/* ============================================
   Study Again 40 — Global Stylesheet
   Design: Fresh Green × Amber Gold
   ============================================ */

:root {
  --green:        #166534;
  --green-mid:    #15803D;
  --green-light:  #16A34A;
  --green-pale:   #DCFCE7;
  --green-ultra:  #F0FDF4;
  --amber:        #F59E0B;
  --amber-dark:   #D97706;
  --amber-pale:   #FEF3C7;
  --bg:           #FAFFF7;
  --bg-white:     #FFFFFF;
  --text:         #1C1C1E;
  --text-mid:     #374151;
  --text-muted:   #6B7280;
  --border:       #D1FAE5;
  --border-mid:   #A7F3D0;
  --shadow-sm:    0 1px 3px rgba(22,101,52,0.08);
  --shadow-md:    0 4px 16px rgba(22,101,52,0.10);
  --shadow-lg:    0 8px 32px rgba(22,101,52,0.12);
  --radius-sm:    6px;
  --radius-md:    12px;
  --radius-lg:    20px;
  --radius-xl:    28px;
}

/* ---- Reset ---- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: 'Noto Sans JP', 'Hiragino Kaku Gothic ProN', sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }

/* ---- Layout ---- */
.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ============================================
   HEADER
   ============================================ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(250,255,247,0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}
.site-logo {
  display: flex;
  align-items: center;
  gap: 10px;
}
.logo-icon {
  font-size: 26px;
  line-height: 1;
}
.logo-text {
  display: flex;
  flex-direction: column;
}
.logo-main {
  font-family: 'Inter', sans-serif;
  font-size: 18px;
  font-weight: 800;
  color: var(--green);
  letter-spacing: -0.3px;
  line-height: 1.1;
}
.logo-sub {
  font-size: 10px;
  color: var(--text-muted);
  letter-spacing: 0.5px;
  line-height: 1;
}
.site-nav {
  display: flex;
  align-items: center;
  gap: 28px;
}
.site-nav a {
  font-size: 14px;
  font-weight: 500;
  color: var(--text-mid);
  transition: color 0.2s;
}
.site-nav a:hover { color: var(--green); }

/* ============================================
   HERO
   ============================================ */
.hero {
  padding: 72px 0 80px;
  background: linear-gradient(135deg, #F0FDF4 0%, #FAFFF7 50%, #FEF9EE 100%);
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: '';
  position: absolute;
  top: -80px; right: -80px;
  width: 400px; height: 400px;
  background: radial-gradient(circle, rgba(22,160,72,0.08) 0%, transparent 70%);
  pointer-events: none;
}
.hero::after {
  content: '';
  position: absolute;
  bottom: -60px; left: -60px;
  width: 300px; height: 300px;
  background: radial-gradient(circle, rgba(245,158,11,0.07) 0%, transparent 70%);
  pointer-events: none;
}
.hero .container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
}
.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 14px;
  background: var(--green-pale);
  color: var(--green);
  border-radius: 99px;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.8px;
  margin-bottom: 20px;
  border: 1px solid var(--border-mid);
}
.hero-title {
  font-family: 'Noto Serif JP', 'Noto Sans JP', serif;
  font-size: 48px;
  font-weight: 700;
  line-height: 1.3;
  color: var(--text);
  margin-bottom: 20px;
  letter-spacing: -0.5px;
}
.hero-accent {
  color: var(--green);
  position: relative;
}
.hero-accent::after {
  content: '';
  position: absolute;
  bottom: 2px; left: 0; right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--amber), var(--amber-dark));
  border-radius: 2px;
  opacity: 0.7;
}
.hero-lead {
  font-size: 15px;
  color: var(--text-mid);
  line-height: 1.8;
  margin-bottom: 32px;
}
.hero-cta {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  padding: 13px 28px;
  border-radius: 99px;
  font-size: 14px;
  font-weight: 700;
  cursor: pointer;
  transition: all 0.2s;
  border: 2px solid transparent;
}
.btn-primary {
  background: var(--green);
  color: #fff;
  box-shadow: 0 4px 14px rgba(22,101,52,0.25);
}
.btn-primary:hover {
  background: var(--green-mid);
  transform: translateY(-1px);
  box-shadow: 0 6px 20px rgba(22,101,52,0.3);
}
.btn-outline {
  background: transparent;
  color: var(--green);
  border-color: var(--green);
}
.btn-outline:hover {
  background: var(--green-pale);
}
.btn-green-outline {
  background: transparent;
  color: var(--green);
  border: 2px solid var(--border-mid);
  font-size: 13px;
  padding: 10px 22px;
}
.btn-green-outline:hover {
  background: var(--green-pale);
  border-color: var(--green);
}

/* Hero Visual */
.hero-stats {
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.stat-card {
  background: var(--bg-white);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 18px 24px;
  display: flex;
  align-items: center;
  gap: 16px;
  box-shadow: var(--shadow-sm);
  transition: transform 0.2s, box-shadow 0.2s;
}
.stat-card:hover {
  transform: translateX(4px);
  box-shadow: var(--shadow-md);
}
.stat-num {
  font-family: 'Inter', sans-serif;
  font-size: 28px;
  font-weight: 800;
  color: var(--green);
  min-width: 60px;
  line-height: 1;
}
.stat-label {
  font-size: 13px;
  color: var(--text-mid);
  font-weight: 500;
}

/* ============================================
   ABOUT SECTION (3 points)
   ============================================ */
.about-section {
  padding: 64px 0;
  background: var(--bg-white);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}
.about-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}
.about-point {
  text-align: center;
  padding: 8px;
}
.about-icon {
  font-size: 36px;
  margin-bottom: 14px;
  line-height: 1;
}
.about-point h3 {
  font-size: 16px;
  font-weight: 700;
  color: var(--green);
  margin-bottom: 8px;
}
.about-point p {
  font-size: 13px;
  color: var(--text-muted);
  line-height: 1.7;
}

/* ============================================
   SECTION COMMONS
   ============================================ */
.section-header {
  text-align: center;
  margin-bottom: 40px;
}
.section-title {
  font-family: 'Inter', 'Noto Sans JP', sans-serif;
  font-size: 28px;
  font-weight: 800;
  color: var(--text);
  margin-bottom: 8px;
  letter-spacing: -0.3px;
}
.section-title::after {
  content: '';
  display: block;
  width: 40px;
  height: 3px;
  background: linear-gradient(90deg, var(--green), var(--amber));
  border-radius: 2px;
  margin: 10px auto 0;
}
.section-sub {
  font-size: 14px;
  color: var(--text-muted);
  margin-top: 10px;
}

/* ============================================
   CATEGORIES
   ============================================ */
.categories-section {
  padding: 72px 0;
}
.category-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}
.category-card {
  display: block;
  background: var(--bg-white);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 28px 20px 24px;
  text-align: center;
  transition: all 0.25s;
  position: relative;
  overflow: hidden;
}
.category-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 4px;
  opacity: 0;
  transition: opacity 0.25s;
}
.cat-boki::before   { background: linear-gradient(90deg, #166534, #16A34A); }
.cat-it::before     { background: linear-gradient(90deg, #0369A1, #0EA5E9); }
.cat-english::before{ background: linear-gradient(90deg, #7C3AED, #A78BFA); }
.cat-guide::before  { background: linear-gradient(90deg, #D97706, #F59E0B); }

.category-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--border-mid);
}
.category-card:hover::before { opacity: 1; }
.cat-icon {
  font-size: 40px;
  margin-bottom: 12px;
  line-height: 1;
}
.category-card h3 {
  font-size: 15px;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 8px;
}
.category-card p {
  font-size: 12px;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 14px;
}
.cat-count {
  font-size: 11px;
  color: var(--green);
  font-weight: 600;
  background: var(--green-pale);
  padding: 3px 10px;
  border-radius: 99px;
}

/* ============================================
   ARTICLES
   ============================================ */
.articles-section {
  padding: 72px 0;
  background: var(--green-ultra);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}
.article-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.article-card {
  background: var(--bg-white);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 24px 28px;
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 16px;
  align-items: start;
  transition: box-shadow 0.2s, transform 0.2s;
  position: relative;
}
.article-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateX(3px);
}
.article-badge {
  font-family: 'Inter', sans-serif;
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 1px;
  color: var(--amber-dark);
  background: var(--amber-pale);
  padding: 4px 10px;
  border-radius: 4px;
  white-space: nowrap;
  align-self: center;
  border: 1px solid #FDE68A;
}
.article-card h3 {
  font-size: 15px;
  font-weight: 700;
  color: var(--text);
  line-height: 1.5;
  margin-bottom: 6px;
}
.article-card p {
  font-size: 13px;
  color: var(--text-muted);
  line-height: 1.6;
}
.article-meta {
  display: flex;
  flex-direction: column;
  gap: 6px;
  align-self: center;
  text-align: right;
}
.article-cat {
  font-size: 11px;
  font-weight: 600;
  color: var(--green);
  background: var(--green-pale);
  padding: 3px 10px;
  border-radius: 99px;
  white-space: nowrap;
}
.article-date {
  font-size: 11px;
  color: var(--text-muted);
}

/* ============================================
   PROFILE TEASER
   ============================================ */
.profile-teaser {
  padding: 72px 0;
}
.profile-teaser-inner {
  display: flex;
  align-items: center;
  gap: 40px;
  background: var(--bg-white);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  padding: 40px 48px;
  box-shadow: var(--shadow-md);
}
.avatar-placeholder {
  width: 90px;
  height: 90px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--green), var(--green-light));
  color: #fff;
  font-family: 'Inter', sans-serif;
  font-size: 26px;
  font-weight: 800;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  box-shadow: 0 4px 16px rgba(22,101,52,0.25);
}
.profile-label {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 1.5px;
  color: var(--green);
  text-transform: uppercase;
  margin-bottom: 6px;
}
.profile-name {
  font-size: 22px;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 10px;
}
.profile-info p {
  font-size: 14px;
  color: var(--text-mid);
  line-height: 1.7;
  margin-bottom: 18px;
}

/* ============================================
   FOOTER
   ============================================ */
.site-footer {
  background: var(--green);
  color: rgba(255,255,255,0.85);
  padding: 48px 0 24px;
}
.footer-top {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  padding-bottom: 32px;
  border-bottom: 1px solid rgba(255,255,255,0.15);
  margin-bottom: 24px;
}
.footer-logo {
  font-family: 'Inter', sans-serif;
  font-size: 20px;
  font-weight: 800;
  color: #fff;
  display: block;
  margin-bottom: 6px;
}
.footer-brand p {
  font-size: 13px;
  color: rgba(255,255,255,0.6);
}
.footer-links {
  display: flex;
  gap: 24px;
  align-items: center;
}
.footer-links a {
  font-size: 13px;
  color: rgba(255,255,255,0.7);
  transition: color 0.2s;
}
.footer-links a:hover { color: #fff; }
.footer-bottom {
  text-align: center;
  font-size: 12px;
  color: rgba(255,255,255,0.4);
}

/* ============================================
   RESPONSIVE
   ============================================ */
@media (max-width: 900px) {
  .hero .container {
    grid-template-columns: 1fr;
    gap: 40px;
  }
  .hero-title { font-size: 38px; }
  .category-grid { grid-template-columns: repeat(2, 1fr); }
  .about-grid { grid-template-columns: 1fr; gap: 24px; }
  .profile-teaser-inner { flex-direction: column; text-align: center; padding: 32px 28px; }
}
@media (max-width: 600px) {
  .hero { padding: 48px 0 56px; }
  .hero-title { font-size: 32px; }
  .category-grid { grid-template-columns: 1fr 1fr; gap: 12px; }
  .article-card {
    grid-template-columns: 1fr;
    gap: 10px;
  }
  .article-meta { flex-direction: row; text-align: left; }
  .site-nav { display: none; }
  .footer-top { flex-direction: column; gap: 24px; }
  .footer-links { flex-wrap: wrap; gap: 16px; }
}