/* =========================================================
   拾读 · 单词过关页（独立页面）
   复用 styles.css 的调色板与基础组件，这里只放这一页特有的布局
   ========================================================= */

.study-body {
  min-height: 100vh;
}

.study-main {
  width: 100%;
  max-width: 900px;
  margin: 0 auto;
  padding: clamp(20px, 3vw, 36px) 20px 72px;
}

/* ---------- 学习内容切换：学四级 / 背生词本 ---------- */

.study-modes {
  display: inline-flex;
  gap: 6px;
  margin: 0 0 16px;
  padding: 4px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: color-mix(in srgb, var(--paper) 82%, transparent);
}

.study-mode {
  display: inline-flex;
  align-items: baseline;
  gap: 6px;
  padding: 7px 16px;
  border: 0;
  border-radius: 999px;
  background: none;
  font-family: var(--font-ui);
  font-size: 13px;
  color: var(--ink-soft);
  cursor: pointer;
  transition: background-color .16s ease, color .16s ease;
}

.study-mode:hover { color: var(--ink); }

.study-mode.is-active {
  background: var(--green);
  color: var(--green-contrast);
}

.study-mode-count {
  font-size: 11px;
  font-variant-numeric: tabular-nums;
  opacity: .7;
}

.study-scope {
  margin: 0 0 12px;
  font-family: var(--font-ui);
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--ink-faint);
}

.study-scope strong {
  font-weight: 600;
  color: var(--ink-soft);
  font-variant-numeric: tabular-nums;
}

.study-layout {
  display: block;
}

.study-main-col {
  max-width: 820px;
  margin: 0 auto;
}

/* ---------- 页头说明 ---------- */

.study-kicker {
  margin: 0 0 10px;
  font-family: var(--font-ui);
  font-size: 11px;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--accent);
}

/* ---------- 今日统计 ---------- */

.study-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  margin-bottom: clamp(18px, 3vw, 26px);
  padding: 14px 10px;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: color-mix(in srgb, var(--paper) 80%, transparent);
}

.study-stat {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: center;
  gap: 2px 4px;
  text-align: center;
}

.study-stat-label {
  flex-basis: 100%;
  margin-bottom: 2px;
  font-family: var(--font-ui);
  font-size: 11.5px;
  color: var(--ink-faint);
}

.study-stat strong {
  font-family: var(--font-ui);
  font-size: 20px;
  font-weight: 600;
  color: var(--ink);
  font-variant-numeric: tabular-nums;
}

.study-stat-unit {
  font-family: var(--font-ui);
  font-size: 11.5px;
  color: var(--ink-faint);
}

/* ---------- 卡片 ---------- */

.study-card {
  position: relative;
  padding: clamp(22px, 4vw, 36px);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: var(--paper);
  box-shadow: var(--shadow-card);
}

.study-card-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  margin-bottom: clamp(16px, 2.6vw, 22px);
}

.study-pass-chip {
  padding: 4px 10px;
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  font-family: var(--font-ui);
  font-size: 11.5px;
  letter-spacing: .04em;
  color: var(--ink-faint);
}

.study-passes {
  display: flex;
  align-items: center;
  gap: 7px;
}

.study-pass-dot {
  width: 26px;
  height: 5px;
  border-radius: 999px;
  background: var(--line-strong);
  transition: background-color .2s ease, transform .2s ease;
}

.study-pass-dot.is-hit {
  background: var(--green);
}

.study-pass-dot.is-current {
  transform: scaleY(1.6);
  background: var(--gold);
}

.study-save {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 11px;
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  background: transparent;
  color: var(--ink-soft);
  font-family: var(--font-ui);
  font-size: 12px;
  cursor: pointer;
  transition: color .16s ease, border-color .16s ease, background-color .16s ease;
}

.study-save:hover {
  color: var(--green);
  border-color: var(--green);
}

.study-save.is-saved {
  color: var(--green);
  border-color: color-mix(in srgb, var(--green) 45%, transparent);
  background: var(--sage);
}

.study-word {
  margin: 0;
  font-family: var(--font-en);
  font-size: clamp(38px, 7vw, 62px);
  font-weight: 600;
  line-height: 1.08;
  letter-spacing: -.01em;
  color: var(--ink);
  overflow-wrap: anywhere;
}

.study-word-meta {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 10px;
  font-family: var(--font-ui);
  font-size: 14px;
  color: var(--ink-faint);
}

.study-phonetic {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .02em;
}

.study-speak {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 30px;
  height: 30px;
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  background: transparent;
  color: var(--ink-soft);
  cursor: pointer;
  transition: color .16s ease, border-color .16s ease;
}

.study-speak:hover {
  color: var(--green);
  border-color: var(--green);
}

.study-pos {
  padding: 2px 7px;
  border-radius: 5px;
  background: var(--sage);
  color: var(--ink-soft);
  font-size: 11px;
  letter-spacing: .04em;
}

/* ---------- 回想区（未展开时是「点击空白处」） ---------- */

.study-blank {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: clamp(150px, 22vw, 220px);
  margin-top: clamp(18px, 3vw, 26px);
  border: 1px dashed var(--line-strong);
  border-radius: var(--radius-md);
  background: color-mix(in srgb, var(--bg) 55%, transparent);
  cursor: pointer;
  transition: border-color .16s ease, background-color .16s ease;
}

.study-blank:hover {
  border-color: color-mix(in srgb, var(--green) 45%, var(--line-strong));
  background: color-mix(in srgb, var(--sage) 40%, transparent);
}

.study-blank[hidden] {
  display: none;
}

.study-hint {
  margin: 0;
  font-family: var(--font-ui);
  font-size: 13.5px;
  line-height: 2;
  color: var(--ink-faint);
  text-align: center;
  pointer-events: none;
}

.study-hint span {
  font-size: 12px;
  opacity: .72;
}

/* ---------- 释义区 ---------- */

.study-reveal {
  margin-top: clamp(18px, 3vw, 24px);
  padding-top: clamp(16px, 2.6vw, 22px);
  border-top: 1px dashed var(--line-strong);
}

.study-def-zh {
  margin: 0;
  font-family: var(--font-zh-serif);
  font-size: clamp(19px, 2.6vw, 23px);
  line-height: 1.7;
  color: var(--ink);
}

.study-def-en {
  margin: 8px 0 0;
  font-family: var(--font-en);
  font-size: clamp(15px, 2vw, 17px);
  line-height: 1.65;
  color: var(--ink-soft);
}

.study-block {
  margin-top: clamp(18px, 3vw, 26px);
}

.study-block-title {
  margin: 0 0 10px;
  font-family: var(--font-ui);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--ink-faint);
}

.study-block-hint {
  margin-left: 6px;
  font-weight: 400;
  letter-spacing: .04em;
  text-transform: none;
  color: var(--ink-faint);
  opacity: .75;
}

/* .root-chips / .root-chip / .root-empty 的样式在 styles.css 里，两个页面共用 */

.example-list {
  display: grid;
  gap: 10px;
}

.example-item {
  padding: 11px 14px;
  border-left: 2px solid var(--line-strong);
  background: linear-gradient(90deg, color-mix(in srgb, var(--sage) 55%, transparent), transparent 70%);
}

.example-en {
  margin: 0;
  font-family: var(--font-en);
  font-size: 15.5px;
  line-height: 1.6;
  color: var(--ink);
}

.example-zh {
  margin: 4px 0 0;
  font-family: var(--font-zh-serif);
  font-size: 13px;
  line-height: 1.6;
  color: var(--ink-faint);
  max-height: 0;
  overflow: hidden;
  opacity: 0;
  transition: max-height .2s ease, opacity .2s ease, margin-top .2s ease;
}

.example-item.is-open .example-zh {
  max-height: 6em;
  opacity: 1;
}

.example-toggle {
  margin-top: 6px;
  padding: 0;
  border: 0;
  background: none;
  color: var(--ink-faint);
  font-family: var(--font-ui);
  font-size: 11.5px;
  text-decoration: underline;
  text-underline-offset: 3px;
  cursor: pointer;
}

.example-toggle:hover {
  color: var(--green);
}

/* ---------- 操作区 ---------- */

.study-actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin-top: clamp(22px, 3.4vw, 32px);
}

.study-card-foot {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  margin-top: 16px;
  padding-top: 14px;
  border-top: 1px solid var(--line);
}

.study-group-note {
  font-family: var(--font-ui);
  font-size: 12px;
  color: var(--ink-faint);
  font-variant-numeric: tabular-nums;
}

.study-group-note strong {
  color: var(--ink-soft);
}

.study-judge {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

.study-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  width: 100%;
  min-height: 54px;
  padding: 12px 18px;
  border: 1px solid transparent;
  border-radius: 14px;
  font-family: var(--font-ui);
  font-size: 15.5px;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  transition: transform .14s ease, background-color .16s ease, border-color .16s ease, color .16s ease;
}

.study-btn:active {
  transform: translateY(1px);
}

.study-btn kbd {
  padding: 1px 5px;
  border: 1px solid currentColor;
  border-radius: 4px;
  font-family: var(--font-ui);
  font-size: 11px;
  font-weight: 600;
  opacity: .78;
}

.study-btn--reveal {
  background: transparent;
  border-color: var(--line-strong);
  color: var(--ink-soft);
}

.study-btn--reveal:hover {
  color: var(--green);
  border-color: var(--green);
}

.study-btn--known {
  background: var(--green);
  color: var(--green-contrast);
}

.study-btn--known:hover {
  background: var(--green-deep);
}

.study-btn--unknown {
  background: transparent;
  border-color: var(--line-strong);
  color: var(--warn-ink, var(--accent-deep));
}

.study-btn--unknown:hover {
  border-color: var(--accent);
  background: color-mix(in srgb, var(--accent-soft) 70%, transparent);
}

/* ---------- 页脚提示 ---------- */

.study-footnote {
  margin: 16px 0 0;
  font-family: var(--font-ui);
  font-size: 12px;
  line-height: 1.7;
  color: var(--ink-faint);
  text-align: center;
}

/* ---------- 完成态 ---------- */

.study-finish {
  padding: clamp(28px, 4vw, 44px);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: var(--paper);
  box-shadow: var(--shadow-card);
  text-align: center;
}

.study-finish-title {
  margin: 0;
  font-family: var(--font-zh-serif);
  font-size: clamp(24px, 3.4vw, 30px);
  font-weight: 600;
  color: var(--ink);
}

.study-finish-desc {
  margin: 12px 0 0;
  font-family: var(--font-ui);
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--ink-soft);
}

.study-finish-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px;
  margin-top: 26px;
}

.study-finish-actions .study-btn {
  width: auto;
  min-width: 150px;
}

.study-empty {
  padding: 34px 24px;
  border: 1px dashed var(--line-strong);
  border-radius: var(--radius-lg);
  font-family: var(--font-ui);
  font-size: 14px;
  line-height: 1.8;
  color: var(--ink-soft);
  text-align: center;
}

/* ---------- 站点页脚与提示 ---------- */

.study-site-footer {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 8px 24px;
  width: 100%;
  max-width: 860px;
  margin: 0 auto;
  padding: 0 20px 40px;
  font-family: var(--font-ui);
  font-size: 11.5px;
  color: var(--ink-faint);
}

.study-toast {
  position: fixed;
  left: 50%;
  bottom: 28px;
  z-index: 80;
  transform: translateX(-50%);
  max-width: min(88vw, 420px);
  padding: 11px 18px;
  border-radius: 999px;
  background: var(--paper-raised);
  border: 1px solid var(--line-strong);
  box-shadow: var(--shadow-pop);
  color: var(--ink);
  font-family: var(--font-ui);
  font-size: 13px;
  text-align: center;
}

.study-toast[hidden] {
  display: none;
}

/* ---------- 手机 ---------- */

.study-actions .study-btn {
  min-height: 62px;
  font-size: 16.5px;
  letter-spacing: .04em;
}

@media (max-width: 640px) {
  .study-main {
    padding: 22px 16px 48px;
  }

  .study-stats {
    gap: 6px;
    padding: 10px 4px;
  }

  .study-stat strong {
    font-size: 18px;
  }

  .study-card {
    padding: 18px 16px;
  }

  .study-actions {
    gap: 10px;
  }

  .study-actions .study-btn {
    min-height: 56px;
    font-size: 16px;
  }

  .study-blank {
    min-height: 132px;
  }

  .study-finish-actions .study-btn {
    width: 100%;
  }

  .study-site-footer {
    padding: 0 16px 32px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .study-pass-dot,
  .study-track span,
  .example-zh,
  .study-btn {
    transition: none;
  }
}


/* 生词本模式下，「加入生词本」变成「熟悉 · 移出」 */
.study-save.is-forget {
  border-color: color-mix(in srgb, var(--accent) 55%, transparent);
  color: var(--accent-deep);
}

.study-save.is-forget:hover {
  border-color: var(--accent);
  background: color-mix(in srgb, var(--accent-soft) 70%, transparent);
}