:root {
  --bp-lg: 1024px;
  --bp-md: 768px;
  --bp-sm: 480px;
}

html,
body {
  overflow-x: clip;
}

img,
svg {
  max-width: 100%;
  height: auto;
}

body.is-nav-open {
  overflow: hidden;
}

.menu-button,
.nav-toggle {
  display: none;
  position: relative;
  width: 44px;
  height: 44px;
  border: 1px solid rgba(31, 77, 58, 0.2);
  border-radius: 999px;
  background: #fff;
  align-items: center;
  justify-content: center;
  color: #1f4d3a;
  cursor: pointer;
  flex: 0 0 auto;
}

.menu-button span,
.menu-button::before,
.menu-button::after,
.nav-toggle span,
.nav-toggle::before,
.nav-toggle::after {
  content: "";
  position: absolute;
  width: 18px;
  height: 2px;
  border-radius: 999px;
  background: currentColor;
  transition: transform 0.2s ease, opacity 0.2s ease;
}

.menu-button::before,
.nav-toggle::before {
  transform: translateY(-6px);
}

.menu-button::after,
.nav-toggle::after {
  transform: translateY(6px);
}

.menu-button.is-active span,
.nav-toggle.is-active span {
  opacity: 0;
}

.menu-button.is-active::before,
.nav-toggle.is-active::before {
  transform: rotate(45deg);
}

.menu-button.is-active::after,
.nav-toggle.is-active::after {
  transform: rotate(-45deg);
}

@media (max-width: 1024px) {
  .menu-button,
  .nav-toggle {
    display: inline-flex;
    margin-left: auto;
    order: 3;
  }

  .header-inner {
    justify-content: space-between;
    gap: 14px;
  }

  .header .brand,
  .site-header .brand {
    min-width: 0;
    flex: 1 1 auto;
  }

  .site-header .nav,
  .site-header .global-nav,
  .header .nav,
  .header .global-nav {
    position: fixed;
    top: var(--mobile-nav-top, 70px);
    left: 0;
    right: 0;
    z-index: 60;
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    max-height: calc(100vh - var(--mobile-nav-top, 70px));
    overflow: auto;
    padding: 12px 20px 24px;
    background: rgba(255, 255, 255, 0.98);
    border-bottom: 1px solid rgba(31, 77, 58, 0.15);
    box-shadow: 0 10px 24px rgba(20, 48, 42, 0.08);
  }

  .header .header-actions,
  .site-header .header-actions,
  .header-inner > a.btn,
  .header-inner > .header-button {
    display: none;
  }

  body.is-nav-open .site-header .nav,
  body.is-nav-open .site-header .global-nav,
  body.is-nav-open .header .nav,
  body.is-nav-open .header .global-nav {
    display: flex;
  }

  .site-header .nav a,
  .site-header .global-nav a,
  .header .nav a,
  .header .global-nav a {
    width: 100%;
    padding: 12px 0;
    border-bottom: 1px solid rgba(31, 77, 58, 0.08);
  }

  .site-header .nav a:last-child,
  .site-header .global-nav a:last-child,
  .header .nav a:last-child,
  .header .global-nav a:last-child {
    border-bottom: 0;
  }
}

@media (max-width: 768px) {
  .btn.btn--block {
    width: 100%;
  }
}

/* blog.html 一覧: 1ページ6件表示。広い〜mdは2カラム、480px以下は1カラムで縦積み */
@media (max-width: 480px) {
  #blog #article-grid.grid {
    grid-template-columns: 1fr;
    gap: 12px;
  }
}