/* ============================================================
   KRONOS ZHOU · 化学库 · 样式
   路径：knowledgelibrary/chemistry/chemistry.css
   ------------------------------------------------------------
   与 app-redirect.css 同一套皮：深色玻璃卡片 + accent 蓝。
   类名统一 chem- 前缀，不和列表页的 know-*、重定向库的 app-* 打架。
   这个库是**数据库型**：卡片墙 + 详情容器（元素/化合物/原理共用一套卡片）。
   ============================================================ */

/* ⚠️ 覆盖 main-page.css 里 .app-root 的 grid 布局 */
html body .app-root {
  display: flex !important;
  flex-direction: column !important;
  height: auto !important;
  min-height: 100vh;
  grid-template-rows: none !important;
}

/* ============================================================
   [hidden] 兜底（重要，别删）
   ------------------------------------------------------------
   .chem-dialog { display: flex } 这类规则能盖掉浏览器默认的
   [hidden] { display: none }，弹层就会一进页面就露出来。
   ============================================================ */
[hidden] {
  display: none !important;
}

/* ============================================================
   页面标题
   ============================================================ */
.page-hero {
  margin: 1.6rem 0 1.2rem;
  padding: 2.4rem 2rem;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-soft);
  background:
    radial-gradient(circle at 15% 25%, rgba(74, 222, 128, 0.13), transparent 55%),
    radial-gradient(circle at 85% 75%, rgba(91, 141, 239, 0.16), transparent 55%),
    var(--bg-block);
  box-shadow: var(--shadow-block);
  position: relative;
  overflow: hidden;
}

.page-hero::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(140deg, rgba(255, 255, 255, 0.04), transparent 40%);
  pointer-events: none;
}

.page-hero-title {
  font-family: 'Bahnschrift', 'Segoe UI Variable', 'Segoe UI', sans-serif;
  font-size: 2.4rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  background: linear-gradient(120deg, var(--text-primary) 20%, #4ade80 120%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  text-shadow: 0 0 30px var(--accent-glow);
  margin-bottom: 0.4rem;
}

.page-hero-subtitle {
  font-size: 0.95rem;
  font-weight: 500;
  letter-spacing: 0.26em;
  color: var(--text-muted);
  text-transform: uppercase;
}

.chem-hero-desc {
  margin-top: 1rem;
  font-size: 0.92rem;
  line-height: 1.7;
  color: var(--text-secondary);
  max-width: 54rem;
}

.chem-hero-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 1.1rem;
}

.chem-hero-tag {
  display: inline-block;
  padding: 0.28rem 0.7rem;
  border-radius: 999px;
  border: 1px solid var(--border-medium);
  background: var(--accent-soft);
  color: var(--text-secondary);
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  font-variant-numeric: tabular-nums;
}

/* ============================================================
   第一部分切换（全部 / 元素 / 化合物 / 原理）
   ============================================================ */
.chem-parts {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(9rem, 1fr));
  gap: 0.7rem;
  margin-bottom: 1.1rem;
}

.chem-part {
  appearance: none;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 0.25rem;
  padding: 0.85rem 1rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-soft);
  background: var(--bg-block);
  color: var(--text-secondary);
  font: inherit;
  cursor: pointer;
  text-align: left;
  transition: var(--transition);
}

.chem-part:hover {
  border-color: var(--accent);
  color: var(--text-primary);
  transform: translateY(-1px);
}

.chem-part.active {
  border-color: var(--accent);
  background: linear-gradient(160deg, var(--accent-soft), transparent 70%), var(--bg-elevated);
  color: var(--text-primary);
  box-shadow: 0 0 0 1px var(--accent-soft), 0 12px 26px -18px var(--accent-glow);
}

.chem-part-top {
  display: flex;
  align-items: center;
  gap: 0.45rem;
  font-size: 0.98rem;
  font-weight: 600;
  letter-spacing: 0.04em;
}

.chem-part-icon {
  font-size: 1.05rem;
  line-height: 1;
}

.chem-part-label {
  letter-spacing: 0.04em;
}

.chem-part-top .chem-chip-count {
  margin-left: auto;
}

.chem-part-meta {
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  font-variant-numeric: tabular-nums;
}

.chem-part.active .chem-part-meta {
  color: var(--text-secondary);
}

/* ============================================================
   工具栏
   ============================================================ */
.chem-toolbar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1.2rem;
  padding: 1rem 1.2rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-soft);
  background: var(--bg-block);
  box-shadow: var(--shadow-block);
}

/* 搜索框 */
.chem-search-box {
  position: relative;
  display: flex;
  align-items: center;
  flex: 1 1 20rem;
  min-width: 15rem;
}

.chem-search-icon {
  position: absolute;
  left: 0.9rem;
  font-size: 0.9rem;
  opacity: 0.7;
  pointer-events: none;
}

.chem-search-input {
  width: 100%;
  padding: 0.62rem 2.4rem;
  border-radius: 999px;
  border: 1px solid var(--border-medium);
  background: var(--bg-elevated);
  color: var(--text-primary);
  font: inherit;
  font-size: 0.9rem;
  transition: border-color 0.25s ease, box-shadow 0.25s ease;
}

.chem-search-input::placeholder {
  color: var(--text-muted);
}

.chem-search-input:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft);
}

.chem-search-clear {
  position: absolute;
  right: 0.6rem;
  appearance: none;
  border: none;
  background: transparent;
  color: var(--text-muted);
  cursor: pointer;
  font-size: 0.85rem;
  padding: 0.2rem 0.4rem;
  border-radius: 999px;
  transition: color 0.25s ease, background 0.25s ease;
}

.chem-search-clear:hover {
  color: var(--text-primary);
  background: var(--bg-block-hover);
}

/* 有机 / 无机 子切换 */
.chem-sublist {
  display: inline-flex;
  padding: 0.2rem;
  border-radius: 999px;
  border: 1px solid var(--border-soft);
  background: var(--bg-elevated);
}

.chem-sub {
  appearance: none;
  border: none;
  background: transparent;
  color: var(--text-secondary);
  font: inherit;
  font-size: 0.8rem;
  padding: 0.35rem 1rem;
  border-radius: 999px;
  cursor: pointer;
  transition: var(--transition);
  font-variant-numeric: tabular-nums;
}

.chem-sub:hover {
  color: var(--text-primary);
}

.chem-sub.active {
  background: var(--accent);
  color: #fff;
  box-shadow: 0 6px 16px -10px var(--accent-glow);
}

/* chip 行 */
.chem-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
  flex: 1 1 100%;
}

.chem-chip {
  appearance: none;
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.32rem 0.8rem;
  border-radius: 999px;
  border: 1px solid var(--border-soft);
  background: var(--bg-elevated);
  color: var(--text-secondary);
  font: inherit;
  font-size: 0.76rem;
  letter-spacing: 0.02em;
  cursor: pointer;
  transition: var(--transition);
}

.chem-chip:hover {
  border-color: var(--accent);
  color: var(--text-primary);
  transform: translateY(-1px);
}

.chem-chip.active {
  border-color: var(--accent);
  background: var(--accent-soft);
  color: var(--accent);
}

.chem-chip-count {
  font-size: 0.68rem;
  font-variant-numeric: tabular-nums;
  padding: 0.05rem 0.36rem;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.06);
}

.chem-chip.active .chem-chip-count {
  background: rgba(91, 141, 239, 0.25);
}

/* 学段 chip 单独一套配色：四个学段各一色 */
.chem-chip[data-level="高中"].active {
  border-color: rgba(74, 222, 128, 0.6);
  background: var(--success-soft);
  color: var(--success);
}

.chem-chip[data-level="高中"].active .chem-chip-count {
  background: rgba(74, 222, 128, 0.22);
}

.chem-chip[data-level="研究生"].active {
  border-color: rgba(168, 121, 240, 0.6);
  background: rgba(168, 121, 240, 0.15);
  color: #b795f5;
}

.chem-chip[data-level="研究生"].active .chem-chip-count {
  background: rgba(168, 121, 240, 0.22);
}

.chem-chip[data-level="博硕"].active {
  border-color: rgba(245, 158, 11, 0.6);
  background: var(--warn-soft);
  color: var(--warn);
}

.chem-chip[data-level="博硕"].active .chem-chip-count {
  background: rgba(245, 158, 11, 0.22);
}

/* 工具行底部 */
.chem-toolbar-foot {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.7rem;
  flex: 1 1 100%;
  padding-top: 0.7rem;
  border-top: 1px dashed var(--border-soft);
}

.chem-sort {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
}

.chem-sort-label {
  font-size: 0.74rem;
  color: var(--text-muted);
  letter-spacing: 0.08em;
}

.chem-sort-select {
  appearance: none;
  padding: 0.36rem 1.6rem 0.36rem 0.7rem;
  border-radius: 999px;
  border: 1px solid var(--border-medium);
  background: var(--bg-elevated)
    url("data:image/svg+xml;charset=utf-8,%3Csvg xmlns='http://www.w3.org/2000/svg' width='10' height='6'%3E%3Cpath d='M1 1l4 4 4-4' fill='none' stroke='%2364718a' stroke-width='1.6'/%3E%3C/svg%3E")
    no-repeat right 0.65rem center;
  color: var(--text-secondary);
  font: inherit;
  font-size: 0.78rem;
  cursor: pointer;
  transition: var(--transition);
}

.chem-sort-select:hover,
.chem-sort-select:focus {
  border-color: var(--accent);
  color: var(--text-primary);
  outline: none;
}

.chem-reset {
  appearance: none;
  padding: 0.4rem 1rem;
  border-radius: 999px;
  border: 1px solid var(--border-medium);
  background: var(--bg-elevated);
  color: var(--text-secondary);
  font: inherit;
  font-size: 0.78rem;
  cursor: pointer;
  transition: var(--transition);
  white-space: nowrap;
}

.chem-reset:hover {
  border-color: var(--accent);
  color: var(--text-primary);
}

.chem-reset:active {
  transform: scale(0.97);
}

.chem-count {
  margin-left: auto;
  font-size: 0.78rem;
  color: var(--text-muted);
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
}

/* ============================================================
   卡片墙
   ============================================================ */
.chem-grid-section {
  margin-bottom: 2rem;
}

.chem-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(16.5rem, 1fr));
  gap: 0.9rem;
}

.chem-card {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 0.55rem;
  padding: 1rem 1.05rem 0.9rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-soft);
  background: var(--bg-block);
  box-shadow: var(--shadow-block);
  cursor: pointer;
  overflow: hidden;
  transition: border-color 0.26s ease, box-shadow 0.26s ease, transform 0.26s ease;
}

.chem-card::after {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: inherit;
  background: linear-gradient(140deg, rgba(255, 255, 255, 0.04), transparent 45%);
  pointer-events: none;
  opacity: 0.6;
  transition: opacity 0.26s ease;
}

.chem-card:hover {
  border-color: var(--accent);
  transform: translateY(-3px);
  box-shadow: 0 0 0 1px var(--accent-soft), 0 16px 32px -16px var(--accent-glow);
}

.chem-card:hover::after {
  opacity: 1;
}

.chem-card:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

/* 卡片头部：化学式徽标 + 分类 */
.chem-card-top {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 0.6rem;
  position: relative;
  z-index: 1;
}

.chem-formula {
  display: inline-flex;
  align-items: center;
  padding: 0.28rem 0.6rem;
  border-radius: 0.55rem;
  border: 1px solid var(--border-medium);
  background: var(--bg-elevated);
  color: var(--text-primary);
  font-family: 'Cascadia Mono', 'Consolas', 'Segoe UI', monospace;
  font-size: 1.02rem;
  font-weight: 600;
  letter-spacing: 0.01em;
  line-height: 1.35;
  max-width: 12rem;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.chem-formula sub {
  font-size: 0.62em;
  color: var(--text-secondary);
}

.chem-formula sup {
  font-size: 0.62em;
  color: var(--text-secondary);
}

.chem-card-top .chem-formula {
  flex-shrink: 0;
}

/* 元素卡片：序号小方块 */
.chem-z {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 2.2rem;
  height: 2.2rem;
  padding: 0 0.35rem;
  border-radius: 0.55rem;
  border: 1px solid var(--border-medium);
  background: var(--bg-elevated);
  color: var(--text-muted);
  font-size: 0.78rem;
  font-variant-numeric: tabular-nums;
}

/* 分类 / 分组标签 */
.chem-tag {
  display: inline-flex;
  align-items: center;
  padding: 0.2rem 0.6rem;
  border-radius: 999px;
  font-size: 0.68rem;
  font-weight: 500;
  letter-spacing: 0.04em;
  white-space: nowrap;
  flex-shrink: 0;
  border: 1px solid var(--border-soft);
  background: var(--bg-elevated);
  color: var(--text-secondary);
}

.chem-tag-group-inorganic {
  background: rgba(45, 212, 191, 0.13);
  color: #4fd1c5;
  border-color: rgba(45, 212, 191, 0.3);
}

.chem-tag-group-organic {
  background: rgba(168, 121, 240, 0.14);
  color: #b795f5;
  border-color: rgba(168, 121, 240, 0.3);
}

.chem-tag-element {
  background: var(--accent-soft);
  color: var(--accent);
  border-color: rgba(91, 141, 239, 0.35);
}

.chem-tag-principle {
  background: rgba(245, 158, 11, 0.12);
  color: var(--warn);
  border-color: rgba(245, 158, 11, 0.25);
}

/* 名称 */
.chem-card-titles {
  display: flex;
  flex-direction: column;
  gap: 0.1rem;
  min-width: 0;
  position: relative;
  z-index: 1;
}

.chem-card-name {
  font-size: 1.02rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  color: var(--text-primary);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.chem-card-name-en {
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  color: var(--text-muted);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

/* 卡片里的关键数据（相对分子质量 / 熔点 / 位置…） */
.chem-card-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.3rem 0.55rem;
  position: relative;
  z-index: 1;
  font-size: 0.72rem;
  color: var(--text-muted);
  font-variant-numeric: tabular-nums;
}

.chem-card-meta-item {
  display: inline-flex;
  gap: 0.25rem;
  max-width: 100%;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.chem-card-meta-k {
  color: var(--text-muted);
  opacity: 0.75;
}

.chem-card-meta-v {
  color: var(--text-secondary);
}

.chem-card-desc {
  margin: 0;
  font-size: 0.82rem;
  line-height: 1.65;
  color: var(--text-secondary);
  position: relative;
  z-index: 1;
  flex: 1 1 auto;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

/* 卡脚：学段 + 详情 */
.chem-card-foot {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  padding-top: 0.6rem;
  border-top: 1px solid var(--border-soft);
  position: relative;
  z-index: 1;
}

.chem-levels {
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem;
}

.chem-level {
  display: inline-flex;
  align-items: center;
  padding: 0.14rem 0.45rem;
  border-radius: 0.35rem;
  font-size: 0.64rem;
  letter-spacing: 0.04em;
  border: 1px solid var(--border-soft);
  background: var(--bg-elevated);
  color: var(--text-muted);
  white-space: nowrap;
}

.chem-level-0 {
  color: var(--success);
  border-color: rgba(74, 222, 128, 0.28);
  background: var(--success-soft);
}

.chem-level-1 {
  color: var(--accent);
  border-color: rgba(91, 141, 239, 0.32);
  background: var(--accent-soft);
}

.chem-level-2 {
  color: #b795f5;
  border-color: rgba(168, 121, 240, 0.3);
  background: rgba(168, 121, 240, 0.13);
}

.chem-level-3 {
  color: var(--warn);
  border-color: rgba(245, 158, 11, 0.28);
  background: var(--warn-soft);
}

.chem-card-open {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  padding: 0.32rem 0.7rem;
  border-radius: 999px;
  border: 1px solid var(--border-medium);
  background: var(--bg-elevated);
  color: var(--text-secondary);
  font-size: 0.72rem;
  flex-shrink: 0;
  transition: var(--transition);
}

.chem-card:hover .chem-card-open {
  border-color: var(--accent);
  color: var(--accent);
}

.chem-card-open::after {
  content: '›';
  font-size: 0.9rem;
}

/* ============================================================
   空状态 / 显示更多
   ============================================================ */
.chem-empty {
  text-align: center;
  color: var(--text-muted);
  font-size: 0.95rem;
  font-style: italic;
  padding: 3rem 1rem;
  background: var(--bg-block);
  border: 1px dashed var(--border-soft);
  border-radius: var(--radius-md);
}

.chem-more-wrap {
  display: flex;
  justify-content: center;
  margin-top: 1.4rem;
}

.chem-more {
  appearance: none;
  padding: 0.6rem 1.6rem;
  border-radius: 999px;
  border: 1px solid var(--accent);
  background: var(--accent-soft);
  color: var(--accent);
  font: inherit;
  font-size: 0.82rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  font-variant-numeric: tabular-nums;
}

.chem-more:hover {
  background: var(--accent);
  color: #fff;
}

.chem-more:active {
  transform: scale(0.98);
}

/* ============================================================
   说明区
   ============================================================ */
.chem-note {
  margin-bottom: 2.4rem;
  padding: 1.1rem 1.3rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-soft);
  background: var(--bg-block);
  box-shadow: var(--shadow-block);
}

.chem-note-title {
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--text-secondary);
  margin-bottom: 0.5rem;
}

.chem-note-text {
  font-size: 0.8rem;
  line-height: 1.85;
  color: var(--text-muted);
}

.chem-note-text strong {
  color: var(--text-secondary);
}

.chem-note-text code {
  padding: 0.05rem 0.35rem;
  border-radius: 0.35rem;
  border: 1px solid var(--border-soft);
  background: var(--bg-elevated);
  color: var(--text-secondary);
  font-size: 0.74rem;
  font-family: 'Cascadia Mono', 'Consolas', monospace;
}

.chem-note-text + .chem-note-text {
  margin-top: 0.5rem;
  padding-top: 0.5rem;
  border-top: 1px dashed var(--border-soft);
}

/* ============================================================
   详情容器
   ============================================================ */
.chem-dialog {
  position: fixed;
  inset: 0;
  z-index: 70;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1.2rem;
}

html.chem-dialog-open {
  overflow: hidden;
}

.chem-dialog-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(6, 8, 12, 0.72);
  backdrop-filter: blur(3px);
}

.chem-dialog-panel {
  position: relative;
  width: min(42rem, 100%);
  max-height: min(86vh, 48rem);
  display: flex;
  flex-direction: column;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-medium);
  background: var(--bg-panel-solid);
  box-shadow: var(--shadow-panel);
  animation: chem-dialog-in 0.26s cubic-bezier(0.2, 0.9, 0.4, 1);
  overflow: hidden;
}

@keyframes chem-dialog-in {
  from { transform: translateY(1rem) scale(0.98); opacity: 0.4; }
  to { transform: translateY(0) scale(1); opacity: 1; }
}

.chem-dialog-close {
  position: absolute;
  top: 0.75rem;
  right: 0.8rem;
  z-index: 2;
  width: 2rem;
  height: 2rem;
  border-radius: 50%;
  border: 1px solid var(--border-soft);
  background: var(--bg-elevated);
  color: var(--text-secondary);
  font: inherit;
  font-size: 0.85rem;
  cursor: pointer;
  transition: var(--transition);
}

.chem-dialog-close:hover {
  color: var(--text-primary);
  border-color: var(--accent);
}

.chem-dialog-body {
  flex: 1 1 auto;
  overflow-y: auto;
  padding: 1.4rem 1.4rem 1.2rem;
}

/* 详情头部 */
.chem-dialog-head {
  display: flex;
  align-items: center;
  gap: 0.9rem;
  padding-right: 2.4rem;
  flex-wrap: wrap;
}

.chem-dialog-head .chem-formula {
  font-size: 1.3rem;
  padding: 0.4rem 0.8rem;
  max-width: 100%;
}

.chem-dialog-head .chem-z {
  height: 2.6rem;
}

.chem-dialog-titles {
  display: flex;
  flex-direction: column;
  gap: 0.12rem;
  min-width: 0;
  flex: 1 1 10rem;
}

.chem-dialog-name {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: 0.02em;
}

.chem-dialog-name-en {
  font-size: 0.76rem;
  letter-spacing: 0.08em;
  color: var(--text-muted);
}

.chem-dialog-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  flex: 1 1 100%;
}

.chem-dialog-desc {
  margin: 0.95rem 0 0;
  font-size: 0.86rem;
  line-height: 1.75;
  color: var(--text-secondary);
}

.chem-dialog-aka {
  margin-top: 0.6rem;
  font-size: 0.78rem;
  line-height: 1.7;
  color: var(--text-muted);
}

.chem-dialog-aka strong {
  color: var(--text-secondary);
}

/* 详情分区 */
.chem-dialog-section {
  margin-top: 1.1rem;
  padding-top: 0.9rem;
  border-top: 1px solid var(--border-soft);
}

.chem-dialog-section-title {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.76rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  color: var(--text-secondary);
  margin-bottom: 0.6rem;
}

.chem-dialog-section-title::before {
  content: '';
  width: 0.28rem;
  height: 0.9rem;
  border-radius: 999px;
  background: var(--accent);
}

/* 结构化字段表 */
.chem-meta-table {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(13rem, 1fr));
  gap: 0.35rem 0.9rem;
}

.chem-meta-row {
  display: flex;
  align-items: baseline;
  gap: 0.5rem;
  padding: 0.32rem 0.5rem;
  border-radius: 0.5rem;
  background: var(--bg-block);
  border: 1px solid var(--border-soft);
  font-size: 0.78rem;
  line-height: 1.6;
}

.chem-meta-k {
  color: var(--text-muted);
  white-space: nowrap;
  flex-shrink: 0;
  font-size: 0.74rem;
}

.chem-meta-v {
  color: var(--text-secondary);
  word-break: break-word;
  font-variant-numeric: tabular-nums;
}

/* 列表：要点 / 反应 / 制备 */
.chem-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.chem-point {
  position: relative;
  padding: 0.4rem 0.6rem 0.4rem 1.5rem;
  border-radius: 0.5rem;
  background: var(--bg-block);
  border: 1px solid var(--border-soft);
  font-size: 0.8rem;
  line-height: 1.72;
  color: var(--text-secondary);
}

.chem-point::before {
  content: '·';
  position: absolute;
  left: 0.62rem;
  top: 0.36rem;
  font-size: 1.1rem;
  line-height: 1;
  color: var(--accent);
}

.chem-rxn {
  position: relative;
  padding: 0.45rem 0.7rem;
  border-radius: 0.5rem;
  background: var(--bg-elevated);
  border: 1px solid var(--border-soft);
  border-left: 2px solid var(--accent);
  font-family: 'Cascadia Mono', 'Consolas', 'Segoe UI', monospace;
  font-size: 0.8rem;
  line-height: 1.75;
  color: var(--text-primary);
  overflow-x: auto;
  white-space: pre-wrap;
  word-break: break-word;
}

.chem-rxn sub,
.chem-rxn sup {
  font-size: 0.65em;
  color: var(--text-secondary);
}

.chem-dialog-text {
  font-size: 0.82rem;
  line-height: 1.8;
  color: var(--text-secondary);
  padding: 0.45rem 0.65rem;
  border-radius: 0.5rem;
  background: var(--bg-block);
  border: 1px solid var(--border-soft);
}

.chem-dialog-text.is-safety {
  border-color: rgba(239, 68, 68, 0.3);
  background: var(--danger-soft);
  color: #fca5a5;
}

.chem-dialog-foot {
  margin-top: 1.1rem;
  padding-top: 0.9rem;
  border-top: 1px solid var(--border-soft);
  font-size: 0.7rem;
  color: var(--text-muted);
  line-height: 1.7;
}

/* ============================================================
   提示条
   ============================================================ */
.chem-toast {
  position: fixed;
  left: 50%;
  bottom: 1.6rem;
  transform: translate(-50%, 1rem);
  z-index: 80;
  padding: 0.6rem 1.1rem;
  border-radius: 999px;
  border: 1px solid var(--border-medium);
  background: var(--bg-panel-solid);
  color: var(--text-primary);
  font-size: 0.82rem;
  box-shadow: var(--shadow-panel);
  opacity: 0;
  transition: opacity 0.22s ease, transform 0.22s ease;
  pointer-events: none;
}

.chem-toast.show {
  opacity: 1;
  transform: translate(-50%, 0);
}

/* ============================================================
   页脚推到最底部
   ============================================================ */
.site-footer {
  margin-top: auto;
}

/* ============================================================
   响应式
   ============================================================ */
@media (max-width: 900px) {
  .page-hero {
    padding: 1.8rem 1.4rem;
  }

  .page-hero-title {
    font-size: 1.8rem;
  }

  .page-hero-subtitle {
    font-size: 0.8rem;
    letter-spacing: 0.2em;
  }

  .chem-toolbar {
    padding: 0.9rem 1rem;
  }

  .chem-count {
    margin-left: 0;
    width: 100%;
  }

  .chem-dialog {
    align-items: flex-end;
    padding: 0;
  }

  .chem-dialog-panel {
    width: 100%;
    max-height: 88vh;
    border-radius: var(--radius-lg) var(--radius-lg) 0 0;
    animation: chem-dialog-up 0.26s cubic-bezier(0.2, 0.9, 0.4, 1);
  }

  @keyframes chem-dialog-up {
    from { transform: translateY(100%); opacity: 0.6; }
    to { transform: translateY(0); opacity: 1; }
  }
}

@media (max-width: 520px) {
  .chem-grid {
    grid-template-columns: 1fr;
  }

  .chem-parts {
    grid-template-columns: repeat(2, 1fr);
  }

  .chem-dialog-body {
    padding: 1.2rem 1rem 1rem;
  }

  .chem-meta-table {
    grid-template-columns: 1fr;
  }
}