/* ============================================================
   BENKYO LEARN — Design System
   Aesthetic: Japanese Minimalism meets Tech
   ============================================================ */

@import url('https://fonts.googleapis.com/css2?family=Noto+Serif+JP:wght@300;400;700&family=Noto+Sans+JP:wght@300;400;500&family=Space+Mono:wght@400;700&display=swap');

:root {
  --ink:        #1a1a1a;
  --washi:      #f5f0e8;
  --bamboo:     #4a7c59;
  --sumi:       #2d2d2d;
  --vermilion:  #c0392b;
  --gold:       #b8860b;
  --mist:       #e8e4dc;
  --shadow:     rgba(26,26,26,0.08);

  --font-serif: 'Noto Serif JP', serif;
  --font-sans:  'Noto Sans JP', sans-serif;
  --font-mono:  'Space Mono', monospace;

  --radius: 2px;
  --transition: 0.3s ease;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  background: var(--washi);
  color: var(--ink);
  font-family: var(--font-sans);
  font-weight: 300;
  line-height: 1.8;
  font-size: 16px;
  overflow-x: hidden;
}

/* ── TYPOGRAPHY ─────────────────────────────────────────── */
h1, h2, h3, h4 {
  font-family: var(--font-serif);
  font-weight: 700;
  line-height: 1.3;
  letter-spacing: -0.02em;
}
h1 { font-size: clamp(2rem, 5vw, 4rem); }
h2 { font-size: clamp(1.5rem, 3vw, 2.5rem); }
h3 { font-size: 1.25rem; }

p { margin-bottom: 1rem; }

a {
  color: var(--bamboo);
  text-decoration: none;
  transition: color var(--transition);
}
a:hover { color: var(--vermilion); }

.mono { font-family: var(--font-mono); font-size: 0.85em; }

/* ── NAVIGATION ─────────────────────────────────────────── */
nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  background: rgba(245,240,232,0.92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--mist);
  padding: 0 2rem;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  font-family: var(--font-serif);
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--ink);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}
.nav-logo .kanji {
  font-size: 1.5rem;
  color: var(--vermilion);
  line-height: 1;
}

.nav-links {
  display: flex;
  gap: 2rem;
  list-style: none;
}
.nav-links a {
  color: var(--sumi);
  font-size: 0.85rem;
  font-weight: 400;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  position: relative;
}
.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -3px; left: 0;
  width: 0; height: 1px;
  background: var(--vermilion);
  transition: width var(--transition);
}
.nav-links a:hover::after { width: 100%; }
.nav-links a:hover { color: var(--ink); }

.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  flex-direction: column;
  gap: 5px;
}
.nav-toggle span {
  display: block;
  width: 24px; height: 1px;
  background: var(--ink);
  transition: var(--transition);
}

/* ── MAIN LAYOUT ────────────────────────────────────────── */
main { padding-top: 64px; }

.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 2rem;
}

section { padding: 6rem 0; }

/* ── HERO ───────────────────────────────────────────────── */
.hero {
  min-height: 92vh;
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
  padding: 0;
}

.hero::before {
  content: '勉強';
  position: absolute;
  right: -0.1em;
  top: 50%;
  transform: translateY(-50%);
  font-family: var(--font-serif);
  font-size: clamp(12rem, 25vw, 22rem);
  font-weight: 700;
  color: rgba(26,26,26,0.04);
  line-height: 1;
  pointer-events: none;
  user-select: none;
}

.hero-content {
  position: relative;
  z-index: 1;
  max-width: 700px;
}

.hero-eyebrow {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--bamboo);
  margin-bottom: 1.5rem;
  display: flex;
  align-items: center;
  gap: 1rem;
}
.hero-eyebrow::before {
  content: '';
  display: block;
  width: 40px; height: 1px;
  background: var(--bamboo);
}

.hero h1 { margin-bottom: 1.5rem; }
.hero h1 span { color: var(--vermilion); }

.hero-sub {
  font-size: 1.1rem;
  color: #555;
  max-width: 540px;
  margin-bottom: 3rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.85rem 2rem;
  border: 1px solid var(--ink);
  background: transparent;
  color: var(--ink);
  font-family: var(--font-mono);
  font-size: 0.8rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  cursor: pointer;
  transition: all var(--transition);
  text-decoration: none;
}
.btn:hover {
  background: var(--ink);
  color: var(--washi);
}
.btn-primary {
  background: var(--ink);
  color: var(--washi);
}
.btn-primary:hover {
  background: var(--vermilion);
  border-color: var(--vermilion);
  color: #fff;
}

.btn-gap { display: flex; gap: 1rem; flex-wrap: wrap; }

/* ── SECTION LABELS ─────────────────────────────────────── */
.section-label {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.25em;
  text-transform: uppercase;
  color: var(--bamboo);
  margin-bottom: 0.75rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
}
.section-label::after {
  content: '';
  display: block;
  flex: 1;
  height: 1px;
  background: var(--mist);
  max-width: 60px;
}

/* ── CARDS ──────────────────────────────────────────────── */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2px;
  margin-top: 3rem;
}

.card {
  background: #fff;
  padding: 2.5rem;
  border: 1px solid var(--mist);
  position: relative;
  transition: transform var(--transition), box-shadow var(--transition);
}
.card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 40px var(--shadow);
}

.card-icon {
  font-size: 2rem;
  margin-bottom: 1rem;
  display: block;
}
.card h3 { margin-bottom: 0.75rem; color: var(--ink); }
.card p { color: #666; font-size: 0.95rem; }

.card-tag {
  display: inline-block;
  margin-top: 1.5rem;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--bamboo);
  border: 1px solid var(--bamboo);
  padding: 0.25rem 0.75rem;
}

/* ── DIVIDER ────────────────────────────────────────────── */
.divider {
  width: 60px; height: 1px;
  background: var(--vermilion);
  margin: 2rem 0;
}

/* ── ABOUT SECTION ──────────────────────────────────────── */
.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 6rem;
  align-items: center;
  margin-top: 3rem;
}

.about-visual {
  position: relative;
}
.about-portrait {
  width: auto;
  max-width: 100%;
  max-height: 500px;
  display: block;
  margin: 0 auto;
  border: 1px solid #ddd;
  object-fit: contain;
}
.about-portrait p {
  font-size: 0.8rem;
  font-family: var(--font-mono);
  letter-spacing: 0.1em;
  color: #bbb;
}

.about-badge {
  position: absolute;
  bottom: -1.5rem;
  right: -1.5rem;
  background: var(--ink);
  color: var(--washi);
  padding: 1.5rem;
  font-family: var(--font-serif);
  font-size: 0.9rem;
  text-align: center;
}
.about-badge strong {
  display: block;
  font-size: 2rem;
  line-height: 1;
  color: var(--gold);
}

/* ── PRICING TABLE ──────────────────────────────────────── */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2px;
  margin-top: 3rem;
}

.price-card {
  background: #fff;
  border: 1px solid var(--mist);
  padding: 2.5rem;
  position: relative;
}
.price-card.featured {
  background: var(--ink);
  color: var(--washi);
  border-color: var(--ink);
}
.price-card.featured h3,
.price-card.featured p { color: var(--washi); }
.price-card.featured .price-amount { color: var(--gold); }

.featured-badge {
  position: absolute;
  top: -1px; right: 2rem;
  background: var(--vermilion);
  color: #fff;
  font-family: var(--font-mono);
  font-size: 0.65rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 0.3rem 0.75rem;
}

.price-amount {
  font-family: var(--font-serif);
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--ink);
  margin: 1rem 0 0.25rem;
  line-height: 1;
}
.price-unit {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  color: #999;
  margin-bottom: 1.5rem;
}
.price-card.featured .price-unit { color: #aaa; }

.price-features {
  list-style: none;
  margin-bottom: 2rem;
}
.price-features li {
  padding: 0.5rem 0;
  border-bottom: 1px solid var(--mist);
  font-size: 0.9rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
}
.price-card.featured .price-features li { border-color: rgba(255,255,255,0.1); }
.price-features li::before { content: '▸'; color: var(--bamboo); font-size: 0.7rem; }
.price-card.featured .price-features li::before { color: var(--gold); }

/* ── CONTACT ────────────────────────────────────────────── */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  margin-top: 3rem;
}

.contact-info p { margin-bottom: 0.5rem; }
.contact-item {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 1rem 0;
  border-bottom: 1px solid var(--mist);
}
.contact-item .label {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: #999;
  min-width: 80px;
}

/* ── LEGAL PAGES ────────────────────────────────────────── */
.legal-content {
  max-width: 760px;
  margin: 0 auto;
  padding: 4rem 2rem;
}
.legal-content h1 { margin-bottom: 2rem; }
.legal-content h2 {
  font-size: 1.1rem;
  margin: 2.5rem 0 0.75rem;
  padding-top: 2.5rem;
  border-top: 1px solid var(--mist);
}
.legal-content h2:first-of-type { border-top: none; }
.legal-content ul {
  padding-left: 1.5rem;
  margin-bottom: 1rem;
}
.legal-content li { margin-bottom: 0.4rem; }

/* ── EULA NOTICE BOX ────────────────────────────────────── */
.notice-box {
  background: #fff8e1;
  border-left: 3px solid var(--gold);
  padding: 1.5rem 2rem;
  margin: 2rem 0;
  font-size: 0.95rem;
}

/* ── FOOTER ─────────────────────────────────────────────── */
footer {
  background: var(--ink);
  color: rgba(245,240,232,0.6);
  padding: 3rem 0;
  margin-top: 4rem;
}
footer .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
}
.footer-logo {
  font-family: var(--font-serif);
  color: var(--washi);
  font-size: 1.1rem;
}
.footer-links {
  display: flex;
  gap: 2rem;
  list-style: none;
}
.footer-links a {
  color: rgba(245,240,232,0.5);
  font-size: 0.8rem;
  letter-spacing: 0.05em;
}
.footer-links a:hover { color: var(--washi); }
.footer-copy {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.1em;
}

/* ── BG ALT ─────────────────────────────────────────────── */
.bg-alt { background: var(--mist); }
.bg-dark { background: var(--sumi); color: var(--washi); }
.bg-dark h2, .bg-dark h3 { color: var(--washi); }
.bg-dark .section-label { color: var(--gold); }
.bg-dark .section-label::after { background: rgba(255,255,255,0.1); }

/* ── SCROLL ANIMATION ───────────────────────────────────── */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ── RESPONSIVE ─────────────────────────────────────────── */
@media (max-width: 768px) {
  .nav-links { display: none; flex-direction: column; }
  .nav-links.open {
    display: flex;
    position: fixed;
    top: 64px; left: 0; right: 0;
    background: var(--washi);
    padding: 2rem;
    border-bottom: 1px solid var(--mist);
  }
  .nav-toggle { display: flex; }
  .about-grid, .contact-grid { grid-template-columns: 1fr; }
  .about-badge { right: 0; }
  section { padding: 4rem 0; }
  .hero { min-height: 80vh; }
}

/* cache-bust 1774987835 */