:root{
  --bg:#f4f6fb; --card:#ffffff; --text:#1f2937; --muted:#6b7280; --line:#e6e9f0;
  --primary:#2563eb; --primary-d:#1d4ed8; --primary-l:#eff4ff;
  --accent:#7c3aed; --ok:#16a34a; --ok-l:#e9f8ee; --bad:#dc2626; --bad-l:#fdecec;
  --warn:#d97706; --radius:14px; --shadow:0 1px 3px rgba(16,24,40,.06),0 8px 24px rgba(16,24,40,.05);
}
*{box-sizing:border-box;-webkit-tap-highlight-color:transparent}
html,body{margin:0;padding:0}
body{
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;
  background:var(--bg); color:var(--text); line-height:1.7; font-size:15px;
}
a{color:var(--primary);text-decoration:none}
.container{max-width:1000px;margin:0 auto;padding:0 16px 64px}

/* ---------- header ---------- */
.topbar{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.92);backdrop-filter:blur(8px);border-bottom:1px solid var(--line)}
.topbar .inner{max-width:1000px;margin:0 auto;padding:10px 16px;display:flex;align-items:center;gap:14px;flex-wrap:wrap}
.brand{display:flex;align-items:center;gap:9px;font-weight:700;font-size:16px;color:var(--text)}
.brand .logo{width:28px;height:28px;border-radius:8px;background:linear-gradient(135deg,var(--primary),var(--accent));color:#fff;display:grid;place-items:center;font-size:15px;font-weight:800}
.brand small{font-weight:500;color:var(--muted);font-size:12px}
.nav{margin-left:auto;display:flex;gap:4px;flex-wrap:wrap}
.nav a{padding:7px 12px;border-radius:9px;color:var(--muted);font-size:14px;font-weight:500}
.nav a:hover{background:var(--primary-l);color:var(--primary)}
.nav a.on{background:var(--primary);color:#fff}

/* ---------- generic ---------- */
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow)}
.pad{padding:18px}
h1,h2,h3{margin:0 0 6px}
h1{font-size:24px}h2{font-size:18px}h3{font-size:15px}
.muted{color:var(--muted)}
.small{font-size:13px}
.center{text-align:center}
.row{display:flex;gap:12px;flex-wrap:wrap}
.row.between{justify-content:space-between;align-items:center}
.spacer{flex:1}
.hr{height:1px;background:var(--line);margin:14px 0;border:0}
.pill{display:inline-block;padding:2px 9px;border-radius:999px;font-size:12px;background:var(--primary-l);color:var(--primary);font-weight:600}
.pill.gray{background:#f1f3f7;color:var(--muted)}
.pill.ok{background:var(--ok-l);color:var(--ok)}
.pill.bad{background:var(--bad-l);color:var(--bad)}

.btn{display:inline-flex;align-items:center;justify-content:center;gap:6px;padding:10px 18px;border-radius:10px;border:1px solid var(--line);background:#fff;color:var(--text);font-size:14px;font-weight:600;cursor:pointer;transition:.15s}
.btn:hover{border-color:#cfd6e4;background:#fafbff}
.btn.primary{background:var(--primary);border-color:var(--primary);color:#fff}
.btn.primary:hover{background:var(--primary-d)}
.btn.ghost{background:transparent}
.btn.sm{padding:6px 12px;font-size:13px;border-radius:8px}
.btn:disabled{opacity:.5;cursor:not-allowed}
.btn.danger{color:var(--bad);border-color:#f3c9c9}

/* ---------- dashboard ---------- */
.hero{margin:22px 0 18px}
.hero h1 span{background:linear-gradient(90deg,var(--primary),var(--accent));-webkit-background-clip:text;background-clip:text;color:transparent}
.stats{display:grid;grid-template-columns:repeat(4,1fr);gap:12px;margin:18px 0}
.stat{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:16px;box-shadow:var(--shadow)}
.stat .n{font-size:26px;font-weight:800;letter-spacing:-.5px}
.stat .l{color:var(--muted);font-size:13px;margin-top:2px}
.stat.b .n{color:var(--primary)}.stat.g .n{color:var(--ok)}.stat.r .n{color:var(--bad)}.stat.o .n{color:var(--warn)}

.grid{display:grid;gap:12px}
.grid.c2{grid-template-columns:1fr 1fr}
.grid.c3{grid-template-columns:repeat(3,1fr)}
.chip{display:flex;align-items:center;gap:10px;padding:12px 14px;border:1px solid var(--line);border-radius:12px;background:#fff;cursor:pointer;transition:.15s}
.chip:hover{border-color:var(--primary);background:var(--primary-l);transform:translateY(-1px)}
.chip .ico{width:34px;height:34px;border-radius:10px;background:var(--primary-l);color:var(--primary);display:grid;place-items:center;font-weight:800;font-size:14px;flex:0 0 auto}
.chip .t{font-weight:600;font-size:14px}
.chip .s{color:var(--muted);font-size:12px}
.chip .go{margin-left:auto;color:var(--muted)}

.section-title{display:flex;align-items:center;gap:8px;margin:26px 0 12px}
.section-title h2{font-size:17px}
.section-title .line{flex:1;height:1px;background:var(--line)}

/* ---------- progress bar ---------- */
.bar{height:8px;border-radius:999px;background:#eef1f7;overflow:hidden}
.bar>i{display:block;height:100%;background:linear-gradient(90deg,var(--primary),var(--accent));border-radius:999px;transition:width .3s}

/* ---------- question ---------- */
.qhead{display:flex;align-items:center;gap:10px;flex-wrap:wrap;margin-bottom:12px}
.qstem{font-size:17px;font-weight:600;line-height:1.8;white-space:pre-wrap;word-break:break-word}
.opts{margin:16px 0 0;display:grid;gap:10px}
.opt{display:flex;gap:11px;align-items:flex-start;padding:13px 15px;border:1.5px solid var(--line);border-radius:12px;background:#fff;cursor:pointer;transition:.13s;text-align:left;font-size:15px;color:var(--text);width:100%}
.opt:hover{border-color:#bfcbee;background:#fbfcff}
.opt .k{flex:0 0 26px;height:26px;border-radius:8px;background:#f1f3f7;color:var(--muted);display:grid;place-items:center;font-weight:700;font-size:13px}
.opt .v{flex:1;white-space:pre-wrap;word-break:break-word}
.opt.picked{border-color:var(--primary);background:var(--primary-l)}
.opt.picked .k{background:var(--primary);color:#fff}
.opt.correct{border-color:var(--ok);background:var(--ok-l)}
.opt.correct .k{background:var(--ok);color:#fff}
.opt.wrong{border-color:var(--bad);background:var(--bad-l)}
.opt.wrong .k{background:var(--bad);color:#fff}
.opt.locked{cursor:default}
.opt.locked:hover{border-color:inherit;background:inherit}

.explain{margin-top:16px;padding:14px 16px;border-radius:12px;background:#f7f9fc;border:1px dashed #d8dfec}
.explain h4{margin:0 0 6px;font-size:13px;color:var(--muted);letter-spacing:.5px}
.explain .ans{font-weight:700;color:var(--ok)}
.explain .body{white-space:pre-wrap;word-break:break-word;font-size:14px;color:#374151}

.toolbar{display:flex;gap:8px;flex-wrap:wrap;align-items:center;margin-top:18px}
.qnav{display:flex;gap:8px;justify-content:space-between;margin-top:16px}

/* ---------- knowledge ---------- */
.kcard{padding:15px 17px;border:1px solid var(--line);border-radius:12px;background:#fff;margin-bottom:10px;cursor:pointer}
.kcard:hover{border-color:#cfd8ea}
.kcard .kt{font-weight:700;font-size:15px}
.kcard .kb{margin-top:9px;font-size:14px;color:#374151;line-height:1.95;overflow-wrap:anywhere}
/* 正文重排后的块：段落 / 小标题 / 列表 / 口诀 */
.kcard .kb>.kbp{margin:0 0 7px}
.kcard .kb>.kbh{margin:0 0 6px;font-weight:700;color:#111827}
.kcard .kb>.kbp:last-child,.kcard .kb>.kbh:last-child,
.kcard .kb>.kblist:last-child,.kcard .kb>.kbq:last-child{margin-bottom:0}
.kcard .kb>.kblist{margin:1px 0 8px;padding:2px 0 2px 9px;border-left:2px solid #e7edfa;border-radius:2px}
.kcard .kb .kbli{display:flex;gap:.5em;align-items:baseline;margin:0 0 4px}
.kcard .kb .kbli:last-child{margin-bottom:0}
.kbli-m{flex:0 0 auto;font-style:normal;font-weight:700;letter-spacing:.5px;color:#8a98b3}
.kbl-n .kbli-m{min-width:2.6em}
.kbl-d .kbli-m{min-width:1.1em;color:#c6d0e2}
.kbli-c{flex:1 1 auto;min-width:0}
.kcard .kb>.kbq{margin:0 0 6px;padding:2px 10px 2px 9px;border-left:3px solid #f0c86a;
  background:linear-gradient(90deg,rgba(250,204,21,.13),rgba(250,204,21,0));border-radius:0 6px 6px 0}
.kbq-t{display:inline-block;margin-right:7px;padding:0 5px;border-radius:4px;background:#fdeec4;
  color:#8a6106;font-size:11.5px;font-weight:700;line-height:1.75;vertical-align:1.5px}
.kcard .meta{margin-top:6px;font-size:12px;color:var(--muted)}

/* ---------- 三色笔记：还原原书的红/蓝文字标记 ---------- */
.hl-red{color:#d8232f;font-weight:600;background:linear-gradient(transparent 64%,rgba(216,35,47,.15) 0);padding:0 1px;border-radius:2px}
.hl-blue{color:#2c52b0;font-weight:600;background:linear-gradient(transparent 64%,rgba(44,82,176,.14) 0);padding:0 1px;border-radius:2px}
.lv{display:inline-block;margin-right:7px;padding:1px 7px;border-radius:6px;font-size:11.5px;font-weight:700;line-height:1.6;vertical-align:1.5px}
.lv-red{background:#fdecec;color:#c81e2a;border:1px solid #f6c6ca}
.lv-blue{background:#eef2fd;color:#2c52b0;border:1px solid #cbd8f5}
.t-red{color:#c81e2a}
.t-blue{color:#2c52b0}
.legend{display:flex;gap:6px 16px;flex-wrap:wrap;align-items:center;margin:0 0 12px;padding:9px 13px;background:#fbfcfe;border:1px dashed #d8dfec;border-radius:11px;font-size:12.5px;color:var(--muted)}
.legend-t{font-weight:600;color:#374151}
.legend .dot{display:inline-block;width:9px;height:9px;border-radius:50%;margin-right:5px}
.dot-r{background:#d8232f}
.dot-b{background:#2c52b0}
.dot-k{background:#1f2937}
/* 卡片 → 原书图集 的跳转 */
.imgjump{display:inline-block;padding:1px 8px;border-radius:6px;background:var(--primary-l);color:var(--primary);font-weight:600;font-size:12px}
.imgjump:hover{background:#dfe8ff;text-decoration:none}
.hidden-body{display:none}
mark{background:#fff3c4;padding:0 2px;border-radius:3px}

.filters{display:flex;gap:10px;flex-wrap:wrap;align-items:center;margin:14px 0}
/* 下拉里可能有过长的来源名，必须允许收缩，否则会撑破页面宽度 */
.filters>select{min-width:0;max-width:100%;text-overflow:ellipsis}
select,input[type=text],input[type=search]{padding:9px 12px;border:1px solid var(--line);border-radius:10px;font-size:14px;background:#fff;color:var(--text);outline:none;font-family:inherit}
select:focus,input:focus{border-color:var(--primary)}
input[type=search]{min-width:220px;flex:1}

.empty{padding:40px 16px;text-align:center;color:var(--muted)}

.toast{position:fixed;left:50%;bottom:28px;transform:translateX(-50%) translateY(60px);background:#111827;color:#fff;padding:10px 18px;border-radius:10px;font-size:14px;opacity:0;transition:.25s;z-index:200}
.toast.show{opacity:1;transform:translateX(-50%) translateY(0)}

/* ---------- 安装到桌面 ---------- */
.install-btn{margin-left:12px;padding:7px 15px;border:0;border-radius:999px;cursor:pointer;font-family:inherit;
  background:linear-gradient(135deg,var(--primary),var(--accent));color:#fff;font-size:13px;font-weight:700;
  box-shadow:0 2px 8px rgba(37,99,235,.28)}
.install-btn[hidden]{display:none}

/* ---------- 底部标签栏（仅手机端显示） ---------- */
.tabbar{display:none}

/* ---------- 安装说明弹层 ---------- */
.sheet-mask{position:fixed;inset:0;z-index:300;display:flex;align-items:flex-end;justify-content:center;
  padding:16px;background:rgba(15,23,42,.45);animation:fade .18s ease}
.sheet{width:100%;max-width:460px;background:#fff;border-radius:18px;padding:20px;
  padding-bottom:calc(20px + env(safe-area-inset-bottom,0px));box-shadow:0 20px 50px rgba(15,23,42,.28);
  animation:rise .22s ease}
.sheet h3{font-size:17px;margin-bottom:6px}
.steps{margin:14px 0 0;padding-left:21px;color:#374151;font-size:14.5px;line-height:2.05}
.steps b{color:var(--primary)}
@keyframes fade{from{opacity:0}to{opacity:1}}
@keyframes rise{from{transform:translateY(26px);opacity:.4}to{transform:none;opacity:1}}

/* ================= 手机端 ================= */
@media (max-width:720px){
  body{font-size:14.5px;-webkit-text-size-adjust:100%}
  .stats{grid-template-columns:1fr 1fr}
  .grid.c3{grid-template-columns:1fr}
  .grid.c2{grid-template-columns:1fr}
  .nav{display:none}
  .qstem{font-size:16px}
  h1{font-size:21px}
  .hero h1{font-size:22px}
  .brand small{display:none}
  .install-btn{margin-left:auto;padding:7px 13px;font-size:12.5px}
  /* 给底部标签栏留出空间，并适配刘海屏 */
  .container{padding:0 12px calc(86px + env(safe-area-inset-bottom,0px))}
  .topbar .inner{padding-top:calc(8px + env(safe-area-inset-top,0px))}

  .tabbar{
    display:flex;position:fixed;left:0;right:0;bottom:0;z-index:120;
    background:rgba(255,255,255,.96);backdrop-filter:blur(10px);
    border-top:1px solid var(--line);padding-bottom:env(safe-area-inset-bottom,0px);
  }
  .tabbar a{flex:1;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:3px;
    padding:8px 0 7px;color:var(--muted);font-size:11px;font-weight:600;line-height:1;transition:.15s}
  .tabbar a svg{width:22px;height:22px}
  .tabbar a.on{color:var(--primary)}
  .tabbar a:active{background:#f1f4fb}

  /* 触控目标放大 */
  .btn{padding:12px 16px}
  .btn.sm{padding:9px 13px;font-size:13.5px}
  .opt{padding:15px}
  .chip{padding:14px}
  .qnav .btn{flex:1;min-width:94px}
  .qnav{flex-wrap:wrap;gap:8px}

  /* 防止 iOS 聚焦输入框时页面被放大 */
  select,input[type=text],input[type=search]{font-size:16px}
  /* 搜索框独占一行，三个下拉两两排开 —— 否则会被挤成一致的“全…”无法区分 */
  .filters{gap:8px}
  .filters>input[type=search]{flex:1 1 100%;min-width:0;width:100%}
  .filters>select{flex:0 1 calc(50% - 4px);min-width:0;max-width:none}

  .toast{bottom:calc(78px + env(safe-area-inset-bottom,0px))}
}

/* 已安装为独立 App 时的额外适配 */
@media (display-mode:standalone){
  .topbar .inner{padding-top:calc(8px + env(safe-area-inset-top,0px))}
}

/* ---------- 原书图集 ---------- */
.gal-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(190px,1fr));gap:12px}
.gal-item{margin:0;border:1px solid var(--line);border-radius:12px;background:#fff;overflow:hidden;cursor:zoom-in;position:relative;transition:.18s}
.gal-item:hover{border-color:#cfd8ea;box-shadow:var(--shadow);transform:translateY(-1px)}
.gal-item img{display:block;width:100%;height:170px;object-fit:contain;background:#f7f9fc}
.gal-item figcaption{padding:7px 10px;font-size:12px;color:var(--muted);border-top:1px solid var(--line);line-height:1.5}
.gal-item figcaption b{color:#374151;font-weight:600}
.gal-tag{position:absolute;top:8px;left:8px;padding:1px 7px;border-radius:6px;background:rgba(37,99,235,.92);color:#fff;font-size:11px;font-weight:600}
.gal-hit{box-shadow:0 0 0 3px rgba(37,99,235,.55),var(--shadow);border-color:var(--primary)}

.lightbox{position:fixed;inset:0;z-index:300;background:rgba(15,23,42,.94);display:flex;flex-direction:column}
.lightbox[hidden]{display:none}
.lb-top{display:flex;align-items:center;gap:10px;padding:10px 14px;padding-top:calc(10px + env(safe-area-inset-top,0px));color:#e5e7eb;font-size:13.5px}
.lb-title{flex:1;min-width:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.lb-actions{display:flex;gap:8px}
.lb-btn{background:rgba(255,255,255,.14);color:#fff;border:0;border-radius:9px;padding:8px 13px;font-size:13px;font-family:inherit;cursor:pointer;text-decoration:none;line-height:1.4;white-space:nowrap}
.lb-btn:hover{background:rgba(255,255,255,.26)}
.lb-stage{flex:1;min-height:0;display:flex;align-items:center;justify-content:center;padding:0 12px;overflow:auto}
.lb-stage img{max-width:100%;max-height:100%;width:auto;height:auto;object-fit:contain;background:#fff;border-radius:6px}
.lb-nav{display:flex;align-items:center;justify-content:space-between;gap:10px;padding:12px 14px;padding-bottom:calc(12px + env(safe-area-inset-bottom,0px))}
.lb-pos{color:#9ca3af;font-size:13px}
body.lb-lock{overflow:hidden}

@media (max-width:720px){
  .gal-grid{grid-template-columns:repeat(2,1fr);gap:9px}
  .gal-item img{height:132px}
  .gal-item figcaption{font-size:11.5px;padding:6px 8px}
  .lb-title{font-size:12.5px}
}

/* ================= 分组导航：次级标签行 =================
   一级入口只有 5 个（首页/刷题/背诵/复盘/我的），组内页用这一行切换。
   单页组（首页、我的）不渲染此行，避免出现只有一枚标签的怪样子。 */
.subnav{max-width:1000px;margin:0 auto;padding:9px 16px 10px;display:flex;gap:6px;flex-wrap:wrap;
  border-top:1px solid var(--line)}
.subnav a{padding:5px 12px;border-radius:999px;background:#f1f3f7;color:var(--muted);font-size:13px;font-weight:600}
.subnav a:hover{background:#e8eefb;color:var(--primary)}
.subnav a.on{background:var(--primary);color:#fff}

/* ================= 首页驾驶舱 ================= */
.dash-hero{display:flex;align-items:flex-end;justify-content:space-between;gap:14px;flex-wrap:wrap;margin:24px 0 16px}
.dash-hero h1{margin:0;font-size:23px}
.dash-hero .sub{color:var(--muted);font-size:13.5px;margin-top:3px}

.resume{display:flex;align-items:center;gap:15px;padding:16px 18px;border:1px solid #cbdcfb;border-radius:14px;
  background:linear-gradient(135deg,#eff4ff,#f8fbff);box-shadow:var(--shadow)}
.resume .rb{flex:1;min-width:0}
.resume .rl{font-size:12.5px;color:var(--primary);font-weight:700}
.resume .rt{font-size:16.5px;font-weight:800;margin-top:3px;word-break:break-word}
.resume .rs{font-size:12.5px;color:var(--muted);margin-top:3px}
.resume.plain{border-style:dashed;border-color:var(--line);background:#fbfcfe}
.resume.plain .rl{color:var(--muted)}

.metrics{display:grid;grid-template-columns:repeat(4,1fr);gap:10px;margin:14px 0 0}
.metric{background:var(--card);border:1px solid var(--line);border-radius:12px;padding:12px 14px}
.metric .n{font-size:21px;font-weight:800;letter-spacing:-.3px;line-height:1.3}
.metric .l{font-size:12.5px;color:var(--muted);margin-top:2px}
.metric.b .n{color:var(--primary)}.metric.g .n{color:var(--ok)}
.metric.r .n{color:var(--bad)}.metric.o .n{color:var(--warn)}
.metric .l b{color:#374151}

.entries{display:grid;grid-template-columns:repeat(4,1fr);gap:12px;margin-top:14px}
.entry{display:block;padding:16px;border:1px solid var(--line);border-radius:14px;background:#fff;
  box-shadow:var(--shadow);transition:.15s}
.entry:hover{border-color:var(--primary);transform:translateY(-2px)}
.entry .ei{width:38px;height:38px;border-radius:11px;display:grid;place-items:center;font-weight:800;
  font-size:15px;margin-bottom:9px}
.entry .et{font-weight:700;font-size:15px}
.entry .es{font-size:12.5px;color:var(--muted);margin-top:3px;line-height:1.65}
.entry.drill .ei{background:#eff4ff;color:#2563eb}
.entry.read .ei{background:#f3e8ff;color:#7c3aed}
.entry.review .ei{background:#fef3c7;color:#b45309}
.entry.me .ei{background:#e9f8ee;color:#15803d}

/* 次要动作（随机刷题/错题重做/收藏/背诵模式）—— 与四个主入口明显拉开层级 */
.quick{display:flex;gap:8px;flex-wrap:wrap;margin-top:14px}
.quick a{padding:7px 13px;border:1px solid var(--line);border-radius:999px;background:#fff;
  font-size:13px;color:var(--muted);font-weight:600}
.quick a:hover{border-color:var(--primary);color:var(--primary);background:var(--primary-l)}

/* 折叠区：把「章节进度」「真题列表」这类长清单收起来，首页只留一行标题 */
.fold{border:1px solid var(--line);border-radius:14px;background:#fff;box-shadow:var(--shadow);margin-top:12px}
.fold>summary{list-style:none;cursor:pointer;padding:15px 18px;display:flex;align-items:center;gap:10px;
  font-weight:700;font-size:14.5px}
.fold>summary::-webkit-details-marker{display:none}
.fold>summary .fmeta{margin-left:auto;color:var(--muted);font-size:12.5px;font-weight:500}
.fold>summary .chev{color:var(--muted);font-size:17px;line-height:1;transition:transform .18s}
.fold[open]>summary .chev{transform:rotate(90deg)}
.fold[open]>summary{border-bottom:1px solid var(--line)}
.fold .fbody{padding:14px 18px 18px}

/* 数据来源说明：把原来的文字墙拆成一行一条 */
.srclist{display:grid;gap:8px}
.srcrow{display:flex;gap:10px;align-items:baseline;padding:10px 13px;border:1px solid var(--line);
  border-radius:11px;font-size:13px;line-height:1.75}
.srcrow .sn{flex:1;min-width:0}
.srcrow .sn b{color:#374151}
.srcrow .sc{color:var(--muted);font-size:12.5px;white-space:nowrap;font-weight:600}

@media (max-width:720px){
  .subnav{padding:8px 12px 9px;flex-wrap:nowrap;overflow-x:auto;scrollbar-width:none}
  .subnav::-webkit-scrollbar{display:none}
  .subnav a{flex:0 0 auto}
  .dash-hero{margin:18px 0 14px;align-items:flex-start}
  .dash-hero h1{font-size:21px}
  .metrics{grid-template-columns:1fr 1fr}
  .entries{grid-template-columns:1fr 1fr;gap:10px}
  .entry{padding:13px}
  .entry .ei{width:32px;height:32px;font-size:13px;border-radius:9px;margin-bottom:7px}
  .entry .et{font-size:14px}
  .entry .es{font-size:11.5px}
  .resume{padding:14px 15px}
  .resume .rt{font-size:15px}
  .fold>summary{padding:13px 15px;font-size:14px}
  .fold .fbody{padding:12px 15px 15px}
}