:root {
  --ink: #18212b;
  --muted: #5b6675;
  --line: #dce5ec;
  --paper: #f7faf8;
  --white: #ffffff;
  --blue: #1769e0;
  --teal: #12a6a6;
  --green: #1f9b6d;
  --red: #e24b4b;
  --yellow: #f4bd3e;
  --shadow: 0 18px 45px rgba(24, 33, 43, 0.12);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background:
    linear-gradient(180deg, #e9f7fb 0, rgba(233, 247, 251, 0) 520px),
    var(--paper);
  font-family: "Noto Sans JP", system-ui, sans-serif;
  line-height: 1.75;
}

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

a {
  color: inherit;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 14px clamp(18px, 4vw, 56px);
  background: rgba(247, 250, 248, 0.92);
  border-bottom: 1px solid rgba(220, 229, 236, 0.9);
  backdrop-filter: blur(14px);
}

.brand,
.header-nav {
  display: flex;
  align-items: center;
  gap: 12px;
}

.brand {
  font-weight: 900;
  text-decoration: none;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 34px;
  height: 34px;
  color: var(--white);
  background: var(--ink);
  border-radius: 8px;
}

.header-nav a {
  color: var(--muted);
  font-size: 14px;
  font-weight: 900;
  text-decoration: none;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(280px, 440px);
  align-items: center;
  gap: clamp(28px, 6vw, 76px);
  max-width: 1180px;
  min-height: calc(100vh - 86px);
  margin: 0 auto;
  padding: clamp(42px, 8vw, 96px) clamp(18px, 4vw, 40px) 34px;
}

.eyebrow {
  margin: 0 0 10px;
  color: var(--teal);
  font-size: 13px;
  font-weight: 900;
  letter-spacing: 0;
}

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

h1 {
  max-width: 760px;
  margin-bottom: 18px;
  font-size: clamp(40px, 7vw, 72px);
  line-height: 1.08;
  letter-spacing: 0;
}

h2 {
  margin-bottom: 12px;
  font-size: clamp(28px, 4vw, 44px);
  line-height: 1.18;
}

h3 {
  margin-bottom: 8px;
  font-size: 19px;
  line-height: 1.35;
}

.lead {
  max-width: 660px;
  margin-bottom: 28px;
  color: var(--muted);
  font-size: clamp(16px, 2vw, 20px);
  font-weight: 500;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 12px 18px;
  border: 1px solid transparent;
  border-radius: 8px;
  font-weight: 900;
  text-decoration: none;
  transition: transform 0.18s ease, box-shadow 0.18s ease;
}

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

.primary {
  color: var(--white);
  background: var(--blue);
  box-shadow: 0 12px 28px rgba(23, 105, 224, 0.24);
}

.secondary {
  color: var(--ink);
  background: var(--white);
  border-color: var(--line);
}

.hero-panel {
  display: grid;
  gap: 18px;
  justify-items: center;
}

.penguin {
  width: min(100%, 350px);
  filter: drop-shadow(0 24px 34px rgba(24, 33, 43, 0.16));
}

.quick-codes {
  display: grid;
  width: min(100%, 390px);
  overflow: hidden;
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.quick-codes div {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 12px 16px;
}

.quick-codes div + div {
  border-top: 1px solid var(--line);
}

.quick-codes span {
  color: var(--muted);
  font-size: 13px;
  font-weight: 900;
}

.quick-codes strong {
  overflow-wrap: anywhere;
  font-size: 18px;
}

.notice-band,
.summary-grid,
.service-section,
.notes,
.sources {
  max-width: 1120px;
  margin: 0 auto;
}

.notice-band {
  display: flex;
  gap: 12px;
  margin-bottom: 24px;
  padding: 16px 18px;
  color: #493b12;
  background: #fff6d8;
  border: 1px solid #f0d680;
  border-radius: 8px;
}

.summary-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
  padding: 24px clamp(18px, 4vw, 40px) 18px;
}

.summary-card {
  display: grid;
  gap: 3px;
  min-height: 140px;
  padding: 20px;
  background: var(--white);
  border: 1px solid var(--line);
  border-top: 6px solid var(--teal);
  border-radius: 8px;
  text-decoration: none;
  box-shadow: 0 12px 28px rgba(24, 33, 43, 0.08);
}

.summary-card:nth-child(1) {
  border-top-color: var(--blue);
}

.summary-card:nth-child(2) {
  border-top-color: var(--red);
}

.summary-card:nth-child(3) {
  border-top-color: var(--green);
}

.summary-card span,
.summary-card small,
.code-box span,
figcaption {
  color: var(--muted);
  font-size: 12px;
  font-weight: 900;
}

.summary-card strong {
  font-size: 26px;
  line-height: 1.15;
}

.service-section {
  margin-top: 28px;
  padding: clamp(28px, 5vw, 52px) clamp(18px, 4vw, 40px);
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.service-section + .service-section {
  margin-top: 24px;
}

.service-header {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(260px, 330px);
  gap: 24px;
  align-items: start;
  margin-bottom: 30px;
}

.service-header p {
  max-width: 760px;
  color: var(--muted);
}

.code-box {
  display: grid;
  gap: 10px;
  padding: 18px;
  background: #f6fafb;
  border: 1px solid var(--line);
  border-radius: 8px;
}

.code-box strong {
  overflow-wrap: anywhere;
  font-size: 30px;
  line-height: 1.1;
}

.promo-card {
  display: grid;
  gap: 12px;
  margin-bottom: 26px;
  padding: 22px;
  color: var(--ink);
  background: #f7fbff;
  border: 2px solid rgba(23, 105, 224, 0.18);
  border-radius: 8px;
}

.promo-card h3 {
  margin-bottom: 0;
  font-size: clamp(24px, 3vw, 34px);
  line-height: 1.22;
}

.promo-card p {
  max-width: 920px;
  margin-bottom: 0;
  color: var(--muted);
}

.promo-label {
  display: inline-flex;
  width: fit-content;
  padding: 5px 10px;
  color: var(--white);
  background: var(--blue);
  border-radius: 6px;
  font-size: 12px;
  font-weight: 900;
}

.rocket-promo {
  background: #fff8f7;
  border-color: rgba(226, 75, 75, 0.24);
}

.rocket-promo .promo-label {
  background: var(--red);
}

.menu-promo {
  background: #f4fbf6;
  border-color: rgba(31, 155, 109, 0.24);
}

.menu-promo .promo-label {
  background: var(--green);
}

.reward-list {
  display: grid;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.reward-list li {
  padding: 10px 12px;
  color: var(--muted);
  background: rgba(255, 255, 255, 0.72);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.reward-list strong {
  color: var(--ink);
}

.copy-button {
  min-height: 44px;
  border: 0;
  border-radius: 8px;
  color: var(--white);
  background: var(--ink);
  font: inherit;
  font-weight: 900;
  cursor: pointer;
}

.content-layout {
  display: grid;
  grid-template-columns: minmax(280px, 0.9fr) minmax(0, 1.1fr);
  gap: 24px;
  align-items: start;
}

.content-layout.reverse {
  grid-template-columns: minmax(0, 1.1fr) minmax(280px, 0.9fr);
}

.content-layout.reverse .official-visual {
  order: 2;
}

.official-visual {
  margin: 0;
  padding: 14px;
  background: #f7fafb;
  border: 1px solid var(--line);
  border-radius: 8px;
}

.official-visual img {
  width: 100%;
  max-height: 360px;
  object-fit: contain;
  background: var(--white);
  border-radius: 6px;
}

figcaption {
  margin-top: 10px;
}

.info-blocks {
  display: grid;
  gap: 14px;
}

.info-blocks article {
  padding: 18px;
  background: #fbfcfd;
  border: 1px solid var(--line);
  border-radius: 8px;
}

.info-blocks p,
.info-blocks li,
.notes li,
.sources p {
  color: var(--muted);
}

ol {
  margin: 0;
  padding-left: 1.35em;
}

.link-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.link-list a {
  display: inline-flex;
  align-items: center;
  min-height: 40px;
  padding: 8px 12px;
  color: var(--ink);
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 8px;
  font-size: 14px;
  font-weight: 900;
  text-decoration: none;
}

.bitflyer-section {
  border-top: 7px solid var(--blue);
}

.rocket-section {
  border-top: 7px solid var(--red);
}

.menu-section {
  border-top: 7px solid var(--green);
}

.notes,
.sources {
  margin-top: 24px;
  padding: clamp(26px, 5vw, 42px) clamp(18px, 4vw, 40px);
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 8px;
}

.notes {
  display: grid;
  grid-template-columns: 0.4fr 1fr;
  gap: 26px;
}

.notes ul {
  margin: 0;
  padding-left: 1.2em;
}

.notes li + li {
  margin-top: 10px;
}

.sources {
  margin-bottom: 42px;
}

.sources h2 {
  font-size: 26px;
}

.site-footer {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  padding: 24px clamp(18px, 4vw, 56px);
  color: var(--muted);
  border-top: 1px solid var(--line);
}

.site-footer p {
  margin: 0;
}

.toast {
  position: fixed;
  left: 50%;
  bottom: 20px;
  z-index: 20;
  padding: 10px 16px;
  color: var(--white);
  background: var(--ink);
  border-radius: 8px;
  opacity: 0;
  transform: translate(-50%, 12px);
  transition: opacity 0.2s ease, transform 0.2s ease;
  pointer-events: none;
}

.toast.show {
  opacity: 1;
  transform: translate(-50%, 0);
}

@media (max-width: 920px) {
  .hero,
  .summary-grid,
  .service-header,
  .content-layout,
  .content-layout.reverse,
  .notes {
    grid-template-columns: 1fr;
  }

  .hero {
    min-height: auto;
  }

  .hero-panel {
    order: -1;
  }

  .content-layout.reverse .official-visual {
    order: 0;
  }
}

@media (max-width: 640px) {
  .site-header {
    align-items: flex-start;
    flex-direction: column;
  }

  .header-nav {
    width: 100%;
    justify-content: space-between;
    gap: 8px;
  }

  .header-nav a {
    font-size: 12px;
  }

  .notice-band {
    align-items: flex-start;
    flex-direction: column;
    margin-inline: 18px;
  }

  .quick-codes div {
    align-items: flex-start;
    flex-direction: column;
    gap: 2px;
  }

  .service-section,
  .notes,
  .sources {
    border-radius: 0;
    border-left: 0;
    border-right: 0;
  }

  .code-box strong {
    font-size: 26px;
  }
}