:root {
  --ink: #1d2140;
  --ink-soft: #545a7a;
  --brand: #2f3a8f;
  --brand-2: #6c4cd8;
  --sun: #ffb84d;
  --bg: #fffdf8;
  --bg-alt: #f4f2fb;
  --line: #e6e3f0;
  --radius: 20px;
  --shadow: 0 10px 30px rgba(47, 58, 143, 0.10);
  --font: "Hiragino Maru Gothic ProN", "Hiragino Sans", "Noto Sans JP", "Yu Gothic UI", "Meiryo", system-ui, sans-serif;
}

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

html { scroll-behavior: smooth; scroll-padding-top: 72px; }

body {
  margin: 0;
  font-family: var(--font);
  color: var(--ink);
  background: var(--bg);
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; height: auto; display: block; }
a { color: inherit; }
h1, h2, h3 { line-height: 1.4; margin: 0 0 .5em; text-wrap: balance; }

.container { width: min(1120px, 100% - 40px); margin-inline: auto; }
.narrow { width: min(760px, 100% - 40px); }
.pc-only { display: none; }

/* Buttons */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: .4em;
  min-height: 44px; padding: .85em 1.6em; border-radius: 999px; font-weight: 700;
  text-decoration: none; border: 2px solid transparent;
  transition: transform .15s ease, box-shadow .15s ease, background .15s ease;
}
.btn:hover { transform: translateY(-2px); }
.btn:focus-visible { outline: 3px solid var(--sun); outline-offset: 2px; }
.btn-primary { background: var(--brand); color: #fff; box-shadow: 0 6px 18px rgba(47,58,143,.3); }
.btn-ghost { border-color: var(--brand); color: var(--brand); background: #fff; }
.btn-small { padding: .5em 1.2em; min-height: 44px; background: var(--brand); color: #fff; font-size: .9rem; }
.btn-light { background: #fff; color: var(--brand); }

/* Header */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255, 253, 248, .9);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}
.header-inner { display: flex; align-items: center; justify-content: space-between; height: 64px; }
.logo { display: inline-flex; align-items: center; gap: .5em; font-weight: 800; font-size: 1.3rem; text-decoration: none; color: var(--brand); letter-spacing: .02em; }

.menu-toggle {
  display: flex; flex-direction: column; gap: 5px; justify-content: center;
  width: 44px; height: 44px; padding: 10px; border: 0; background: transparent; cursor: pointer;
}
.menu-toggle span { display: block; height: 2px; background: var(--ink); border-radius: 2px; transition: transform .2s, opacity .2s; }
.menu-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.menu-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.menu-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

.site-nav {
  position: absolute; top: 64px; left: 0; right: 0;
  display: none; flex-direction: column; gap: .25rem;
  padding: 1rem 20px 1.5rem; background: var(--bg); border-bottom: 1px solid var(--line);
  box-shadow: var(--shadow);
}
.site-nav.open { display: flex; }
.site-nav a { text-decoration: none; font-weight: 700; padding: .6em 0; }
.site-nav .btn-small { margin-top: .5rem; padding: .7em; }

/* Hero */
.hero {
  background:
    radial-gradient(circle at 85% 20%, rgba(108,76,216,.16), transparent 45%),
    radial-gradient(circle at 10% 90%, rgba(255,184,77,.22), transparent 40%);
  padding: 3rem 0 4rem;
  overflow: hidden;
}
.hero-inner { display: grid; gap: 2.5rem; align-items: center; }
.eyebrow {
  display: inline-block; margin: 0 0 .8rem; padding: .25em .9em;
  font-size: .8rem; font-weight: 800; letter-spacing: .08em;
  color: var(--brand-2); background: #efeaff; border-radius: 999px;
}
.hero h1 { font-size: clamp(1.7rem, 6.5vw, 3.2rem); font-weight: 900; letter-spacing: .01em; }
.lead { font-size: 1.05rem; color: var(--ink-soft); }
.lead strong { color: var(--ink); background: linear-gradient(transparent 60%, rgba(255,184,77,.5) 60%); }
.hero-actions { display: flex; flex-wrap: wrap; gap: .8rem; margin: 1.6rem 0; }
.hero-points { list-style: none; padding: 0; margin: 0; display: flex; flex-wrap: wrap; gap: .5rem 1.2rem; font-size: 1rem; color: var(--ink-soft); }
.hero-points li::before { content: "✓"; color: var(--brand-2); font-weight: 900; margin-right: .35em; }

.hero-visual { display: flex; justify-content: center; }
.hero-visual img { width: min(360px, 80vw); }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation: none !important; transition: none !important; }
  html { scroll-behavior: auto; }
}

/* Sections */
.section { padding: 4.5rem 0; }
.section-alt { background: var(--bg-alt); }
.section-head { text-align: center; margin-bottom: 2.5rem; }
.section-head.left { text-align: left; margin-bottom: 1.5rem; }
.section-head h2 { font-size: clamp(1.6rem, 4.5vw, 2.2rem); font-weight: 900; }
.section-head p:last-child:not(.eyebrow) { color: var(--ink-soft); margin: 0; }

/* Worries */
.worries { list-style: none; margin: 0; padding: 0; display: grid; gap: .8rem; }
.worries li {
  display: flex; align-items: center; gap: .9rem;
  background: #fff; border: 1px solid var(--line); border-radius: 14px; padding: 1rem 1.2rem; font-weight: 700;
}
.worry-icon { flex: none; width: 44px; height: 44px; display: grid; place-items: center; font-size: 1.5rem; background: var(--bg-alt); border-radius: 12px; }
.worries-close { margin: 2rem 0 0; text-align: center; font-size: 1.15rem; font-weight: 800; color: var(--brand); }

/* Cards */
.cards { display: grid; gap: 1.5rem; }
.card {
  display: flex; flex-direction: column;
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 1.75rem; box-shadow: var(--shadow);
  border-top: 6px solid var(--accent);
  transition: transform .2s ease, box-shadow .2s ease;
}
.card:hover { transform: translateY(-4px); box-shadow: 0 16px 40px rgba(47,58,143,.15); }
.card-icon {
  width: 64px; height: 64px; display: grid; place-items: center;
  font-size: 2rem; border-radius: 18px; background: var(--accent-soft); margin-bottom: 1rem;
}
.card-body { flex: 1; }
.card-tag { margin: 0 0 .3rem; font-size: .8rem; font-weight: 800; color: var(--accent); }
.card h3 { font-size: 1.45rem; font-weight: 900; margin-bottom: .2rem; }
.card h3 .sub { font-size: .8rem; font-weight: 700; color: var(--ink-soft); margin-left: .3em; }
.card-catch { font-weight: 800; margin: 0 0 .6rem; }
.card-worry { font-size: .95rem; color: var(--ink-soft); background: var(--accent-soft); border-radius: 10px; padding: .5rem .8rem; }
.card-wizlearn { --accent: #6c4cd8; --accent-soft: #efeaff; }
.card-readstar { --accent: #c24a22; --accent-soft: #fdeee7; }
.card-mathme { --accent: #17705a; --accent-soft: #e3f6ef; }
.card-homequest { --accent: #8a5d00; --accent-soft: #fff4dc; }
.card p { margin-top: 0; }
.card-features { list-style: none; padding: 0; margin: 0 0 1.5rem; }
.card-features li { padding-left: 1.4em; position: relative; }
.card-features li::before { content: "●"; position: absolute; left: 0; color: var(--accent); font-size: .7em; top: .3em; }
.btn-card { width: 100%; background: var(--accent); color: #fff; }
.btn-card.is-disabled { background: #e6e3f0; color: var(--ink-soft); cursor: not-allowed; pointer-events: none; box-shadow: none; }
.note { margin-top: 2rem; font-size: .875rem; color: var(--ink-soft); text-align: center; }

/* About */
.about-body p { color: var(--ink-soft); }
.values { display: grid; gap: 1rem; margin-top: 2rem; }
.value { background: #fff; border-radius: var(--radius); padding: 1.4rem; border: 1px solid var(--line); }
.value-icon { font-size: 1.8rem; }
.value h3 { font-size: 1.1rem; margin: .4rem 0 .2rem; }
.value p { margin: 0; }

/* Safety */
.safety-grid { display: grid; gap: 1rem; }
.safety-item { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 1.4rem; }
.safety-item h3 { font-size: 1.1rem; margin: 0 0 .4rem; }
.safety-item p { margin: 0; color: var(--ink-soft); }
.safety-item a { color: var(--brand); font-weight: 700; margin-left: .3em; }

/* Steps */
.steps { list-style: none; margin: 0; padding: 0; display: grid; gap: 1rem; }
.steps li { display: flex; gap: 1rem; align-items: flex-start; background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 1.2rem 1.4rem; }
.step-num { flex: none; width: 44px; height: 44px; display: grid; place-items: center; border-radius: 50%; background: var(--brand); color: #fff; font-weight: 900; font-size: 1.2rem; }
.steps h3 { font-size: 1.1rem; margin: 0 0 .2rem; }
.steps p { margin: 0; color: var(--ink-soft); }

/* FAQ */
details {
  background: #fff; border: 1px solid var(--line); border-radius: 14px;
  padding: 0 1.2rem; margin-bottom: .8rem;
}
summary {
  cursor: pointer; font-weight: 800; padding: 1rem 2rem 1rem 0; position: relative; list-style: none;
}
summary::-webkit-details-marker { display: none; }
summary::after {
  content: "+"; position: absolute; right: 0; top: 50%; transform: translateY(-50%);
  font-size: 1.4rem; color: var(--brand-2); transition: transform .2s;
}
details[open] summary::after { transform: translateY(-50%) rotate(45deg); }
details p { margin: 0 0 1rem; color: var(--ink-soft); }

/* CTA */
.cta { background: linear-gradient(135deg, var(--brand), var(--brand-2)); color: #fff; padding: 4rem 0; text-align: center; }
.cta h2 { font-size: clamp(1.4rem, 4.5vw, 2rem); font-weight: 900; }
.cta p { opacity: .9; margin-bottom: 1.8rem; }

/* Footer */
.site-footer { background: var(--ink); color: #c9cbe0; padding: 3rem 0 1.5rem; }
.footer-inner { display: grid; gap: 1.5rem; }
.logo-footer { color: #fff; }
.footer-tag { margin: .3rem 0 0; font-size: .9rem; }
.footer-nav { display: flex; flex-wrap: wrap; gap: .5rem 1.5rem; }
.footer-links { display: grid; gap: 1rem; }
.footer-nav a { text-decoration: none; font-size: 1rem; display: inline-flex; align-items: center; min-height: 44px; }
.footer-nav a:hover { color: #fff; }
.copyright { text-align: center; font-size: .8rem; margin: 2.5rem 0 0; opacity: .7; }

/* Prose pages (privacy / about) */
.prose h1 { font-size: clamp(1.6rem, 5vw, 2.2rem); font-weight: 900; }
.prose h2 { font-size: 1.2rem; margin: 2rem 0 .5rem; padding-left: .7em; border-left: 5px solid var(--brand-2); }
.prose p, .prose li, .prose dd { color: var(--ink-soft); }
.prose a { color: var(--brand); font-weight: 700; }
.prose .meta { font-size: .875rem; }
.info { display: grid; gap: .3rem 1.5rem; margin: 1.5rem 0; }
.info dt { font-weight: 800; margin-top: .8rem; }
.info dd { margin: 0; }
.is-disabled { pointer-events: none; opacity: .6; }

.notfound { min-height: 100vh; display: grid; place-items: center; text-align: center; }
.notfound img { margin: 0 auto 1.5rem; }
.notfound p { color: var(--ink-soft); }
.notfound .btn { margin: .5rem .3rem 0; }

/* Tablet */
@media (min-width: 640px) {
  .cards { grid-template-columns: repeat(2, 1fr); }
  .values { grid-template-columns: repeat(3, 1fr); }
  .info { grid-template-columns: 8em 1fr; }
  .info dt { margin-top: 0; }
  .safety-grid { grid-template-columns: repeat(2, 1fr); }
}

/* Desktop */
@media (min-width: 960px) {
  .pc-only { display: inline; }
  .menu-toggle { display: none; }
  .site-nav {
    position: static; display: flex; flex-direction: row; align-items: center; gap: 1.8rem;
    padding: 0; background: none; border: 0; box-shadow: none;
  }
  .site-nav a:not(.btn) { font-size: .95rem; }
  .site-nav a:not(.btn):hover { color: var(--brand-2); }
  .site-nav .btn-small { margin: 0; padding: .5em 1.3em; }

  .hero { padding: 5rem 0 6rem; }
  .hero-inner { grid-template-columns: 1.2fr 1fr; }

  .about { display: grid; grid-template-columns: 1fr 2fr; gap: 3rem; }
  .footer-inner { grid-template-columns: 1fr auto; align-items: start; }
}