:root{
  --red:#c8102e; --red-soft:#fde8ec; --navy:#14213d; --navy-soft:#2a3a63;
  --bg:#f3f5f8; --card:#ffffff; --line:#e7eaf0; --text:#1f2733; --muted:#7a8699;
  --green:#1f9d57; --green-soft:#e6f6ee; --gold:#d4a017;
  --shadow:0 2px 10px rgba(20,33,61,.06); --shadow-lg:0 8px 30px rgba(20,33,61,.10);
  --radius:14px;
}
*{box-sizing:border-box;-webkit-tap-highlight-color:transparent;}
html,body{margin:0;padding:0;}
body{
  font-family:-apple-system,BlinkMacSystemFont,"PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;
  background:var(--bg); color:var(--text); line-height:1.6;
  padding-bottom:calc(64px + env(safe-area-inset-bottom));
  -webkit-font-smoothing:antialiased;
}
button{font-family:inherit;cursor:pointer;border:none;background:none;color:inherit;}
img{max-width:100%;}

/* ===== Header ===== */
.app-header{
  position:sticky;top:0;z-index:30;
  background:linear-gradient(120deg,var(--navy),#22335f);
  color:#fff;padding:14px 16px calc(14px + env(safe-area-inset-top)) 16px;
  box-shadow:var(--shadow);
}
.brand{display:flex;align-items:center;gap:12px;}
.brand-logo{
  width:42px;height:42px;border-radius:12px;background:var(--red);
  display:grid;place-items:center;font-size:22px;font-weight:800;color:#fff;
  box-shadow:0 4px 12px rgba(200,16,46,.4);
}
.brand-text h1{font-size:18px;margin:0;font-weight:800;letter-spacing:.5px;}
.brand-text p{margin:2px 0 0;font-size:12px;opacity:.78;}

/* ===== View container ===== */
.view{padding:14px 14px 110px;max-width:720px;margin:0 auto;}
.section-title{font-size:16px;font-weight:800;margin:18px 2px 10px;display:flex;align-items:center;gap:8px;}
.section-title::before{content:"";width:4px;height:16px;background:var(--red);border-radius:2px;}
.muted{color:var(--muted);font-size:13px;}

/* ===== Cards ===== */
.card{background:var(--card);border-radius:var(--radius);box-shadow:var(--shadow);padding:16px;margin-bottom:12px;}
.card-row{display:flex;align-items:center;gap:12px;}
.grid-2{display:grid;grid-template-columns:1fr 1fr;gap:12px;}
.grid-3{display:grid;grid-template-columns:repeat(3,1fr);gap:10px;}

/* ===== Home hero ===== */
.hero{
  background:linear-gradient(135deg,var(--red),#e23a52);
  color:#fff;border-radius:18px;padding:20px 18px;margin-bottom:14px;
  box-shadow:0 10px 26px rgba(200,16,46,.28);position:relative;overflow:hidden;
}
.hero h2{margin:0 0 6px;font-size:22px;font-weight:900;letter-spacing:1px;}
.hero p{margin:0;opacity:.92;font-size:13px;line-height:1.7;}
.hero .stats{display:flex;gap:14px;margin-top:16px;}
.hero .stat{flex:1;text-align:center;background:rgba(255,255,255,.15);border-radius:12px;padding:10px 6px;backdrop-filter:blur(2px);}
.hero .stat b{display:block;font-size:22px;font-weight:900;line-height:1.1;}
.hero .stat span{font-size:11px;opacity:.9;}

/* quick entries */
.entry{display:flex;flex-direction:column;align-items:center;gap:6px;padding:14px 6px;border-radius:14px;background:var(--card);box-shadow:var(--shadow);transition:transform .15s;}
.entry:active{transform:scale(.96);}
.entry .ico{width:46px;height:46px;border-radius:13px;display:grid;place-items:center;font-size:24px;}
.entry span{font-size:13px;font-weight:700;}
.entry .sub{font-size:11px;color:var(--muted);font-weight:500;}

/* ===== Buttons ===== */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:6px;padding:12px 18px;border-radius:12px;font-weight:800;font-size:15px;transition:.15s;}
.btn:active{transform:scale(.97);}
.btn-primary{background:var(--red);color:#fff;box-shadow:0 6px 16px rgba(200,16,46,.3);}
.btn-navy{background:var(--navy);color:#fff;}
.btn-ghost{background:#eef1f6;color:var(--navy);}
.btn-outline{border:1.5px solid var(--red);color:var(--red);background:#fff;}
.btn-block{width:100%;}
.btn-sm{padding:8px 12px;font-size:13px;border-radius:10px;}

/* ===== Filters ===== */
.chips{display:flex;flex-wrap:wrap;gap:8px;margin:6px 0 4px;}
.chip{padding:7px 13px;border-radius:20px;background:#eef1f6;color:var(--navy);font-size:13px;font-weight:600;border:1.5px solid transparent;}
.chip.active{background:var(--red);color:#fff;border-color:var(--red);}
.field{margin-bottom:14px;}
.field>label{font-size:13px;font-weight:700;color:var(--navy);display:block;margin-bottom:6px;}

/* ===== Question ===== */
.q-meta{display:flex;gap:8px;flex-wrap:wrap;margin-bottom:10px;}
.tag{font-size:11px;padding:3px 9px;border-radius:8px;background:var(--red-soft);color:var(--red);font-weight:700;}
.tag.year{background:#eaf0fb;color:var(--navy-soft);}
.tag.type{background:#fff3e0;color:#b26a00;}
.q-stem{font-size:16px;line-height:1.85;white-space:pre-wrap;word-break:break-word;margin:4px 0 14px;font-weight:600;color:#222;}
.options{display:flex;flex-direction:column;gap:10px;}
.opt{
  display:flex;gap:11px;align-items:flex-start;padding:13px 14px;border-radius:12px;
  background:#f7f9fc;border:1.5px solid var(--line);transition:.15s;font-size:15px;
}
.opt:active{transform:scale(.99);}
.opt .opt-key{flex:0 0 26px;width:26px;height:26px;border-radius:8px;background:#e3e8f0;color:var(--navy);display:grid;place-items:center;font-weight:800;font-size:14px;}
.opt.sel{background:var(--red-soft);border-color:var(--red);}
.opt.sel .opt-key{background:var(--red);color:#fff;}
.opt.correct{background:var(--green-soft);border-color:var(--green);}
.opt.correct .opt-key{background:var(--green);color:#fff;}
.opt.wrong{background:#fdecec;border-color:#e08585;}
.opt.wrong .opt-key{background:#e23a52;color:#fff;}
.opt-text{flex:1;min-width:0;}

/* answer feedback */
.feedback{margin-top:14px;border-radius:12px;padding:14px;display:none;}
.feedback.show{display:block;animation:fade .3s;}
.feedback.ok{background:var(--green-soft);}
.feedback.no{background:#fdecec;}
.fb-head{font-weight:800;margin-bottom:8px;display:flex;align-items:center;gap:8px;}
.fb-ans{font-size:15px;margin-bottom:8px;}
.fb-ans b{color:var(--red);font-size:18px;letter-spacing:1px;}
.analysis{font-size:14px;line-height:1.8;color:#334;white-space:pre-wrap;word-break:break-word;}
.analysis .ttl{font-weight:800;color:var(--navy);display:block;margin-bottom:4px;}

/* progress */
.q-progress{display:flex;justify-content:space-between;align-items:center;font-size:12px;color:var(--muted);margin-bottom:8px;}
.bar{height:7px;border-radius:6px;background:#e3e8f0;overflow:hidden;margin-bottom:14px;}
.bar>i{display:block;height:100%;background:linear-gradient(90deg,var(--red),#e23a52);transition:width .3s;}

/* ===== Summary / Report ===== */
.score-big{font-size:54px;font-weight:900;line-height:1;color:var(--red);}
.level-badge{display:inline-block;padding:6px 16px;border-radius:20px;font-weight:800;font-size:15px;color:#fff;background:var(--gold);}
.kpis{display:grid;grid-template-columns:repeat(3,1fr);gap:10px;margin:12px 0;}
.kpi{background:#f7f9fc;border-radius:12px;padding:12px 8px;text-align:center;}
.kpi b{display:block;font-size:20px;color:var(--navy);}
.kpi span{font-size:11px;color:var(--muted);}
.subject-list{margin-top:6px;}
.subj-line{display:flex;align-items:center;gap:10px;margin:9px 0;font-size:14px;}
.subj-line .nm{width:64px;flex:0 0 64px;font-weight:700;}
.subj-line .meter{flex:1;height:10px;border-radius:6px;background:#e3e8f0;overflow:hidden;}
.subj-line .meter>i{display:block;height:100%;background:var(--green);}
.subj-line .pct{width:48px;text-align:right;font-weight:700;color:var(--navy);}

/* tips */
.tip{display:flex;gap:10px;padding:11px 12px;border-radius:11px;background:#fff8e9;margin:8px 0;font-size:13.5px;line-height:1.6;}
.tip .ti{flex:0 0 22px;}

/* ===== Bank ===== */
.bank-item{padding:14px;border-radius:12px;background:#fff;box-shadow:var(--shadow);margin-bottom:11px;}
.bank-item .q-meta{margin-bottom:8px;}
.bank-ans{margin-top:10px;font-size:14px;}
.bank-ans .ans-keys{color:var(--red);font-weight:800;letter-spacing:1px;}
.search{display:flex;gap:8px;margin-bottom:12px;}
.search input{flex:1;padding:11px 14px;border-radius:12px;border:1.5px solid var(--line);font-size:14px;outline:none;}
.search input:focus{border-color:var(--red);}
.reveal-btn{margin-top:8px;}

/* ===== Mine ===== */
.hist-item{display:flex;justify-content:space-between;align-items:center;padding:13px 14px;border-radius:12px;background:#fff;box-shadow:var(--shadow);margin-bottom:10px;}
.hist-item .h-main{font-weight:700;font-size:15px;}
.hist-item .h-sub{font-size:12px;color:var(--muted);margin-top:2px;}
.acc-pill{font-weight:800;font-size:16px;color:var(--red);}
.empty{text-align:center;color:var(--muted);padding:40px 10px;font-size:14px;}
.empty .em-ico{font-size:40px;display:block;margin-bottom:8px;}

/* radar */
.radar-wrap{display:flex;justify-content:center;padding:6px 0;}
.note{font-size:12px;color:var(--muted);background:#f0f3f8;border-radius:10px;padding:10px 12px;margin-top:10px;line-height:1.6;}

/* loading */
.center-msg{text-align:center;padding:50px 20px;color:var(--muted);}
.spinner{width:34px;height:34px;border:3px solid #e3e8f0;border-top-color:var(--red);border-radius:50%;margin:0 auto 12px;animation:spin .8s linear infinite;}
@keyframes spin{to{transform:rotate(360deg);}}
@keyframes fade{from{opacity:0;transform:translateY(6px);}to{opacity:1;transform:none;}}

/* ===== Bottom nav ===== */
.bottom-nav{
  position:fixed;left:0;right:0;bottom:0;z-index:40;
  display:flex;background:#fff;border-top:1px solid var(--line);
  padding:6px 4px calc(6px + env(safe-area-inset-bottom));
  box-shadow:0 -2px 14px rgba(20,33,61,.08);
}
.nav-btn{flex:1;display:flex;flex-direction:column;align-items:center;gap:2px;padding:4px 0;color:var(--muted);font-size:11px;font-weight:600;transition:.15s;}
.nav-btn .nav-ico{font-size:20px;line-height:1.1;filter:grayscale(.3);}
.nav-btn.active{color:var(--red);}
.nav-btn.active .nav-ico{filter:none;transform:translateY(-1px);}

/* toast */
.toast{position:fixed;left:50%;bottom:90px;transform:translateX(-50%);background:rgba(20,33,61,.92);color:#fff;padding:10px 18px;border-radius:22px;font-size:14px;z-index:99;opacity:0;transition:.25s;pointer-events:none;}
.toast.show{opacity:1;}

/* katex overflow */
.katex{font-size:1.02em;}
.q-stem .katex-display,.analysis .katex-display,.opt-text .katex-display{margin:6px 0;overflow-x:auto;overflow-y:hidden;}