:root {
  color-scheme: light;
  --bg: #f3f7fb;
  --surface: #ffffff;
  --surface-soft: #eef4ff;
  --surface-strong: #0f172a;
  --line: #d8e1ef;
  --text: #172033;
  --muted: #5f6b82;
  --primary: #005ac2;
  --primary-soft: #dceaff;
  --accent: #ffb703;
  --success: #1c8c5e;
  --danger: #d1495b;
  --shadow: 0 18px 40px rgba(15, 23, 42, 0.12);
  --radius-xl: 28px;
  --radius-lg: 22px;
  --radius-md: 16px;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Noto Sans JP", sans-serif;
  color: var(--text);
  background:
    radial-gradient(circle at top right, rgba(0, 90, 194, 0.14), transparent 26%),
    linear-gradient(180deg, #f8fbff 0%, var(--bg) 42%, #edf3f8 100%);
}

a {
  color: inherit;
  text-decoration: none;
}

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

.material-symbols-outlined {
  font-variation-settings: "FILL" 0, "wght" 500, "GRAD" 0, "opsz" 24;
  vertical-align: middle;
}

.shell {
  width: min(100%, 780px);
  margin: 0 auto;
  padding: 16px 16px 48px;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  backdrop-filter: blur(14px);
  background: rgba(248, 251, 255, 0.8);
  border-bottom: 1px solid rgba(216, 225, 239, 0.9);
}

.topbar-inner {
  width: min(100%, 780px);
  margin: 0 auto;
  padding: 12px 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 13px;
  font-weight: 700;
  color: var(--surface-strong);
}

.brand-mark {
  width: 38px;
  height: 38px;
  display: grid;
  place-items: center;
  border-radius: 14px;
  background: linear-gradient(135deg, #005ac2, #4f8cff);
  color: #fff;
}

.chip-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 10px 14px;
  border-radius: 999px;
  background: var(--surface);
  border: 1px solid var(--line);
  font-size: 12px;
  font-weight: 700;
  color: var(--primary);
  box-shadow: 0 8px 20px rgba(15, 23, 42, 0.05);
}

.hero {
  padding-top: 18px;
  display: grid;
  gap: 16px;
}

.card {
  background: var(--surface);
  border: 1px solid rgba(216, 225, 239, 0.95);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow);
}

.hero-card {
  overflow: hidden;
  background:
    linear-gradient(145deg, rgba(0, 90, 194, 0.95), rgba(15, 23, 42, 0.96)),
    var(--surface-strong);
  color: #fff;
}

.hero-body {
  padding: 22px 20px 24px;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 12px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.16);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.03em;
}

h1 {
  margin: 16px 0 10px;
  font-size: clamp(28px, 8vw, 42px);
  line-height: 1.2;
}

.hero-copy {
  margin: 0;
  color: rgba(255, 255, 255, 0.84);
  font-size: 16px;
  line-height: 1.8;
}

.meta-row {
  margin-top: 18px;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.meta-pill {
  padding: 8px 12px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.1);
  font-size: 13px;
  font-weight: 700;
}

.section {
  padding: 20px;
}

.section-title {
  margin: 0 0 16px;
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 20px;
}

.question-box {
  display: grid;
  gap: 14px;
}

.question-header {
  display: flex;
  align-items: start;
  justify-content: space-between;
  gap: 12px;
}

.question-label {
  margin: 0;
  font-size: 13px;
  font-weight: 700;
  color: var(--primary);
  letter-spacing: 0.05em;
}

.question-text {
  margin: 8px 0 0;
  font-size: 26px;
  line-height: 1.35;
  font-weight: 800;
}

.difficulty {
  flex-shrink: 0;
  padding: 8px 12px;
  border-radius: 14px;
  background: var(--surface-soft);
  color: var(--primary);
  font-size: 13px;
  font-weight: 700;
}

.choices {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  margin-top: 6px;
}

.choice {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 16px;
  border-radius: 18px;
  border: 1px solid var(--line);
  background: #f9fbff;
}

.choice-index {
  width: 34px;
  height: 34px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  background: #fff;
  border: 1px solid var(--line);
  font-weight: 800;
  color: var(--muted);
}

.choice.correct {
  border-color: rgba(28, 140, 94, 0.25);
  background: rgba(28, 140, 94, 0.08);
}

.choice.correct .choice-index {
  background: var(--success);
  color: #fff;
  border-color: transparent;
}

.choice-text {
  flex: 1;
  font-size: 18px;
  font-weight: 700;
}

.answer-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 14px;
  border-radius: 999px;
  background: rgba(28, 140, 94, 0.1);
  color: var(--success);
  font-size: 15px;
  font-weight: 800;
}

.explanation {
  margin: 0;
  color: var(--muted);
  line-height: 1.9;
  font-size: 16px;
}

.product-banner {
  position: relative;
  display: block;
  overflow: hidden;
  border-radius: 28px;
  border: 1px solid rgba(255, 183, 3, 0.28);
  background: linear-gradient(135deg, #fff8e8 0%, #ffffff 54%, #eef5ff 100%);
  box-shadow: var(--shadow);
  aspect-ratio: 16 / 11;
}

.banner-image {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
}

.banner-overlay {
  position: relative;
  z-index: 1;
  height: 100%;
  padding: 18px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 16px;
  background:
    linear-gradient(180deg, rgba(10, 14, 24, 0.12) 0%, rgba(10, 14, 24, 0.1) 42%, rgba(10, 14, 24, 0.1) 100%);
}

.banner-badge {
  position: absolute;
  top: 0;
  right: 0;
  transform: none;
  padding: 8px 10px;
  border-radius: 14px;
  background: #0f172a;
  color: #fff;
  font-size: 14px;
  line-height: 1.4;
  font-weight: 800;
  box-shadow: 0 12px 24px rgba(15, 23, 42, 0.18);
}

.banner-copy {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  height: 100%;
  width: 100%;
  align-items: flex-start;
}

.banner-label {
  margin: 0;
  font-size: 13px;
  font-weight: 800;
  color: rgba(255, 232, 184, 0.96);
  letter-spacing: 0.06em;
}

.banner-title {
  margin: 5px 0 0;
  font-size: 18px;
  line-height: 1.5;
  color: #ffffff;
  writing-mode: horizontal-tb;
  text-orientation: mixed;
}

.banner-text {
  margin: 0;
  font-size: 14px;
  line-height: 1.9;
  color: rgba(255, 255, 255, 0.88);
  writing-mode: horizontal-tb;
  text-orientation: mixed;
}

.cta-row,
.link-list {
  display: grid;
  gap: 10px;
}

.cta-row {
  grid-template-columns: repeat(2, minmax(0, 1fr));
  margin: 0;
}

.cta {
  display: inline-flex;
  justify-content: center;
  align-items: center;
  gap: 8px;
  min-height: 52px;
  padding: 14px 18px;
  border-radius: 18px;
  font-weight: 800;
  font-size: 14px;
  text-align: center;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.cta.primary {
  background: linear-gradient(135deg, #005ac2, #3d84ff);
  color: #fff;
  box-shadow: 0 14px 24px rgba(0, 90, 194, 0.28);
}

.cta.secondary {
  background: #fff;
  color: var(--primary);
  border: 1px solid var(--line);
}

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

.support-card {
  padding: 16px;
  border-radius: 20px;
  background: #f9fbff;
  border: 1px solid var(--line);
}

.support-card h3 {
  margin: 0 0 8px;
  font-size: 18px;
}

.support-card p {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--muted);
}

.link-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  padding: 15px 16px;
  border-radius: 18px;
  background: #f9fbff;
  border: 1px solid var(--line);
  font-size: 16px;
  font-weight: 700;
}

.link-item small {
  display: block;
  margin-top: 4px;
  font-weight: 500;
  color: var(--muted);
  font-size: 13px;
}

.footer-note {
  margin-top: 18px;
  text-align: center;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.8;
}

.site-footer {
  width: min(100%, 780px);
  margin: 0 auto;
  padding: 0 16px 48px;
}

.footer-card {
  overflow: hidden;
  border-radius: 28px;
  border: 1px solid rgba(216, 225, 239, 0.95);
  background:
    linear-gradient(135deg, rgba(0, 90, 194, 0.96), rgba(15, 23, 42, 0.96));
  box-shadow: var(--shadow);
  color: #fff;
}

.footer-cta {
  padding: 22px 20px;
  display: grid;
  gap: 16px;
}

.footer-cta b {
  display: block;
  font-size: 22px;
  line-height: 1.45;
}

.footer-cta span {
  display: block;
  margin-top: 8px;
  color: rgba(255, 255, 255, 0.82);
  font-size: 16px;
  line-height: 1.8;
}

.footer-meta {
  margin: 14px 0 0;
  text-align: center;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.8;
}

.footer-meta a {
  color: var(--muted);
}

@media (min-width: 720px) {
  .shell {
    padding-left: 20px;
    padding-right: 20px;
  }

  .section {
    padding: 24px;
  }

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

  .site-footer {
    padding-left: 20px;
    padding-right: 20px;
  }

  .footer-cta {
    grid-template-columns: minmax(0, 1fr) minmax(300px, 360px);
    align-items: center;
  }
}

@media (max-width: 460px) {
  .product-banner {
    aspect-ratio: 4 / 5;
  }

  .banner-copy {
    gap: 8px;
    margin-top: 56px;
  }

  .question-text {
    font-size: 22px;
  }
}