/* 语法书页样式,沿用 style.css 的绿色主题变量 */
.grammar-grid {
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 18px;
  align-items: start;
}
.grammar-toc {
  position: sticky;
  top: 12px;
  max-height: calc(100vh - 90px);
  overflow-y: auto;
  background: var(--card, #fff);
  border-radius: 10px;
  padding: 12px 10px;
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.06);
  font-size: 14px;
}
.toc-part-title {
  font-weight: 700;
  color: var(--green-dark, #4a9d5b);
  margin: 10px 4px 4px;
  font-size: 13px;
}
.toc-ch > summary {
  cursor: pointer;
  padding: 4px 6px;
  border-radius: 6px;
  color: var(--text, #222);
  list-style: none;
}
.toc-ch > summary::-webkit-details-marker { display: none; }
.toc-ch > summary::before { content: "▸ "; color: var(--muted, #999); }
.toc-ch[open] > summary::before { content: "▾ "; }
.toc-ch > summary:hover { background: var(--hl, #eef7ef); }
.grammar-toc ul { list-style: none; margin: 2px 0 6px; padding-left: 14px; }
.grammar-toc li a {
  display: block;
  padding: 3px 6px;
  color: #555;
  text-decoration: none;
  border-radius: 5px;
  font-size: 13px;
}
.grammar-toc li a:hover { background: var(--hl, #eef7ef); color: var(--green-dark, #4a9d5b); }

.grammar-content {
  background: var(--card, #fff);
  border-radius: 10px;
  padding: 20px 26px;
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.06);
  min-height: 60vh;
  line-height: 1.75;
}
.g-chapter-head { border-bottom: 2px solid var(--hl, #e3f1e5); margin-bottom: 14px; padding-bottom: 8px; }
.g-part-tag { font-size: 12px; color: var(--muted, #999); }
.g-chapter-head h2 { margin: 4px 0 0; color: var(--green-dark, #4a9d5b); }
.g-section { margin: 18px 0; scroll-margin-top: 12px; }
.g-section-title {
  font-size: 16px;
  color: var(--text, #222);
  border-left: 4px solid var(--green, #7bc47f);
  padding-left: 10px;
  margin: 0 0 8px;
}
.g-section-title small { color: var(--muted, #aaa); font-weight: 400; font-size: 12px; }
.g-p { margin: 8px 0; color: #333; }
.g-ex {
  margin: 8px 0;
  padding: 8px 12px;
  background: #f7fbf7;
  border-radius: 8px;
  border-left: 3px solid var(--green, #7bc47f);
}
.g-ex-en { font-weight: 600; color: #1f3a26; }
.g-ex-zh { color: #555; font-size: 14px; margin-top: 2px; }
.g-ex-note { color: var(--muted, #888); font-size: 13px; margin-top: 2px; }
.g-concepts { margin: 6px 0 10px; }
.g-concept {
  display: inline-block;
  background: var(--hl, #e3f1e5);
  color: var(--green-dark, #4a9d5b);
  border-radius: 12px;
  padding: 2px 10px;
  font-size: 12px;
  margin: 0 6px 6px 0;
}
.g-flash { animation: gflash 1.6s ease; }
@keyframes gflash {
  0% { background: #fff6cc; }
  100% { background: transparent; }
}

/* 降级提示 + 骨架 */
.g-notice {
  background: #fff8e6;
  border: 1px solid #f0d98a;
  border-radius: 10px;
  padding: 14px 18px;
  margin-bottom: 14px;
}
.g-notice code {
  display: block;
  background: #2b2b2b;
  color: #eaeaea;
  padding: 8px 12px;
  border-radius: 6px;
  margin: 8px 0;
  font-size: 13px;
  overflow-x: auto;
}
.g-notice-sub { color: var(--muted, #888); font-size: 13px; margin: 4px 0 0; }
.g-tag-skel { padding: 8px 0; border-bottom: 1px dashed #eee; }
.g-tag-skel b { color: var(--green-dark, #4a9d5b); margin-right: 10px; }
.g-tag-skel span { color: #555; font-size: 14px; }

/* 窄屏:目录变抽屉 */
.grammar-mobilebar { display: none; }
@media (max-width: 900px) {
  .grammar-grid { grid-template-columns: 1fr; }
  .grammar-mobilebar {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 10px;
  }
  #toc-toggle {
    background: var(--green, #7bc47f);
    color: #fff;
    border: none;
    border-radius: 6px;
    padding: 6px 12px;
    cursor: pointer;
  }
  .grammar-crumb { font-size: 13px; color: var(--muted, #777); }
  .grammar-toc {
    display: none;
    position: fixed;
    top: 0; left: 0; bottom: 0;
    z-index: 50;
    width: 82%;
    max-width: 320px;
    max-height: 100vh;
    border-radius: 0;
  }
  body.toc-open .grammar-toc { display: block; }
}