:root {
  --white: #ffffff;
  --aqua: #00c2d1;
  --pink: #ff3d77;
  --gold: #ffc736;
  --ink: #23253a;
  --ink-soft: #656778;
  --line: rgba(35, 37, 58, 0.14);
  --page: min(1120px, calc(100% - 40px));
  --reading: min(760px, calc(100% - 40px));
  --radius-sm: 10px;
  --radius-md: 18px;
  --shadow-soft: 0 20px 58px rgba(35, 37, 58, 0.1);
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  text-size-adjust: 100%;
}

body {
  min-width: 320px;
  margin: 0;
  color: var(--ink);
  background: var(--white);
  font-family: "Hiragino Sans", "Yu Gothic", "YuGothic", "Noto Sans JP", system-ui, sans-serif;
  font-size: 16px;
  line-height: 1.85;
  -webkit-font-smoothing: antialiased;
}

img {
  display: block;
  max-width: 100%;
  height: auto;
}

a {
  color: inherit;
  text-decoration-thickness: 1px;
  text-underline-offset: 0.22em;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1,
h2,
h3 {
  font-weight: 650;
  line-height: 1.28;
  letter-spacing: 0;
}

:focus-visible {
  outline: 3px solid rgba(0, 194, 209, 0.32);
  outline-offset: 4px;
}

.skip-link {
  position: fixed;
  z-index: 100;
  top: 12px;
  left: 12px;
  padding: 8px 14px;
  background: var(--ink);
  color: var(--white);
  border-radius: var(--radius-sm);
  transform: translateY(-160%);
}

.skip-link:focus {
  transform: translateY(0);
}

.site-header {
  height: 72px;
  border-bottom: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.95);
}

.site-header__inner {
  width: var(--page);
  height: 100%;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 20px;
  font-weight: 700;
  white-space: nowrap;
  text-decoration: none;
}

.brand__coin {
  display: grid;
  width: 34px;
  height: 34px;
  place-items: center;
  color: var(--ink);
  background: var(--gold);
  border: 1px solid rgba(35, 37, 58, 0.16);
  border-radius: 50%;
  font-size: 15px;
}

.header-link {
  color: var(--ink-soft);
  font-size: 14px;
  text-decoration: none;
}

.button {
  min-height: 52px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 13px 24px;
  border: 1px solid transparent;
  border-radius: 999px;
  font-weight: 700;
  line-height: 1.3;
  text-align: center;
  text-decoration: none;
  transition:
    transform 180ms ease,
    box-shadow 180ms ease,
    background-color 180ms ease;
}

.button:hover {
  transform: translateY(-2px);
}

.button--primary {
  color: var(--white);
  background: var(--pink);
  box-shadow: 0 12px 26px rgba(255, 61, 119, 0.2);
}

.button--text {
  min-height: auto;
  padding: 8px 0;
  color: var(--aqua);
  border-radius: 0;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 12px;
  color: var(--aqua);
  font-size: 13px;
  font-weight: 700;
}

.eyebrow::before {
  width: 28px;
  height: 1px;
  content: "";
  background: currentColor;
}

.hero {
  border-bottom: 1px solid var(--line);
}

.hero__inner {
  width: var(--page);
  min-height: calc(100svh - 72px);
  margin: 0 auto;
  display: grid;
  gap: 28px;
  align-items: center;
  padding: 42px 0 34px;
}

.hero__copy {
  max-width: 610px;
}

.hero h1 {
  margin-bottom: 18px;
  font-size: clamp(48px, 14vw, 92px);
  line-height: 1.02;
}

.hero__lead {
  max-width: 520px;
  margin-bottom: 26px;
  color: var(--ink-soft);
  font-size: clamp(17px, 4.8vw, 22px);
  line-height: 1.7;
}

.hero__product {
  position: relative;
  min-height: 450px;
  display: grid;
  place-items: center;
}

.hero__mascot {
  position: absolute;
  right: clamp(0px, 5vw, 54px);
  bottom: 4px;
  width: clamp(96px, 22vw, 168px);
  filter: drop-shadow(0 16px 18px rgba(35, 37, 58, 0.12));
}

.phone-frame {
  width: min(100%, 340px);
  margin: 0;
  padding: 10px;
  border: 1px solid rgba(35, 37, 58, 0.16);
  border-radius: 28px;
  background: var(--white);
  box-shadow: var(--shadow-soft);
}

.phone-frame img {
  width: 100%;
  border-radius: 20px;
}

.phone-frame--hero {
  width: min(72vw, 360px);
  max-height: min(72svh, 620px);
  overflow: hidden;
}

.phone-frame--small {
  width: min(46vw, 235px);
  justify-self: end;
  margin-top: -34px;
}

.proof,
.receipt,
.steps,
.final-cta {
  width: var(--page);
  margin: 0 auto;
  padding: 86px 0;
  border-bottom: 1px solid var(--line);
}

.proof {
  display: grid;
  gap: 32px;
  align-items: center;
}

.proof__copy {
  max-width: 560px;
}

.proof h2,
.receipt h2,
.steps h2,
.final-cta h2 {
  margin-bottom: 0;
  font-size: clamp(30px, 8vw, 54px);
}

.proof__seesaw {
  display: grid;
  gap: 16px;
  align-items: end;
}

.seesawStage {
  position: relative;
  width: min(100%, 620px);
  aspect-ratio: 3 / 2;
  margin: 0 auto;
  --tilt-deg: 0deg;
  --coin-b: 0;
}

.seesawFulcrum {
  position: absolute;
  left: 50%;
  bottom: 0;
  z-index: 0;
  width: 32%;
  height: auto;
  transform: translateX(-50%);
  pointer-events: none;
}

.seesawBeam {
  position: absolute;
  z-index: 1;
  top: 50%;
  right: 0;
  left: 0;
  transform: translateY(-50%) rotate(var(--tilt-deg));
  transform-origin: 50% 50%;
  transition: transform 260ms cubic-bezier(0.22, 1, 0.36, 1);
}

.seesawPlank {
  display: block;
  width: 100%;
  height: auto;
  pointer-events: none;
}

.seesawSeat {
  position: absolute;
  bottom: 30%;
  width: 34%;
}

.seesawSeat--left {
  left: 2%;
}

.seesawSeat--right {
  right: 2%;
}

.seesawPlate {
  display: block;
  width: 100%;
  height: auto;
  pointer-events: none;
}

.seesawRider {
  position: absolute;
  bottom: 44%;
  left: 50%;
  font-size: clamp(24px, 7vw, 34px);
  line-height: 1;
  transform: translateX(-50%) rotate(calc(-1 * var(--tilt-deg)));
  transform-origin: 50% 100%;
  transition: transform 260ms cubic-bezier(0.22, 1, 0.36, 1);
  filter: drop-shadow(0 3px 4px rgba(35, 37, 58, 0.16));
}

.seesawCoin {
  position: absolute;
  top: 44%;
  left: calc(50% + var(--coin-b, 0) * 32%);
  z-index: 2;
  width: 18%;
  height: auto;
  transform: translateX(-50%) rotate(calc(-1 * var(--tilt-deg)));
  transition:
    left 320ms cubic-bezier(0.22, 1, 0.36, 1),
    transform 320ms cubic-bezier(0.22, 1, 0.36, 1);
  pointer-events: none;
}

.seesawSparkle {
  position: absolute;
  top: 4%;
  right: 10%;
  z-index: 3;
  width: 14%;
  height: auto;
  opacity: 0.7;
  pointer-events: none;
}

.seesawStage--auto .seesawBeam {
  animation: lp-seesaw-beam 6.5s ease-in-out infinite;
}

.seesawStage--auto .seesawRider,
.seesawStage--auto .seesawCoin {
  animation: lp-seesaw-counter 6.5s ease-in-out infinite;
}

.seesawStage--auto .seesawCoin {
  animation-name: lp-seesaw-coin;
}

.receipt {
  display: grid;
  gap: 32px;
  align-items: start;
}

.receipt__copy {
  max-width: 580px;
}

.receipt__image {
  max-height: 680px;
  margin: 0;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-soft);
}

.receipt__image img {
  width: 100%;
}

.steps {
  position: relative;
  display: grid;
  gap: 28px;
  overflow: hidden;
}

.steps__inner {
  max-width: 760px;
}

.steps__list {
  display: grid;
  gap: 0;
  margin-top: 28px;
  border-top: 1px solid var(--line);
}

.steps__list p {
  margin: 0;
  padding: 18px 0;
  border-bottom: 1px solid var(--line);
  color: var(--ink-soft);
}

.steps__mascot {
  width: min(54vw, 240px);
  justify-self: end;
}

.faq-list {
  border-top: 1px solid var(--line);
}

.faq-list details {
  border-bottom: 1px solid var(--line);
}

.faq-list summary {
  position: relative;
  padding: 24px 42px 24px 0;
  cursor: pointer;
  font-weight: 700;
  list-style: none;
}

.faq-list summary::-webkit-details-marker {
  display: none;
}

.faq-list summary::after {
  position: absolute;
  top: 23px;
  right: 4px;
  color: var(--aqua);
  content: "+";
  font-size: 24px;
  font-weight: 400;
}

.faq-list details[open] summary::after {
  content: "-";
}

.faq-list details p {
  max-width: 760px;
  padding: 0 0 24px;
  margin: 0;
  color: var(--ink-soft);
}

.section {
  width: var(--page);
  margin: 0 auto;
  padding: 86px 0;
  border-bottom: 1px solid var(--line);
}

.section__inner {
  width: 100%;
}

.section__heading {
  max-width: 690px;
  margin-bottom: 32px;
}

.section h2 {
  margin-bottom: 0;
  font-size: clamp(30px, 8vw, 50px);
}

.guide-links {
  display: grid;
  border-top: 1px solid var(--line);
}

.guide-link {
  display: grid;
  gap: 4px;
  padding: 20px 0;
  border-bottom: 1px solid var(--line);
  text-decoration: none;
}

.guide-link:hover {
  color: var(--aqua);
}

.guide-link small {
  color: var(--ink-soft);
}

.final-cta {
  text-align: left;
}

.final-cta p {
  max-width: 560px;
  margin: 14px 0 24px;
  color: var(--ink-soft);
}

.site-footer {
  padding: 42px 0;
  background: var(--white);
}

.site-footer__inner {
  width: var(--page);
  margin: 0 auto;
  display: grid;
  gap: 22px;
}

.footer-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 18px;
  color: var(--ink-soft);
  font-size: 13px;
}

.copyright {
  margin: 0;
  color: var(--ink-soft);
  font-size: 12px;
}

.article-header {
  padding: 58px 0 46px;
  border-bottom: 1px solid var(--line);
}

.article-header__inner {
  width: var(--reading);
  margin: 0 auto;
}

.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 28px;
  color: var(--ink-soft);
  font-size: 12px;
}

.article-header h1 {
  max-width: 700px;
  margin-bottom: 18px;
  font-size: clamp(34px, 9vw, 58px);
}

.article-lead {
  max-width: 680px;
  margin-bottom: 0;
  color: var(--ink-soft);
  font-size: 17px;
}

.article-meta {
  margin-top: 18px;
  color: var(--ink-soft);
  font-size: 12px;
}

.article-body {
  width: var(--reading);
  margin: 0 auto;
  padding: 54px 0 86px;
}

.article-body h2 {
  margin: 54px 0 16px;
  padding-top: 6px;
  font-size: clamp(26px, 7vw, 36px);
}

.article-body h3 {
  margin: 32px 0 10px;
  font-size: 21px;
}

.article-body p,
.article-body li {
  line-height: 2;
}

.article-body ul,
.article-body ol {
  padding-left: 1.35em;
}

.article-body li + li {
  margin-top: 8px;
}

.article-cta {
  margin: 34px 0;
  padding: 24px 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.article-cta h2,
.article-cta h3 {
  margin: 0 0 8px;
  padding: 0;
  font-size: 24px;
}

.article-cta p {
  margin-bottom: 18px;
  line-height: 1.8;
  color: var(--ink-soft);
}

.example-table {
  width: 100%;
  margin: 24px 0;
  border-collapse: collapse;
  font-size: 14px;
}

.example-table caption {
  margin-bottom: 10px;
  text-align: left;
  font-weight: 700;
}

.example-table th,
.example-table td {
  padding: 12px 10px;
  border-bottom: 1px solid var(--line);
  text-align: left;
  vertical-align: top;
}

.example-table th {
  font-weight: 700;
}

.callout {
  margin: 30px 0;
  padding: 18px 0 18px 18px;
  border-left: 3px solid var(--aqua);
}

.callout p:last-child {
  margin-bottom: 0;
}

.related-guides {
  margin-top: 60px;
  padding-top: 30px;
  border-top: 1px solid var(--line);
}

.related-guides h2 {
  margin-top: 0;
}

.related-guides__list {
  display: grid;
  gap: 12px;
}

.related-guides__list a {
  padding: 16px 0;
  border-bottom: 1px solid var(--line);
  color: var(--aqua);
  font-weight: 700;
}

@keyframes lp-seesaw-beam {
  0%,
  100% {
    transform: translateY(-50%) rotate(-8deg);
  }
  50% {
    transform: translateY(-50%) rotate(7deg);
  }
}

@keyframes lp-seesaw-counter {
  0%,
  100% {
    transform: translateX(-50%) rotate(8deg);
  }
  50% {
    transform: translateX(-50%) rotate(-7deg);
  }
}

@keyframes lp-seesaw-coin {
  0%,
  100% {
    left: calc(50% - 10.2%);
    transform: translateX(-50%) rotate(8deg);
  }
  50% {
    left: calc(50% + 9%);
    transform: translateX(-50%) rotate(-7deg);
  }
}

@media (min-width: 720px) {
  :root {
    --page: min(1120px, calc(100% - 72px));
    --reading: min(760px, calc(100% - 72px));
  }

  .hero__inner {
    grid-template-columns: minmax(0, 0.9fr) minmax(350px, 0.82fr);
    padding: 34px 0 30px;
  }

  .hero__product {
    min-height: 620px;
  }

  .proof--left {
    grid-template-columns: minmax(0, 0.86fr) minmax(300px, 0.72fr);
  }

  .proof--right {
    grid-template-columns: minmax(300px, 0.92fr) minmax(0, 0.76fr);
  }

  .proof--right .proof__copy {
    order: 2;
  }

  .proof--right .proof__seesaw {
    order: 1;
  }

  .proof--left .phone-frame {
    justify-self: end;
  }

  .receipt {
    grid-template-columns: minmax(0, 0.78fr) minmax(360px, 0.8fr);
  }

  .steps {
    grid-template-columns: minmax(0, 1fr) 260px;
    align-items: end;
  }

  .guide-links {
    grid-template-columns: 1fr 1fr;
    column-gap: 42px;
  }

  .site-footer__inner {
    grid-template-columns: auto 1fr;
    align-items: start;
  }

  .copyright {
    grid-column: 1 / -1;
  }

  .related-guides__list {
    grid-template-columns: 1fr 1fr;
    gap: 28px;
  }
}

@media (max-width: 560px) {
  :root {
    --page: calc(100% - 28px);
    --reading: calc(100% - 28px);
  }

  .site-header {
    height: 64px;
  }

  .header-link {
    display: none;
  }

  .hero__inner {
    min-height: calc(100svh - 64px);
    padding-top: 34px;
  }

  .hero__product {
    min-height: 410px;
  }

  .phone-frame--hero {
    width: min(78vw, 300px);
  }

  .phone-frame--small {
    width: min(58vw, 210px);
  }

  .proof,
  .receipt,
  .steps,
  .section,
  .final-cta {
    padding: 70px 0;
  }

  .button {
    width: 100%;
  }

  .article-header {
    padding-top: 42px;
  }

  .article-body {
    padding-top: 42px;
  }

  .article-cta {
    padding: 22px 0;
  }

  .example-table {
    font-size: 12px;
  }

  .example-table th,
  .example-table td {
    padding: 10px 7px;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}