:root {
  --navy-950: #08142c;
  --navy-900: #0c1b3a;
  --navy-800: #122750;
  --navy-700: #173b74;
  --blue-600: #2563eb;
  --blue-100: #eaf2ff;
  --red-600: #c92b25;
  --yellow-400: #facc15;
  --yellow-300: #fde047;
  --green-600: #16824b;
  --ink: #172033;
  --muted: #58657a;
  --line: #dce3ed;
  --tint: #f4f7fb;
  --white: #ffffff;
  --shadow: 0 18px 45px rgba(8, 20, 44, 0.1);
  --radius: 20px;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--white);
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "Hiragino Kaku Gothic ProN", "Yu Gothic", Meiryo, sans-serif;
  font-size: 16px;
  line-height: 1.7;
  overflow-x: hidden;
  text-rendering: optimizeLegibility;
}

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

a {
  color: inherit;
}

a:focus-visible,
button:focus-visible,
summary:focus-visible {
  outline: 3px solid #5b9dff;
  outline-offset: 4px;
}

.container {
  width: min(100% - 32px, 1160px);
  margin-inline: auto;
}

.site-header {
  position: relative;
  z-index: 20;
  height: 64px;
  background: var(--navy-950);
  border-bottom: 1px solid rgba(255, 255, 255, 0.12);
}

.site-header-inner {
  width: min(100% - 28px, 1200px);
  height: 100%;
  margin-inline: auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.brand-link {
  display: inline-flex;
  align-items: center;
  flex: 0 0 auto;
}

.brand-link img {
  display: block;
  width: 142px;
}

.header-nav {
  display: flex;
  align-items: center;
  gap: 16px;
  font-size: 0.82rem;
  font-weight: 700;
}

.header-nav a {
  color: #fff;
  text-decoration: none;
}

.header-join-link {
  display: none;
}

.header-login-link {
  padding: 7px 14px;
  border: 1px solid rgba(255, 255, 255, 0.5);
  border-radius: 999px;
}

.header-nav a:hover {
  text-decoration: underline;
  text-underline-offset: 4px;
}

.site-notice-area {
  width: min(100% - 24px, 980px);
  margin: 16px auto 0;
}

.hero {
  position: relative;
  min-height: calc(100svh - 64px);
  display: flex;
  align-items: center;
  color: #fff;
  background:
    radial-gradient(circle at 85% 18%, rgba(37, 99, 235, 0.32), transparent 32%),
    linear-gradient(145deg, var(--navy-950), var(--navy-800));
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  inset: auto -30% -210px 20%;
  height: 300px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.035);
  transform: rotate(-7deg);
}

.hero-inner {
  position: relative;
  z-index: 1;
  width: min(100% - 32px, 1160px);
  margin-inline: auto;
  padding: 44px 0 52px;
}

.hero-content {
  max-width: 720px;
}

.section-kicker {
  margin: 0 0 12px;
  color: var(--red-600);
  font-size: 0.74rem;
  font-weight: 900;
  letter-spacing: 0.13em;
  text-transform: uppercase;
}

.hero h1 {
  margin: 0;
  color: #fff;
  font-size: clamp(2.25rem, 10.2vw, 4.25rem);
  line-height: 1.17;
  letter-spacing: -0.035em;
  text-wrap: balance;
}

.hero-lead {
  margin: 18px 0 0;
  color: #dbe6fa;
  font-size: clamp(0.98rem, 3.8vw, 1.2rem);
  line-height: 1.75;
}

.hero-points {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 16px;
  margin: 18px 0 0;
  padding: 0;
  list-style: none;
  color: #fff;
  font-size: 0.79rem;
  font-weight: 700;
}

.hero-points i {
  color: var(--yellow-300);
  margin-right: 4px;
}

.hero-actions,
.final-actions {
  display: grid;
  gap: 10px;
  margin-top: 24px;
}

.button {
  min-height: 48px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  padding: 12px 20px;
  border: 2px solid transparent;
  border-radius: 999px;
  font-size: 0.95rem;
  font-weight: 900;
  line-height: 1.25;
  text-align: center;
  text-decoration: none;
  transition: transform 0.18s ease, box-shadow 0.18s ease, background-color 0.18s ease;
}

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

.button-primary {
  color: #111827;
  background: var(--yellow-400);
  box-shadow: 0 12px 30px rgba(250, 204, 21, 0.18);
}

.button-primary:hover {
  background: var(--yellow-300);
  box-shadow: 0 15px 34px rgba(250, 204, 21, 0.25);
}

.button-light {
  color: var(--navy-900);
  background: #fff;
  border-color: #fff;
}

.button-ghost {
  color: #fff;
  background: transparent;
  border-color: rgba(255, 255, 255, 0.55);
}

.button-ghost:hover {
  background: rgba(255, 255, 255, 0.08);
}

.hero-visual {
  display: none;
}

.section {
  padding: 72px 0;
}

.section-white {
  background: #fff;
}

.section-tint {
  background: var(--tint);
}

.section-heading {
  max-width: 760px;
  margin: 0 auto 38px;
  text-align: center;
}

.section-heading h2,
.demo-band h2,
.final-cta h2 {
  margin: 0;
  color: var(--navy-900);
  font-size: clamp(1.75rem, 7.2vw, 2.75rem);
  line-height: 1.3;
  letter-spacing: -0.025em;
  text-wrap: balance;
}

.section-heading > p:last-child {
  margin: 13px auto 0;
  color: var(--muted);
  line-height: 1.75;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.feature-card {
  min-width: 0;
  padding: 20px 15px;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: #fff;
}

.icon-box,
.step-icon,
.usecase-icon {
  width: 44px;
  height: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex: 0 0 auto;
  border-radius: 13px;
  color: var(--red-600);
  background: #fff3f1;
  font-size: 1.12rem;
}

.feature-card h3 {
  margin: 13px 0 6px;
  color: var(--navy-900);
  font-size: 0.98rem;
  line-height: 1.45;
}

.feature-card p {
  margin: 0;
  color: var(--muted);
  font-size: 0.84rem;
  line-height: 1.65;
}

.flow-list {
  display: grid;
  gap: 12px;
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: flow;
}

.flow-list li {
  position: relative;
  min-width: 0;
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 0 15px;
  align-items: center;
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fff;
}

.step-number {
  position: absolute;
  top: 12px;
  right: 15px;
  color: #dbe4f2;
  font-size: 1.3rem;
  font-weight: 900;
  line-height: 1;
}

.step-icon {
  grid-row: 1 / span 2;
  color: var(--blue-600);
  background: var(--blue-100);
}

.flow-list h3 {
  margin: 0;
  color: var(--navy-900);
  font-size: 1rem;
}

.flow-list p {
  margin: 3px 0 0;
  color: var(--muted);
  font-size: 0.88rem;
}

.no-install-callout {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  max-width: 820px;
  margin: 24px auto 0;
  padding: 18px;
  border: 1px solid #f1cf39;
  border-radius: 16px;
  color: var(--navy-900);
  background: #fff9d9;
}

.no-install-callout > i {
  margin-top: 4px;
  color: #b46b00;
  font-size: 1.25rem;
}

.no-install-callout strong,
.no-install-callout span {
  display: block;
}

.no-install-callout strong {
  font-size: 0.95rem;
  line-height: 1.5;
}

.no-install-callout span {
  margin-top: 3px;
  color: #6b5313;
  font-size: 0.82rem;
}

.demo-band {
  padding: 48px 0;
  color: #fff;
  background: linear-gradient(115deg, var(--navy-900), var(--navy-700));
}

.demo-band-inner {
  display: grid;
  gap: 25px;
  text-align: center;
}

.demo-band .section-kicker,
.section-heading-light .section-kicker,
.final-cta .section-kicker {
  color: var(--yellow-300);
}

.demo-band h2 {
  color: #fff;
  font-size: clamp(1.5rem, 6.5vw, 2.3rem);
}

.demo-band p:not(.section-kicker) {
  margin: 10px 0 0;
  color: #dbe6fa;
}

.demo-band .button {
  width: min(100%, 300px);
  margin-inline: auto;
}

.usecase-grid {
  display: grid;
  gap: 12px;
}

.usecase-card {
  display: flex;
  gap: 16px;
  min-width: 0;
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fff;
}

.usecase-icon {
  color: var(--navy-700);
  background: #eef3fa;
}

.usecase-card h3 {
  margin: 0 0 5px;
  color: var(--navy-900);
  font-size: 1.04rem;
}

.usecase-card p {
  margin: 0;
  color: var(--muted);
  font-size: 0.88rem;
}

.event-types {
  color: #fff;
  background: var(--navy-950);
}

.section-heading-light h2 {
  color: #fff;
}

.section-heading-light > p:last-child {
  color: #c6d4ec;
}

.event-type-grid {
  display: grid;
  gap: 16px;
}

.event-type-card {
  min-width: 0;
  padding: 26px 22px;
  border: 1px solid rgba(255, 255, 255, 0.16);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.07);
}

.event-type-card::before {
  content: "";
  display: block;
  width: 46px;
  height: 4px;
  margin-bottom: 20px;
  border-radius: 999px;
  background: var(--yellow-400);
}

.bingo-type-card::before {
  background: #4ade80;
}

.event-type-label {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  color: var(--yellow-300);
  font-size: 0.77rem;
  font-weight: 900;
  letter-spacing: 0.12em;
}

.bingo-type-card .event-type-label {
  color: #86efac;
}

.event-type-card h3 {
  margin: 10px 0 8px;
  font-size: 1.4rem;
  line-height: 1.4;
}

.event-type-card > p {
  margin: 0;
  color: #c6d4ec;
  font-size: 0.91rem;
}

.check-list {
  display: grid;
  gap: 9px;
  margin: 22px 0 0;
  padding: 0;
  list-style: none;
  font-size: 0.9rem;
  font-weight: 700;
}

.check-list li {
  display: flex;
  gap: 10px;
}

.check-list li::before {
  content: "✓";
  color: var(--yellow-300);
  font-weight: 900;
}

.bingo-type-card .check-list li::before {
  color: #86efac;
}

.benefit-grid {
  display: grid;
  gap: 16px;
}

.benefit-card {
  min-width: 0;
  padding: 24px 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fff;
  box-shadow: 0 10px 30px rgba(8, 20, 44, 0.05);
}

.benefit-heading {
  display: flex;
  align-items: center;
  gap: 14px;
  padding-bottom: 18px;
  border-bottom: 1px solid var(--line);
}

.benefit-heading > span {
  width: 50px;
  height: 50px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  color: #fff;
  background: var(--navy-700);
  font-size: 1.2rem;
}

.player-benefit .benefit-heading > span {
  background: var(--green-600);
}

.benefit-heading small {
  color: var(--muted);
  font-size: 0.68rem;
  font-weight: 900;
  letter-spacing: 0.12em;
}

.benefit-heading h3 {
  margin: 0;
  color: var(--navy-900);
  font-size: 1.28rem;
}

.benefit-list {
  display: grid;
  gap: 14px;
  margin: 20px 0 0;
  padding: 0;
  list-style: none;
}

.benefit-list li {
  display: flex;
  align-items: flex-start;
  gap: 11px;
  color: #354158;
  font-size: 0.91rem;
}

.benefit-list i {
  width: 21px;
  height: 21px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex: 0 0 auto;
  margin-top: 3px;
  border-radius: 50%;
  color: #fff;
  background: var(--blue-600);
  font-size: 0.58rem;
}

.player-benefit .benefit-list i {
  background: var(--green-600);
}

.faq-container {
  max-width: 900px;
}

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

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

.faq-list summary {
  position: relative;
  padding: 20px 44px 20px 4px;
  color: var(--navy-900);
  font-weight: 800;
  line-height: 1.5;
  cursor: pointer;
  list-style: none;
}

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

.faq-list summary::after {
  content: "+";
  position: absolute;
  top: 50%;
  right: 7px;
  width: 28px;
  height: 28px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  color: #fff;
  background: var(--navy-700);
  font-size: 1.1rem;
  transform: translateY(-50%);
}

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

.faq-list details > div {
  padding: 0 4px 20px;
  color: var(--muted);
  font-size: 0.92rem;
}

.faq-list p {
  margin: 0;
}

.faq-list a {
  color: #154fba;
  font-weight: 700;
  text-underline-offset: 3px;
}

.final-cta {
  padding: 74px 0;
  color: #fff;
  text-align: center;
  background:
    radial-gradient(circle at 20% 20%, rgba(37, 99, 235, 0.3), transparent 30%),
    linear-gradient(145deg, var(--navy-950), var(--navy-800));
}

.final-cta-inner {
  max-width: 850px;
}

.final-cta h2 {
  color: #fff;
}

.final-cta-inner > p:not(.section-kicker) {
  margin: 16px auto 0;
  color: #dbe6fa;
}

.final-actions {
  max-width: 680px;
  margin: 28px auto 0;
}

.final-login-link {
  display: inline-block;
  margin-top: 19px;
  color: #fff;
  font-size: 0.86rem;
  font-weight: 700;
  text-underline-offset: 4px;
}

.site-footer {
  padding: 34px 0;
  color: #aebbd0;
  background: #060d1e;
}

.footer-inner {
  display: grid;
  justify-items: center;
  gap: 22px;
  text-align: center;
}

.footer-brand img {
  display: block;
  width: 135px;
}

.footer-nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px 18px;
  font-size: 0.78rem;
}

.footer-nav a {
  text-decoration: none;
}

.footer-nav a:hover {
  color: #fff;
  text-decoration: underline;
  text-underline-offset: 4px;
}

.site-footer small {
  font-size: 0.72rem;
}

@media (min-width: 560px) {
  .header-join-link {
    display: inline;
  }

  .hero-actions,
  .final-actions {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .hero-actions .button-ghost {
    grid-column: 1 / -1;
  }

  .usecase-grid,
  .benefit-grid,
  .event-type-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .mobile-break {
    display: none;
  }
}

@media (min-width: 760px) {
  .container {
    width: min(100% - 48px, 1160px);
  }

  .site-header {
    height: 72px;
  }

  .brand-link img {
    width: 170px;
  }

  .header-nav {
    gap: 24px;
    font-size: 0.9rem;
  }

  .hero {
    min-height: calc(100svh - 72px);
  }

  .hero-inner {
    width: min(100% - 48px, 1160px);
    padding: 72px 0 82px;
  }

  .hero-actions {
    max-width: 680px;
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .hero-actions .button-ghost {
    grid-column: auto;
  }

  .section {
    padding: 96px 0;
  }

  .section-heading {
    margin-bottom: 50px;
  }

  .feature-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 16px;
  }

  .feature-card {
    padding: 25px 21px;
  }

  .feature-card h3 {
    font-size: 1.02rem;
  }

  .flow-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 16px;
  }

  .demo-band {
    padding: 58px 0;
  }

  .demo-band-inner {
    grid-template-columns: 1fr auto;
    align-items: center;
    text-align: left;
  }

  .demo-band .button {
    min-width: 250px;
  }

  .usecase-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 16px;
  }

  .event-type-grid,
  .benefit-grid {
    gap: 22px;
  }

  .event-type-card,
  .benefit-card {
    padding: 34px;
  }

  .final-actions {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 980px) {
  .hero-inner {
    display: grid;
    grid-template-columns: minmax(0, 1.18fr) minmax(380px, 0.82fr);
    gap: 28px;
    align-items: center;
  }

  .hero-content {
    max-width: none;
  }

  .hero h1 {
    font-size: clamp(2.85rem, 4.4vw, 3.75rem);
  }

  .hero-title-line {
    white-space: nowrap;
  }

  .hero-visual {
    position: relative;
    min-height: 475px;
    display: block;
  }

  .visual-glow {
    position: absolute;
    inset: 12% 0 0 4%;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(44, 107, 224, 0.43), transparent 66%);
    filter: blur(4px);
  }

  .device {
    position: absolute;
    width: 280px;
    padding: 11px;
    border: 1px solid rgba(255, 255, 255, 0.26);
    border-radius: 25px;
    color: var(--ink);
    background: #f8fafc;
    box-shadow: 0 30px 55px rgba(0, 0, 0, 0.35);
  }

  .device-quiz {
    top: 6px;
    left: 0;
    transform: rotate(-3deg);
  }

  .device-bingo {
    right: 0;
    bottom: 0;
    width: 260px;
    padding: 10px;
    border-radius: 16px;
    background: #fff7dc;
    transform: rotate(3deg);
  }

  .device-bar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 4px 3px 10px;
    color: var(--navy-900);
    font-size: 0.62rem;
    letter-spacing: 0.08em;
  }

  .device-bar > span:first-child {
    width: 42px;
    height: 5px;
    border-radius: 999px;
    background: #cbd5e1;
  }

  .live-dot {
    color: #b91c1c;
    font-weight: 900;
  }

  .quiz-question {
    min-height: 104px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: 7px;
    padding: 16px;
    border-radius: 15px;
    color: #fff;
    background: var(--navy-800);
  }

  .quiz-question small {
    color: var(--yellow-300);
    font-weight: 900;
  }

  .answer-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 7px;
    margin-top: 8px;
  }

  .answer-grid span {
    padding: 11px 8px;
    border: 1px solid #dbe4ef;
    border-radius: 10px;
    background: #fff;
    font-size: 0.66rem;
    font-weight: 800;
  }

  .answer-grid span:first-child {
    border: 2px solid #f59e0b;
    background: #fffbeb;
  }

  .reaction-row {
    display: flex;
    align-items: center;
    gap: 6px;
    margin-top: 9px;
    padding: 8px 10px;
    border-radius: 11px;
    background: #e8eef8;
  }

  .reaction-row small {
    margin-left: auto;
    color: var(--navy-700);
    font-weight: 900;
  }

  .bingo-card {
    padding: 7px;
    border: 3px solid #d69b16;
    border-radius: 12px;
    background: #fffdf5;
    box-shadow: inset 0 0 0 1px #f6d77b;
  }

  .bingo-letters,
  .bingo-numbers {
    display: grid;
    grid-template-columns: repeat(5, minmax(0, 1fr));
    gap: 3px;
  }

  .bingo-letters {
    margin-bottom: 4px;
  }

  .bingo-letters span {
    display: grid;
    place-items: center;
    min-height: 25px;
    border-radius: 5px;
    color: #fff;
    font-size: 0.88rem;
    font-weight: 1000;
    line-height: 1;
    text-shadow: 0 1px 1px rgba(0, 0, 0, 0.24);
  }

  .bingo-letters .is-b { background: #dc2626; }
  .bingo-letters .is-i { background: #2563eb; }
  .bingo-letters .is-n { background: #16824b; }
  .bingo-letters .is-g { background: #d97706; }
  .bingo-letters .is-o { background: #7c3aed; }

  .bingo-numbers span {
    aspect-ratio: 1;
    display: grid;
    place-items: center;
    position: relative;
    border: 1px solid #e4c66f;
    border-radius: 4px;
    color: var(--navy-900);
    background: #fff;
    font-size: 0.72rem;
    font-weight: 1000;
    line-height: 1;
  }

  .bingo-numbers .is-marked,
  .bingo-numbers .is-free {
    color: #fff;
    background: var(--green-600);
    border-color: #0f6b3c;
    border-radius: 50%;
    box-shadow: inset 0 0 0 2px rgba(255, 255, 255, 0.32);
  }

  .bingo-numbers .is-free {
    gap: 1px;
    background: #d69b16;
    border-color: #b7790b;
  }

  .bingo-numbers .is-free i {
    font-size: 0.54rem;
  }

  .bingo-numbers .is-free small {
    font-size: 0.35rem;
    font-weight: 1000;
    line-height: 1;
  }

  .flow-list {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .flow-list li {
    display: block;
    padding: 26px 22px;
  }

  .step-icon {
    width: 50px;
    height: 50px;
    margin-bottom: 18px;
  }

  .flow-list li:not(:last-child)::after {
    content: "";
    position: absolute;
    top: 50px;
    right: -19px;
    z-index: 2;
    width: 22px;
    height: 2px;
    background: #aebed4;
  }
}

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

  *,
  *::before,
  *::after {
    transition-duration: 0.01ms !important;
  }
}