:root {
  color-scheme: light;
  --ink: #172128;
  --muted: #58656d;
  --paper: #f5f6f3;
  --surface: #ffffff;
  --surface-2: #edf1f1;
  --line: #cbd2d3;
  --line-strong: #8e9a9f;
  --night: #13232c;
  --blue: #12617d;
  --blue-soft: #e3f0f4;
  --green: #19704c;
  --green-soft: #e3f2e9;
  --red: #a43d35;
  --red-soft: #f8e8e5;
  --gold: #a06b12;
  --gold-bright: #e1a63a;
  --gold-soft: #f7efd9;
  --rail: 260px;
  --content: 980px;
  --font-body: "Microsoft YaHei", "PingFang SC", sans-serif;
  --font-display: "Noto Serif SC", "Source Han Serif SC", "Songti SC", STSong, serif;
}

* { box-sizing: border-box; }
html { background: var(--paper); scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.75;
  letter-spacing: 0;
}
a { color: var(--blue); }
button, input, select { font: inherit; }
button { letter-spacing: 0; }
img, svg { max-width: 100%; }
[hidden] { display: none !important; }

.reading-progress { position: fixed; inset: 0 0 auto var(--rail); z-index: 100; height: 4px; background: transparent; }
.reading-progress i { display: block; width: 100%; height: 100%; transform: scaleX(0); transform-origin: left; background: var(--gold-bright); }

.course-rail {
  position: fixed;
  inset: 0 auto 0 0;
  z-index: 50;
  width: var(--rail);
  padding: 24px 18px;
  overflow-y: auto;
  color: #eaf0f1;
  background: var(--night);
  border-right: 1px solid #31434b;
}
.rail-brand { display: flex; align-items: center; gap: 12px; color: white; text-decoration: none; }
.rail-brand img { width: 42px; height: 42px; border: 1px solid #49616c; border-radius: 6px; }
.rail-brand strong, .rail-brand small { display: block; }
.rail-brand strong { font-family: var(--font-display); font-size: 17px; }
.rail-brand small { color: #aebdc3; font-size: 11px; }
.rail-progress { margin: 25px 0 24px; padding: 14px; border: 1px solid #38505b; border-radius: 5px; background: #182d37; }
.rail-progress > span { color: #9fb0b7; font-size: 11px; text-transform: uppercase; }
.rail-progress > strong { float: right; font-size: 12px; }
.rail-progress > div { height: 4px; margin-top: 10px; background: #31454e; }
.rail-progress i { display: block; width: 0; height: 100%; background: var(--gold-bright); transition: width 240ms ease; }
.rail-chapter { margin: 20px 0; }
.rail-chapter h2 { margin: 0 0 8px; color: #8fa3ac; font-family: var(--font-body); font-size: 11px; text-transform: uppercase; }
.rail-lesson { display: grid; grid-template-columns: 25px 1fr 10px; align-items: center; gap: 7px; min-height: 43px; padding: 5px 7px; color: #c7d2d6; text-decoration: none; border-left: 2px solid transparent; }
.rail-lesson > span { color: #79909a; font-size: 11px; font-variant-numeric: tabular-nums; }
.rail-lesson em { overflow: hidden; font-size: 12px; font-style: normal; line-height: 1.35; text-overflow: ellipsis; white-space: nowrap; }
.rail-lesson > i { width: 7px; height: 7px; border: 1px solid #687c85; border-radius: 50%; }
.rail-lesson:hover { color: white; background: #1a303a; }
.rail-lesson.current { color: white; border-left-color: var(--gold-bright); background: #203640; }
.rail-lesson.complete > i { border-color: #56b989; background: #56b989; box-shadow: 0 0 0 3px rgb(86 185 137 / 14%); }
.rail-reference { display: block; margin-top: 25px; padding: 10px 12px; color: #e8ecee; text-align: center; text-decoration: none; border: 1px solid #4d626b; border-radius: 4px; font-size: 12px; }

.course-page .topbar, .course-page main, .course-page footer,
.course-runtime body:not(.home-page):not(.system-page) .topbar,
.course-runtime body:not(.home-page):not(.system-page) main,
.course-runtime body:not(.home-page):not(.system-page) footer { margin-left: var(--rail); }
.topbar { border-bottom: 1px solid var(--line); background: rgb(255 255 255 / 94%); }
.topbar-inner, body:not(.home-page):not(.system-page) > main, body:not(.home-page):not(.system-page) > footer {
  width: min(calc(100% - 48px), var(--content));
  margin-right: auto;
  padding-left: 0;
}
.topbar-inner { min-height: 56px; display: flex; align-items: center; justify-content: space-between; gap: 18px; }
.course-name { color: var(--ink); font-family: var(--font-display); font-weight: 700; text-decoration: none; }
.lesson-count { color: var(--muted); font-size: 13px; }
body:not(.home-page):not(.system-page) > main { padding-top: 54px; padding-bottom: 80px; }
body:not(.home-page):not(.system-page) > footer { padding-top: 24px; padding-bottom: 80px; border-top: 1px solid var(--line); color: var(--muted); font-size: 13px; }

.eyebrow { color: var(--blue); font-size: 12px; font-weight: 800; text-transform: uppercase; }
h1, h2, h3 { letter-spacing: 0; }
h1 { max-width: 18ch; margin: 8px 0 16px; font-family: var(--font-display); font-size: clamp(36px, 5.2vw, 60px); line-height: 1.16; }
h2 { margin: 62px 0 18px; font-family: var(--font-display); font-size: 30px; line-height: 1.28; }
h3 { margin: 30px 0 10px; font-size: 20px; line-height: 1.35; }
p { margin: 0 0 17px; }
.lead { max-width: 760px; color: #34444c; font-family: var(--font-display); font-size: 21px; line-height: 1.75; }
.goal { max-width: 800px; margin-top: 28px; padding: 17px 20px; border-left: 4px solid var(--gold); background: var(--gold-soft); color: #3f4549; }
.goal strong { color: #76500e; }

.map, .concept-strip { display: grid; gap: 1px; margin: 32px 0; border: 1px solid var(--line); background: var(--line); }
.map { grid-template-columns: repeat(4, 1fr); }
.concept-strip { grid-template-columns: repeat(5, 1fr); }
.map > div, .concept-strip > div { min-height: 115px; padding: 17px; background: var(--surface); }
.map strong, .concept-strip strong { display: block; color: var(--blue); font-size: 14px; }
.map span, .concept-strip span { display: block; margin-top: 6px; color: var(--muted); font-size: 13px; line-height: 1.5; }

.compare { width: 100%; margin: 22px 0 30px; border-collapse: collapse; background: var(--surface); }
.compare th, .compare td { padding: 13px 14px; border: 1px solid var(--line); text-align: left; vertical-align: top; }
.compare th { background: #e9eeee; font-size: 13px; }
.compare td { font-size: 15px; }
.callout, .example, .checkpoint { margin: 26px 0; padding: 20px 22px; border: 1px solid var(--line); border-radius: 6px; background: var(--surface); }
.callout { border-left: 5px solid var(--blue); }
.example { border-left: 5px solid var(--gold); }
.checkpoint { border-left: 5px solid var(--green); }
.callout > :last-child, .example > :last-child, .checkpoint > :last-child { margin-bottom: 0; }
.label { display: block; margin-bottom: 7px; color: var(--muted); font-size: 11px; font-weight: 800; text-transform: uppercase; }
.formula { margin: 20px 0; padding: 18px; overflow-x: auto; background: #e9eeee; font-family: Cambria, "Times New Roman", serif; font-size: 22px; text-align: center; }
.math { font-family: Cambria, "Times New Roman", serif; white-space: nowrap; }
.math i { font-family: inherit; }

.visual-lab { margin: 30px 0; overflow: hidden; border: 1px solid var(--line-strong); border-radius: 6px; background: var(--surface); }
.lab-header { display: flex; align-items: flex-end; justify-content: space-between; gap: 18px; padding: 18px 20px; color: white; background: var(--night); }
.lab-header span { display: block; color: #9fb2ba; font-size: 11px; font-weight: 700; text-transform: uppercase; }
.lab-header strong { display: block; margin-top: 4px; font-family: var(--font-display); font-size: 21px; }
.lab-header em { color: #d5dfe2; font-size: 12px; font-style: normal; }
.lab-controls { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; padding: 18px 20px; border-bottom: 1px solid var(--line); background: #f7f8f6; }
.lab-control label { display: flex; justify-content: space-between; gap: 10px; margin-bottom: 7px; color: var(--muted); font-size: 12px; }
.lab-control output { color: var(--ink); font-weight: 700; font-variant-numeric: tabular-nums; }
.lab-control input[type="range"] { width: 100%; accent-color: var(--blue); }
.lab-stage { padding: 20px; }
.lab-stage svg { display: block; width: 100%; height: auto; }
.lab-readout { display: grid; grid-template-columns: repeat(4, 1fr); border-top: 1px solid var(--line); }
.lab-readout > div { min-height: 88px; padding: 14px 16px; border-right: 1px solid var(--line); }
.lab-readout > div:last-child { border-right: 0; }
.lab-readout span { display: block; color: var(--muted); font-size: 11px; }
.lab-readout strong { display: block; margin-top: 4px; font-size: 20px; font-variant-numeric: tabular-nums; }
.segmented { display: inline-flex; padding: 3px; border: 1px solid #51656e; border-radius: 4px; background: #0f1c22; }
.segmented button { min-height: 36px; padding: 5px 11px; border: 0; border-radius: 3px; color: #bbcad0; background: transparent; cursor: pointer; }
.segmented button[aria-pressed="true"], .segmented button[aria-selected="true"] { color: var(--night); background: var(--gold-bright); }

.option-figure, .convergence-figure { margin: 28px 0; overflow: hidden; border: 1px solid var(--line); border-radius: 6px; background: var(--surface); }
.option-figure svg, .convergence-figure svg { display: block; width: 100%; height: auto; background: #fbfcfc; }
.option-figure figcaption, .convergence-figure figcaption { padding: 14px 18px 18px; border-top: 1px solid var(--line); color: var(--muted); font-size: 14px; }
.chart-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 1px; background: var(--line); }
.option-figure .panel { fill: #fff; stroke: #d9dee1; }
.option-figure .grid, .convergence-figure .grid { stroke: #e2e8e9; stroke-width: 1; }
.option-figure .axis, .convergence-figure .axis { stroke: #68757d; stroke-width: 1.5; }
.option-figure .guide { stroke: #9ba6ac; stroke-width: 1.25; stroke-dasharray: 5 5; }
.option-figure .breakeven { stroke: var(--gold); stroke-width: 1.75; stroke-dasharray: 5 5; }
.option-figure .payoff-area { fill: #dcebf2; }
.option-figure .profit-loss-area { fill: #f8e7e3; }
.option-figure .payoff-line, .option-figure .profit-line { fill: none; stroke-width: 4; stroke-linecap: round; stroke-linejoin: round; vector-effect: non-scaling-stroke; }
.option-figure .payoff-line { stroke: var(--blue); }
.option-figure .profit-line { stroke: var(--red); }
.chart-legend { display: flex; flex-wrap: wrap; gap: 10px 22px; padding: 14px 18px; border-top: 1px solid var(--line); color: var(--muted); font-size: 13px; }
.chart-legend span { display: inline-flex; align-items: center; gap: 8px; }
.chart-legend i { width: 22px; height: 3px; display: inline-block; }
.payoff-key { background: var(--blue); }.profit-key { background: var(--red); }.break-key { background: var(--gold); }
.convergence-figure .spot-line { fill: none; stroke: var(--green); stroke-width: 4; }
.convergence-figure .futures-line { fill: none; stroke: var(--blue); stroke-width: 4; }
.convergence-figure .delivery-line { stroke: var(--gold); stroke-width: 2; stroke-dasharray: 6 5; }
.convergence-figure text { fill: #43515a; font-size: 13px; }
.convergence-figure .chart-heading { fill: var(--ink); font-size: 18px; font-weight: 700; }

.mechanism-flow { display: grid; grid-template-columns: repeat(4, 1fr); gap: 22px; margin: 28px 0; counter-reset: flow; }
.mechanism-flow > div { position: relative; min-height: 120px; padding: 16px; border-top: 3px solid var(--blue); background: var(--surface); counter-increment: flow; }
.mechanism-flow > div::before { content: counter(flow, decimal-leading-zero); display: block; margin-bottom: 8px; color: var(--gold); font-family: var(--font-display); font-weight: 700; }
.mechanism-flow > div:not(:last-child)::after { content: "→"; position: absolute; top: 43%; right: -19px; color: var(--muted); }
.mechanism-flow strong { display: block; font-size: 14px; }
.mechanism-flow span { display: block; margin-top: 5px; color: var(--muted); font-size: 12px; line-height: 1.5; }

.chapter-concepts { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1px; margin: 28px 0; border: 1px solid var(--line); background: var(--line); }
.chapter-concepts article { min-height: 190px; padding: 22px; background: var(--surface); }
.chapter-concepts article > span { color: var(--gold); font-family: var(--font-display); font-size: 13px; font-weight: 700; }
.chapter-concepts h3 { margin: 18px 0 9px; font-family: var(--font-display); }
.chapter-concepts p { color: var(--muted); font-size: 14px; line-height: 1.65; }
.model-card { margin: 28px 0; padding: 22px; border: 1px solid var(--line); border-top: 4px solid var(--blue); background: var(--surface); }
.model-card .formula { margin: 12px 0 15px; }
.chapter-lab { margin: 30px 0; overflow: hidden; border: 1px solid var(--line-strong); border-radius: 6px; background: var(--surface); }
.scenario-meter { display: grid; grid-template-columns: 210px 1fr; gap: 14px 24px; align-items: center; padding: 22px; border-top: 1px solid var(--line); }
.scenario-meter > div:first-child span { display: block; color: var(--muted); font-size: 11px; }
.scenario-meter strong { display: block; margin-top: 3px; font-size: 27px; font-variant-numeric: tabular-nums; }
.scenario-meter p { grid-column: 1 / -1; margin: 0; color: var(--muted); font-size: 14px; }
.meter-track { height: 12px; overflow: hidden; background: var(--surface-2); border: 1px solid var(--line); }
.meter-track i { display: block; width: 0; height: 100%; background: var(--gold-bright); transition: width 180ms ease; }

.quiz { margin: 30px 0; padding: 22px; border: 1px solid var(--line); border-radius: 6px; background: var(--surface); }
.quiz::before { content: "KNOWLEDGE CHECK"; display: block; margin-bottom: 8px; color: var(--blue); font-size: 10px; font-weight: 800; }
.quiz-question { font-weight: 700; }
.quiz-options { display: grid; gap: 10px; margin: 17px 0; }
.quiz-option { display: grid; grid-template-columns: 44px 1fr; align-items: stretch; gap: 10px; }
.quiz-option button { min-height: 44px; border: 1px solid #84929a; border-radius: 4px; background: #edf1f1; color: var(--ink); font-weight: 800; cursor: pointer; }
.quiz-option button:hover, .quiz-option button:focus-visible { background: var(--blue-soft); outline: 2px solid var(--blue); outline-offset: 2px; }
.quiz-option button[aria-pressed="true"] { color: white; background: var(--blue); }
.quiz-option span { align-self: center; }
.feedback { min-height: 52px; padding: 11px 13px; border-radius: 4px; color: var(--muted); background: #f3f5f4; }
.feedback.correct { color: var(--green); background: var(--green-soft); }
.feedback.wrong { color: var(--red); background: var(--red-soft); }

.stepper { margin: 28px 0; overflow: hidden; border: 1px solid var(--line); border-radius: 6px; background: var(--surface); }
.stepper-body { min-height: 205px; padding: 24px; }
.stepper-body [data-step] > span { color: var(--gold); font-size: 11px; font-weight: 800; text-transform: uppercase; }
.stepper-body [data-step] h3 { margin-top: 7px; }
.stepper-nav { display: flex; align-items: center; justify-content: space-between; padding: 12px 16px; border-top: 1px solid var(--line); background: #edf1f1; }
.stepper-nav button { min-width: 44px; min-height: 40px; border: 1px solid var(--line-strong); border-radius: 4px; background: white; cursor: pointer; }
.stepper-nav button:disabled { opacity: .35; cursor: default; }
.stepper-nav span { color: var(--muted); font-size: 12px; font-variant-numeric: tabular-nums; }
.practice-set { margin: 30px 0; border-top: 2px solid var(--night); }
.practice-set details { border-bottom: 1px solid var(--line); background: var(--surface); }
.practice-set summary { padding: 17px 48px 17px 17px; cursor: pointer; font-weight: 700; }
.practice-set details > div { padding: 0 18px 18px; color: #38474e; }
.practice-set .answer { margin-top: 14px; padding: 13px; border-left: 3px solid var(--green); background: var(--green-soft); }

.simulator { margin: 30px 0; overflow: hidden; border: 1px solid var(--line-strong); border-radius: 6px; background: var(--surface); }
.sim-header { display: flex; justify-content: space-between; gap: 16px; padding: 18px 20px; color: white; background: var(--night); }
.sim-header strong { display: block; font-family: var(--font-display); font-size: 20px; }
.sim-header span { display: block; margin-top: 4px; color: #b8c8ce; font-size: 12px; }
.sim-metrics { display: grid; grid-template-columns: repeat(4, 1fr); border-bottom: 1px solid var(--line); }
.sim-metric { padding: 14px 16px; border-right: 1px solid var(--line); }
.sim-metric:last-child { border-right: 0; }
.sim-metric span { display: block; color: var(--muted); font-size: 11px; }
.sim-metric strong { display: block; margin-top: 3px; font-size: 20px; font-variant-numeric: tabular-nums; }
.sim-controls { padding: 18px 20px; }
.sim-controls label { display: block; margin-bottom: 7px; font-weight: 700; }
.sim-input-row { display: grid; grid-template-columns: minmax(150px, 1fr) auto; gap: 10px; }
.sim-input-row input { width: 100%; min-height: 44px; padding: 8px 11px; border: 1px solid #84929a; border-radius: 4px; color: var(--ink); background: white; }
.sim-input-row button, .sim-actions button, .preset-buttons button { min-height: 44px; padding: 8px 13px; border: 1px solid #64747d; border-radius: 4px; color: var(--ink); background: #edf1f1; font-weight: 700; cursor: pointer; }
.sim-input-row button { color: white; border-color: var(--blue); background: var(--blue); }
.preset-buttons, .sim-actions { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 10px; }
.preset-buttons button { font-size: 12px; font-weight: 600; }
.sim-actions [data-top-up] { color: var(--green); border-color: var(--green); }
.sim-actions [data-close] { color: var(--red); border-color: var(--red); }
.sim-status { min-height: 54px; margin-top: 14px; padding: 11px 13px; border-left: 4px solid var(--blue); background: var(--blue-soft); }
.sim-status.warning { color: #792b23; border-left-color: var(--red); background: var(--red-soft); }
.sim-status.success { color: var(--green); border-left-color: var(--green); background: var(--green-soft); }
.sim-table-wrap { overflow-x: auto; border-top: 1px solid var(--line); }
.sim-table { width: 100%; min-width: 690px; border-collapse: collapse; font-size: 13px; }
.sim-table th, .sim-table td { padding: 10px 12px; border-bottom: 1px solid #e4e8ea; text-align: right; font-variant-numeric: tabular-nums; }
.sim-table th:first-child, .sim-table td:first-child { text-align: left; }
.sim-table th { color: #43515a; background: #e9eeee; font-size: 11px; }
.gain { color: var(--green); }.loss { color: var(--red); }

.quote-tape { display: grid; grid-template-columns: repeat(7, minmax(90px, 1fr)); margin: 20px 0; overflow-x: auto; border: 1px solid var(--line); background: var(--surface); }
.quote-tape > div { min-width: 90px; padding: 12px; border-right: 1px solid var(--line); }
.quote-tape span { display: block; color: var(--muted); font-size: 10px; text-transform: uppercase; }
.quote-tape strong { display: block; margin-top: 3px; font-size: 16px; font-variant-numeric: tabular-nums; }

.source-note { margin-top: 44px; padding: 20px 22px; border-top: 2px solid var(--night); border-bottom: 1px solid var(--line); background: #eef1ef; }
.source-note > strong { display: block; margin-bottom: 8px; color: var(--blue); font-size: 11px; text-transform: uppercase; }
.source-note p { margin-bottom: 8px; color: #44535a; font-size: 13px; }
.source-note p:last-child { margin-bottom: 0; }
.lab-grid { fill: none; stroke: #e0e6e7; stroke-width: 1; }
.lab-axis { stroke: #65747b; stroke-width: 1.5; }
.lab-strike { stroke: var(--gold); stroke-width: 2; stroke-dasharray: 6 5; }
.lab-profit-path { fill: none; stroke: var(--blue); stroke-width: 5; stroke-linecap: round; stroke-linejoin: round; }
.lab-spot-dot { fill: var(--red); stroke: white; stroke-width: 3; }
.lab-stage text { fill: var(--muted); font-size: 12px; }

.underlying-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1px; margin: 28px 0; border: 1px solid var(--line); background: var(--line); }
.underlying-grid > div { min-height: 145px; padding: 17px; background: var(--surface); }
.underlying-grid span { color: var(--gold); font-size: 10px; font-weight: 800; }
.underlying-grid strong { display: block; margin-top: 13px; font-family: var(--font-display); font-size: 20px; }
.underlying-grid p { margin-top: 7px; color: var(--muted); font-size: 12px; line-height: 1.5; }
.market-lab { margin: 28px 0; overflow: hidden; border: 1px solid var(--line-strong); border-radius: 6px; background: var(--surface); }
.tab-bar { display: flex; padding: 5px; color: white; background: var(--night); }
.tab-bar button { min-height: 42px; padding: 8px 15px; border: 0; border-radius: 3px; color: #b9c8ce; background: transparent; cursor: pointer; }
.tab-bar button[aria-selected="true"] { color: var(--night); background: var(--gold-bright); font-weight: 800; }
.market-panel { padding: 24px; }
.route-diagram { min-height: 140px; display: grid; grid-template-columns: 1fr auto 1.3fr auto 1fr; align-items: center; gap: 14px; }
.route-diagram.bilateral { grid-template-columns: 1fr 1.4fr 1fr; }
.route-diagram > span { color: var(--muted); font-size: 11px; text-align: center; }
.route-diagram > span::after { content: " →"; color: var(--gold); }
.route-node { display: grid; min-height: 82px; padding: 12px; place-items: center; border: 1px solid var(--line); border-radius: 5px; background: #f3f5f4; text-align: center; font-weight: 700; }
.route-node.hub { color: white; border-color: var(--night); background: var(--night); }
.route-node.bank { color: var(--blue); border-color: #7da6b5; background: var(--blue-soft); }
.route-node.company { color: var(--green); border-color: #80ad95; background: var(--green-soft); }
.panel-facts { display: grid; grid-template-columns: repeat(4, 1fr); margin-top: 20px; border-top: 1px solid var(--line); }
.panel-facts > div { padding: 13px; border-right: 1px solid var(--line); }
.panel-facts > div:last-child { border-right: 0; }
.panel-facts strong, .panel-facts span { display: block; }
.panel-facts strong { color: var(--muted); font-size: 10px; }.panel-facts span { margin-top: 4px; font-size: 13px; }

.motive-board { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; margin: 28px 0; }
.motive-board > div { min-height: 190px; padding: 19px; border-top: 4px solid var(--blue); background: var(--surface); }
.motive-board .hedge { border-color: var(--green); }.motive-board .spec { border-color: var(--red); }.motive-board .arb { border-color: var(--gold); }
.motive-board span { color: var(--muted); font-size: 10px; font-weight: 800; }
.motive-board strong { display: block; margin-top: 27px; font-family: var(--font-display); font-size: 20px; }
.motive-board p { margin-top: 9px; color: var(--muted); font-size: 13px; }
.classifier-lab { margin: 28px 0; overflow: hidden; border: 1px solid var(--line-strong); border-radius: 6px; background: var(--surface); }
.classifier-case { min-height: 150px; padding: 25px; color: white; background: var(--night); }
.classifier-case span { color: var(--gold-bright); font-size: 10px; font-weight: 800; }
.classifier-case strong { display: block; max-width: 700px; margin-top: 18px; font-family: var(--font-display); font-size: 22px; line-height: 1.55; }
.classifier-actions { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1px; background: var(--line); }
.classifier-actions button { min-height: 52px; border: 0; background: #f6f8f7; cursor: pointer; font-weight: 700; }
.classifier-actions button:hover { background: var(--blue-soft); }
.lab-feedback { min-height: 60px; padding: 14px 18px; color: var(--muted); border-top: 1px solid var(--line); background: #f2f4f2; }
.lab-feedback.correct { color: var(--green); background: var(--green-soft); }.lab-feedback.wrong { color: var(--red); background: var(--red-soft); }

.risk-output { display: grid; grid-template-columns: 1fr 1fr 2fr; align-items: center; gap: 20px; padding: 18px 20px; }
.risk-output span, .risk-output strong { display: block; }.risk-output span { color: var(--muted); font-size: 11px; }.risk-output strong { font-size: 25px; }
.risk-meter { height: 12px; overflow: hidden; background: #dce2e1; }
.risk-meter i { display: block; width: 0; height: 100%; background: var(--red); transition: width 180ms ease; }
.risk-matrix { display: grid; grid-template-columns: 1fr 1fr; gap: 1px; margin: 28px 0; border: 1px solid var(--line); background: var(--line); }
.risk-matrix > div { min-height: 170px; padding: 19px; background: var(--surface); }
.risk-matrix span { color: var(--red); font-size: 10px; font-weight: 800; }
.risk-matrix strong { display: block; margin-top: 18px; font-family: var(--font-display); font-size: 21px; }
.risk-matrix p { margin-top: 8px; color: var(--muted); font-size: 13px; }

.margin-system { margin: 28px 0; border: 1px solid var(--line-strong); background: var(--surface); }
.margin-threshold { display: grid; grid-template-columns: 1fr auto; gap: 8px 20px; padding: 16px 20px; color: white; background: var(--night); }
.margin-threshold.maintenance { background: #7d332e; }
.margin-threshold span { color: #b8c7cc; font-size: 11px; font-weight: 800; text-transform: uppercase; }
.margin-threshold strong { grid-row: span 2; font-size: 24px; }
.margin-threshold p { margin: 0; color: #dce4e7; font-size: 12px; }
.margin-zone { min-height: 110px; padding: 18px 20px; border-left: 8px solid var(--green); background: var(--green-soft); }
.margin-zone.danger { border-left-color: var(--red); background: var(--red-soft); }
.margin-zone span { font-weight: 800; }.margin-zone p { margin: 5px 0 0; color: var(--muted); font-size: 13px; }

.contract-sheet { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1px; margin: 28px 0; border: 1px solid var(--line); background: var(--line); }
.contract-sheet > div { min-height: 150px; padding: 17px; background: var(--surface); }
.contract-sheet .contract-title { grid-column: 1 / -1; min-height: auto; color: white; background: var(--night); }
.contract-sheet span { color: var(--blue); font-size: 10px; font-weight: 800; text-transform: uppercase; }
.contract-sheet .contract-title span { color: var(--gold-bright); }
.contract-sheet strong { display: block; margin-top: 12px; font-family: var(--font-display); font-size: 18px; }
.contract-sheet p { margin-top: 7px; color: var(--muted); font-size: 12px; }
.position-ledger { display: grid; grid-template-columns: 1fr 50px 1fr; align-items: stretch; margin: 28px 0; }
.position-ledger > div:not(.ledger-arrow) { min-height: 140px; padding: 20px; border: 1px solid var(--line); background: var(--surface); }
.position-ledger span, .position-ledger strong, .position-ledger em { display: block; }
.position-ledger span { color: var(--muted); font-size: 11px; }.position-ledger strong { margin-top: 17px; font-family: var(--font-display); font-size: 18px; }.position-ledger em { margin-top: 10px; color: var(--green); font-style: normal; }
.ledger-arrow { display: grid; place-items: center; color: var(--gold); font-size: 24px; }
.convergence-lab { margin: 28px 0; overflow: hidden; border: 1px solid var(--line-strong); border-radius: 6px; background: var(--surface); }
.convergence-lab .lab-header button { min-height: 42px; padding: 7px 12px; color: var(--night); border: 0; border-radius: 4px; background: var(--gold-bright); font-weight: 800; cursor: pointer; }
.convergence-lab .lab-controls { grid-template-columns: 1fr 1fr; }
.convergence-bars { padding: 20px; }
.convergence-bars > div { display: grid; grid-template-columns: 90px 1fr; align-items: center; gap: 12px; margin: 12px 0; }
.convergence-bars span { color: var(--muted); font-size: 12px; }
.convergence-bars i { height: 24px; overflow: hidden; background: #e1e6e5; }
.convergence-bars b { display: block; width: 0; height: 100%; background: var(--green); transition: width 260ms ease; }
.convergence-bars > div:nth-child(2) b { background: var(--blue); }

.clearing-chain { display: grid; grid-template-columns: 1fr auto 1fr auto 1fr auto 1fr; align-items: center; gap: 10px; margin: 28px 0; }
.clearing-chain > div { min-height: 145px; padding: 15px; border-top: 3px solid var(--blue); background: var(--surface); }
.clearing-chain > div.central { color: white; border-color: var(--gold-bright); background: var(--night); }
.clearing-chain span { color: var(--muted); font-size: 9px; }.clearing-chain .central span { color: var(--gold-bright); }.clearing-chain strong { display: block; margin-top: 17px; font-size: 15px; }.clearing-chain p { margin-top: 7px; color: var(--muted); font-size: 11px; line-height: 1.45; }.clearing-chain .central p { color: #c4d0d4; }
.ccp-lab { margin: 28px 0; overflow: hidden; border: 1px solid var(--line-strong); border-radius: 6px; background: var(--surface); }
.ccp-panel { padding: 25px; }
.counterparty-map { min-height: 150px; display: flex; align-items: center; justify-content: center; gap: 18px; }
.counterparty-map > div { min-width: 90px; min-height: 90px; display: grid; place-items: center; padding: 12px; border: 1px solid var(--line-strong); border-radius: 50%; background: #eef2f1; text-align: center; font-weight: 800; }
.counterparty-map > div.ccp-node { color: white; border-color: var(--night); background: var(--night); }
.counterparty-map > span { color: var(--muted); font-size: 11px; text-align: center; }
.counterparty-map small { display: block; color: var(--muted); font-size: 9px; }
.ccp-panel > p { margin: 12px 0 0; color: var(--muted); text-align: center; font-size: 13px; }
.waterfall { display: grid; grid-template-columns: repeat(4, 1fr); gap: 5px; margin: 28px 0; }
.waterfall > div { min-height: 195px; padding: 17px; color: white; background: #25404c; }
.waterfall > div:nth-child(2) { background: #315460; }.waterfall > div:nth-child(3) { color: var(--ink); background: var(--gold-soft); }.waterfall > div:nth-child(4) { background: #7d332e; }
.waterfall span { color: var(--gold-bright); font-family: var(--font-display); font-size: 22px; }.waterfall strong { display: block; margin-top: 25px; font-size: 14px; }.waterfall p { margin-top: 8px; color: #d0dce0; font-size: 11px; line-height: 1.5; }.waterfall > div:nth-child(3) p { color: var(--muted); }

.quote-story { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; margin: 20px 0; }
.quote-story > div { min-height: 150px; padding: 17px; border-top: 3px solid var(--blue); background: var(--surface); }
.quote-story strong, .quote-story span { display: block; }.quote-story span { margin-top: 16px; font-size: 18px; font-weight: 800; }.quote-story p { margin-top: 6px; color: var(--muted); font-size: 12px; }
.order-lab { margin: 28px 0; overflow: hidden; border: 1px solid var(--line-strong); border-radius: 6px; background: var(--surface); }
.book-top { display: flex; gap: 18px; color: #b7c6cc; font-size: 11px; }.book-top b { color: var(--gold-bright); }
.order-book { display: grid; grid-template-columns: 1fr 110px 1fr; align-items: stretch; padding: 22px; background: #eef1ef; }
.book-side { display: grid; grid-template-columns: 1fr 1fr; gap: 1px; border: 1px solid var(--line); background: var(--line); }
.book-side > * { min-height: 37px; display: grid; place-items: center; background: white; font-size: 12px; }
.book-side > span { color: var(--muted); background: #e4e9e8; font-size: 9px; }
.book-side.asks strong { color: var(--red); }.book-side.bids strong { color: var(--green); }
.book-spread { display: grid; place-items: center; color: var(--muted); text-align: center; font-size: 9px; }.book-spread strong { display: block; color: var(--gold); font-size: 17px; }
.order-controls { display: grid; grid-template-columns: 1fr 1fr 1fr auto; gap: 12px; padding: 18px 20px; border-top: 1px solid var(--line); }
.order-controls label { color: var(--muted); font-size: 10px; }.order-controls select, .order-controls input { display: block; width: 100%; min-height: 42px; margin-top: 5px; padding: 6px 9px; border: 1px solid var(--line-strong); border-radius: 4px; background: white; }.order-controls button { align-self: end; min-height: 42px; padding: 7px 14px; color: white; border: 0; border-radius: 4px; background: var(--blue); font-weight: 800; cursor: pointer; }
.order-result { min-height: 58px; padding: 14px 20px; color: var(--muted); border-top: 1px solid var(--line); background: #f2f4f2; }.order-result.filled { color: var(--green); background: var(--green-soft); }.order-result.waiting { color: var(--gold); background: var(--gold-soft); }

.cashflow-lab { margin: 28px 0; overflow: hidden; border: 1px solid var(--line-strong); border-radius: 6px; background: var(--surface); }
.cashflow-lab .lab-header .lab-control { min-width: 250px; }.cashflow-lab .lab-header label { color: #afc0c7; }.cashflow-lab .lab-header output { color: var(--gold-bright); }
.cashflow-tracks { padding: 22px; }
.cashflow-track { display: grid; grid-template-columns: 80px 1fr; align-items: center; gap: 14px; padding: 18px 0; border-bottom: 1px solid var(--line); }.cashflow-track:last-child { border-bottom: 0; }.cashflow-track > strong { font-family: var(--font-display); font-size: 20px; }.cashflow-track > p { grid-column: 2; margin: 0; color: var(--muted); font-size: 12px; }
.timeline { display: grid; grid-template-columns: repeat(4, 1fr); gap: 2px; background: var(--line); }.timeline span { min-height: 65px; display: grid; place-items: center; padding: 7px; background: #f5f7f6; color: var(--muted); font-size: 9px; }.timeline em { display: block; color: var(--ink); font-size: 15px; font-style: normal; font-weight: 800; }

.completion-panel { display: flex; align-items: center; justify-content: space-between; gap: 20px; margin: 50px 0 22px; padding: 20px; border: 1px solid #38505b; border-radius: 6px; color: white; background: var(--night); }
.completion-panel span, .completion-panel strong { display: block; }
.completion-panel span { color: var(--gold-bright); font-size: 11px; font-weight: 800; text-transform: uppercase; }
.completion-panel strong { margin-top: 3px; font-size: 14px; }
.completion-panel button { min-height: 44px; padding: 8px 14px; border: 1px solid var(--gold-bright); border-radius: 4px; color: var(--night); background: var(--gold-bright); font-weight: 800; cursor: pointer; }
.lesson-nav { display: flex; justify-content: space-between; gap: 16px; margin-top: 22px; padding-top: 22px; border-top: 1px solid var(--line); }
.lesson-nav a { display: inline-flex; align-items: center; min-height: 44px; }
.mobile-dock { display: none; }

/* Course home */
.home-page { background: #f2f4f1; }
.home-header { width: min(calc(100% - 48px), 1220px); min-height: 78px; margin: auto; display: flex; align-items: center; justify-content: space-between; }
.home-brand { display: flex; align-items: center; gap: 12px; color: var(--ink); font-family: var(--font-display); font-weight: 700; line-height: 1.2; text-decoration: none; }
.home-brand img { width: 43px; height: 43px; border-radius: 6px; }
.home-brand small { color: var(--muted); font-family: var(--font-body); font-size: 10px; font-weight: 500; }
.reference-link { color: var(--ink); text-decoration: none; border-bottom: 1px solid var(--ink); }
.home-main { width: min(calc(100% - 48px), 1220px); margin: auto; }
.home-intro { min-height: 610px; display: grid; grid-template-columns: .86fr 1.14fr; align-items: center; gap: 64px; border-top: 1px solid var(--line); }
.home-intro h1 { max-width: 12ch; font-size: clamp(46px, 6.3vw, 78px); }
.home-intro p { max-width: 610px; color: #435159; font-size: 18px; }
.primary-action { display: inline-flex; align-items: center; justify-content: space-between; gap: 30px; min-width: 240px; min-height: 52px; margin-top: 20px; padding: 10px 16px; color: white; text-decoration: none; border-radius: 4px; background: var(--night); }
.primary-action b { color: var(--gold-bright); }
.market-display { overflow: hidden; border: 1px solid #3b4f58; border-radius: 6px; color: white; background: var(--night); box-shadow: 0 26px 70px rgb(25 42 49 / 16%); }
.ticker { display: grid; grid-template-columns: 1fr auto; padding: 15px 18px; border-bottom: 1px solid #354a53; }
.ticker span, .ticker em { color: #8fa3ac; font-size: 10px; font-style: normal; }
.ticker strong { grid-row: span 2; color: var(--gold-bright); font-size: 24px; font-variant-numeric: tabular-nums; }
.market-display svg { display: block; width: 100%; }
.display-grid { fill: none; stroke: #29404a; stroke-width: 1; }
.display-price { fill: none; stroke: #51b488; stroke-width: 5; }
.display-margin { fill: none; stroke: #72b5d1; stroke-width: 4; }
.display-alert { stroke: #df6258; stroke-width: 2; stroke-dasharray: 7 7; }
.market-display text { fill: #a7bac1; font-size: 10px; }
.display-legend { display: flex; gap: 24px; padding: 12px 18px; border-top: 1px solid #354a53; color: #aab9bf; font-size: 10px; }
.display-legend span::before { content: ""; display: inline-block; width: 12px; height: 3px; margin-right: 6px; vertical-align: middle; background: #51b488; }
.display-legend span:nth-child(2)::before { background: #72b5d1; }.display-legend span:nth-child(3)::before { background: #df6258; }
.home-progress { display: grid; grid-template-columns: 160px 1fr 340px; align-items: center; gap: 24px; padding: 22px 26px; color: white; background: var(--night); }
.home-progress span, .home-progress strong { display: block; }
.home-progress span { color: #9fb0b7; font-size: 10px; text-transform: uppercase; }
.home-progress strong { font-size: 22px; }
.progress-track { height: 6px; background: #324852; }
.progress-track i { display: block; width: 0; height: 100%; background: var(--gold-bright); }
.home-progress p { margin: 0; color: #b6c3c8; font-size: 12px; }
.course-outline, .study-method { padding: 92px 0 36px; }
.section-heading span { color: var(--blue); font-size: 11px; font-weight: 800; }
.section-heading h2 { margin: 4px 0 36px; font-size: 40px; }
.chapter-band { display: grid; grid-template-columns: 90px 1fr; gap: 24px; margin-top: 48px; padding: 24px 0; border-top: 2px solid var(--night); }
.chapter-band > strong { color: var(--gold); font-family: var(--font-display); font-size: 40px; }
.chapter-band h3 { margin: 0; font-family: var(--font-display); font-size: 25px; }
.chapter-band p { margin: 6px 0 0; color: var(--muted); }
.chapter-band.second { margin-top: 70px; }
.lesson-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1px; border: 1px solid var(--line); background: var(--line); }
.lesson-grid.five { grid-template-columns: repeat(5, 1fr); }
.lesson-grid a { position: relative; min-height: 220px; padding: 20px; color: var(--ink); text-decoration: none; background: white; transition: transform 160ms ease, background 160ms ease; }
.lesson-grid a:hover { z-index: 2; transform: translateY(-5px); background: #fbfcfa; box-shadow: 0 12px 26px rgb(25 42 49 / 12%); }
.lesson-grid a > span { color: var(--blue); font-size: 12px; font-weight: 800; }
.lesson-grid a h3 { margin: 32px 0 8px; font-family: var(--font-display); font-size: 20px; }
.lesson-grid a p { color: var(--muted); font-size: 13px; line-height: 1.5; }
.lesson-grid a em { position: absolute; bottom: 18px; color: #879399; font-size: 10px; font-style: normal; }
.lesson-grid a.complete::after { content: "已完成"; position: absolute; top: 16px; right: 16px; padding: 2px 7px; color: var(--green); border: 1px solid #75a88e; border-radius: 10px; font-size: 9px; }
.study-method ol { display: grid; grid-template-columns: repeat(4, 1fr); gap: 22px; margin: 0; padding: 0; list-style: none; counter-reset: method; }
.study-method li { min-height: 170px; padding: 18px; border-top: 3px solid var(--blue); background: white; counter-increment: method; }
.study-method li::before { content: "0" counter(method); display: block; color: var(--gold); font-family: var(--font-display); font-size: 24px; }
.study-method strong, .study-method span { display: block; }
.study-method strong { margin-top: 18px; }.study-method span { margin-top: 6px; color: var(--muted); font-size: 13px; }
.home-footer { width: min(calc(100% - 48px), 1220px); margin: 70px auto 0; padding: 28px 0 50px; border-top: 1px solid var(--line); color: var(--muted); font-size: 12px; }
.route-intro { max-width: 760px; color: var(--muted); }
.route-tabs { display: flex; gap: 4px; margin: 28px 0 20px; overflow-x: auto; border-bottom: 1px solid var(--line); }
.route-tabs button { min-height: 44px; padding: 8px 16px; border: 0; border-bottom: 3px solid transparent; color: var(--muted); background: transparent; cursor: pointer; white-space: nowrap; }
.route-tabs button[aria-selected="true"] { color: var(--ink); border-bottom-color: var(--gold); font-weight: 700; }
.route-summary { display: grid; grid-template-columns: 130px 230px 1fr; gap: 18px; align-items: baseline; margin-bottom: 18px; padding: 16px 18px; color: white; background: var(--night); }
.route-summary strong { font-family: var(--font-display); font-size: 19px; }
.route-summary span { color: var(--gold-bright); font-size: 13px; }
.route-summary p { margin: 0; color: #b8c7cc; font-size: 13px; }
.route-grid { grid-template-columns: repeat(4, 1fr); }
.map-link { margin-top: 24px; text-align: right; }

.system-page { min-height: 100vh; display: grid; place-items: center; background: var(--paper); }
.system-page main { width: min(calc(100% - 40px), 620px); }
.system-page img { width: 64px; margin-bottom: 24px; border-radius: 8px; }
.system-page h1 { font-size: 48px; }

@media (max-width: 1120px) {
  :root { --rail: 224px; }
  .lesson-grid.five { grid-template-columns: repeat(3, 1fr); }
  .home-intro { grid-template-columns: 1fr 1fr; gap: 34px; }
}

@media (max-width: 820px) {
  :root { --rail: 0px; }
  .course-rail { display: none; }
  .reading-progress { left: 0; }
  .course-runtime body:not(.home-page):not(.system-page) .topbar,
  .course-runtime body:not(.home-page):not(.system-page) main,
  .course-runtime body:not(.home-page):not(.system-page) footer { margin-left: 0; }
  .mobile-dock { position: fixed; inset: auto 0 0 0; z-index: 90; height: 58px; display: grid; grid-template-columns: 1fr 1.5fr 1fr; align-items: center; border-top: 1px solid #3c5059; background: var(--night); }
  .mobile-dock a, .mobile-dock span { display: grid; min-height: 58px; place-items: center; color: white; text-decoration: none; }
  .mobile-dock a:nth-child(2) { border-inline: 1px solid #3c5059; color: var(--gold-bright); font-size: 13px; }
  body:not(.home-page):not(.system-page) > footer { padding-bottom: 95px; }
  .map { grid-template-columns: repeat(2, 1fr); }
  .concept-strip { grid-template-columns: repeat(3, 1fr); }
  .mechanism-flow { grid-template-columns: repeat(2, 1fr); }
  .mechanism-flow > div:nth-child(2)::after { display: none; }
  .chapter-concepts { grid-template-columns: 1fr; }
  .chapter-concepts article { min-height: 0; }
  .home-intro { min-height: auto; grid-template-columns: 1fr; padding: 70px 0; }
  .market-display { max-width: 650px; }
  .home-progress { grid-template-columns: 130px 1fr; }
  .home-progress p { grid-column: 1 / -1; }
  .lesson-grid, .lesson-grid.five { grid-template-columns: repeat(2, 1fr); }
  .route-grid { grid-template-columns: repeat(2, 1fr); }
  .route-summary { grid-template-columns: 1fr 1fr; }
  .route-summary p { grid-column: 1 / -1; }
  .study-method ol { grid-template-columns: repeat(2, 1fr); }
  .underlying-grid, .contract-sheet { grid-template-columns: repeat(2, 1fr); }
  .contract-sheet .contract-title { grid-column: 1 / -1; }
  .route-diagram { grid-template-columns: 1fr auto 1.2fr auto 1fr; gap: 8px; }
  .panel-facts { grid-template-columns: 1fr 1fr; }
  .panel-facts > div:nth-child(2) { border-right: 0; }
  .motive-board { grid-template-columns: 1fr; }
  .clearing-chain { grid-template-columns: 1fr 1fr; }
  .clearing-chain > b { display: none; }
  .waterfall { grid-template-columns: 1fr 1fr; }
  .order-controls { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 560px) {
  body { font-size: 16px; }
  .topbar-inner, body:not(.home-page):not(.system-page) > main, body:not(.home-page):not(.system-page) > footer { width: min(calc(100% - 30px), var(--content)); }
  body:not(.home-page):not(.system-page) > main { padding-top: 36px; }
  h1 { font-size: 36px; }
  h2 { margin-top: 48px; font-size: 27px; }
  .lead { font-size: 18px; }
  .map, .concept-strip { grid-template-columns: 1fr 1fr; }
  .compare { display: block; overflow-x: auto; white-space: normal; }
  .chart-grid { grid-template-columns: 1fr; }
  .mechanism-flow { grid-template-columns: 1fr; gap: 12px; }
  .mechanism-flow > div::after { display: none; }
  .lab-header, .sim-header { display: block; }
  .lab-header .segmented { margin-top: 12px; }
  .lab-controls { grid-template-columns: 1fr; }
  .scenario-meter { grid-template-columns: 1fr; }
  .lab-readout, .sim-metrics { grid-template-columns: 1fr 1fr; }
  .lab-readout > div:nth-child(2), .sim-metric:nth-child(2) { border-right: 0; }
  .lab-readout > div, .sim-metric { border-bottom: 1px solid var(--line); }
  .sim-input-row { grid-template-columns: 1fr; }
  .completion-panel { display: block; }
  .completion-panel button { width: 100%; margin-top: 15px; }
  .lesson-nav { display: none; }
  .home-header, .home-main, .home-footer { width: min(calc(100% - 30px), 1220px); }
  .home-intro h1 { font-size: 42px; }
  .market-display svg { min-height: 230px; }
  .display-legend { flex-wrap: wrap; gap: 8px 16px; }
  .home-progress { grid-template-columns: 1fr; }
  .home-progress p { grid-column: auto; }
  .course-outline, .study-method { padding-top: 66px; }
  .section-heading h2 { font-size: 32px; }
  .chapter-band { grid-template-columns: 55px 1fr; }
  .lesson-grid, .lesson-grid.five { grid-template-columns: 1fr; }
  .route-grid, .route-summary { grid-template-columns: 1fr; }
  .route-summary p { grid-column: auto; }
  .lesson-grid a { min-height: 180px; }
  .study-method ol { grid-template-columns: 1fr; }
  .underlying-grid, .contract-sheet, .risk-matrix, .quote-story { grid-template-columns: 1fr; }
  .route-diagram, .route-diagram.bilateral { grid-template-columns: 1fr; }
  .route-diagram > span::after { content: " ↓"; }
  .panel-facts { grid-template-columns: 1fr; }
  .panel-facts > div { border-right: 0; border-bottom: 1px solid var(--line); }
  .tab-bar { overflow-x: auto; }
  .tab-bar button { flex: 0 0 auto; }
  .classifier-actions { grid-template-columns: 1fr; }
  .risk-output { grid-template-columns: 1fr 1fr; }
  .risk-output .risk-meter { grid-column: 1 / -1; }
  .position-ledger { grid-template-columns: 1fr; }
  .ledger-arrow { min-height: 42px; transform: rotate(90deg); }
  .convergence-lab .lab-controls { grid-template-columns: 1fr; }
  .clearing-chain, .waterfall { grid-template-columns: 1fr; }
  .counterparty-map { flex-direction: column; }
  .counterparty-map > span::after { content: " ↓"; color: var(--gold); }
  .order-book { grid-template-columns: 1fr; gap: 12px; }
  .book-spread { min-height: 54px; }
  .order-controls { grid-template-columns: 1fr; }
  .cashflow-lab .lab-header .lab-control { min-width: 0; margin-top: 15px; }
  .cashflow-track { grid-template-columns: 1fr; }
  .cashflow-track > p { grid-column: 1; }
  .timeline { grid-template-columns: 1fr 1fr; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition-duration: .01ms !important; animation-duration: .01ms !important; }
}

@media print {
  .course-rail, .topbar, .mobile-dock, .reading-progress, .lesson-nav, .completion-panel, .quiz-options button { display: none !important; }
  body { background: white; font-size: 11pt; }
  body:not(.home-page):not(.system-page) > main, body:not(.home-page):not(.system-page) > footer { width: 100%; margin: 0; }
  .visual-lab, .quiz, .callout, .example, .checkpoint, .practice-set details { break-inside: avoid; }
}