius: 14px; }
.flight-guide summary { padding: 13px 16px; color: var(--ink); font-size: 13px; font-weight: 700; cursor: pointer; }
.flight-guide summary span { margin-left: 8px; color: var(--muted); font-weight: 400; }
.flight-guide[open] .task-guide { margin: 0; padding: 0 12px 12px; }

/* 通用卡片、表单、按钮 */
.card {
  min-width: 0;
  background: rgba(255, 255, 255, .96);
  border: 1px solid var(--line);
  border-radius: var(--radius-card);
  box-shadow: var(--shadow-soft);
}
.card-pad { padding: 26px; }
.section-gap { margin-top: 24px; }
.grid-2, .mission-grid, .report-grid, .assembly-layout, .gs-layout { gap: 20px; }
.grid-3 { gap: 16px; }
.section-heading { margin-bottom: 18px; }
.section-heading h3, .activity-head h3 { color: var(--ink); font-size: 20px; letter-spacing: -.015em; }
.section-heading > p, .activity-head p { color: var(--text-secondary); font-size: 14px; }
.section-kicker { color: var(--muted); font-size: 11px; letter-spacing: .08em; }
.button {
  min-height: 44px;
  padding: 10px 17px;
  color: #fff;
  background: var(--navy-800);
  border: 1px solid transparent;
  border-radius: var(--radius-control);
  box-shadow: 0 4px 10px rgba(10, 39, 63, .1);
  font-size: 14px;
  font-weight: 700;
  line-height: 1.35;
  transition: background-color .2s ease, border-color .2s ease, box-shadow .2s ease, transform .2s ease;
}
.button:hover { background: var(--navy-700); box-shadow: 0 7px 16px rgba(10, 39, 63, .16); transform: translateY(-1px); }
.button-primary { background: linear-gradient(135deg, #1889dc, #0f6bb5); }
.button-primary:hover { background: linear-gradient(135deg, #1a91e7, #1264a9); }
.button-success { background: var(--teal); }
.button-success:hover { background: #0b897f; }
.button-danger { background: var(--danger); }
.button-danger:hover { background: #aa2f38; }
.button-warning { color: #4d3300; background: #edc45c; }
.button-quiet { min-height: 38px; padding: 7px 12px; color: #d3e5ee; background: rgba(255, 255, 255, .07); border-color: rgba(155, 205, 222, .28); box-shadow: none; font-size: 12px; }
.button-quiet:hover { color: #fff; background: rgba(109, 207, 210, .18); }
.button-ghost { color: var(--primary-dark); background: var(--primary-soft); border-color: #abd3e9; box-shadow: none; }
.button-ghost:hover { color: var(--navy-800); background: #d8edf9; }
.button[disabled] { box-shadow: none; }
.button-row { gap: 10px; margin-top: 18px; }
.callout { gap: 13px; padding: 16px 18px; border-radius: 13px; line-height: 1.65; }
.callout-safe { color: #745000; background: var(--warning-bg); border-color: #e8c66d; }
.callout-info { color: #145b83; background: var(--primary-soft); border-color: #a9d3ea; }
.callout-danger { color: #8a2630; background: var(--danger-soft); border-color: #e6a0a4; }
.callout-icon { flex-basis: 30px; width: 30px; height: 30px; border-radius: 9px; }
.choice, .check-row, .quiz-option {
  min-height: 50px;
  padding: 13px 14px;
  color: var(--ink);
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 11px;
  transition: border-color .2s ease, background-color .2s ease;
}
.choice:hover, .check-row:hover, .quiz-option:hover { background: #f2f8fc; border-color: #7fbddd; }
.choice input, .check-row input, .quiz-option input { accent-color: var(--primary); }
.choice.is-danger { color: #862832; background: var(--danger-soft); border-color: #e6a0a4; }
.score-pill { color: var(--primary-dark); background: var(--primary-soft); border-color: #a6d2e9; border-radius: 999px; }
.feedback { border-radius: 12px; }
.feedback.good { color: #176b5d; background: var(--success-soft); border-color: #95d5c5; }
.feedback.warn { color: #855504; background: var(--warning-bg); border-color: #e6c46b; }
.feedback.bad { color: #862832; background: var(--danger-soft); border-color: #e6a0a4; }
.form-grid { gap: 16px; }
.form-field { gap: 7px; }
.form-field label { color: var(--ink); font-size: 13px; font-weight: 700; }
.form-field input, .form-field select, .form-field textarea, .motor-table select, .lab-controls select {
  width: 100%;
  padding: 11px 13px;
  color: var(--ink);
  background: #fbfdfe;
  border: 1px solid var(--line-strong);
  border-radius: 10px;
  transition: border-color .2s ease, box-shadow .2s ease;
}
.form-field input:focus, .form-field select:focus, .form-field textarea:focus, .motor-table select:focus, .lab-controls select:focus { border-color: var(--primary); box-shadow: 0 0 0 3px rgba(22, 131, 216, .13); outline: 0; }
.form-field textarea { min-height: 110px; }
.form-help { color: var(--text-secondary); font-size: 13px; }
.image-card { overflow: hidden; border-radius: 15px; }
.image-card figcaption { color: var(--text-secondary); background: var(--surface-tint); font-size: 12px; }
.motor-table { overflow: hidden; border-color: var(--line); border-radius: 12px; }
.motor-table th { color: var(--text-secondary); background: #f2f6f8; }
.motor-table th, .motor-table td { border-color: var(--line); }

/* 首页：航空工程视觉主场 */
.flight-breadcrumb { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 10px; margin: 0 2px 16px; color: var(--muted); font-family: var(--font-mono); font-size: 11px; letter-spacing: .04em; }
.flight-breadcrumb span + span { color: #7195a9; }
.flight-hero {
  position: relative;
  min-height: 512px;
  overflow: hidden;
  isolation: isolate;
  background: var(--navy-950);
  border: 1px solid #193e59;
  border-radius: 22px;
  box-shadow: var(--shadow-dark);
}
.flight-hero::before { position: absolute; inset: 0; z-index: 1; content: ""; background: linear-gradient(105deg, rgba(4, 18, 33, .98) 0%, rgba(5, 23, 40, .88) 33%, rgba(5, 25, 42, .18) 68%, rgba(5, 21, 37, .1)); }
.flight-hero::after { position: absolute; top: 32px; right: 34px; z-index: 3; width: 42px; height: 42px; border-top: 1px solid rgba(68, 205, 212, .7); border-right: 1px solid rgba(68, 205, 212, .7); content: ""; opacity: .75; }
.flight-hero-image { position: absolute; inset: 0; z-index: 0; width: 100%; height: 100%; object-fit: cover; object-position: center; }
.flight-hero-shade { display: none; }
.flight-hero-copy { position: relative; z-index: 2; display: flex; width: min(55%, 620px); min-height: 512px; flex-direction: column; align-items: flex-start; justify-content: center; padding: 54px 48px; }
.flight-hero-copy .flight-overline { color: var(--cyan); }
.flight-hero-label { margin: 17px 0 0; color: #a5c8d9; font-size: 13px; letter-spacing: .06em; }
.flight-hero h2 { max-width: 600px; margin: 12px 0 0; color: #fff; font-size: clamp(38px, 3.35vw, 48px); font-weight: 700; letter-spacing: -.06em; line-height: 1.08; }
.flight-hero h2 span { color: var(--cyan); }
.flight-hero-copy > p:not(.flight-hero-label) { margin: 22px 0 0; color: #c2d7e2; font-size: 16px; line-height: 1.75; }
.flight-hero .button-row { margin-top: 29px; }
.flight-cta { min-width: 154px; color: #052033; background: var(--cyan); box-shadow: 0 9px 26px rgba(54, 200, 209, .25); }
.flight-cta:hover { color: #041929; background: #77e2e4; }
.flight-glass { color: #e0f0f4; background: rgba(255, 255, 255, .08); border-color: rgba(191, 231, 237, .36); box-shadow: none; }
.flight-glass:hover { color: #fff; background: rgba(255, 255, 255, .16); }
.flight-hero-foot { display: flex; align-items: center; gap: 13px; margin-top: 42px; color: #89aabd; font-family: var(--font-mono); font-size: 10px; letter-spacing: .05em; }
.flight-hero-foot i { display: block; width: 32px; height: 1px; background: var(--teal); }
.flight-image-caption { position: absolute; right: 20px; bottom: 17px; z-index: 3; padding: 5px 9px; color: rgba(215, 236, 241, .74); background: rgba(2, 15, 27, .48); border: 1px solid rgba(151, 208, 219, .2); border-radius: 7px; font-family: var(--font-mono); font-size: 10px; }
.flight-metrics { display: grid; grid-template-columns: 1.2fr 1fr 1fr; margin-top: 16px; overflow: hidden; background: var(--surface); border: 1px solid var(--line); border-radius: 15px; box-shadow: var(--shadow-soft); }
.flight-metrics > div { position: relative; display: flex; min-height: 100px; align-items: center; gap: 13px; padding: 18px 22px; }
.flight-metrics > div + div { border-left: 1px solid var(--line); }
.metric-icon { display: grid; width: 38px; height: 38px; flex: 0 0 38px; place-items: center; color: var(--teal); background: var(--success-soft); border: 1px solid #b3dfd4; border-radius: 11px; font-size: 20px; }
.metric-value { flex: 0 0 auto; color: var(--navy-800); font-family: var(--font-mono); font-size: 31px; font-weight: 700; letter-spacing: -.08em; }
.metric-value small { margin-left: 3px; color: var(--muted); font-size: 13px; font-weight: 500; letter-spacing: 0; }
.flight-metrics p { margin: 0; color: var(--muted); font-size: 11px; line-height: 1.4; }
.flight-metrics p strong { display: block; margin-top: 3px; color: var(--ink); font-size: 13px; font-weight: 700; }
.metric-link { position: absolute; top: 17px; right: 18px; display: grid; width: 27px; height: 27px; place-items: center; color: var(--primary); background: var(--primary-soft); border: 1px solid #afd3e7; border-radius: 50%; }

.flight-section { margin-top: 56px; }
.flight-section-head { display: flex; align-items: end; justify-content: space-between; gap: 24px; margin-bottom: 19px; }
.flight-section-head h3 { margin: 5px 0 0; color: var(--ink); font-size: clamp(24px, 3vw, 34px); letter-spacing: -.04em; line-height: 1.2; }
.flight-section-head > p, .flight-section-head > span { max-width: 420px; margin: 0 0 3px; color: var(--text-secondary); font-size: 13px; line-height: 1.6; text-align: right; }
.simulation-tag { padding: 7px 11px; color: #17756b; background: var(--success-soft); border: 1px solid #acded3; border-radius: 999px; font-size: 11px; white-space: nowrap; }
.simulation-tag:first-letter { color: var(--teal); }

/* 系统热点 */
.system-explorer { display: grid; grid-template-columns: minmax(0, 1.3fr) minmax(300px, .7fr); overflow: hidden; background: var(--surface); border: 1px solid var(--line); border-radius: 18px; box-shadow: var(--shadow-soft); }
.system-visual { position: relative; min-height: 420px; overflow: hidden; background: var(--navy-900); }
.system-visual::after { position: absolute; inset: 0; pointer-events: none; content: ""; background: linear-gradient(180deg, rgba(5, 18, 32, .02), rgba(5, 18, 32, .32)); }
.system-visual img { display: block; width: 100%; height: 100%; min-height: 420px; object-fit: cover; object-position: center; opacity: .92; }
.system-hotspot { position: absolute; z-index: 2; display: flex; align-items: center; gap: 7px; padding: 6px 10px 6px 6px; color: #eaf9fb; background: rgba(7, 29, 48, .88); border: 1px solid rgba(91, 204, 210, .68); border-radius: 9px; box-shadow: 0 7px 18px rgba(0, 0, 0, .24); font-size: 11px; font-weight: 700; transform: translate(-50%, -50%); transition: background-color .2s ease, border-color .2s ease, transform .2s ease; }
.system-hotspot:hover, .system-hotspot.is-selected { background: #0e7381; border-color: #89e3df; transform: translate(-50%, -50%) scale(1.04); }
.system-hotspot span { display: grid; width: 23px; height: 23px; place-items: center; color: var(--navy-950); background: var(--cyan); border-radius: 7px; font-family: var(--font-mono); font-size: 10px; }
.system-scale { position: absolute; right: 14px; bottom: 13px; z-index: 2; padding: 5px 8px; color: #cae2e8; background: rgba(2, 14, 25, .6); border-radius: 5px; font-family: var(--font-mono); font-size: 10px; }
.system-detail { display: flex; min-height: 420px; flex-direction: column; align-items: flex-start; justify-content: center; padding: 38px 34px; }
.system-detail .flight-overline { color: var(--teal); }
.system-detail h4 { margin: 11px 0 1px; color: var(--ink); font-size: 27px; letter-spacing: -.035em; }
.part-model { color: var(--primary-dark); font-family: var(--font-mono); font-size: 12px; }
.system-detail > p { margin: 18px 0 0; color: var(--text-secondary); font-size: 14px; line-height: 1.7; }
.part-check { width: 100%; margin-top: 23px; padding: 13px 15px; background: var(--surface-tint); border: 1px solid var(--line); border-left: 3px solid var(--teal); border-radius: 10px; }
.part-check strong { color: var(--ink); font-size: 12px; }
.part-check p { margin: 4px 0 0; color: var(--text-secondary); font-size: 12px; line-height: 1.55; }
.system-detail .button { margin-top: 22px; }

/* 三种教学模拟 */
.flight-lab { padding: 27px; background: rgba(255, 255, 255, .73); border: 1px solid var(--line); border-radius: 18px; box-shadow: var(--shadow-soft); }
.flight-lab .flight-section-head { margin-bottom: 14px; }
.lab-tabs { display: flex; flex-wrap: wrap; gap: 7px; margin-bottom: 17px; padding: 5px; background: var(--surface-tint); border: 1px solid var(--line); border-radius: 12px; }
.lab-tabs button { min-height: 37px; padding: 7px 14px; color: var(--text-secondary); background: transparent; border: 0; border-radius: 8px; font-size: 13px; font-weight: 700; }
.lab-tabs button:hover { color: var(--primary-dark); background: var(--primary-soft); }
.lab-tabs button.active { color: #fff; background: var(--navy-800); box-shadow: 0 4px 10px rgba(9, 33, 54, .18); }
.lab-grid { display: grid; grid-template-columns: minmax(0, 1.15fr) minmax(300px, .85fr); gap: 0; overflow: hidden; background: var(--surface); border: 1px solid var(--line); border-radius: 14px; }
.lab-visual { position: relative; min-height: 370px; overflow: hidden; color: #eaf8fb; background: linear-gradient(145deg, #081a2d, #0f3550); }
.lab-visual::before { position: absolute; inset: 0; pointer-events: none; content: ""; background-image: linear-gradient(rgba(109, 205, 217, .055) 1px, transparent 1px), linear-gradient(90deg, rgba(109, 205, 217, .055) 1px, transparent 1px); background-size: 24px 24px; }
.instrument-top { position: relative; z-index: 1; display: flex; align-items: center; justify-content: space-between; padding: 19px 22px 0; color: #8cb8c7; font-family: var(--font-mono); font-size: 10px; letter-spacing: .08em; }
.instrument-top span:last-child { color: #6ed8cf; }
.lab-controls { display: flex; min-width: 0; flex-direction: column; align-items: flex-start; padding: 28px 30px; background: var(--surface); }
.lab-controls h4 { margin: 7px 0 10px; color: var(--ink); font-size: 21px; letter-spacing: -.025em; line-height: 1.3; }
.lab-controls > p { margin: 0 0 17px; color: var(--text-secondary); font-size: 13px; line-height: 1.65; }
.lab-controls > label, .lab-controls fieldset > legend { width: 100%; margin-top: 13px; color: var(--ink); font-size: 12px; font-weight: 700; }
.lab-controls select { margin-top: 7px; }
.scenario-description { margin: 9px 0 0 !important; color: var(--muted) !important; font-size: 12px !important; }
.lab-controls fieldset { width: 100%; margin: 12px 0 0; padding: 0; border: 0; }
.lab-controls fieldset legend { margin-bottom: 9px; }
.lab-choice { display: flex; width: 100%; align-items: flex-start; gap: 8px; padding: 9px 10px; color: var(--text-secondary); background: var(--surface-tint); border: 1px solid transparent; border-radius: 9px; font-size: 12px; line-height: 1.45; cursor: pointer; }
.lab-choice + .lab-choice { margin-top: 6px; }
.lab-choice:hover { border-color: #abd3e9; }
.lab-choice input { flex: 0 0 auto; margin-top: 3px; accent-color: var(--primary); }
.lab-controls > .button { width: 100%; margin-top: 17px; }
.lab-feedback { width: 100%; margin-top: 13px; padding: 12px 13px; color: #176b5d; background: var(--success-soft); border: 1px solid #a4d9ce; border-radius: 10px; font-size: 12px; line-height: 1.55; }
.lab-feedback:empty { display: none; }
.lab-feedback strong { display: block; color: inherit; font-size: 13px; }
.lab-feedback p { margin: 4px 0 0; }
.lab-feedback small { display: block; margin-top: 7px; color: #438378; }
.lab-footnote { margin: 15px 2px 0; color: var(--muted); font-family: var(--font-mono); font-size: 10px; line-height: 1.55; }

/* 供电链路概念图 */
.power-visual { display: flex; flex-direction: column; }
.power-diagram { position: relative; z-index: 1; display: flex; min-width: 0; flex: 0 1 auto; flex-direction: column; gap: 10px; padding: 15px 22px 17px; }
.power-diagram-label { margin: 0; color: #c5e6eb; font-size: 14px; line-height: 1.4; }
.power-chain { display: grid; min-width: 0; grid-template-columns: minmax(0, 1fr) minmax(24px, auto) minmax(0, 1fr) minmax(24px, auto) minmax(0, 1fr); align-items: center; gap: 0; }
.power-relation-row { display: grid; width: min(100%, 430px); min-width: 0; margin: 0 auto; grid-template-columns: minmax(0, 1fr) minmax(24px, auto) minmax(0, 1fr); align-items: center; gap: 0; }
.power-node { display: flex; width: 100%; min-width: 0; min-height: 88px; flex-direction: column; align-items: center; justify-content: center; gap: 7px; padding: 9px 7px; background: rgba(12, 47, 72, .84); border: 1px solid rgba(109, 205, 217, .48); border-radius: 14px; box-shadow: inset 0 1px 0 rgba(255, 255, 255, .08), 0 9px 18px rgba(0, 0, 0, .16); text-align: center; }
.power-node strong { color: var(--cyan); font-family: var(--font-mono); font-size: 18px; }
.power-node span { color: #c7dce5; font-size: 11px; line-height: 1.35; }
.power-node small { color: #85adbc; font-size: 9px; line-height: 1.35; }
.power-node.fault-node { background: rgba(137, 52, 59, .44); border-color: #ec8e8e; }
.power-node.fault-node strong { color: #ffb1ad; }
.power-edge { display: block; width: auto; min-width: 24px; color: var(--cyan); font-family: var(--font-mono); font-size: 25px; line-height: 1; text-align: center; }
.power-edge.broken { color: #ff8a83; text-shadow: 0 0 14px rgba(255, 116, 110, .3); }
.power-ground { position: relative; z-index: 1; display: grid; width: 100%; min-width: 0; grid-template-columns: auto minmax(0, 1fr) minmax(0, 1.2fr); align-items: center; gap: 9px; margin: 0; padding: 9px 12px; color: #96c9ce; background: rgba(8, 33, 53, .8); border: 1px dashed rgba(90, 206, 200, .47); border-radius: 9px; font-family: var(--font-mono); font-size: 11px; line-height: 1.45; }
.power-ground-mark { display: block; width: auto; min-width: 45px; height: auto; color: var(--teal); border: 0; border-radius: 0; box-shadow: none; white-space: nowrap; }
.power-ground > span:not(.power-ground-mark) { display: block; width: auto; min-width: 0; height: auto; color: #96c9ce; border: 0; border-radius: 0; box-shadow: none; }
.power-ground small { min-width: 0; color: #6f9cab; font-size: 9px; line-height: 1.4; }
.power-ground.is-fault { color: #ffb2ae; background: rgba(117, 42, 48, .55); border-color: rgba(255, 138, 131, .75); }
.power-ground.is-fault .power-ground-mark { color: #ffaaa5; font-size: 0; }
.power-ground.is-fault .power-ground-mark::after { content: "GND ×"; font-size: 10px; }
.power-ground.is-fault > span:not(.power-ground-mark) { color: #ffb2ae; }
.power-ground.is-fault small { color: #e39a98; }
.power-bypass-path { display: grid; width: 100%; min-width: 0; grid-template-columns: minmax(0, 1fr) minmax(0, 1.15fr); align-items: center; gap: 10px; margin: 0; padding: 9px 12px; color: #d5b1b0; background: rgba(71, 32, 44, .62); border: 1px dashed rgba(216, 123, 126, .48); border-radius: 9px; font-family: var(--font-mono); font-size: 10px; line-height: 1.45; }
.power-bypass-path span { min-width: 0; color: #efb4b1; }
.power-bypass-path small { min-width: 0; color: #c99393; font-size: 9px; line-height: 1.4; }
.power-bypass-path.is-preview { background: rgba(70, 53, 34, .56); border-color: rgba(230, 182, 74, .58); }
.power-bypass-path.is-preview span, .power-bypass-path.is-preview small { color: #e6c87a; }
.power-bypass-path.is-error { background: rgba(117, 42, 48, .55); border-color: rgba(255, 138, 131, .7); }
.power-bypass-path.is-error span, .power-bypass-path.is-error small { color: #ffaaa5; }
.power-legend { margin: 0; color: #709bab; font-family: var(--font-mono); font-size: 9px; line-height: 1.4; text-align: right; }
.instrument-note { position: relative; z-index: 1; display: flex; margin: auto 22px 20px; align-items: center; justify-content: space-between; gap: 12px; padding: 11px 13px; color: #d6ebef; background: rgba(6, 24, 40, .78); border: 1px solid rgba(114, 183, 198, .22); border-radius: 10px; }
.instrument-note strong { color: #bde6e6; font-size: 12px; }
.instrument-note span { color: #83aebd; font-family: var(--font-mono); font-size: 10px; }

/* CSS 人工地平仪 */
.attitude-visual { display: flex; flex-direction: column; }
.horizon { position: relative; width: min(270px, 73%); aspect-ratio: 1; margin: 24px auto 15px; overflow: hidden; background: #143a56; border: 2px solid rgba(149, 220, 226, .68); border-radius: 50%; box-shadow: 0 0 0 8px rgba(9, 40, 62, .65), 0 14px 32px rgba(0, 0, 0, .25); }
.horizon-world { position: absolute; inset: -35%; overflow: hidden; transition: transform .16s ease-out; }
.horizon-sky, .horizon-earth { position: absolute; right: 0; left: 0; height: 50%; }
.horizon-sky { top: 0; background: linear-gradient(180deg, #1d6584 0%, #75cbd0 100%); }
.horizon-earth { bottom: 0; background: linear-gradient(180deg, #537477 0%, #243d4c 100%); }
.horizon-grid { position: absolute; inset: 0; display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 16px; border: 0; }
.horizon-grid span { display: block; margin: 0; color: rgba(237, 255, 255, .8); font-family: var(--font-mono); font-size: 9px; line-height: 1; text-align: center; }
.horizon-reference { position: absolute; top: 50%; left: 50%; z-index: 3; display: block; width: max-content; color: #ffd36a; font-family: var(--font-mono); font-size: 24px; letter-spacing: 24px; line-height: 1; white-space: nowrap; transform: translate(-50%, -62%); }
.horizon-cross { position: absolute; top: 50%; left: 50%; z-index: 4; width: 92px; height: 2px; background: #ffd36a; box-shadow: 0 0 0 1px rgba(6, 29, 42, .32); transform: translate(-50%, -50%); }
.horizon-cross::before { position: absolute; left: 50%; width: 2px; height: 22px; content: ""; background: #ffd36a; transform: translateX(-50%); }
.attitude-values { position: relative; z-index: 2; display: flex; justify-content: center; gap: 33px; padding-bottom: 22px; }
.attitude-values > div { color: #84aabd; font-family: var(--font-mono); font-size: 10px; text-align: center; }
.attitude-values strong { display: block; margin-top: 3px; color: #d9f2f0; font-size: 17px; }
.lab-controls input[type="range"] { width: 100%; margin: 8px 0 8px; accent-color: var(--teal); }
.lab-controls > label small { float: right; color: var(--muted); font-size: 11px; font-weight: 400; }
.lab-controls > .button.button-ghost { width: auto; }

/* CSS 故障诊断卡 */
.fault-visual { padding-bottom: 24px; }
.fault-code { position: relative; z-index: 1; display: inline-block; margin: 34px 25px 0; padding: 5px 8px; color: #071d31; background: var(--cyan); border-radius: 6px; font-family: var(--font-mono); font-size: 10px; font-weight: 800; }
.fault-visual h4 { position: relative; z-index: 1; margin: 13px 25px 0; color: #fff; font-size: clamp(23px, 3vw, 32px); letter-spacing: -.04em; line-height: 1.17; }
.channel-bars { position: relative; z-index: 1; display: grid; gap: 11px; margin: 29px 25px 0; }
.channel-bars > div { display: grid; grid-template-columns: 44px minmax(0, 1fr) 44px; align-items: center; gap: 10px; color: #9fc2ce; font-family: var(--font-mono); font-size: 10px; }
.channel-bars i { display: block; height: 8px; overflow: hidden; background: #183c55; border: 1px solid rgba(112, 190, 204, .2); border-radius: 999px; }
.channel-bars b { display: block; width: 24%; height: 100%; background: #5ebac0; border-radius: inherit; opacity: .45; }
.channel-bars small { color: #da9696; font-size: 9px; }
.fault-visual > p { position: relative; z-index: 1; margin: 26px 25px 0; color: #94b3c0; font-size: 12px; line-height: 1.7; }

/* 学习路径与记录 */
.flight-journey { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 12px; }
.journey-card { position: relative; display: flex; min-height: 138px; flex-direction: column; align-items: flex-start; padding: 17px; color: var(--ink); background: var(--surface); border: 1px solid var(--line); border-radius: 14px; box-shadow: var(--shadow-soft); text-align: left; transition: border-color .2s ease, transform .2s ease, box-shadow .2s ease; }
.journey-card:hover { border-color: #74b9d6; box-shadow: 0 12px 25px rgba(16, 66, 93, .11); transform: translateY(-2px); }
.journey-card.is-complete { background: #f1fbf8; border-color: #a0d8cb; }
.journey-number { display: grid; width: 34px; height: 34px; place-items: center; color: #fff; background: var(--navy-800); border-radius: 10px; font-family: var(--font-mono); font-size: 12px; font-weight: 700; }
.journey-card.is-complete .journey-number { background: var(--teal); }
.journey-title { margin-top: 16px; color: var(--ink); font-size: 15px; font-weight: 700; }
.journey-card small { margin-top: 4px; color: var(--muted); font-size: 11px; line-height: 1.4; }
.journey-arrow { position: absolute; right: 16px; top: 16px; color: var(--primary); font-size: 17px; }
.flight-route { display: grid; grid-template-columns: .9fr 1.1fr; gap: 28px; margin-top: 20px; padding: 25px 28px; color: #d9edf1; background: var(--navy-850); border: 1px solid #1b4b68; border-radius: 15px; box-shadow: var(--shadow-dark); }
.flight-route h3 { margin: 5px 0 0; color: #fff; font-size: 20px; }
.flight-route p { margin: 0; color: #b5d0da; font-size: 13px; line-height: 1.8; }
.flight-route strong { color: var(--cyan); font-family: var(--font-mono); font-size: 11px; letter-spacing: .05em; }
.flight-route .flight-muted { grid-column: 2; color: #7fa1b0; font-size: 11px; }
.path-panel { padding: 26px; }
.learning-path, .result-path { gap: 10px; }
.path-step-button { min-height: 84px; align-items: center; padding: 12px; background: var(--surface-tint); border-color: var(--line); border-radius: 12px; }
.path-step-button:hover { background: var(--primary-soft); border-color: #82bddb; }
.path-step.is-current .path-step-button { padding: 11px; border-color: var(--primary); background: var(--primary-soft); }
.path-step:not(:last-child)::after { top: 29px; right: -8px; color: var(--muted); }
.path-number { width: 31px; height: 31px; flex-basis: 31px; border-radius: 9px; background: var(--navy-800); }
.path-step.is-current .path-number { background: var(--primary); }
.path-step.good .path-number, .result-path-item.good .path-number { background: var(--teal); }
.path-copy strong { font-size: 13px; }
.path-copy small { font-size: 11px; }
.path-checkpoint { border-radius: 10px; }
.home-command { border-left-color: var(--teal); }

/* 检查点、结果、锁定页 */
.checkpoint-bar { gap: 18px; margin-top: 25px; padding: 20px; background: var(--primary-soft); border-color: #a9d3e9; border-left: 4px solid var(--primary); border-radius: 14px; }
.checkpoint-bar.good { background: var(--success-soft); border-color: #9ad6c7; border-left-color: var(--teal); }
.checkpoint-bar.danger { background: var(--danger-soft); border-color: #e6a0a4; border-left-color: var(--danger); }
.checkpoint-marker { width: 49px; height: 49px; border-radius: 12px; background: var(--primary); }
.checkpoint-bar.good .checkpoint-marker { background: var(--teal); }
.checkpoint-copy h3 { font-size: 18px; }
.checkpoint-copy p, .checkpoint-meta p { color: var(--text-secondary); }
.checkpoint-meta { border-left-color: #b0cddd; }
.report-grid { grid-template-columns: 1.12fr .88fr; }
.score-board { padding: 28px; background: var(--navy-850); border-color: var(--navy-700); border-radius: 16px; box-shadow: var(--shadow-dark); }
.score-board p { color: #a9c4d1; }
.score-total { color: var(--cyan); font-size: 62px; }
.score-total small { color: #a8c6d3; }
.score-board .evidence-list li { color: #c2d9e2; border-bottom-color: rgba(157, 203, 219, .18); }
.score-board .evidence-list li b { color: #fff; }
.locked-state { max-width: 820px; padding: 20px 0; }
.locked-mark { width: 44px; height: 44px; border-radius: 12px; background: var(--navy-800); }
.locked-state h3 { font-size: 21px; }
.locked-state p, .locked-state ol { color: var(--text-secondary); }
.empty-state { padding: 42px; }
.toast { right: 24px; bottom: 24px; padding: 13px 17px; background: var(--navy-850); border: 1px solid #2c5b74; border-radius: 11px; box-shadow: var(--shadow-dark); }
.dialog { border-radius: 16px; }

/* 装配、地面站和诊断页 */
.assembly-stage, .assembly-parts { padding: 23px; }
.assembly-stage-head h3, .assembly-parts-head h3 { font-size: 19px; }
.assembly-stage-head p, .assembly-parts-head p { color: var(--text-secondary); }
.assembly-pending { color: var(--primary-dark); background: var(--primary-soft); border-color: #a7d3e9; border-radius: 10px; }
.assembly-svg { background: #f8fbfc; border-color: var(--line); border-radius: 13px; }
.asm-arm { stroke: #c5d2da; }
.asm-plate { fill: var(--navy-850); stroke: var(--primary); }
.asm-plate-label { fill: #9fc5d3; }
.asm-pos-label, .asm-slot-label { fill: var(--text-secondary); }
.asm-slot-base { fill: #fff; stroke: var(--line-strong); }
.asm-motor-bell { fill: #eef4f6; stroke: #94aab8; }
.assembly-frame { padding: 10px; background: #f8fbfc; border-color: var(--line); border-radius: 12px; }
.part-button { padding: 12px; background: var(--surface-tint); border-color: var(--line); border-radius: 11px; }
.part-button:hover, .part-button.is-selected { background: var(--primary-soft); border-color: #7fbddd; }
.part-button.is-selected { box-shadow: inset 0 0 0 1px var(--primary); }
.gs-statusbar { padding: 11px 13px; background: var(--surface-tint); border-color: var(--line); border-radius: 11px; }
.gs-status { border-radius: 999px; }
.gs-step { border-color: var(--line); border-radius: 11px; }
.gs-step:hover, .gs-step.is-next { background: var(--primary-soft); border-color: #82bddb; }
.gs-step-num { border-radius: 9px; background: var(--navy-800); }
.gs-step.is-done .gs-step-num { background: var(--teal); }
.gs-log { border-radius: 11px; }
.diagnosis-step { padding: 20px; border-color: var(--line); border-radius: 14px; box-shadow: var(--shadow-soft); }
.tab-button { border-radius: 9px; }
.tab-button:hover, .tab-button.is-active { background: var(--navy-800); border-color: var(--navy-800); }
.quiz-card { padding: 28px; }
.quiz-card h3 { font-size: 22px; }

/* 专注阅读：保留顶部退出入口，扩大正文阅读宽度 */
body.reading-focus .sidebar { display: none; }
body.reading-focus .app-shell { display: block; }
body.reading-focus .main-content { max-width: 1260px; margin: 0 auto; }
body.reading-focus .flight-hero { min-height: 560px; }

/* 平板与移动端 */
@media (max-width: 1120px) {
  .app-shell { grid-template-columns: 274px minmax(0, 1fr); }
  .main-content { padding-right: 28px; padding-left: 28px; }
  .flight-hero-copy { width: 61%; padding-right: 36px; padding-left: 36px; }
  .system-explorer { grid-template-columns: minmax(0, 1fr) 320px; }
  .flight-journey { grid-template-columns: repeat(4, minmax(0, 1fr)); }
}

@media (max-width: 820px) {
  .topbar { min-height: 64px; padding: 9px 16px; }
  .topbar-actions { gap: 8px; }
  .topbar-context { max-width: 150px; }
  .sidebar { position: static; height: auto; padding: 18px 16px; border-right: 0; border-bottom: 1px solid rgba(130, 194, 219, .17); }
  .app-shell { display: block; min-height: 0; }
  .course-meta { padding: 0 8px 16px; }
  .course-meta p:not(.eyebrow) { display: none; }
  .mobile-nav-shell { margin-top: 13px; }
  .mobile-nav-summary { color: #e6f5f7; background: rgba(29, 91, 113, .32); border-color: rgba(91, 199, 212, .32); border-left-color: var(--cyan); border-radius: 10px; }
  .nav-group { padding-top: 16px; }
  .nav-group + .nav-group { margin-top: 3px; }
  .nav-button { min-height: 49px; }
  .main-content { padding: 20px 16px 50px; }
  .safety-strip { margin-bottom: 20px; }
  .page-heading { gap: 18px; }
  .page-heading h2 { font-size: 31px; }
  .system-explorer, .lab-grid, .flight-route { grid-template-columns: 1fr; }
  .system-visual { min-height: 360px; }
  .system-visual img { min-height: 360px; }
  .system-detail { min-height: 0; padding: 28px; }
  .lab-controls { padding: 25px 24px; }
  .flight-route .flight-muted { grid-column: auto; }
  .flight-journey { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .flight-hero { min-height: 580px; }
  .flight-hero-copy { width: 72%; min-height: 580px; padding: 42px 30px; }
  .flight-hero h2 { font-size: clamp(36px, 7vw, 52px); }
  .flight-metrics { grid-template-columns: 1fr; }
  .flight-metrics > div { min-height: 82px; padding: 15px 18px; }
  .flight-metrics > div + div { border-top: 1px solid var(--line); border-left: 0; }
  .power-diagram { padding-right: 16px; padding-left: 16px; }
  .power-chain { grid-template-columns: minmax(0, 1fr) minmax(22px, auto) minmax(0, 1fr) minmax(22px, auto) minmax(0, 1fr); }
  .power-node { width: 100%; min-height: 78px; }
  .power-edge { width: auto; min-width: 22px; }
}

@media (max-width: 560px) {
  .topbar { align-items: center; gap: 7px; }
  .brand strong { font-size: 14px; }
  .brand small, .offline-badge, .topbar-context { display: none; }
  .brand-mark { width: 34px; height: 34px; }
  .button-quiet { padding: 7px 10px; font-size: 11px; }
  .main-content { padding-right: 12px; padding-left: 12px; }
  .safety-strip { margin-right: 0; margin-left: 0; padding: 11px 12px; font-size: 12px; }
  .flight-breadcrumb { align-items: flex-start; flex-direction: column; gap: 3px; margin-right: 2px; margin-left: 2px; font-size: 10px; }
  .flight-hero { min-height: 590px; border-radius: 17px; }
  .flight-hero::before { background: linear-gradient(180deg, rgba(4, 18, 33, .78) 0%, rgba(4, 18, 33, .96) 72%, rgba(4, 18, 33, .98)); }
  .flight-hero-copy { width: 100%; min-height: 590px; justify-content: flex-start; padding: 42px 24px 28px; }
  .flight-hero-image { height: 62%; object-position: 57% top; opacity: .62; }
  .flight-hero h2 { margin-top: 12px; font-size: 39px; }
  .flight-hero-copy > p:not(.flight-hero-label) { margin-top: 18px; font-size: 14px; }
  .flight-hero .button-row { width: 100%; flex-direction: column; margin-top: 23px; }
  .flight-hero .button-row .button { width: 100%; }
  .flight-hero-foot { margin-top: auto; font-size: 9px; }
  .flight-image-caption { right: 11px; bottom: 9px; font-size: 9px; }
  .flight-section { margin-top: 40px; }
  .flight-section-head { display: block; }
  .flight-section-head h3 { font-size: 27px; }
  .flight-section-head > p, .flight-section-head > span { margin-top: 9px; text-align: left; }
  .flight-lab { padding: 17px 13px; border-radius: 14px; }
  .lab-tabs { overflow-x: auto; flex-wrap: nowrap; }
  .lab-tabs button { flex: 1 0 auto; }
  .lab-grid { border-radius: 11px; }
  .lab-visual { min-height: 340px; }
  .lab-controls { padding: 22px 17px; }
  .lab-controls h4 { font-size: 19px; }
  .instrument-top { padding-right: 14px; padding-left: 14px; font-size: 9px; }
  .power-diagram { gap: 9px; padding: 13px 12px 15px; }
  .power-chain { min-height: 0; padding: 0; grid-template-columns: minmax(0, 1fr) minmax(18px, auto) minmax(0, 1fr) minmax(18px, auto) minmax(0, 1fr); }
  .power-relation-row { width: 100%; grid-template-columns: minmax(0, 1fr) minmax(18px, auto) minmax(0, 1fr); }
  .power-node { width: 100%; min-height: 76px; }
  .power-node strong { font-size: 15px; }
  .power-node span { font-size: 10px; }
  .power-node small { font-size: 8px; }
  .power-edge { width: auto; min-width: 18px; font-size: 19px; }
  .power-ground { grid-template-columns: auto minmax(0, 1fr); font-size: 9px; }
  .power-ground small { grid-column: 2; }
  .power-bypass-path { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 7px; }
  .power-legend { text-align: left; }
  .instrument-note { display: block; margin-right: 14px; margin-left: 14px; }
  .instrument-note span { display: block; margin-top: 4px; }
  .horizon { width: 220px; }
  .attitude-values { gap: 19px; }
  .attitude-values strong { font-size: 15px; }
  .flight-journey { grid-template-columns: 1fr 1fr; gap: 8px; }
  .journey-card { min-height: 131px; padding: 13px; }
  .journey-title { margin-top: 11px; font-size: 13px; }
  .journey-card small { font-size: 10px; }
  .flight-route { gap: 16px; padding: 20px 18px; }
  .flight-route h3 { font-size: 18px; }
  .card-pad, .quiz-card, .path-panel { padding: 18px; }
  .page-heading h2 { font-size: 27px; }
  .page-description { font-size: 14px; }
  .page-context { grid-template-columns: 1fr; }
  .page-context > div { border-right: 0; }
  .task-guide { grid-template-columns: 1fr; gap: 8px; }
  .guide-card { min-height: 0; padding: 15px; }
  .checkpoint-bar { grid-template-columns: 1fr; padding: 17px; }
  .checkpoint-meta { grid-column: auto; padding: 12px 0 0; border-top: 1px solid var(--line); border-left: 0; }
  .report-grid { grid-template-columns: 1fr; }
  .score-total { font-size: 52px; }
  .assembly-stage, .assembly-parts { padding: 15px; }
  .assembly-parts-grid, .part-grid { grid-template-columns: 1fr 1fr; }
  .tabs { overflow-x: auto; }
  .quiz-pagination { align-items: stretch; flex-direction: column; }
  .quiz-pagination .button { width: 100%; }
  body.reading-focus .main-content { padding-right: 12px; padding-left: 12px; }
}

@media print {
  :root { --workbench: #fff; --line: #b8b8b8; }
  html, body { background: #fff; }
  body::before, .topbar, .sidebar, .safety-strip, .button, .flight-hero-foot, .metric-link, .lab-tabs, .flight-footnote { display: none !important; }
  .app-shell { display: block; }
  .main-content { padding: 0; }
  .learning-page { max-width: none; }
  .flight-hero { min-height: 320px; box-shadow: none; print-color-adjust: exact; }
  .flight-hero-copy { min-height: 320px; padding: 30px; }
  .flight-hero h2 { font-size: 38px; }
  .flight-hero-image { opacity: .55; }
  .flight-metrics, .card, .flight-section, .flight-route { break-inside: avoid; box-shadow: none; }
  .flight-section { margin-top: 26px; }
  .flight-lab { padding: 18px; }
  a { color: inherit; text-decoration: none; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; animation-duration: .01ms !important; animation-iteration-count: 1 !important; transition-duration: .01ms !important; }
  .button:hover, .journey-card:hover, .system-hotspot:hover, .system-hotspot.is-selected { transform: none; }
}

/* P14 清爽简洁层：浅白阅读区，蓝绿只承担行动与状态。 */
:root {
  --navy-950: #102d43;
  --navy-900: #173d54;
  --navy-850: #1c4961;
  --navy-800: #21536b;
  --navy-700: #2a687f;
  --navy-600: #347f96;
  --primary: #1477b8;
  --primary-dark: #0b5f94;
  --primary-soft: #eaf5fb;
  --teal: #0b8f83;
  --cyan: #2aa8ae;
  --ink: #173449;
  --text-secondary: #536b7c;
  --muted: #758d9b;
  --workbench: #f5f9fa;
  --surface: #ffffff;
  --surface-tint: #f7fbfc;
  --line: #d8e5e9;
  --line-strong: #b7cbd2;
  --success: #0b8f7e;
  --success-soft: #e8f7f2;
  --warning: #9a6800;
  --warning-bg: #fff8e3;
  --warning-line: #e3bc55;
  --danger: #c4474f;
  --danger-soft: #fff1f2;
  --danger-line: #e39a9f;
  --neutral-soft: #eef3f5;
  --shadow-soft: 0 5px 18px rgba(28, 72, 94, .06);
  --shadow-card: 0 10px 28px rgba(28, 72, 94, .08);
  --shadow-dark: 0 14px 30px rgba(20, 57, 75, .16);
}

html, body { background: var(--workbench); }
body { color: var(--ink); }
body::before { background-image: radial-gradient(circle at 15% 0%, rgba(42, 168, 174, .08), transparent 34%); background-size: auto; mask-image: none; }
.sr-only { position: absolute !important; width: 1px !important; height: 1px !important; padding: 0 !important; overflow: hidden !important; clip: rect(0, 0, 0, 0) !important; white-space: nowrap !important; border: 0 !important; }

/* 顶栏只保留教材名、当前位置和两个必要动作。 */
.topbar { min-height: 64px; padding: 10px clamp(16px, 3vw, 34px); color: var(--ink); background: rgba(255, 255, 255, .96); border-bottom: 1px solid var(--line); box-shadow: 0 4px 16px rgba(28, 72, 94, .07); backdrop-filter: blur(12px); }
.topbar::after { display: none; }
.brand { display: flex; min-width: 0; align-items: center; gap: 10px; }
.brand-mark { display: grid; width: 34px; height: 34px; flex: 0 0 34px; place-items: center; color: var(--primary); background: #eef8fa; border: 1px solid #b8dfe2; border-radius: 10px; box-shadow: none; font-size: 0; }
.brand-mark::after { display: none; }
.brand-mark svg { width: 20px; height: 20px; fill: none; stroke: currentColor; stroke-linecap: round; stroke-linejoin: round; stroke-width: 1.5; }
.brand strong { overflow: hidden; color: var(--ink); font-size: 15px; font-weight: 700; letter-spacing: .01em; text-overflow: ellipsis; white-space: nowrap; }
.topbar-actions { display: flex; min-width: 0; align-items: center; gap: 8px; }
.topbar-context { max-width: 270px; overflow: hidden; color: var(--muted); font-size: 12px; text-overflow: ellipsis; white-space: nowrap; }
.icon-button { display: inline-grid; width: 40px; min-height: 40px; padding: 8px; place-items: center; color: var(--primary-dark); background: #f6fafb; border: 1px solid var(--line); border-radius: 10px; box-shadow: none; }
.icon-button:hover { color: var(--teal); background: #edf8f8; border-color: #a8d4d4; box-shadow: none; transform: none; }
.icon-button svg { width: 18px; height: 18px; fill: none; stroke: currentColor; stroke-linecap: round; stroke-linejoin: round; stroke-width: 1.6; }

/* 侧栏缩窄，状态仍保留文字。 */
.app-shell { grid-template-columns: 236px minmax(0, 1fr); min-height: calc(100vh - 64px); }
.sidebar { top: 64px; height: calc(100vh - 64px); padding: 22px 12px 26px; color: var(--ink); background: #f8fcfc; border-right: 1px solid var(--line); box-shadow: 3px 0 16px rgba(28, 72, 94, .025); scrollbar-color: #b6d1d5 transparent; }
.sidebar::before { display: none; }
.course-meta { padding: 0 8px 17px; border-bottom: 1px solid var(--line); }
.eyebrow { margin: 0 0 6px; color: var(--teal); font-family: var(--font-mono); font-size: 10px; letter-spacing: .1em; }
.course-meta h1 { color: var(--ink); font-size: 17px; line-height: 1.35; }
.course-meta p:not(.eyebrow) { margin-top: 7px; color: var(--muted); font-size: 11px; }
.nav-group { padding-top: 17px; }
.nav-group + .nav-group { margin-top: 7px; border-top: 1px solid var(--line); }
.nav-section-heading, .panel-heading { padding: 0 8px; }
.nav-section-heading h2, .panel-heading h2 { color: var(--ink); font-size: 12px; }
.nav-section-heading span, .panel-heading span { color: var(--teal); font-size: 10px; }
.course-nav, .result-nav { gap: 4px; padding-top: 8px; }
.nav-button { min-height: 44px; gap: 8px; padding: 7px 8px; color: #506a79; border-color: transparent; border-radius: 9px; }
.nav-button:hover { color: var(--ink); background: #eef7f8; border-color: #d5e8eb; }
.nav-button.is-active { color: var(--ink); background: #e8f5f6; border-color: #b8dfe0; border-left: 3px solid var(--teal); padding-left: 6px; box-shadow: none; }
.nav-number { color: #8aa1ad; font-size: 11px; }
.nav-button.is-active .nav-number { color: var(--teal); }
.nav-copy strong { font-size: 12px; }
.nav-copy small { color: #8499a5; font-size: 10px; }
.nav-button.is-active .nav-copy small, .nav-button.good .nav-copy small { color: var(--teal); }
.nav-checkpoint, .gate-id { min-width: 27px; height: 20px; color: var(--teal); background: #e5f5f3; border: 1px solid #a9d9d2; border-radius: 6px; font-size: 9px; }
.gate-list { gap: 6px; margin-top: 9px; }
.gate-card { padding: 9px; background: #fff; border-color: var(--line); border-left-width: 3px; border-radius: 9px; box-shadow: none; }
.gate-card.good { background: var(--success-soft); border-left-color: var(--teal); }
.gate-card.active { border-left-color: var(--primary); }
.gate-card.danger { border-left-color: var(--danger); }
.gate-card h3 { color: var(--ink); font-size: 11px; }
.gate-card p, .section-helper { color: var(--muted); font-size: 10px; }
.status-token { color: var(--muted); background: #f3f7f8; border-color: var(--line); font-size: 10px; }
.status-token.good, .status-chip.good { color: #167165; background: var(--success-soft); border-color: #a9d9d0; }
.status-token.warn, .status-chip.warn { color: #875c05; background: var(--warning-bg); border-color: #e6c977; }
.progress-panel { margin-top: 17px; padding: 14px 8px 0; border-top: 1px solid var(--line); }
.progress-panel-heading { color: var(--muted); font-size: 11px; }
.progress-panel-heading strong { color: var(--ink); font-size: 10px; }
.progress-track { height: 6px; margin-top: 8px; background: #e1ecef; border-radius: 99px; }
.progress-fill { background: linear-gradient(90deg, var(--teal), #4fb9b1); }
.progress-panel p { color: var(--muted); font-size: 10px; }

/* 阅读区与正文页面。 */
.main-content { max-width: 1360px; padding: 26px clamp(18px, 3.7vw, 56px) 60px; }
.learning-page { max-width: 1180px; }
.safety-strip { max-width: 1180px; min-height: 43px; margin-bottom: 18px; padding: 10px 13px; color: #76570e; background: #fff9e8; border-color: #eed27f; border-left-width: 3px; border-radius: 10px; box-shadow: none; font-size: 12px; }
.safety-strip strong { color: #5a4005; }
.card { background: rgba(255, 255, 255, .98); border-color: var(--line); border-radius: 13px; box-shadow: var(--shadow-soft); }
.card-pad { padding: 22px; }
.section-gap { margin-top: 20px; }
.page-heading { gap: 24px; margin-bottom: 22px; }
.page-heading h2 { font-size: clamp(25px, 3vw, 36px); }
.page-description { margin-top: 10px; color: var(--text-secondary); font-size: 14px; }
.page-context { border-color: var(--line); border-radius: 12px; box-shadow: none; }
.task-guide { gap: 9px; margin-bottom: 21px; }
.guide-card { min-height: 118px; padding: 15px; background: #fff; border-color: var(--line); border-top-width: 2px; border-radius: 11px; box-shadow: none; }
.guide-card h3 { font-size: 14px; }
.guide-card ul { font-size: 12px; }
.flight-guide { margin-bottom: 18px; background: #fff; border-color: var(--line); border-radius: 11px; }
.flight-guide summary { padding: 11px 14px; font-size: 12px; }
.button { min-height: 42px; padding: 9px 15px; border-radius: 9px; box-shadow: none; font-size: 13px; }
.button:hover { box-shadow: none; transform: translateY(-1px); }
.button-primary { background: var(--primary); }
.button-primary:hover { background: var(--primary-dark); }
.button-success { background: var(--teal); }
.button-success:hover { background: #08756c; }
.button-quiet { min-height: 40px; }
.button-ghost { color: var(--primary-dark); background: var(--primary-soft); border-color: #b7d9e8; }
.button-danger { background: var(--danger); }
.choice, .check-row, .quiz-option { min-height: 46px; padding: 11px 12px; border-color: var(--line); border-radius: 9px; }
.choice:hover, .check-row:hover, .quiz-option:hover { background: #f1f8fb; border-color: #96c5d7; }
.callout { padding: 14px 15px; border-radius: 10px; }
.feedback { border-radius: 10px; }
.form-field input, .form-field select, .form-field textarea, .motor-table select, .lab-controls select { padding: 10px 11px; border-color: var(--line-strong); border-radius: 8px; }
.checkpoint-bar { margin-top: 21px; padding: 17px; border-radius: 11px; }
.diagnosis-step { padding: 17px; border-color: var(--line); border-radius: 11px; box-shadow: none; }

/* 首页：只保留封面、恢复位置、进度和目录。 */
.flight-hero { min-height: 360px; border-color: #b9d8de; border-radius: 18px; box-shadow: var(--shadow-dark); }
.flight-hero::before { background: linear-gradient(96deg, rgba(7, 31, 49, .92) 0%, rgba(7, 31, 49, .73) 42%, rgba(7, 31, 49, .15) 85%); }
.flight-hero::after { display: none; }
.flight-hero-image { opacity: .96; object-position: center; }
.flight-hero-copy { width: min(56%, 580px); min-height: 360px; padding: 38px 42px; }
.flight-hero-label { margin-top: 0; color: #c7e9e9; font-size: 12px; letter-spacing: .04em; }
.flight-hero h2 { margin-top: 10px; font-size: clamp(34px, 4vw, 52px); letter-spacing: -.05em; }
.flight-hero-copy > p:not(.flight-hero-label) { max-width: 360px; margin-top: 17px; color: #d3e4e8; font-size: 14px; line-height: 1.7; }
.flight-hero-foot { margin-top: 29px; color: #b7d1d6; font-size: 10px; }
.flight-hero-foot i { display: none; }
.flight-image-caption { right: 14px; bottom: 13px; padding: 4px 7px; color: rgba(227, 244, 245, .84); background: rgba(7, 31, 49, .44); border-color: rgba(205, 237, 238, .28); font-size: 9px; }
.home-resume { display: grid; grid-template-columns: minmax(180px, .8fr) minmax(210px, 1fr) auto; gap: 20px; align-items: center; margin-top: 14px; padding: 16px 19px; background: #fff; border: 1px solid var(--line); border-radius: 13px; box-shadow: var(--shadow-soft); }
.home-resume-copy .section-kicker { margin: 0; color: var(--teal); font-size: 10px; }
.home-resume h3 { margin: 3px 0 0; color: var(--ink); font-size: 17px; }
.home-resume-copy > p:last-child { margin: 4px 0 0; color: var(--muted); font-size: 12px; }
.home-resume-copy strong { color: var(--ink); }
.home-progress { min-width: 0; }
.home-progress-label { display: flex; align-items: baseline; justify-content: space-between; color: var(--muted); font-family: var(--font-mono); font-size: 11px; }
.home-progress-label strong { color: var(--teal); font-size: 13px; }
.home-progress-track { height: 7px; margin-top: 7px; overflow: hidden; background: #e6eff1; border-radius: 99px; }
.home-progress-track span { display: block; height: 100%; background: linear-gradient(90deg, var(--primary), var(--teal)); border-radius: inherit; transition: width .2s ease; }
.home-progress > small { display: block; margin-top: 6px; color: var(--muted); font-size: 10px; }
.home-resume-action { min-width: 116px; }
.home-path { margin-top: 34px; }
.home-path .flight-section-head { margin-bottom: 13px; }
.home-path .flight-section-head h3 { font-size: 24px; }
.flight-journey { grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 9px; }
.journey-card { min-height: 105px; padding: 13px; background: #fff; border-color: var(--line); border-radius: 11px; box-shadow: none; }
.journey-card:hover { border-color: #9acbd3; background: #fbfefe; box-shadow: 0 6px 15px rgba(28, 72, 94, .07); }
.journey-card.is-complete { background: #effaf6; border-color: #b6ddd5; }
.journey-number { width: 29px; height: 29px; border-radius: 8px; background: #28566d; font-size: 11px; }
.journey-card.is-complete .journey-number { background: var(--teal); }
.journey-title { margin-top: 11px; font-size: 13px; }
.journey-card small { margin-top: 3px; color: var(--muted); font-size: 10px; }
.journey-arrow { right: 12px; top: 12px; color: var(--primary); font-size: 15px; }
.home-details { margin-top: 11px; background: #fff; border: 1px solid var(--line); border-radius: 11px; box-shadow: none; }
.home-details summary, .lab-boundary summary, .lab-details summary, .visual-details summary { display: flex; min-height: 48px; align-items: center; justify-content: space-between; gap: 14px; padding: 12px 15px; color: var(--ink); font-size: 12px; font-weight: 700; cursor: pointer; list-style: none; }
.home-details summary::-webkit-details-marker, .lab-boundary summary::-webkit-details-marker, .lab-details summary::-webkit-details-marker, .visual-details summary::-webkit-details-marker { display: none; }
.home-details summary::after, .lab-boundary summary::after, .lab-details summary::after, .visual-details summary::after { color: var(--teal); content: "+"; font-family: var(--font-mono); font-size: 16px; font-weight: 400; }
.home-details[open] > summary::after, .lab-boundary[open] > summary::after, .lab-details[open] > summary::after, .visual-details[open] > summary::after { content: "−"; }
.home-details summary small { color: var(--muted); font-size: 10px; font-weight: 400; }
.home-details-body { padding: 0 15px 16px; }
.home-details-body .flight-section-head { margin: 4px 0 13px; }
.home-details-body .flight-section-head h3 { font-size: 20px; }
.home-details-body .flight-section-head > p { font-size: 12px; }
.home-details .system-explorer { box-shadow: none; border-radius: 11px; }
.home-details .system-visual, .home-details .system-visual img { min-height: 300px; }
.home-details .system-detail { min-height: 300px; padding: 23px; }
.home-details .system-detail h4 { font-size: 22px; }
.home-route { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 9px 22px; color: var(--text-secondary); font-size: 12px; line-height: 1.6; }
.home-route p { margin: 0; }
.home-route strong { color: var(--primary-dark); font-family: var(--font-mono); font-size: 11px; }
.home-route .flight-muted { grid-column: 1 / -1; color: var(--muted); font-size: 11px; }

/* 章节实验：保留图形与操作，解释按需展开。 */
.flight-lab { padding: 20px; background: #fff; border-color: var(--line); border-radius: 13px; box-shadow: var(--shadow-soft); }
.flight-lab .flight-section-head { margin-bottom: 12px; }
.flight-lab .flight-section-head h3 { font-size: 23px; }
.simulation-tag { padding: 5px 9px; color: var(--teal); background: var(--success-soft); border-color: #b4ddd5; border-radius: 99px; font-size: 10px; }
.lab-tabs { gap: 5px; margin-bottom: 12px; padding: 4px; background: var(--surface-tint); border-color: var(--line); border-radius: 9px; }
.lab-tabs button { min-height: 34px; padding: 6px 11px; color: var(--muted); border-radius: 7px; font-size: 12px; }
.lab-tabs button.active { color: #fff; background: var(--teal); box-shadow: none; }
.lab-grid { border-color: var(--line); border-radius: 11px; }
.lab-visual { min-height: 345px; background: linear-gradient(145deg, #12374f, #1c5367); }
.lab-visual::before { opacity: .45; }
.instrument-top { padding: 15px 17px 0; font-size: 9px; }
.instrument-top span:last-child { color: #8ed6ce; }
.lab-controls { padding: 22px 23px; }
.lab-controls h4 { margin: 0 0 7px; font-size: 19px; }
.lab-controls > p.lab-lead { margin: 0 0 11px; color: var(--text-secondary); font-size: 12px; line-height: 1.55; }
.lab-controls > label, .lab-controls fieldset > legend { margin-top: 10px; font-size: 11px; }
.lab-controls select { margin-top: 6px; }
.lab-details, .visual-details { width: 100%; margin-top: 9px; background: #f7fbfc; border: 1px solid var(--line); border-radius: 8px; }
.lab-details summary, .visual-details summary { min-height: 37px; padding: 8px 10px; color: var(--text-secondary); font-size: 11px; }
.lab-details p, .visual-details p { margin: 0; padding: 0 10px 10px; color: var(--text-secondary); font-size: 11px; line-height: 1.55; }
.lab-choice { padding: 8px 9px; color: var(--text-secondary); background: #f8fbfc; border-color: transparent; border-radius: 8px; font-size: 11px; }
.lab-choice + .lab-choice { margin-top: 5px; }
.lab-controls > .button { width: 100%; margin-top: 13px; }
.lab-feedback { margin-top: 10px; padding: 10px 11px; border-radius: 8px; font-size: 11px; }
.lab-feedback strong { font-size: 12px; }
.lab-feedback p { margin: 3px 0 0; }
.lab-feedback small { margin-top: 5px; }
.lab-boundary { margin-top: 12px; background: #f7fbfc; border: 1px solid var(--line); border-radius: 9px; }
.lab-boundary summary { min-height: 40px; padding: 9px 11px; color: var(--text-secondary); font-size: 11px; }
.lab-boundary p { margin: 0; padding: 0 11px 11px; color: var(--text-secondary); font-size: 11px; line-height: 1.6; }
.lab-footnote { display: none; }
.instrument-note { margin: auto 16px 15px; padding: 9px 11px; border-color: rgba(154, 219, 219, .22); border-radius: 8px; }
.instrument-note strong { font-size: 11px; }
.instrument-note span { font-size: 9px; }
.power-diagram { gap: 8px; padding: 14px 17px 15px; }
.power-diagram-label { color: #c6e5e7; font-size: 12px; }
.power-node { min-height: 77px; gap: 5px; padding: 8px 6px; border-radius: 11px; }
.power-node strong { font-size: 16px; }
.power-node span { font-size: 10px; }
.power-node small { font-size: 8px; }
.power-edge { font-size: 21px; }
.power-ground { padding: 8px 10px; font-size: 10px; }
.power-ground small { font-size: 8px; }
.power-bypass-path { padding: 8px 10px; font-size: 9px; }
.power-bypass-path small { font-size: 8px; }
.power-legend { font-size: 8px; }
.horizon { width: min(246px, 70%); margin: 21px auto 12px; }
.attitude-values { gap: 26px; padding-bottom: 18px; }
.attitude-values strong { font-size: 15px; }
.fault-code { margin: 28px 20px 0; padding: 4px 7px; }
.fault-visual h4 { margin: 11px 20px 0; font-size: clamp(21px, 3vw, 29px); }
.channel-bars { gap: 9px; margin: 23px 20px 0; }
.fault-visual .visual-details { width: auto; margin: 20px 20px 0; background: rgba(8, 32, 48, .46); border-color: rgba(141, 204, 208, .22); }
.fault-visual .visual-details summary { color: #c8e5e7; }
.fault-visual .visual-details p { color: #9ec1ca; }
.part-check { margin-top: 14px; padding: 10px 11px; border-radius: 8px; }
.part-check p { font-size: 11px; }

@media (max-width: 1120px) {
  .app-shell { grid-template-columns: 220px minmax(0, 1fr); }
  .main-content { padding-right: 28px; padding-left: 28px; }
  .flight-hero-copy { width: 60%; padding-right: 32px; padding-left: 32px; }
}

@media (max-width: 820px) {
  .topbar { min-height: 60px; }
  .app-shell { display: block; min-height: 0; }
  .sidebar { position: static; height: auto; padding: 15px 16px; border-right: 0; border-bottom: 1px solid var(--line); box-shadow: none; }
  .course-meta { padding: 0 7px 13px; }
  .course-meta p:not(.eyebrow) { display: none; }
  .mobile-nav-shell { margin-top: 11px; }
  .mobile-nav-summary { color: var(--ink); background: #eef8f8; border-color: #c6e2e3; border-left-color: var(--teal); border-radius: 9px; }
  .nav-group { padding-top: 14px; }
  .nav-group + .nav-group { margin-top: 2px; }
  .main-content { padding: 18px 16px 45px; }
  .safety-strip { margin-bottom: 16px; }
  .home-resume { grid-template-columns: 1fr 1.2fr; gap: 14px; }
  .home-resume-action { grid-column: 1 / -1; width: 100%; }
  .flight-hero { min-height: 400px; }
  .flight-hero-copy { width: 72%; min-height: 400px; padding: 35px 27px; }
  .flight-hero h2 { font-size: clamp(34px, 7vw, 46px); }
  .flight-journey { grid-template-columns: repeat(4, minmax(0, 1fr)); }
  .system-explorer, .lab-grid { grid-template-columns: 1fr; }
  .system-visual, .system-visual img { min-height: 340px; }
  .system-detail { min-height: 0; padding: 24px; }
}

@media (max-width: 560px) {
  .brand strong { max-width: 220px; font-size: 13px; }
  .topbar-context { display: none; }
  .topbar-actions { margin-left: auto; }
  .main-content { padding-right: 12px; padding-left: 12px; }
  .safety-strip { align-items: flex-start; }
  .safety-strip strong { flex: 0 0 auto; white-space: nowrap; }
  .flight-hero { min-height: 232px; border-radius: 15px; }
  .flight-hero::before { background: linear-gradient(180deg, rgba(7, 31, 49, .72) 0%, rgba(7, 31, 49, .94) 75%); }
  .flight-hero-image { height: 100%; object-position: 56% center; opacity: .72; }
  .flight-hero-copy { width: 100%; min-height: 232px; justify-content: center; padding: 22px 21px 20px; }
  .flight-hero h2 { margin-top: 6px; font-size: 34px; }
  .flight-hero-copy > p:not(.flight-hero-label) { max-width: none; margin-top: 10px; font-size: 13px; line-height: 1.45; white-space: nowrap; }
  .flight-hero-foot { margin-top: 16px; font-size: 9px; }
  .flight-image-caption { right: 9px; bottom: 8px; }
  .home-resume { grid-template-columns: 1fr; gap: 10px; padding: 15px; }
  .home-resume-action { grid-column: auto; }
  .home-path { margin-top: 28px; }
  .home-path .flight-section-head h3 { font-size: 22px; }
  .flight-journey { grid-template-columns: 1fr 1fr; gap: 7px; }
  .journey-card { min-height: 99px; padding: 11px; }
  .journey-title { margin-top: 9px; font-size: 12px; }
  .journey-card small { font-size: 9px; }
  .home-route { grid-template-columns: 1fr; }
  .home-route .flight-muted { grid-column: auto; }
  .flight-lab { padding: 14px 11px; }
  .flight-lab .flight-section-head h3 { font-size: 21px; }
  .lab-controls { padding: 19px 16px; }
  .lab-visual { min-height: 325px; }
  .instrument-top { padding-right: 13px; padding-left: 13px; }
  .power-diagram { padding: 12px 11px 14px; }
  .power-chain { grid-template-columns: minmax(0, 1fr) minmax(18px, auto) minmax(0, 1fr) minmax(18px, auto) minmax(0, 1fr); }
  .power-relation-row { grid-template-columns: minmax(0, 1fr) minmax(18px, auto) minmax(0, 1fr); }
  .power-node { min-height: 70px; }
  .power-node strong { font-size: 14px; }
  .power-node span { font-size: 9px; }
  .power-node small { font-size: 7px; }
  .power-edge { min-width: 18px; font-size: 18px; }
  .power-ground { grid-template-columns: auto minmax(0, 1fr); font-size: 8px; }
  .power-ground small { grid-column: 2; }
  .power-bypass-path { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 6px; }
  .instrument-note { display: block; margin-right: 12px; margin-left: 12px; }
  .instrument-note span { display: block; margin-top: 3px; }
  .horizon { width: 210px; }
  .attitude-values { gap: 17px; }
  .card-pad, .quiz-card, .path-panel { padding: 17px; }
  .page-heading h2 { font-size: 26px; }
  .task-guide { grid-template-columns: 1fr; }
  .guide-card { min-height: 0; }
  .checkpoint-bar { grid-template-columns: 1fr; padding: 15px; }
  .checkpoint-meta { grid-column: auto; padding: 10px 0 0; border-top: 1px solid var(--line); border-left: 0; }
  .report-grid { grid-template-columns: 1fr; }
  .assembly-stage, .assembly-parts { padding: 14px; }
  .assembly-parts-grid, .part-grid { grid-template-columns: 1fr 1fr; }
  .quiz-pagination { align-items: stretch; flex-direction: column; }
  .quiz-pagination .button { width: 100%; }
}