/* ==========================================================================
   单词小乐园 · style.css
   童趣、响应式的小学生英语单词练习应用主题
   ========================================================================== */

:root {
  /* 主色板：明亮、活泼、适合儿童 */
  --c-bg: #fff7ed;
  --c-bg-grad-1: #ffe4e6;
  --c-bg-grad-2: #e0f2fe;
  --c-surface: #ffffff;
  --c-surface-soft: #fff1f2;
  --c-text: #3f3a36;
  --c-text-soft: #7c7469;
  --c-primary: #ff8a5b;
  --c-primary-dark: #f0663a;
  --c-accent: #4dabf7;
  --c-accent-dark: #2f8fe0;
  --c-green: #51cf66;
  --c-green-dark: #37b24d;
  --c-red: #ff6b6b;
  --c-red-dark: #f03e3e;
  --c-yellow: #ffd43b;
  --c-purple: #b197fc;

  --radius-sm: 10px;
  --radius: 18px;
  --radius-lg: 26px;
  --shadow-sm: 0 2px 6px rgba(0, 0, 0, .06);
  --shadow: 0 8px 22px rgba(0, 0, 0, .08);
  --shadow-lg: 0 14px 34px rgba(0, 0, 0, .12);
  --ring: 0 0 0 4px rgba(255, 138, 91, .25);

  --font: "PingFang SC", "Microsoft YaHei", "Segoe UI", "Comic Sans MS",
    system-ui, -apple-system, sans-serif;
}

* { box-sizing: border-box; }

html, body { margin: 0; padding: 0; }

body {
  font-family: var(--font);
  color: var(--c-text);
  background: linear-gradient(160deg, var(--c-bg-grad-1) 0%, var(--c-bg) 45%, var(--c-bg-grad-2) 100%);
  background-attachment: fixed;
  min-height: 100vh;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3 { margin: 0 0 .4em; font-weight: 800; }
h2 { font-size: 1.15rem; }
p { margin: 0; }
button { font-family: inherit; cursor: pointer; }
input, select { font-family: inherit; }

/* ============ 顶部 Header ============ */
.app-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, .85);
  backdrop-filter: blur(10px);
  box-shadow: var(--shadow-sm);
  padding: 12px clamp(12px, 4vw, 32px) 0;
}

.brand {
  display: flex;
  align-items: center;
  gap: 14px;
  max-width: 1000px;
  margin: 0 auto;
}

.mascot {
  font-size: 2.6rem;
  line-height: 1;
  filter: drop-shadow(0 4px 6px rgba(0, 0, 0, .15));
  animation: bob 3s ease-in-out infinite;
}
@keyframes bob {
  0%, 100% { transform: translateY(0) rotate(-3deg); }
  50% { transform: translateY(-6px) rotate(3deg); }
}

.brand-text h1 {
  font-size: clamp(1.3rem, 4vw, 1.7rem);
  margin: 0;
  background: linear-gradient(90deg, var(--c-primary), var(--c-accent));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}
.subtitle { color: var(--c-text-soft); font-size: .8rem; }

.hud {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}
.hud-item {
  background: var(--c-surface-soft);
  border-radius: 999px;
  padding: 6px 12px;
  font-size: .95rem;
  font-weight: 700;
  box-shadow: var(--shadow-sm);
  white-space: nowrap;
}
.accent-toggle {
  border: 2px solid var(--c-accent);
  background: #fff;
  color: var(--c-accent-dark);
  border-radius: 999px;
  padding: 6px 12px;
  font-weight: 700;
  font-size: .85rem;
  transition: transform .1s, background .2s;
}
.accent-toggle:hover { background: var(--c-accent); color: #fff; }
.accent-toggle:active { transform: scale(.95); }

/* ============ 标签页 ============ */
.tabs {
  display: flex;
  gap: 6px;
  max-width: 1000px;
  margin: 12px auto 0;
  overflow-x: auto;
  padding-bottom: 8px;
  scrollbar-width: none;
}
.tabs::-webkit-scrollbar { display: none; }
.tab {
  border: none;
  background: transparent;
  color: var(--c-text-soft);
  font-size: .95rem;
  font-weight: 700;
  padding: 8px 14px;
  border-radius: 999px 999px 0 0;
  white-space: nowrap;
  transition: all .18s;
  border-bottom: 3px solid transparent;
}
.tab:hover { color: var(--c-primary-dark); background: var(--c-surface-soft); }
.tab[aria-current="true"] {
  color: var(--c-primary-dark);
  background: var(--c-surface);
  border-bottom-color: var(--c-primary);
  box-shadow: var(--shadow-sm);
}

/* ============ 容器与卡片 ============ */
.container {
  max-width: 1000px;
  margin: 0 auto;
  padding: 20px clamp(12px, 4vw, 32px) 60px;
}

.view { animation: fadeIn .3s ease; }
.view.hidden { display: none; }
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

.card {
  background: var(--c-surface);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: clamp(16px, 3vw, 24px);
  margin-bottom: 20px;
}

/* ============ 表单 ============ */
.word-form {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}
.field { display: flex; flex-direction: column; gap: 5px; }
.field-wide { grid-column: 1 / -1; }
.field label { font-size: .82rem; font-weight: 700; color: var(--c-text-soft); }

input[type="text"], select {
  width: 100%;
  border: 2px solid #f0e6db;
  border-radius: var(--radius-sm);
  padding: 10px 12px;
  font-size: 1rem;
  background: #fffdfb;
  transition: border-color .18s, box-shadow .18s;
}
input[type="text"]:focus, select:focus {
  outline: none;
  border-color: var(--c-primary);
  box-shadow: var(--ring);
}

.input-with-btn { display: flex; gap: 8px; }
.input-with-btn input { flex: 1; }

.word-form .btn-primary { grid-column: 1 / -1; }

/* ============ 按钮 ============ */
.btn {
  border: none;
  border-radius: var(--radius-sm);
  padding: 10px 16px;
  font-size: .95rem;
  font-weight: 700;
  transition: transform .1s, box-shadow .18s, background .2s, opacity .2s;
  white-space: nowrap;
}
.btn:active { transform: scale(.96); }
.btn:disabled { opacity: .5; cursor: not-allowed; }

.btn-primary {
  background: linear-gradient(90deg, var(--c-primary), var(--c-primary-dark));
  color: #fff;
  box-shadow: 0 6px 14px rgba(240, 102, 58, .35);
}
.btn-primary:hover { box-shadow: 0 8px 20px rgba(240, 102, 58, .45); }

.btn-ghost {
  background: var(--c-surface-soft);
  color: var(--c-primary-dark);
  box-shadow: var(--shadow-sm);
}
.btn-ghost:hover { background: #ffe3d6; }
.btn-ghost.danger { color: var(--c-red-dark); background: #fff0f0; }
.btn-ghost.danger:hover { background: #ffe0e0; }

.btn-round {
  background: #fff;
  color: var(--c-text);
  border-radius: 999px;
  box-shadow: var(--shadow);
  padding: 10px 18px;
}
.btn-round:hover { box-shadow: var(--shadow-lg); }
.btn-round.good { background: var(--c-green); color: #fff; }
.btn-round.bad { background: var(--c-red); color: #fff; }

/* ============ 统计 / 成就 ============ */
.stats-card .stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
  gap: 12px;
}
.stat-tile {
  background: var(--c-surface-soft);
  border-radius: var(--radius-sm);
  padding: 12px;
  text-align: center;
}
.stat-tile .num { font-size: 1.5rem; font-weight: 800; color: var(--c-primary-dark); }
.stat-tile .lbl { font-size: .78rem; color: var(--c-text-soft); }
.achv {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  background: linear-gradient(90deg, #fff3bf, #ffe066);
  border-radius: 999px;
  padding: 4px 10px;
  font-size: .82rem;
  font-weight: 700;
  margin: 3px;
}
.achv.locked { background: #eee; color: #aaa; filter: grayscale(1); }

/* ============ 单词列表 ============ */
.list-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 12px;
}
.badge {
  display: inline-block;
  background: var(--c-accent);
  color: #fff;
  border-radius: 999px;
  font-size: .8rem;
  padding: 1px 9px;
  vertical-align: middle;
}
.list-actions { display: flex; gap: 6px; flex-wrap: wrap; }
.list-actions .btn { padding: 7px 12px; font-size: .85rem; }

.filter-row { display: flex; gap: 10px; margin-bottom: 14px; }
.filter-row input { flex: 2; }
.filter-row select { flex: 1; min-width: 120px; }

.word-list { list-style: none; margin: 0; padding: 0; display: grid; gap: 10px; }
.word-item {
  display: flex;
  align-items: center;
  gap: 12px;
  background: var(--c-surface-soft);
  border-radius: var(--radius-sm);
  padding: 12px 14px;
  transition: transform .12s, box-shadow .18s;
}
.word-item:hover { transform: translateX(3px); box-shadow: var(--shadow-sm); }
.word-item .wi-main { flex: 1; min-width: 0; }
.word-item .wi-en { font-size: 1.1rem; font-weight: 800; }
.word-item .wi-phon { font-size: .82rem; color: var(--c-accent-dark); margin-left: 6px; font-weight: 500; }
.word-item .wi-zh { color: var(--c-text-soft); font-size: .92rem; }
.word-item .wi-ex { font-size: .8rem; color: #a89f92; font-style: italic; margin-top: 2px; }
.word-item .wi-cat {
  font-size: .72rem;
  background: var(--c-purple);
  color: #fff;
  border-radius: 999px;
  padding: 1px 8px;
  align-self: flex-start;
}
.word-item .wi-btn {
  border: none;
  background: #fff;
  border-radius: 50%;
  width: 34px;
  height: 34px;
  font-size: 1rem;
  box-shadow: var(--shadow-sm);
  display: grid;
  place-items: center;
}
.word-item .wi-btn:hover { background: #ffecec; }
.wi-tag {
  font-size: .68rem;
  padding: 1px 7px;
  border-radius: 999px;
  font-weight: 700;
}
.wi-tag.wrong { background: #ffe3e3; color: var(--c-red-dark); }
.wi-tag.mastered { background: #d3f9d8; color: var(--c-green-dark); }

.empty-hint {
  text-align: center;
  color: var(--c-text-soft);
  padding: 30px 10px;
  font-size: .95rem;
}

/* ============ 模式横幅 ============ */
.mode-banner {
  border-radius: var(--radius);
  padding: 18px 22px;
  margin-bottom: 20px;
  color: #fff;
  box-shadow: var(--shadow);
}
.mode-banner h2 { color: #fff; }
.mode-banner p { opacity: .95; font-size: .9rem; }
.learn-bg { background: linear-gradient(120deg, #4dabf7, #3b5bdb); }
.spell-bg { background: linear-gradient(120deg, #ff922b, #f76707); }
.review-bg { background: linear-gradient(120deg, #9775fa, #7048e8); }
.exam-bg { background: linear-gradient(120deg, #20c997, #0ca678); }
.game-bg { background: linear-gradient(120deg, #ff6b9d, #f06595); }
.mistakes-bg { background: linear-gradient(120deg, #e8590c, #d9480f); }

/* ============ 错题本 ============ */
.mistake-list { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 12px; }
.mistake-item {
  background: var(--c-surface-soft);
  border: 1px solid #ffe3cf;
  border-radius: var(--radius);
  padding: 14px 16px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.mistake-item.resolved { opacity: .62; background: #f3fbf4; border-color: #d3f9d8; }
.mi-top { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; }
.mi-prompt { font-size: 1.15rem; font-weight: 700; color: var(--c-text); }
.mi-answers { display: flex; flex-direction: column; gap: 4px; font-size: .95rem; }
.mi-answer { color: var(--c-red-dark); }
.mi-answer b { color: var(--c-red-dark); }
.mi-correct { color: var(--c-green-dark); }
.mi-correct b { color: var(--c-green-dark); }
.mi-meta { display: flex; align-items: center; gap: 8px; font-size: .8rem; color: var(--c-text-soft); }
.mi-badge {
  display: inline-block; padding: 2px 9px; border-radius: 999px;
  font-size: .75rem; font-weight: 700; color: #fff;
}
.mi-badge.spell { background: #f76707; }
.mi-badge.exam { background: #0ca678; }
.mi-badge.review { background: #7048e8; }
.mi-badge.game { background: #f06595; }
.mi-actions { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 2px; }
.mi-actions .btn { font-size: .85rem; padding: 6px 12px; }
.mi-removed-note { font-size: .8rem; color: var(--c-text-soft); font-style: italic; }
.exam-tomistakes { text-align: center; margin-top: 14px; }

/* ============ 设置行 ============ */
.setting-row {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 14px;
}
.setting-row label { min-width: 90px; font-weight: 700; color: var(--c-text-soft); font-size: .9rem; }
.setting-row select { max-width: 260px; }

/* ============ 云端同步面板 ============ */
.sync-card { border: 2px solid #e3f0ff; }
.sync-card h2 { color: var(--c-accent-dark); }
.sync-desc { color: var(--c-text-soft); font-size: .88rem; margin-bottom: 14px; }
.sync-card .setting-row label { min-width: 96px; }
.sync-card input[type="password"] {
  flex: 1;
  border: 2px solid #f0e6db;
  border-radius: var(--radius-sm);
  padding: 10px 12px;
  font-size: 1rem;
  background: #fffdfb;
}
.sync-card input[type="password"]:focus { outline: none; border-color: var(--c-accent); box-shadow: var(--ring); }
.sync-toggle-row { align-items: center; }
.sync-toggle-row input[type="checkbox"] { width: 20px; height: 20px; accent-color: var(--c-accent); }
.sync-actions { display: flex; align-items: center; gap: 14px; flex-wrap: wrap; margin-top: 4px; }
.sync-status { font-size: .85rem; color: var(--c-text-soft); font-weight: 600; }
.sync-status.ok { color: var(--c-green-dark); }
.sync-status.err { color: var(--c-red-dark); }

/* ============ 学习闪卡 ============ */
.flashcard-wrap {
  display: grid;
  place-items: center;
  min-height: 260px;
  perspective: 1200px;
  margin-bottom: 18px;
}
.flashcard {
  width: min(420px, 92%);
  height: 240px;
  position: relative;
  transform-style: preserve-3d;
  transition: transform .5s;
  cursor: pointer;
}
.flashcard.flipped { transform: rotateY(180deg); }
.flashcard .face {
  position: absolute;
  inset: 0;
  border-radius: var(--radius-lg);
  backface-visibility: hidden;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 20px;
  box-shadow: var(--shadow-lg);
  text-align: center;
}
.flashcard .front { background: linear-gradient(150deg, #fff, #e7f5ff); }
.flashcard .back { background: linear-gradient(150deg, #fff, #fff0f6); transform: rotateY(180deg); }
.flashcard .fc-en { font-size: 2.4rem; font-weight: 800; color: var(--c-accent-dark); }
.flashcard .fc-phon { font-size: 1rem; color: var(--c-text-soft); }
.flashcard .fc-zh { font-size: 1.9rem; font-weight: 800; color: var(--c-primary-dark); }
.flashcard .fc-ex { font-size: .9rem; color: var(--c-text-soft); font-style: italic; }
.flashcard .fc-hint { font-size: .75rem; color: #b0a89c; }

.learn-controls, .review-controls {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  justify-content: center;
  margin-bottom: 16px;
}

/* ============ 进度条 ============ */
.progress-line {
  height: 12px;
  background: #ffe8dc;
  border-radius: 999px;
  overflow: hidden;
  margin: 8px auto;
  max-width: 500px;
}
.progress-bar {
  height: 100%;
  width: 0;
  background: linear-gradient(90deg, var(--c-primary), var(--c-yellow));
  border-radius: 999px;
  transition: width .3s ease;
}

/* ============ 拼写 ============ */
.spell-question { text-align: center; }
.spell-question .sq-prompt { font-size: 1.8rem; font-weight: 800; margin-bottom: 6px; }
.spell-question .sq-sub { color: var(--c-text-soft); margin-bottom: 16px; }
.spell-input-row { display: flex; gap: 10px; justify-content: center; flex-wrap: wrap; margin-bottom: 12px; }
.spell-input-row input { max-width: 320px; text-align: center; font-size: 1.3rem; letter-spacing: 2px; }
.spell-feedback { text-align: center; min-height: 28px; font-weight: 700; font-size: 1.05rem; }
.spell-feedback.ok { color: var(--c-green-dark); }
.spell-feedback.no { color: var(--c-red-dark); }
.spell-hint-txt { text-align: center; letter-spacing: 6px; font-size: 1.5rem; color: var(--c-accent-dark); font-weight: 800; min-height: 28px; }
.spell-actions { display: flex; gap: 10px; justify-content: center; flex-wrap: wrap; margin-top: 14px; }

/* ============ 复习 ============ */
.review-wrap { text-align: center; margin-bottom: 16px; }
.review-card {
  background: linear-gradient(150deg, #fff, #f3f0ff);
  border-radius: var(--radius-lg);
  padding: 30px 20px;
  box-shadow: var(--shadow);
  max-width: 460px;
  margin: 0 auto;
}
.review-card .rc-zh { font-size: 2rem; font-weight: 800; color: var(--c-purple); }
.review-card .rc-answer { margin-top: 14px; }
.review-card .rc-en { font-size: 1.8rem; font-weight: 800; color: var(--c-accent-dark); }
.review-card .rc-phon { color: var(--c-text-soft); }
.review-card .rc-ex { font-size: .9rem; color: var(--c-text-soft); font-style: italic; margin-top: 6px; }

/* ============ 考试 ============ */
.exam-area .exam-progress { text-align: center; font-weight: 700; color: var(--c-text-soft); margin-bottom: 10px; }
.exam-q-card {
  background: var(--c-surface);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 22px;
}
.exam-q-title { font-size: 1.5rem; font-weight: 800; text-align: center; margin-bottom: 18px; }
.exam-options { display: grid; gap: 10px; }
.exam-option {
  border: 2px solid #f0e6db;
  background: #fffdfb;
  border-radius: var(--radius-sm);
  padding: 12px 16px;
  font-size: 1.05rem;
  font-weight: 600;
  text-align: left;
  transition: all .15s;
}
.exam-option:hover:not(:disabled) { border-color: var(--c-accent); background: #eef7ff; }
.exam-option.correct { border-color: var(--c-green); background: #ebfbee; color: var(--c-green-dark); }
.exam-option.wrong { border-color: var(--c-red); background: #fff0f0; color: var(--c-red-dark); }
.exam-result { text-align: center; }
.exam-result .er-score { font-size: 3rem; font-weight: 800; color: var(--c-primary-dark); }
.exam-result .er-msg { font-size: 1.1rem; margin: 8px 0 18px; }
.exam-review-item { text-align: left; padding: 8px 0; border-bottom: 1px dashed #eee; font-size: .92rem; }
.exam-review-item.ok::before { content: "✅ "; }
.exam-review-item.no::before { content: "❌ "; }

/* ============ 配对游戏 ============ */
.game-board {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
  gap: 12px;
  margin-bottom: 20px;
}
.game-cell {
  min-height: 78px;
  border-radius: var(--radius-sm);
  border: 2px solid transparent;
  background: linear-gradient(150deg, #fff, #e7f5ff);
  box-shadow: var(--shadow-sm);
  display: grid;
  place-items: center;
  text-align: center;
  padding: 8px;
  font-size: 1.05rem;
  font-weight: 700;
  transition: transform .12s, box-shadow .18s, opacity .3s;
}
.game-cell:hover { transform: translateY(-3px); box-shadow: var(--shadow); }
.game-cell.zh { background: linear-gradient(150deg, #fff, #fff0f6); }
.game-cell.selected { border-color: var(--c-primary); box-shadow: var(--ring); }
.game-cell.matched { opacity: 0; pointer-events: none; transform: scale(.6); }
.game-cell.shake { animation: shake .4s; }
@keyframes shake {
  0%, 100% { transform: translateX(0); }
  25% { transform: translateX(-6px); }
  75% { transform: translateX(6px); }
}
.game-result { text-align: center; }
.game-result .gr-emoji { font-size: 3rem; }

/* ============ Toast ============ */
.toast {
  position: fixed;
  left: 50%;
  bottom: 32px;
  transform: translateX(-50%) translateY(20px);
  background: rgba(63, 58, 54, .95);
  color: #fff;
  padding: 12px 22px;
  border-radius: 999px;
  font-weight: 700;
  box-shadow: var(--shadow-lg);
  z-index: 999;
  opacity: 0;
  transition: opacity .25s, transform .25s;
  max-width: 90vw;
  text-align: center;
}
.toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }
.toast.ok { background: rgba(55, 178, 77, .96); }
.toast.err { background: rgba(240, 62, 62, .96); }

/* ============ Footer ============ */
.app-footer {
  text-align: center;
  color: var(--c-text-soft);
  font-size: .82rem;
  padding: 20px 16px 30px;
}

/* ============ 响应式 ============ */
@media (max-width: 640px) {
  .word-form { grid-template-columns: 1fr; }
  .brand { flex-wrap: wrap; }
  .hud { width: 100%; margin-left: 0; justify-content: flex-start; }
  .filter-row { flex-direction: column; }
  .setting-row { flex-direction: column; align-items: stretch; }
  .setting-row label { min-width: 0; }
  .setting-row select { max-width: none; }
  .flashcard { height: 210px; }
  .flashcard .fc-en { font-size: 2rem; }
  .flashcard .fc-zh { font-size: 1.6rem; }
}

@media (prefers-reduced-motion: reduce) {
  * { animation-duration: .001s !important; transition-duration: .001s !important; }
}