/* 汉语入门 · 交互课程样式 */
:root{
  --paper:#fbf6ea; --paper-2:#f4ecd8; --ink:#2f2a22; --ink-soft:#6b5f4c;
  --line:#ddceb0; --accent:#9b2c2c; --accent-2:#b45309; --card:#fffdf7;
}
*{box-sizing:border-box}
body{
  margin:0; background:var(--paper); color:var(--ink);
  font-family:"Noto Serif SC","Songti SC","Source Han Serif SC",Georgia,serif;
  line-height:1.7; -webkit-text-size-adjust:100%;
}
.container{max-width:1000px;margin:0 auto;padding:24px 16px 80px}
h1{
  font-size:1.6rem;line-height:1.45;margin:8px 0 18px;padding-bottom:12px;
  border-bottom:3px double var(--line);color:var(--accent);
}
.intro-box{
  background:var(--paper-2);border-left:5px solid var(--accent-2);
  padding:12px 14px;border-radius:8px;margin-bottom:18px;font-size:.95rem;
}
.toc{background:var(--card);border:1px solid var(--line);border-radius:10px;padding:14px 16px;margin-bottom:22px}
.toc h3{margin:0 0 8px;font-size:1rem;color:var(--accent)}
.toc ul{margin:0;padding-left:20px}
.toc li{margin:4px 0}
.toc a{color:var(--ink);text-decoration:none;border-bottom:1px dotted var(--line)}
.toc a:hover{color:var(--accent)}
select{font:inherit;font-size:.85em;padding:2px 6px;border:1px solid var(--line);border-radius:6px;background:#fff;color:var(--ink)}

.root-header{
  display:flex;flex-wrap:wrap;align-items:center;gap:10px;cursor:pointer;
  background:linear-gradient(180deg,#fffdf7,#f4ecd8);
  border:1px solid var(--line);border-radius:10px;padding:12px 14px;margin:18px 0 0;
  scroll-margin-top:16px;
}
.root-header:hover{border-color:var(--accent-2)}
.root-num{font-size:.8rem;color:#fff;background:var(--accent);border-radius:999px;padding:2px 10px}
.root-title{font-size:1.15rem;font-weight:700}
.root-meaning{font-size:.85rem;color:var(--ink-soft)}
.collapse-icon{margin-left:auto;color:var(--ink-soft);transition:transform .2s}
.root-header.collapsed .collapse-icon{transform:rotate(-90deg)}
.root-section{
  border:1px solid var(--line);border-top:none;border-radius:0 0 10px 10px;
  background:var(--card);padding:14px;
}
.root-section.hidden{display:none}
.section-label{display:inline-block;font-size:.8rem;color:var(--ink-soft);margin:6px 0 8px}

.summary-table{width:100%;border-collapse:collapse;font-size:.92rem;margin-bottom:8px}
.summary-table th,.summary-table td{border:1px solid var(--line);padding:7px 9px;text-align:left;vertical-align:top}
.summary-table thead th{background:var(--paper-2)}
.summary-table tbody tr:nth-child(even){background:#fcf8ee}

.example-box{
  border:1px solid var(--line);border-left:4px solid var(--accent-2);
  border-radius:8px;background:#fffefa;padding:12px;margin:10px 0;
}
.ruby-line{display:flex;flex-wrap:wrap;align-items:flex-end;gap:2px 4px;margin-bottom:6px}
ruby-group{display:inline-flex;flex-direction:column-reverse;align-items:center;line-height:1.25}
ruby-group rb{display:block;font-size:1.9rem}
ruby-group rt{display:block;font-size:.85rem;color:var(--accent);letter-spacing:.02em}
.word-clickable{cursor:pointer;border-bottom:1px dashed transparent;border-radius:3px;padding:0 1px}
.word-clickable:hover,.word-clickable.active{background:#fdf0c8;border-bottom-color:var(--accent-2)}
.py-syllable{cursor:pointer}
.py-syllable:hover{color:var(--accent-2)}
.de-line{font-family:Georgia,serif;color:var(--ink);font-size:1.43rem;line-height:1.5;margin:4px 0 4px}
.en-line{font-family:Georgia,serif;color:var(--ink-soft);font-size:1.43rem;line-height:1.5;margin:0 0 8px;opacity:.95}
.fr-line,.es-line{font-family:Georgia,serif;color:var(--ink-soft);font-size:1.43rem;line-height:1.5;margin:0 0 8px;opacity:.95}
.en-audio-btn{font:inherit;font-size:.85rem;cursor:pointer;border:1px solid var(--line);background:#eef4fb;color:var(--ink);border-radius:999px;padding:4px 12px;margin-left:8px}
.en-audio-btn:hover{background:#dfeaf7}
.de-audio-btn{font:inherit;font-size:.85rem;cursor:pointer;border:1px solid var(--line);background:#f3eefb;color:var(--ink);border-radius:999px;padding:4px 12px;margin-left:8px}
.de-audio-btn:hover{background:#e6dcf5}
.audio-btn{
  font:inherit;font-size:.85rem;cursor:pointer;border:1px solid var(--line);
  background:var(--paper-2);color:var(--ink);border-radius:999px;padding:4px 12px;
}
.audio-btn:hover{background:#f0e2c2}
.speed-row{font-size:.8rem;color:var(--ink-soft);margin-left:8px}
.idiom-tag{
  display:block;background:#fdeaea;color:var(--accent);border:1px solid #f0c9c9;
  border-radius:6px;padding:6px 10px;font-size:1.2rem;line-height:1.6;margin:6px 0 0;
}
.idiom-line{display:flex;flex-wrap:wrap;align-items:center;gap:6px}
.idiom-en{display:block;color:var(--ink-soft);font-family:Georgia,serif}
.footer-tip{margin-top:26px;padding-top:12px;border-top:1px dashed var(--line);font-size:.85rem;color:var(--ink-soft)}

.tooltip{
  position:absolute;z-index:9999;display:none;max-width:280px;
  background:#2f2a22;color:#fdf6e6;border-radius:8px;padding:8px 10px;
  font-size:.85rem;line-height:1.5;box-shadow:0 8px 24px rgba(0,0,0,.25);
}
.tooltip.show{display:block}
.tt-word{font-size:1.05rem;font-weight:700;margin-bottom:2px}
.tt-meaning{color:#ffd9a0}
.tt-info{color:#cfc6b4;font-size:.8rem;margin-top:2px}

@media (max-width:640px){
  .container{padding:16px 12px 70px}
  h1{font-size:1.25rem}
  ruby-group rb{font-size:1.6rem}
  .summary-table{font-size:.85rem}
}

.detail-link{white-space:nowrap;color:var(--accent);text-decoration:none;font-size:.85rem;border-bottom:1px dotted var(--line)}
.detail-link:hover{color:var(--accent-2)}
.example-box{scroll-margin-top:16px}
.back-link{display:inline-block;margin-left:10px;font-size:.8rem;color:var(--ink-soft);text-decoration:none;border-bottom:1px dotted var(--line)}
.back-link:hover{color:var(--accent)}

.idiom-literal{margin-top:6px;padding-top:6px;border-top:1px dashed #f0c9c9;color:var(--ink-soft);font-size:1.05rem;line-height:1.6}
.idiom-literal-en{font-family:Georgia,serif}

/* 例句中的成语：不加框、不遮蔽拼音 */
.idiom-highlight,
.ruby-line .idiom-highlight,
span.word-clickable.idiom-highlight {
  background: none !important;
  background-image: none !important;
  border: 0 !important;
  box-shadow: none !important;
  padding: 0 !important;
  border-radius: 0 !important;
  color: #b45309 !important;
  font-weight: 700 !important;
}

/* ===== 移动端适配 ===== */
@media (max-width:640px){
  html,body{overflow-x:hidden !important}
  .container{max-width:100% !important;padding:14px 10px 70px !important}
  h1{font-size:1.2rem !important;line-height:1.5 !important}
  .intro-box{font-size:.9rem !important;padding:10px 12px !important}
  .toc ul{padding-left:16px !important}

  /* 概览表可横向滚动，避免撑破屏幕 */
  .summary-table{display:block !important;width:100% !important;overflow-x:auto !important;
    -webkit-overflow-scrolling:touch;white-space:nowrap;font-size:.85rem !important}
  .summary-table th,.summary-table td{padding:8px 8px !important;white-space:normal !important}
  .summary-table td:first-child,.summary-table th:first-child{min-width:5.5em}

  /* 例句区 */
  .example-box{padding:10px 10px !important;margin:10px 0 !important}
  .ruby-line{gap:2px 3px !important}
  ruby-group rb{font-size:1.45rem !important}
  ruby-group rt{font-size:.7rem !important}
  .de-line,.en-line,.fr-line,.es-line{font-size:1.02rem !important;line-height:1.55 !important;word-break:break-word}
  .idiom-tag{font-size:1rem !important;line-height:1.55 !important;padding:6px 8px !important}
  .idiom-literal{font-size:.92rem !important}
  .idiom-line{gap:4px !important}

  /* 按键触控目标 */
  .audio-btn,.en-audio-btn,.de-audio-btn,.rec-btn,button{min-height:36px;font-size:.85rem !important}
  .audio-btn,.en-audio-btn,.de-audio-btn{padding:6px 14px !important;margin:4px 6px 0 0 !important}
  .speed-row{display:block !important;margin:6px 0 0 !important}
  .detail-link,.back-link{display:inline-block;padding:4px 0;font-size:.85rem !important}

  /* 悬停提示改为贴合屏幕宽度 */
  .tooltip{max-width:calc(100vw - 24px) !important;font-size:.9rem !important}

  .root-header{padding:10px 12px !important;gap:6px !important}
  .root-title{font-size:1.02rem !important}
  .root-meaning{font-size:.8rem !important}
  .root-section{padding:10px !important}
  select{font-size:.8em !important}
}