/** ManaBase のヘッダー、サイドバー、本文枠、レスポンシブ配置。 */
.site-header {
  position: sticky;
  z-index: 30;
  top: 0;
  display: grid;
  grid-template-columns: 220px 1fr auto;
  min-height: var(--header-height);
  align-items: center;
  gap: 24px;
  padding: 0 max(24px, calc((100% - 1120px) / 2));
  border-bottom: 1px solid var(--line);
  background: var(--paper);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  width: max-content;
  color: var(--brand);
  font-size: 1.1rem;
  font-weight: 850;
  text-decoration: none;
}

.brand-mark {
  width: 44px;
  height: 44px;
  flex: 0 0 auto;
}

.header-nav { display: flex; align-items: center; gap: 24px; }

.header-nav a {
  display: inline-flex;
  min-height: var(--header-height);
  align-items: center;
  border-block: 3px solid transparent;
  color: var(--ink-soft);
  font-size: 0.88rem;
  font-weight: 700;
  text-decoration: none;
}

.header-nav a:hover { color: var(--brand); }
.header-nav a[aria-current="page"] { border-bottom-color: var(--accent); color: var(--brand); font-weight: 800; }

.grade-menu { position: relative; border-top: 0; }
.grade-menu summary {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 7px 0;
  color: var(--ink-soft);
  font-size: 0.88rem;
  font-weight: 700;
  cursor: pointer;
  list-style: none;
}

.brand > span:last-child { display: grid; line-height: 1.15; }
.brand > span:last-child strong { font-family: "Georgia", serif; font-size: 1.5rem; letter-spacing: -0.04em; }
.brand > span:last-child small { margin-top: 5px; color: var(--ink-soft); font-size: 0.63rem; font-weight: 600; letter-spacing: 0.04em; }
.grade-menu summary::-webkit-details-marker { display: none; }
.grade-menu summary::after { content: "⌄"; color: var(--brand); font-size: 0.8rem; }
.grade-menu[open] summary { color: var(--brand); }
.grade-menu[open] summary::after { transform: rotate(180deg); }
.grade-menu-items {
  position: absolute;
  z-index: 35;
  top: calc(100% + 8px);
  left: 50%;
  display: grid;
  min-width: 148px;
  gap: 4px;
  padding: 8px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: var(--paper);
  box-shadow: var(--shadow);
  transform: translateX(-50%);
}
.grade-menu-items a {
  display: block;
  padding: 8px 10px;
  border-radius: var(--radius-sm);
  color: var(--ink-soft);
  font-size: 0.82rem;
  white-space: nowrap;
}
.grade-menu-items a:hover { color: var(--brand); background: var(--surface-soft); }

.app-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  min-height: calc(100vh - var(--header-height));
}
.app-layout.has-sidebar { grid-template-columns: 250px minmax(0, 1fr); }

.course-sidebar {
  position: sticky;
  top: var(--header-height);
  display: flex;
  height: calc(100vh - var(--header-height));
  flex-direction: column;
  padding: 28px 18px 22px;
  border-right: 1px solid var(--line);
  background: var(--paper);
  overflow-y: auto;
}

.course-heading {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 0 8px 22px;
  border-bottom: 1px solid var(--line);
}

.course-symbol {
  display: grid;
  width: 42px;
  height: 42px;
  place-items: center;
  border-radius: var(--radius-md);
  color: #fff;
  background: var(--subject-accent);
  font-family: var(--font-math);
  font-size: 1.25rem;
  font-style: italic;
}

.course-sidebar[data-subject="math"] { --subject-accent: #2768a2; }
.course-sidebar[data-subject="science"] { --subject-accent: #28784e; }
.course-sidebar[data-subject="japanese"] { --subject-accent: #a44a63; }
.course-sidebar[data-subject="english"] { --subject-accent: #8a5a20; }
.course-sidebar[data-subject="social"] { --subject-accent: #6a559a; }

.course-heading small,
.course-heading strong { display: block; }
.course-heading small { color: var(--ink-soft); font-size: 0.76rem; }
.course-heading strong { font-size: 1rem; }

.stage-nav { display: grid; gap: 5px; margin-top: 18px; }

.stage-nav a {
  display: grid;
  grid-template-columns: 34px 1fr auto;
  align-items: center;
  min-height: 48px;
  gap: 7px;
  padding: 7px 9px;
  border-left: 3px solid transparent;
  border-radius: var(--radius-sm);
  color: var(--ink-soft);
  text-decoration: none;
}

.stage-nav a:hover { color: var(--ink); background: rgba(255, 255, 255, 0.65); }
.stage-nav a.is-current { border-left-color: var(--accent); color: var(--brand-deep); background: var(--brand-soft); }
.stage-nav a > span { font-family: var(--font-math); font-size: 0.78rem; }
.stage-nav a strong { font-size: 0.88rem; }
.stage-nav a small { font-size: 0.68rem; }

.sidebar-progress { margin-top: auto; padding: 18px 8px 0; border-top: 1px solid var(--line); }
.sidebar-progress > div:first-child { display: flex; justify-content: space-between; gap: 10px; font-size: 0.74rem; }
.sidebar-progress > div:first-child span { color: var(--brand); font-weight: 800; }
.sidebar-progress p { margin: 9px 0 0; color: var(--ink-soft); font-size: 0.7rem; line-height: 1.5; }
.sidebar-progress p.is-error { color: var(--danger); }

.main-content {
  width: 100%;
  min-width: 0;
  max-width: 1240px;
  margin: 0 auto;
  padding: 40px clamp(24px, 4vw, 60px) 80px;
}

.site-footer {
  display: grid;
  justify-items: center;
  gap: 8px;
  padding: 24px clamp(26px, 5vw, 72px) 32px;
  border-top: 1px solid var(--line);
  color: var(--ink-soft);
  font-size: 0.78rem;
  text-align: center;
}

.site-footer__links {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 8px 18px;
}

.site-footer__links a {
  color: var(--brand-deep);
  font-weight: 800;
  text-underline-offset: 3px;
}

.site-footer p { margin: 0; }

.app-screen { width: 100%; }
.textbook-page,
.quiz-page { max-width: 880px; margin: 0 auto; }

.mobile-nav { display: none; }

@media (max-width: 920px) {
  .site-header { grid-template-columns: 220px 1fr auto; padding: 0 18px; }
  .header-nav { gap: 15px; }
  .app-layout.has-sidebar { grid-template-columns: 220px minmax(0, 1fr); }
  .course-sidebar { padding-inline: 12px; }
  .main-content { padding: 28px 28px 90px; }
}

@media (max-width: 820px) {
  :root { --header-height: 64px; }
  .site-header { grid-template-columns: 1fr auto; }
  .brand-mark { width: 38px; height: 38px; }
  .header-nav { display: none; }
  .site-header .icon-text-button { min-width: 44px; min-height: 44px; padding: 9px; }
  .site-header .icon-text-button > span:last-child { display: none; }
  .app-layout { display: block; min-height: auto; }
  .course-sidebar { display: none; }
  .main-content { padding: 22px 18px 90px; }
  .site-footer { padding: 20px 18px 82px; }
  .mobile-nav {
    position: fixed;
    z-index: 25;
    right: 0;
    bottom: 0;
    left: 0;
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    min-height: 66px;
    padding-bottom: env(safe-area-inset-bottom, 0px);
    border-top: 1px solid var(--line);
    background: rgba(255, 255, 255, 0.98);
  }
  .mobile-nav a,
  .mobile-nav button {
    display: grid;
    place-content: center;
    gap: 1px;
    min-width: 0;
    border: 0;
    color: var(--ink-soft);
    background: transparent;
    font-size: 0.66rem;
    text-align: center;
    text-decoration: none;
  }
  .mobile-nav a { border-top: 3px solid transparent; }
  .mobile-nav a[aria-current="page"] { border-top-color: var(--accent); color: var(--brand); background: var(--brand-soft); font-weight: 800; }
  .mobile-nav .ui-icon { margin: 0 auto 3px; }
}

@media print {
  .site-header,
  .course-sidebar,
  .mobile-nav,
  .lesson-actions,
  .icon-text-button { display: none !important; }
  .app-layout { display: block; }
  .main-content { max-width: none; padding: 0; }
  .app-screen[hidden] { display: none !important; }
  body { color: #000; background: #fff; }
}