/* ========================================
   Ca2CO6 — Clean, Sincere Design
   ======================================== */

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

:root {
  --bg: #fafaf8;
  --bg-alt: #f2f1ed;
  --bg-card: #ffffff;
  --text: #1a1a1a;
  --text-secondary: #555;
  --text-muted: #888;
  --accent: #2a5a3a;
  --accent-light: #e8f0eb;
  --border: #e0dfdb;
  --border-light: #eeedea;
  --font-sans: 'Noto Sans JP', 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-serif: 'Noto Serif JP', 'Georgia', serif;
  --max-width: 680px;
  --ease: cubic-bezier(0.25, 0.1, 0.25, 1);
}

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
}

body {
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--text);
  line-height: 1.85;
  font-size: 15px;
}

a {
  color: var(--accent);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

strong {
  font-weight: 600;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* --- Navbar --- */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: var(--bg-card);
  border-bottom: 1px solid var(--border);
  box-shadow: 0 10px 28px rgba(26, 26, 26, 0.08);
}

.nav-inner {
  max-width: 900px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 56px;
}

.nav-logo {
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: 1rem;
  color: var(--text);
  display: flex;
  align-items: baseline;
  gap: 8px;
}

.nav-logo:hover {
  text-decoration: none;
}

.nav-logo-sub {
  font-family: var(--font-sans);
  font-size: 0.75rem;
  font-weight: 400;
  color: var(--text-muted);
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 4px;
  list-style: none;
}

.nav-link {
  padding: 6px 12px;
  font-size: 0.8rem;
  color: var(--text);
  font-weight: 500;
  border-radius: 6px;
  transition: background 0.2s, color 0.2s;
}

.nav-link:hover {
  background: var(--bg-alt);
  color: var(--text);
  text-decoration: none;
}

.nav-cta {
  color: var(--accent) !important;
  font-weight: 500;
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  flex-direction: column;
  gap: 5px;
}

.nav-toggle span {
  display: block;
  width: 18px;
  height: 1.5px;
  background: var(--text);
  border-radius: 1px;
  transition: all 0.3s var(--ease);
}

/* --- Hero --- */
.hero {
  padding: 140px 0 80px;
}

.hero-greeting {
  font-family: var(--font-serif);
  font-size: 1rem;
  color: var(--text-muted);
  margin-bottom: 16px;
}

.hero-title {
  font-family: var(--font-serif);
  font-size: clamp(1.5rem, 4vw, 2rem);
  font-weight: 600;
  line-height: 1.6;
  letter-spacing: 0.01em;
  margin-bottom: 24px;
  color: var(--text);
}

.hero-lead {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.9;
  margin-bottom: 32px;
}

.hero-cta {
  display: inline-block;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--accent);
  padding: 10px 0;
  border-bottom: 1px solid var(--accent);
  transition: opacity 0.2s;
}

.hero-cta:hover {
  opacity: 0.7;
  text-decoration: none;
}

/* --- Sections --- */
.section {
  padding: 72px 0;
}

.section-alt {
  background: var(--bg-alt);
}

.section-title {
  font-family: var(--font-serif);
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 28px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border);
}

.section-lead {
  color: var(--text-secondary);
  font-size: 0.95rem;
  margin-bottom: 24px;
}

.section-note {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-top: 24px;
  line-height: 1.8;
}

/* --- Prose --- */
.prose p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  margin-bottom: 16px;
  line-height: 1.9;
}

.prose p:last-child {
  margin-bottom: 0;
}

/* --- Support Grid --- */
.support-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-top: 32px;
}

.support-item {
  padding: 20px;
  background: var(--bg-alt);
  border-radius: 8px;
}

.support-item h3 {
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 6px;
}

.support-item-title-link {
  color: var(--accent);
}

.support-item-title-link:hover {
  text-decoration: none;
  opacity: 0.75;
}

.support-item p {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* --- Scores Table --- */
.scores-table {
  overflow-x: auto;
  margin-bottom: 8px;
}

.scores-table table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9rem;
}

.scores-table th {
  text-align: left;
  font-weight: 500;
  font-size: 0.8rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  padding: 10px 12px;
  border-bottom: 2px solid var(--border);
}

.scores-table td {
  padding: 10px 12px;
  border-bottom: 1px solid var(--border-light);
  vertical-align: middle;
}

.scores-table tr:last-child td {
  border-bottom: none;
}

.row-highlight td {
  background: var(--accent-light);
}

.note {
  font-size: 0.75rem;
  color: var(--accent);
  margin-left: 6px;
  font-weight: 500;
}

/* --- SAT inline --- */
.sat-inline {
  margin-top: 32px;
  padding: 20px;
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: 8px;
}

.sat-inline h3 {
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 4px;
}

.sat-inline p {
  font-size: 0.9rem;
  color: var(--text-secondary);
}

/* --- Achievements --- */
.achievements-columns {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
}

.achievement-col h3 {
  font-size: 0.95rem;
  font-weight: 600;
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 8px;  
}

.badge {
  font-size: 0.7rem;
  font-weight: 500;
  color: var(--accent);
  background: var(--accent-light);
  padding: 2px 8px;
  border-radius: 4px;
}

.achievement-col ul {
  list-style: none;
}

.achievement-col li {
  font-size: 0.9rem;
  padding: 8px 0;
  border-bottom: 1px solid var(--border-light);
  line-height: 1.6;
}

.achievement-col li:last-child {
  border-bottom: none;
}

.detail {
  display: block;
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* --- Pricing --- */
.pricing-box {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: 8px;
  padding: 28px;
}

.pricing-main {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 12px;
}

.pricing-label {
  font-size: 0.9rem;
  font-weight: 500;
}

.pricing-amount {
  font-family: var(--font-serif);
  font-size: 1.3rem;
  font-weight: 600;
}

.pricing-unit {
  font-size: 0.85rem;
  font-weight: 400;
  color: var(--text-muted);
}

.pricing-note {
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* --- FAQ --- */
.faq-list {
  display: flex;
  flex-direction: column;
  gap: 0;
}

.faq-item {
  border-bottom: 1px solid var(--border-light);
}

.faq-item:first-child {
  border-top: 1px solid var(--border-light);
}

.faq-item summary {
  padding: 16px 0;
  font-size: 0.95rem;
  font-weight: 500;
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: color 0.2s;
}

.faq-item summary::-webkit-details-marker {
  display: none;
}

.faq-item summary::after {
  content: '+';
  font-size: 1.1rem;
  color: var(--text-muted);
  flex-shrink: 0;
  margin-left: 16px;
  transition: transform 0.2s;
}

.faq-item[open] summary::after {
  content: '−';
}

.faq-item summary:hover {
  color: var(--accent);
}

.faq-item p {
  padding: 0 0 16px;
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.8;
}

/* --- Contact --- */
.contact-box {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: 8px;
  padding: 28px;
}

.contact-box > p {
  font-size: 0.95rem;
  color: var(--text-secondary);
  margin-bottom: 16px;
}

.contact-email {
  display: inline-block;
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--accent);
  padding: 12px 24px;
  background: var(--accent-light);
  border-radius: 8px;
  margin-bottom: 20px;
  transition: background 0.2s;
}

.contact-email:hover {
  background: #d6e6db;
  text-decoration: none;
}

.contact-checklist p {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 8px;
}

.contact-checklist ul {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 4px 16px;
}

.contact-checklist li {
  font-size: 0.85rem;
  color: var(--text-muted);
}

.contact-checklist li::before {
  content: '· ';
}

/* --- Method Steps --- */
.method-steps {
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin-top: 24px;
}

.method-step {
  display: flex;
  gap: 16px;
  align-items: flex-start;
  padding: 16px;
  background: var(--bg-alt);
  border-radius: 8px;
}

.section-alt .method-step {
  background: var(--bg-card);
}

.step-number {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  min-width: 32px;
  background: var(--accent);
  color: #fff;
  border-radius: 50%;
  font-size: 0.85rem;
  font-weight: 600;
  font-family: var(--font-sans);
}

.method-step h3 {
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 4px;
}

.method-step p {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* --- Guide List --- */
.guide-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.guide-item {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 20px;
  background: var(--bg-alt);
  border: 1px solid var(--border-light);
  border-radius: 8px;
  transition: border-color 0.2s, background 0.2s;
}

.guide-item:hover {
  border-color: var(--border);
  background: var(--bg-card);
  text-decoration: none;
}

.guide-subject {
  font-weight: 600;
  font-size: 0.95rem;
  min-width: 120px;
  flex-shrink: 0;
}

.guide-desc {
  font-size: 0.85rem;
  color: var(--text-secondary);
  flex: 1;
}

.guide-arrow {
  color: var(--text-muted);
  font-size: 1rem;
  flex-shrink: 0;
}

/* --- Sample Materials --- */
.sample-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.sample-item {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 16px 20px;
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: 8px;
  transition: border-color 0.2s;
}

.sample-item:hover {
  border-color: var(--border);
  text-decoration: none;
}

.sample-icon {
  font-size: 0.7rem;
  font-weight: 600;
  color: var(--text-muted);
  background: var(--bg-alt);
  padding: 4px 8px;
  border-radius: 4px;
  letter-spacing: 0.03em;
}

.sample-name {
  font-weight: 500;
  font-size: 0.9rem;
}

.sample-meta {
  font-size: 0.75rem;
  color: var(--text-muted);
}

.sample-item .guide-arrow {
  margin-left: auto;
}

/* --- Blog Article --- */
.article {
  padding: 120px 0 72px;
}

.article-header {
  margin-bottom: 40px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--border);
}

.article-tag {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--accent);
  background: var(--accent-light);
  padding: 3px 10px;
  border-radius: 4px;
  margin-bottom: 12px;
}

.article-title {
  font-family: var(--font-serif);
  font-size: clamp(1.4rem, 3.5vw, 1.8rem);
  font-weight: 600;
  line-height: 1.5;
  margin-bottom: 8px;
}

.article-meta {
  color: var(--text-muted);
  font-size: 0.85rem;
}

.article-body h2 {
  font-family: var(--font-serif);
  font-size: 1.15rem;
  font-weight: 600;
  margin-top: 40px;
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border-light);
}

.article-body h3 {
  font-size: 0.95rem;
  font-weight: 600;
  margin-top: 24px;
  margin-bottom: 8px;
}

.article-body p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.9;
  margin-bottom: 16px;
}

.article-body ul,
.article-body ol {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.9;
  margin-bottom: 16px;
  padding-left: 24px;
}

.article-body li {
  margin-bottom: 6px;
}

.article-cta {
  margin-top: 48px;
  padding: 28px;
  background: var(--bg-alt);
  border-radius: 8px;
  text-align: center;
}

.article-cta p {
  margin-bottom: 12px;
}

.article-author {
  margin-top: 40px;
  padding: 20px 22px;
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: 8px;
}

.article-author-label {
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--accent);
  letter-spacing: 0.04em;
  margin-bottom: 6px;
}

.article-author p:last-child {
  margin-bottom: 0;
}

.article-related {
  margin-top: 40px;
}

.article-related .guide-list {
  margin-top: 16px;
}

/* --- Nav Back Link --- */
.nav-back {
  font-size: 0.85rem;
  color: var(--text-muted) !important;
}

.nav-back:hover {
  color: var(--text) !important;
}

/* --- Footer --- */
.footer {
  padding: 32px 0;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.8rem;
}

/* ========================================
   Responsive
   ======================================== */
@media (max-width: 768px) {
  .nav-toggle {
    display: flex;
  }

  .nav-menu {
    position: fixed;
    top: 56px;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(250, 250, 248, 0.98);
    backdrop-filter: blur(12px);
    flex-direction: column;
    padding: 32px 24px;
    gap: 4px;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s var(--ease);
  }

  .nav-menu.active {
    opacity: 1;
    visibility: visible;
  }

  .nav-link {
    font-size: 1rem;
    padding: 12px 0;
  }

  .nav-toggle.active span:first-child {
    transform: rotate(45deg) translate(2px, 2px);
  }

  .nav-toggle.active span:last-child {
    transform: rotate(-45deg) translate(2px, -2px);
  }

  .hero {
    padding: 110px 0 60px;
  }

  .support-grid {
    grid-template-columns: 1fr;
  }

  .achievements-columns {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .pricing-main {
    flex-direction: column;
  }
}

/* --- Subtle entrance animation --- */
.animate-in {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity 0.5s var(--ease), transform 0.5s var(--ease);
}

.animate-in.visible {
  opacity: 1;
  transform: translateY(0);
}