:root {
  --ink: #17231e;
  --paper: #f5f0e6;
  --cream: #fbf8f1;
  --green: #184b3b;
  --green-2: #2d6b55;
  --orange: #f26a3d;
  --yellow: #f4c95d;
  --line: rgba(23, 35, 30, 0.16);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: "PingFang SC", "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
}
button, input { font: inherit; }
button { color: inherit; }
a { color: inherit; text-decoration: none; }

.hero {
  min-height: 720px;
  padding: 0 max(5vw, 24px) 80px;
  color: #f8f5ed;
  background:
    radial-gradient(circle at 78% 16%, rgba(244, 201, 93, 0.17), transparent 23%),
    linear-gradient(135deg, #10382c 0%, #184b3b 58%, #0e3026 100%);
  overflow: hidden;
  position: relative;
}
.hero::after {
  content: "";
  position: absolute;
  width: 460px;
  height: 460px;
  border: 1px solid rgba(255,255,255,.09);
  border-radius: 50%;
  right: -150px;
  bottom: -220px;
  box-shadow: 0 0 0 70px rgba(255,255,255,.025), 0 0 0 140px rgba(255,255,255,.02);
}
.topbar {
  max-width: 1220px;
  height: 88px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid rgba(255,255,255,.13);
  position: relative;
  z-index: 2;
}
.brand { display: flex; align-items: center; gap: 12px; font-size: 15px; font-weight: 700; letter-spacing: .06em; }
.brandMark { width: 34px; height: 34px; display: grid; place-items: center; color: var(--green); background: var(--yellow); border-radius: 50% 50% 50% 12%; font-family: STKaiti, KaiTi, serif; font-size: 20px; }
.navLink { color: rgba(255,255,255,.78); font-size: 14px; transition: color .2s; }
.navLink:hover { color: white; }
.heroGrid { max-width: 1220px; margin: 82px auto 0; display: grid; grid-template-columns: 1.03fr .97fr; align-items: center; gap: clamp(50px, 7vw, 100px); position: relative; z-index: 1; }
.eyebrow { display: flex; gap: 9px; flex-wrap: wrap; margin: 0 0 26px; }
.eyebrow span { padding: 7px 11px; border: 1px solid rgba(255,255,255,.19); border-radius: 999px; color: rgba(255,255,255,.72); font-size: 12px; letter-spacing: .09em; }
.hero h1 { margin: 0; font-family: STKaiti, KaiTi, "Songti SC", serif; font-size: clamp(50px, 5.6vw, 82px); font-weight: 500; line-height: 1.08; letter-spacing: -.04em; }
.hero h1 em { color: var(--yellow); font-style: normal; position: relative; }
.lead { max-width: 560px; margin: 28px 0 34px; color: rgba(255,255,255,.72); font-size: 17px; line-height: 1.9; }
.answerStrip { width: fit-content; display: flex; align-items: baseline; gap: 11px; padding: 14px 20px; border-left: 3px solid var(--orange); background: rgba(255,255,255,.07); }
.answerStrip span { color: rgba(255,255,255,.69); font-size: 13px; }
.answerStrip strong { color: white; font-family: Georgia, serif; font-size: 34px; line-height: 1; }
.problemCard { position: relative; padding: 40px 42px 38px; color: var(--ink); background: #fbf8ef; border-radius: 4px; box-shadow: 22px 24px 0 rgba(0,0,0,.13); transform: rotate(1.1deg); }
.problemCard::before { content: ""; position: absolute; inset: 9px; border: 1px solid rgba(23,35,30,.1); pointer-events: none; }
.paperClip { position: absolute; width: 44px; height: 14px; top: 18px; right: 60px; background: rgba(242,106,61,.78); transform: rotate(-3deg); }
.cardLabel { margin: 0 0 18px; color: var(--orange); font-size: 12px; font-weight: 800; letter-spacing: .2em; }
.problemText { margin: 0; font-family: STKaiti, KaiTi, "Songti SC", serif; font-size: clamp(20px, 2vw, 27px); line-height: 1.8; }
.knownGrid { margin-top: 26px; padding-top: 22px; border-top: 1px dashed rgba(23,35,30,.2); display: grid; gap: 11px; }
.knownGrid div { display: grid; grid-template-columns: 46px 1fr; align-items: center; gap: 14px; }
.knownGrid span { color: #777d78; font-size: 12px; }
.knownGrid b { font-size: 14px; font-weight: 650; }

.simSection, .methodSection, .reasonSection, .solutionSection, .calculatorSection, .trajectorySection { padding: 100px max(5vw, 24px); }
.simSection { max-width: 1380px; margin: 0 auto; }
.sectionHeading { max-width: 1220px; margin: 0 auto 42px; display: grid; grid-template-columns: 1fr 420px; gap: 60px; align-items: end; }
.sectionNo { margin: 0 0 10px; color: var(--orange); font-size: 12px; font-weight: 800; letter-spacing: .16em; }
.sectionHeading h2, .reasonIntro h2, .solutionTitle h2, .calculatorSection h2 { margin: 0; font-family: STKaiti, KaiTi, "Songti SC", serif; font-size: clamp(34px, 4vw, 54px); font-weight: 500; line-height: 1.18; }
.sectionHeading > p { margin: 0; color: #65716b; font-size: 14px; line-height: 1.8; }
.sectionHeading > p b { color: var(--green); }
.simCard { max-width: 1220px; margin: 0 auto; background: var(--cream); border: 1px solid var(--line); border-radius: 18px; box-shadow: 0 20px 60px rgba(33,50,41,.08); overflow: hidden; }
.simControls { padding: 20px 24px; display: flex; gap: 8px; border-bottom: 1px solid var(--line); }
.simControls button { min-height: 42px; padding: 0 18px; border: 1px solid var(--line); border-radius: 999px; background: transparent; font-size: 13px; font-weight: 700; cursor: pointer; transition: .2s ease; }
.simControls button:hover { transform: translateY(-1px); border-color: var(--green-2); }
.simControls button.active { color: white; background: var(--green); border-color: var(--green); }
.simControls .playButton { margin-left: auto; color: var(--orange); border-color: rgba(242,106,61,.35); }
.simControls .playButton span { margin-right: 7px; }
.simControls .playButton:disabled { cursor: default; opacity: .7; transform: none; }
.roadStage { min-height: 270px; padding: 88px 8% 48px; position: relative; }
.road { height: 24px; position: relative; border-radius: 999px; background: #d6d2c6; border: 1px solid #c2bcad; box-shadow: inset 0 5px 10px rgba(33,50,41,.08); }
.roadCenter { position: absolute; height: 2px; left: 2%; right: 2%; top: 10px; background: repeating-linear-gradient(90deg, rgba(255,255,255,.9) 0 28px, transparent 28px 47px); }
.place { position: absolute; top: 42px; display: flex; flex-direction: column; align-items: center; }
.placeA { left: 8%; transform: translateX(-50%); }
.placeB { right: 8%; transform: translateX(50%); }
.place b { width: 44px; height: 44px; display: grid; place-items: center; color: white; background: var(--ink); border-radius: 50% 50% 6px 50%; font-family: Georgia, serif; font-size: 20px; }
.placeB b { border-radius: 50% 50% 50% 6px; background: var(--orange); }
.place span { margin-top: 7px; color: #6e7772; font-size: 11px; }
.car { position: absolute; top: -57px; display: flex; flex-direction: column; align-items: center; transform: translateX(-50%); transition: left .02s linear; z-index: 3; }
.carIcon { display: block; font-size: 35px; line-height: 1; filter: drop-shadow(0 5px 3px rgba(0,0,0,.16)); }
.car span:last-child { margin-top: 5px; min-width: 24px; padding: 2px 7px; color: white; background: var(--green); border-radius: 999px; text-align: center; font-size: 10px; font-weight: 800; }
.carB span:last-child { background: var(--orange); }
.flip { transform: scaleX(-1); }
.meetingPin { position: absolute; width: 25px; height: 25px; top: 36px; display: grid; place-items: center; transform: translateX(-50%) scale(.7); border-radius: 50%; color: white; background: var(--orange); font: 700 11px Georgia, serif; opacity: 0; transition: .3s ease; }
.meetingPin::before { content: ""; position: absolute; width: 1px; height: 20px; bottom: 24px; background: var(--orange); }
.meetingPin.visible { opacity: 1; transform: translateX(-50%) scale(1); }
.liveStats { display: grid; grid-template-columns: repeat(3, 1fr); border-top: 1px solid var(--line); }
.liveStats div { min-height: 90px; padding: 20px 28px; display: flex; flex-direction: column; justify-content: center; gap: 7px; border-right: 1px solid var(--line); }
.liveStats div:last-child { border: 0; }
.liveStats span { color: #79817c; font-size: 11px; }
.liveStats strong { font-family: STKaiti, KaiTi, serif; font-size: 21px; font-weight: 600; }

.methodSection { color: white; background: var(--green); }
.sectionHeading.light > p { color: rgba(255,255,255,.6); }
.methodSection .sectionNo { color: var(--yellow); }
.oddCards { max-width: 1220px; margin: 0 auto; display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; }
.oddCards article { min-height: 270px; padding: 28px; position: relative; color: var(--ink); background: #f1ecdf; border-radius: 10px; overflow: hidden; }
.oddCards article.focusCard { background: var(--yellow); transform: translateY(-10px); box-shadow: 0 18px 0 rgba(0,0,0,.12); }
.stepTop { display: flex; justify-content: space-between; align-items: center; }
.stepTop span { font-size: 14px; font-weight: 800; }
.stepTop b { color: rgba(23,35,30,.13); font: 700 42px Georgia, serif; }
.segments { min-height: 73px; margin: 28px 0 24px; display: flex; gap: 4px; align-items: center; }
.segments i { flex: 1; height: 8px; position: relative; background: var(--green); }
.segments i::before, .segments i::after { content: ""; position: absolute; width: 7px; height: 7px; top: 50%; border-radius: 50%; background: var(--orange); transform: translateY(-50%); }
.segments i::before { left: -2px; }
.segments i::after { right: -2px; }
.equation { display: flex; align-items: baseline; gap: 8px; }
.equation strong { color: var(--orange); font: 700 46px Georgia, serif; }
.equation span { color: #68716c; }
.equation b { margin-left: auto; font-size: 16px; }
.focusCard .equation strong { color: var(--green); }
.focusCard > p { margin: 17px 0 0; padding-top: 14px; border-top: 1px solid rgba(23,35,30,.18); font-size: 12px; font-weight: 700; }
.ruleBox { max-width: 1220px; margin: 44px auto 0; padding: 34px 40px; display: grid; grid-template-columns: 1fr auto 1fr; align-items: center; gap: 50px; border: 1px solid rgba(255,255,255,.16); border-radius: 10px; background: rgba(0,0,0,.08); }
.ruleTag { padding: 5px 8px; color: var(--green); background: var(--yellow); border-radius: 3px; font-size: 10px; font-weight: 800; }
.ruleBox p { margin: 11px 0 0; color: rgba(255,255,255,.65); font-size: 13px; }
.formula { display: flex; align-items: baseline; gap: 10px; font-family: Georgia, "Times New Roman", serif; }
.formula span { color: rgba(255,255,255,.55); font-size: 25px; }
.formula b { color: var(--yellow); font-size: clamp(31px, 4vw, 48px); }
.ruleBox .formulaExplain { margin: 0; padding-left: 28px; border-left: 1px solid rgba(255,255,255,.18); line-height: 1.8; }

.reasonSection { max-width: 1320px; margin: 0 auto; display: grid; grid-template-columns: .72fr 1.28fr; align-items: center; gap: 80px; }
.reasonIntro > p:last-child { color: #66716b; line-height: 1.9; }
.unfolded { padding: 46px 44px; border: 1px solid var(--line); background: var(--cream); box-shadow: 12px 14px 0 rgba(24,75,59,.08); }
.unfoldedLabels, .unfoldedLine { display: grid; grid-template-columns: repeat(7, 1fr); }
.unfoldedLabels span { color: #69736e; text-align: center; font: 700 13px Georgia, serif; }
.unfoldedLine { margin: 20px 7.14% 26px; grid-template-columns: repeat(6, 1fr); height: 8px; background: repeating-linear-gradient(90deg, var(--green) 0 calc(16.666% - 3px), transparent calc(16.666% - 3px) 16.666%); }
.unfoldedLine i { width: 15px; height: 15px; margin-top: -4px; margin-left: -7px; border: 3px solid var(--cream); border-radius: 50%; background: var(--orange); box-shadow: 0 0 0 1px var(--orange); }
.unfoldedLine i:last-child { justify-self: end; margin-left: 0; margin-right: -7px; }
.unfoldedCount { display: flex; justify-content: space-between; gap: 8px; }
.unfoldedCount span { padding: 7px 9px; color: var(--green); background: rgba(24,75,59,.08); border-radius: 3px; font-size: 11px; font-weight: 700; }

.solutionSection { max-width: 1320px; margin: 0 auto; padding-top: 20px; display: grid; grid-template-columns: 1.35fr .65fr; gap: 20px; }
.solutionCard { padding: 48px; color: white; background: var(--ink); border-radius: 14px; }
.solutionTitle { display: flex; align-items: end; justify-content: space-between; gap: 20px; padding-bottom: 26px; border-bottom: 1px solid rgba(255,255,255,.13); }
.solutionTitle > span { order: 2; color: var(--yellow); font-size: 11px; font-weight: 800; letter-spacing: .16em; }
.solutionCard ol { margin: 32px 0; padding: 0; display: grid; gap: 23px; list-style: none; }
.solutionCard li { display: grid; grid-template-columns: 42px 1fr; gap: 14px; }
.solutionCard li > span { width: 34px; height: 34px; display: grid; place-items: center; color: var(--ink); background: var(--yellow); border-radius: 50%; font-size: 12px; font-weight: 800; }
.solutionCard li p { margin: 0 0 7px; color: rgba(255,255,255,.57); font-size: 13px; }
.solutionCard li strong { font-family: Georgia, STKaiti, serif; font-size: 25px; font-weight: 500; }
.finalAnswer { padding: 21px 24px; display: flex; align-items: center; gap: 14px; color: var(--ink); background: var(--yellow); border-radius: 7px; }
.finalAnswer span { width: 27px; height: 27px; display: grid; place-items: center; color: white; background: var(--orange); border-radius: 50%; font-size: 12px; font-weight: 800; }
.finalAnswer p { margin: 0; }
.finalAnswer strong { margin-left: auto; font-family: STKaiti, KaiTi, serif; font-size: 27px; }
.pitfallCard { padding: 38px; border: 1px solid rgba(242,106,61,.28); border-radius: 14px; background: #fff7ed; }
.pitfallCard h3 { margin: 0; color: var(--orange); font: 500 32px STKaiti, KaiTi, serif; }
.pitfallCard > p:not(.cardLabel):not(.note) { color: #67716c; font-size: 13px; line-height: 1.7; }
.mapping { display: grid; grid-template-columns: 80px repeat(3, 1fr); margin: 24px 0; border: 1px solid rgba(23,35,30,.12); }
.mapping > * { padding: 10px 6px; border-right: 1px solid rgba(23,35,30,.1); border-bottom: 1px solid rgba(23,35,30,.1); text-align: center; font-size: 12px; }
.mapping > :nth-child(n+5) { border-bottom: 0; }
.mapping > :nth-child(4), .mapping > :nth-child(8) { border-right: 0; }
.mapping span { color: #737b77; background: rgba(24,75,59,.05); }
.mapping b { color: var(--green); }
.note { margin: 0; padding: 15px; color: #795a44; background: rgba(242,106,61,.08); font-size: 12px; line-height: 1.75; }

.calculatorSection { color: white; background: var(--orange); display: grid; grid-template-columns: .8fr 1.2fr; align-items: center; gap: 80px; }
.calculatorSection > div:first-child { justify-self: end; max-width: 440px; }
.calculatorSection .sectionNo { color: var(--ink); }
.calculatorSection > div:first-child > p:last-child { color: rgba(255,255,255,.74); line-height: 1.8; }
.calculator { max-width: 700px; display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.calculator label { padding: 17px 18px; display: grid; grid-template-columns: 1fr 78px auto; align-items: center; gap: 8px; color: #6a6f6b; background: white; border-radius: 7px; font-size: 12px; }
.calculator input { width: 78px; padding: 6px; color: var(--ink); background: #f4f0e7; border: 1px solid rgba(23,35,30,.12); border-radius: 4px; font: 700 19px Georgia, serif; text-align: center; outline: 0; }
.calculator input:focus { border-color: var(--green); box-shadow: 0 0 0 3px rgba(24,75,59,.12); }
.calculatorResult { grid-column: 1 / -1; min-height: 105px; padding: 20px 24px; display: flex; align-items: baseline; gap: 12px; color: var(--ink); background: var(--yellow); border-radius: 7px; }
.calculatorResult span { margin-right: auto; font-weight: 800; }
.calculatorResult strong { font: 700 54px Georgia, serif; }
.calculatorResult b { font-size: 14px; }

.trajectorySection { background: #ece5d7; }
.trajectoryHeading { max-width: 1220px; margin: 0 auto 38px; display: grid; grid-template-columns: 1fr 440px; gap: 60px; align-items: end; }
.trajectoryHeading h2 { margin: 0; font: 500 clamp(34px, 4vw, 54px)/1.18 STKaiti, KaiTi, "Songti SC", serif; }
.trajectoryHeading > p { margin: 0; color: #65716b; font-size: 14px; line-height: 1.85; }
.trajectoryHeading > p b { color: var(--green); }
.trailTabs { max-width: 1220px; margin: 0 auto 14px; padding: 14px; display: flex; align-items: center; gap: 8px; background: rgba(255,255,255,.5); border: 1px solid var(--line); border-radius: 12px; }
.trailTabs button { min-height: 42px; padding: 0 18px; border: 1px solid var(--line); border-radius: 999px; background: transparent; font-size: 13px; font-weight: 750; cursor: pointer; transition: .2s ease; }
.trailTabs button:hover { border-color: var(--green); }
.trailTabs button.active { color: white; background: var(--green); border-color: var(--green); }
.trailTabs > span { margin-left: auto; padding-right: 8px; color: var(--orange); font: 600 17px STKaiti, KaiTi, serif; }
.trailBoard { max-width: 1220px; margin: 0 auto; display: grid; gap: 12px; }
.vehicleTrail { padding: 26px 28px 30px; background: var(--cream); border: 1px solid var(--line); border-radius: 13px; overflow: hidden; }
.vehicleTrail.fast { border-left: 5px solid var(--green); }
.vehicleTrail.slow { border-left: 5px solid var(--orange); }
.vehicleHead { display: flex; align-items: center; justify-content: space-between; gap: 24px; padding-bottom: 22px; border-bottom: 1px dashed rgba(23,35,30,.15); }
.vehicleHead > div { display: flex; align-items: center; gap: 13px; }
.vehicleIcon { font-size: 31px; filter: drop-shadow(0 4px 3px rgba(0,0,0,.13)); }
.vehicleHead b { display: block; font-size: 14px; }
.vehicleHead small { display: block; margin-top: 4px; color: #7d8581; font-size: 10px; }
.vehicleHead > strong { color: var(--green); font: 700 34px Georgia, serif; }
.vehicleTrail.slow .vehicleHead > strong { color: var(--orange); }
.vehicleHead > strong span { color: #7b837f; font: 600 11px "PingFang SC", sans-serif; }
.tripScroller { padding: 28px 4px 4px; overflow-x: auto; scrollbar-color: rgba(24,75,59,.25) transparent; }
.tripSegments { width: max-content; min-width: 100%; display: flex; align-items: flex-start; gap: 24px; }
.tripLeg { flex: 0 0 auto; min-width: 96px; }
.tripLabels { display: grid; grid-template-columns: auto 1fr auto; align-items: center; gap: 5px; }
.tripLabels b { width: 24px; height: 24px; display: grid; place-items: center; color: white; background: var(--ink); border-radius: 50%; font: 700 10px Georgia, serif; z-index: 2; }
.tripLabels span { color: #747d78; text-align: center; font-size: 9px; white-space: nowrap; }
.tripLine { height: 5px; margin: 12px 12px 24px; position: relative; background: var(--green); border-radius: 999px; }
.slow .tripLine { background: var(--orange); }
.tripLine::after { content: "›"; position: absolute; right: -5px; top: 50%; color: var(--green); font: 700 25px/1 Georgia, serif; transform: translateY(-55%); }
.slow .tripLine::after { color: var(--orange); }
.tripLeg.left .tripLine::after { content: "‹"; left: -5px; right: auto; }
.tripLine i { width: 10px; height: 10px; position: absolute; top: 50%; border: 2px solid var(--cream); border-radius: 50%; background: var(--yellow); box-shadow: 0 0 0 1px var(--orange); transform: translate(-50%,-50%); }
.tripLine i span { position: absolute; top: 13px; left: 50%; color: var(--orange); font: 700 10px Georgia, serif; transform: translateX(-50%); }
.trailNote { max-width: 1220px; margin: 14px auto 0; padding: 15px 19px; display: flex; align-items: center; gap: 15px; color: #69736e; background: rgba(255,255,255,.42); border: 1px solid var(--line); border-radius: 9px; font-size: 12px; }
.trailNote > span { padding: 6px 9px; color: white; background: var(--orange); border-radius: 4px; font: 700 11px Georgia, serif; white-space: nowrap; }
.trailNote p { margin: 0; line-height: 1.7; }

footer { min-height: 110px; padding: 30px max(5vw, 24px); display: flex; justify-content: space-between; align-items: center; color: rgba(255,255,255,.58); background: #0e1c17; font-size: 12px; }
footer span { color: var(--yellow); font-weight: 800; letter-spacing: .12em; }

@media (max-width: 900px) {
  .hero { min-height: 0; padding-bottom: 70px; }
  .heroGrid { margin-top: 55px; grid-template-columns: 1fr; }
  .problemCard { max-width: 650px; transform: none; }
  .sectionHeading { grid-template-columns: 1fr; gap: 15px; }
  .sectionHeading > p { max-width: 600px; }
  .reasonSection, .solutionSection, .calculatorSection { grid-template-columns: 1fr; }
  .trajectoryHeading { grid-template-columns: 1fr; gap: 16px; }
  .reasonSection { gap: 35px; }
  .calculatorSection { gap: 35px; }
  .calculatorSection > div:first-child { justify-self: start; }
  .ruleBox { grid-template-columns: 1fr; gap: 25px; }
  .ruleBox .formulaExplain { padding: 0; border: 0; }
}

@media (max-width: 640px) {
  .hero, .simSection, .methodSection, .reasonSection, .solutionSection, .calculatorSection, .trajectorySection { padding-left: 18px; padding-right: 18px; }
  .topbar { height: 70px; }
  .brand { font-size: 13px; }
  .navLink { display: none; }
  .heroGrid { margin-top: 42px; gap: 42px; }
  .hero h1 { font-size: 45px; }
  .lead { font-size: 15px; }
  .problemCard { padding: 34px 27px 29px; box-shadow: 11px 12px 0 rgba(0,0,0,.13); }
  .problemText { font-size: 21px; }
  .simSection, .methodSection, .reasonSection, .calculatorSection, .trajectorySection { padding-top: 72px; padding-bottom: 72px; }
  .sectionHeading h2, .reasonIntro h2, .solutionTitle h2, .calculatorSection h2, .trajectoryHeading h2 { font-size: 36px; }
  .simControls { flex-wrap: wrap; padding: 15px; }
  .simControls button { flex: 1; padding: 0 11px; white-space: nowrap; }
  .simControls .playButton { flex-basis: 100%; margin: 5px 0 0; }
  .roadStage { min-height: 240px; padding-left: 11%; padding-right: 11%; }
  .placeA { left: 11%; }
  .placeB { right: 11%; }
  .carIcon { font-size: 29px; }
  .liveStats { grid-template-columns: 1fr; }
  .liveStats div { min-height: 72px; border-right: 0; border-bottom: 1px solid var(--line); }
  .oddCards { grid-template-columns: 1fr; }
  .oddCards article.focusCard { transform: none; box-shadow: none; }
  .ruleBox { padding: 27px 24px; }
  .reasonSection { padding-top: 72px; padding-bottom: 72px; }
  .unfolded { padding: 34px 18px; }
  .unfoldedCount { flex-direction: column; }
  .solutionSection { padding: 0 18px 72px; }
  .solutionCard, .pitfallCard { padding: 30px 24px; }
  .solutionTitle { align-items: start; flex-direction: column; }
  .solutionTitle > span { order: 0; }
  .finalAnswer { align-items: flex-start; flex-wrap: wrap; }
  .finalAnswer strong { flex-basis: 100%; margin-left: 41px; }
  .calculator { grid-template-columns: 1fr; width: 100%; }
  .calculatorResult { grid-column: 1; }
  .calculatorResult strong { font-size: 42px; }
  .trailTabs { align-items: stretch; flex-wrap: wrap; }
  .trailTabs button { flex: 1; padding: 0 10px; white-space: nowrap; }
  .trailTabs > span { flex-basis: 100%; margin: 5px 0 0; padding: 8px 4px 2px; text-align: center; }
  .vehicleTrail { padding: 22px 18px 25px; }
  .vehicleHead > strong { font-size: 27px; }
  .trailNote { align-items: flex-start; }
  footer { align-items: flex-start; flex-direction: column; justify-content: center; gap: 8px; }
  footer p { margin: 0; }
}

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