/* 小五学伴 · 设计系统 */
:root{
  --bg:#F7F4EE;
  --bg-grad:radial-gradient(1200px 600px at 100% -10%, #FFF3E8 0%, rgba(255,243,232,0) 60%),
            radial-gradient(900px 500px at -10% 110%, #EAF2FF 0%, rgba(234,242,255,0) 55%);
  --surface:#FFFFFF;
  --surface-2:#FCFAF6;
  --ink:#1C1917;
  --ink-2:#46403A;
  --muted:#8B8074;
  --faint:#B6ADA1;
  --line:#EDE5DA;
  --line-2:#F4EEE5;
  --brand:#E4572E;
  --brand-2:#C7451F;
  --brand-soft:#FDEDE6;
  --blue:#2F6FEB;
  --blue-soft:#EAF1FE;
  --green:#2E9E6B;
  --green-soft:#E8F6EF;
  --amber:#E39A2B;
  --amber-soft:#FDF3E0;
  --purple:#7A5AF8;
  --purple-soft:#F0ECFE;
  --red:#D64545;
  --red-soft:#FDECEC;
  --r:20px;
  --r-md:16px;
  --r-sm:12px;
  --shadow:0 1px 2px rgba(28,25,23,.04), 0 10px 30px -18px rgba(28,25,23,.28);
  --shadow-lg:0 2px 6px rgba(28,25,23,.05), 0 24px 60px -28px rgba(28,25,23,.3);
  --font:-apple-system,BlinkMacSystemFont,"PingFang SC","HarmonyOS Sans SC","Microsoft YaHei",system-ui,sans-serif;
  --mono:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
}
*{box-sizing:border-box}
html,body{margin:0;padding:0}
html{-webkit-text-size-adjust:100%}
body{
  font-family:var(--font);
  background:var(--bg);
  background-image:var(--bg-grad);
  background-attachment:fixed;
  color:var(--ink);
  font-size:16px;
  line-height:1.6;
  -webkit-font-smoothing:antialiased;
}
button,input,select,textarea{font-family:inherit;font-size:inherit;color:inherit}
a{color:inherit;text-decoration:none}
h1,h2,h3,h4,p{margin:0}
ul,ol{margin:0;padding:0;list-style:none}
::selection{background:#FFD9C7}

/* ---------- 布局 ---------- */
.app{min-height:100vh;display:grid;grid-template-columns:248px 1fr}
.side{
  position:sticky;top:0;height:100vh;display:flex;flex-direction:column;
  padding:22px 16px 18px;border-right:1px solid var(--line);
  background:rgba(255,253,249,.72);backdrop-filter:blur(12px);
}
.brand{display:flex;gap:11px;align-items:center;padding:4px 8px 22px}
.brand-mark{
  width:38px;height:38px;border-radius:12px;flex:none;
  background:linear-gradient(145deg,#F0703F,#D8441F);
  color:#fff;font-weight:700;font-size:19px;display:grid;place-items:center;
  box-shadow:0 6px 16px -6px rgba(212,68,31,.7);letter-spacing:0;
}
.brand-text{display:flex;flex-direction:column;line-height:1.25}
.brand-text strong{font-size:16px;letter-spacing:.2px}
.brand-text span{font-size:11.5px;color:var(--muted);letter-spacing:.6px}
.side-nav{display:flex;flex-direction:column;gap:2px}
.side-item{
  display:flex;align-items:center;gap:11px;padding:10px 12px;border-radius:12px;
  font-size:14.5px;color:var(--ink-2);transition:.16s;font-weight:500;
}
.side-item .ico{width:20px;text-align:center;font-size:15px;color:var(--faint);transition:.16s}
.side-item:hover{background:#fff;color:var(--ink)}
.side-item.active{background:#fff;color:var(--brand-2);box-shadow:var(--shadow);font-weight:600}
.side-item.active .ico{color:var(--brand)}
.side-foot{margin-top:auto;padding-top:16px}
.side-note{
  background:#fff;border:1px solid var(--line);border-radius:14px;padding:12px;
  display:flex;flex-direction:column;gap:4px;margin-bottom:10px;
}
.side-note b{font-size:12px;color:var(--brand-2);letter-spacing:.4px}
.side-note span{font-size:11.5px;color:var(--muted);line-height:1.5}

.body{min-width:0;display:flex;flex-direction:column}
.topbar{
  position:sticky;top:0;z-index:30;display:flex;align-items:center;justify-content:space-between;
  gap:12px;padding:14px 32px;border-bottom:1px solid transparent;
  background:linear-gradient(180deg,rgba(247,244,238,.95),rgba(247,244,238,.78));
  backdrop-filter:blur(14px);
}
.topbar-l{display:flex;align-items:center;gap:12px;min-width:0}
.avatar{
  width:40px;height:40px;border-radius:14px;flex:none;display:grid;place-items:center;
  background:linear-gradient(145deg,#FFE2C9,#FFC9A8);color:#9A3E13;font-weight:700;font-size:17px;
  border:1px solid #fff;
}
.topbar-info{display:flex;flex-direction:column;min-width:0}
.topbar-info .hi{font-size:15.5px;font-weight:650;letter-spacing:.2px}
.topbar-info .sub{font-size:12px;color:var(--muted);white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.topbar-r{display:flex;gap:8px}
.icon-btn{
  width:38px;height:38px;border-radius:12px;border:1px solid var(--line);background:#fff;
  color:var(--ink-2);cursor:pointer;display:grid;place-items:center;font-size:16px;transition:.15s;
}
.icon-btn:hover{border-color:#DCD1C2;transform:translateY(-1px)}
.view{flex:1;padding:8px 32px 56px;max-width:1180px;width:100%;margin:0 auto}
.boot{display:flex;flex-direction:column;align-items:center;gap:14px;padding:120px 0;color:var(--muted)}
.spinner{
  width:26px;height:26px;border-radius:50%;border:2.5px solid var(--line);border-top-color:var(--brand);
  animation:spin .8s linear infinite;
}
@keyframes spin{to{transform:rotate(360deg)}}

.tabbar{display:none}

/* ---------- 通用组件 ---------- */
.page-head{display:flex;align-items:flex-end;justify-content:space-between;gap:16px;margin:14px 0 20px;flex-wrap:wrap}
.page-title{font-size:23px;font-weight:700;letter-spacing:-.2px;line-height:1.3}
.page-desc{font-size:13px;color:var(--muted);margin-top:5px;max-width:62ch}
.eyebrow{font-size:11.5px;letter-spacing:1.4px;text-transform:uppercase;color:var(--faint);font-weight:600}

.card{background:var(--surface);border:1px solid var(--line);border-radius:var(--r);box-shadow:var(--shadow)}
.card-pad{padding:20px 22px}
.grid{display:grid;gap:14px}
.g2{grid-template-columns:repeat(2,minmax(0,1fr))}
.g3{grid-template-columns:repeat(3,minmax(0,1fr))}
.g4{grid-template-columns:repeat(4,minmax(0,1fr))}
.row{display:flex;align-items:center;gap:10px}
.row-between{display:flex;align-items:center;justify-content:space-between;gap:12px}
.wrap{flex-wrap:wrap}
.spacer{flex:1}
.mt8{margin-top:8px}.mt12{margin-top:12px}.mt16{margin-top:16px}.mt20{margin-top:20px}.mt24{margin-top:24px}
.muted{color:var(--muted)}
.tiny{font-size:12px}
.small{font-size:13px}

.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:7px;
  height:42px;padding:0 18px;border-radius:12px;border:1px solid var(--line);
  background:#fff;color:var(--ink);font-weight:600;font-size:14.5px;cursor:pointer;
  transition:.15s;white-space:nowrap;
}
.btn:hover{border-color:#DBCFBE;transform:translateY(-1px)}
.btn:active{transform:translateY(0)}
.btn:disabled{opacity:.5;cursor:not-allowed;transform:none}
.btn-primary{background:linear-gradient(180deg,#EF6A3E,#DC4E20);border-color:#C7451F;color:#fff;box-shadow:0 8px 20px -10px rgba(220,78,32,.8)}
.btn-primary:hover{border-color:#B33C19}
.btn-soft{background:var(--brand-soft);border-color:#F8DACD;color:var(--brand-2)}
.btn-ghost{background:transparent;border-color:transparent;color:var(--muted)}
.btn-ghost:hover{background:#fff;border-color:var(--line);color:var(--ink)}
.btn-sm{height:34px;padding:0 12px;font-size:13px;border-radius:10px}
.btn-lg{height:50px;font-size:16px;border-radius:14px}
.btn-block{width:100%}
.btn-ink{background:var(--ink);border-color:var(--ink);color:#fff}

.chip{
  display:inline-flex;align-items:center;gap:6px;height:30px;padding:0 11px;border-radius:99px;
  background:var(--surface-2);border:1px solid var(--line);font-size:12.5px;color:var(--ink-2);
  cursor:pointer;transition:.15s;white-space:nowrap;
}
.chip:hover{background:#fff;border-color:#DED3C3}
.chip.on{background:var(--ink);border-color:var(--ink);color:#fff}
.chip-static{cursor:default}
.chip-dot{width:6px;height:6px;border-radius:50%;background:currentColor;opacity:.6}

.badge{
  display:inline-flex;align-items:center;gap:5px;height:22px;padding:0 8px;border-radius:7px;
  font-size:11.5px;font-weight:650;letter-spacing:.2px;
}
.badge-brand{background:var(--brand-soft);color:var(--brand-2)}
.badge-blue{background:var(--blue-soft);color:#1D53C0}
.badge-green{background:var(--green-soft);color:#1F7A52}
.badge-amber{background:var(--amber-soft);color:#9A6412}
.badge-gray{background:#F3EFE8;color:var(--muted)}
.badge-red{background:var(--red-soft);color:#B03737}

.field{display:flex;flex-direction:column;gap:7px;margin-bottom:14px}
.field>span{font-size:12.5px;font-weight:600;color:var(--ink-2)}
.field input,.field select,.field textarea,.input{
  height:46px;border-radius:12px;border:1px solid var(--line);background:#FCFAF6;
  padding:0 14px;font-size:15px;outline:none;transition:.15s;width:100%;
}
.field textarea{height:auto;padding:12px 14px;line-height:1.6;resize:vertical}
.field input:focus,.field select:focus,.field textarea:focus,.input:focus{
  border-color:#F0A98E;background:#fff;box-shadow:0 0 0 4px rgba(228,87,46,.08)
}
.field-row{display:flex;gap:10px}
.field-row input{flex:1}
.field-row .btn{height:46px;flex:none}

/* 进度环 */
.ring{
  --p:0;--sz:56px;--w:5px;
  width:var(--sz);height:var(--sz);border-radius:50%;flex:none;position:relative;
  background:conic-gradient(var(--rc,var(--brand)) calc(var(--p)*1%), #F0E9DE 0);
  display:grid;place-items:center;
}
.ring::after{content:"";position:absolute;inset:var(--w);background:#fff;border-radius:50%}
.ring b{position:relative;z-index:1;font-size:12.5px;font-weight:700;letter-spacing:-.3px}

/* 科目卡 */
.subj-card{
  position:relative;overflow:hidden;padding:18px 18px 16px;border-radius:var(--r);
  background:#fff;border:1px solid var(--line);box-shadow:var(--shadow);cursor:pointer;
  transition:.18s;display:flex;flex-direction:column;gap:12px;
}
.subj-card:hover{transform:translateY(-3px);box-shadow:var(--shadow-lg);border-color:#E3D8C8}
.subj-card::before{content:"";position:absolute;left:0;top:0;bottom:0;width:4px;background:var(--sc)}
.subj-head{display:flex;align-items:center;gap:10px}
.subj-glyph{
  width:40px;height:40px;border-radius:13px;display:grid;place-items:center;flex:none;
  font-weight:700;font-size:17px;color:#fff;background:var(--sc);
}
.subj-name{font-weight:700;font-size:16px}
.subj-meta{font-size:11.5px;color:var(--muted)}
.subj-stats{display:flex;gap:14px;font-size:12px;color:var(--muted)}
.subj-stats b{color:var(--ink);font-size:13.5px}

/* 首页 hero */
.hero{
  position:relative;overflow:hidden;border-radius:24px;padding:26px 26px 22px;
  background:linear-gradient(135deg,#FFF6EF 0%,#FFFDFA 46%,#F1F6FF 100%);
  border:1px solid var(--line);box-shadow:var(--shadow);
}
.hero::after{
  content:"";position:absolute;right:-60px;top:-70px;width:230px;height:230px;border-radius:50%;
  background:radial-gradient(circle at 30% 30%,rgba(255,203,171,.7),rgba(255,203,171,0) 68%);
}
.hero h2{font-size:25px;line-height:1.35;letter-spacing:-.3px;font-weight:750}
.hero .sub{font-size:13.5px;color:var(--ink-2);margin-top:8px;max-width:52ch}
.hero-actions{display:flex;gap:10px;margin-top:18px;flex-wrap:wrap}
.hero-stats{display:flex;gap:22px;margin-top:20px;flex-wrap:wrap}
.hstat{display:flex;flex-direction:column}
.hstat b{font-size:21px;font-weight:750;letter-spacing:-.4px}
.hstat span{font-size:11.5px;color:var(--muted)}

/* 列表行 */
.list{display:flex;flex-direction:column}
.li{
  display:flex;align-items:center;gap:13px;padding:13px 4px;border-bottom:1px solid var(--line-2);
  cursor:pointer;transition:.14s;
}
.li:last-child{border-bottom:none}
.li:hover{padding-left:8px;padding-right:8px;border-radius:10px;background:var(--surface-2)}
.li-idx{
  width:30px;height:30px;border-radius:9px;flex:none;display:grid;place-items:center;
  background:#F6F1E9;color:var(--muted);font-size:12px;font-weight:700;
}
.li-main{min-width:0;flex:1}
.li-title{font-size:14.5px;font-weight:600;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.li-sub{font-size:12px;color:var(--muted);margin-top:2px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.li-r{font-size:12px;color:var(--faint);flex:none;display:flex;align-items:center;gap:6px}

/* 课时讲解 */
.lesson-head{padding:22px 24px;border-radius:var(--r);background:#fff;border:1px solid var(--line);box-shadow:var(--shadow)}
.lesson-kicker{display:flex;gap:8px;align-items:center;flex-wrap:wrap;margin-bottom:10px}
.lesson-title{font-size:26px;font-weight:750;letter-spacing:-.4px;line-height:1.3}
.lesson-actions{display:flex;gap:8px;flex-wrap:wrap;margin-top:16px}

.tabs{display:flex;gap:4px;padding:4px;background:#F2EDE4;border-radius:12px;margin:18px 0 14px;width:fit-content;max-width:100%;overflow:auto}
.tab{
  height:34px;padding:0 14px;border:none;background:transparent;border-radius:9px;cursor:pointer;
  font-size:13.5px;font-weight:600;color:var(--muted);transition:.15s;white-space:nowrap;
}
.tab.on{background:#fff;color:var(--ink);box-shadow:0 1px 3px rgba(0,0,0,.06)}

.read{font-size:16.5px;line-height:1.95;color:var(--ink-2);letter-spacing:.1px}
.read h1,.read h2,.read h3{color:var(--ink);letter-spacing:-.2px;line-height:1.5}
.read h2{font-size:18px;margin:22px 0 8px;font-weight:700;display:flex;align-items:center;gap:8px}
.read h3{font-size:16px;margin:16px 0 6px;font-weight:700}
.read h2:first-child,.read h1:first-child,.read h3:first-child{margin-top:0}
.read p{margin:0 0 12px}
.read ul,.read ol{margin:0 0 12px;padding-left:2px}
.read li{position:relative;padding-left:20px;margin-bottom:7px}
.read li::before{content:"";position:absolute;left:4px;top:11px;width:5px;height:5px;border-radius:50%;background:#E5B79F}
.read ol{counter-reset:o}
.read ol li{counter-increment:o;padding-left:24px}
.read ol li::before{content:counter(o);background:none;left:0;top:0;width:auto;height:auto;font-size:12.5px;font-weight:700;color:var(--brand);font-variant-numeric:tabular-nums}
.read strong{color:var(--ink);font-weight:700;background:linear-gradient(180deg,transparent 62%,#FFE6D6 62%);padding:0 1px}
.read code{font-family:var(--mono);font-size:.9em;background:#F5F0E8;padding:1px 5px;border-radius:5px}
.read blockquote{
  margin:0 0 12px;padding:12px 16px;border-left:3px solid #F0B695;background:#FFFAF5;
  border-radius:0 10px 10px 0;font-size:15px;color:var(--ink-2);
}
.read .kv{background:#FBF7F1;border:1px solid var(--line);border-radius:12px;padding:12px 14px;margin-bottom:12px;font-size:15px}

.point-card{
  border:1px solid var(--line);border-radius:14px;padding:15px 16px;background:#fff;margin-bottom:10px;
}
.point-card .pc-t{font-size:14.5px;font-weight:700;display:flex;align-items:center;gap:8px;margin-bottom:6px}
.point-card .pc-b{font-size:14px;color:var(--ink-2);line-height:1.75}
.dot{width:8px;height:8px;border-radius:3px;flex:none}

/* AI 追问 */
.ask{display:flex;gap:10px;margin-top:16px;position:sticky;bottom:14px}
.ask input{flex:1;height:48px;border-radius:14px;border:1px solid var(--line);background:#fff;padding:0 16px;font-size:15px;outline:none;box-shadow:var(--shadow)}
.ask input:focus{border-color:#F0A98E;box-shadow:0 0 0 4px rgba(228,87,46,.08)}
.ask .btn{height:48px;border-radius:14px}
.qa{border-top:1px dashed var(--line);margin-top:18px;padding-top:14px}
.qa-q{display:flex;gap:9px;font-size:14.5px;font-weight:650;margin-bottom:10px}
.qa-q i{font-style:normal;color:var(--brand);font-weight:700;flex:none}
.qa-a{font-size:15.5px;line-height:1.9;color:var(--ink-2);padding-left:19px}

/* 打字光标 */
.caret{display:inline-block;width:7px;height:17px;background:var(--brand);border-radius:2px;vertical-align:-2px;animation:blink 1s steps(2) infinite}
@keyframes blink{50%{opacity:0}}

/* 答题 */
.qshell{max-width:820px;margin:0 auto}
.qbar{display:flex;align-items:center;gap:12px;margin:6px 0 16px}
.qbar-track{flex:1;height:7px;border-radius:99px;background:#EFE8DC;overflow:hidden}
.qbar-fill{height:100%;border-radius:99px;background:linear-gradient(90deg,#F08B5C,#E4572E);transition:width .3s}
.qnum{font-size:12.5px;color:var(--muted);font-variant-numeric:tabular-nums;flex:none}
.qcard{background:#fff;border:1px solid var(--line);border-radius:22px;padding:24px 26px 20px;box-shadow:var(--shadow)}
.qtype{display:flex;gap:8px;align-items:center;margin-bottom:12px}
.qstem{font-size:19px;line-height:1.75;font-weight:600;letter-spacing:.1px}
.qstem-sub{font-size:15px;font-weight:400;color:var(--ink-2);margin-top:8px;line-height:1.8}
.opts{display:flex;flex-direction:column;gap:10px;margin-top:20px}
.opt{
  display:flex;gap:12px;align-items:flex-start;padding:14px 16px;border-radius:14px;
  border:1.5px solid var(--line);background:#FCFAF6;cursor:pointer;transition:.14s;font-size:15.5px;line-height:1.6;
}
.opt:hover{border-color:#E0D3C0;background:#fff}
.opt .k{
  width:26px;height:26px;border-radius:8px;flex:none;display:grid;place-items:center;
  background:#fff;border:1px solid var(--line);font-size:13px;font-weight:700;color:var(--muted);
}
.opt.on{border-color:#E4572E;background:#FFF7F2;box-shadow:0 0 0 3px rgba(228,87,46,.07)}
.opt.on .k{background:var(--brand);border-color:var(--brand);color:#fff}
.opt.ok{border-color:#7CC9A6;background:#F2FBF6}
.opt.ok .k{background:var(--green);border-color:var(--green);color:#fff}
.opt.bad{border-color:#F0A8A8;background:#FEF4F4}
.opt.bad .k{background:var(--red);border-color:var(--red);color:#fff}
.opt:disabled{cursor:default}
.answer-box{margin-top:20px}
.answer-box textarea{min-height:110px;font-size:16.5px;line-height:1.9}
.qnav{display:flex;gap:10px;margin-top:20px;align-items:center}

.verdict{display:flex;align-items:center;gap:8px;font-size:14px;font-weight:700;margin-bottom:10px}
.verdict.ok{color:var(--green)}
.verdict.bad{color:var(--red)}
.verdict.mid{color:var(--amber)}
.explain{
  margin-top:14px;padding:14px 16px;border-radius:14px;background:#FBF7F1;border:1px solid var(--line);
  font-size:14.5px;line-height:1.85;color:var(--ink-2);
}
.explain b{color:var(--ink)}
.explain .lbl{font-size:11.5px;letter-spacing:1px;color:var(--faint);font-weight:700;display:block;margin-bottom:5px}

/* 成绩 */
.score-hero{display:flex;align-items:center;gap:22px;flex-wrap:wrap}
.score-big{font-size:52px;font-weight:800;letter-spacing:-2px;line-height:1}
.score-big small{font-size:16px;font-weight:600;color:var(--faint);letter-spacing:0;margin-left:2px}
.bars{display:flex;flex-direction:column;gap:11px}
.bar-row{display:grid;grid-template-columns:88px 1fr 46px;gap:12px;align-items:center;font-size:13px}
.bar-track{height:9px;border-radius:99px;background:#F1EAE0;overflow:hidden}
.bar-fill{height:100%;border-radius:99px;background:linear-gradient(90deg,#F0A57C,#E4572E)}
.bar-fill.g{background:linear-gradient(90deg,#7CC9A6,#2E9E6B)}
.bar-fill.b{background:linear-gradient(90deg,#8FB4F2,#2F6FEB)}
.bar-row b{font-variant-numeric:tabular-nums;text-align:right;font-size:12.5px;color:var(--ink-2)}

/* 骨架 */
.skel{background:linear-gradient(90deg,#F3EEE6 25%,#FAF6F0 37%,#F3EEE6 63%);background-size:400% 100%;animation:shimmer 1.4s ease infinite;border-radius:8px;height:14px;margin-bottom:10px}
@keyframes shimmer{0%{background-position:100% 50%}100%{background-position:0 50%}}

/* 提示 & 弹层 */
.toast{
  position:fixed;left:50%;bottom:28px;transform:translate(-50%,20px);z-index:200;
  background:rgba(28,25,23,.94);color:#fff;font-size:13.5px;padding:11px 18px;border-radius:12px;
  opacity:0;pointer-events:none;transition:.24s;max-width:86vw;text-align:center;
}
.toast.show{opacity:1;transform:translate(-50%,0)}

.gate{
  position:fixed;inset:0;z-index:150;display:grid;place-items:center;padding:20px;
  background:rgba(247,244,238,.92);backdrop-filter:blur(10px);overflow:auto;
}
.gate[hidden]{display:none}
.gate-card{
  width:100%;max-width:410px;background:#fff;border:1px solid var(--line);border-radius:24px;
  padding:30px 28px 26px;box-shadow:var(--shadow-lg);text-align:center;
}
.gate-brand .brand-mark{width:52px;height:52px;border-radius:16px;font-size:24px;margin:0 auto 14px}
.gate-card h1{font-size:24px;font-weight:750;letter-spacing:-.3px}
.setup-title{text-align:left}
.gate-sub{font-size:13px;color:var(--muted);line-height:1.7;margin:10px 0 22px}
.gate-tabs{display:flex;gap:4px;background:#F4EFE7;padding:4px;border-radius:12px;margin-bottom:18px}
.gate-tab{flex:1;height:34px;border:none;background:transparent;border-radius:9px;font-size:13px;font-weight:600;color:var(--muted);cursor:pointer}
.gate-tab.active{background:#fff;color:var(--ink);box-shadow:0 1px 3px rgba(0,0,0,.06)}
.gate .field{text-align:left}
.gate-err{color:var(--red);font-size:12.5px;min-height:18px;margin:0 0 8px;text-align:left}
.gate-tip{font-size:11.5px;color:var(--faint);line-height:1.7;margin-top:14px}

/* 空状态 */
.empty{display:flex;flex-direction:column;align-items:center;gap:10px;padding:56px 20px;text-align:center}
.empty .e-ico{width:56px;height:56px;border-radius:18px;background:#F6F1E9;display:grid;place-items:center;font-size:24px}
.empty b{font-size:15px}
.empty span{font-size:13px;color:var(--muted);max-width:38ch;line-height:1.7}

/* 提示条 */
.tip{
  display:flex;gap:10px;padding:12px 14px;border-radius:12px;font-size:12.5px;line-height:1.7;
  background:#FFFBF3;border:1px solid #F6E7CB;color:#8A6416;
}
.tip b{font-weight:700}

/* 分割 */
.hr{height:1px;background:var(--line);margin:18px 0;border:none}
.seg{display:flex;gap:6px;overflow:auto;padding-bottom:2px;scrollbar-width:none}
.seg::-webkit-scrollbar{display:none}

/* 版本卡 */
.ver-card{
  display:flex;align-items:center;gap:14px;padding:15px 16px;border:1.5px solid var(--line);
  border-radius:16px;background:#fff;cursor:pointer;transition:.15s;
}
.ver-card:hover{border-color:#E0D3C0}
.ver-card.on{border-color:var(--brand);background:#FFF9F5;box-shadow:0 0 0 3px rgba(228,87,46,.06)}
.ver-radio{width:20px;height:20px;border-radius:50%;border:1.5px solid #D9CDBC;flex:none;display:grid;place-items:center}
.ver-card.on .ver-radio{border-color:var(--brand)}
.ver-card.on .ver-radio::after{content:"";width:10px;height:10px;border-radius:50%;background:var(--brand)}
.ver-name{font-size:14.5px;font-weight:650}
.ver-meta{font-size:11.5px;color:var(--muted);margin-top:2px}

/* 移动端 */
@media (max-width:900px){
  .app{grid-template-columns:1fr}
  .side{display:none}
  .view{padding:4px 16px 96px}
  .topbar{padding:12px 16px}
  .tabbar{
    display:grid;grid-template-columns:repeat(5,1fr);position:fixed;left:0;right:0;bottom:0;z-index:40;
    background:rgba(255,255,255,.94);backdrop-filter:blur(16px);border-top:1px solid var(--line);
    padding:6px 4px calc(6px + env(safe-area-inset-bottom));
  }
  .tabbar a{display:flex;flex-direction:column;align-items:center;gap:2px;padding:6px 0;color:var(--faint);font-size:10.5px;font-weight:600}
  .tabbar a i{font-size:17px;font-style:normal;line-height:1}
  .tabbar a.active{color:var(--brand)}
  .g2,.g3,.g4{grid-template-columns:1fr}
  .g3.keep,.g2.keep{grid-template-columns:repeat(2,minmax(0,1fr))}
  .page-title{font-size:20px}
  .hero{padding:20px 18px 18px;border-radius:20px}
  .hero h2{font-size:21px}
  .lesson-title{font-size:21px}
  .qstem{font-size:17.5px}
  .read{font-size:16px}
  .card-pad{padding:16px}
  .qcard{padding:18px 16px 16px}
  .score-big{font-size:42px}
  .toast{bottom:84px}
}
@media (max-width:380px){
  .g3.keep,.g2.keep{grid-template-columns:1fr}
}
@media print{
  .side,.topbar,.tabbar,.ask{display:none}
}