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

body {
  margin: 0;
  padding: 0;
  font-family: system-ui, -apple-system, "Hiragino Kaku Gothic ProN", "Noto Sans JP", sans-serif;
  font-size: 16px;
  line-height: 1.7;
  color: #1A1A1A;
  background-color: #FFFFFF;
}

a {
  color: #0066CC;
  text-decoration: underline;
}

a:hover,
a:focus {
  text-decoration: none;
  outline: 2px solid #0066CC;
  outline-offset: 2px;
}

/* Header */
.site-header {
  border-bottom: 1px solid #DDDDDD;
  padding: 16px 24px;
}

.site-header .site-name {
  font-size: 1.25rem;
  font-weight: bold;
  margin: 0;
}

.site-header .site-name a {
  color: #1A1A1A;
  text-decoration: none;
}

.site-header .site-name a:hover,
.site-header .site-name a:focus {
  text-decoration: underline;
  outline: 2px solid #0066CC;
  outline-offset: 2px;
}

/* Main */
main {
  max-width: 720px;
  margin: 0 auto;
  padding: 40px 24px;
}

section {
  margin-bottom: 48px;
}

section:last-child {
  margin-bottom: 0;
}

h1, h2 {
  line-height: 1.4;
}

h1 {
  font-size: 1.5rem;
  margin-top: 0;
  margin-bottom: 16px;
}

h2 {
  font-size: 1.25rem;
  margin-top: 0;
  margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid #DDDDDD;
}

h3 {
  font-size: 1.1rem;
  margin-top: 24px;
  margin-bottom: 8px;
}

p {
  margin-top: 0;
  margin-bottom: 12px;
}

/* Footer */
.site-footer {
  background-color: #F5F5F5;
  border-top: 1px solid #DDDDDD;
  padding: 24px;
  text-align: center;
  font-size: 0.875rem;
  color: #555555;
}

.site-footer p {
  margin: 4px 0;
}

.site-footer a {
  color: #0066CC;
}

/* Contact mail */
#contact-mail a {
  color: #0066CC;
  text-decoration: underline;
}

/* Privacy policy */
.privacy-content h3 {
  font-size: 1rem;
}

.privacy-content ul {
  padding-left: 1.5em;
  margin-bottom: 12px;
}

.privacy-effective {
  color: #555555;
  font-size: 0.9rem;
  margin-top: 32px;
}

/* Responsive */
@media (max-width: 600px) {
  main {
    padding: 24px 16px;
  }

  .site-header {
    padding: 12px 16px;
  }

  .site-footer {
    padding: 16px;
  }
}