:root {
  --paper: oklch(96% 0.012 80);
  --paper-deep: oklch(93% 0.018 75);
  --ink: oklch(22% 0.02 60);
  --ink-soft: oklch(38% 0.02 60);
  --rule: oklch(70% 0.02 70);
  --accent-red: oklch(52% 0.19 25);
  --accent-navy: oklch(35% 0.09 260);
  --accent-gold: oklch(72% 0.13 80);

  --tag-kokugo: oklch(55% 0.16 25);
  --tag-sugaku: oklch(50% 0.14 250);
  --tag-gaikokugo: oklch(55% 0.13 150);
  --tag-rika: oklch(55% 0.15 190);
  --tag-chireki: oklch(58% 0.14 90);
  --tag-komin: oklch(52% 0.15 320);
  --tag-joho: oklch(55% 0.14 200);
  --tag-kyotsu: oklch(45% 0.05 60);

  --font-serif: "Zen Old Mincho", "Noto Serif JP", serif;
  --font-sans: "Noto Sans JP", sans-serif;

  --space-section: clamp(3rem, 2.4rem + 3vw, 6rem);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-sans);
  line-height: 1.75;
  background-image:
    repeating-linear-gradient(0deg, transparent, transparent 27px, oklch(88% 0.015 70 / 0.5) 28px),
    radial-gradient(ellipse at top left, oklch(98% 0.01 80) 0%, transparent 60%);
}

a { color: inherit; }

.wrap {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 1.25rem;
}

/* ---------- Header ---------- */
.site-header {
  padding: 1.1rem 0;
  border-bottom: 1px solid var(--rule);
}
.site-header .wrap {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
}
.brand {
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: 1.15rem;
  letter-spacing: 0.04em;
}
.brand small {
  display: block;
  font-family: var(--font-sans);
  font-weight: 400;
  font-size: 0.65rem;
  color: var(--ink-soft);
  letter-spacing: 0.1em;
}
.header-note {
  font-size: 0.72rem;
  color: var(--ink-soft);
}

/* ---------- Hero ---------- */
.hero {
  padding: clamp(2.5rem, 4vw, 5rem) 0 clamp(2rem, 3vw, 3rem);
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: "受験ノート";
  position: absolute;
  top: -0.4em;
  right: -0.3rem;
  font-family: var(--font-serif);
  font-size: clamp(4rem, 14vw, 9rem);
  font-weight: 700;
  color: oklch(90% 0.02 70);
  writing-mode: vertical-rl;
  z-index: 0;
  pointer-events: none;
  user-select: none;
}
.hero .wrap { position: relative; z-index: 1; }
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  color: var(--accent-red);
  margin-bottom: 1rem;
}
.eyebrow::before {
  content: "";
  width: 1.6rem;
  height: 1px;
  background: var(--accent-red);
}
h1.hero-title {
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: clamp(2rem, 5.5vw, 3.4rem);
  line-height: 1.35;
  margin: 0 0 1rem;
  max-width: 14ch;
}
h1.hero-title em {
  font-style: normal;
  color: var(--accent-red);
  border-bottom: 3px solid var(--accent-gold);
}
.hero-lead {
  font-size: 1rem;
  color: var(--ink-soft);
  max-width: 46ch;
  margin: 0 0 1.75rem;
}
.hero-stats {
  display: flex;
  gap: clamp(1.25rem, 3vw, 2.5rem);
  flex-wrap: wrap;
  border-top: 1px solid var(--rule);
  padding-top: 1.25rem;
}
.hero-stats div { min-width: 6rem; }
.hero-stats .num {
  font-family: var(--font-serif);
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--accent-navy);
  display: block;
}
.hero-stats .label {
  font-size: 0.72rem;
  color: var(--ink-soft);
}

/* ---------- Section headings ---------- */
.section {
  padding: var(--space-section) 0 0;
}
.section-head {
  display: flex;
  align-items: baseline;
  gap: 0.9rem;
  margin-bottom: 1.5rem;
}
.section-head .idx {
  font-family: var(--font-serif);
  font-size: 0.85rem;
  color: var(--accent-red);
  border: 1px solid var(--accent-red);
  border-radius: 50%;
  width: 1.9rem;
  height: 1.9rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}
.section-head h2 {
  font-family: var(--font-serif);
  font-size: clamp(1.3rem, 2.6vw, 1.7rem);
  margin: 0;
}
.section-lead {
  color: var(--ink-soft);
  font-size: 0.9rem;
  max-width: 60ch;
  margin: 0 0 1.75rem;
}

/* ---------- Bento grid: flagship apps ---------- */
.bento {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 1rem;
}
.card {
  background: oklch(99% 0.005 80);
  border: 1px solid var(--rule);
  border-radius: 4px;
  padding: 1.25rem;
  position: relative;
  box-shadow: 3px 3px 0 oklch(85% 0.02 70 / 0.6);
  transition: transform 0.18s var(--ease, cubic-bezier(0.16,1,0.3,1)), box-shadow 0.18s;
  display: flex;
  flex-direction: column;
  gap: 0.7rem;
}
.card:hover {
  transform: translate(-2px, -3px);
  box-shadow: 6px 7px 0 oklch(80% 0.03 70 / 0.55);
}
.card.flagship {
  grid-column: span 3;
  padding: 1.75rem;
}
.card.rank-1 { grid-column: span 3; }
.card.rank-2 { grid-column: span 3; }

.card-top {
  display: flex;
  align-items: flex-start;
  gap: 0.9rem;
}
.card-icon {
  width: 56px;
  height: 56px;
  border-radius: 12px;
  object-fit: cover;
  flex-shrink: 0;
  border: 1px solid var(--rule);
}
.card.flagship .card-icon { width: 72px; height: 72px; border-radius: 16px; }
.rank-badge {
  font-family: var(--font-serif);
  font-size: 0.65rem;
  color: var(--accent-navy);
  letter-spacing: 0.08em;
}
.card-name {
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: 1.15rem;
  margin: 0.15rem 0 0;
  line-height: 1.4;
}
.card.flagship .card-name { font-size: 1.4rem; }
.card-audience {
  display: inline-block;
  font-size: 0.68rem;
  color: var(--ink-soft);
  border: 1px solid var(--rule);
  border-radius: 99px;
  padding: 0.1rem 0.6rem;
  margin-top: 0.3rem;
}
.card-desc {
  font-size: 0.85rem;
  color: var(--ink-soft);
  margin: 0;
  flex-grow: 1;
}
.card-links {
  display: flex;
  gap: 0.6rem;
  margin-top: 0.4rem;
  flex-wrap: wrap;
}
.store-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.76rem;
  font-weight: 700;
  text-decoration: none;
  padding: 0.5rem 0.85rem;
  border-radius: 6px;
  border: 1.5px solid var(--ink);
  transition: background 0.15s, color 0.15s;
}
.store-btn.apple { background: var(--ink); color: var(--paper); }
.store-btn.apple:hover { background: var(--accent-red); border-color: var(--accent-red); }
.store-btn.google { background: transparent; color: var(--ink); }
.store-btn.google:hover { background: var(--ink); color: var(--paper); }
.store-btn:focus-visible { outline: 2px solid var(--accent-red); outline-offset: 2px; }

.pending-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.76rem;
  font-weight: 700;
  padding: 0.5rem 0.85rem;
  border-radius: 6px;
  border: 1.5px dashed var(--ink-soft);
  color: var(--ink-soft);
}

/* ---------- Subject tab grid (8-subject series) ---------- */
.subject-intro {
  background: var(--paper-deep);
  border: 1px solid var(--rule);
  border-radius: 4px;
  padding: 1.25rem 1.5rem;
  margin-bottom: 1.5rem;
  display: flex;
  gap: 1rem;
  align-items: center;
}
.subject-intro img { width: 60px; height: 60px; border-radius: 14px; flex-shrink: 0; border: 1px solid var(--rule); }
.subject-intro p { margin: 0; font-size: 0.85rem; color: var(--ink-soft); }
.subject-intro strong { font-family: var(--font-serif); font-size: 1.05rem; color: var(--ink); display: block; margin-bottom: 0.2rem; }

.subject-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0.75rem;
}
.subject-card {
  background: oklch(99% 0.005 80);
  border: 1px solid var(--rule);
  border-top: 4px solid var(--tag);
  border-radius: 3px;
  padding: 0.9rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}
.subject-card .tag-label {
  font-size: 0.65rem;
  font-weight: 700;
  color: var(--tag);
  letter-spacing: 0.05em;
}
.subject-card .card-icon { width: 40px; height: 40px; border-radius: 9px; }
.subject-card .card-top { gap: 0.6rem; align-items: center; }
.subject-card .card-name { font-size: 0.92rem; margin: 0; }
.subject-card .card-desc { font-size: 0.76rem; }
.subject-card .card-links { gap: 0.4rem; }
.subject-card .store-btn { font-size: 0.68rem; padding: 0.35rem 0.6rem; }
.subject-card .pending-badge { font-size: 0.68rem; padding: 0.35rem 0.6rem; }

.s-kokugo { --tag: var(--tag-kokugo); }
.s-sugaku { --tag: var(--tag-sugaku); }
.s-gaikokugo { --tag: var(--tag-gaikokugo); }
.s-rika { --tag: var(--tag-rika); }
.s-chireki { --tag: var(--tag-chireki); }
.s-komin { --tag: var(--tag-komin); }
.s-joho { --tag: var(--tag-joho); }
.s-kyotsu { --tag: var(--tag-kyotsu); }

/* ---------- Junior series ---------- */
.junior-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
}

/* ---------- Footer ---------- */
.site-footer {
  margin-top: var(--space-section);
  border-top: 1px solid var(--rule);
  padding: 2rem 0 3rem;
  font-size: 0.78rem;
  color: var(--ink-soft);
}
.site-footer .footer-brand {
  font-family: var(--font-serif);
  color: var(--ink);
  font-weight: 700;
  margin-bottom: 0.5rem;
}
.footer-legal {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem 0.9rem;
  margin-top: 1.25rem;
  padding-top: 1.25rem;
  border-top: 1px dashed var(--rule);
}
.footer-legal a { text-decoration: underline; text-underline-offset: 2px; }

/* ---------- Responsive ---------- */
@media (max-width: 860px) {
  .bento { grid-template-columns: 1fr; }
  .card.flagship, .card.rank-1, .card.rank-2 { grid-column: span 1; }
  .subject-grid { grid-template-columns: repeat(2, 1fr); }
  .junior-grid { grid-template-columns: 1fr; }
}
@media (max-width: 480px) {
  .subject-grid { grid-template-columns: 1fr; }
  .subject-intro { flex-direction: column; align-items: flex-start; }
  .hero::before { display: none; }
}