:root { --primary: #06BBCC; --light: #F0FBFC; --dark: #181d38; }
html, body { overflow-x: hidden; }
body { font-family: 'Noto Sans JP', sans-serif; color: #333; }
h1,h2,h3,h4,h5,h6,.btn { font-family: 'Noto Sans JP', sans-serif; }
.btn { font-weight: 700; transition: .3s; }
.btn-primary { background-color: var(--primary); border-color: var(--primary); color: #fff; }
.btn-primary:hover { background-color: #05a8b8; border-color: #05a8b8; color: #fff; }
.btn-outline-primary { border-color: var(--primary); color: var(--primary); }
.btn-outline-primary:hover { background-color: var(--primary); color: #fff; }
.text-primary { color: var(--primary) !important; }
.bg-light-primary { background: var(--light); }
.section-py { padding: 50px 0; }
a { color: var(--primary); text-decoration: none; }
a:hover { color: #05a8b8; }

/* Section label */
.section-label {
  display: inline-block; font-size: 11px; font-weight: 700;
  letter-spacing: .15em; text-transform: uppercase;
  color: var(--primary); margin-bottom: 10px;
}

/* Back link */
.lesson-back-link { background: #f8fafb; border-bottom: 1px solid #e0f5f7; padding: 10px 0; }
.lesson-back-link a { font-size: .85rem; color: #888; display: inline-flex; align-items: center; gap: 6px; }
.lesson-back-link a:hover { color: var(--primary); }
@media (max-width: 767px) { .lesson-back-link { padding: 10px 24px; } }

/* Hero */
.lesson-hero {
  background: linear-gradient(135deg, rgba(24,29,56,.55) 0%, rgba(6,50,80,.50) 100%),
    url('../img/bg_focus.jpg') center/cover no-repeat;
  padding: 100px 0 80px; color: #fff;
}
.lesson-hero h1 { font-size: 2.4rem; font-weight: 900; line-height: 1.3; margin-bottom: 16px; }
.lesson-hero .hero-code { font-size: 1rem; opacity: .8; margin-bottom: 8px; font-weight: 700; letter-spacing: .1em; }
.lesson-hero p { font-size: 1rem; opacity: .9; max-width: 600px; line-height: 1.8; }
@media (max-width: 767px) {
  .lesson-hero { padding: 100px 24px 80px; }
  .lesson-hero h1 { font-size: 1.8rem; }
}

/* Skill badges */
.skill-badge {
  display: inline-flex; align-items: center; gap: 4px;
  background: rgba(255,255,255,.15); border: 1px solid rgba(255,255,255,.3);
  border-radius: 20px; padding: 4px 14px; font-size: 0.78rem; color: #fff;
  margin: 4px 4px 4px 0;
}

/* Info card */
.info-card {
  background: var(--light); border-radius: 10px; padding: 24px 28px;
}
.info-row { display: flex; align-items: flex-start; gap: 12px; margin-bottom: 12px; font-size: .9rem; }
.info-row:last-child { margin-bottom: 0; }
.info-row .bi { color: var(--primary); font-size: 1.1rem; flex-shrink: 0; margin-top: 2px; }
.info-label { font-weight: 700; color: #1a3a4c; min-width: 80px; }
.service-tag {
  display: inline-block; background: var(--primary); color: #fff;
  font-size: .72rem; font-weight: 700; padding: 3px 10px;
  border-radius: 20px; margin: 4px 4px 0 0; text-decoration: none;
}
.service-tag:hover { background: #05a8b8; color: #fff; }

/* Content box */
.content-box {
  background: #fff; border: 1px solid #e0f5f7; border-radius: 12px;
  padding: 32px; margin-bottom: 24px;
}
.content-box h5 { font-weight: 800; color: #1a3a4c; margin-bottom: 16px; font-size: 1.05rem; }

/* Flow steps */
.flow-step { position: relative; padding-left: 56px; padding-bottom: 28px; margin-bottom: 0; }
.flow-step:last-child { padding-bottom: 0; }
.flow-step::before {
  content: ""; position: absolute; left: 17px; top: 36px;
  width: 2px; height: calc(100% - 36px); background: #d0eef1;
}
.flow-step:last-child::before { display: none; }
.flow-step-num {
  position: absolute; left: 0; top: 0;
  width: 36px; height: 36px; border-radius: 50%;
  background: var(--primary); color: #fff;
  font-weight: 900; font-size: .85rem;
  display: flex; align-items: center; justify-content: center;
  box-shadow: 0 2px 8px rgba(6,187,204,.3);
}
.flow-step-body { padding-top: 4px; }
.flow-step-title { font-weight: 700; font-size: .95rem; color: #1a3a4c; margin-bottom: 2px; }
.flow-step-time { font-size: .78rem; color: var(--primary); font-weight: 600; }
.flow-step-desc { font-size: .85rem; color: #666; line-height: 1.7; margin-top: 4px; }

/* Curriculum table */
.lesson-table { width: 100%; border-collapse: collapse; font-size: .88rem; }
.lesson-table thead tr { background: var(--primary); color: #fff; }
.lesson-table th { padding: 12px 16px; font-weight: 700; }
.lesson-table td { padding: 12px 16px; border-bottom: 1px solid #e0f5f7; color: #444; }
.lesson-table tbody tr:nth-child(even) { background: var(--light); }
.lesson-table tbody tr:hover { background: #e0f7fa; }

/* Related lessons */
.related-card {
  background: #fff; border: 1px solid #e0f5f7; border-radius: 10px;
  overflow: hidden; transition: .3s; text-decoration: none; display: block;
}
.related-card:hover { box-shadow: 0 6px 20px rgba(6,187,204,.18); transform: translateY(-3px); border-color: var(--primary); }
.related-card img { width: 100%; aspect-ratio: 4/3; object-fit: contain; padding: 16px; background: var(--light); }
.related-card-body { padding: 14px; }
.related-card-code { font-size: .72rem; font-weight: 700; color: var(--primary); letter-spacing: .1em; }
.related-card-title { font-size: .88rem; font-weight: 700; color: #1a3a4c; margin-top: 4px; }

/* CTA */
.lesson-cta {
  background: linear-gradient(135deg, var(--dark) 0%, #0a4060 100%);
  padding: 80px 0; text-align: center; color: #fff;
}
.lesson-cta h2 { font-size: 1.8rem; font-weight: 900; margin-bottom: 16px; }
.lesson-cta p { font-size: 1rem; opacity: .85; margin-bottom: 32px; }

/* Index page */
.lesson-index-card {
  background: #fff; border: 1.5px solid #e0f5f7; border-radius: 10px;
  overflow: hidden; height: 100%; transition: .3s; text-decoration: none; display: block;
}
.lesson-index-card:hover { box-shadow: 0 6px 18px rgba(6,187,204,.18); transform: translateY(-3px); border-color: var(--primary); }
.lesson-index-card img { width: 100%; aspect-ratio: 4/3; object-fit: contain; padding: 12px; background: var(--light); }
.lesson-index-card-body { padding: 10px 12px 12px; }
.lesson-index-card-code { font-size: .68rem; font-weight: 700; color: var(--primary); letter-spacing: .12em; text-transform: uppercase; }
.lesson-index-card-title { font-size: .82rem; font-weight: 700; color: #1a3a4c; margin: 4px 0 6px; line-height: 1.4; }
.lesson-index-card-desc { font-size: .75rem; color: #666; line-height: 1.7; }

/* Alert box */
.alert-primary-custom {
  background: var(--light); border: 1.5px solid var(--primary);
  border-radius: 10px; padding: 20px 24px;
  font-size: .9rem; line-height: 1.8; color: #444;
}
.alert-primary-custom .alert-title { font-weight: 800; color: var(--primary); margin-bottom: 8px; font-size: 1rem; }