/* Oak House 3ESO 学习资料 — 书架主题 */
:root{
  --paper:#FAF8F3; --card:#FFFFFF; --ink:#1C2433; --muted:#687385;
  --line:#E9E1D3; --accent:#1D4ED8; --accent-soft:#E8EEFB;
}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--paper);color:var(--ink);
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Hiragino Sans GB","Microsoft YaHei","微软雅黑",sans-serif;
  line-height:1.8}
.serif, .hero h1, .logo, .card h3, article h1{font-family:Georgia,"Songti SC","STSong","Noto Serif SC","SimSun",serif}
.wrap{max-width:980px;margin:0 auto;padding:0 20px}
/* 顶栏 */
header.site{background:rgba(255,255,255,.92);backdrop-filter:blur(8px);border-bottom:1px solid var(--line);position:sticky;top:0;z-index:10}
header.site .wrap{display:flex;align-items:center;gap:14px;padding:12px 20px;flex-wrap:wrap}
.logo{font-weight:700;font-size:19px;color:var(--ink);text-decoration:none;white-space:nowrap;letter-spacing:.02em}
.logo em{font-style:normal;color:var(--accent)}
.searchbox{margin-left:auto;position:relative;flex:1;min-width:200px;max-width:360px}
.searchbox input{width:100%;padding:9px 14px;border:1px solid var(--line);border-radius:999px;font-size:14px;font-family:inherit;background:#fff;color:var(--ink)}
.searchbox input:focus{outline:2px solid var(--accent);outline-offset:1px;border-color:var(--accent)}
.results{position:absolute;top:112%;left:0;right:0;background:#fff;border:1px solid var(--line);border-radius:12px;box-shadow:0 12px 32px rgba(28,36,51,.12);max-height:340px;overflow:auto;display:none;z-index:20}
.results a{display:block;padding:9px 14px;text-decoration:none;color:var(--ink);border-bottom:1px solid var(--line);font-size:14px}
.results a:hover{background:var(--accent-soft)}
.results a:last-child{border-bottom:none}
/* 首页 hero */
.hero{padding:56px 0 10px;max-width:640px}
.eyebrow{margin:0 0 10px;font-size:14px;color:var(--muted);letter-spacing:.04em}
.hero h1{font-size:40px;line-height:1.3;margin:0 0 12px;font-weight:700}
.hero p{color:var(--muted);margin:0;font-size:15px}
/* 书架 */
.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(270px,1fr));gap:18px;padding:30px 0 56px}
.card{background:var(--card);border:1px solid var(--line);border-radius:14px;padding:20px 20px 18px;text-decoration:none;color:var(--ink);position:relative;display:block;overflow:hidden;transition:transform .18s ease,box-shadow .18s ease}
.card::before{content:"";position:absolute;top:0;left:0;right:0;height:5px;background:var(--accent)}
.card:hover{transform:translateY(-3px);box-shadow:0 14px 30px rgba(28,36,51,.10)}
.card h3{margin:2px 0 6px;font-size:20px;padding-right:64px}
.card .sub{font-size:13px;color:var(--accent);margin:0 0 8px;font-weight:600}
.card .desc{font-size:13px;color:var(--muted);margin:0;line-height:1.7}
.badge{position:absolute;top:16px;right:14px;font-size:11px;background:var(--accent-soft);color:var(--accent);border-radius:999px;padding:3px 10px;white-space:nowrap;font-weight:600}
/* 文章页 */
article{background:var(--card);border:1px solid var(--line);border-radius:16px;padding:36px 40px;margin:28px 0}
.kicker{display:flex;align-items:center;gap:8px;font-size:13px;color:var(--muted);margin:0 0 6px}
.kdot{width:10px;height:10px;border-radius:50%;background:var(--accent);flex:none}
article h1{font-size:29px;line-height:1.4;margin:0 0 8px}
article h2{font-size:20px;margin:40px 0 12px;padding-left:14px;border-left:4px solid var(--accent);line-height:1.5}
article h3{font-size:16px;margin:26px 0 8px}
article p{margin:10px 0}
article ul{margin:10px 0;padding-left:22px}
article li{margin:6px 0}
table{width:100%;border-collapse:collapse;font-size:14px;margin:4px 0}
th,td{border:1px solid var(--line);padding:9px 12px;text-align:left;vertical-align:top}
thead th{background:var(--accent-soft);color:var(--ink);font-weight:700}
tbody tr:nth-child(even){background:#FDFCF9}
.twrap{overflow-x:auto;margin:14px -4px;padding:0 4px}
.pagenav{display:flex;justify-content:space-between;gap:12px;margin:0 0 40px;flex-wrap:wrap}
.pagenav a{background:#fff;border:1px solid var(--line);border-radius:10px;padding:10px 18px;text-decoration:none;color:var(--accent);font-size:14px;font-weight:600}
.pagenav a:hover{background:var(--accent-soft)}
footer{color:var(--muted);font-size:12px;text-align:center;padding:28px 20px 48px;line-height:1.8}
a:focus-visible,.card:focus-visible,.searchbox input:focus-visible{outline:2px solid var(--accent);outline-offset:2px}
@media(min-width:641px) and (max-width:1024px){
  .wrap{max-width:920px}
  .hero{padding:48px 0 8px}.hero h1{font-size:34px}
  .grid{grid-template-columns:repeat(2,1fr)}
  article{padding:30px 32px}
  .practice{padding:26px 28px}
}
@media(max-width:640px){
  .hero{padding:40px 0 6px}.hero h1{font-size:30px}
  .hero p{font-size:14px}
  header.site .wrap{gap:10px;padding:10px 16px}
  .logo{font-size:17px}
  .searchbox{flex:1 1 100%;max-width:none;min-width:0}
  .searchbox input{font-size:16px;padding:10px 14px}
  article{padding:24px 20px;overflow-wrap:break-word}
  article h1{font-size:23px}
  article h2{font-size:18px;margin:32px 0 10px}
  .grid{grid-template-columns:1fr;gap:14px}
  .card{padding:18px 18px 16px}
  .card h3{font-size:18px;padding-right:56px}
  table{font-size:13px}
  th,td{padding:8px 10px}
  .q{padding:14px}
  .qtext{font-size:14px}
  .opt{font-size:15px;padding:12px 14px;min-height:44px}
  .showans,.pagenav a{min-height:44px;display:inline-flex;align-items:center;justify-content:center}
  .pagenav a{flex:1 1 100%;text-align:center}
  .psubj-head{flex-wrap:wrap}
}
@media(max-width:380px){
  .hero h1{font-size:26px}
  .wrap{padding:0 16px}
  article{padding:20px 16px}
}
@media(prefers-reduced-motion:reduce){.card{transition:none}.card:hover{transform:none}}
/* 今日练习 */
.practice{background:var(--card);border:1px solid var(--line);border-radius:16px;padding:28px 32px;margin:8px 0 40px}
.phead{display:flex;align-items:baseline;gap:14px;flex-wrap:wrap;margin-bottom:6px}
.phead h2{font-family:Georgia,"Songti SC","STSong","Noto Serif SC",serif;font-size:24px;margin:0}
.phead p{margin:0;font-size:13px;color:var(--muted)}
.ploading{color:var(--muted);font-size:14px}
.psubj{border-top:1px solid var(--line);padding:20px 0 8px;margin-top:14px}
.psubj:first-of-type{border-top:none}
.psubj-head{display:flex;align-items:center;gap:12px;margin-bottom:6px}
.psubj-name{font-size:17px;font-weight:700;color:var(--accent);border-left:4px solid var(--accent);padding-left:10px}
.pscore{font-size:12px;color:var(--muted);margin-left:auto}
.q{margin:16px 0;padding:16px;border:1px solid var(--line);border-radius:12px;background:#FDFCF9}
.qtext{margin:0 0 10px;font-size:15px;font-weight:600}
.opts{display:grid;gap:8px}
.opt{text-align:left;font-family:inherit;font-size:14px;padding:10px 14px;border:1px solid var(--line);border-radius:10px;background:#fff;cursor:pointer;color:var(--ink);transition:border-color .15s ease,background .15s ease}
.opt:hover:not(:disabled){border-color:var(--accent)}
.opt.correct{border-color:#16A34A;background:#F0FDF4;font-weight:700}
.opt.wrong{border-color:#DC2626;background:#FEF2F2}
.explain{margin:10px 0 0;font-size:13px;color:var(--muted);background:#fff;border-left:3px solid var(--accent);padding:8px 12px;border-radius:0 8px 8px 0}
.showans{font-family:inherit;font-size:13px;padding:8px 16px;border:1px solid var(--line);border-radius:999px;background:#fff;color:var(--accent);cursor:pointer;font-weight:600}
.showans:hover{background:var(--accent-soft,#EEF2FF)}
.answer{margin-top:10px;font-size:14px}
.answer.hidden{display:none}
.answer p{margin:8px 0}
/* 错题本 */
#errorbook{margin-top:8px}
.eb-item{background:#FFFBF5}
.opt.eb-static{cursor:default}
.opt.eb-static:hover{border-color:var(--line)}
.eb-note{margin:10px 0 0;font-size:13px;font-weight:600}
.eb-del{font-family:inherit;font-size:12px;padding:4px 12px;border:1px solid var(--line);border-radius:999px;background:#fff;color:var(--muted);cursor:pointer;margin-left:auto}
.eb-del:hover{color:#DC2626;border-color:#DC2626}
.btnrow{display:flex;gap:8px;flex-wrap:wrap}
.showans:disabled{opacity:.55;cursor:default}
#ebactions{margin-top:6px}
@media(max-width:640px){.practice{padding:20px}}