:root {
  --bg: #f3faf8;
  --surface: #ffffff;
  --surface-2: #eaf6f2;
  --border: #d9ede6;
  --text: #1e2b28;
  --text-muted: #647b75;
  --accent: #12b3a0; /* fresh teal */
  --accent-dark: #0d8f80;
  --accent-2: #00c896; /* diary / CTA green */
  --accent-btc: #f7931a; /* Bitcoin orange, used sparingly */
  --shadow: 0 2px 10px rgba(18, 179, 160, 0.08);
  --max-width: 860px;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Hiragino Kaku Gothic ProN", "Yu Gothic", "Segoe UI", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.8;
  word-break: keep-all;
  overflow-wrap: break-word;
}

h1, h2, h3 {
  line-height: 1.5;
}

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

a:hover {
  text-decoration: underline;
}

header.site-header {
  border-bottom: 1px solid var(--border);
  background: var(--surface);
  box-shadow: var(--shadow);
}

.site-header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 24px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.site-title {
  font-size: 22px;
  font-weight: 700;
  color: var(--text);
  display: flex;
  align-items: center;
  gap: 8px;
}

.site-title .coin {
  color: var(--accent-btc);
}

nav.site-nav a {
  margin-left: 6px;
  padding: 8px 14px;
  border-radius: 999px;
  color: var(--text);
  font-size: 14px;
  font-weight: 600;
}

nav.site-nav a:hover {
  color: var(--accent-dark);
  background: var(--surface-2);
  text-decoration: none;
}

nav.site-nav a.nav-cta {
  margin-left: 12px;
  color: #06140f;
  background: var(--accent-2);
  box-shadow: 0 2px 8px rgba(0, 200, 150, 0.35);
}

@media (max-width: 640px) {
  .site-header-inner {
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
    padding: 16px 20px;
  }

  .site-nav {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    width: 100%;
  }

  nav.site-nav a {
    margin-left: 0;
    padding: 6px 12px;
    font-size: 13px;
    white-space: nowrap;
  }

  nav.site-nav a.nav-cta {
    margin-left: 0;
  }
}

nav.site-nav a.nav-cta:hover {
  color: #06140f;
  background: #02e0ab;
}

main {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 40px 20px;
}

.hero {
  padding: 40px 0 30px;
  border-bottom: 1px solid var(--border);
  margin-bottom: 30px;
}

.hero h1 {
  font-size: 30px;
  margin: 0 0 12px;
  text-wrap: balance;
}

.hero p {
  color: var(--text-muted);
  margin: 0;
  font-size: 15px;
}

.post-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.post-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 22px 24px;
  box-shadow: var(--shadow);
  transition: border-color 0.15s ease, transform 0.15s ease, box-shadow 0.15s ease;
}

.post-card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(18, 179, 160, 0.14);
}

.post-card .date {
  font-size: 13px;
  color: var(--text-muted);
}

.post-card h2 {
  margin: 6px 0 8px;
  font-size: 19px;
}

.post-card h2 a {
  color: var(--text);
}

.post-card h2 a:hover {
  color: var(--accent);
  text-decoration: none;
}

.post-card .excerpt {
  color: var(--text-muted);
  font-size: 14px;
  margin: 0;
}

.tag {
  display: inline-block;
  font-size: 12px;
  color: var(--accent-dark);
  background: rgba(18, 179, 160, 0.1);
  border: 1px solid rgba(18, 179, 160, 0.28);
  border-radius: 999px;
  padding: 2px 10px;
  margin-top: 10px;
}

article.post {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 32px;
  box-shadow: var(--shadow);
}

article.post .date {
  font-size: 13px;
  color: var(--text-muted);
}

article.post h1 {
  font-size: 28px;
  margin: 8px 0 24px;
  text-wrap: balance;
}

article.post h2 {
  font-size: 20px;
  margin-top: 32px;
  color: var(--accent);
}

article.post p {
  font-size: 15px;
  color: var(--text);
}

.disclaimer {
  margin-top: 32px;
  padding: 16px 18px;
  border-left: 3px solid var(--accent);
  background: var(--surface-2);
  font-size: 13px;
  color: var(--text-muted);
  border-radius: 4px;
}

.back-link {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  margin-bottom: 20px;
  padding: 8px 16px;
  font-size: 14px;
  font-weight: 600;
  color: var(--accent-dark);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 999px;
  box-shadow: var(--shadow);
}

.back-link:hover {
  border-color: var(--accent);
  background: var(--surface-2);
  text-decoration: none;
}

.tag.diary {
  color: var(--accent-2);
  background: rgba(0, 200, 150, 0.12);
  border-color: rgba(0, 200, 150, 0.3);
}

.pr-badge {
  display: inline-block;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.05em;
  color: #14110a;
  background: #ffd166;
  padding: 3px 8px;
  border-radius: 4px;
  margin-left: 8px;
  vertical-align: middle;
}

.ad-note {
  font-size: 12px;
  color: var(--text-muted);
  margin: 4px 0 0;
}

.stat-table {
  width: 100%;
  border-collapse: collapse;
  margin: 22px 0;
  font-size: 14px;
}

.stat-table td {
  padding: 10px 4px;
  border-bottom: 1px solid var(--border);
}

.stat-table td:first-child {
  color: var(--text-muted);
}

.stat-table td:last-child {
  text-align: right;
  font-weight: 600;
}

.info-box {
  margin: 22px 0;
  padding: 18px 20px;
  background: var(--surface-2);
  border-left: 3px solid var(--accent);
  border-radius: 6px;
  font-size: 14px;
}

.info-box h4 {
  margin: 0 0 8px;
  font-size: 14px;
  color: var(--accent-dark);
}

.info-box p {
  margin: 0 0 8px;
  font-size: 14px;
}

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

.info-box .source {
  font-size: 12px;
  color: var(--text-muted);
}

.chart-card {
  margin: 22px 0;
  padding: 20px 22px 16px;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 10px;
}

.chart-title {
  font-size: 13px;
  font-weight: 600;
  color: var(--text-muted);
  margin-bottom: 8px;
}

.chart-svg {
  width: 100%;
  height: auto;
  display: block;
}

.chart-caption {
  margin-top: 8px;
  font-size: 12px;
  color: var(--text-muted);
}

.screenshot-card {
  margin: 22px 0;
  padding: 16px;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 10px;
  text-align: center;
}

.screenshot-card img {
  max-width: 280px;
  width: 100%;
  border-radius: 12px;
  box-shadow: 0 4px 14px rgba(18, 179, 160, 0.18);
}

.screenshot-card .chart-caption {
  text-align: center;
}

.screenshot-row {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 16px;
}

.screenshot-row .screenshot-card {
  flex: 1 1 240px;
}

.cta-box {
  margin-top: 36px;
  padding: 26px 28px;
  border: 1px solid rgba(0, 200, 150, 0.35);
  background: linear-gradient(180deg, rgba(0, 200, 150, 0.08), rgba(0, 200, 150, 0.02));
  border-radius: 12px;
}

.cta-box h3 {
  margin: 0 0 10px;
  font-size: 17px;
  color: var(--text);
}

.cta-box p {
  margin: 0 0 4px;
}

.cta-btn {
  display: inline-block;
  margin-top: 14px;
  padding: 14px 26px;
  background: var(--accent-2);
  color: #06140f;
  font-weight: 700;
  font-size: 15px;
  border-radius: 8px;
}

.cta-btn:hover {
  background: #02e0ab;
  text-decoration: none;
}

.cta-note {
  font-size: 12px;
  color: var(--text-muted);
  margin-top: 16px;
  line-height: 1.7;
}

footer.site-footer {
  border-top: 1px solid var(--border);
  margin-top: 60px;
  padding: 24px 20px;
  text-align: center;
  color: var(--text-muted);
  font-size: 13px;
}

@media (max-width: 640px) {
  main {
    padding: 28px 16px;
  }

  .hero {
    padding: 24px 0 20px;
  }

  .hero h1 {
    font-size: 24px;
    line-height: 1.5;
  }

  .hero p {
    font-size: 14px;
  }

  .post-card {
    padding: 18px;
  }

  .post-card h2 {
    font-size: 17px;
  }

  .post-card .excerpt {
    font-size: 13.5px;
  }

  article.post {
    padding: 22px 18px;
  }

  article.post h1 {
    font-size: 22px;
    margin: 4px 0 20px;
  }

  article.post h2 {
    font-size: 18px;
    margin-top: 28px;
  }

  article.post p {
    font-size: 16px;
    line-height: 1.9;
  }

  .info-box,
  .info-box p {
    font-size: 14px;
  }

  .stat-table {
    font-size: 13.5px;
  }

  .chart-card {
    padding: 16px 16px 12px;
  }

  .chart-title {
    font-size: 13px;
  }

  .chart-caption {
    font-size: 12.5px;
  }

  .cta-box {
    padding: 20px;
  }

  .cta-box h3 {
    font-size: 16px;
  }

  .cta-btn {
    display: block;
    text-align: center;
  }
}