:root {
  --blue: #38b6ff;
  --blue-deep: #1e8fd6;
  --blue-bg: #e3f4ff;
  --orange: #ffb347;
  --orange-deep: #f0881f;
  --orange-bg: #fff1dd;
  --green: #66bb6a;
  --green-deep: #3e9b45;
  --green-bg: #e9f7e9;
  --yellow: #ffd966;
  --pink: #ff9eb5;
  --purple: #b39ddb;
  --ink: #33506b;
  --ink-light: #6d8aa5;
  --card: #ffffff;
  --shadow: 0 6px 18px rgba(56, 130, 190, 0.14);
  --shadow-big: 0 10px 28px rgba(56, 130, 190, 0.18);
  --radius: 22px;
  --radius-sm: 14px;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB",
    "Microsoft YaHei", "Noto Sans SC", "Segoe UI", sans-serif;
  background: linear-gradient(180deg, #eaf7ff 0%, #fdf7ec 70%, #fff6e8 100%);
  background-attachment: fixed;
  color: var(--ink);
  min-height: 100vh;
  line-height: 1.55;
  padding-bottom: 90px;
}

button {
  font-family: inherit;
  cursor: pointer;
}

input,
select {
  font-family: inherit;
  font-size: 1rem;
  color: var(--ink);
}

a {
  color: inherit;
  text-decoration: none;
}

.page {
  max-width: 980px;
  margin: 0 auto;
  padding: 16px 16px 30px;
}

/* ---------- 顶部导航 ---------- */
.topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 14px;
  background: rgba(255, 255, 255, 0.88);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 2px dashed var(--yellow);
}

.topbar h1 {
  flex: 1;
  font-size: 1.15rem;
  font-weight: 800;
  text-align: center;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.back-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--blue-bg);
  color: var(--blue-deep);
  font-size: 1.25rem;
  font-weight: 700;
  border: 2px solid var(--blue);
  transition: transform 0.15s;
}

.back-btn:active {
  transform: scale(0.9);
}

.topbar-space {
  width: 40px;
}

/* ---------- 底部标签导航 ---------- */
.bottom-nav {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 30;
  display: flex;
  justify-content: space-around;
  background: rgba(255, 255, 255, 0.96);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-top: 2px solid #e8f1fa;
  padding: 8px 6px calc(8px + env(safe-area-inset-bottom));
  box-shadow: 0 -4px 16px rgba(56, 130, 190, 0.1);
}

.bottom-nav a {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
  font-size: 0.8rem;
  color: var(--ink-light);
  padding: 4px 14px;
  border-radius: 16px;
  transition: color 0.15s, background 0.15s;
}

.bottom-nav a .nav-emoji {
  font-size: 1.35rem;
  line-height: 1.2;
}

.bottom-nav a.active {
  color: var(--blue-deep);
  font-weight: 700;
  background: var(--blue-bg);
}

/* ---------- 首页 hero ---------- */
.hero {
  text-align: center;
  padding: 30px 10px 18px;
}

.hero-emoji {
  font-size: 3.4rem;
  animation: float 3s ease-in-out infinite;
  display: inline-block;
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

.hero-title {
  font-size: 2rem;
  font-weight: 900;
  background: linear-gradient(90deg, var(--blue-deep), var(--orange-deep));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  margin-top: 8px;
}

.hero-sub {
  color: var(--ink-light);
  font-size: 1rem;
  margin-top: 6px;
}

/* ---------- 分类卡片 ---------- */
.grid-cards {
  display: grid;
  gap: 16px;
}

.home-cats {
  grid-template-columns: repeat(auto-fit, minmax(210px, 1fr));
  margin-top: 18px;
}

.category-card {
  display: flex;
  flex-direction: column;
  gap: 6px;
  background: var(--card);
  border-radius: var(--radius);
  padding: 22px 20px;
  box-shadow: var(--shadow);
  border-top: 8px solid var(--cat);
  transition: transform 0.18s, box-shadow 0.18s;
}

.category-card:active {
  transform: scale(0.97);
}

.category-card .cat-emoji {
  font-size: 2.6rem;
}

.category-card .cat-name {
  font-size: 1.45rem;
  font-weight: 800;
  color: var(--cat-deep);
}

.category-card .cat-desc {
  color: var(--ink-light);
  font-size: 0.95rem;
  flex: 1;
}

.category-card .cat-arrow {
  align-self: flex-end;
  font-size: 1.2rem;
  color: var(--cat-deep);
  font-weight: 800;
}

.cat-math { --cat: var(--blue); --cat-deep: var(--blue-deep); }
.cat-chinese { --cat: var(--orange); --cat-deep: var(--orange-deep); }
.cat-english { --cat: var(--green); --cat-deep: var(--green-deep); }

/* ---------- 模块卡片网格 ---------- */
.module-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(165px, 1fr));
  gap: 14px;
  margin-top: 14px;
}

.module-card {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 8px;
  background: var(--card);
  border-radius: var(--radius);
  padding: 18px 16px;
  box-shadow: var(--shadow);
  border: 2px solid transparent;
  transition: transform 0.18s, box-shadow 0.18s, border-color 0.18s;
}

.module-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-big);
  border-color: var(--cat);
}

.module-card:active {
  transform: scale(0.96);
}

.module-card .mod-emoji {
  font-size: 2.2rem;
}

.module-card .mod-name {
  font-size: 1.08rem;
  font-weight: 800;
}

.module-card .mod-desc {
  font-size: 0.85rem;
  color: var(--ink-light);
  flex: 1;
}

.module-card .mod-go {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--cat-deep);
  background: var(--cat-bg);
  padding: 4px 12px;
  border-radius: 999px;
}

.cat-math .module-card { --cat: var(--blue); --cat-deep: var(--blue-deep); --cat-bg: var(--blue-bg); }
.cat-chinese .module-card { --cat: var(--orange); --cat-deep: var(--orange-deep); --cat-bg: var(--orange-bg); }
.cat-english .module-card { --cat: var(--green); --cat-deep: var(--green-deep); --cat-bg: var(--green-bg); }

/* ---------- 通用卡片与区块 ---------- */
.card {
  background: var(--card);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 18px;
}

.section {
  margin-top: 22px;
}

.section-title {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 1.15rem;
  font-weight: 800;
  margin-bottom: 12px;
}

.section-title .t-emoji {
  font-size: 1.3rem;
}

.tip-card {
  margin-top: 18px;
  background: var(--yellow);
  border-radius: var(--radius);
  padding: 14px 18px;
  font-size: 0.95rem;
  font-weight: 600;
  color: #7a5a12;
}

/* ---------- 搜索框 ---------- */
.searchbox {
  display: flex;
  align-items: center;
  gap: 8px;
  background: #fff;
  border: 2px solid var(--blue);
  border-radius: 999px;
  padding: 6px 16px;
  box-shadow: var(--shadow);
}

.searchbox .s-emoji {
  font-size: 1.15rem;
}

.searchbox input {
  flex: 1;
  border: none;
  outline: none;
  background: transparent;
  font-size: 1rem;
  padding: 6px 0;
  min-width: 0;
}

/* ---------- 标签 / 筛选 ---------- */
.pill-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 14px 0 4px;
}

.pill {
  border: 2px solid var(--blue);
  background: #fff;
  color: var(--blue-deep);
  font-size: 0.9rem;
  font-weight: 700;
  padding: 6px 16px;
  border-radius: 999px;
  transition: background 0.15s, color 0.15s, transform 0.12s;
}

.pill:active {
  transform: scale(0.94);
}

.pill.active {
  background: var(--blue);
  color: #fff;
}

.pill.pill-orange { border-color: var(--orange); color: var(--orange-deep); }
.pill.pill-orange.active { background: var(--orange); color: #fff; }
.pill.pill-green { border-color: var(--green); color: var(--green-deep); }
.pill.pill-green.active { background: var(--green); color: #fff; }
.pill.pill-pink { border-color: var(--pink); color: #d85b78; }
.pill.pill-pink.active { background: var(--pink); color: #fff; }

.tag {
  display: inline-block;
  font-size: 0.78rem;
  font-weight: 700;
  padding: 2px 10px;
  border-radius: 999px;
  background: var(--blue-bg);
  color: var(--blue-deep);
}

.tag-orange { background: var(--orange-bg); color: var(--orange-deep); }
.tag-green { background: var(--green-bg); color: var(--green-deep); }

/* ---------- 按钮 / 输入 ---------- */
.btn {
  border: none;
  border-radius: 999px;
  background: linear-gradient(90deg, var(--blue), var(--blue-deep));
  color: #fff;
  font-size: 1rem;
  font-weight: 800;
  padding: 10px 24px;
  box-shadow: 0 4px 12px rgba(56, 130, 190, 0.3);
  transition: transform 0.12s;
}

.btn:active {
  transform: scale(0.95);
}

.btn-orange {
  background: linear-gradient(90deg, var(--orange), var(--orange-deep));
  box-shadow: 0 4px 12px rgba(240, 136, 31, 0.3);
}

.input, select.input {
  border: 2px solid #cfe3f3;
  border-radius: var(--radius-sm);
  padding: 10px 14px;
  font-size: 1rem;
  width: 100%;
  outline: none;
  background: #fff;
}

.input:focus {
  border-color: var(--blue);
}

.form-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  margin-top: 10px;
}

.form-row label {
  font-weight: 700;
  font-size: 0.95rem;
}

.num-input {
  width: 130px;
}

select.input {
  width: auto;
  min-width: 120px;
}

/* ---------- 结果框 ---------- */
.result-box {
  margin-top: 16px;
  background: linear-gradient(120deg, var(--blue-bg), #fff6e8);
  border: 3px dashed var(--blue);
  border-radius: var(--radius);
  padding: 18px;
  text-align: center;
}

.result-box .result-text {
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--blue-deep);
  word-break: break-all;
}

.result-box .result-sub {
  color: var(--ink-light);
  font-size: 0.9rem;
  margin-top: 4px;
}

/* ---------- 表格 ---------- */
.table-wrap {
  overflow-x: auto;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  background: #fff;
  margin-top: 12px;
}

table.kv {
  width: 100%;
  border-collapse: collapse;
  min-width: 420px;
}

table.kv th,
table.kv td {
  padding: 10px 12px;
  text-align: center;
  border-bottom: 2px solid #eef6fd;
  font-size: 0.95rem;
}

table.kv th {
  background: var(--blue-bg);
  color: var(--blue-deep);
  font-weight: 800;
}

table.kv tr:last-child td {
  border-bottom: none;
}

/* 乘法口诀表 */
.times-table {
  border-collapse: separate;
  border-spacing: 4px;
  width: max-content;
  margin: 0 auto;
}

.times-table td,
.times-table th {
  width: 46px;
  height: 46px;
  min-width: 34px;
  text-align: center;
  border-radius: 10px;
  font-size: 0.9rem;
  font-weight: 700;
}

.times-table th {
  background: var(--blue-bg);
  color: var(--blue-deep);
  font-size: 0.85rem;
}

.times-table td {
  background: #f2faff;
  cursor: pointer;
  border: 2px solid transparent;
  transition: all 0.12s;
  user-select: none;
}

.times-table td:hover {
  background: #d7f0ff;
  transform: scale(1.08);
}

.times-table td.selected {
  background: var(--orange);
  color: #fff;
  border-color: var(--orange-deep);
  transform: scale(1.1);
  box-shadow: 0 3px 8px rgba(240, 136, 31, 0.4);
}

.times-info {
  text-align: center;
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--orange-deep);
  background: var(--orange-bg);
  border-radius: var(--radius-sm);
  padding: 10px;
  margin-top: 12px;
  min-height: 48px;
}

/* 质数 / 数字格 */
.num-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(58px, 1fr));
  gap: 10px;
  margin-top: 12px;
}

.num-cell {
  background: linear-gradient(140deg, #eaf7ff, #fff6e8);
  border: 2px solid var(--blue);
  border-radius: var(--radius-sm);
  text-align: center;
  padding: 8px 4px;
  font-weight: 800;
  font-size: 1.05rem;
  color: var(--blue-deep);
}

.num-cell small {
  display: block;
  font-size: 0.75rem;
  color: var(--orange-deep);
  font-weight: 700;
}

/* ---------- 图形公式 ---------- */
.shape-card {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.shape-card .shape-svg {
  background: #f7fcff;
  border: 2px dashed #cfe3f3;
  border-radius: var(--radius-sm);
  padding: 6px;
  text-align: center;
}

.shape-card .shape-svg svg {
  max-width: 100%;
  height: auto;
}

.shape-head {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 1.15rem;
  font-weight: 800;
}

.formula-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.formula-item {
  background: var(--blue-bg);
  border-radius: var(--radius-sm);
  padding: 8px 12px;
  font-size: 0.95rem;
}

.formula-item b {
  color: var(--blue-deep);
}

.formula-item .f-formula {
  display: block;
  font-family: "Courier New", Consolas, monospace;
  font-weight: 800;
  font-size: 1rem;
  margin-top: 2px;
}

.shape-example {
  background: #fff8ec;
  border-radius: var(--radius-sm);
  padding: 8px 12px;
  font-size: 0.92rem;
  color: #8a6410;
}

.shape-example b {
  color: var(--orange-deep);
}

/* ---------- 古诗 ---------- */
.poem-card {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.poem-head {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
}

.poem-title {
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--orange-deep);
}

.poem-meta {
  color: var(--ink-light);
  font-size: 0.9rem;
}

.poem-text {
  font-size: 1.08rem;
  line-height: 2;
  font-weight: 700;
  color: #3d5872;
  background: #fffaf1;
  border-left: 4px solid var(--orange);
  border-radius: 0 12px 12px 0;
  padding: 8px 14px;
}

.poem-block {
  font-size: 0.95rem;
  background: #f6fbff;
  border-radius: var(--radius-sm);
  padding: 10px 14px;
}

.poem-block b {
  color: var(--blue-deep);
  margin-right: 6px;
}

.note-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 6px;
  font-size: 0.9rem;
}

.note-list li {
  background: #fff;
  border-radius: 10px;
  padding: 6px 10px;
}

.note-list .n-word {
  font-weight: 800;
  color: var(--orange-deep);
  margin-right: 6px;
}

/* ---------- 成语 ---------- */
.idiom-card {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.idiom-word {
  font-size: 1.35rem;
  font-weight: 900;
  color: var(--orange-deep);
  letter-spacing: 2px;
}

.idiom-pinyin {
  color: var(--ink-light);
  font-size: 0.9rem;
}

.idiom-mean {
  font-size: 0.95rem;
  background: #fff8ec;
  border-radius: var(--radius-sm);
  padding: 8px 12px;
}

.idiom-sentence {
  font-size: 0.9rem;
  color: #4a6b85;
  background: #f2f9ff;
  border-radius: var(--radius-sm);
  padding: 8px 12px;
}

.idiom-sentence b, .idiom-syn b {
  color: var(--blue-deep);
  margin-right: 6px;
}

/* ---------- 多音字 ---------- */
.poly-card {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.poly-char {
  font-size: 2rem;
  font-weight: 900;
  color: var(--blue-deep);
  background: var(--blue-bg);
  width: 64px;
  height: 64px;
  border-radius: 18px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.reading {
  background: #f7fcff;
  border-radius: var(--radius-sm);
  padding: 8px 12px;
  font-size: 0.95rem;
}

.reading .r-pinyin {
  font-weight: 800;
  color: var(--orange-deep);
  margin-right: 8px;
}

.reading .r-words {
  color: #48667f;
}

/* ---------- 近反义词 ---------- */
.group-card {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  font-size: 1.02rem;
  font-weight: 700;
}

.group-card .g-arrow {
  color: var(--orange-deep);
  font-size: 1.1rem;
}

.group-card .g-word {
  background: var(--green-bg);
  color: var(--green-deep);
  border-radius: 999px;
  padding: 5px 14px;
}

.group-card.g-anton .g-word {
  background: #ffeef1;
  color: #d85b78;
}

/* ---------- 英语单词 ---------- */
.word-card {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.word-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
}

.word-en {
  font-size: 1.25rem;
  font-weight: 900;
  color: var(--green-deep);
}

.speak-btn {
  border: none;
  background: linear-gradient(135deg, var(--green), var(--green-deep));
  color: #fff;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  font-size: 1.05rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 3px 8px rgba(62, 155, 69, 0.35);
  transition: transform 0.12s;
  flex-shrink: 0;
}

.speak-btn:active {
  transform: scale(0.85);
}

.speak-btn.small {
  width: 28px;
  height: 28px;
  font-size: 0.8rem;
  box-shadow: 0 2px 6px rgba(62, 155, 69, 0.3);
}

.word-phonetic {
  color: var(--ink-light);
  font-size: 0.85rem;
}

.word-zh {
  font-size: 0.95rem;
  font-weight: 700;
  color: #4a6b85;
}

.word-example {
  font-size: 0.85rem;
  color: #6d8aa5;
  background: #f2faf2;
  border-radius: 10px;
  padding: 6px 10px;
}

.word-example b {
  color: var(--green-deep);
}

/* ---------- 自然拼读 ---------- */
.phonics-card {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.phonics-head {
  display: flex;
  align-items: center;
  gap: 10px;
}

.phonics-sound {
  background: linear-gradient(135deg, var(--orange), var(--orange-deep));
  color: #fff;
  font-weight: 900;
  font-size: 1.15rem;
  padding: 5px 14px;
  border-radius: 12px;
  box-shadow: 0 3px 8px rgba(240, 136, 31, 0.35);
}

.phonics-phon {
  color: var(--ink-light);
  font-size: 0.9rem;
  font-weight: 700;
}

.word-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.word-chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--green-bg);
  color: var(--green-deep);
  border: none;
  border-radius: 999px;
  padding: 5px 12px;
  font-weight: 800;
  font-size: 0.95rem;
  transition: transform 0.12s, background 0.15s;
}

.word-chip:active {
  transform: scale(0.9);
  background: #d9f0d9;
}

/* ---------- 句型 ---------- */
.sentence-card {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.sentence-en {
  font-size: 1.1rem;
  font-weight: 800;
  color: var(--green-deep);
}

.sentence-zh {
  color: #4a6b85;
  font-size: 0.95rem;
}

.sentence-struct {
  font-size: 0.88rem;
  background: var(--blue-bg);
  color: var(--blue-deep);
  border-radius: 10px;
  padding: 6px 10px;
  font-weight: 700;
}

/* ---------- 空状态 / 高亮 ---------- */
.empty-state {
  text-align: center;
  padding: 40px 10px;
  color: var(--ink-light);
  font-size: 1rem;
}

.empty-state .e-emoji {
  font-size: 2.4rem;
  display: block;
  margin-bottom: 8px;
}

mark {
  background: var(--yellow);
  color: #7a5a12;
  border-radius: 6px;
  padding: 0 3px;
}

/* ---------- 响应式 ---------- */
@media (max-width: 520px) {
  .page {
    padding: 12px 12px 24px;
  }

  .hero-title {
    font-size: 1.65rem;
  }

  .home-cats {
    grid-template-columns: 1fr;
  }

  .module-grid {
    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
  }

  .topbar h1 {
    font-size: 1rem;
  }

  .bottom-nav a {
    padding: 4px 10px;
  }

  .times-table td,
  .times-table th {
    width: 40px;
    height: 40px;
  }

  .num-grid {
    grid-template-columns: repeat(auto-fill, minmax(52px, 1fr));
  }
}